2.50
Hdl Handle:
http://hdl.handle.net/10755/158243
Type:
Presentation
Title:
Complexity analysis of intracranial pressure
Abstract:
Complexity analysis of intracranial pressure
Conference Sponsor:Western Institute of Nursing
Conference Year:2001
Author:Kirkness, Catherine
P.I. Institution Name:University of Washington
Contact Address:School of Nursing, PO Box 357263, Seattle, WA, 98195, USA
Contact Telephone:206.221.7971
Problem Statement: A subset of individuals with acute brain injury who have decreased cerebrovascular adaptive capacity are at risk for adverse responses to nursing care activities and environmental stimuli that may contribute to secondary brain injury and poorer neurologic outcome. There is currently no valid and reliable means to identify these individuals so that specific nursing interventions can be instituted to minimize or prevent care induced decreases in cerebral perfusion. Theoretical Framework: Increasing evidence suggests that decreased variability and decreased complexity in physiologic systems are associated with disease and pathology. Intracranial pressure (ICP) waveform complexity may reflect the capacity of the intracranial system to dynamically respond to internal and external environmental perturbations, with decreased complexity reflecting decreased adaptive capacity. The purpose of this study was to characterize ICP waveform complexity and examine the correlation of complexity measures with neurologic outcome at hospital discharge. Patients: Records were obtained from fifty-two patients admitted to intensive care units of a university medical center with a diagnosis of traumatic brain injury (TBI, n = 27) or acute cerebrovascular pathology (CV, n = 25) who required invasive ICP monitoring. Methods: ICP waveform data was sampled for 30 minutes. ICP complexity was characterized by calculation of 1/f slope, autoregressive model order one coefficient (AR1), approximate entropy (ApEn), and spectral entropy (Hspect). Neurologic outcome at hospital discharge was assessed using the Glasgow Outcome Scale (GOS). Results: ICP 1/f slope, AR1, ApEn, and Hspect all correlated strongly with one another (r = 0.81 to 0.93). Although other measures did not correlate significantly with neurologic outcome, lower ICP ApEn was predictive of a better GOS score at discharge. Subgroup analysis demonstrated greater complexity in the TBI subgroup than in the CV subgroup. Conclusions: Contrary to a hypothesis of the association of decreased variability with greater pathology, this study demonstrates a correlation between decreased complexity, as reflected by lower ApEn, and better neurologic status at discharge. Decreased ICP complexity may reflect intact cerebrovascular adaptive mechanisms that act to isolate ICP from external influences so as to maintain cerebral perfusion and prevent secondary brain injury. Further study is required to assess the clinical value of ICP complexity measures to identify individuals at high risk for decreases in cerebral perfusion so that nursing interventions can be targeted to prevent or minimize these occurrences and improve neurologic outcome.
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.titleComplexity analysis of intracranial pressureen_GB
dc.identifier.urihttp://hdl.handle.net/10755/158243-
dc.description.abstract<table><tr><td colspan="2" class="item-title">Complexity analysis of intracranial pressure</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">2001</td></tr><tr class="item-author"><td class="label">Author:</td><td class="value">Kirkness, Catherine</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-address"><td class="label">Contact Address:</td><td class="value">School of Nursing, PO Box 357263, 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><td colspan="2" class="item-abstract">Problem Statement: A subset of individuals with acute brain injury who have decreased cerebrovascular adaptive capacity are at risk for adverse responses to nursing care activities and environmental stimuli that may contribute to secondary brain injury and poorer neurologic outcome. There is currently no valid and reliable means to identify these individuals so that specific nursing interventions can be instituted to minimize or prevent care induced decreases in cerebral perfusion. Theoretical Framework: Increasing evidence suggests that decreased variability and decreased complexity in physiologic systems are associated with disease and pathology. Intracranial pressure (ICP) waveform complexity may reflect the capacity of the intracranial system to dynamically respond to internal and external environmental perturbations, with decreased complexity reflecting decreased adaptive capacity. The purpose of this study was to characterize ICP waveform complexity and examine the correlation of complexity measures with neurologic outcome at hospital discharge. Patients: Records were obtained from fifty-two patients admitted to intensive care units of a university medical center with a diagnosis of traumatic brain injury (TBI, n = 27) or acute cerebrovascular pathology (CV, n = 25) who required invasive ICP monitoring. Methods: ICP waveform data was sampled for 30 minutes. ICP complexity was characterized by calculation of 1/f slope, autoregressive model order one coefficient (AR1), approximate entropy (ApEn), and spectral entropy (Hspect). Neurologic outcome at hospital discharge was assessed using the Glasgow Outcome Scale (GOS). Results: ICP 1/f slope, AR1, ApEn, and Hspect all correlated strongly with one another (r = 0.81 to 0.93). Although other measures did not correlate significantly with neurologic outcome, lower ICP ApEn was predictive of a better GOS score at discharge. Subgroup analysis demonstrated greater complexity in the TBI subgroup than in the CV subgroup. Conclusions: Contrary to a hypothesis of the association of decreased variability with greater pathology, this study demonstrates a correlation between decreased complexity, as reflected by lower ApEn, and better neurologic status at discharge. Decreased ICP complexity may reflect intact cerebrovascular adaptive mechanisms that act to isolate ICP from external influences so as to maintain cerebral perfusion and prevent secondary brain injury. Further study is required to assess the clinical value of ICP complexity measures to identify individuals at high risk for decreases in cerebral perfusion so that nursing interventions can be targeted to prevent or minimize these occurrences and improve neurologic outcome.</td></tr></table>en_GB
dc.date.available2011-10-26T20:39:09Z-
dc.date.issued2011-10-17en_GB
dc.date.accessioned2011-10-26T20:39:09Z-
dc.description.sponsorshipWestern Institute of Nursingen_GB
All Items in this repository are protected by copyright, with all rights reserved, unless otherwise indicated.