ITL: Physician Reviews of HM-Relevant Research
In This Edition
Literature At A Glance
A guide to this month’s studies
- Online calculator helps prevent post-op respiratory failure
- New drug for long-term treatment of PE
- Benefits of triple therapy for COPD
- Knee-length compression stockings as good as thigh-length for PTS
- Video monitoring improves hand hygiene
- Asymptomatic bacteriuria often misdiagnosed as UTI
- CT accurate for lower GI bleeding diagnosis
- Switch from albuterol to lavalbuterol to reduce tachycardia not recommended
Preoperative Risk Calculator Can Help Predict Postoperative Respiratory Failure
Clinical question: Can preoperative factors identify patients at risk for postoperative respiratory failure (PRF)?
Background: PRF—when a patient requires mechanical ventilation >48 hours after surgery or needs unplanned intubation within 30 days of surgery—is associated with high mortality, with 30-day mortality rates of 26%.
Study design: Analysis of multicenter, prospective databases of the American College of Surgeons National Surgical Quality Improvement Program (NSQIP).
Setting: Analysis of NSQIP data from 2007 (training set) and 2008 (validation set).
Synopsis: PRF was seen in 3.1% of patients in the 2007 data set and 2.6% in the 2008 data set. Those with PRF had significantly higher mortality rates than those without PRF (25.62% vs. 0.98%; P<0.0001). Preoperative risk factors associated with significantly increased risk of PRF were American Society of Anesthesiologists’ class, functional status, emergent nature of procedure, type of surgery, and preoperative sepsis.
The 2007 data set was used to develop the model, and the 2008 data set was used as a validation set. The selected risk model showed similar results in both sets with a c-statistic of 0.91 in the training set and 0.90 in the validation set. This selected model was then used to develop an interactive calculator predicting PRF (available at www.surgicalriskcalculator.com/prf-risk-calculator).
Bottom line: The PRF risk calculator can identify patients at high risk for PRF, which can aid in tailoring preventive strategies for patients prior to surgery.
Citation: Gupta H, Gupta PK, Fang X, et al. Development and validation of a risk calculator predicting postoperative respiratory failure. Chest. 2011;140:1207-1215.
New Drug for Treatment of Acute Symptomatic Pulmonary Embolism
Clinical question: Is the incidence of recurrent venous thromboembolism (VTE) or bleeding with use of idrabiotaparinux comparable to warfarin for treatment of acute symptomatic pulmonary embolism (PE)?
Background: Warfarin is an effective treatment for PE; however, maintenance of effective and safe levels of anticoagulation is difficult to achieve. A straightforward treatment option would be an attractive alternative. Idrabiotaparinux, a factor Xa inhibitor bound with a biotin moiety, is a weekly subcutaneous injection proposed as an alternative to warfarin for treatment of PE.
Study design: Industry-sponsored double-blind, randomized controlled trial.
Setting: 291 centers in 37 countries.
Synopsis: A group of 3,202 patients aged 18 to 96 years were randomly assigned to receive enoxaparin, followed by idrabiotaparinux or enoxaparin, then overlapped and followed by warfarin for three or six months. The incidence of recurrent VTE (including fatal and nonfatal PE or deep vein thrombosis) did not differ between the two treatment arms.
Of the 1,599 patients treated with idrabiotaparinux, 48 (3%) had a recurrence; of the 1,603 treated with warfarin, 97 (6%) had a recurrence (odds ratio, 0.49). The rate of clinically relevant bleeding was also similar, with 72 (5%) in the idrabiotaparinux group versus 106 (7%) in the warfarin group. Much like warfarin, idrabiotaparinux requires bridging therapy with initial low-molecular-weight heparin.
Bottom line: Use of enoxaparin followed by weekly subcutaneous injection of idrabiotaparinux was as effective as enoxaparin followed by warfarin for preventing recurrent VTE, and may provide a suitable option for treatment of acute symptomatic PE.
