Saturday, April 29, 2017

The Coombs test: some things you need to know


A nice free full text review in the Archives of Pathology and Laboratory Medicine.

Friday, April 28, 2017

Review of carcinoid heart disease


The full text of this review is available only by subscription, but the audio summary is open access.

Here are a few key points:

Carcinoid tumors (CT) tend to grow slowly and remain asymptomatic for long periods. Carcinoid syndrome (CS), the clinical state resulting from release of mediators by the tumor, generally does not occur until it metastasizes to the liver, though there are exceptions to this rule. CS consists of vasomotor disturbances, flushing, bronchospasm and diarrhea and is primarily mediated by serotonin although other mediators including kinins, histamine and prostaglandins are involved.

Carcinoid heart disease (CHD) is a valvulopathy (most frequently the tricuspid, followed in order of frequency by the pulmonic and then the left sided valves) caused by an inflammatory and fibroproliferative response of valvular endocardium to the circulating mediators, most notably serotonin. Regurgitation is the primary lesion affecting the valves although stenosis can occur to a lesser degree.

It is estimated that 50% of patients with CS go on to develop CHD though that number may be decreasing with improvements in recognition and treatment of CS. Once CHD develops it tends to progress rapidly and worsens the prognosis of patients with CS.

Transcatheter embolization and surgical debulking of liver metastases are indicated in some patients but become less viable options if hepatic congestion has developed due to the risk of acute liver failure and bleeding.

Valve replacement may improve the outlook for selected patients.

Chronic calcium blocker use and reduced mortality in sepsis


From a recent paper:

Abstract

Objectives: Experimental studies suggest that calcium channel blockers can improve sepsis outcome. The aim of this study was to determine the association between prior use of calcium channel blockers and the outcome of patients admitted to the ICU with sepsis.

Design: A prospective observational study.

Setting: The ICUs of two tertiary care hospitals in the Netherlands.

Patients: In total, 1,060 consecutive patients admitted with sepsis were analyzed, 18.6% of whom used calcium channel blockers.

Interventions: None.

Measurements and Main Results: Considering large baseline differences between calcium channel blocker users and nonusers, a propensity score matched cohort was constructed to account for differential likelihoods of receiving calcium channel blockers. Fifteen plasma biomarkers providing insight in key host responses implicated in sepsis pathogenesis were measured during the first 4 days after admission. Severity of illness over the first 24 hours, sites of infection and causative pathogens were similar in both groups. Prior use of calcium channel blockers was associated with improved 30-day survival in the propensity-matched cohort (20.2% vs 32.9% in non-calcium channel blockers users; p = 0.009) and in multivariate analysis (odds ratio, 0.48; 95% CI, 0.31–0.74; p = 0.0007). Prior calcium channel blocker use was not associated with changes in the plasma levels of host biomarkers indicative of activation of the cytokine network, the vascular endothelium and the coagulation system, with the exception of antithrombin levels, which were less decreased in calcium channel blocker users.

In the discussion section the authors mention a possible mechanism:

Here, we show a significantly reduced mortality in ICU patients who were on chronic CCB treatment before development of sepsis. The association between prior CCB use and reduced sepsis mortality was consistent in sensitivity and subgroup analyses. The mechanism by which chronic CCB use may influence sepsis outcome was not revealed by sequential measurements of host response biomarkers reflecting activation of the cytokine network, the vascular endothelium or the coagulation system, and rather may involve partial prevention of cellular toxicity related to sustained elevations in intracellular Ca2+ levels.


Update on the clinical and pathologic aspects of ANCA diseases


Friday, March 24, 2017

Vancomycin in combination with zosyn increased the risk of AKI



Increased AKI with concomitant vancomycin and piperacillin/tazobactam should be considered when determining beta-lactam therapy.

Thursday, March 23, 2017

Type of atrial fibrillation and stroke risk


From a recent paper:

Background—Whether the pattern of atrial fibrillation (AF) modifies the risk/benefit of anticoagulation is controversial…

Conclusions—In ENGAGE AF-TIMI 48 trial, patients with paroxysmal AF suffered fewer thromboembolic events and deaths compared with those with persistent and permanent AF.

Wednesday, March 22, 2017

Hypotension due to IV acetaminophen


From a recent paper published in Critical Care Medicine:

Objectives: We sought to assess the incidence of acetaminophen-induced hypotension. Our secondary objectives were to describe systemic hemodynamic changes and factors associated with this complication.

Design: Prospective observational study.

Setting: Three ICUs.

Patients: Adult patients requiring IV acetaminophen infusion. Arterial pressure was monitored via an arterial catheter for 3 hours. Hypotension was defined as a decrease in the mean arterial pressure of greater than or equal to 15% compared with the baseline…

Conclusions: Half of the patients who received IV injections of acetaminophen developed hypotension, and up to one third of the observed episodes necessitated therapeutic intervention. Adequately powered randomized studies are needed to confirm our findings, provide an accurate estimation of the consequences of acetaminophen-induced hypotension, and assess the pathophysiologic mechanisms involved.

Tuesday, March 21, 2017

Treatment decisions for patients with a first seizure


Here is a guideline synopsis published in JAMA. From the article:


Major recommendations Whether to initiate immediate antiepileptic drug (AED) treatment after a first seizure should be based on individualized assessments that weigh the risk of recurrence against the adverse effects of AED therapy, a consideration of the preferences of an educated patient, and the advice that immediate treatment will not improve the long-term prognosis for seizure remission but will reduce the risk of seizures over the subsequent 2 years…


The new guideline emphasizes that clinicians should weigh the individualized risk of seizure recurrence against the adverse effects of AEDs and consider the preferences of patients. For instance, the risk of seizure recurrence in a patient with normal electroencephalogram and brain magnetic resonance imaging results is relatively low at approximately 25% over the next 2 years.8 While some patients may accept the 25% risk, others may consider it too high. Regardless, patients should be advised that immediate treatment may not improve the long-term prognosis for seizure remission but will reduce seizure risk over the next 2 years. Despite avoiding explicit “to treat or not to treat” recommendations, most of the guideline recommendations conform to current clinical practices. States vary widely in driver licensing requirements for patients with epilepsy (https://www.epilepsy.com/driving-laws), as do requirements for physicians to notify state authorities, complicating the provision of accurate instructions to patients.