|A new index derived from the cerebrovascular pressure transmission and correlated with consciousness recovery in severely head-injured intensive care patients.|
|PMID: 19923517 Owner: NLM Status: MEDLINE|
|BACKGROUND: In patients with serious head trauma, a moderate (20-25 mm Hg) mean level of intracranial pressure (ICP) may fail to distinguish patients with a real deteriorated intracranial status from those who are stable or improving. Because of these limitations, we analyzed the ICP curve in search of other relevant information regarding cerebrovascular pressure transmission. We looked for parameters with physiological meaning extracted from spectral analysis of cerebrovascular pressure transmission and correlated with consciousness recovery in patients with severe head injuries. METHODS: A prospective cohort study was conducted in an intensive care unit of the University Hospital, Montpellier, France, from December 2003 to December 2005. Thirty consecutive patients admitted for severe head trauma were subjected to sedatives, mechanical ventilation, and intraparenchymatous recording of ICP and were evaluated with Glasgow Outcome Scale score. Simultaneous 60-s recordings of ICP and arterial blood pressure (BP) signals, beginning as soon as possible after head trauma, were repeated until death or clinical stabilization, every 15 min, with physicians blinded to the patients' data. Spectra of ICP and BP waveforms were computed with Fourier transform. Amplitudes of cardiac and respiratory harmonics were analyzed. Cardiac (or respiratory) gain was defined as the ratio of amplitudes of cardiac (or respiratory) harmonic of ICP to BP signals and referred to as Gc and Gr, respectively. RESULTS: Twenty of the 30 enrolled patients recovered consciousness (Glasgow Outcome Scale score = 3, 4, or 5). Gr/Gc averaged over the whole recording period performed better in discriminating consciousness recovery (area under receiver operating characteristic [ROC] curve: 0.98; 95% confidence interval [CI]: 0.91-1) than ICP (0.76; 95% CI: 0.54-0.97), cerebral perfusion pressure (0.75; 95% CI: 0.53-0.97) and Gc (0.77; 95% CI: 0.57-0.99) (P < 0.001 for each comparison). When considering the recording period 30 h posttrauma (hpt), 162 hpt, a value of Gr/Gc > or =4 was always associated with consciousness recovery, and the relative risk was equal to 9 (95% CI: 1.42-57.12). CONCLUSIONS: Gr/Gc, which characterizes the cerebrovascular transmission, better discriminates bad evolution than high values of ICP or low values of cerebral perfusion pressure in patients with severe head trauma. A reduction in Gr/Gc ratio might be an early alarm signaling worsening intracranial hemodynamic conditions.|
|Jean-Paul Roustan; Dorine Neveu; Yoan Falquet; Laurent Barral; Patrick Chardon; Xavier Capdevila|
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|Type: Journal Article; Research Support, Non-U.S. Gov't|
|Title: Anesthesia and analgesia Volume: 109 ISSN: 1526-7598 ISO Abbreviation: Anesth. Analg. Publication Date: 2009 Dec|
|Created Date: 2009-11-20 Completed Date: 2009-12-03 Revised Date: -|
Medline Journal Info:
|Nlm Unique ID: 1310650 Medline TA: Anesth Analg Country: United States|
|Languages: eng Pagination: 1883-91 Citation Subset: AIM; IM|
|Département d'Anesthésie-Réanimation A, Hôpital Lapeyronie, Centre Hospitalier Universitaire, Montpellier 34295, France. email@example.com|
|APA/MLA Format Download EndNote Download BibTex|
Blood Pressure Determination
Craniocerebral Trauma / diagnosis*, mortality, physiopathology
France / epidemiology
Glasgow Outcome Scale
Health Status Indicators*
Intensive Care Units*
Monitoring, Physiologic* / methods
Predictive Value of Tests
Recovery of Function
Severity of Illness Index
Signal Processing, Computer-Assisted
|Anesth Analg. 2009 Dec;109(6):1726-7
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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