False-negative FAST examination: associations with injury characteristics and patient outcomes.

STUDY OBJECTIVE: Focused assessment with sonography in trauma (FAST) is widely used for evaluating patients with blunt abdominal trauma; however, it sometimes produces false-negative results. Presenting characteristics in the emergency department may help identify patients at risk for false-negative FAST result or help the physician predict injuries in patients with a negative FAST result who are unstable or deteriorate during observation. Alternatively, false-negative FAST may have no clinical significance. The objectives of this study are to estimate associations between false-negative FAST results and patient characteristics, specific abdominal organ injuries, and patient outcomes. METHODS: This was a retrospective cohort study including consecutive patients who presented to an urban Level I trauma center between July 2005 and December 2008 with blunt abdominal trauma, a documented FAST, and pathologic free fluid as determined by computed tomography, diagnostic peritoneal lavage, laparotomy, or autopsy. Physicians blinded to the study purpose used standardized abstraction methods to confirm FAST results and the presence of pathologic free fluid. Multivariable modeling was used to assess associations between potential predictors of a false-negative FAST result and false-negative FAST result and adverse outcomes. RESULTS: During the study period, 332 patients met inclusion criteria. Median age was 32 years (interquartile range 23 to 45 years), 67% were male patients, the median Injury Severity Score was 27 (interquartile range 17 to 41), and 162 (49%) had a false-negative FAST result. Head injury was positively associated with false-negative FAST result (odds ratio [OR] 4.9; 95% confidence interval [CI] 1.5 to 15.7), whereas severe abdominal injury was negatively associated (OR 0.3; 95% CI 0.1 to 0.5). Injuries to the spleen (OR 0.4; 95% CI 0.24 to 0.66), liver (OR 0.36; 95% CI 0.21 to 0.61), and abdominal vasculature (OR 0.17; 95% CI 0.07 to 0.38) were also negatively associated with false-negative FAST result. False-negative FAST result was not associated with mortality (OR 0.89; 95% CI 0.42 to 1.9), prolonged ICU length of stay (relative risk 0.88; 95% CI 0.69 to 1.12), or total hospital length of stay (relative risk 0.92; 95% CI 0.76 to 1.12). However, patients with false-negative FAST results were substantially less likely to require therapeutic laparotomy (OR 0.31; 95% CI 0.19 to 0.52). CONCLUSION: Patients with severe head injuries and minor abdominal injuries were more likely to have a false-negative than true-positive FAST result. On the other hand, patients with spleen, liver, or abdominal vascular injuries are less likely to have false-negative FAST examination results. Adverse outcomes were not associated with false-negative FAST examination results, and in fact patients with false-negative FAST result were less likely to have a therapeutic laparotomy. Further studies are needed to assess the strength of these findings.

Validation and refinement of a rule to predict emergency intervention in adult trauma patients.

STUDY OBJECTIVE: Trauma centers use "secondary triage" to determine the necessity of trauma surgeon involvement. A clinical decision rule, which includes penetrating injury, an initial systolic blood pressure less than 100 mm Hg, or an initial pulse rate greater than 100 beats/min, was developed to predict which trauma patients require emergency operative intervention or emergency procedural intervention (cricothyroidotomy or thoracotomy) in the emergency department. Our goal was to validate this rule in an adult trauma population and to compare it with the American College of Surgeons' major resuscitation criteria. METHODS: We used Level I trauma center registry data from September 1, 1995, through November 30, 2008. Outcomes were confirmed with blinded abstractors. Sensitivity, specificity, and 95% confidence intervals (CIs) were calculated. RESULTS: Our patient sample included 20,872 individuals. The median Injury Severity Score was 9 (interquartile range 4 to 16), 15.3% of patients had penetrating injuries, 13.5% had a systolic blood pressure less than 100 mm Hg, and 32.5% had a pulse rate greater than 100 beats/min. Emergency operative intervention or procedural intervention was required in 1,099 patients (5.3%; 95% CI 5.0% to 5.6%). The sensitivities and specificities of the rule and the major resuscitation criteria for predicting emergency operative intervention or emergency procedural intervention were 95.6% (95% CI 94.3% to 96.8%) and 56.1% (95% CI 55.4% to 56.8%) and 85.5% (95% CI 83.3% to 87.5%) and 80.9% (95% CI 80.3% to 81.4%), respectively. CONCLUSION: This new rule was more sensitive for predicting the need for emergency operative intervention or emergency procedural intervention directly compared with the American College of Surgeons' major resuscitation criteria, which may improve the effectiveness and efficiency of trauma triage.

Validation of the Simplified Motor Score for the prediction of brain injury outcomes after trauma.

