The Well-Rounded Mama

Tuesday, September 11, 2012

The Dangers of Estimating Fetal Weight Near Term

Here's a new, interesting study that shows that the routine practice of ordering a fetal weight estimate near term can have negative consequences.

Background: Many care providers order an ultrasound to estimate the baby's weight when the mother is near term, even though research shows this is not a very accurate way to predict the baby's weight.

Women with babies predicted to be big often are pressured to schedule a planned cesarean to avoid the possibility of shoulder dystocia (shoulders getting stuck, causing injury to the baby), despite little research to show that a cesarean improves outcome.

Or they are encouraged to induce labor early "while the baby is smaller," even though research shows that this actually may increase the risk for cesarean.

Here is a new study that shows that even just doing the fetal-weight ultrasound in the first place may increase the risk for cesarean.

Why? Probably because knowledge of the results (and nervousness over fetal size) changes the behavior of the care provider so that they have a lower surgical threshold during labor.

This is particularly an issue for women of size. Even though the majority of "obese" women do not have big babies at all, we do tend to have bigger babies on average than "normal" weight women. This makes care providers nervous. And since many believe that fat women eat mostly junk food or are practically diabetic anyhow, this increases their fear of big babies even more. So many providers routinely order ultrasounds to estimate fetal weight near term in the pregnancies of obese women.

In this most recent study, 50% of all pregnant women had an ultrasound that calculated Estimated Fetal Weight (EFW) within a month of delivery. Those that did had a higher cesarean rate than those who didn't, especially those whose babies were predicted to be big by EFW.

The rate of EFW ulstraounds is probably even higher in obese women. How does that then affect our cesarean rates? It is likely another example of management variables that result in increased cesarean rates in obese women. Yet this is a management variable that can be modified.

An ultrasound to estimate fetal weight near term does not improve outcomes and is a risk factor for an increased cesarean rate.

References

Am J Obstet Gynecol. 2012 Jul 9. [Epub ahead of print] Estimated fetal weight by ultrasound: a modifiable risk factor for cesarean delivery? Little SE, Edlow AG, Thomas AM, Smith NA. PMID: 22902073

OBJECTIVE: The purpose of this study was to investigate whether knowledge of ultrasound-obtained estimated fetal weight (US-EFW) is a risk factor for cesarean delivery (CD).
STUDY DESIGN: Retrospective cohort from a single center in 2009-2010 of singleton, term live births. CD rates were compared for women with and without US-EFW within 1 month of delivery and adjusted for potential confounders.
RESULTS: Of the 2329 women in our cohort, 50.2% had US-EFW within 1 month of delivery. CD was significantly more common for women with US-EFW (15.7% vs 10.2%; P < .001); after we controlled for confounders, US-EFW remained an independent risk factor for CD (odds ratio, 1.44; 95% confidence interval, 1.1-1.9). The risk increased when US-EFW was >3500 g (odds ratio, 1.8; 95% confidence interval, 1.3-2.7).
CONCLUSION: Knowledge of US-EFW, above and beyond the impact of fetal size itself, increases the risk of CD. Acquisition of US-EFW near term appears to be an independent and potentially modifiable risk factor for CD.

Am J Obstet Gynecol. 2009 Mar;200(3):340.e1-3. Overestimation of fetal weight by ultrasound: does it influence the likelihood of cesarean delivery for labor arrest? Blackwell SC, Refuerzo J, Chadha R, Carreno CA. PMID: 19254597

OBJECTIVE: We sought to determine whether the overestimation of ultrasound-derived estimated fetal weight (EFW) is associated with increased diagnosis of labor arrest. STUDY DESIGN: This is a historical cohort study of nulliparous women with term pregnancies who underwent bedside ultrasound examination for EFW before labor induction. Labor outcomes of women with EFW overestimation > 15% the actual birthweight were compared with those with EFW not overestimated. RESULTS: Overestimation of EFW occurred in 9.5% of cases (23/241). The rate of cesarean delivery (CD) for labor arrest was higher for those with EFW overestimation (34.8% vs 13.3%; P = .01) even though there were no differences in length of the induction duration. After adjusting for confounding factors, EFW overestimation remained associated with CD for labor arrest (odds ratio, 4.8; 95% confidence interval, 1.5-15.2). CONCLUSION: Our finding suggests that an overestimation of EFW may be associated with a lower threshold for CD for labor arrest.

Am J Obstet Gynecol. 1995 Oct;173(4):1215-9. Fetal macrosomia: does antenatal prediction affect delivery route and birth outcome? Weeks JW, Pitman T, Spinnato JA 2nd. PMID: 7485323

OBJECTIVE: Our purpose was to determine whether clinical or ultrasonographic prediction of fetal macrosomia influences subsequent delivery route and birth outcome in a clinical setting where macrosomia is not considered an indication for cesarean delivery. STUDY DESIGN: The hospital records of 504 patients delivered of infants weighing > or = 4200 gm between October 1989 and March 1994 were reviewed. Statistical comparisons were made between patients in whom fetal macrosomia was predicted before delivery (n = 102) and those in whom it was not (n = 402). Cesarean delivery, shoulder dystocia, and birth trauma rates were the variables of interest. RESULTS: Cesarean sections were performed in 52% of the "predicted" group deliveries and in 30% of the "not predicted" group (p < 0.01). The increased cesarean delivery rate in the predicted group appeared to be related to an increased incidence of labor inductions (42.5% vs 26.6%, p = 0.005) and a greater proportion of failed inductions. The proportion of patients delivered by cesarean section without a trial of labor was similar in the predicted and not predicted groups (14.7% vs 10.2%, p = 0.21). There was no significant differences in the incidence of shoulder dystocia or the occurrence of birth trauma. CONCLUSIONS: The antenatal prediction of fetal macrosomia is associated with a marked increase in cesarean deliveries without a significant reduction in the incidence of shoulder dystocia or fetal injury. Ultrasonography and labor induction for patients at risk for fetal macrosomia should be discouraged.

Eur J Obstet Gynecol Reprod Biol. 2002 Oct 10;105(1):20-4. Clinical and ultrasonographic weight estimation in large for gestational age fetus. Weiner Z, et al. PMID: 12270559

OBJECTIVE: To examine prospectively the effect on pregnancy outcome of a management protocol, that adds ultrasonographic weight estimation in fetuses suspected clinically as large. STUDY DESIGN: Prospective follow up study of all singleton deliveries during a 1 year period. All patients underwent routine clinical estimation of fetal weight. When clinical estimation of fetal weight was > or = 3700 g, patients were referred for ultrasonographic estimation of fetal weight. When the latter was > or = 4000 g the patient was informed about the risks of birth trauma. Cesarean section was recommended only when > or = 4500 g. Ultrasonography was repeated every 4 days when possible. Predictive values of clinical and ultrasonographic estimations of fetal weight for diagnosing macrosomia, defined for the purpose of this study as 4000 g or more, and their effect on the rate of cesarean sections. RESULTS: Five hundred fifty-five (14.4%) out of 3844 singletons were estimated as 3700 g or more. Only 315 fetuses had ultrasonographic estimation of weight within 3 days of delivery. The sensitivity of clinical and ultrasonographic prediction of macrosomia was 68 and 58%, respectively. Cesarean section rate in newborns weighing 4000 g or more was 22% when macrosomia was clinically suspected compared to 11% when it was not (P<0.05). In fetuses estimated ultrasonographically as 4000 g or larger the cesarean section rate was doubled (50.7% versus 24.9%, P<0.05) compared to those estimated as smaller than 4000 g, although actual weight of 4500 g or more was recorded in 10.6 and 8.5% of these groups, respectively. There were no cases of shoulder dystocia in macrosomic babies when macrosomia was not detected by ultrasound compared to two cases of shoulder dystocia (2.7%) when macrosomia was detected by ultrasound. CONCLUSION: Antenatal suspicion of macrosomia increased the cesarean section rate while the associated improvement in pregnancy outcome remains questionable. The contribution of ultrasound, added to routine clinical estimation of fetal weight, was clinically insignificant apart from a further increase in cesarean section rate.

