JOURNAL ARTICLE
RESEARCH SUPPORT, NON-U.S. GOV'T
RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
Add like
Add dislike
Add to saved papers

Intrathoracic pressure regulation improves vital organ perfusion pressures in normovolemic and hypovolemic pigs.

Resuscitation 2006 September
BACKGROUND: The intrathoracic pressure regulator (ITPR) was created to improve hemodynamics by generating continuous negative airway pressure between positive pressure ventilations to enhance cardiac preload in apnoeic animals. In normovolemic and hypovolemic pigs, we tested the hypothesis that continuous negative intrathoracic pressure set at -5 or -10mmHg, interrupted only for intermittent positive pressure ventilations, would decrease intracranial (ICP) and right atrial (RAP) pressure, and increase mean arterial pressure (MAP).

METHODS: Twelve pigs were anesthetized with propofol and ventilated with a bag. The ITPR was used to vary baseline endotracheal pressures (ETPs) for 5min periods in the following sequence: 0, -5, 0, -10, 0mmHg under normovolemic conditions. Six pigs were bled 50% (32.5+/-mL/kg) of their estimated blood volume and the airway pressure sequence was repeated. Six other pigs were bled 35% (22.75+/-mL/kg) of their estimated blood volume and the same airway pressure sequence was repeated. Intracranial, aortic, right atrial pressures, arterial blood gases, end tidal CO(2) (ETCO(2)), were measured. ANOVA was used for statistical analysis. Linear regression analysis was performed for ETP and ICP.

RESULTS: Mean arterial and vital organ perfusion pressures were significantly improved and RA pressure significantly decreased with the use of the ITPR; the effect was greater with the more negative ETPs and lower circulating blood volume. The change of ICP was linearly related to the ETP and blood loss: DeltaICP=[1.22-0.84(1-%blood loss/100)]xETP, r(2)=0.88 (in mmHg), p<0.001. There were no adverse device effects and there was a significant increase of ETCO(2) with the use of ITPR.

CONCLUSION: The ITPR decreased RAP and ICP significantly and improved mean arterial and cerebral and coronary perfusion pressures without affecting acid base balance severely. The decrease in ICP was directly proportional to the reduction in intrathoracic pressure. The effects were more pronounced in severe hypovolemic and hypotensive states with more negative ETP pressure.

Full text links

We have located links that may give you full text access.
Can't access the paper?
Try logging in through your university/institutional subscription. For a smoother one-click institutional access experience, please use our mobile app.

For the best experience, use the Read mobile app

Mobile app image

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app

All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

By using this service, you agree to our terms of use and privacy policy.

Your Privacy Choices Toggle icon

You can now claim free CME credits for this literature searchClaim now

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app