Clinical Outcomes From Nalmefene (COINED)

Normalization of the end tidal carbon dioxide value (if measured) to between 35 and 45 mmHg and/or ≥5 breaths per minute increase in respiratory rate from baseline (pre-dose) measurement, with rate of at least 12 breaths per minute.

Increased end tidal carbon dioxide value (if measured) above 45 mmHg when previously within the normal range and/or ≥5 breaths per minute decrease in respiratory rate from maximum post-reversal measurement, with a rate of at most 12 breaths per minute.

One of the following will apply: ED Discharge Hospital Admission ICU Admission Left against medical advice Transfer to another facility Death.

Dose administered for each opioid antagonist given to patients during their ED encounter - Individual dose amount and frequency Cumulative dose Any pre-hospital naloxone given prior to ED arrival - Dose amount, route

This is a single-item instrument used to quickly assess the degree of patient alertness and agitation in emergency and critical care settings. It is an observational assessment conducted by healthcare providers, and it can be completed in seconds. The scale uses integers from -5 to +4, each with its own clear anchor. A score of 0 means that the patient is alert and calm. Negative integers indicate diminished responsiveness and consciousness, with -1 indicating that a patient will open their eyes or make eye contact for 10 or more seconds when awakened by voice, and -5 meaning that the patient is unarousable by voice or physical stimulation. Positive integers indicate an increased level of arousal or agitation. The positive end of the scale spans from +1 (anxious, apprehensive, but not aggressive) to +4 (combative, violent, danger to staff).

This is an observational assessment performed by a clinician to diagnose and assess the severity of opioid withdrawal symptoms. Eleven different opioid withdrawal symptoms are included in the COWS. The clinician will score the presence and severity of each symptom, with 0 indicating that the symptom is absent and more severe symptoms warranting a higher score. Individual symptom scores are then added to determine the overall severity of the patient's withdrawal. Total scores range from 5 to 48 where 5 - 12 = mild; 13 - 24 = moderate; 25 - 36 moderately severe; and greater than 36 = severe withdrawal.

Pulse oximetry monitoring will be used to assess the patient's oxygen saturation level (SpO2), expressed as a percentage from 0 to 100.

Defined as the difference between time at Triage to time at ED Disposition