Arch Gynecol Obstet. 2008 Sep;278(3):225-30. Epub 2008 Feb 26. Suspected macrosomia? Better not tell. Sadeh-Mestechkin D, et al. PMID: 18299867

OBJECTIVE: To evaluate the management policy of delivery in a suspected macrosomic fetus and to describe the outcome of this policy. STUDY DESIGN: For this prospective observational study we followed the management by reviewing the medical records of 145 women and their infants. The study population included women at term admitted to the obstetrics department with suspected macrosomic infants, as was diagnosed by an obstetrician and/or by fetal sonographic weight estimation of > or =4,000 g. The comparison group (n = 5,943) consisted of all women who gave birth during the data collection period. RESULTS: Induction of labor and cesarean delivery rates in the macrosomic pregnancies (actual birth weight >4,000 g) of the study group were significantly higher when compared with the macrosomic pregnancies of the comparison group. When comparing the non-macrosomic to the macrosomic pregnancies (actual birth weight </>4,000 g) of the study group no significant difference was demonstrated regarding maternal or infant complications. The sensitivity, specificity and positive predictive value of the methods used for detecting macrosomia were 21.6, 98.6 and 43.5%, respectively. CONCLUSION: Our ability to predict macrosomia is poor. Our management policy of suspected macrosomic pregnancies raises induction of labor and cesarean delivery rates without improving maternal or fetal outcome.

Am J Obstet Gynecol. 2006 Sep;195(3):657-72. Epub 2006 Apr 21. Shoulder dystocia: the unpreventable obstetric emergency with empiric management guidelines. Gherman RB, et al. PMID: 16949396

OBJECTIVE: Much of our understanding and knowledge of shoulder dystocia has been blurred by inconsistent and scientific studies that are of limited scientific quality. In an evidence-based format, we sought to answer the following questions: (1) Is shoulder dystocia predictable? (2) Can shoulder dystocia be prevented? (3) When shoulder dystocia does occur, what maneuvers should be performed? and (4) What are the sequelae of shoulder dystocia? STUDY DESIGN: Electronic databases, including PUBMED and the Cochrane Database, were searched using the key word "shoulder dystocia." We also performed a manual review of articles included in the bibliographies of these selected articles to further define articles for review. Only those articles published in the English language were eligible for inclusion. RESULTS: There is a significantly increased risk of shoulder dystocia as birth weight linearly increases. From a prospective point of view, however, prepregnancy and antepartum risk factors have exceedingly poor predictive value for the prediction of shoulder dystocia. Late pregnancy ultrasound likewise displays low sensitivity, decreasing accuracy with increasing birth weight, and an overall tendency to overestimate the birth weight. Induction of labor for suspected fetal macrosomia has not been shown to alter the incidence of shoulder dystocia among nondiabetic patients. The concept of prophylactic cesarean delivery as a means to prevent shoulder dystocia and therefore avoid brachial plexus injury has not been supported by either clinical or theoretic data....

Monday, September 3, 2012

Canning: Pecking About Pectins

Different brands of pectin; image from pickyourown.org

We've been talking about canning and preserving as an end-of-summer change of pace for the blog. Today, let's talk about pectins.

Previously, we talked a little about things that keep people from trying canning, which are usually safety fears or just pure lack of knowledge about how to can.

We reminded everyone that high-acid fruit jams, processed in a boiling water bath, are a very safe form of canning, unlikely to harm anyone because spoilage would be obvious (mold or a fermented smell). Thus, jams are a great place for beginners to start.

We also shared some resources for learning how to can, good books and websites for canning, online tutorials, and how to find canning classes in your local area.

One question that often arises in canning is the difference between the different types of pectin, and that can definitely be confusing. So let's try to break it down a little bit now.

What is Pectin?

Pectin is plant fiber that is used as a thickening agent for jams and jellies. Here is one website's summary:

By definition, pectin is a structural heteropolysaccharide found in the walls of plants that forms a colloidal system when combined with water. In simpler terms, pectin is a soluble fiber that forms a gel when you add water to it. Some plants have more pectin in them, some less. Apples and citrus fruits have the highest concentrations of pectin in them and are oftentimes the sources for what you will find on the shelves at your grocery store.

Knowledge of the uses of pectin has been around for a long time, as discussed here:

Jams and Jellies have been produced for many years, at least since the 18th Century. Recipes were published in the "London Housewife's Family Companion" of 1750 which described jellies made from apple, currant, and quince, all fruits rich in gelling pectin.

Pectin was first isolated in the 1820s, and shown to be the key to making jams and jellies.
Gradually, people mixed pectin rich fruits or fruit extracts with fruits which do not set jams well - strawberry with gooseberry or with red currant, for example. Extracts of apple peels and cores were also used for "difficult to set" jams.

Commercial jam producers sought further supplies of pectin source materials. In Germany, apple juice producers started to dry the pomace residue left after pressing juice for sale to jam makers, who would cook the pomace in water with or without fruit juice to make a jellying juice.

The first commercial production of a liquid pectin extract was recorded in 1908 in Germany, and the process spread rapidly to the United States, where a classic patent was obtained by Douglas (US Pat. 1.082,682, 1913). This was followed by a rapid growth of the pectin industry in the United States, and also somewhat later in Europe.

In recent years, the centre of production has moved to Europe and to citrus-producing countries like Mexico and Brazil.

There are several different types of pectin and each works a little differently. The main two types of pectin are high methoxyl pectin and low methoxyl pectin:

The high methoxyl pectin needs acid and sugar for it to work and is most commonly used for traditional fruit preserves. Low methoxyl pectin needs calcium present for the gelling process to work, which makes it better for low or no sugar preserves.

This is a crucial difference, so let's discuss it a bit more.

High Methoxyl Pectins

High methoxyl pectins are the kind most people probably think of when they think of canning.

High methoxyl pectins are easily found in most supermarkets. Common brands are Sure-Jell, Ball, Certo, MCP, and many others.

Different brands have differing processing requirements. If you are going to make a recipe from the box, follow the recipes in that brand's box only. Don't swap brands because recipes are formulated specifically for that brand and its unique requirements.

Dry and liquid forms of high methoxyl pectins are not interchangeable either. Each has their own advantages, and which you use is mostly personal preference. Certo is the most common liquid pectin you'll find, but Ball also makes a liquid pectin which some people prefer.

There are also rapid-set and slow-set high methoxyl pectins. The difference is in the Degree of Esterification (DE). The rapid-set ones have a high DE and are used for products where you want chunks of fruit suspended in a gel, as in marmalades. Slower-set ones have a slightly lower DE and are good for clear jellies.

One disadvantage to high methoxyl pectins is that they need sugar to set up (jell), and therefore you can't alter the amount of sugar that's in the recipe. The recipe has been tested to see just how much sugar is needed to make the jam set up properly, so if you lower the sugar amount you will get runny jam.

Another nit-picky detail about high methoxyl pectins is that they are very finicky about changes to a recipe. If you try to make a double batch of jam, they won't set up well. Definitely make two separate batches rather than double a recipe. Also don't tweak the ingredients very much; a little bit of change in spices can be tolerated, but anything more will probably also affect the ability of the pectin to set up.

High methoxyl pectins need inordinate amounts of sugar. Usually the sugar concentration required is above 55 percent, meaning that there is more sugar than fruit in the recipe, causing the jam to be super-sweet. Many people (including me) don't like this.

No, I'm not trying to lose weight, and no, I'm not diabetic, but this is too much for me. My sweet tooth is absolutely overwhelmed by the sweetness in some of these full-sugar recipes, and I don't think that much sugar is good for your body.

If you are like me and want to lower the amount of sugar in your jams, consider a low methoxyl pectin instead.

Low Methoxyl Pectins

Low methoxyl pectins are less commonly used and harder to find. However, they offer far more flexibility in the amount of sugar that's required, which is increasing their popularity quickly.

Low methoxyl pectin is made by subjecting high methoxyl pectins to a de-estrification process. High methoxyl pectins have a DE of more than 50%, and low methoxyl pectins have a DE of less than 50%.

