Skip Navigation LinksHome > July 2014 - Volume 77 - Issue 1 > “Permissive hypoventilation” in a swine model of hemorrhagic...
Journal of Trauma and Acute Care Surgery:
doi: 10.1097/TA.0000000000000278
EAST 2014 Plenary Papers

“Permissive hypoventilation” in a swine model of hemorrhagic shock

Taghavi, Sharven MD, MPH; Jayarajan, Senthil N. MD; Ferrer, Lucas M. MD; Vora, Halley MD; McKee, Conor; Milner, Richard E.; Gaughan, John P. PhD; Dujon, Jay MD; Sjoholm, Lars O. MD; Pathak, Abhijit MD; Rappold, Joseph F. MD; Santora, Thomas A. MD; Houser, Steven R. PhD; Goldberg, Amy J. MD

Editor's Choice
Collapse Box

Abstract

BACKGROUND

Many penetrating trauma patients in severe hemorrhagic shock receive positive pressure ventilation (PPV) upon transport to definitive care, either by intubation (INT) or bag-valve mask (BVM). Using a swine hemorrhagic shock model that simulates penetrating trauma, we proposed that severely injured patients may have better outcomes with “permissive hypoventilation,” where manual breaths are not given and oxygen is administrated passively via face mask (FM). We hypothesized that PPV has harmful physiologic effects in severe low-flow states and that permissive hypoventilation would result in better outcomes.

METHODS

The carotid arteries of Yorkshire pigs were cannulated with a 14-gauge catheter. One group of animals (n = 6) was intubated and manually ventilated, a second received PPV via BVM (n = 7), and a third group received 100% oxygen via FM (n = 6). After placement of a Swan-Ganz catheter, the carotid catheters were opened, and the animals were exsanguinated. The primary end point was time until death. Secondary end points included central venous pressure, cardiac output, lactate levels, serum creatinine, CO2 levels, and pH measured in 10-minute intervals.

RESULTS

Average survival time in the FM group (50.0 minutes) was not different from the INT (51.1 minutes) and BVM groups (48.5 minutes) (p = 0.84). Central venous pressure was higher in the FM group as compared with the INT 10 minutes into the shock phase (8.3 mm Hg vs. 5.2 mm Hg, p = 0.04). Drop in cardiac output (p < 0.001) and increase in lactate (p < 0.05) was worse in both PPV groups throughout the shock phase. Creatinine levels were higher in both PPV groups (p = 0.04). The FM group was more hypercarbic and acidotic than the two PPV groups during the shock phase (p < 0.001).

CONCLUSION

Although permissive hypoventilation leads to respiratory acidosis, it results in less hemodynamic suppression and better perfusion of vital organs. In severely injured penetrating trauma patients, consideration should be given to immediate transportation without PPV.

Copyright © 2014 by Lippincott Williams & Wilkins

Follow Us


Login

Article Tools

Share

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.