The Slow Death of the Lumbar Puncture

As modern CT scanners become more sensitive, the ability of scanners to discriminate smaller and small abnormalities – such as spontaneous aneurysmal subarachnoid hemorrhage – continues to increase.  This BMJ paper makes another case for forgoing lumbar puncture in patients with a negative CT scan.

Specifically, they say that all the SAH in their cohort was picked up by a 3rd generation scanner as long as the scan was performed within six hours of headache onset.  Unfortunately, this is another one of those studies that uses follow-up as a proxy for the gold standard evaluation – only half of their enrolled cohort underwent lumbar puncture.  They followed up their patients for six months, but survival at six months doesn’t rule out pathology, it only rules out death from that specific pathology, and only if an autopsy was performed.

But, CT scan is starting to get close to the point where the false negatives of CT are equivalent to the false positives of the lumbar puncture – and I would imagine the costs and harms to the patient begin to approach equivalence.  It definitely changes the equation for your patients when you come back with a negative CT scan and your patient wants to know what the chances are they really need this lumbar puncture.

“Sensitivity of Computer Tomography Performed Within Six Hours of Headache For Diagnosis of Subarachnoid Haemorrhage: Prospective Cohort Study”
www.ncbi.nlm.nih.gov/pubmed/21768192

High-Risk Discharge Diagnoses

Good news – only 0.05% of your discharged patients will meet an untimely end within 7 days of the Emergency Department visit.  Not a frightening number, but definitely enough to keep you on your toes.

It’s a retrospective Kaiser Health System cohort of 728,312 visits across two years, and the authors calculated the base rate of 50 per 100,000, as well as looking at other features and discharge diagnoses that increased the OR for death within 7 days.  And, even the sickest, most elderly have OR that are low enough that you’re still going to have good outcomes the overwhelming preponderance of the time.  Age greater than 80 gives an OR of 10.6 and a score >3 on the Charlson Comorbidity Index gives an OR of 6.7.  As for the diagnoses they found that are most highly associated with bad outcomes – the only two with OR great than 5 are noninfectious lung disease (OR 7.1) and renal disease (OR 5.6).  These are kind of interesting buckets of diagnoses, specifically in the sense regarding how nonspecific they are – which the authors attribute to diagnostic uncertainty.  I.e., the reason why patients had bad outcomes with “noninfectious lung disease” is because clinicians missed finding the specific morbid diagnosis in these patients.
I don’t think this is practice-changing news, since these rates are so low in general that additional testing and hospitalization will harm more people than these missed diagnoses – but it’s an interesting number crunch article.
“Patterns and Predictors of Short-Term Death after Emergency Department Discharge”

Against Medical Advice

This is a nice review article that shows a mix of different issues associated with signing a patient out AMA.  It’s a strange practice environment we have here, where EM is turning into an increasingly customer-centric practice specialty – yet unless we have airtight documentation, our customers can litigate against us for the choices they make.

In principle, our patients have the autonomy to make their own decisions – but our cultural values have drifted away from accepting responsibility for our actions.  To best protect ourselves, the authors recommend using a specific AMA form – not because having the patient’s signature on a form confers any extra legal protection, but because it’s a structured document that helps remind clinicians to document the two key elements of the AMA:  that the patient had medical capacity to make the decision, and that the patient was adequately informed of the risks.   After you satisfy both those conditions, the key is simply complete documentation in the medical record, and you should be afforded some protection given the patient has now terminated the legal duty to treat and assumed the risk for further poor outcomes.

“The Importance of a Proper Against-Medical-Advice (AMA) Discharge”
www.ncbi.nlm.nih.gov/pubmed/21715123

Physicians Will Test For PE However They Damn Well Please

Another decision-support in the Emergency Department paper.

Basically, in this study, an emergency physician considered the diagnosis of pulmonary embolism – and a computerized intervention forced the calculation of a Wells score to help guide further evaluation.  Clinicians were not bound by the recommendations of the Wells calculator to guide their ordering.  And they sure didn’t.  There were 229 patients in their “post-intervention” group, and 26% of their clinicians said that evidence-based medicine wasn’t for them, and were “non-compliant” with their testing strategy.