A low DE means that low methoxyl pectins are responsive to calcium ions, unlike high methoxyl pectins, which lets them jell food differently. Canning with low methoxyl pectin involves adding calcium in order to activate the jelling properties of this pectin.

This is the biggest difference between the two pectins. High methoxyl pectins jell due to the interaction between the pectin, sugar, and acid, while low methoxyl pectins jell due to interaction with added calcium, thus requiring much less sugar.

Sure-Jell makes a low methoxyl pectin (available in the PINK box) in addition to its high methoxyl pectin (available in the YELLOW box). In the Sure-Jell pink box, the calcium has already been added to the pectin powder and stabilized with dextrose, so the cook doesn't have an extra step in the canning process.

Many people like the low-sugar Sure-Jell because that extra step is done for them. However, Sure-Jell's "low sugar" recipes still use quite a bit of sugar ─ about 3 cups of sugar for every 4 cups of fruit. Many people would like to use even less. So they turn to Pomona Pectin instead.

Pomona Pectin is the brand of low methoxyl pectin that will best accommodate low sugar recipes. This type is "amidated" through an additional processing step, which lowers the degree of esterification even more. Because of this, it is even more responsive to calcium for jelling, rendering the amount of sugar irrelevant except for taste.

Thus, cooks using Pomona Pectin can use as much or as little sugar (including no sugar at all) as they prefer. Most jammers end up using somewhere around 1/2 - 1 cup of sugar for every 4 cups of fruit with this pectin, but you can vary the amount of sugar used according to your taste, which is a flexibility no other pectin has.

In addition, since the jelling properties are not dependent on sugar, you can also use different types of sweeteners, like honey, maple syrup, fructose, agave, fruit juice, etc. Or you can use artificial sweeteners like Stevia if you need to watch your carb intake super carefully. For diabetics, people with PCOS, or people with cane sugar allergies, this flexibility is huge.

However, the trade-off is that the calcium needed is not pre-added to Pomona, so you have to make a calcium-water mixture beforehand and then add it near the end of jamming. This calcium water thing seems strange if you've not used it before, but it's really not a big deal. Here is information about using calcium water from the Pomona website:

What are the ingredients in the monocalcium phosphate powder that comes with Pomona’s Pectin? The monocalcium phosphate powder that comes in its own packet when you purchase Pomona’s is a food-grade rock mineral source of calcium made up of two minerals, calcium and phosphorous. The food industry uses it as a yeast nutrient in baking, an acidulant in baking powder, and a mineral supplement.

What is calcium water? Calcium water is a solution of some of the monocalcium phosphate powder that comes with Pomona’s Pectin and water.

How do I make calcium water? Put 1/2 teaspoon white calcium powder and 1/2 cup water in a small, clear jar with a lid. Shake well before using. Store in the refrigerator between uses. Calcium water lasts a number of months. These same instructions are on the directions and recipe sheet that comes with Pomona’s Pectin.

How long will calcium water keep? Calcium water should be stored in the refrigerator. It will last a number of months. When you take your jar out of the refrigerator, look at it before you shake it. You should see white powder settled at the bottom of the jar and clear water above that. If you see any other colors in the jar, discard the calcium water.

There is a bit of a learning curve involved in using Pomona Pectin. Personally, I found that the directions included in the Pomona box were very confusing for a first-timer. It took us a while in our canning class to figure their directions out, and even our teachers were a little confused by some of their phrasing. But eventually we figured it all out.

If you learned to make jam using high methoxyl pectins, it's confusing at first to switch to a different order of mixing things (you add the pectin to the sweetener first, not the fruit, or it will clump). You also have an extra step, adding the calcium water). However, the advantages that Pomona offers outweighs the confusing directions and the extra steps.

For example, Pomona claims its pectin lasts indefinitely if stored properly. High methoxyl pectins don't keep well, and if you use last year's box, your jam may not set up properly. This means the storability of Pomona is a big advantage.

Another advantage is the "tweakability" factor. You can make double batches with Pomona, unlike with high methoxyl pectins, and that can be a huge time-saver. You can also add a certain amount of extra ingredients without messing up the pectin's action...just add a little extra lemon juice to keep the acidity factor high. And if your jam turns out too stiff or too runny, you can go back and tweak the jelling action.

All these things, plus the flexibility to use less sugar or different types of sweeteners, makes Pomona the first pectin choice of many experienced cooks. It's definitely a brand to check out if you do much jamming, or if you prefer the taste of fruit over the taste of sugar.

Do keep in mind that if you are using less sugar, there will be less volume in the final product. Also, the lower the sugar, the softer the jam set tends to be, if that makes a difference to you. But most people are more than happy to trade off these issues for the many advantages of Pomona.

Pomona Pectin can be hard to find in regular supermarkets, although most natural food stores carry it. You can also order it directly from Amazon, or you can get it through Pomona's website. Many food co-ops also carry it, and so do many farm-oriented stores.

Because of its many advantages, it's well worth the trouble to find and learn to use this less common type of pectin.

Do You Have to Use Pectin?

I'm sure some people are wondering whether you absolutely need to have pectin in order to make jam. Of course not; people made jam long before commercial pectin was around, But pectin does make your life a bit easier, which is why it's so popular.

Different fruits have differing amounts of pectin in them, so some don't need extra pectin to set up. For example, apples, cranberries, currants, gooseberries, quinces, and citrus fruits have a lot of natural pectin and often don't need anything extra.

Most berries, peaches, and apricots, on the other hand, have very little natural pectin. But even low-pectin fruits can make a decent jam if you cook them long enough, add a lot of sugar, and add a little acid (like lemon juice). The problem is you have to stir them in a hot steamy pot for quite a while, usually in the middle of the hot summer. Boiling for a long time also reduces the amount of nutrients in the fruit and the amount of jam produced.

Thus, many people elect to use pectins as a way to make jamming faster and cooler, and as a way to keep the jam more nutritious and less caloric. Others prefer to make jam without the shortcut of added pectin, feeling that the flavor is richer that way, even if the jam is a little runnier. It's all about your preferences.

You can find instructions for making jam without pectin here. The trick is to use a certain amount of fruit that is a bit underripe (has more natural pectin), but not so much that the flavor is compromised. Another option is to add apple juice instead of water when cooking, or to add other high-pectin fruits to the jam.

If you are going to make jam without pectin, it's important that you know how to recognize when it jells properly, as the amount of cooking time will depend on the ingredients used, the ripeness of the fruit, the water content of the fruit, your elevation, etc.

So the cooking skill-set needed for no-pectin jams is a little higher, but it can absolutely be done.

Can You Make Your Own Pectin?

Some people don't want to use commercial pectin, either because it is cheaper to make your own, or because they object to the processing that commercial pectin goes through.

Commercial pectin is made mostly from citrus peels or apple pomace (what's left over after juicing apples). New pectins are being developed from sugar beets and even sunflowers, but citrus peels (and apple pomace to a lesser extent) are the most common sources for commercial pectin.

If I understand the process correctly, hot dilute acid is added, the results are separated and filtered, and alcohol is used to precipitate out the pectin. The product is washed and dried and made into a powder. This becomes the high methoxyl pectin we see in most supermarket brands.

High-methoxyl pectins (DE usually 60-75%%) are subjected to a de-esterification process using acid in order to hydrolise some of the ester groups and create low methoxyl pectins (DE around 20-40%). For the very low methoxyl pectins like Pomona, hydrolysis using ammonia converts some of the ester groups into amide groups, creating the amidated low methoxyl pectin that is needed for low/no sugar pectins.

All of this sounds complex and off-putting but is generally considered very safe. Still, if you object to all this processing or simply want a cheaper, more easily available pectin, you can make your own pectin at home from underripe apples or crabapples. Directions can be found here, here, or here.

Remember that the result will be a high methoxyl pectin, but one that may result in a less firm gel than commercial pectins. You will need to use a lot of sugar (and some acid) in these recipes, need to have the skill to recognize when the proper jelling stage is reached, and be accepting of a slightly runnier product. But making your own pectin is definitely do-able; it's what most of our great-grandmothers did.

