Wednesday, July 27, 2011

The anticoagulation forum

This is an educational resource on topics related to antithrombotic therapy. Archived webcasts of the 11th National Conference on Anticoagulant Therapy are posted.

Pure quackery invades a critical care nursing journal

Appreciating hospitalists for (gasp!) their clinical skills

Since its origins the hospitalist movement has been redefined. According to our founding documents a hospitalist was a generalist physician, usually an internist, who brought exceptional clinical skills to the care of hospitalized patients. Emphasis on the word clinical. Things devolved considerably since then. Clinical expertise gradually took a back seat to clerical skills, coding and performance measures. Today our thought leaders, or many of them, seem to devalue clinical expertise.

I'm not generally impressed by promotional items about hospitalists, but a recent post by Dr. John M got my attention because it focused on hospitalists as excellent clinicians:

But for good patient care, the details are important too. Hospitalists are good at details. In fact, an internists’ area of expertise is in using, considering and synthesizing such specifics. They mesh together a patient’s history, exam, laboratory values, X-rays, and other specialists’ opinions. I feel strongly that having thinkers on the case is a good thing.

Tuesday, July 26, 2011

What's wrong with performance measures?

In large part they are substitutes for thought. That's why they are so faulty and so many docs resist them.

CT angiography is not the diagnostic modality of choice for PE

A recent study published in Chest evaluated the sequence of clinical scoring, D-dimer testing, compression ultrasonography, V/Q scanning and CT (MDCT) in that order for the diagnosis and rule-out of PE. CT was only needed in 11% of the patients:

Results: Detection of DVT by ultrasonography established the diagnosis of PE in 43 (13%). Lung scan associated with clinical probability was diagnostic in 243 (76%) of the remaining patients. MDCT scan was required in only 35 (11%) of the patients. The 3-month thromboembolic risk in patients not given anticoagulants, based on the results of the diagnostic protocol, was 0.53% (95% CI, 0.09-2.94).

Conclusions: A diagnostic strategy combining clinical assessment, d-dimer, ultrasonography, and lung scan gave a noninvasive diagnosis in the majority of outpatients with suspected PE and appeared to be safe.

Well, I'm going to savor this moment for a little self aggrandizement. I told you so. I've been hammering this point for the last six years on this blog. The evidence has never favored CT over V/Q for PE. Minimizing the use of CT in the evaluation of patients for PE will save costs, radiation risk and kidneys.

Review of therapeutic hypothermia after cardiac arrest

Here's a nice update from CCJM with free full text and CME available.

Points of interest:

For neurologically appropriate patients (GCS less than 8) the intervention carries a class I recommendation in the 2010 ACLS guidelines when the cardiac arrest was out of hospital and the initial rhythm was VF or pulseless VT and spontaneous circulation was restored in less than 60 minutes.

For all other rhythms and for in hospital arrest of any rhythm the intervention is given a class IIb recommendation.

Patients without obvious extracardiac cause for their arrest need prompt coronary angiography. Therapeutic hypothermia can be implemented in parallel with cardiac catheterization, with the protocol started before or during the procedure.

All bets are off for estimating neurologic prognosis until 72 hours after rewarming.

Monday, July 25, 2011

Trends in elective PCI post-COURAGE

It looks like cardiologists are following the evidence according to this new study:

Conclusions—Publication of results from the COURAGE trial was temporally associated with a significant and sustained decline in the use of PCI to treat patients with stable angina. The long-term impact of this change in practice on patient outcomes remains to be determined.

Unexplained AV block in younger patients: think beyond the pacemaker!

In this recent paper investigators found a surprisingly high prevalence of cardiac sarcoidosis and giant cell myocarditis among patients aged 18-55 with unexplained AV block requiring pacing:

Conclusions—CS and GCM explain greater than or equal to 25% of initially unexplained AVB in young and middle-aged adults. These patients are at high risk for adverse cardiac events.

A high rate of adverse events was noted in follow up of the CS and GCM patients. In contrast, those patients whose heart block remained idiopathic after investigation had a benign course.

The Clinical Perspective piece related to this article stated:

These data suggest that CS and GCM are not uncommon causes of AVB in young and middle-aged adults and that the prognosis of CS and GCM is poor even when the first manifestation is AVB. We encourage a policy of active and systematic screening for CS and GCM in all adults aged less than 55 presenting with unexplained high-degree AVB.

Benign versus malignant early repolarization---can they be distinguished?

