Just Because Something Sounds True Doesn't Mean It Is

I have been thinking a lot about how easily medical misunderstandings happen and how easily misinformation can be propagated. Specifically, I have heard concerns from some patients that the commonly-used laxative, Miralax, contains antifreeze. Fortunately this is not the case. I helped take care of a child who had ingested antifreeze during my time in the Pediatric Intensive Care Unit as a resident at UVa. That is not something we would want any child to go through.

The confusion comes from the similar-sounding ingredients. The main ingredient in Miralax is polyethylene glycol and many brands of antifreeze contain ethylene glycol. It sure sounds like they are almost the same thing and would probably have the same effects, right? But they aren’t and they don’t.

Consider this. Regular table salt is sodium chloride. It tastes good and we need a certain amount of it to maintain proper electrolyte levels in our bodies. Using too much can increase blood pressure but we all use it and it is not acutely dangerous. One may then think that plain old sodium would react similarly, but it doesn’t. When placed in water, pure sodium reacts violently, bursting into flames. Obviously that would cause a very concerning reaction if it was on your French fries.

So even though the names are similar and both contain sodium, sodium chloride and sodium metal are completely different chemicals with completely different properties and effects. The same is true of polyethylene glycol and ethylene glycol.

So just because two things sound similar and it sounds true that they are the same, that is often not the case. Come to think of it, that applies to a lot more in life than just medicine and chemistry.

The Importance of Strep Tests

One of the most common reasons for patients to come see us is for a sore throat. Except in extremely unusual circumstances, the only bacterial cause of throat infections in children is strep throat. That means that strep throat is the only cause of a sore throat which will be helped by treatment with antibiotics. Furthermore, strep is less common than viruses as a cause of sore throats.

There is a quick, easy test to check for strep throat that involves swabbing the throat and testing for streptococcal antigens (essentially tiny pieces of the strep bacteria). These tests catch a very high percentage of cases of strep throat. If the strep test is negative, generally a back-up throat culture is performed to pick up the ones that sneak through unidentified.

Why is this important? Because doctors are not very good at diagnosing strep throat without the test. When I was in the first year of my pediatric residency at UVa, we had a contest to see who could best predict the results of strep tests on their patients. We wrote down our predictions prior to having the tests run and then calculated who had the highest percentage correct for the year. I was the “Golden Loop” winner for my year (named for the loop used to streak a sample on a blood agar plate for growing bacteria). Even so, I think my percentage of correct predictions was only around 70%. And after 18 years of practicing pediatrics and thousands of visits in which I have done strep tests, it is still not unusual for me to be surprised by the result of a strep test.

Some providers diagnose strep throat using the Centor criteria. These criteria were developed for adults. If a patient meets all of the criteria, their chance of having strep throat is around 50%. So if adults are treated based on these criteria alone, about half of them will receive antibiotics for a condition which they do not have. When applied to children, the predictive value of these criteria is even lower.

It is not unusual for us to see patients who were seen elsewhere for a sore throat, placed on antibiotics without a strep test, and are no better a couple days later. It is understandably frustrating for them to have a second visit for the same problem only to learn they have an illness for which the treatment they were prescribed would not be expected to be helpful.

Strep tests are quick, easy, and reliable. So the next time someone wants to treat your child’s sore throat with antibiotics without first testing for strep, request a strep test. There is a good chance it could save him from taking 10 days of antibiotics which will not help and could cause side effects. In addition, you will be doing society a favor. Overuse of antibiotics leads to antibiotic resistance and, according to one recent estimate, infections with antibiotic-resistant bacteria cost the United States $20 billion annually. The first, obvious step to combating antibiotic resistance and doing what’s best for patients, is to not use antibiotics for conditions they will not help.

How We Know What Works

One of the pillars upon which modern medicine is based is objectively determining if a certain procedure, treatment, etc. is the cause of a certain outcome.

For example, when the meningococcal conjugate vaccine was first introduced, there were reports of Guillain-Barre syndrome (a rare, temporary paralysis) in a few persons who had received the vaccine and some concern that the vaccine may have caused it. It turned out that when the data was analyzed, it was found that people who had received the vaccine were no more likely to get GBS than those who had not received the vaccine. So the few cases of GBS after vaccination were a coincidence. This concept is often summed up with the saying “Correlation is not causation,” meaning that just because two things have a temporal relationship doesn’t mean one caused the other. Now years later, we know that the vaccine does not cause GBS and we have been able to protect a multitude of young people against deadly meningococcal disease with the vaccine.

Similarly, it is important to have control groups to see if treatments work. If 80% of people taking Treatment A get better, it must work, right? What if 80% of people with the same disease who did not get Treatment A (the control group) also get better? Suddenly Treatment A doesn’t look so great.

In medical trials, treatments are usually compared to a placebo. A placebo is something that is made to look, taste, etc. like the treatment in question but has no medication in it (ie. a “sugar pill”). In an ideal trial, the patients and doctors do not know who is receiving a placebo and who is receiving the treatment being investigated. Then the results are compared to see if the treatment in question worked any better than the placebo.