Final Thoughts

Well, there you go, more than you ever wanted to know about pectin!

Turns out, pectin was way more interesting (and way more complex!) than I thought it was going to be when I started. What I thought was correct was often incorrect when I did a little more research. And I found that there are an awful lot of strong opinions out there about pectins.

However, what it boils down to (!) is that there are two main types of pectin. High methoxyl pectins needs lots of sugar and some acidity to jell, and low methoxyl pectins need calcium to jell and are thus great for jams with less sugar.

You can use commercial pectins, make your own, or create a jelling effect by cooking the fruits for a long time, but there is little consensus about the "best" type of pectin. It all depends on what you want out of a pectin, what you are making, what fruit you are using, how sweet you like things, what sweetener you want to use, what gel consistency you want, and your opinions about how pectins are made. The key is to experiment and find out what you prefer.

Some people prefer their jams super-sweet and cooked. If this is you, high methoxyl pectins are probably your best choice. Sure-Jell in the yellow box, Certo or Ball liquid pectin, or Ball regular pectin are all brands that work well for full-sugar jams.

Some people want to use less sugar but don't want an ultra-low sugar jam. Low methoxyl pectins like Sure-Jell in the pink box, Ball's Low or No Sugar Pectin, or Pomona Pectin are the best for this, and they all result in great-tasting jams that are still plenty sweet.

If you want very little sugar in your jam (or prefer a different type of sweetener), then an amidated low methoxyl pectin like Pomona Pectin is the way to go.

Most people I know who do a lot of jamming prefer Pomona, frankly, because it's so much more flexible than the other pectins. It's harder to find, but seems well worth the effort. However, any type of pectin works very well and results in a good product.

You can also make your jams without any added pectin. I would like to try this at some point so I know how to do it, but generally I prefer not to cook jams that long. The flavor is too overcooked for my taste, and the jams too sweet. But many purists prefer this style.

If you are feeling adventurous, make your own pectin! I've never done this either, but I like the DIY aspect of it, and it's a good skill from an emergency preparedness point of view. I will try this at some point so I know how to do it, but it probably won't be my main kind of jamming unless it needs to be.

Personally, I prefer the low methoxyl pectins. I've had great luck with Sure-Jell in the pink box; it was very easy for a beginner to use and the results were really tasty. I'm experimenting now with using Pomona Pectin in order to reduce sugar content even more in my jams. I really like the flexibility it offers over other pectins, so I think I'll probably use it more as I do more canning.

If you are a beginner and feeling totally intimidated about the whole process, I suggest you start with the pink box Sure-Jell Strawberry Freezer Jam recipe so you have an easy first experience with jamming and don't have the added intimidation of water-bath canning. And the flavor of this jam is soooo good, it makes great Christmas gifts...if you can bear to give it away!

Then when you have had your first successes (and have gotten addicted to homemade jam!), try some of the canning recipes that use a boiling water bath. Truly, it's not that hard, and you're not going to poison your family. Plus the results are delicious and don't have to be frozen!

As a fellow beginner, I would also remind you that you don't have to preserve everything under the sun. People often feel intimidated by the Canning Queens out there and can't envision spending that much time and effort. Just because some people spend tons of time on canning doesn't mean you have to. You can preserve food just as much or as little as you prefer.

Start small and see how it feels, then if you like it, expand into different fruits, techniques, and pectins as your time allows. Take a class and learn new techniques if you prefer to learn by watching and doing. Experiment with new recipes. Allow yourself to make mistakes and remember that you don't have to be an expert overnight.

I promise, you don't have to be Betty Crocker or Susie Homemaker to learn how to can. I'm about as far from a Domestic Goddess as you can get, but I've found canning quite rewarding, not to mention delicious and nutritious. Give it a try!

*What are your favorite jam recipes? Tell us about them and share a link to the recipe!

**Pectin Trivia: High methoxyl pectin is also being used as a treatment for some cases of high LDL cholesterol, as it inhibits the absorption of cholesterol from foods. It's a common ingredient in anti-diarrheal meds as well. There is also some evidence that modified citrus pectin (MCP) may reduce the risk of tumor metastasis, especially in prostate cancer and perhaps breast cancer and melanoma. However, all this is preliminary and far from well-proven; always consult your care provider before trying anything new. I just thought it was interesting that pectin might have some medicinal benefits too.

***Update October 2018: I now have added a guide to Remaking Runny Jams. If you have a batch of jam or jelly that does not set up and gel, try some of the techniques in this post.

Further Canning and Pectin Information

General Canning Information

General Pectin Information

Pectin Info for Science Geeks

Info on Making Low-Sugar Jams

Thursday, August 30, 2012

Getting Started with Canning

World War I Canning Poster,
Image from Wikimedia Commons

We are talking about gardening and canning the goodness from our gardens (or the farmer's market). Today we address reasons why some people are reluctant to start learning about canning, and how they can get started if they decide to try it.

Canning Safety

A few years ago, I was scared to death to try canning, just like many other people are. I was afraid I might inadvertently kill my family. But canning's gotten a bad rap over the years, and the science behind canning safety has come a long way. If you follow the directions, you are unlikely to make your family ill. The key is to know a few basic principles and to follow recipes carefully, especially in a few key foods.

Safety-wise, what I didn't know then was that high-acid foods, like the jams and jellies most people start with, aren't really that dangerous. You're not going to get botulism from jams of high-acid fruits. You might get yeast or mold, but you'll see any spoilage, unlike with botulism, which is odorless and colorless.

So with jams, you'll know if your canned food has gone bad and that you should throw it out. (Throw it all out, because mold extends down into foods beyond what you can see, and can produce mycotoxins which might make you sick).

Botulism, the real thing to worry about, mostly occurs with tomatoes or low-acid products like canned vegetables and meat. The problem is that if your salsa, canned asparagus, or canned beef has gotten botulism, you might not know it and botulism is dangerous stuff. Although it's not common, some cases of botulism do occur each year and can be life-threatening.

Jams and preserves are much safer, and that's why they are best for beginners to start with. They are much more forgiving of errors, and spoilage (if any even occurs) will be obvious.

Make no mistake; the other foods can be done safely too, but you need to learn how to do it right (and what prevents botulism). If you want to do tomatoes and/or low-acid foods, get yourself a pressure canner, take a class so you know how to do it safely, and follow tested recipes exactly.

Canning Resources

The other reason people avoid canning is because they think it's really hard. I promise you, canning is not that hard. It just takes a little practice.

I do suggest canning classes if you can manage it, even just for jams. It's really great to learn the science behind canning so you know proper safety practices, so you practice canning skills in a group where you can learn from each other, and so you have an expert to answer common questions. It's also a great way to find new and unusual recipes.

I first learned how to can from a friend of the family, but she follows old outdated practices (no boiling water bath). Many of the jars of jam we processed went moldy. While this wouldn't have killed us, it was an awful waste of food. So I recommend taking a class from trained teachers rather than learning it from a friend or family member, unless you know that person has been properly trained first.

Google your state's name and "extension classes" and many states will have a selection of various canning classes available through the agriculture department of your state university. They are often offered as "outreach" classes in various communities around the state, so you may not have to travel too far. Many larger cities also now offer canning classes through local cooking schools, gardening societies, urban homesteading organizations, and other groups. So there are lots of choices available. And many extension services have a "preserving" hotline in the summer that you can call if you have questions.

I learned how to can from books (after the disaster with my friend). This summer I took extension classes with my daughter to make sure she knows how to can before she graduates high school, and to brush up on my own skills. The classes were great because I learned some things I didn't know. It was very much worth the time and effort and they really didn't take a lot of time.

Being a geek, I especially liked the dollops of science in the class explaining why things worked and why the safety rules were there. I also really liked the hands-on portion of the classes where we put the lessons to work (especially because they did the prep and the clean-up!). And we got to take home several jars of our homemade jelly/jam, pie filling, and salsa. YUM.

However, if there are no classes in your area or you want to get started on your own, the best place to start is Ball's home preserving books. Ball's Blue Book Guide to Preserving is the classic of the field. All the recipes are carefully tested and there are instructions on how to can. I also really like Ball's Complete Book of Home Preserving. Everyone who cans should own these books as references.

