- Poster presentation
- Open access
- Published:
Positive end-expiratory pressure can increase brain tissue oxygen pressure in hypoxemic severe traumatic brain injury patients
Critical Care volume 15, Article number: P41 (2011)
Introduction
Brain tissue oxygen pressure (PtiO2) reflects brain oxygenation and is a useful tool in traumatic brain injury (TBI) patients. Increases in inspired oxygen fraction (FiO2) are related to improvement on PbrO2, but other approaches that aim to improve oxygenation, like increasing positive-end expiratory pressure (PEEP), were not deeply evaluated in humans.
Objective
The aim of this study was to evaluate the effects of three different PEEP levels on PbrO2 of hypoxemic severe TBI patients.
Methods
From February 2007 to February 2011, 36 severe TBI patients admitted to our intensive neurological unit were monitored with PtiO2 through the Licox device (Integra Neuroscience). Seventeen patients remained in the study according to the following inclusion criteria: ratio of arterial oxygen tension to fraction of inspired oxygen (PaO2/FiO2 ratio) <300; cerebral perfusion pressure (CPP) >60 mmHg; intracranial pressure (ICP) <20 mmHg; PtiO2 >20 mmHg; absence of any signal of brain deterioration. These patients were submitted to PEEP levels of 5, 10 and 15 cmH2O, each one for at least 20 minutes. During the three PEEP levels, PtiO2, pulse oxygen saturation (SpO2), ICP and CPP were monitored and statistically analyzed by ANOVA and Bonferroni methods. P < 0.05 was considered statistically significant.
Results
The increase of PEEP level from 5 to 15 cmH2O increased SpO2 from 95.5 ± 2.1 to 98.6 ± 1.2 (P = 0.0001) and PtiO2 from 27.8 ± 6.5 mmHg to 33.9 ± 6.7 mmHg, respectively (P = 0.0001). On the other hand, ICP and CPP did not present statistical significance according to the increase of PEEP levels (8.29 ± 4.44 mmHg to 8.65 ± 4.42 mmHg; P = 0.14 and 94.8 ± 8.2 to 94.6 ± 8.0 mmHg; P = 0.78, respectively). The main characteristics of the evaluated patients are described in Table 1. Changes in PtiO2 and CPP according to the PEEP levels are represented in Figures 1 and 2.
Changes in PtiO 2 according to the PEEP levels.
Changes in CPP according to the PEEP levels.
Conclusion
In hypoxemic severe TBI patients, increasing PEEP levels from 5 to 10 and 15 cmH2O increased PtiO2, without increasing ICP and/or decreasing CPP. Increasing PEEP levels can be an alternative ventilatory approach to improve brain oxygenation besides FiO2.
Author information
Authors and Affiliations
Rights and permissions
This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
About this article
Cite this article
Nemer, S., Santos, R., Caldeira, J. et al. Positive end-expiratory pressure can increase brain tissue oxygen pressure in hypoxemic severe traumatic brain injury patients. Crit Care 15 (Suppl 2), P41 (2011). https://doi.org/10.1186/cc10189
Published:
DOI: https://doi.org/10.1186/cc10189