So, did the intervention help increase the number of positive CTAs for PE?  Officially, no – their trend from 8.3% positive to 12.7% positive didn’t meet significance.  Testing-guideline complaint CTA positivity was 16.7% in the post-intervention group, which, to them, validated their intervention.

It is interesting that a low-risk Wells + positive d-Dimer or high-risk Wells cohort had only a 16% positive rate on a 64-slice CT scanner – which doesn’t really match up with the original data.  So, I’m not sure exactly what to make of their intervention, testing strategy, or ED cohort.  I think the take home point is supposed to be, if you you can get evidence in front of clinicians, and they do evidence-based things, outcomes will be better – but either this just was too complex a clinical problem to tackle to prove it, or their practice environment isn’t externally valid.

Should Rural Health Care Be Equivalent?

“All residents in the United States should have access to safe, high-quality health care and should have confidence in the health care system regardless of where they live.”

That is the final statement of the accompanying editorial to the JAMA article documenting superiority in outcomes in urban hospitals vs. critical care access rural hospitals for acute MI, CHF, and pneumonia.  The acute MI study population is slightly more ill at baseline in the rural hospital sample, but the groups are otherwise similar.  Raw mortality is higher for AMI (26.1% vs 23.9% adjusted), CHF (13.4% vs. 12.5%) and pneumonia (13.0% vs. 12.5% [not significant]) favoring urban hospitals.

The key feature – critical access hospitals were less likely to have ICUs, cardiac cath, surgical capabilities, and had reduced access to specialists.  Is it any wonder their outcomes are worse?  As someone who moonlit in one of these hospitals as a resident, I can guarantee the standard of care in a rural setting is lower.

But, coming back to the original supposition – is it realistic to dedicate the funding and resources to bring rural hospitals up to the standard?  To equip far-flung hospitals with the same standard of care as urban settings to cover the remaining 20% of the population is likely simply an unfeasible proposition.  Living in rural areas is simply going to come with the risks associated with unavoidable delays in care and reduced access to specialists and technology.

“Quality of Care and Patient Outcomes at Critical Access Rural Hospitals”
www.ncbi.nlm.nih.gov/pubmed/21730240
“Critical Access Hospitals and the Challenges to Quality Care”
www.ncbi.nlm.nih.gov/pubmed/21730248

It’s Impossible To Catch All Pediatric Pneumonia

Another glass half-full vs half-empty, depending on how you read it.  Their editor capsule summary says “Children without hypoxia, fever, and ausculatory findings are low risk.”  The numbers say – in the absence of hypoxia, fever, or focal ausculatory findings, radiographic pneumonia was seen in 7.6% (CI 5.3-10.0).  Interesting numbers that, to me, say that pediatric pneumonia is still a black box of uncertainty.

However, what the authors call “definite” pneumonia was only 2.9% in the absence of those findings, and the editor’s capsule conclusion is that low-risk patients are best served by follow-up rather than radiology.  And, this is where the half-full/half-empty comes in – because a lot of EPs don’t want to the guy that sends home pneumonia even in a “low risk” situation, given than 30% of their pneumonia diagnoses required admission.  I’d rather take the half-full approach – recognizing that the majority of radiographic pneumonias are viral anyway, and, if the patient has adequate follow-up and tunes up nicely, do my best to avoid unnecessary testing in a low pretest probability setting that will end up with more false positives and unnecessary antibiotics.

“Prediction of Pneumonia in a Pediatric Emergency Department”

Does EHR Decision Support Make You More Liable?

That’s the question these JAMA article authors asked themselves, and they say – probably.  The way they present it, it’s probably true – using the specific example of drug-drug interactions.  If you put an anticoagulated elderly person on TMP-SMX and they come back a few days later bleeding with an INR of 7, you might be in trouble for clicking away the one important drug alert out of the one hundred you’re inundated on your shift.  The authors note how poorly designed the alerts are, how few are relevant, and “alert fatigue” – but really, if you’re getting any kind of alerts or have any EHR tools available to you during your practice, each time you dismiss one, someone could turn it around against you.

