In This Edition
Literature At A Glance
A guide to this month’s studies
- Initial trophic feedings effective for patients with acute lung injury
- IM vs. IV benzodiazepines in status epilepticus
- CDI risk following antibiotic cessation
- Acid suppression associated with increased complications in CDI patients
- Perioperative statins and cardiac events in surgical patients
- Enoxaparin vs. unfractionated heparin during PCI
- Optimal serum potassium levels for AMI patients
- PPIs superior to H2-blockers for lowering UGI bleeding following ACS and STEMI
Initial Lower-Volume Enteral Feeding Better Tolerated, but Has No Mortality Benefit
Clinical question: In mechanically ventilated patients with acute lung injury, do initial lower-volume enteral feedings (trophic feedings) improve clinical outcomes when compared with full enteral feedings?
Background: Malnutrition in critically ill patients is associated with poor outcomes, but conflicting data exist regarding the best timing, amount, and formulation of enteral nutrition to initiate. Initiation of lower-volume enteral feeding with periodic assessment of gastric residual volume is common practice, but the effects of this practice are unknown.
Study design: Multicenter randomized controlled open-label study.
Setting: Forty-four hospitals in the National Heart, Lung, and Blood Institute (NHLBI) Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network.
Synopsis: One thousand patients with acute lung injury receiving mechanical ventilation for longer than 72 hours were randomized using a Web-based system to receive either trophic or full enteric feedings for the first six days of mechanical ventilation. After the sixth day, a full enteric feeding protocol was used in all patients. All analyses were by intention-to-treat.
There was no significant difference between the trophic and full enteral feeding groups with regard to the primary outcome of ventilator-free days through Day 28 (14.9% vs. 15.0%, P=0.89). There were also no significant differences between groups in secondary outcomes, which included 60-day mortality, ICU-free days, organ-failure-free days, or the incidence of new infections. However, gastrointestinal intolerances occurred less often in the trophic feeding group, and these patients received fewer anti-diarrheal and prokinetic agents. The full feeding group gained 2.1 liters of fluid by Day 7, but this fluid gain did not cause significant differences in measures of circulatory or pulmonary physiology.
Limitations include open-label study design and inclusion of only critically ill adult medical patients with acute lung injury.
Bottom line: Initial lower-volume tube feedings in mechanically ventilated patients with acute lung injury did not improve clinical outcomes compared with full enteral feedings, but they were associated with fewer instances of gastrointestinal intolerance.
Citation: National Heart, Lung, and Blood Institute Acute Respiratory Distress Syndrome (ARDS) Clinical Trials Network. Initial trophic vs full enteral feeding in patients with acute lung injury: the EDEN randomized trial. JAMA. 2012;307:795-803.
Intramuscular Benzodiazepines as Good as IV Benzodiazepines in Status Epilepticus
Clinical question: Is intramuscular (IM) midazolam noninferior to intravenous lorazepam in patients in status epilepticus?
Background: Studies have shown that IV benzodiazepines, particularly lorazepam, are effective for patients in status epilepticus. Studies have not evaluated IM benzodiazepines. However, many emergency medical service (EMS) agencies use IM midazolam because IM administration is easier than IV administration, and midazolam has a longer nonrefrigerated shelf life than lorazepam does.
Study design: Randomized, double-blinded clinical trial.
Setting: Thirty-three EMS agencies across the United States.
Synopsis: Based on the 893 adults and children in status epilepticus included in this double-blind study, the researchers found IM midazolam to be noninferior to, and in fact superior to, IV lorazepam for treating seizures prior to arrival at EDs. Specifically, they found 10% more (95% CI 4.0% to 16.1%; P<0.001 for noninferiority and P<0.001 for superiority) seizure-free patients arriving at EDs when IM midazolam was administered. Seizures ceased in patients given IM midazolam in less time on average than it took for paramedics to administer IV lorazepam.