Catherine J. Kirkness

Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Purpose— The aim of this guideline is to present current and comprehensive recommendations for the diagnosis and treatment of aneurysmal subarachnoid hemorrhage (aSAH). Methods— A formal literature search of MEDLINE (November 1, 2006, through May 1, 2010) was performed. Data were synthesized with the use of evidence tables. Writing group members met by teleconference to discuss data-derived recommendations. The American Heart Association Stroke Councils Levels of Evidence grading algorithm was used to grade each recommendation. The guideline draft was reviewed by 7 expert peer reviewers and by the members of the Stroke Council Leadership and Manuscript Oversight Committees. It is intended that this guideline be fully updated every 3 years. Results— Evidence-based guidelines are presented for the care of patients presenting with aSAH. The focus of the guideline was subdivided into incidence, risk factors, prevention, natural history and outcome, diagnosis, prevention of rebleeding, surgical and endovascular repair of ruptured aneurysms, systems of care, anesthetic management during repair, management of vasospasm and delayed cerebral ischemia, management of hydrocephalus, management of seizures, and management of medical complications. Conclusions— aSAH is a serious medical condition in which outcome can be dramatically impacted by early, aggressive, expert care. The guidelines offer a framework for goal-directed treatment of the patient with aSAH.

Impaired Cerebral Autoregulation and 6-Month Outcome in Children with Severe Traumatic Brain Injury: Preliminary Findings

The objective of this study was to describe the incidence of impaired cerebral autoregulation and to describe the relationship between impaired cerebral autoregulation and outcome after severe pediatric traumatic brain injury (TBI). We prospectively examined cerebral autoregulation in 28 children ≤17 (10 ± 5) years with a Glasgow coma scale score <9 within the first 72 h of pediatric intensive care unit admission. Children with isolated focal TBI were excluded. Glasgow outcome scores (GOS) were collected at hospital discharge, as well as 3 and 6 months after severe TBI. GOS <4 reflected poor outcome. Cerebral autoregulation was impaired in 12/28 children. An autoregulatory index <0.4 was associated with GOS <4 at 6 months (p = 0.005). Impaired cerebral autoregulation, early after severe pediatric TBI, was associated with a poor 6-month outcome.

Is there a Sex Difference in the Course Following Traumatic Brain Injury

Traumatic brain injury (TBI) is a significant cause of death and disability in the United States. Sex has not been thoroughly examined as a factor that may influence outcome following TBI. Clinical studies involving humans that have focused on sex and TBI outcome have yielded inconclusive results, yet sex-related physiologic differences have been demonstrated in animal studies. The purpose of this study is to examine the interaction of sex and age in relation to outcome at 3 and 6 months postinjury in a population of individuals with TBI. The sample includes 157 subjects (124 males, 33 females), 16 to 89 years of age, admitted to a level 1 trauma center following TBI. Physiologic data and information about injury severity and clinical course were gathered during hospitalization. Outcome was assessed at 3 and 6 months postinjury using the Extended Glasgow Outcome Scale (GOSE) and Functional Status Examination (FSE). In this sample, there was a significant relationship between sex and age with respect to functional outcome at 6 months following TBI, controlling for initial injury severity. Females age 30 years or older had significantly poorer outcome as measured by the GOSE (P = 0.031) and the FSE (P = 0.037) than either males or younger females. There was also a very different rate of recovery, with women age 30 years and older, on average, showing no improvement between 3 and 6 months postinjury. Further study is needed to elucidate the reasons why sex may affect outcome following TBI.

Intracranial pressure waveform analysis: clinical and research implications.