If you are the type of person who learns best by watching instead of reading, you can also find many videos on YouTube etc., demonstrating how to do all this. Some of the best are from the Ball website, http://freshpreserving.com/getting-started.aspx.

Personally, my favorite canning book is "Put 'Em Up" by Sherri Brooks Vinton. There are lots of good canning books out there to choose from, but hers has some of the clearest directions and illustrations of the basic canning process I've found, and she has her recipes organized by type of fruit, which makes it easier to use than most books. She also has info on pickling, freezing, and drying, so it's useful on several fronts.

Another good book (and website) is foodinjars.com. If you don't have many people in your house, she has recipes that are suitable for small-batch canning. And her website has tons of ideas and info. I especially like her "it's okay to make mistakes" philosophy.

Generally speaking, you do want to use recipes that have been tested. Again, jams are more forgiving than low-acid foods so there's more room for creativity, but for tomato and low-acid foods you want to be sure to use recipes that have been thoroughly tested for safety, and to follow those recipes exactly.

The best resource for thoroughly tested recipes is Ball's website, freshpreserving.com. LOTS of good recipes there. Or there's Georgia's National Center for Home Food Preservation, http://nchfp.uga.edu/. They have a good book, "So Easy to Preserve," available by mail order, plus lots of online resources too.

Summary

Canning is actually a lot easier than it looks at first. Take it from someone who was scared to death to try it not all that long ago!

Starting with high-acid fruits is the way to go. It's easy, forgiving, and you won't kill your family. And the fresh taste of summer in the middle of winter will motivate you to come back to do more each year!

If time is an issue for you like it is for many of us, remember that you don't have to preserve everything in sight. It's not all-or-nothing. Start with something small, like an easy canned jam. You don't need to be canning all summer long unless you want to. Just do what you have time for. It still counts, even if you don't have the giant shelves of canned goods that some people do. It's okay to start slow and easy, and it's okay to just do what you have time for.

If money is an issue, look on Craigslist or Goodwill for used canning equipment. Or go look in the stores right now; lots of canning equipment is on clearance right now because they want to make room for fall stuff. You can get some great deals that way. But really, you don't need a special pot for canning; just one big enough to handle covering the jars with an inch or two to spare. An old stock pot is just as good. Do get the special jar-lifting tongs, the canning rack, the lid-lifter, a good funnel, and such; that will make your life easier. But that's all you really need if you already own a good stock pot. (Or if you are doing small-batch canning in small jars, you may not even need a stock pot.)

If you still feel uneasy about canning, try making freezer jam instead. (That's what I did.) The Sure-Jell Strawberry Freezer Jam (low-sugar, pink box) is to die for! Or you can make regular jams and then just freeze them instead of canning. The trick is to just get your foot in the door. Eventually you'll get up enough guts to try full-blown canning.

Again, remember that if you want to can vegetables or meats, they have to be done in a pressure canner because they are low-acid foods. (We missed that class this year, so that's a project for next year.) Tomatoes can be done in boiling water bath canners, but only by adding extra acidity with lemon juice or vinegar, and with careful attention to the proportion of acid to non-acid ingredients. In my opinion, tomatoes and low-acid canning are two types of canning where a class is definitely a must.

But for jams, jellies, and preserves, canning is actually pretty easy. It's mostly a matter of being organized, having the right equipment, getting good fruit, having a reliable resource for questions, and having some good recipes. Then just take the plunge! You'll be glad you did.

*What did you can this summer, or what are you hoping to can? If I have time in the next few weeks, I think I might try Ginger Peach Jam, plus my old stand-bys of applesauce and plum chutney. That's probably all I'll have time for, besides the Roasted Goodness Spaghetti Sauce (for the freezer) I'm famous for. How about you?

Monday, August 27, 2012

Garden and Canning Update

Vintage Canning Poster

Let's talk a little about gardening and canning now that we are reaching the height of canning season.

My garden is reaching its peak soon and I am awash with food to preserve. Most we just eat fresh, but some we preserve for later in the year. Yum!

I've already done some berries (strawberry freezer jam, raspberry jelly, and blueberry-lime jam), and cherries (Drunken Cherries, and cherry-amaretto jam), all from my yard. I froze any blueberries and cherries I didn't get around to canning. Then I took a break.

Now peaches have arrived (from a local farmer, though I hope to plant a peach tree this fall), and my plums are juuuuust about ripe. My daughter and I made some peach/blueberry pie filling, and my husband is making noises about peach butter or ginger-peach preserves. Then, plum chutney!

And since the tomatoes are coming in, I'll be doing my special Roasted Goodness Spaghetti Sauce (frozen, not canned, because it's too hard to get the right amount of acidity for safe canning with all the roasted veggies I put in). That's one of our family's favorites.

I also have frozen a lot of pre-chopped carrots and onions for ease of use in stews and soups later in the year. We grew a ton of carrots this year. Some are destined for spaghetti sauce, but many are being blanched and frozen for other stuff this winter.

Have my first eggplant this year; we'll see how that is. We're eating a ton of green beans right now; I may have to freeze some for later. And we harvested a ton of garlic this year! We'll be vampire-free for some time to come, I think.

Our apples are almost ripe, so applesauce season is just around the corner. I have my first Gravensteins this year, so I'm excited about that. Our other apple trees are just starting to bear as well, so I sense a big applesauce season this year! I love homemade applesauce.

However, I'm most excited over getting my first couple of pluots this year! Pluots are a cross between plums and apricots. Apricots don't grow well in my area, so I grow these instead. They are about 75% plum, but with some of the texture and feel of an apricot. Some people feel that pluots are better than plums for fresh eating. With the right type, I would agree!

I planted some pluot trees several years ago, but never got any before now. I have several different types for cross-pollination purposes, but the one that fruited first was Dandy-Dapple pluot. WOW, how delicious! A nice cross between sweet and tart. There are recipes for pluot jam out there, but I don't think many will make it to the jam jar next year. Too good for fresh eating right off the tree!

Anyhow, enough about my garden. Let's talk about canning a bit, because it can help preserve all this wonderful goodness for later in the year when very little is fresh, and because it's a good way to put aside food for emergencies or leaner times. Yet many people are surprisingly reluctant to take up canning. Why is that?

So in the next week or two, let's talk a little bit about canning and freezing. It's another way for people of all sizes to pursue "slow food" and Health At Every Size. And it just tastes good!

*What have you been growing and/or canning this year?

Thursday, August 16, 2012

Lowering the Risk for Surgical Site Infections in Fat Folk

Image from Chopra 2010 study, link below

We've discussed prevention of surgical site infections before, often in the context of cesareans, but most recently in the context of Emergency Room visits.

Regardless of type of operation, however, accumulating evidence suggests that antibiotic regimens for "obese" people need to be adjusted.

We in the Size Acceptance Movement have been saying for years that people of size often benefit from larger or weight-based dosing for certain types of antibiotics, longer courses of antibiotics in some cases, and IV antibiotics instead of oral antibiotics for serious infections.

This was based on the anecdotal experiences of many people of size over the years, and as such, was summarily dismissed by many in the medical community.

Here is research that confirms the importance of longer courses of antibiotics and weight-based dosing, and which also suggests that more frequent dosing, administration of antibiotics by IV, and perhaps topical infusion of antibiotics into the wound itself before closing (instead of just systemically in the IV) seem to improve outcomes.

Of course, different types of antibiotics work differently in the system. This means that some types of antibiotics need different dosing for obese people and some don't. That's important to remember ─ the need for weight-based dosing is not universal for all drugs. And to be fair to doctors, research has been slow to differentiate these and to provide easy-to-use guidance to doctors in their prescriptions.

Yet there is some research that addresses this issue now, but as we saw recently in the Emergency Room study, getting doctors to follow this research is difficult. In that study, simple guidelines for dosing for high-BMI patients in the E.R. were readily available, but even so, less than 5% of morbidly obese patients received the proper initial dosage of common antibiotics. And that was at a medical center that specialized in treating obese patients!

