Journal article
Positive end-expiratory pressure oscillation facilitates brain vascular reactivity monitoring
Journal of applied physiology (1985), Vol.113(9), pp.1362-1368
11/01/2012
DOI: 10.1152/japplphysiol.00853.2012
PMID: 22984248
Abstract
The pressure reactivity index (PRx) identifies optimal cerebral perfusion pressure after traumatic brain injury. We describe a method to improve PRx precision by induced variations in arterial blood pressure (ABP) using positive end-expiratory pressure (PEEP) modulation ( iPRx). Neonatal swine ( n = 10) were ventilated with static PEEP and then with PEEP oscillated between 5 and 10 cmH2O at a frequency of 1/min. PRx was recorded as a moving correlation coefficient between ABP and intracranial pressure (ICP) from spontaneous ABP activity (0.05-0.003 Hz) during static PEEP. iPRx was similarly recorded with PEEP oscillation-induced ABP waves. The lower limit of autoregulation (LLA) was delineated with continuous cortical laser Doppler flux monitoring. PEEP oscillation increased autoregulation-monitoring precision. The ratios of median absolute deviations to range of possible values for the PRx and iPRx were 9.5% (8.3–13.7%) and 6.2% (4.2–8.7%), respectively ( P = 0.006; median, interquartile range). The phase-angle difference between ABP and ICP above LLA was 161° (150°–166°) and below LLA, −31° (−42° to 12°, P < 0.0001). iPRx above LLA was −0.42 (−0.67 to −0.29) and below LLA, 0.32 (0.22–0.43, P = 0.0004). A positive iPRx was 97% specific and 91% sensitive for perfusion pressure below LLA. PEEP oscillation caused stable, low-frequency ABP oscillations that reduced noise in the PRx. Safe translation of these findings to clinical settings is expected to yield more accurate and rapid delineation of individualized optimal perfusion-pressure goals for patients.
Details
- Title: Subtitle
- Positive end-expiratory pressure oscillation facilitates brain vascular reactivity monitoring
- Creators
- Ken M Brady - Anesthesiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas;, Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TexasR. Blaine Easley - Anesthesiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas;, Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TexasKathleen Kibler - Anesthesiology, Texas Children's Hospital, Baylor College of Medicine, Houston, TexasDavid W Kaczka - Anesthesia, Harvard Medical School, Boston, MassachusettsDean Andropoulos - Anesthesiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas;, Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TexasCharles D Fraser - University of Texas at Houston Medical School, Houston, Texas; andPeter Smielewski - Neurosurgical Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, United KingdomMarek Czosnyka - Neurosurgical Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, United KingdomGerald J Adams - Cardiology, Texas Children's Hospital, Baylor College of Medicine, Houston, TexasChristopher J Rhee - Neonatology, Texas Children's Hospital, Baylor College of Medicine, Houston, TexasCraig G Rusin - Cardiology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.113(9), pp.1362-1368
- DOI
- 10.1152/japplphysiol.00853.2012
- PMID
- 22984248
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Language
- English
- Date published
- 11/01/2012
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Anesthesia
- Record Identifier
- 9984006361302771
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