On Call and Evidence Based Medicine

Calling Dr. MacDonald…..

When I am ‘on-call’ for my sports medicine clinic practice I receive a mixed bag of phone calls.  The calls come in from patients we take care of, to emergency physicians looking for help triaging patients, to community physicians looking for consultation. Because I do non-operative, primary care sports medicine, I’m rarely involved in an emergency when ‘on-call’; any urgent or emergent issue I need to manage typically occurs when I am on a sideline and not nominally ‘on-call.’

Last week, I received an interesting query about muscle pain in a high school runner who had been doing some intense pre-season training.  The physician seeking my advice had felt obliged to check the patient’s creatine kinase (CK) and told me the level was 1400 U/L.  He had already obtained a urine for myoglobinuria (negative), and he was asking if he should be clearing the patient to return to sport.

Most of my clinical work involves taking care of fractures or concussions, spondylolysis or osteochondritis dissecans.  As with a lot of clinicians, I suspect, for the conditions I treat in high volume I have the facts usually at the tip of my tongue.  Though I have manged the condition, I don’t routinely treat patients where rhabdomyolysis is in the differential.  And so, with this specific phone consultation, I assured the physician the patient was in no imminent danger, but I wanted to get back to him later that day after I had done a literature search.

Though I did not think about this explicitly at the time, I later realized that this little vignette represents an example of “Evidence Based Medicine” (EBM) in use.  As Sackett et al. state in 1996, “Evidence-based medicine is the conscientious explicit and judicious use of current best evidence in making decisions about the care of individual patients.”

In this particular case, I wanted to find some of the primary research done on CK levels in athletes in this age group.  Among the articles I pulled were two from CJSM:  “A Cluster of Exertional Rhabdomyolysis Affecting a Division I Football Team” , which was published in 2013; and a ‘Brief Report’ that was available only on-line until it was just published with the new, September CJSM, “Creatine Kinase Levels During Preseason Camp in National Collegiate Athletic Association Division-I Football Athletes.”

The former study I have actually profiled in these blog pages before.

There can be limits to the application of EBM in making decisions about ‘individual patients.’ For instance, in this particular case, my patient was a high school runner, and the articles I had pulled relate to college football players.   Certainly, on average, the CK levels in football players, because of their larger mass, will be higher than that seen in a runner.  That said, what I learned from the studies was very helpful; and, I thought, I could directly apply them to the patient in question.

First, in the cluster of exertional rhabdomyolysis cases, the CK levels were orders of magnitude higher in the affected individuals than in my on-call consult patient:  99K to 300K  CK levels were seen in the football players, and my runner had a level of 1.4 K. Still, textbooks will indicate that doctors may need to be concerned about CK levels about 200 (0.2 K).  And so, the question may remain:  in an asymptomatic athlete who is undergoing heavy training, what sort of CK levels might be normative?

The new ‘Brief Report’ went a long way toward answering that.  The findings a week into preseason football camp showed the mean CK levels for the 32 volunteer players was 1562.4 U/L (range 229-7453).  In other words, the mean was similar to what my consult patient was reported to have, and all the football players had levels above 200, a level which may, according to textbooks, be concerning.

As an on-call physician who had not laid eyes on the patient, I was reassured that the consulting physician had indeed screened the patient for myoglobinuria.  Armed with the evidence, I felt better placed to suggest a course of action; to wit:  let the patient rest a few days and go back to training, albeit at perhaps a slightly less intense level initially.  Specifically, he may want to avoid a lot of hill work right now, as eccentric quad contractions can, in particular, cause muscle pain and CK elevations.

The treating physician and I left it that I would hear back if the patient had persistence of pain and/or this plan didn’t work.

So…..when on-call, make sure you have your iPad and iPad app for ready access to the journal research.  It may just make your night a little easier.