Friday, November 4, 2011

Predicting Deterioration After Admission

This is a decidedly unsexy topic that I guarantee your Medical Director or QI committee cares about a lot.  Particularly where I work, we occasionally have a prolonged boarding event, the patient isn't reassessed in a certain time frame, the patient is transported out of the ED - and they arrive on the floor or step-down and Rapid Response is called for an unanticipated escalation in care.

This is apparently a bigger deal in the United Kingdom, because it is recommended by their government hospital body to employ a risk-stratification system to predict patient deterioration.  These two articles discuss the derivation in the UK and the validation in Canada of the "ViEWS" score, which is named in part by from their electronic health record that stores their physiologic data.  The general gist of the system is that the authors of the first article derived a score incorporating pulse, respiratory rate, temperature, systolic BP, O2 saturation, whether patient was on oxygen, and a measure of CNS alertness.  They then compare it do several other scoring systems and amazingly enough, the scoring system they derive - using the system from the company the authors' wives work for and in which they own shares of stock - works better than the other systems.

An abbreviated version of this is put into validation at a Canadian hospital that does not use any of the equipment, or have any financial conflict of interests.  They found equally good results - which, in summation they give as four risk-stratification groups:
 - < 3 points: 65% of all patients, only 0.02% died within 48 hrs.
 - 3-6 points: 28% of all patients, 0.41% died within 48 hrs.
 - 7-10 points: 6% of all patients, 3% died within 48 hrs.
 - >11 points: 0.7% of all patients, 13.8% died within 48 hrs.

So, yes, we all can probably look at the patients scoring >11 and know they're sick without a scoring system.  However, this might be a model to look at with nursing staff to help change the parameters for floor beds or to reassess which patients can be downgraded in order to free up more intensive resources upstairs.  Just don't necessarily buy the product being hawked by the original authors.

"ViEWS—Towards a national early warning score for detecting adult inpatient deterioration."
www.ncbi.nlm.nih.gov/pubmed/20637974

"Validation of an abbreviated VitalpacTM Early Warning Score (ViEWS) in 75,419 consecutive admissions to a Canadian Regional Hospital"
www.ncbi.nlm.nih.gov/pubmed/21907689

Thursday, November 3, 2011

Medication Errors During Resuscitation

According to previous literature from 2002, up to 19% of medication doses are administered in error to hospitalized patients.  Presumably, we've improved.

Apparently, we haven't.  This is a prospective observational study by pharmacists in Pittsburgh who observed the inpatient Medical Emergency Team in operation - which in this instance, was a physician-led team with "full" critical care capabilities, as opposed to their non-physician Rapid Response Team.  They observed medication administration during 50 of these calls and found that there were 1.6 errors per medication administration.  Yes, they really observed more than one error per dose - but 66% of those issues involved aseptic technique.  Subtracting those, they observed an error merely every other dose.  46% were prescribing errors, 28% administration technique, 14% mislabeling, 10% preparation, and 2% improper doses.  The authors eventually conclude that 14% of the total non-aseptic errors were truly harmful, not just "errors".

Despite the small sample size, I think it's a fair assessment that "medical emergency" situations can be chaotic and error-prone - and we still have a ways to go to implement systemic changes to prevent errors.

In the end, the pharmacists' solution is - more pharmacists.  Hmmm....

"Medication Errors During Medical Emergencies in a Large, Tertiary Care, Academic Medical Center"
www.ncbi.nlm.nih.gov/pubmed/22001000

Tuesday, November 1, 2011

Dabigatran Worsens/Does Not Worsen Bleeding

Stroke and Circulation are both Journals under the umbrella of the American Heart Association.  So, when they publish articles that come to contrasting conclusions, I find that entertaining.

Both of these articles are mouse models of bleeding on dagibatran, C57BL/6 or CD-1 mice.  Sadly, they are frighteningly complex in their adjustments and statistical analyses - which means it defeats my ability to concisely summarize the findings and methods.

In short, one of these articles looks at intracranial hemorrhage after collagenase injection for mice receiving several different doses of oral dabigatran, and compare it to controls, warfarin, lepirudin, fondaparinux, and heparin.  It appears, and the author's final conclusion is, that dabigatran is the least harmful of all anticoagulants - about halfway between controls and the other anticoagulants.  They also shoot the mice with lasers in another portion of the study, and dabigatran "wins" that as well.

The other article looks at trying to reverse dabigatran - which, if you recall the human study I posted a few weeks back, was not successful in humans.  However, human trials were all surrogate markers of bleeding as measured by laboratory measurements of clotting.  What entertains me is, in contrast to the other study, these authors have no trouble inducing bleeding and significant ICH formation with dabigatran.  In any event, once the mice were adequately bleeding, the authors compared prothrombin concentrate complexes (specifically, Beriplex), FFP, and FVIIa for treatment of ICH 30 minutes after induced injury with collagenase.  Happily, PCCs, in a dose-dependent manner, attenuated the induced ICH, while the others failed.

So, perhaps this "novel, reversible" anticoagulant has a treatment option for life-threatening bleeding.  Human confirmation, at least case reports, needed.

"Anticoagulation With the Oral Direct Thrombin Inhibitor Dabigatran Does Not Enlarge Hematoma Volume in Experimental Intracerebral Hemorrhage"
http://circ.ahajournals.org/content/early/2011/09/11/CIRCULATIONAHA.111.035972.abstract

"Hemostatic Therapy in Experimental Intracerebral Hemorrhage Associated With the Direct Thrombin Inhibitor Dabigatran"

Monday, October 31, 2011

Sodium Polystyrene Sulfonate For Lithium Toxicity

This one is for @drsamko, thanks to his tweet yesterday.  


The most recent of 19 articles in pubmed for the search "sodium polystyrene sulfonate lithium", a retrospective cohort review looking at the use of SPS in the treatment of lithium toxicity.  Given that lithium and potassium are similarly charged cations, multiple animal studies evaluated its use in lithium overdose, but only case reports in humans.  These authors reviewed 9 years of cases at their institutions, two hospitals in Montreal, Canada, for the effect on lithium serum half-life between patients prescribed SPS vs. patients who were not prescribed SPS.


They only looked at chronic overdoses admitted for management - 90 patients, 72 chronic, 48 had data points to properly evaluate the half-life.  36 received "standard treatment" and 12 were prescribed SPS.  The authors don't well-describe the standard treatment group, and don't indicate whether any received hemodialysis - but I get the impression the treatment for chronic toxicity only employs HD on rare occasions of renal failure.  Of the 12 that received SPS, most simply received IV hydration and observation in addition to SPS - and one received hemodialysis due to renal failure.  Half-life of lithium in the controls was 43 hours compared to 20.5 hours in the SPS-receiving group.


SPS isn't totally benign - there was mild hypokalemia in half their treatment population - and in rare cases it causes intestinal necrosis.  And, considering chronic lithium toxicity generally has a benign course, you could go either way.  You can certainly argue that decreased hospital length-of-stay is a significant financial and health benefit and justify giving it, though, so it's worth knowing about.


"Successful treatment of lithium toxicity with sodium polystyrene sulfonate: a retrospective cohort study"
www.ncbi.nlm.nih.gov/pubmed/19842945