Continuous Interscalene Block Results in Superior Recovery Throughout the First Postoperative Week

Background The advantages of single injection (SISB) and continuous interscalene brachial plexus block (CISB) over general anesthesia (GA) only have been previously reported. However, few studies extended their observations beyond 48 postoperative hours, and no study has compared the effects of SISB and CISB as sole anesthesia modalities with GA only. We undertook this randomized trial to compare the recovery profile of patients receiving SISB, CISB or GA for arthroscopic rotator cuff repair surgery through the first postoperative week. Our primary hypothesis was that highest NRS pain rating (worst pain score) at the end of the study week is lower for patients in the CISB group than for patients in the SISB or GA groups.

Methods After Institutional Review Board approval and informed consents were obtained, 71 patients of American Society of Anesthesiologists (ASA) physical status I-III, ≥18 years of age, and BMI≤35 kg/m2, scheduled for elective outpatient arthroscopic rotator cuff repair, were enrolled. CISB patients received 20 mL of 0.5% ropivacaine as bolus through the catheter whereas SISB patients received the same volume of injection through a needle. CISB patients received an infusion of 0.2% ropivacaine at 5mL/h with a patient controlled bolus of 5 mL hourly. GA only patients received a standardized general anesthetic. All patients were prescribed acetaminophen (500mg) with hydrocodone (7.5mg) every 4h as needed. CISB was discontinued 48 h after surgery. Postoperative highest pain scores (NRS) through the first postoperative week, time-to-first pain, analgesic consumption, fast-tracked postoperative care unit (PACU) bypass rate, length of PACU stay, time-to-discharge home, sleep duration, and related adverse effects were recorded in the PACU and at home on postoperative days 1, 2, 3, and 7.

Inclusion criteria

American Society of Anesthesiologists (ASA) physical status I-III patients

≥ 18 years of age BMI ≤ 35 kg/m2 Scheduled for elective arthroscopic shoulder surgery

Exclusion criteria

Patients who were undertaken open shoulder procedures Patients with difficulty understanding the instructions for using the anesthetic infusion pump and/or pain scales Patients with contraindications to regional anesthesia (e.g., allergy to a local anesthetic (LA), local infection, coagulopathy) Patients with significant neurologic disorders of the upper extremity, psychiatric or cognitive disorders, history of substance abuse or chronic opioid use