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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.

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.

Background: Research suggests that intracranial pressure (ICP) dynamics beyond just absolute ICP level provide information reflecting intracranial adaptive capacity. Specifically, evidence indicates that physiologic variability provides information about system functioning that may reflect dimensions of adaptive capacity. The purpose of this study was to examine the association between ICP variability in patients following moderate to severe traumatic brain injury (TBI) and outcome at hospital discharge and 6 months post-injury., Methods: ICP was monitored continuously for 4 days in 147 patients (78% male; mean (SD) age = 37 years (18 years)). ICP variability indices were calculated for four time scales (24 h, 60 min, 5 min and 5 s). Functional outcome was assessed using the Extended Glasgow Outcome Scale (GOSE). Logistic regression was used to estimate odds of survival or favorable outcome, and ordinal regression was used to estimate odds for outcome above versus below GOSE thresholds, predicted by ICP variability, controlling for age, gender, Glasgow Coma Scale motor score, craniectomy, and ICP level., Findings: ICP variability indices were better predictors of 6-month outcome than mean ICP. Survival was significantly associated with greater 5-s ICP variability (p < 0.001). Higher ICP variability on shorter time scales was associated with better functional outcome (5-s RMSSD, 5-min SD: p < 0.002; 60-min SD: p < 0.011)., Conclusions: ICP variability may reflect the degree of intactness of intracranial adaptive ability.

Fever, in the presence of traumatic brain injury (TBI), is associated with worsened neurologic outcomes. Studies prior to the publication of management guidelines revealed an undertreatment of fever in patients with neurologic insults. Presently the adult TBI guidelines state that maintenance of normothermia should be a standard of care therefore improvement in management of fever in these patients would be expected. The specific aims of the study were to: (1) determine the incidence of fever (T>or=38.5 degrees C) in a population of critically ill patients with TBI; (2) describe what interventions were recorded by intensive care unit (ICU) nurses in managing fever; (3) ascertain the rate of adherence with published normothermia guidelines. Medical record review of available hospital records was conducted on patients admitted to a level I trauma center following severe TBI (N=108) from the parent study. Temperature data was abstracted and contemporaneous nursing documentation was examined for evidence of intervention for fever and adherence with published standards. Data analyses were performed that included descriptive statistics. Seventy-nine percent of TBI patients (85/108) had at least one recorded fever event while in the ICU. However in only 31% of events did the patient receive any documented intervention by nursing staff for the elevated temperature. The most frequently documented intervention was pharmacologic (358/1166 elevations). Other nursing actions (e.g. use of fan) accounted for a minority (<1%) of nursing interventions documented. Patients were more likely to have a high temperature that exceeded 40 degrees C (13%) than a temperature that was normothermic (5%). There continues to be an under treatment of fever in patients with TBI by critical care nurses despite our knowledge of its negative effects on outcomes. There remains a gap in translation between patient outcomes research and bedside practice that needs to be overcome, thus research efforts need to now focus on understanding nurses' decision-making processes and the best methods of fever reduction in patients with TBI.

Background: Clinical bedside monitoring systems do not provide prominent displays of data on cerebral perfusion pressure (CPP). Immediate visual feedback would allow more rapid intervention to prevent or minimize suboptimal pressures., Objective: To evaluate the effect of a highly visible CPP display on immediate and long-term functional outcome in patients with traumatic brain injury., Methods: A total of 157 patients with traumatic brain injury at a level 1 trauma center who had invasive arterial blood pressure and intracranial pressure monitoring were randomized to beds with or without an additional, prominent continuous CPP display. Primary end points were scores on the Extended Glasgow Outcome Scale (GOSE) and Functional Status Examination (FSE) 6 months after injury. Secondary end points were GOSE scores at discharge and 3 months after injury and FSE score 3 months after injury., Results: Although GOSE and FSE scores at 6 months were better in the group with the highly visible CPP display, the differences were not significant. Slope of recovery for GOSE and FSE over all follow-up time points did not differ significantly between groups. However, the intervention's positive effect on odds of survival at hospital discharge was strong and significant. Within a subgroup of more severely injured patients, the intervention group was much less likely than the control group to have CPP deviations., Conclusions: The presence of a highly visible display of CPP was associated with significantly better odds of survival and overall condition at discharge.

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.

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.

This study developed and tested the acceptability of a computer interface intended to provide better information about CPP to Neuro Intensive Care nurses. Maintaining adequate CPP is crucial in preventing secondary brain injury, yet current monitoring data displays have poor ergonomics that minimize usable information for clinicians. Information systems developmental methods were used to 1) formulate the model for CPP information display, 2) develop the system with end-users, and 3) install the system in the Neuro Intensive Care Unit. System testing for effects on clinicians and patient outcomes is occurring in a randomized clinical trial. Metaphor graphic and universal graphic displays were tested with 37 staff nurses from three intensive care units using continuous ICP monitoring. Nursing staff preferred an augmented universal data display to the metaphor graphics, endorsing a modified trend area graph with threshold-dependent properties. The preferred model was programmed in Visual Basic and installed on small computers that were randomly allocated as live or blank displays to beds of newly admitted head injury or aneurysmal subarachnoid hemorrhage patients with continuous monitoring. Nursing acceptability of the information interface was achieved through the use of end-user focus groups that resulted in modifying the metaphor graphic approach to a more readily understandable one.

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.