Blog | Friday, December 2, 2011

Dealing with cyclic vomiting syndrome given how little is known about the condition

I have been working as an ER doctor for over a decade, and in that time I have come to recognize that there are certain complaints, and certain patients who bear these complaints, that are very challenging to take care of. I'm trying to be diplomatic here. What I really mean is that there are certain presentations that just make you cringe, drain the life force out of you, and make you wish you'd listened to mother and gone into investment banking instead. Among these, perhaps most prominently, is that of the patient with cyclic vomiting syndrome.

The diagnosis of cyclic vomiting syndrome, or CVS, is something which is only in recent years applied to adult patients. Previously, it was only described in the pediatric population. It has generally been defined as a disease in which patients will have intermittent severe and prolonged episodes of intractable vomiting separated by asymptomatic intervals, over a period of years, for which no other adequate medical explanation can be found, and for which other causes have been ruled out.

That is not much in the way of good literature about this disease entity, which is surprising, because it is something that I see in the emergency department fairly regularly, and something with which nearly all emergency providers are quite familiar. These patients are familiar to us in part because we see them again and again, in part because they are memorable because they are so challenging to take care of.

Some things about the cyclic vomiting patient that pose particular challenges:
--The intensity of their vomiting symptoms tends to be very severe, and refractory to most standard antiemetics.
--The amount of affective distress the patient demonstrates is usually quite disproportionate to the severity of their symptoms, which is actually saying something, since they can at times be fairly ill. This often manifests itself as a patient who is ultra-dramatic, writhing on the gurney, or hyperventilating and sobbing in a knee to chest position, refusing to talk to the care providers. This can create the perception among care providers that the illness is psychogenic, a perception which is reinforced by the fact that there does seem to be significant association between CVS and mental health diagnoses.
--Patients often will engage in behaviors which seem to be willfully making their symptoms worse, such as compulsively drinking water or being seen to induce vomiting by putting their fingers down their throat.
--Coexisting with the vomiting is often a fairly severe complaint of abdominal pain, for which no clear diagnosis can be established, requiring in some cases high doses of intravenous narcotics. CVS patients are interesting in that sometimes the only agent that will stop the vomiting is hydromorphone. (For the nonmedical readers, it is worth noting that hydromorphone has no anti-vomiting properties, and in fact causes many people to vomit.) This requirement for narcotic medication supports a perception that the patient is drug addicted or drug seeking, itself reinforced by the fact that patients tend to come back to the emergency room several times in quick succession for recurrent vomiting. (For this reason, some have referred to CVS as an "abdominal migraine.")

All of this makes management difficult in the setting where there is fairly little in the way of evidence-based guidelines, or even much in the way of expert recommendations or academic agreement on the definition of the syndrome.

My observation, over the years, is that while Zofran and Reglan and Compazine can in some cases be helpful, in most cases they are not. I have however, had very good success with the use of benzodiazepines such as lorazepam or midazolam. Benzodiazepines seem to work in two ways: they are well known to have anti-emetic properties, but they are also quite sedating, and the patient does need to be awake to vomit.

Interestingly, while use of normal vomiting medications seems to drive patient requests for narcotic medications, when I use the benzodiazepines, I almost never have to co-administer a narcotic. Since I have made these observations and implemented them in my personal standard treatment protocol, I found that CVS patients are much easier to care for, both in the sense that they're less emotionally draining for me and in the sense that they get better quicker and go home feeling better. It's not clear to me whether this treatment protocol results in fewer bounce-back presentations to the emergency room, but I would be very interested to find out if that is the case. (Interestingly, the use of hydromorphone seems to increase the likelihood of bounce-back presentations.)

I'm a little curious whether propofol could be used to manage the vomiting of CVS, since it is also known to have anti-emetic properties, but given the demise of poor Mr. Jackson, I suspect such off-label uses of that medication are not going to be encouraged.

One thing which I've recently become aware of, in part through our good Aussie friends at Life in the Fast Lane and in part from a journal club that I recently attended, is that there seems to be a fairly strong association with marijuana use and CVS. In fact, there has been proposed a disease entity called cannabinoid hyperemesis syndrome which may possibly represent the same clinical syndrome of CVS, or at least a significant overlap. This is particularly interesting because marijuana is in fact generally perceived to have antiemetic properties. Leon Gussow, a toxicologist who blogs at The Poison Review, has a nice write up over at Emergency Medicine News, where he speculates:

Because cannabinoids are lipophilic and have long half-lives, they may accumulate with chronic heavy use to the point where they start to exert a paradoxical effect. This may be related to their well-described ability to delay gastric emptying and decrease gastrointestinal motility.

However, I would temper that against the observation that in CVS patients gastric motility and gastric emptying is often increased.

Since I have become aware of this association between marijuana use and CVS type presentations it has been my "good fortune" to care for nearly a dozen patients in the emergency department who self-reported diagnosis of CVS. Curiously, of these patients about 10 admitted active marijuana use, and the two who denied it had positive urine screenings for marijuana. This does not exactly make a case series, but is certainly another interesting observation. Of course, since the prevalence of marijuana use in our Emergency Department seems to approach 100% sometimes, this also may not be a statistically significant association! Each of these patients was counseled about the possible causal relationship and advised to stop smoking the devil weed. Lord knows whether they will or not, but maybe it will actually do something to reduce their ER visit frequency.

I'd be interested to hear your observations on this matter, whether other ER folks have noticed the same thing.

This post by Liam Yore, MD, appeared at Get Better Health, a network of popular health bloggers brought together by Val Jones, MD. Better Health's mission is to support and promote health care professional bloggers, provide insightful and trustworthy health commentary, and help to inform health policy makers about the provider point of view on health care reform, science, research and patient care.