Furthermore, another study has shown that hospital pharmacists often do not catch/correct underdosing errors in high-BMI patients. In that study, less than 1/3 of obese patients received an adequate initial dose of vancomycin, only 1% received the optimum recommended dose, and only about 3% of these underdosing cases were caught and corrected by hospital pharmacists.

Far too often, people of size are still being treated with standard antibiotic dosages instead of dosages tailored to their weight, or antibiotics given too infrequently, orally, or for an insufficient length of time.

When will doctors listen to people of size and learn from our experiences? Heck, when will they learn from their own research?

What is the barrier to adopting these new regimens? Why aren't they being utilized far more often? Why aren't hospital pharmacists or medical supervisors catching more inadequate dosing and raising red flags about it?

It's frustrating that this topic is only now being researched and that many hospitals ─ even those that specialize in treating obese patients ─ have been slow to utilize the new dosing guidelines that do exist.

As people of size, we need to be our own best advocates, both before surgery and when surgical site infections occur, so don't be afraid to bring up this concern with your surgeon, or to ask for a consult with an infectious specialist. Even with a specialist, you may have to be ready to assertively argue your case, but they are more likely to be responsive to advocacy if you can cite research like the studies below.

Providers, please press hard for more research on the most optimal antibiotic dose and regimens, and press vigorously for more caregiver education about and usage of these regimens. If there is any question about optimal dosage, please take the time to research the issue, and don't be afraid to explore using a different timing or delivery system. It could literally be the difference between life and death for some people of size.

Infections can be a significant problem in high-BMI patients. Part of this is because of physiological differences like decreased vascular perfusion in fat tissue, and thus decreased oxygenation. But an under-recognized part of it is because clinicians are using the wrong dosages and treatment regimens for fat folk.

The most efficient approach to improving outcome in obese patients is still to prevent infection in the first place by using the most effective antibiotic dose and treatment protocols available for our unique needs.

References

Am J Obstet Gynecol. 2010 Mar;202(3):306.e1-9. Extended antibiotic prophylaxis for prevention of surgical-site infections in morbidly obese women who undergo combined hysterectomy and medically indicated panniculectomy: a cohort study. El-Nashar SA, et al. PMID: 20207249

OBJECTIVE: The purpose of this study was to compare surgical-site infection rates in obese women who had extended prophylactic antibiotic (EPA) vs standard prophylactic antibiotic.
STUDY DESIGN: An electronic records-linkage system identified 145 obese women (body mass index, >30 kg/m(2)) who underwent combined hysterectomy and panniculectomy from January 1, 2005, through December 31, 2008. The EPA cohort received standard antibiotics (cefazolin, 2 g) and continued oral antibiotic (ciprofloxacin) until removal of drains. Regression models were used to adjust for known confounders. RESULTS:The mean age was 56.0 + or - 12.1 years, and mean body mass index was 42.6 + or - 8.4 kg/m(2) (range, 30-86.4 kg/m(2)). The EPA cohort experienced fewer surgical-site infections (6 [5.9%] vs 12 [27.9%]; P less than .001; adjusted odds ratio, 0.16; 95% confidence interval, 0.04-0.51; P less than .001), had lower probability of incision and drainage (3 [2.9%] vs 5 [11.6%]; P = .05), and required fewer infection-related admissions (5 [4.9%] vs 6 [13.9%]; P = .08). CONCLUSION: Extended antibiotic prophylaxis can reduce surgical-site infections in obese women after combined hysterectomy and panniculectomy.

Surg Infect (Larchmt). 2009 Feb;10(1):53-7. Prevention of surgical site infections by an infusion of topical antibiotics in morbidly obese patients. Alexander JW, Rahn R, Goodman HR. PMID: 19245364

BACKGROUND: The reported incidence of surgical site infection after abdominal surgery in morbidly obese patients is high (about 15% in most studies), and this is associated with considerable disability and an increased economic burden. Topical antibiotics may reduce the incidence of serious infections. METHODS: Standard techniques for the prevention of surgical site infections were used along with the introduction of kanamycin into the subcutaneous space of morbidly obese patients at the time of closure and allowing it to dwell for 2 h. Eight hundred thirty-seven evaluable patients were followed for the development of site complications for at least six weeks postoperatively. RESULTS: One of the 65 patients with a revisional procedure had a primary deep incisional surgical site infection, as did one of the 772 patients with a primary operation. Secondary deep incisional surgical site infections occurred in four patients, two after spontaneous evacuation of a seroma, one from excessive superficial contamination, and one following separation of a nonhealing surgical site. Additionally, 21 patients had minor surgical site complications including incisional separation and stitch-related infections, which required no significant expenditure of resources. CONCLUSIONS: Prolonged contact (2 h) of topical kanamycin solution with the surgical site greatly reduces the incidence of primary infections in the deep subcutaneous space of laparotomy sites in morbidly obese patients.

Expert Rev Pharmacoecon Outcomes Res. 2010 Jun;10(3):317-28. Preventing surgical site infections after bariatric surgery: value of perioperative antibiotic regimens. Chopra T, et al. PMID: 20545596 Full free text available here.

Kmom Summary: This paper reviews the surgical site infections (SSIs) that occur post bariatric surgery, and how to prevent SSIs. "This paper sets out to define different types of SSIs that occur following bariatric surgery and to discuss existing literature on the critical aspects of SSI prevention and the appropriate use of surgical antimicrobial prophylaxis for bariatric surgery."

Important quote: "Most antimicrobial agents do not achieve optimal serum levels when administered orally. Although certain oral antimicrobials have comparable bioavailability with their intravenous formulation, the time to achieve maximum serum concentration is slower due to the need for absorption through the gastrointestinal tract. Intravenous antimicrobial prophylaxis is the most extensively studied route and remains the preferred route of administration."

Obes Surg. 2012 Mar;22(3):465-71. Cefepime dosing in the morbidly obese patient population. Rich BS, et al. PMID: 22249886

Proper dosing of specific antibiotics in morbidly obese patients has been studied inadequately. However, these data are beneficial as this patient population is at an increased risk to develop postoperative infections. Cefepime is an antibiotic used for the treatment of both gram-positive and especially gram-negative infections; administration of the appropriate dose in the morbidly obese population is crucial. We therefore examined the pharmacokinetics of cefepime in patients with body mass index >40 kg/m(2). Ten morbidly obese patients, with a mean [±SD] estimated glomerular filtration rate of 108.4 ± 34.6 mL/min, undergoing elective weight loss surgical procedures were administered cefepime in addition to standard prophylactic cefazolin and studied. Serial serum cefepime concentrations were analyzed after dosing using a validated high performance liquid chromatography method. Pharmacokinetics and duration above the minimum inhibitory concentration (MIC) were determined using a protein binding value of 15% and a MIC threshold of 8 μg/mL. Mean free cefepime concentrations for t = 30, 120, and 360 min were 69.6, 31.6, and 9.2 μg/mL, respectively. The dosing interval was calculated to maintain the free concentration above the MIC (fT > MIC) for 60% of the interval. This was determined to be 10.12 h, including time for infusion. There was no toxicity. Based on this analysis, an increased dose of 2 g every 8 h is necessary to maintain an adequate fT > MIC throughout the dosing interval. Further studies are necessary to determine the efficacy of this regimen in the settings of active infections and critical illness.

Pharmacotherapy. 2007 Aug;27(8):1081-91. Antimicrobial dosing considerations in obese adult patients. Pai MP, Bearden DT. PMID: 17655508

As obesity continues to increase in prevalence throughout the world, it becomes important to explore the effects that obesity has on antimicrobial disposition. Physiologic changes in obesity can alter both the volume of distribution and clearance of many commonly used antimicrobials. These changes often present challenges such as estimation of creatinine clearance to predict drug clearance.

Although these physiologic changes are increasingly being characterized, few studies assessing alterations in tissue drug distribution and the effects of obesity on antimicrobial pharmacokinetics have been published. The available data are most plentiful for antibiotics that historically have included clinical therapeutic drug monitoring.

