Physician Reviews of Hospital Medicine-Related Research

In This Edition

Literature At A Glance

A guide to this month’s studies

1. BNP-driven fluid management to improve ventilator weaning
2. Examining 30-day readmission patterns to reduce repeat hospitalizations
3. Impact of hospitalists’ workload on patient safety, care
4. Permanent atrial fibrillation is best controlled by diltiazem
5. Low-dose thrombolysis effective for pulmonary embolism
6. High mortality rate seen in surgical patients requiring CPR
7. ED visits common for acute-care patients post-discharge
8. Restrictive transfusion strategies effective for upper GI bleeding
9. Need for non-ICU acid suppression may be predictable
10. Recommended changes for adult immunizations

BNP-Driven Fluid Management Improves Ventilator Weaning

Clinical question: Does fluid management guided by daily plasma natriuretic peptide-driven (BNP) levels in mechanically ventilated patients improve weaning outcomes compared with usual therapy dictated by clinical acumen?

Background: Ventilator weaning contributes at least 40% of the total duration of mechanical ventilation; strategies aimed at optimizing this process could provide substantial benefit. Previous studies have demonstrated that BNP levels prior to ventilator weaning independently predict weaning failure. No current objective practical guide to fluid management during ventilator weaning exists.

Study design: Randomized controlled trial.

Setting: Multiple international centers.

Synopsis: In a multicenter randomized controlled trial, 304 patients who met specific inclusion and exclusion criteria were randomized to either a BNP-driven or physician-guided strategy for fluid management during ventilator weaning. Patients with renal failure were excluded because of the influence of renal function on BNP levels.

All patients in both groups were ventilated with an automatic computer-driven weaning system to standardize the weaning process. In the BNP-driven group, diuretic use was higher, resulting in a more negative fluid balance and significantly shorter time to successful extubation (58.6 hours vs. 42.2 hours, P=0.03). The effect on weaning time was strongest in patients with left ventricular systolic dysfunction, whereas those with COPD seemed less likely to benefit. The two groups did not differ in baseline characteristics, length of stay, mortality, or development of adverse outcomes of renal failure, shock, or electrolyte disturbances.

Bottom line: Compared with physician-guided fluid management, a BNP-driven fluid management protocol decreased duration of ventilator weaning without significant differences in adverse events, mortality rate, or length of stay between the two groups.

Citation: Dessap AM, Roche-Campo F, Kouatchet A, et al. Natriuretic peptide-driven fluid management during ventilator weaning. Am J Respir Crit Care Med. 2012;186(12):1256-1263.

30-Day Readmission Patterns for MI, Heart Failure, Pneumonia

Clinical question: Do patterns exist among patients readmitted within 30 days of discharge for acute myocardial infarction (AMI), heart failure, or pneumonia that could provide insight for improving strategies aimed at reducing readmission rates?

Background: Examining readmission timing, diagnoses, and patient demographics might provide information to better guide post-discharge programs aimed at reducing overall readmissions.

Study design: Retrospective review of Centers for Medicare & Medicaid Services (CMS) data.

Setting: Acute-care hospitals.

Synopsis: Using CMS hospitalization data for principal diagnoses of AMI, heart failure, or pneumonia from 2007 through 2009, the authors examined the percentage of 30-day readmissions occurring on each day after discharge; the most common readmission diagnoses; the median time to readmission for common readmission diagnoses; and the relationship between patient demographic characteristics, readmission diagnoses, and timing. They found total readmission rates of 24.8% for heart failure, 19.9% for AMI, and 18.3% for pneumonia. Approximately two-thirds of 30-day readmissions occurred within the first 15 days after discharge for each cohort. Neither readmission diagnoses nor timing varied by patient age, sex, or race.

Although the majority of readmissions do occur soon after discharge, it is important to note that about one-third of all readmissions occur 16 to 30 days after discharge. There also was a diverse spectrum of readmission diagnoses that were not associated with patient demographic characteristics. These findings suggest that current post-discharge strategies aimed at specific diseases or time periods might only address a fraction of the patients at risk for readmission.