Friday, May 27, 2011

Red Cell Distribution Width... Means What Now?

"Red cell distribution width is a robust predictor of... all-cause patient mortality."

I saw this article when I was browsing abstracts, and I thought, "Huh!  That sounds interesting, though, probably not relevant."

So, yes, increasing red cell distribution width is associated with increased mortality.  However - and this is something I've never seen before in an article - looking at the table describing the differences between their various divisions of RDW% - every other descriptive statistic is different between groups.  More septic patients with high RDW%.  More renal failure.  Differences in hematocrit.  More organ failure.  They claim by statistical multivariate massage, that RDW shakes out as an independent factor, but, sheesh...it's almost like saying decrease in temperature is highly associated with death, when they're cold because the blood isn't circulating, the breathing has stopped, the brain has shut down, etc....

Another fine example of where reading the abstract is absolutely no replacement for perusing the article.

http://www.ncbi.nlm.nih.gov/pubmed/21532476

Thursday, May 26, 2011

Pediatric Septic Shock Protocol

Another sort of goal-directed sepsis study, this time in Pediatrics at Primary Children's.  They implemented a protocolized triage system in their ED designed explicitly identify more cases of sepsis - which led to increased percentages getting early fluid resuscitation, early lactate level measurements, and more frequently antibiotics in the first three hours.

But the net effect of all these interventions...the only detectable difference in their 345 patient cohort was improved length-of-stay for survivors, from IQR 103-328 hours pre-intervention to IQR 86-214 post-intervention.  Total hospital costs were not significantly different.  No change in mortality - which was already low at 7%.

So, yet again - adherence to "quality measures" has debatable clinical significance.

Wednesday, May 25, 2011

Procalcitonin Misleads Antibiotic Therapy In Sepsis

An important negative study of an inflammatory biomarker that's been getting a fair amount of push.

It is absolutely true that procalcitonin levels may be elevated in an inflammatory states such as sepsis.  This group tried to make a clinically relevant protocol for procalcitonin trends by saying, if the procalcitonin level is not decreasing with current therapy, then antibiotic coverage should be expanded and aggressive testing should be undertaken to evaluate for missed source control.

Unfortunately, in the treatment arm where procalcitonin was used in clinical decision making, there was extensively greater broad-spectrum and multiple-antibiotic utilization without any demonstrated mortality benefit.  In addition, LOS and ventilator-depended days were longer in the procalcitonin arm.

There were very minor differences between the two groups, probably favoring the control, but not nearly enough to suggest that procalcitonin has any value in assessing failure of current therapy.

http://www.ncbi.nlm.nih.gov/pubmed/21572328

Tuesday, May 24, 2011

Massachusetts Health Reform Is "Working"

By some measures, at least, you can claim that the Health Reform is working.  I've seen a few articles out there saying it failed, because ED visits continue to rise.  But, if this study is reliable, the increases in ED utilization are a result in increased illness severity, not inability to access a physician.

Non-acute visits for the uninsured/low-income cohort in Massachusetts went down, from 43.8% to 41.2% - a greater decrease as compared to their "control" group of private insurance that is supposedly unaffected by health reform, which decreased from 35.7% to 34.9%.  So, one way to interpret this is that increased access has kept some of the non-urgent uninsured out of the ED.

...but they're still seeing, by their definition, a solid nearly 40% of patients in our EDs that have less than a 25% of requiring true Emergency Department care.  So things have incrementally improved - but the problem is not simply that a patient has nominal access to a PMD, they actually need to be able to access that PMD on a semi-urgent basis to truly reduce ED utilization...and that PMD needs to be more than simply a revolving door back to the ED.

http://www.ncbi.nlm.nih.gov/pubmed/21570157

Monday, May 23, 2011

Early Antibiotics Show No Benefit in Sepsis

Interesting analysis of the EMSHOCKNET cohort, looking to see if there was any association between time to antibiotic administration and survival benefit in septic shock.

And, no.  Earlier antibiotic administration, as measured by arrival time in the the ED, showed no significant impact.

They do another secondary analysis where they try to say, well, if the patient received antibiotics before they met criteria for septic shock - then they had a 2.59 (1.17 - 5.74) OR for survival.  I'm not sure how to interpret this finding - perhaps because they looked at 10 different cut-off points for antibiotic administration, they found one that favored antibiotics by chance.

Or, perhaps antibiotics really aren't the lynchpin in treating sepsis - if you can give antibiotics ahead of SIRS, perhaps you have a milder case - but once you have end-organ dysfunction, the interventions that target improving the physiologic changes of sepsis are more important.

http://www.ncbi.nlm.nih.gov/pubmed/21572327

Sunday, May 22, 2011

Delivering Clinical Evidence

These are a couple interesting commentaries regarding the state of clinical evidence and the difficulty of applying it at the point of care.  One, from the BMJ, worries about the sheer number of studies and trials being generated, and that the data will never be able to be appropriately digested, and we'll all die slow deaths from information overload.  And, to some extent, this is true - how many of us carry around "peripheral brains" in our pocket?  Before smartphones, it was the Washington Manual or Tarrascon's, and now we have MedCalc, Epocrates, etc.  And, we desperately try to simplify things so we can wrap our brains around it and integrate it into a daily practice by distilling tens of thousands of heterogenous patients into a single clinical decision instrument like NEXUS, CCT, CHADS2, etc.  While this is better than flailing about in the dark, it's still repairing a watch with a hammer.  These tools tell us about the average patient in that particular study, and have only limited external validity towards the patient actually sitting in front of us.

Dr. Smith's BMJ article proposes the "machine", which is a magical box that knows all and provides seamless patient-specific evidence.  Dr. Davidoff isn't sure that's feasible, and, as a stopgap measure, promotes the rise of the informatician or medical librarian, a new role for utilizing the available electronic health databases.  This librarian will be expert in reading medical literature, will be expert in data mining healthcare information systems, and discover the most relevant ways to target quality and guideline improvement initiatives.

They're both right, in a way.  And we should definitely train and mature the growing discipline of this clinical informatician while we keep working on the magic box....

http://www.ncbi.nlm.nih.gov/pubmed/21558524
http://www.ncbi.nlm.nih.gov/pubmed/21159764