A prospective randomized trial of nebulized morphine compared with patient-controlled analgesia morphine in the management of acute thoracic pain.

Background: Successfully managing pain for the trauma patient decreases morbidity, improves patient satisfaction, and is an essential component of critical care. Using patient-controlled analgesia (PCA) morphine to control pain may be complicated by concerns of respiratory depression, hemodynamic instability, addiction, urinary retention, and drug-induced ileus. Morphine is rapidly absorbed by mucosal surfaces in the respiratory tract, achieving systemic concentrations equal to 20% of equivalent intravenous doses. The purpose of this study was to evaluate the safety, efficacy, and utility of nebulized morphine in patients with posttraumatic thoracic pain.

Methods: This double-blinded, prospective study randomized patients with severe posttraumatic thoracic pain into two groups. The experimental group (NMS) received nebulized morphine every 4 hours and normal saline by PCA. The control group (PCA) received nebulized saline every 4 hours and morphine by PCA. Dose adjustments were made based on patient response to treatments using a 10-point visual analog scale (VAS) for pain. Pulmonary function, pain relief (VAS), level of sedation (0-3), total drug administration, and systematic side effects were recorded.

Results: Forty-four patients were randomized (22 per group). Seven hundred seventy observations were made. The mean 4-hour dose of morphine was 11.96 +/- 3.4 mg for NMS and 6.22 +/- 4.7 mg for PCA (p < 0.001). Patients with NMS had lower heart rates compared with PCA (79 +/- 11 bpm versus 92 +/- 12 bpm; p < 0.001) and were less sedated (0.33 +/- 0.7 versus 0.56 +/- 0.9; p = 0.03). The mean pain level (VAS) was 3.38 +/- 1.8 for NMS and 3.84 +/- 2.7 for PCA (p = 0.2). There was no difference between pain levels before and after dosing. There were no differences between groups with respect to arterial blood pressure, respiratory rate, vital capacity, mean forced expiratory volume in 1 second, spirometric volumes, or Sao2.

Conclusion: Nebulized morphine can be safely and effectively used to control posttraumatic thoracic pain. Pain can be successfully managed while vital capacity, mean forced expiratory volume in one second, and spirometric volumes are maintained. Compared with PCA morphine, nebulized morphine provides equivalent pain relief with less sedative effects.