These data suggest that dosing of vancomycin and aminoglycosides be based on total body weight and adjusted body weight, respectively. Obese patients may require larger doses of beta-lactams to achieve similar concentrations as those of patients who are not obese. Fluoroquinolone pharmacokinetics are variably altered by obesity, which prevents a uniform approach. Data on the pharmacokinetics of drugs that have activity against gram-positive organisms-quinupristin-dalfopristin,linezolid, and daptomycin-reveal that they are altered in the presence of obesity, but more data are needed to solidify dosing recommendations. Limited data are available on nonantibacterials.

An understanding of the physiologic changes in obesity and the available literature on specific antibiotics is valuable in providing a framework for rational selection of dosages in this increasingly common population of obese patients.

Am J Med. 2008 Jun;121(6):515-8. Multicenter evaluation of vancomycin dosing: emphasis on obesity. Hall RG 2nd, Payne KD, Bain AM, Rahman AP, Nguyen ST, Eaton SA, Busti AJ, Vu SL, Bedimo R. PMID: 18501233 Full text available here.

BACKGROUND: There is a paucity of data available regarding the dosing of antimicrobials in obesity. However, data are available demonstrating that vancomycin should be dosed on the basis of actual body weight. METHODS: This study was conducted at 2 tertiary care medical centers that did not have pharmacy-guided vancomycin dosing programs or other institutional vancomycin dosing policies or protocols. Patients who received vancomycin between July 1, 2003, and June 30, 2006, were stratified by body mass index and randomly selected from the computer-generated queries. Patients greater or equal to 18 years of age with a creatinine clearance of at least 60 mL/min who received vancomycin for at least 36 hours were included. RESULTS: Data were collected on a random sampling of 421 patients, stratified by body mass index, who met the inclusion criteria. Most patients in each body mass index category received a fixed dose of vancomycin 2 g daily divided into 2 doses (underweight 82%, normal weight 90%, overweight 86%, and obese 91%).

Adequate initial dosing (greater than or=10 mg/kg/dose) was achieved for 100% of underweight, 99% of normal weight, 93.9% of overweight, and 27.7% of obese patients (P less than .0001).

Ninety-seven percent of underweight, 46% of normal weight, 1% of overweight, and 0.6% of obese patients received greater than or =15 mg/kg/dose recommended by several Infectious Diseases Society of America guidelines.

Pharmacists also failed to correct inadequate dosing because only 3.3% of patients receiving less than 10 mg/kg/dose had their regimen changed in the first 24 hours of therapy.

CONCLUSION: In this multicenter pilot study, obese patients routinely received inadequate empiric vancomycin using a lenient assessment of dosing. Greater efforts should be undertaken to ensure patients receive weight-based dosing because inadequate dosing can lead to subtherapeutic concentrations and potentially worse clinical outcomes.

Eur J Clin Pharmacol. 1998 Oct;54(8):621-5. Vancomycin dosing in morbidly obese patients. Bauer LA, Black DJ, Lill JS. PMID: 9860149

OBJECTIVES AND METHODS: Vancomycin hydrochloride dosing requirements in morbidly obese patients with normal renal function were computed to determine the dose of vancomycin necessary to achieve target steady-state peak and trough concentrations and compared with a normal weight population. RESULTS: Morbidly obese patients [total body weight (TBW) 165 kg, ideal body weight (IBW) 63 kg] required 31.2 mg x kg(-1) x d(-1) TBW or 81.9 mg x kg(-1) x d(-1) IBW to achieve the target concentrations. Normal weight patients (TBW 68.6 kg) required 27.8 mg x kg(-1) x d(-1) to achieve the same concentrations. Because of altered kinetic parameters in the morbidly obese patients (obese: t1/2 = 3.3 h, V = 52 L, CL = 197 ml x min(-1); normal: t1/2=7.2 h, V=46 L, CL=77 ml x min(-1), 20 of 24 patients required q8h dosing (1938 mg q8h) compared with q12h dosing (954 mg q12h) in all normal weight patients in order to avoid trough concentrations that were too low for prolonged periods. There was a good correlation between TBW and CL, but only fair correlation between TBW and V. CONCLUSION: Doses required to achieve desired vancomycin concentrations are similar in morbidly obese and normal weight patients when TBW is used as a dosing weight for the obese (approximately 30 mg x kg(-1) x d(-1)). Shorter dosage intervals may be needed when dosing morbidly obese patients so that steady-state trough concentrations remain above 5 microg x ml(-1) in this population. Because of the large amount of variation in required doses, vancomycin serum concentrations should be obtained in morbidly obese patients to ensure that adequate doses are being administered. Dosage requirements for morbidly obese patients with renal dysfunction require further study.

Surgery. 2004 Oct;136(4):738-47. Perioperative antibiotic prophylaxis in the gastric bypass patient: do we achieve therapeutic levels? Edmiston CE, et al. PMID: 15467657

BACKGROUND: Perioperative surgical antibiotic prophylaxis requires that therapeutically effective drug concentrations be present in the tissues. METHODS: Patients undergoing Roux-en-Y gastric bypass for morbid obesity were given 2 g cefazolin preoperatively, followed by a second dose at 3 hours. Thirty-eight patients were each assigned to 1 of 3 body mass index (BMI) groups: (A) BMI=40-49 (N = 17); (B) BMI=50-59 (N=11); (C) BMI > or= 60 (N=10). Multiple timed serum (baseline; incision, 15, 30, 60 minutes; prior to second prophylactic dose; and closure) and tissue (skin, subcutaneous fat, and omentum) specimens were collected and cefazolin concentration analyzed by microbiological assay. RESULTS: No significant difference was observed in intraoperative fluid replacement or blood loss among BMI groups. Serum antimicrobial concentrations exceeded resistance breakpoint (32 microg/mL) in 73%, 68%, and 52% of BMI groups A, B, and C, respectively. No significant difference in cefazolin concentration was observed in mean incisional skin and closure tissue specimens in groups A, B, and C. A significant decrease in cefazolin concentration was noted in closure adipose (p=.04), initial (p=.03) and closure omentum (p=.05) tissues in groups B and C compared with A. Over 90% of serum samples exhibited therapeutic concentrations covering 53.8% of gram-positive and 78.6% of gram-negative surgical pathogens. However, therapeutic tissue levels were achieved in only 48.1%, 28.6%, and 10.2% of groups A, B, and C, respectively. CONCLUSIONS: Pharmacokinetic analysis suggests that present dosing strategies may fail to provide adequate perioperative prophylaxis in gastric bypass patients.

Am J Emerg Med. 2011 Dec 12. Underdosing of common antibiotics for obese patients in the ED. Roe JL, Fuentes JM, Mullins ME. PMID: 22169576

BACKGROUND: Obesity is a growing problem in the United States. Obesity alters the pharmacokinetic profiles of various drugs. Although there are guidelines for dose adjustments for many of the antibiotics commonly used in the emergency department (ED), they are seldom used. METHODS: This is an institutional review board-approved retrospective study at an American Society of Metabolic and Bariatric Surgery Center of Excellence and a level I trauma center with annual ED volumes of more than 80 000 visits. Data were retrospectively collected from ED pharmacy records during a 3-month period in 2008. Any first dose of cefepime, cefazolin, or ciprofloxacin administered in our ED to a patient recorded as both more than 100 kg and with a body mass index greater than 40 kg/m(2) was compared with our hospital guidelines and found to either adhere or not adhere to those guidelines. RESULTS: There were 1910 orders found to meet the study criteria: 775 orders for cefepime, 625 orders for cefazolin, and 510 orders for ciprofloxacin. Adherence rates for first dose of cefepime, cefazolin, and ciprofloxacin administered, respectively, were 8.0%, 3.0%, and 1.2%. CONCLUSION: Emergency physicians frequently underdose cefepime, cefazolin, and ciprofloxacin in obese patients. Underdosing antimicrobials presents risk of treatment failure and may promote antimicrobial resistance. Education is necessary to improve early antibiotic administration to obese patients.

Tuesday, August 7, 2012

Obese Patients Undertreated for Infection in the Emergency Room

The following study shows just how badly obese patients are underdosed with antibiotics in the Emergency Room (E.R.).

