April 2008

Spring Bulletin Online Now
The Spring edition of our Section Bulletin is online now, so visit the SECTION WEB SITE to read great articles on gaining the respect of other health care professionals, pulse oximetry, and ventilator-associated pneumonia.

Proning Needs More Study
A new study out of Tunisia suggests more research is needed to establish the benefits of proning in ARDS. Researchers reviewed 5 trials involving 1,372 patients. An additional trial that assessed the effect of proning on ventilator-associated pneumonia (VAP) was included in the analysis as well. The combined results showed no effect of prone position on mortality. But the PaO2/FiO2 ratio increased significantly with proning, and proning was associated with a non-significant 23% reduction in the odds of VAP, with no increase in major adverse airway complications. Since the studies were all heterogeneous in nature, however, the authors believe “an adequately sized study optimizing the duration of proning and ventilation strategy is warranted to enable definitive conclusions to be drawn.” The report appeared in the March 19 Epub edition of Intensive Care Medicine. READ ABSTRACT

Study Supports Larger VTs
Could the application of larger tidal volumes (VT) than currently used in clinical situations help stabilize lung function in lung injured patients? Boston researchers publishing in the March 13 Epub edition of the Journal of Applied Physiology believe the answer may be yes. They compared four modes of ventilation in mice: original variable ventilation (VVO) in which VT and breathing rate are varied from breath to breath; conventional ventilation (CV); CV with periodic large breaths (CVLB); and a new VV mode (VVN) with an optimized distribution of VT to maximize recruitment. Both normal and injured mice showed regional lung collapse with increased airway pressures and poor oxygenation during both CV and VVO, whereas ventilation with CVLB and VVN resulted in a stable dynamic equilibrium with significantly improved respiratory mechanics and oxygenation. VVN, however, provided a consistently better physiological response. In injured mice, both VVO and VVN minimized the IL-1 beta-related inflammatory response when compared to CV. READ ABSTRACT

Noninvasive Ventilation May Be Acceptable Option for Heart Failure Patients
Researchers from the Cleveland Clinic find noninvasive ventilation does not increase mortality in patients with acute decompensated heart failure and may be considered a reasonable treatment option. The study involved 37,372 patients, 2,430 of whom received some form of ventilation. The investigators compared patients in four groups: no ventilation, NIV success, NIV failure (defined as requiring intubation), and endotracheal intubation (ETI). Among patients who received ventilation, 69.5% were deemed NIV success, 3.0% were NIV failures, and 27.6% required ETI. The lowest O2 saturation was seen in the NIV failure group, and patients requiring ETI were more likely to receive vasoactive medications than those in the NIV success group. The only difference between the NIV failures and the ETI patients was that the NIV failures were more likely to receive vasodilators. In-hospital mortality was 7.9% in the NIV success group, 13.9% in the NIV failure group, and 15.4% in the ETI group. The study appears in this month’s Academic Emergency Medicine. READ ABSTRACT

Acute Asthma Improves with NPPV
Japanese researchers find noninvasive positive pressure ventilation (NPPV) may improve an acute asthma attack without the use of bronchodilators. They arrived at that conclusion after studying the use of high pressure and low pressure NPPV in patients with mild to moderate acute asthma. Patients in the high pressure group received a fixed expiratory positive airway pressure of 6 cm H2O and an inspiratory positive airway pressure of 8 cm H2O. Those in the low pressure group received 4 cm H2O and 6 cm H2O, respectively. Patients in the high pressure group saw significant improvement in mean FEV1. Both groups experienced improvements in modified Borg scale scores and on physical examination findings. The authors write, “We conclude that higher inflation pressure on NPPV led to clinical improvement in patients with acute asthma attacks of mild to moderate severity.” The research was published in the March 17 Epub edition of Internal Medicine. READ ABSTRACT