The early repolarization pattern on the electrocardiogram was long considered a benign variant. Recent evidence suggests a subset of patients in whom it signifies an increased risk of sudden cardiac death. I blogged on that topic here and here.

A recent study addressed electrocardiographic distinctions:

Conclusions—ST-segment morphology variants associated with ER separates subjects with and without an increased risk of arrhythmic death in middle-aged subjects. Rapidly ascending ST segments after the J-point, the dominant ST pattern in healthy athletes, seems to be a benign variant of ER.

On the other hand, horizontal or descending ST segments signify an increased risk of death.

Friday, July 22, 2011

Quick reference card, asthma classification

The asthma classification is important to an understanding of the treatment guidelines. I’ve always found it difficult to keep straight, so this quick reference from the Paucis Verbis series at the Academic Life in Emergency Medicine blog should be useful.

CT pulmonary angiography and overdiagnosis of PE

A new study published in Archives of Internal Medicine looked at changing trends in diagnosis and outcomes for pulmonary embolism since introduction of CT pulmonary angiography:

We compared age-adjusted incidence, mortality, and treatment complications (in-hospital gastrointestinal tract or intracranial hemorrhage or secondary thrombocytopenia) of PE among US adults before (1993-1998) and after (1998-2006) CTPA was introduced. 

Results Pulmonary embolism incidence was unchanged before CTPA (P = .64) but increased substantially after CTPA (81% increase, from 62.1 to 112.3 per 100 000; P less than .001). Pulmonary embolism mortality decreased during both periods: more so before CTPA (8% reduction, from 13.4 to 12.3 per 100 000; P less than .001) than after (3% reduction, from 12.3 to 11.9 per 100 000; P = .02). Case fatality improved slightly before (8% decrease, from 13.2% to 12.1%; P = .02) and substantially after CTPA (36% decrease, from 12.1% to 7.8%; P less than .001). Meanwhile, CTPA was associated with an increase in presumed complications of anticoagulation for PE: before CTPA, the complication rate was stable (P = .24), but after it increased by 71% (from 3.1 to 5.3 per 100 000; P less than .001).

The authors note that these findings suggest overdiagnosis attributable to CTPA due to detection of isolated inconsequential filling defects. As the data show, this has significant clinical consequences. In that sense CTPA may be considered by some to be more sensitive than V/Q scanning. However, when long term clinical outcomes are used as the standard V/Q scanning has demonstrated superior sensitivity so long as a normal perfusion scan (note that’s normal, not “low prob”) is used to rule out PE.

Thursday, July 14, 2011

The changing profile of bacterial meningitis

From an NEJM study:

The incidence of meningitis changed by −31% (95% confidence interval [CI], −33 to −29) during the surveillance period, from 2.00 cases per 100,000 population (95% CI, 1.85 to 2.15) in 1998–1999 to 1.38 cases per 100,000 population (95% CI 1.27 to 1.50) in 2006–2007. The median age of patients increased from 30.3 years in 1998–1999 to 41.9 years in 2006–2007..

Of the 1670 cases reported during 2003–2007, S. pneumoniae was the predominant infective species (58.0%), followed by GBS (18.1%), N. meningitidis (13.9%), H. influenzae (6.7%), and L. monocytogenes (3.4%). An estimated 4100 cases and 500 deaths from bacterial meningitis occurred annually in the United States during 2003–2007.

Parenteral iron therapy

---is enjoying expanded use. Newer products are safer and no longer carry black box warnings.

Wednesday, July 13, 2011

Brugada pattern quick reference card

From the Paucis Verbis series at the Academic Life in Emergency Medicine blog.

ACLS and the use of antiarrhythmic agents

Here's a new systematic review published in the journal Resuscitation. The conclusions were in line with the current recommendations:

Amiodarone may be considered for those who have refractory VT/VF, defined as VT/VF not terminated by defibrillation, or VT/VF recurrence in out of hospital cardiac arrest or in-hospital cardiac arrest. There is inadequate evidence to support or refute the use of lidocaine and other antiarrythmic agents in the same settings.

Post thrombotic syndrome

Anticoagulation after VTE---indefinite or time limited?

Here's another review on the topic.

Points of interest:

Although thrombophilia testing predicts initial VTE it is not reliable for predicting recurrance.

Thrombophilia testing does not have a primary role in decision making regarding the duration of anticoagulation.

Thrombophilia testing has a limited role in individual circumstances and must take into account patient preference.

D-dimer testing after a course of anticoagulation is predictive of recurrent VTE and has a role in decision making about the duration of anticoagulation.

