Noninvasive Ventilation More Effective, Safer for Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD)
Clinical question: What are the patterns in use of noninvasive ventilation (NIV) and invasive mechanical ventilation (IMV) in patients with AECOPD, and which method produces better outcomes?
Background: Multiple randomized controlled trials and meta-analyses have suggested a mortality benefit with NIV compared to standard medical care in AECOPD. However, little evidence exists on head-to-head comparisons of NIV and IMV.
Study design: Retrospective cohort study.
Setting: Non-federal, short-term, general, and other specialty hospitals nationwide.
Synopsis: A sample of 67,651 ED visits for AECOPD with acute respiratory failure was analyzed from the National Emergency Department Sample (NEDS) database between 2006 and 2008. The study found that NIV use increased to 16% in 2008 from 14% in 2006. Use varied widely between hospitals and was more utilized in higher-case-volume, nonmetropolitan, and Northeastern hospitals. Compared with IMV, NIV was associated with 46% lower inpatient mortality (risk ratio 0.54, 95% confidence interval [CI] 0.50-0.59), shortened hospital length of stay (-3.2 days, 95% CI -3.4 to -2.9), lower hospital charges (-$35,012, 95% CI -$36,848 to -$33,176), and lower risk of iatrogenic pneumothorax (0.05% vs. 0.5%, P<0.001). Causality could not be established given the observational study design.
Bottom line: NIV is associated with better outcomes than IMV in the management of AECOPD, and might be underutilized.
Citation: Tsai CL, Lee WY, Delclos GL, Hanania NA, Camargo CA Jr. Comparative effectiveness of noninvasive ventilation vs. invasive mechanical ventilation in chronic obstructive pulmonary disease patients with acute respiratory failure. J Hosp Med. 2013;8(4):165-172.
Synthetic Cannabinoid Use May Cause Acute Kidney Injury
Clinical question: Are synthetic cannabinoids associated with acute kidney injury (AKI)?
Background: Synthetic cannabinoids are designer drugs of abuse with a growing popularity in the U.S.
Study design: Retrospective case series.
Setting: Hospitals in Wyoming, Oklahoma, Rhode Island, New York, Kansas, and Oregon.
Synopsis: The Centers for Disease Control and Prevention (CDC) issued an alert when 16 cases of unexplained AKI after exposure to synthetic cannabinoids were reported between March and December 2012. Synthetic cannabinoid use is associated with neurologic, sympathomimetic, and cardiovascular toxicity; however, this is the first case series reporting renal toxicity. The 16 patients included 15 males and one female, aged 15-33 years, with no pre-existing renal disease or nephrotoxic medication consumption. All used synthetic cannabinoids within hours to days before developing nausea, vomiting, abdominal, and flank and/or back pain.
Creatinine peaked one to six days after symptom onset. Five patients required hemodialysis, and all 16 recovered. There was no finding specific for all cases on ultrasound and/or biopsy. Toxicologic analysis of specimens was possible in seven cases and revealed a previously unreported fluorinated synthetic cannabinoid compound XLR-11 in all clinical specimens of patients who used the drug within two days of being tested.
Overall, the analysis did not reveal any single compound or brand that could explain all cases.
Bottom line: Clinicians should be aware of the potential for renal or other toxicities in users of synthetic cannabinoid products and should ask about their use in cases of unexplained AKI.
Citation: Murphy TD, Weidenbach KN, Van Houten C, et al. Centers for Disease Control and Prevention. Acute kidney injury associated with synthetic cannabinoid use—multiple states, 2012. MMWR Morb Mortal Wkly Rep. 2013;62(6):93-98.
Dabigatran versus Warfarin in Extended VTE Treatment
Clinical question: Is dabigatran suitable for extended treatment VTE?
Background: In contrast to warfarin (Coumadin), dabigatran (Pradaxa) is given in a fixed dose and does not require frequent laboratory monitoring. Dabigatran has been shown to be noninferior to warfarin in the initial six-month treatment of VTE.