&NA; Assessment of intracranial adaptive capacity is vital in critically ill individuals with acute brain injury because there is the potential that nursing care activities and environmental stimuli to result in clinically significant increases in intracranial pressure (ICP) in a subset of individuals with decreased intracranial adaptive capacity. ICP waveform analysis provides information about intracranial dynamics that can help identify individuals who have decreased adaptive capacity and are at risk for increases in ICP and decreases in cerebral perfusion pressure, which may contribute to secondary brain injury and have a negative impact on neurologic outcome. The ability to identify highrisk individuals allows nurses to initiate interventions targeted at decreasing adaptive demand or increasing adaptive capacity in these individuals. Changes in the ICP waveform occur under various physiologic and pathophysiologic conditions and may provide valuable information about intracranial adaptive capacity. Simple visual assessment of the ICP waveform for increased amplitude and P2 elevation is clinically relevant and has been found to provide a rough indicator of decreased adaptive capacity. Advanced ICP waveform analysis techniques warrant further study as a means of dynamically assessing intracranial adaptive capacity.

Detrended Fluctuation Analysis of Intracranial Pressure Predicts Outcome Following Traumatic Brain Injury

Detrended fluctuation analysis (DFA) is a recently developed technique suitable for describing scaling behavior of variability in physiological signals. The purpose of this study is to explore applicability of DFA methods to intracranial pressure (ICP) signals recorded in patients with traumatic brain injury (TBI). In addition to establishing the degree of fit of the power-law scaling model of detrended fluctuations of ICP in TBI patients, we also examined the relationship of DFA coefficients (scaling exponent and intercept) to: 1) measures of initial neurological functioning; 2) measures of functional outcome at six month follow-up; and 3) measures of outcome, controlling for patient characteristics, and initial neurological status. In a sample of 147 moderate-to-severely injured TBI patients, we found that a higher DFA scaling exponent is significantly associated with poorer initial neurological functioning, and that lower DFA intercept and higher DFA scaling exponent jointly predict poorer functional outcome at six month follow-up, even after statistical control for covariates reflecting initial neurological condition. DFA describes properties of ICP signal in TBI patients that are associated with both initial neurological condition and outcome at six months postinjury.

Cerebral autoregulation and outcome in acute brain injury

The purpose of this study was to examine the relationship between Czosnyka and others’ Pressure Reactivity Index (PRx) and neurologic outcome in patients with acute brain injury, including traumatic brain injury (TBI) and cerebrovascular pathology. PRx measures the correlation between arterial blood pressure and intracranial pressure waves and may reflect cerebral autoregulation in response to blood pressure changes. A negative PRx reflects intact cerebrovascular response, whereas a positive PRx reflects impaired response. Positive PRx has been shown to correlate with poorer outcome in individuals with TBI, but these findings have not been confirmed by replication in other studies, nor have PRx values been reported for individuals with cerebrovascular pathology. In this study, PRx was determined in 52 patients with TBI (n = 27) or cerebrovascular pathology (n = 25). Hierarchical linear regression was used to evaluate the contribution of PRx to outcome, controlling for age and Glasgow Coma Scale score. Analysis of all subjects together did not support the previously reported relationship between PRx and outcome. However, for those with TBI, positive PRx was a significant predictor of negative outcome (P = 0.03). For those with cerebrovascular pathology, the effect was not significant (P = 0.10) and was in the opposite direction. For individuals with TBI, PRx may provide useful information related to cerebral autoregulation that is predictive of outcome. The meaning of PRx in individuals with cerebrovascular pathology is unclear, and further study is needed to examine the paradoxical findings observed.

Fever Management Practices of Neuroscience Nurses: National and Regional Perspectives

&NA; Neuroscience patients with fever may have worse outcomes than those who are afebrile. However, neuroscience nurses who encounter this common problem face a translational gap between patient‐outcomes research and bedside practice because there is no current evidence‐based standard of care for fever management of the neurologically vulnerable patient. The aim of this study was to determine if there are trends in national practices for fever and hyperthermia management of the neurologically vulnerable patient. A 15‐item mailed questionnaire was used to determine national and regional trends in fever and hyperthermia management and decision making by neuroscience nurses. Members of the American Association of Neuroscience Nurses were surveyed (N = 1,225) and returned 328 usable surveys. Fewer than 20% of respondents reported having an explicit fever management protocol in place for neurologic patients, and 12.5% reported having a nonspecific patient protocol available for fever management. Several clear and consistent patterns in interventions for fever and hyperthermia management were seen nationally, including acetaminophen administration at a dose of 650 mg every 4 hours, ice packs, water cooling blankets, and tepid bathing. However, regional differences were seen in intervention choices and initial temperature to treat.

