As the authors in this retrospective review state, “Vertigo/dizziness is a common and challenging problem faced by the ER physician.” And, this is obviously true. Is it dysequilibrium? Is it true vertigo? Is it central or peripheral? And, finally, “now what”?
This is a clearly pro-MRI and con-CT study which, unfortunately, leads to a massive disconnect with reality. For most institutions, CT might be feasible, but MRI comes to town once a week for scheduled studies only. But, in this review of 448 head CTs for dizziness, the CT picked up essentially 10 interesting findings – but 16% of the subset of follow-up MRIs performed changed the initial diagnosis. Mostly, the missed diagnoses on CT were posterior circulation strokes and intracranial masses.
So, essentially what they observed was more false negatives than true positives for CT. This implies – at least in a retrospective fashion – that if your pretest probability is high enough for an intracranial process causing dizziness, the intention ought to be to conclude your investigations only with a negative MRI. I think most folks – given infinite resources – would agree. Otherwise, you’ll need to base imaging (if any) on clinical findings and risk factors for cerebrovascular disease in an attempt to develop an estimate for their true probability.
“Utility of head CT in the evaluation of vertigo/dizziness in the emergency department”
www.ncbi.nlm.nih.gov/pubmed/22940762
Month: November 2012
Unsurprisingly, NHAMCS Data is Flawed
The National Hospital Ambulatory Medical Care Survey is a massive database of abstracted patient records, systematically generated to produce a representative sample of the nation’s Emergency Department visits.
It should come as no surprise that retrospectively abstracted data from the electronic medical record sometimes fails to accurately reflect patient care. The important question, however, is “how often?” This review of NHAMCS by one of the Annals editors looked at a measurement that ought to be pretty obvious – intubation. If you can’t figure out whether a patient has been intubated via chart review, there’s some serious issues with your data sourcing. However, in this review of NHAMCS, the author interprets up to one in four charts as being potentially inaccurate due to inconsistencies between documented intubation and the final disposition of the patient (e.g., non-ICU settings, home, observation status, etc.)
Now, there are some instances in which patients are intubated in the Emergency Department – yet not subsequently dispositioned to a critical care or morgue – but these “temporary” intubations certainly do not constitute 25% of intubations. The author goes on to note that Annals publishes a NHAMCS study at least twice a year – relatively influential towards practice given the Impact Factor – and the flaws in this data should limit the relative weighting of its importance.
“Congruence of Disposition After Emergency Department Intubation in the National Hospital Ambulatory Medical Care Survey”
Sometimes, the Dead (by Ultrasound) Rise
This article received a little bit of dissemination, with the assertion that some apparently futile resuscitations may yet be salvaged despite the lack of cardiac activity on ultrasound.
But, this article doesn’t necessarily tell the entire story. It’s a systematic review of several small, poor-quality cardiac arrest cohorts for whom bedside cardiac ultrasonography was performed. In aggregate, there were 378 patients with no cardiac activity visualized during resuscitation – and 9 went on to have return of spontaneous circulation. They calculate this out as an LR of 0.18 for ROSC after finding no cardiac activity.
The problem is, this is the only information we have regarding the context of the ultrasound findings or the performance characteristics of the ultrasonographers at work. The authors also appropriately note that ROSC is not necessarily the ultimate patient-oriented outcome of interest – since we know that most ROSC after cardiac arrest admitted to the hospital still goes on to have a dismal outcome.
I’m not entirely sure what my takeaway should be from this study, and it’s not going to significantly modify my practice. In the appropriate clinical context, a lack of cardiac activity will still lead me to cease resuscitative efforts. It would be extraordinarily helpful to have a larger body of data specifically regarding the patient characteristics of those who did have ROSC despite lack of cardiac activity, to see if there is a usable pattern to this small population of exceptions.
“Bedside Focused Echocardiography as Predictor of Survival in Cardiac Arrest Patients: A Systematic Review”
PCA in the ED is Brilliant and Horrible
Management of acute pain in the Emergency Department is frequently inadequate. Considering the practice environment, the ebb and flow of workload, and the heterogenous presentations, this is not surprising. On the inpatient side of things, many patients with acute, severe pain receive patient-controlled analgesia. So, this is a randomized, controlled trial of PCA vs. conventional, untitrated boluses in the ED.
And, they were successful in demonstrating significant trends towards better, faster pain control and increased patient satisfaction with the PCA. Both groups received the same total amount of morphine, but the dynamics by which patients were able to self-titrate their pain control resulted in improved pain relief.
Unfortunately, there are some flaws with this study. This multi-center study only managed to enroll 96 patients in a one-year timeframe – probably the number we could aggressively enroll at my institution in a week. There is no mention of adverse events – which is significant, because PCA medication variances are renowned on the inpatient side as significant sources of morbidity. And, finally, they don’t measure any of the other operational variables that are important – cost, time to set up, etc.
Patient-controlled analgesia may yet have a role in the ED – and studies like this help keep the flame alive – but significant hurdles remain.
“A Randomized Controlled Trial of Patient-Controlled Analgesia Compared with Boluses of Analgesia for the Control of Acute Traumatic Pain in the Emergency Department”
www.ncbi.nlm.nih.gov/pubmed/23068783