Background: Inadequate pain management is common in the Emergency Department (ED). Optimal treatment of pain necessitates titration to effective dose due to the large inter-individual variability in opioid requirement. However nurse administered titration is difficult to provide in this setting due to high patient to nurse and physician ratios and multiple urgent competing patient demands. Patient controlled analgesia (PCA) lets ED patients actively participate in pain management by allowing self-titration to their desired level of pain relief. A tightly controlled randomized clinical trial (RCT) funded by the National Institute of Nursing Research (NINR) recently completed by the investigators group provides promising preliminary support for the efficacy and safety of PCA for patients with abdominal pain at a single ED with a dedicated research nurse and standard loading dose given to all patients. Objective: The overall objective is to provide optimal pain management in the ED. Specific aims: 1)To compare the effectiveness and safety of PCA and non-PCA opioid analgesia when nurses involved in clinical care deliver the intervention to a broad group of ED patients with acute pain at multiple clinical centers. The primary hypothesis is that there will be a greater decline in pain over time and similar safety in patients randomized to receive PCA compared to patients receiving standard opioid analgesia. 2) To describe the feasibility of PCA in terms of patient and provider acceptance, resource utilization and cost associated with PCA. Innovation: PCA represents a novel shift from the current provider-driven model of ED pain management to one in which the patient is an active participant. Few prior studies have evaluated ED PCA and no systematic evaluation of time and resources exists. Methodology: An RCT will be performed at 3 clinical centers. 750 patients with acute pain warranting IV opioid administration will be randomized to receive usual opioid analgesia determined by the provider or PCA (loading dose 0.1 mg/kg morphine and demand dose of 1 mg morphine available every 6 minutes). Pain intensity will be measured by a numerical rating scale (NRS) recorded every half hour up to 2 hours after initial opioid administration. Primary endpoints are rate of change in pain intensity from 30 minutes after initial administration of opioid to 2 hours as suggested by the results of the preliminary study and incidence of adverse events. PCA will also be compared to non-PCA opioid analgesia assessed at the end of the 2 hour study period by patient satisfaction with pain management; registered nurse (RN) assessment of time efficiency/ease of use and satisfaction with pain management; and physician satisfaction with pain management. Resource utilization and cost associated with implementation and use of PCA in the ED setting will be assessed by total Registered nurse (RN) time spent on pain management per patient; pharmacy preparation time per patient; material cost per patient and Registered Nurse and Physician training time necessary for PCA implementation. Significance: If PCA is demonstrated to be effective, safe, and associated with patient and provider acceptance and acceptable resource utilization, it has the potential to significantly improve ED pain management.

Inclusion Criteria:

1. Age 18 to 65
2. Patient deemed by the ED attending physician to require IV opioid analgesia for pain and for whom the ED Attending Physician would consider using PCA

Exclusion Criteria:

1. Patients requiring initial resuscitation that would preclude the use of PCA
2. Long-term use of prescription or non-prescription opioids now or within the past year
3. Recent opioid use within the past 24 hours
4. Chronic pain syndromes
5. Clinician suspicion of current or past opioid dependence/abuse
6. Altered mental status/Clinical suspicion of intoxication
7. Patients expected to require conscious sedation while in the ED
8. Pregnancy or breast-feeding
9. History of chronic obstructive pulmonary disease, history of sleep apnea syndrome, baseline oxygen saturation (room air) < 97%
10. Systolic blood pressure < 100 mm Hg
11. Use of sedative medications e.g. benzodiazepines, monoamine oxidase inhibitors, phenothiazines, or tricyclic antidepressants.
12. History of renal insufficiency/renal failure
13. Prior allergic reaction to morphine
14. Inability to provide informed consent or inability to understand or operate PCA device
15. Previous entry of patient into study

2 hours

Need for oxygen supplementation or ventilatory assistance Hypotension requiring fluid administration or vasopressors Administration of naloxone (an opioid reversal agent) Oxygen saturation measured by pulse oximetry < 92% for one minute or more Respiratory rate <10 breaths/min counted for 60 seconds Systolic blood pressure < 90 mm Hg.

The full benefit of PCA may accrue over a longer period of time than observed during two-hours. Two-hours not be long enough to capture the full benefit of access to re-dosing in response to the diminishing effect of initial analgesic dose over time.