Evaluation of Ultrasound Guided Continuous Interscalene Block for Same Day Discharge Following Total Shoulder Arthroplasty - An Open Label Feasibility Study

The number of shoulder replacement surgeries is increasing over the years and it is expected to continue as the population ages (1). This necessitates adequate pain control in the immediate and early postoperative period when pain levels are typically high. Adequate analgesia ensures patient comfort and the ability to perform physical therapy exercises associated with positive surgical outcomes (2-3). Interscalene brachial plexus block (ISB) is commonly performed to provide analgesia for patients undergoing surgical procedures in the shoulder region. Either single injection blocks or continuous perineural infusions are performed along with oral medications for better pain control in these patients. Compared with intravenous opioids, ISB is known to produce superior analgesia after major shoulder surgery (4,5). There are reports of outpatient TSA discharged directly from the recovery room following the use of continuous ISB but achievement of adequate range of motion were not tested in them (6). Consequently, ambulatory ISB may offer decreased hospitalization while ensuring adequate analgesia after TSA. Ilfeld et al (7) prospectively compared ISB and opioids regarding the time to readiness for discharge following TSA, which was followed by many other studies demonstrating the safety and efficacy of continuous ISB for TSA (8, 9). Ilfeld et al (6) showed that discharge criteria were 21 (16-41) h with the use of ISB as compared to 51 (37-90) h for those receiving perineural normal saline. In our centre, healthy patients requiring shoulder arthroplasty usually remain as in-patients for management of pain. Perineural infusions may be continued at home using a portable infusion pump after discharge. With the use of disposable portable infusion pump for continuous ISB, it may be feasible to discharge patients and reduce hospitalization time.

Although the study by Ilfeld et al showed continuous ISB allowing earlier home discharge following TSA, the patients in the study were evaluated for readiness to discharge on POD1 at 10 AM rather than the earliest times possible. Another interesting finding is that all patients received ropivacaine infusions till 6 AM of POD1 but the authors also claim to have discharged few patients on the same afternoon after the surgery. The block infusions reported in previous studies are higher than used at our institute.

There is also conflicting evidence that although continuous ISB provides adequate analgesia, they seldom impact early functional rehabilitation (10). With this background we want to evaluate the earliest times for the achievement of readiness to discharge with the use of ISB following TSA.