Faculty Bibliography

BACKGROUND: In the urban setting, hypothermia is commonly associated with illness or intoxication, with death often secondary to infection. OBJECTIVES: To evaluate factors that affect the rewarming rate (RWR) and the ability of the RWR and other clinical markers to predict the presence or absence of underlying infection in an adult urban population. METHODS: This was a prospective observational study of hypothermic patient visits to a large emergency department. Serial temperatures were obtained during rewarming to construct rewarming curves. Rewarming modalities selected by emergency physicians were correlated with admission temperatures. Univariate associates of RWR and infection were assessed. RESULTS: The authors identified 96 patient visits. The median temperature was 89.5 degrees F (31.9 degrees C; range, 73.0 degrees F to 95.0 degrees F [22.8 degrees C to 35.0 degrees C]). Thirteen patients had temperatures of < 80.0 degrees F (26.0 degrees C). Seven died within 14 hours of presentation; six, of infection. No patient experienced ventricular fibrillation. Potential candidate predictors of infection from a multivariate analysis were a RWR of < 1.80 degrees F (1.0 degrees C) per hour and a serum albumin of < 2.7 g/dL. Rapid rewarming was associated with the absence of infection and a temperature below 86.0 degrees F (30.0 degrees C). In patients without significant underlying illness, rewarming rates appeared to be independent of the modality of rewarming. CONCLUSIONS: Rewarming rates reflect intrinsic capacity for thermogenesis. Increased RWRs were associated with the absence of infection. The achievement of normothermia did not prevent death in infected patients. Initiation of invasive rewarming in urban patients with hypothermia who have not had hypothermic cardiac arrest may be unwarranted. Management of this population should emphasize support, detection, and treatment of underlying illness

BACKGROUND AND PURPOSE: Following publication of concerns about the results of the National Institute of Neurological Disorders and Stroke (NINDS) intravenous tissue plasminogen activator (t-PA) in acute stroke treatment trial, NINDS commissioned an independent committee "to address whether there is concern that eligible stroke patients may not benefit from t-PA given according to the protocol used in the trials and, whether the subgroup imbalance (in baseline stroke severity) invalidates the entire trial." METHODS: The original NINDS trial data were reanalyzed to assess the t-PA treatment effect, the effect of the baseline imbalance in stroke severity between the treatment groups on the t-PA treatment effect, and whether subgroups of patients did not benefit from receiving t-PA. RESULTS: A clinically important and statistically significant benefit of t-PA therapy was identified despite subgroup imbalances in baseline stroke severity and an increased incidence of symptomatic intracerebral hemorrhage in t-PA treated patients. The adjusted t-PA to placebo odds ratio (OR) of a favorable outcome was 2.1 (95% CI, 1.5 to 2.9). Although these exploratory analyses found no statistical evidence that the t-PA treatment effect differed among patient subgroups, the study was not powered to detect subgroup treatment differences. CONCLUSIONS: These findings support the use of t-PA to treat patients with acute ischemic stroke within 3 hours of onset under the NINDS t-PA trial protocol. Health professionals should work collaboratively to develop guidelines to ensure appropriate use of t-PA in acute ischemic stroke patients.