The duration of anticoagulation is largely a clinical decision, based on current guidelines and modified by the clinician's judgment in individual circumstances and the preference of an informed patient.

The recommendations in this review are similar to those of another review I linked here.

Tuesday, July 12, 2011

Diagnosis and treatment of VTE in pregnancy

A free full text review.

What's the appropriate cancer work up for patients presenting with unprovoked VTE?

A recently published evidence based review concluded:

Based on the available studies, we recommend that clinicians maintain a low threshold of suspicion for malignancy in patients who present with an unprovoked VTE. Moreover, patients with unprovoked VTE should provide a thorough medical history, undergo a physical examination, chest X-ray, and routine laboratory tests (including complete blood count, basic chemistries, liver function, and lactate dehydrogenase), and be up to date with age- and gender-specific cancer screening (Grade 1C). Additional diagnostic testing should be guided by any abnormal findings gleaned from the initial clinical or laboratory data.

Off-label use of recombinant factor VIIa---evidence based review of efficacy and safety

Despite the fact that recombinant factor VIIa is physiologically appealing for a variety of bleeding scenarios its approved indications are extremely limited. It is estimated that over 90% of its use is off -label. Here is a review of the evidence regarding VIIa for various off-label uses. The evidence of benefit in terms of hard clinical endpoints is scant, and in the off-label population the VTE risk is higher. Recommendations vary from guideline to guideline. The authors conclude:

In the absence of clearly supportive data, and with much data suggesting an increased risk of TAEs, we recommend that practicing hematologists exercise restraint in the use of rFVIIa in off-label settings. Until better quality and more statistically significant data regarding the use of rFVIIa in different off-label scenarios become available, we believe it is useful for professional organizations to develop conservative evidence-based guidelines for use of rFVIIa in off-label settings that should be updated frequently to reflect findings from new trials. We hope that patient safety will be appropriately guarded by this mechanism, while encouraging physicians to adapt their clinical practice to fresh evidence.

VTE in cancer patients

Here's a nice free full text review.

Thrombocytopenia in the ICU

Should you stop certain drugs? Modify your anticoagulant strategy? Delay important procedures? Transfuse platelets? This review may help.

Points of special interest:

Thrombocytopenia in the critically ill patient portends a worse outcome.

The most valuable clue as to the etiology of thrombocytopenia is often the time course of its development and recovery. Typical patterns are illustrated in the article.

Monday, July 11, 2011

Pocket mobile echocardiography---ready for prime time?

Should all hospitalists be carrying these things around? This Annals study suggests that more study is needed before they are ready for widespread use.

Chronic thromboembolic pulmonary hypertension

No longer an autopsy curiosity or an untreatable disease according to this review.

Claims of rapid response systems still unsupported

Yet another study, this one recently published in Chest, has failed to show an impact. RRTs are widely used in hospitals and widely claimed to be patient safety tools. Although the RRT may have a niche in your hospital or be a driver of education and process improvement the patient safety claim remains unfounded. Via Hospital Medicine Quick Hits.

Nesiritide---debate settled?

The long awaited nesiritide trial was just published in NEJM. Not really all that new, as it had been presented in part at American Heart last November. The long and the short: no difference in the big outcomes, with a modest improvement in dyspnea at the price of more hypotension. If nesiritide has a niche I don't know what it is. It's certainly not a front line agent for acute decompensated heart failure in hospitalized patients.

HT to Hospital Medicine Quick Hits.

Which hospitalized patients should receive GI bleeding prophylaxis with acid-suppressive medication?

According to this report acid-suppressive medications may be over utilized. The practice is widespread throughout hospitals. However, the evidence only supports use in critically ill patients.

Thursday, July 07, 2011

Outpatient management of PE---when is it safe?

A recently published study in the Lancet examined this question:

We undertook an open-label, randomised non-inferiority trial at 19 emergency departments in Switzerland, France, Belgium, and the USA. We randomly assigned patients with acute, symptomatic pulmonary embolism and a low risk of death (pulmonary embolism severity index risk classes I or II) with a computer-generated randomisation sequence (blocks of 2–4) in a 1:1 ratio to initial outpatient (ie, discharged from hospital greater than or equal to 24 h after randomisation) or inpatient treatment with subcutaneous enoxaparin (greater than or equal to 5 days)...

