Thursday, March 6, 2008

Spinal cord compression; COPD prognosis; More

Briefies, in no particular order:


JAMA has a 'clinicians' corner' piece about spinal cord compression. It is a practical, chatty, overview of the topic and a good one for the teaching file. It discusses the controversies surrounding optimal glucocorticoid dosing as well as who should get surgery. The tone and focus of these clinicians' corner pieces tends to be patient-centric, and this one exemplifies that: it confronts the topic from a patient's perspective, and it's always refreshing to see this in such medical literature.

An excerpt from the prognosis section:
Median survival after spinal cord compression depends on the patient's tumor type, ambulatory status, and number and site of metastases. Patients with a single metastasis, a radiosensitive tumor, or with myeloma, breast, or prostate cancer have the longest survival, while patients with multiple metastases, visceral or brain metastases, or lung or gastrointestinal cancers have the shortest. Even patients with responsive tumors, such as myeloma, lymphoma, and breast cancer, have relatively short median survivals of 6.4, 6.7, and 5 months, respectively; survival of patients with prostate or lung cancer is only 4 and 1.5 months, respectively. One-year survival rates for patients with spinal cord compression due to multiple myeloma, lymphoma, and breast and prostate cancers were 39%, 38%, 27%, and 22%, respectively, while that of lung cancer patients was 4%.
For COPD prognosis completists: The European Respiratory Journal has a study on the 6 minute walk distance test (basically the number of meters one can walk in 6 minutes in a controlled environment) & prognosis. The main purpose of the study is to compare various cut offs for normal 6MWD results, but it also gives some general prognostic information as well, although not with a precision necessary to help with decisions about hospice admission etc (no validated prognostic index/marker in COPD has been able to do this as far as I know). The data come from ~1300 patients followed across many years (potentially up to a decade) until they died (most were followed for about 5 years) and looks at their baseline 6MWD test and survival. 66% of patients with 6MWD of less than 350 meters (their threshold for defining a 'poor prognosis') died during the study (compared to 30% of those who had 6MWD over 350 meters). Frustratingly they don't actually say what the mean or median survival was; the time to 50% mortality, etc. - this 66% is just 'during the study time frame' (i.e. the 350 meter threshold is helpful for dividing 'better' and 'worse' prognosis but that's about it from how these data are presented). Tantalizingly they describe a relatively linear relationship between 6MWD and prognosis - with those with the worst results (less than 100 meters) having nearly a 90% mortality during the study...given that the mean follow up was 5 years you could kinda say this is a near 90% 5 year mortality but only kinda. This is one of the frustrating elements of reading the literature from a 'palliativist's' (as Christian likes to say) perspective and not from, say, a pulmonary researcher's perspective: what's important to them is not the same as what's important to us....

JCO has an art of oncology piece looking at whether lying is easier than truth-telling when giving bad news. The actual study (which is presented in the 'art of oncology' section and without the usual research reporting rigors) involved 67 Greek medical students (all male for some reason) who were monitored and reported on their anxiety before and after a structured interview with a standardized patient. The scenario was that the standardized patient had just been diagnosed with recurrent brain cancer, had a short prognosis, etc.; some subjects were randomly assigned to being instructed to hide the truth from her (but refer her for treatment), others assigned to telling her the full truth, and the final group assigned to offer her dietary advice (as some sort of control). Basically the found that the full disclosure group disclosed more anxiety during and after the interview, and had more signs of it as well (elevated heart rate) compared with the 'lie to her,' and dietary groups. The authors conclude that one reason for concealing information from patients is to protect our own emotions/reduce our anxiety. Besides the obvious limitations here (young medical students, fake patient, the Greek factor, etc.) one also wonders if we actually needed a study to tell us that docs don't disclose the full truth to protect ourselves/our own emotions! On the other hand, why not try to prove it? I am hopeful this will form one tiny part of what appears to be a growing body of research which will show most patients want to know the truth, most patients actually measurably and materially benefit from knowing the truth, and we should stop making excuses for not doing it. I think this is what the research is showing, and I hope it will continue to show that (although it will be interesting and challenging if it doesn't). The caveat here is the "most"- most patients want to know the truth etc. - how to identify and what to do with those that don't? That's an interesting question....

Pain Medicine has a study looking at the long-term side effects and tolerability of oral ketamine. By long term I mean 3 months, and by oral I mean 30mg five times a day. The data are observational and are from ~30 patients who were given IV then oral ketamine for chronic neuropathic pain. There is very little data about the tolerability and side effects of long term ketamine so this study is a valuable, although it fails to answer many basic questions. Findings: 12% of patients discontinued treatment due to intolerable side effects, and most patients had some side effects (dizziness 22%, sedation 19%, dry mouth 18%). None had hallucinations or hepatotoxicity or vascular side effects (hypertension). They gave no indication if side effects attenuated over time or anything like that and one assumes that 22% of patients at some point reported dizziness but it's unclear for how long, etc. My gloss on all of this is that many patients probably tolerated the ketamine just fine. Whether it was an effective analgesic cannot be answered by these observational data.

I'll also note that the article was written with a slightly off-kilter and charming use of the English language. Example:
Although a consensus in the strategy of its antineuralgic therapy has not been achieved (application form, minimal and maximal dose, dosage frequency, contraindications), it is clear now that the analgesic doses are significantly lower then [sic] the anesthetic doses. However, there have been reported some cases of side effects of high doses of ketamine that was administered for a long time. On the other hand, the concerns regarding the undesirable effects which are known from the anesthesiology have been cleared (hallucinations, activation of sympathetic system, salivation). These undesirable effects practically do not occur with the analgesic dosage. However, it has to be admitted that even the low doses of ketamine have their specificities which may surprise not only the patient but also the physician.
And even more briefly...

Annals of Internal Medicine has published ACP clinical practice guidelines on the pharmacologic treatment of dementia (associated evidence review here). Summary: yeah most of the agents used show statistically significant benefit in the studies but we're unsure if any of this is clinically relevant.

The same issue also has some letters responding to the advance directives paper from several months ago. From the cheekiest:

I would like to share an observation from a primary care practice of more than 30 years. During this time, I have offered advance directives to all my patients.... Although few have completed the advance directive, essentially all patients have expressed the wish to forgo life support in a situation that looks hopeless.... On the basis of this observation, I think the greatest flaw in the concept of advance directives may be the underlying assumption that, unless otherwise indicated, people want to be kept alive in such conditions as a persistent vegetative state. It might make more sense to continue to make advance directives available to everyone, but to shift the burden of necessary documentation to those rare individuals who want to continue care that seems futile to their medical providers.

Clinical Journal of the American Society of Nephrology has a discussion of dialysis withdrawal in the ICU in light of the ASN's 'Shared Decision-Making in the Appropriate Initiation of and Withdrawal from Dialysis' position piece.

There was also this commentary in JAMA - which has nothing to do with palliative care - but is nevertheless an interesting read: it has a little about the history of psychopharmacology, muses about the relationship between serendipitous clinical observation and advancing knowledge, and discusses alternatives to the hallowed randomized placebo controlled trial, etc. It's a commentary about how knowledge is generated - how we figure things out - and I liked it.

This is probably too much for one post - sorry.

Pallimed | Blogger Template adapted from Mash2 by Bloggermint