This approach is what allows us to provide treatments that provide benefits to patients and avoid treatments that don’t work or may even be harmful. Stories of individuals’ experiences can guide further investigation, but it is often only when the experiences of many individuals are compiled in a systematic way which minimizes bias as much as possible that one can separate the wheat from the chaff.

 

Children and Second-Hand Tobacco Smoke

There are many reasons to avoid exposing children to second-hand tobacco smoke. We know that second-hand smoke exposure increases the risk of Sudden Infant Death Syndrome, respiratory problems, and learning and behavior problems.

A new study in the August issue of The Journal of Pediatrics suggests that exposure to tobacco smoke may also impair motor development in children. Children aged 7-9 had urine cotinine levels measured as a marker for exposure to second-hand smoke. Findings were adjusted to account for other factors known to affect motor development. The children with cotinine in their urine were more likely to have impairment in a variety of motor abilities including coordination, balance, and strength when compared to children who did not have cotinine in their urine.

A second study in the same issue of J Peds found similar impairments in motor development if children were exposed to tobacco prenatally through maternal smoking during pregnancy. When we think of tobacco smoke, we usually think about its effects on the respiratory system but it is clear that it also has effects on a child’s developing nervous system.

We would hope that no children would be exposed to second-hand smoke but we also recognize that it is very difficult for parents and family members to stop smoking. Keeping smoke as far away from children as possible is good but we also know that children whose family members smoke outside, away from them, will also get some exposure. Ultimately, stopping smoking is best for the smoker and everyone around him. It is possible to stop and I have had the opportunity to celebrate along with the parents of some of my patients when they have been able to quit.

For those who are interested in stopping, I would encourage you to talk with your own physician about options which may make it easier, for your own health and the health of those around you.

The Decline of Pneumococcal Infections

Early in my career as a pediatrician, I would sometimes lie awake at night worrying about pneumococcus. Pneumococcus is a type of strep bacteria (different than the one that causes strep throat) which can cause serious infections such as meningitis, bloodstream infections, and pneumonia. Unfortunately, early in the course of an invasive pneumococcal infection, the symptoms can be the same as in a plethora of common, self-limited, viral infections, especially in young children.

This is what resulted in sleepless nights, wondering if I could have missed something serious hidden among the multitude of benign illnesses. As a result, we would obtain labs on some children with fevers who met certain criteria or even admit them to the hospital for observation or give them injections of antibiotics until we had final blood culture results available, usually in 48 hours. Most of those children did not end up having serious illnesses but, depending on the situation, waiting to see could have resulted in what are sometimes referred to euphemistically as “bad outcomes.”

The first pneumococcal conjugate vaccine was introduced in 2000 and there was a 76% decrease in invasive pneumococcal infections over the next seven years. In 2010, a new version of the vaccine containing more serotypes of pneumococcal antigens was released. A new study in JAMA Pediatrics reports a further 70% decrease in invasive pneumococcal disease in a population of children in New York City monitored since the introduction of the new vaccine.

I can’t remember the last time I saw an invasive pneumococcal infection. I sleep much better than I used to. And most importantly, children and their families are at much lower risk of these serious infections than they used to be.

The End of an Era

I will eventually get to medical topics on this blog but wanted to first pay tribute to a friend and colleague.

Dr. George T. Sproul has retired after 38 years of practicing pediatrics in Staunton. I had the pleasure of working with him for the last 18 of those years. During those years, he was first my physician manager, then my business partner, and finally an employed physician the past few years. In all of those roles I always found him to be a man of integrity. He is kind, honest, hard-working, and always did what he thought was best for patients.

He is a lover of nature as exhibited by the bird feeders that have always been around our offices, first on Commerce Road in Staunton and now in Verona. I have learned a lot about medicine from him through the years but he has also been a frequent recipient of my questions regarding local nature and history, astronomy, and science in general.

I recently have heard that some families refer to him as “The Baby Whisperer” for his calming manner when dealing with patients. At the old office, he could frequently be seen taking patients over to the edge of the parking lot towards the stream to show them what poison ivy plants look like. Over the past few months, as his retirement neared, I enjoyed hearing grandmothers of patients reminisce about bringing their children to see him and mothers of patients talk about when they used to be his patients.

I know pediatrics has changed a lot in the past 18 years so I can’t quite imagine how different things must have been 38 years ago. But doing our best to care for patients is one thing that should never change. Dr. Sproul’s legacy of compassion for patients combined with intellectual integrity is one I aspire to continue. His presence will be greatly missed.

Old Newspaper Column, New Blog

I formerly wrote a monthly column on pediatrics for the local newspaper. Writing is one of my hobbies and I found it enjoyable and I believe it was at least somewhat informative as well. Then life got crazy with family activities, frequent call nights running to the hospital, and all sorts of other things and it kind of fell by the wayside.

But I recently realized that I missed writing my column and have had enough people ask me about it to think that it must have been at least somewhat helpful. So I have decided to resurrect it as a blog (it is 2015, after all).

My intent is to cover topics related to the health and well-being of children and adolescents and their families based on published data as well as my experience as a practicing pediatrician and father. As with everything else in life, it seems that the more I learn and experience in medicine, the more I realize I do not know. So I tend to hold my thoughts and opinions a bit more loosely than at times in the past and I think this is a good thing. But I also think there are some things that I have learned that I hope you find interesting and useful.