Emerging techniques for postoperative analgesia in orthopedic surgery

The current use of multimodal analgesia for the management of postoperative pain has resulted in reduced side effects and improved pain relief. Limitations of the technology associated with current pump- or catheter-based systems have prompted the development of continuous delivery systems and extended-duration techniques for pain relief. Among these are morphine sulfate sustained-release liposome injection (Morphine SR, DepoMorphine) and the patient-controlled transdermal system (PCTS, E-TRANS). Morphine SR utilizes the novel DepoFoam technology, a novel delivery system that allows the drug to be gradually released into the surrounding epidural space. Morphine SR is compatible with anticoagulation therapy and eliminates interference from pump and intravenous (IV) equipment. Administration of Morphine SR during hip arthroplasty significantly reduced patients' postoperative consumption of fentanyl. E-TRANS fentanyl PCTS is a transdermal system attached to the patient's arm or upper chest; a button on the device is controlled by the patient to deliver doses of fentanyl. In a study comparing fentanyl HCl PCTS with conventional IV-patient-controlled analgesia (PCA) morphine, PCTS was found to be as safe and effective as PCA for the treatment of postoperative pain. Novel delivery systems that are less invasive, that are compatible with anticoagulation regimens, and that provide continuous delivery, thus preventing analgesic gaps, will facilitate rehabilitation and recovery and ultimately improve patient outcomes.