So in the outpatient arm the entirety of treatment was not really outpatient. Evidently patients remained in the ER or in an observation unit for up to 24 hours. More from the article: (0·6%) of 171 outpatients developed recurrent venous thromboembolism within 90 days compared with none of 168 inpatients (95% upper confidence limit [UCL] 2·7%; p=0·011). Only one (0·6%) patient in each treatment group died within 90 days (95% UCL 2·1%; p=0·005), and two (1·2%) of 171 outpatients and no inpatients had major bleeding within 14 days (95% UCL 3·6%; p=0·031). By 90 days, three (1·8%) outpatients but no inpatients had developed major bleeding (95% UCL 4·5%; p=0·086).

So while there was no difference in mortality there was a small increase in recurrent VTE and bleeding with outpatient treatment. Despite this the authors concluded that outpatient treatment was safe in selected low risk patients. How did they define low risk? Using the the pulmonary embolism severity index (PESI). I discussed the PESI previously here. As I cited in that post, an older study had suggested that the PESI could help select patients for outpatient treatment. The original study on the PESI is here.

Biomarkers and echocardiography are the traditional tools for acute risk assessment in PE, but clinical scores like the PESI are emerging as comparable means.

HT to Hospital Medicine Quick Hits.

Tuesday, July 05, 2011

ABCD 2---too easy to be true?

Clinicians have long relied on the ABCD 2 score to help determine which patients who present to the ER with TIA can be sent home for completion of their work up as an out patient. But the tool had never been prospectively validated. A new study in CMAJ tried to do just that. The result? If you use the traditional cut off of a score of 5 the sensitivity is lousy. If you use AHA's recommended score of 2 the sensitivity improves considerably but the specificity is poor.

A related Medscape piece offers some insightful comments from one of the study authors and new perspectives on today's stroke care:

The investigators found that an ABCD2 score of more than 5 had low sensitivity (31.6%; 95% confidence interval [CI], 19.1% – 47.5%) for predicting subsequent stroke at 7 days. For predicting stroke at 90 days, its sensitivity was 29.2% (95% CI, 19.6% – 41.2%). "These sensitivities are too low to be clinically acceptable," Dr. Perry said...
"The proposed threshold by the American Heart Association, which is a score greater than 2 to indicate high risk, was very sensitive; however, it classified all but a few patients as high risk, so it is not very discriminating for early stroke," Dr. Perry noted.

Which means you might as well admit just about everybody, if not to the hospital to a stroke obs unit, if you have one, or hold them in the ER long enough to do more extensive imaging, more than just a CT scan.

How would the score perform if integrated with aggressive imaging in the ER? That's a question for further study.

Friday, July 01, 2011

Serum potassium levels after cardiac arrest

Here's a really interesting study that looked at serum potassium levels after cardiac arrest:

The mean potassium level was 3.9±0.9mmol/l and thus within the reference range of 3.5–5.0mmol/l, but the overall prevalence of hypokalaemia was high (31.0%). Moderate rather than severe hypokalaemia was typically observed..
Among those six patients with extreme hypokalaemia defined as a potassium levels below the 2.5 percentile, two adult females were identified to suffer from previously untreated body scheme disorder with furosemide abuse (potassium 1.1 and 1.4mmol/l). Another patient (potassium 2.1mmol/l) suffered from poorly controlled bulimia nervosa and acute diarrhoea due to GI infection and one (potassium 2.4mmol/l) from untreated bulimic anorexia...
In contrast to moderately reduced potassium which is a frequent finding in adult patients at the time of admission for non-traumatic cardiac arrest, severe hypokalaemia is uncommon. The high prevalence of patients with body dysmorphophobic eating disorders in this group underscores accidental self-induced hypokalaemia may evolve as an important differential diagnosis in cardiac arrest in young female patients.

Mild to moderate hypokalemia after cardiac arrest may be redistributional, due either to endogenous catecholamines associated with the cardiac event or to administered epinephrine and therefore may not reflect pre-arrest potassium levels. In this study severe hypokalemia was associated with eating disorders and extreme dieting.

That, you may recall, is what caused Terri Schiavo's cardiac arrest:

Upon admission to the hospital, her serum potassium level was noted to be very low, at 2.0 mEq/L...
Her medical chart contained a note that "she apparently has been trying to keep her weight down with dieting by herself, drinking liquids most of the time during the day and drinking about 10–15 glasses of iced tea”...
Terri's husband, Michael, later filed and won a malpractice suit against her obstetrician, Dr. Stephen Igel, who was treating her for infertility, on the basis that he failed to diagnose bulimia as the cause of her infertility.

Postmortem examination, including a molecular autopsy, found no evidence of structural heart disease or channelopathy.