2.50
Hdl Handle:
http://hdl.handle.net/10755/157822
Type:
Presentation
Title:
Pressure Variability and Long-Term Outcome After Subaracnoid Hemorrhage
Abstract:
Pressure Variability and Long-Term Outcome After Subaracnoid Hemorrhage
Conference Sponsor:Western Institute of Nursing
Conference Year:2006
Author:Kirkness, Catherine, PhD, RN, CNN(c)
P.I. Institution Name:University of Washington
Title:Research Assistant Professor
Contact Address:Biobehavioral Nursing & Hlth Sys, Box 357266, Seattle, WA, 98195, USA
Contact Telephone:206-221-7971
Co-Authors:Robert L. Burr, MSEE, PhD; Pamela H. Mitchell, PhD, RN, FAAN, FAHA
Purposes/Aims: The purpose of this study was to examine the predictability of long-term functional outcome from measures of variability in arterial blood pressure (ABP), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) signals measured in patients with cerebral aneurysms admitted to the intensive care unit (ICU). Background: Much of the traditional focus of care in the ICU revolves around maintaining ABP, ICP, and CPP pressure levels within prescribed ranges. However recent research suggests that consideration of the dynamic variability of the pressure signals provides additional information about physiologic system functioning, potentially reflecting dimensions of adaptive capacity.
Methods: ABP, ICP, and CPP were monitored continuously for four days in 96 patients (GENDER: 76% Female; AGE: Mean +/- SD = 53.4 +/- 12.6), admitted to an ICU for the management of cerebral aneurysms. Variability indices of the ABP, ICP, and CPP signals were calculated to reflect three different time scales (24-hour, hourly, and difference of sequential 5-second averages). Variability at the 24-hour and hourly time scales was expressed as the median absolute deviation. At the 5-second time scale, variability was expressed as the root mean square successive difference between adjacent 5-second averages. Long-term functional outcome was assessed 6 months later using the 8-point Extended Glasgow Outcome Scale (1 = death, 8 = upper good recovery). Results: Pressure (ABP, ICP, CPP) variability indices were better predictors of 6-month functional outcome than mean pressure levels. Indices reflecting greater pressure variability on shorter time scales (particularly 5-second) were positively associated with better long term outcome (typical p<0.001), while greater variability on a 24-hour scale was related to poorer outcomes (typical p <0.001), controlling for initial neurologic condition. Implications: Beyond the measurement of ABP, ICP, and CPP levels in patients with cerebral aneurysms managed in the ICU, simple measures of variability of these signals provide prognostic information regarding long-term functional outcome. The direction of association of variability to outcome differed at different time scales. There is a need for further study to ascertain the most appropriate and clinically meaningful measures to assess dynamic variability of ABP, ICP, and CPP signals in the ICU, and to determine the meaning of this variability in terms of physiologic adaptive capacity in acutely ill individuals with cerebral aneurysms. This can provide a basis for the development and testing of nursing interventions directed at maximizing adaptive capacity and/or minimizing stressors in high-risk individuals. Funded by NIH NINR R01NR004901.
Repository Posting Date:
26-Oct-2011
Date of Publication:
17-Oct-2011
Sponsors:
Western Institute of Nursing

Full metadata record

DC FieldValue Language
dc.typePresentationen_GB
dc.titlePressure Variability and Long-Term Outcome After Subaracnoid Hemorrhageen_GB
dc.identifier.urihttp://hdl.handle.net/10755/157822-
dc.description.abstract<table><tr><td colspan="2" class="item-title">Pressure Variability and Long-Term Outcome After Subaracnoid Hemorrhage</td></tr><tr class="item-sponsor"><td class="label">Conference Sponsor:</td><td class="value">Western Institute of Nursing</td></tr><tr class="item-year"><td class="label">Conference Year:</td><td class="value">2006</td></tr><tr class="item-author"><td class="label">Author:</td><td class="value">Kirkness, Catherine, PhD, RN, CNN(c)</td></tr><tr class="item-institute"><td class="label">P.I. Institution Name:</td><td class="value">University of Washington</td></tr><tr class="item-author-title"><td class="label">Title:</td><td class="value">Research Assistant Professor</td></tr><tr class="item-address"><td class="label">Contact Address:</td><td class="value">Biobehavioral Nursing & Hlth Sys, Box 357266, Seattle, WA, 98195, USA</td></tr><tr class="item-phone"><td class="label">Contact Telephone:</td><td class="value">206-221-7971</td></tr><tr class="item-email"><td class="label">Email:</td><td class="value">kirkness@u.washington.edu</td></tr><tr class="item-co-authors"><td class="label">Co-Authors:</td><td class="value">Robert L. Burr, MSEE, PhD; Pamela H. Mitchell, PhD, RN, FAAN, FAHA</td></tr><tr><td colspan="2" class="item-abstract">Purposes/Aims: The purpose of this study was to examine the predictability of long-term functional outcome from measures of variability in arterial blood pressure (ABP), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) signals measured in patients with cerebral aneurysms admitted to the intensive care unit (ICU). Background: Much of the traditional focus of care in the ICU revolves around maintaining ABP, ICP, and CPP pressure levels within prescribed ranges. However recent research suggests that consideration of the dynamic variability of the pressure signals provides additional information about physiologic system functioning, potentially reflecting dimensions of adaptive capacity. <br/>Methods: ABP, ICP, and CPP were monitored continuously for four days in 96 patients (GENDER: 76% Female; AGE: Mean +/- SD = 53.4 +/- 12.6), admitted to an ICU for the management of cerebral aneurysms. Variability indices of the ABP, ICP, and CPP signals were calculated to reflect three different time scales (24-hour, hourly, and difference of sequential 5-second averages). Variability at the 24-hour and hourly time scales was expressed as the median absolute deviation. At the 5-second time scale, variability was expressed as the root mean square successive difference between adjacent 5-second averages. Long-term functional outcome was assessed 6 months later using the 8-point Extended Glasgow Outcome Scale (1 = death, 8 = upper good recovery). Results: Pressure (ABP, ICP, CPP) variability indices were better predictors of 6-month functional outcome than mean pressure levels. Indices reflecting greater pressure variability on shorter time scales (particularly 5-second) were positively associated with better long term outcome (typical p<0.001), while greater variability on a 24-hour scale was related to poorer outcomes (typical p <0.001), controlling for initial neurologic condition. Implications: Beyond the measurement of ABP, ICP, and CPP levels in patients with cerebral aneurysms managed in the ICU, simple measures of variability of these signals provide prognostic information regarding long-term functional outcome. The direction of association of variability to outcome differed at different time scales. There is a need for further study to ascertain the most appropriate and clinically meaningful measures to assess dynamic variability of ABP, ICP, and CPP signals in the ICU, and to determine the meaning of this variability in terms of physiologic adaptive capacity in acutely ill individuals with cerebral aneurysms. This can provide a basis for the development and testing of nursing interventions directed at maximizing adaptive capacity and/or minimizing stressors in high-risk individuals. Funded by NIH NINR R01NR004901.</td></tr></table>en_GB
dc.date.available2011-10-26T20:14:16Z-
dc.date.issued2011-10-17en_GB
dc.date.accessioned2011-10-26T20:14:16Z-
dc.description.sponsorshipWestern Institute of Nursingen_GB
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