We found no evidence of a beneficial effect of fibrinolysis in patients with cardiac arrest and pulseless electrical activity of unknown or presumed cardiovascular cause. Our study had limited statistical power, and it remains unknown whether there is a small treatment effect or whether selected subgroups may benefit.

Objective: To determine whether naloxone administered IV to out-of-hospital patients with suspected opioid overdose would have a more rapid therapeutic onset than naloxone given subcutaneously (SQ). Methods: A prospective, sequential, observational cohort study of 196 consecutive patients with suspected opioid overdose was conducted in an urban out-of-hospital setting, comparing time intervals from arrival at the patient's side to development of a respiratory rate 2 1 0 breathdmin, and durations of bag-valve-mask ventilation. Subjects received either naloxone 0.4 mg IV (n = 74) or naloxone 0.8 mg SQ (n = 122). for respiratory depression of < l o breathdmin. Results: Mean interval from crew arrival to respiratory rate 2 1 0 breathdmin was 9.3 2 4.2 min for the IV group vs 9.6 & 4.58 min for the SQ group (95% CI of the difference -1.55. 1.00). Mean duration of bagvalve-mask ventilation was 8.1 & 6.0 min for the IV group vs 9.1 _+ 4.8 min for the SQ group. Cost of materials for administering naloxone 0.4 mg IV was $12.30/patient, compared with $10.7O/patient for naloxone 0.8 mg SQ. Conclusion: There was no clinical difference in the time interval to respiratory rate 2 10 breathdmin between naloxone 0.8 mg SQ and naloxone 0.4 mg IV for the out-of-hospital management of patients with suspected opioid overdose. The slower rate of absorption via the SQ route was offset by the delay in establishing an IV.

Abstract. Objective: To develop a clinical prediction rule to identify patients who can be safely discharged one hour after the administration of naloxone for presumed opioid overdose. Methods: Patients who received naloxone for known or presumed opioid overdose were formally evaluated one hour later for multiple potential predictor variables. Patients were classified into two groups: those with adverse events within 24 hours and those without. Using classification and regression tree methodology, a decision rule was developed to predict safe discharge. Results: Clinical findings from 573 patients allowed us to develop a clinical prediction rule with a sensitivity of 99% (95% CI = 96% to 100%) and a specificity of 40% (95% CI = 36% to 45%). Patients with presumed opioid overdose can be safely discharged one hour after naloxone administration if they: 1) can mobilize as usual; 2) have oxygen saturation on room air of >92%; 3) have a respiratory rate >10 breaths/min and <20 breaths/min; 4) have a temperature of >35.0ЊC and <37.5ЊC; 5) have a heart rate >50 beats/min and <100 beats/min; and 6) have a Glasgow Coma Scale score of 15. Conclusions: This prediction rule for safe early discharge of patients with presumed opioid overdose performs well in this derivation set but requires validation followed by confirmation of safe implementation.