The authors potential solutions are an “expert” drug-drug interaction list or legislative legal safe harbors.

“Clinical Decision Support and Malpractice Risk.”
www.ncbi.nlm.nih.gov/pubmed/21730245

“Narcotic Bowel Syndrome”

I had never heard this specific diagnosis bandied about in an Emergency Medicine context – but, essentially, it’s a gastroenterology entity (and diagnosis of exclusion) that entails, essentially, chronic, intractable, crampy abdominal pain of unknown etiology and concurrent narcotic use.  I can’t even describe how many of these patients I saw each shift during residency – and how many of those people had multiple CT scans in the past year.  The key feature in this particular diagnosis, as described in their case, is they had extensive follow-up evaluation, were weaned from their narcotics, and had resolution of symptoms.

I think this is a diagnosis spectrum we see a lot in the ED – whether it be constipation, IBS, cyclic vomiting syndrome, “feeling sick”, or the multitudinous abdominal pain of unknown etiology.  With more and more patients being prescribed (or secretly taking) narcotics, what we see in our EDs is not just the overdose emergencies, but the various side effect spectrums of dependence and withdrawal.

You’d think that with all our medical technological prowess we’d have better mechanisms to treat pain than they did thousands of years ago.

“Narcotic Bowel Syndrome”
http://www.ncbi.nlm.nih.gov/pubmed/21719232

Endotracheal Tube Verification Via Ultrasound

I think I’ve discovered the new paradigm of research in ultrasound.  Every time you do a procedure or make a diagnosis, slap the ultrasound on someone and see if you can reliably identify anatomic changes.

It looks like, with their practiced ultrasonographers, that they can get some preliminary information regarding endotracheal tube placement by performing transtracheal ultrasound.  Their “gold standard” was waveform capnography – which is a fair gold standard, but not universally sensitive and specific for tube placement in all clinical situations.  Essentially, if the ETT is in the correct place, there is only one “air-mucosal interface” observed with high-frequency linear probe, and, if the ETT is in the esophagus, you have a second, posterior air-mucosal interface.

Seems reasonable.

Experts did it correctly with 99% sensitivity and 94% specificity, and the main advantage was speed.

“Tracheal rapid ultrasound exam (T.R.U.E.) for confirming endotracheal tube
placement during emergency intubation.”

Online Publishing of ED Wait Times

When a small city only has two Emergency Departments, you can run a study like this to see what effect publication of ED wait times has on visits.

While it is fabulously logical that if 18 to 40 people a day are looking at your Emergency Department wait times that some portion of those people will choose a facility with a shorter wait time – or choose not to come to the ED at all – or choose to come in when they might not have otherwise come in if the wait time is short – this study doesn’t actually try to study the population of interest.  They need to somehow capture individuals who are using the published information to make decisions, rather than looking generally at their overall wait time statistics – because, even though they say their results “were consistent with the hypothesis that the publication of wait time information leads to patients selecting the site with shorter wait time”, they are making a huge unsubstantiated leap.

Looking at their descriptive statistics, hardly anything changed to actually justify their conclusions, and, really, it looks like patients just based their decisions pretty heavily on which of the two hospitals was closer – particularly Victoria Hospital, which people only went to if it was nearer.  I do also find it fascinating that their mean wait time rose from about 105 minutes to 115 minutes, yet the amount of time their wait time was >2 hours (120 minutes) actually dropped from 13% to 9%.  This is how they justify their conclusion that the “spikes” are mitigated by online usage – and it may be true – but there are too many moving parts and they aren’t actually asking people if they used the website and used the information from it.

“The effects of publishing emergency department wait time on patient utilization patterns in a community with two emergency department sites: a retrospective, quasi-experiment design.”
http://www.ncbi.nlm.nih.gov/pubmed/21672236