Terri of the FattiesUnited blog brought this study to the attention of the fatosphere briefly several months ago, just as I was about to write a post about this study too, so I put the post on the back burner.

However, in writing an upcoming post on treating Surgical Site Infections in people of size, I came across the study again and decided it was important enough to be highlighted once more. Any of us can end in the Emergency Room at any time, regardless of size. But those of us who are fat need to be aware of the possibility of underdosing and to be able to advocate for ourselves as needed. Perhaps sharing the full details of this study will help in that process.

In this study, the initial antibiotic dosages of "morbidly obese" folks (BMI over 40) who visited the E.R. and were prescribed 3 common antibiotics were analyzed retrospectively for a 3-month period. The doses were compared with internal hospital guidelines for antibiotic dose adjustments for obese folks.

Less than 5% of morbidly obese patients were given the correct antibiotic dose for their weight.

That's right, more than 95% of high BMI patients were underdosed with antibiotics, putting them at significant risk for serious complications.

The study notes:

Although there are guidelines for dose adjustments for many of the antibiotics commonly used in the emergency department (ED), they are seldom used...Underdosing antimicrobials presents risk of treatment failure and may promote antimicrobial resistance. Education is necessary to improve early antibiotic administration to obese patients.

Study Details

This study was done as a quality improvement review at an urban Level I trauma center with an emergency medicine residency.

In the study, pharmacy records were collected retrospectively to identify the initial dose of cefazolin, cefepime, or ciproflaxin given in the E.R. to patients with a BMI greater than 40 and who weighed more than 100 kg.

These three drugs were chosen because they are used so frequently and because, unlike many antibiotics, there are readily-available guidelines for dosing obese folks without having to do a bunch of complicated extra calculations first. The guidelines are distributed in a handbook each year to every resident and are also always available on the hospital's internal website, so there was no excuse for not knowing or not checking the recommended dosages.

The study looked at only the initial dose given (and to be fair, any additional dose within 4 hours, as sometimes doctors self-correct dosing when they have a chance to look up the guidelines).

This attention to the initial dose is important because the first dose of antibiotics is the most important in knocking down an infection. According to the study, the effectiveness of this class of antibiotics (cephalosporins) is proportional to the amount of time kept above the Minimum Inhibitory Concentration (MIC). If the initial dose does not achieve MIC, then the patient may develop resistance to the antibiotics, not to mention serious complications, longer hospital stays, or even death.

In the study, there were 1,910 orders that fit the criteria in the 3-month study period. Of these, only 4.6% of the antibiotic orders were dosed appropriately for morbidly obese patients.

For cefepime, the adherence rate was 8%. For cefazolin, the adherence rate was 3%, and for ciproflaxin the adherence rate was only 1.2%.

This is an appallingly poor adherence rate to readily-available, simple dosing guidelines. The study notes this and emphasizes how important it is to ensure adequate dosing in morbidly obese patients:

Attaining therapeutic dosing in [morbidly obese] patients is especially important. Obese patients present a greater risk of infection and a higher morbidity and mortality associated with infection than does the general population. Subtherapeutic dosing increases the risk of treatment failure, unnecessary escalation to broader-spectrum antibiotics, and selection of resistant pathogens...Because early antibiotic administration reduces mortality in life-threatening infections, meeting proper dosing guidelines in the [Emergency Department] should be of the highest priority.

The authors go on to cite another study which found that when the perioperative dose of cefazolin was doubled to 2g in obese patients, the postoperative infection rate dropped from 16.5% to 5.6%. This shows that increased dosages of this antibiotic in heavier patients do result in improved outcomes.

Interestingly, there is recent data (Pevzner 2011) on cesareans in morbidly obese patients suggesting that even a doubled, 2g dose of cefazolin may not be enough, and that further research is needed to figure out the most effective perioperative dose in this group. What implications this has for E.R. usage is unknown but suggests doses bigger than 2g may also need to be considered. Research needs to be done to find the optimal dose for each size.

Concluding Thoughts

Sooner or later, people of every size end up in the E.R., especially as they age. Different populations present different care challenges; obese people present a unique subset whose care challenges are often under-recognized and under-addressed.

Bottom line, the best care protocols for obese people are yet to be determined because research on the topic has been woefully inadequate. Furthermore, even when the best care protocols are known, they are often not followed by medical personnel. Therefore, it is critical as people of size that we know about key care issues in our own care and how to advocate for ourselves when we interact with medical personnel.

One of the most understudied areas in the care of obese patients is optimal medication dosage. Research shows that obese patients (and especially morbidly obese patients) are often dosed inappropriately with a variety of drugs, from chemotherapy to anti-coagulants to antibiotics, and this may be correlated to poorer outcomes among these groups.

Clearly, it is imperative that more research and physician education be done on appropriate medication dosage for people of size as quickly as possible.

In this study, only initial antibiotic dosing at the Emergency Room was examined, using only common antibiotics with easily-available dose adjustments. Even so, less than 5% of the morbidly obese patients were given dosages that adhered to the internal guidelines of the hospital.

One has to wonder how adequate the dosing was in very fat patients for the rest of their hospital stays and how that impacted their outcomes.

Ironically, this was in a hospital that is a regional referral center for fat patients and is recognized as a Bariatric Surgery "Center of Excellence" (ugh). That makes the findings even more alarming.

If a teaching hospital that specializes in the treatment of very fat people doesn't routinely use the correct antibiotic dosing in their E.R., what are the underdosing rates in community hospitals that don't specialize in fat patients at all?

This study has lessons both for people of size and for the medical community.

Fat people should know that if they end up in the E.R. for an infection of some sort, they need to ask their physician to check into adjusted antibiotic doses for weight. Not every type of antibiotic needs dose adjustment, mind ─ it all depends on how they are designed to work in the body. But this study indicates that you may really have to push your physician to find out about dose adjustments and to use them when they are indicated.

Most physicians truly want their patients to get better, so it's really OK to ask about whether weight-based dosing is needed for you. However, don't be afraid to ask for a consult with an infections specialist if you feel your E.R. doctor is not attentive to your concerns, or to involve the hospital's Patient Advocate in getting your concerns heard. There are measures in place to help patients advocate for their own needs, and you don't have to go it alone.

But the first step is self-education, to know where the potential issues may lie, to know to ask questions about dosages, and to feel empowered enough to do so.

For medical professionals, the associated lesson is that they must aggressively press for better research on optimal medication dosage in obese patients, and to continue to push for more physician education and accountability on these matters.

*Next post.....other ways to improve response to infections in people of size, including IV antibiotics, more frequent dosings, and topical infusions.

References

Am J Emerg Med. 2011 Dec 12. Underdosing of common antibiotics for obese patients in the ED. Roe JL, Fuentes JM, Mullins ME. PMID: 22169576

BACKGROUND: Obesity is a growing problem in the United States. Obesity alters the pharmacokinetic profiles of various drugs. Although there are guidelines for dose adjustments for many of the antibiotics commonly used in the emergency department (ED), they are seldom used. METHODS: This is an institutional review board-approved retrospective study at an American Society of Metabolic and Bariatric Surgery Center of Excellence and a level I trauma center with annual ED volumes of more than 80 000 visits. Data were retrospectively collected from ED pharmacy records during a 3-month period in 2008. Any first dose of cefepime, cefazolin, or ciprofloxacin administered in our ED to a patient recorded as both more than 100 kg and with a body mass index greater than 40 kg/m(2) was compared with our hospital guidelines and found to either adhere or not adhere to those guidelines. RESULTS: There were 1910 orders found to meet the study criteria: 775 orders for cefepime, 625 orders for cefazolin, and 510 orders for ciprofloxacin. Adherence rates for first dose of cefepime, cefazolin, and ciprofloxacin administered, respectively, were 8.0%, 3.0%, and 1.2%. CONCLUSION: Emergency physicians frequently underdose cefepime, cefazolin, and ciprofloxacin in obese patients. Underdosing antimicrobials presents risk of treatment failure and may promote antimicrobial resistance. Education is necessary to improve early antibiotic administration to obese patients.