Controversy exists regarding the routine use of positive end-expiratory pressure (PEEP) in mechanically ventilated patients. We hypothesized that nonhypoxic patients receiving 5-cm H2 O PEEP would have improved shunt and PaO2 /FIO2 ratios (P/F), without an increased dead space to tidal volume ratio (VD/VT) versus patients receiving no PEEP. Forty-four trauma patients were randomized to receive 5-cm H2 O PEEP (PEEP) or 0-cm H2 O PEEP (ZEEP). Shunt VD/VT and P/F were measured at 0, 12, 24, 36, and 48 hours after intubation and after extubation. PEEP and ZEEP comparisons used Student's t test and the General Linear Models procedure. Shunt was significantly increased at t = 0 and at extubation in the PEEP group. At extubation, the PEEP group demonstrated significantly higher VD/VT and poorer P/F ratios. After correction for baseline values, no statistically significant differences were noted in spite of a trend toward worsening pulmonary function in all measured parameters. These results suggest that routine use of 5-cm H2 O PEEP in mechanically ventilated trauma patients is not necessary.
From the Department of Surgery, University of New Mexico, Albuquerque, New Mexico (A.R.V.) and the Department of Surgery, University of Florida Health Science Center/Jacksonville, Jacksonville, Florida (F.W.C.).
Presented at the Fifty-Fourth Annual Session of the American Association for the Surgery of Trauma, September 29-October 1, 1994, San Diego, California.
Address for reprints: Frederick W. Clevenger, MD, FACS, Chief, Division of Trauma and Critical Care, Department of Surgery, University of Florida HSC/Jackonville, 653-2 West Eighth St., Jacksonville, FL 32209.