Thomas W. Emmett

Pharmacologic prophylaxis for acute mountain sickness: a systematic shortcut review.

STUDY OBJECTIVE Multiple studies have explored pharmacologic interventions to prevent acute mountain sickness. A systematic review of this subject published in 2000 found that both acetazolamide and dexamethasone were effective. Since 2000, a number of other agents have been reported to be beneficial. This EBEM review evaluates the most current evidence on this topic. METHODS We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, SPORTDiscus, Emergency Medical Abstracts, and ClinicalTrials.gov from 2000 to July 2011. Only randomized placebo-controlled trials with an N greater than or equal to 50 and systematic reviews were reviewed. Standard criteria for assessing trial quality were independently assessed by 2 authors. RESULTS Seven hundred eighty-six citations were retrieved, of which 105 were reviewed in their entirety. Eleven randomized controlled trials and 1 systematic review appeared to meet inclusion criteria; however, 4 randomized controlled trials were excluded for high risk of bias. The remaining 7 randomized controlled trials investigated antioxidants, magnesium, sumatriptan, gabapentin, acetazolamide, and Ginkgo biloba. No trials studying dexamethasone met our criteria. Acetazolamide was associated with a reduction in acute mountain sickness symptoms, with a number needed to treat ranging from 8 to 3 among 3 trials and at doses ranging from 250 to 750 mg daily. Sumatriptan showed benefit in 1 trial (number needed to treat=4), as did gabapentin (number needed to treat=6). Antioxidants, magnesium, and G biloba were not efficacious. Reported adverse events included somnolence with gabapentin and paresthesias with acetazolamide. The systematic review affirmed our results but did not capture trials studying antioxidants, magnesium, sumatriptan, or gabapentin. CONCLUSION Acetazolamide is effective for the prevention of acute mountain sickness but may be associated with paresthesias. Sumatriptan and gabapentin are beneficial but require further study.

Findings From 12-lead Electrocardiography That Predict Circulatory Shock From Pulmonary Embolism: Systematic Review and Meta-analysis

OBJECTIVES Treatment guidelines for acute pulmonary embolism (PE) recommend risk stratifying patients to assess PE severity, as those at higher risk should be considered for therapy in addition to standard anticoagulation to prevent right ventricular (RV) failure, which can cause hemodynamic collapse. The hypothesis was that 12-lead electrocardiography (ECG) can aid in this determination. The objective of this study was to measure the prognostic value of specific ECG findings (the Daniel score, which includes heart rate > 100 beats/min, presence of the S1Q3T3 pattern, incomplete and complete right bundle branch block [RBBB], and T-wave inversion in leads V1-V4, plus ST elevation in lead aVR and atrial fibrillation suggestive of RV strain from acute pulmonary hypertension), in patients with acute PE. METHODS Studies were identified by a structured search of MEDLINE, PubMed, EMBASE, the Cochrane library, Google Scholar, Scopus, and bibliographies in October 2014. Case reports, non-English papers, and those that lacked either patient outcomes or ECG findings were excluded. Papers with evidence of a predefined reference standard for PE and the results of 12-lead ECG, stratified by outcome (hemodynamic collapse, defined as circulatory shock requiring vasopressors or mechanical ventilation, or in hospital or death within 30 days) were included. Papers were assessed for selection and publication bias. The authors also assessed heterogeneity (I(2) ) and calculated the odds ratios (OR) for each ECG sign from the random effects model if I(2) > 24% and fixed effects if I(2) < 25%. Funnel plots were used to examine for publication bias. RESULTS Forty-five full-length studies of 8,209 patients were analyzed. The most frequent ECG signs found in patients with acute PE were tachycardia (38%), T-wave inversion in lead V1 (38%), and ST elevation in lead aVR (36%). Ten studies with 3,007 patients were included for full analysis. Six ECG findings (heart rate > 100 beats/min, S1Q3T3, complete RBBB, inverted T waves in V1-V4, ST elevation in aVR, and atrial fibrillation) had likelihood and ORs with lower-limit 95% confidence intervals above unity, suggesting them to be significant predictors of hemodynamic collapse and 30-day mortality. OR data showed no evidence of publication bias, but the proportions of patients with hemodynamic collapse or death and S1Q3T3 and RBBB tended to be higher in smaller studies. Patients who were outcome-negative had a significantly lower mean ± SD Daniel score (2.6 ± 1.5) than patients with hemodynamic collapse (5.9 ± 3.9; p = 0.039, ANOVA with Dunnetts post hoc), but not patients with all-cause 30-day mortality (4.9 ± 3.3; p = 0.12). CONCLUSIONS This systematic review and meta-analysis revealed 10 studies, including 3,007 patients with acute PE, that demonstrate that six findings of RV strain on 12-lead ECG (heart rate > 100 beats/min, S1Q3T3, complete RBBB, inverted T waves in V1-V4, ST elevation in aVR, and atrial fibrillation) are associated with increased risk of circulatory shock and death.

Hospital Readmissions in Patients with Cirrhosis: A Systematic Review

BACKGROUND Hospital readmission is a significant problem for patients with complex chronic illnesses such as liver cirrhosis. PURPOSE We aimed to describe the range of readmission risk in patients with cirrhosis and the impact of the model for end-stage liver disease (MELD) score. DATA SOURCES We conducted a systematic review of studies identified in Ovid MEDLINE, PubMed, EMBASE, CINAHL, the Cochrane Library, Scopus, Google Scholar, and ClinicalTrials.gov from 2000 to May 2017. STUDY SELECTION We examined studies that reported early readmissions (up to 90 days) in patients with cirrhosis. Studies were excluded if they did not examine the association between readmission and at least 1 variable or intervention. DATA EXTRACTION Two reviewers independently extracted data on study design, setting, population, interventions, comparisons, and detailed information on readmissions. DATA SYNTHESIS Of the 1363 records reviewed, 26 studies met the inclusion and exclusion criteria. Of these studies, 21 were retrospective, and there was significant variation in the inclusion and exclusion criteria. The pooled estimate of 30-day readmissions was 26%(95% confidence interval [CI], 22%–30%). Few studies examined readmission preventability or the relationship between readmissions and social determinants of health. Reasons for readmission were highly variable. An increased MELD score was associated with readmissions in most studies. Readmission was associated with increased mortality. CONCLUSION Hospital readmissions frequently occur in patients with cirrhosis and are associated with liver disease severity. The impact of functional and social factors on readmissions is unclear.