STUDY OBJECTIVE: The Glasgow Coma Scale (GCS) score is widely used in the initial evaluation of patients with traumatic brain injury. This 15-point score, however, has been criticized as unnecessarily complex. Recently, a 3-point Simplified Motor Score (defined as obeys commands=2; localizes pain=1; withdrawals to pain or worse=0) was developed from the motor component of the GCS and was found to have a similar test performance for predicting outcomes after traumatic brain injury when compared with the GCS score as the criterion standard. The purpose of this study was to validate the Simplified Motor Score in a large heterogeneous trauma population. METHODS: This was a secondary analysis of a prospectively maintained trauma registry with consecutive trauma patients who presented to a Level I trauma center from 1995 through 2004. Test performance of the GCS and the Simplified Motor Score relative to 4 clinically relevant traumatic brain injury outcomes (emergency intubation, clinically significant brain injury, neurosurgical intervention, and mortality) was evaluated with areas under the receiver operating characteristic curves (AUCs). RESULTS: Of 21,170 patients included in the analysis, 18% underwent emergency intubation, 14% had clinically significant brain injuries, 7% underwent neurosurgical intervention, and 5% died. The AUCs for the GCS and its components ranged from 0.76 to 0.92 across the 4 outcome measures. The AUCs for the Simplified Motor Score ranged from 0.71 to 0.89, and the relative differences from the GCS AUCs ranged from 3% to 7%, with a median difference of 5%. CONCLUSION: In this external validation study, the 3-point Simplified Motor Score demonstrated similar test performance when compared with the 15-point GCS score and its components for the prediction of 4 clinically important traumatic brain injury outcomes.

An evaluation of out-of-hospital advanced airway management in an urban setting.

OBJECTIVES: To determine the success and complication rates associated with endotracheal intubation in an urban emergency medical services (EMS) system. METHODS: This study evaluated consecutive airway interventions between March 2001 and May 2001 performed by paramedics from the Denver Health Paramedic Division in Denver, Colorado. Patients were identified and enrolled prospectively with the identification of all patients for whom intubation was attempted. A retrospective chart review of the emergency department (ED), intensive care unit, other hospital records, and the coroner's records was then conducted with the intent of identifying all complications related to attempted intubation, including the placement of each endotracheal tube. RESULTS: A total of 278 patients were included in this study. Of these, 154 (55%) had an initial nasal intubation attempt, and 124 (45%) had an initial oral intubation attempt. Of the 278 patients for whom an intubation was attempted, 234 (84%, 95% CI = 77% to 88%) were reported by paramedics to be successfully intubated. Of 114 nasal intubations reported as successful by paramedics, two (2%; 95% CI = 0.2% to 6%) were found to be misplaced. Of the 120 oral intubations reported as successful by paramedics, one (1%; 95% CI = 0.02% to 5%) was found to be misplaced. Of the 278 patients, 22 (8%; 95% CI = 5% to 12%) had complications; three (1%; 95% CI = 0.2% to 3%) endotracheal tubes were incorrectly positioned, two (0.7%; 95% CI = 0.08% to 3%) of which were undetected esophageal intubations and one (0.4%; 95% CI = 0 to 2%) of which was in the posterior pharynx. CONCLUSIONS: Reasonable success and complication rates of endotracheal intubation in the out-of-hospital setting can be achieved in a busy, urban EMS system without the assistance of medications.

Emergency medical vehicle collisions and potential for preventive intervention.

BACKGROUND: Emergency medical vehicle collisions (EMVCs) cause significant injury, death, and property damage every year in the United States and result in significant delays in transporting patients to the hospital. OBJECTIVE: To identify factors associated with EMVCs that are potentially amenable to preventive intervention. METHODS: The authors reviewed data from the Paramedic Division of the Denver Health and Hospital Authority (DHHA) on all EMVCs occurring from 1989 through 1997. RESULTS: A T-bone mechanism, collision at an intersection, and alcohol intoxication of the civilian driver were all significant predictors of collisions resulting in injury (odds ratios of 29.7, 4.3 and 6.1, respectively, p<0.05, multiple logistic regression). Although only 75% of the division's responses are run with warning lights and sirens (WLS), a disproportionate 91% of response mode collisions were during a WLS response. The responsible EMV driver had a history of multiple EMVCs in 71% of the collisions. CONCLUSIONS: Potential interventions suggested by this study include the need for EMV drivers to visually clear the intersection before entering it, alerting other drivers with visual and auditory warning systems, and attempting to make eye contact with them at an intersection. The authors recommend continued public education regarding the risks of drunk driving. The authors feel that the WLS driving mode is best reserved for patients in whom the benefits of shorter response and return times outweigh the risk of collision. Finally, the authors advocate careful review of drivers' collision history, frequent emergency vehicle operator's course retraining, and appropriate discipline when necessary.