Controlled blast exposure during forced explosive entry training and mild traumatic brain injury.

BACKGROUND: There is a paucity of data regarding the pathophysiology and short- and long-term neurologic consequences of primary blast injury in humans. The purpose of this investigation was to test the feasibility of implementing a research protocol in the context of a forced explosive entry training course. METHODS: Instructors (n = 4) and students (n = 10) completing the Police Explosives Technicians-Forced Entry Instructors course were recruited to participate in the study. Participants underwent a physical examination, tests of postural stability and vestibular ataxia, and a neurocognitive battery 1 day before and 10 days following practical forced explosive entry exercises. RESULTS: The instructors reported significantly more blast exposures in their careers than the students (p < 0.05). Seventy-five percent of the instructors and 50% of the students reported a history of trauma to the head. A minority of the participants had deficits on cranial nerve, vestibular ataxia, and neurocognitive tests which did not change significantly postexposure. All the instructors and most of the students (90%) demonstrated postural stability deficits at baseline which did not change significantly postexposure. CONCLUSIONS: Studying the effects of blast exposure on the human brain in a controlled experimental setting is not possible. Forced explosive entry training courses afford an opportunity to begin examining this issue in real time in a controlled setting. This study underscores the importance of baseline testing of troops, of the consideration of subclinical implications of blast exposure, and of continued studies of the effects of blast exposures, including repeated exposures on the human brain.

The value of serum biomarkers in prediction models of outcome after mild traumatic brain injury.

BACKGROUND: To determine, using a civilian model of mild traumatic brain injury (TBI), the added value of biomarker sampling upon prognostication of outcome at 1 week and 6 weeks postinjury. METHODS: The Galveston Orientation and Amnesia test was administered, and blood samples for serum protein S100B and neuron-specific enolase (NSE) were collected from 141 emergency department patients within 4 hours of a suspected mild TBI (mTBI). The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) was administered via telephone 3 days postinjury. Patients were assessed by a physician at 1 week (n = 113; 80%) and 6 weeks (n = 95; 67%) postinjury. Neurocognitive and postural stability measures were also administered at these follow-ups. RESULTS: Levels of S100B and NSE were found to be abnormally elevated in 49% and 65% of patients with TBI, respectively. Sixty-eight percent and 38% of the patients were considered impaired at 1 week and 6 weeks postinjury, respectively. Stepwise logistic regression modeling identified admission Galveston Orientation and Amnesia test score, S100B level, and RPQ score at day 3 postinjury to be predictive of poor outcome at 1 week postinjury (c-statistic 0.877); female gender, loss of consciousness, NSE level, and RPQ score at day 3 postinjury were predictive of poor outcome at 6 weeks postinjury (c-statistic 0.895). The discriminative power of the biomarkers alone was limited. CONCLUSIONS: Biomarkers, in conjunction with other readily available determinants of outcome assessed in the acute period after injury, add value in the early prognostication of patients with mTBI. Our findings are consistent with the notion that S100B and NSE point to biological mechanisms underlying poor outcome after mTBI.

Validation and evaluation of two observational pain assessment tools in a trauma and neurosurgical intensive care unit.

BACKGROUND: Studies have demonstrated that patients in the intensive care unit experience high levels of pain. While many of these patients are nonverbal at some point during their stay, there are few valid tools available to assess pain in this group. OBJECTIVES: To evaluate the validity and clinical utility of two pain assessment tools, the revised Adult Non-Verbal Pain Scale (NVPS-R) and the Critical Care Pain Observation Tool (CPOT), in a trauma and neurosurgical patient population. METHODS: Patients were assessed using the NVPS-R and CPOT by trained intensive care unit nurses (n=23) and research assistants before, during and after two procedures: turning of the patient (nociceptive procedure) and noninvasive blood pressure cuff inflation (non-nociceptive procedure). Communicative patients were also asked to report their level of pain during each assessment. RESULTS: A total of 66 patients (34 communicative, 32 noncommunicative) were included in the study. CPOT and NVPS-R scores increased significantly when participants were exposed to turning, but not during noninvasive blood pressure measurement (repeated measures ANOVA: CPOT, F=5.81, P=0.019; NVPS-R, F=5.32, P=0.025) supporting discriminant validity. CPOT and NVPS-R scores were significantly higher during the turning procedure for patients who had indicated that they were in pain versus those who were not, indicating criterion validity. Inter-rater reliability was generally higher for the CPOT than NVPS-R. Nurses rated the feasibility of the two tools as comparable but provided higher ratings of acceptability for the CPOT. CONCLUSIONS: While the present study supports the use of the CPOT and the NVPS-R with critically ill trauma and neurosurgical patients, further research should explore the role of vital signs in pain.

Patient satisfaction and documentation of pain assessments and management after implementing the adult nonverbal pain scale.

BACKGROUND: Accurate assessment and management of pain in critically ill patients who are nonverbal or cognitively impaired is challenging. No widely accepted assessment tool is currently in place for assessing pain in these patients. OBJECTIVES: To evaluate the effect of implementing a new pain assessment tool in a trauma/neurosurgery intensive care unit. METHODS: Staff and patient satisfaction questionnaires and retrospective chart reviews were used before and after implementation of the Nonverbal Pain Scale. The questionnaire responses, frequency of pain documentation, and amount of pain medication given were compared from before to after implementation. RESULTS: Most staff (78%) ranked the tool as easy to use. Implementation of the tool increased staff confidence in assessing pain in nonverbal, sedated patients (57% before vs 81% after implementation, P = .02) and increased the number of pain assessments documented by the nursing staff for noncommunicative patients per day in the intensive care unit (2.2 before vs 3.4 after, P = .02). Patients reported decreased retrospective pain ratings (8.5 before vs 7.2 after, P = .04) and a trend toward a decrease in the time required to receive pain medication (38% before vs 10% after requiring >5 minutes to receive medication, P = .06). CONCLUSIONS: Implementation of the Nonverbal Pain Scale in a critical care setting improved patients' ratings of their pain experience, improved documentation by nurses, and increased nurses' confidence in assessing pain in nonverbal patients.