The impact of aneurysmal subarachnoid hemorrhage on functional outcome.

&NA; Despite advances in the management of aneurysmal subarachnoid hemorrhage (SAH), a significant percentage of survivors are left with persistent cognitive, behavioral, and emotional changes that affect their day‐to‐day lives. This article describes outcome at 3 months after aneurysmal SAH in 61 patients, using the Extended Glasgow Outcome Scale (GOSE) and the Functional Status Examination (FSE). The GOSE provides a measure of overall functional outcome but does not address the specifics of functional limitations. The FSE, in addition to identifying functional limitations, provides insight into factors contributing to them and the extent to which SAH survivors perceive them as affecting their day‐to‐day activities. The findings of this study demonstrate that SAH survivors have considerable limitations in functional status in almost all areas of daily living at 3 months following SAH. The limitations were attributed to a variety of physical, cognitive, and emotional factors, and they were reported to be moderately to severely bothersome in almost half of the individuals. The findings highlight the need for appropriate rehabilitation, education, and support for SAH survivors and their families to enhance coping and improve quality of life, given the substantial and persistent impact of SAH.

Relationship of cerebral perfusion pressure levels to outcome in traumatic brain injury

This study examined the relationship of cumulative percent time that cerebral perfusion pressure (CPP) fell below set thresholds to outcome in individuals with traumatic brain injury (TBI). The sample included 157 patients (16 to 89 years of age, 79%, male) admitted to an intensive care unit at an academic medical center who underwent invasive arterial blood pressure and intracranial pressure monitoring. CPP levels were recorded continuously during the first 96 hours of monitoring. Initial neurologic status was assessed using the post-resuscitation Glasgow Coma Scale. Outcome was evaluated at hospital discharge and at six months post-injury using the Extended Glasgow Outcome Scale (GOSE). The relationship of cumulative periods of low CPP to outcome was evaluated using hierarchical and binary logistic regression analysis, controlling for age, gender, and injury severity. Patients experiencing less cumulative percent time below specific CPP thresholds were more likely to have better outcome at discharge (55 mm Hg, p = .004; 60 mm Hg, p = .008; 65 mm Hg, p = .024; 70 mm Hg, p = .016). Although differences in GOSE scores at six months were not significant, those with less time below CPP thresholds were more likely to survive. Accumulated episodes of low CPP had a stronger negative relationship with outcome in patients with more severe primary brain injury.

Hypothermia and rapid rewarming is associated with worse outcome following traumatic brain injury.

Purpose:The purpose of the present study was to determine (1) the prevalence and degree of hypothermia in patients on emergency department admission and (2) the effect of hypothermia and rate of rewarming on patient outcomes. Methods:Secondary data analysis was conducted on patients admitted to a level I trauma center following severe traumatic brain injury (n = 147). Patients were grouped according to temperature on admission according to hypothermia status and rate of rewarming (rapid or slow). Regression analyses were performed. Findings:Hypothermic patients were more likely to have lower postresuscitation Glasgow Coma Scale scores and a higher initial injury severity score. Hypothermia on admission was correlated with longer intensive care unit stays, a lower Glasgow Coma Scale score at discharge, higher mortality rate, and lower Glasgow outcome score–extended scores up to 6 months postinjury (P < .05). When controlling for other factors, rewarming rates more than 0.25°C/h were associated with lower Glasgow Coma Scale scores at discharge, longer intensive care unit length of stay, and higher mortality rate than patients rewarmed more slowly although these did not reach statistical significance. conclusion:Hypothermia on admission is correlated with worse outcomes in brain-injured patients. Patients with traumatic brain injury who are rapidly rewarmed may be more likely to have worse outcomes. Trauma protocols may need to be reexamined to include controlled rewarming at rates 0.25°C/h or less.