Interscalene Brachial Plexus Block with Liposomal Bupivacaine versus Standard Bupivacaine with Perineural Dexamethasone: A Noninferiority Trial.

BACKGROUND: The interscalene nerve block provides analgesia for shoulder surgery. To extend block duration, provide adequate analgesia, and minimize opioid consumption, the use of adjuvants such as dexamethasone as well as the application of perineural liposomal bupivacaine have been proposed. This randomized, double-blinded, noninferiority trial hypothesized that perineural liposomal bupivacaine is noninferior to standard bupivacaine with perineural dexamethasone in respect to average pain scores in the first 72 h after surgery. METHODS: A total of 112 patients undergoing ambulatory shoulder surgery were randomized into two groups. The liposomal bupivacaine group received a 15-ml premixed admixture of 10 ml of 133 mg liposomal bupivacaine and 5 ml of 0.5% bupivacaine (n = 55), while the bupivacaine with dexamethasone group received an admixture of 15 ml of 0.5% standard bupivacaine with 4 mg dexamethasone (n = 56), respectively. The primary outcome was the average numerical rating scale pain scores at rest over 72 h. The mean difference between the two groups was compared against a noninferiority margin of 1.3. Secondary outcomes were analgesic block duration, motor and sensory resolution, opioid consumption, numerical rating scale pain scores at rest and movement on postoperative days 1 to 4 and again on postoperative day 7, patient satisfaction, readiness for postanesthesia care unit discharge, and adverse events. RESULTS: A liposomal bupivacaine group average numerical rating scale pain score over 72 h was not inferior to the bupivacaine with dexamethasone group (mean [SD], 2.4 [1.9] vs. 3.4 [1.9]; mean difference [95% CI], -1.1 [-1.8, -0.4]; P < 0.001 for noninferiority). There was no significant difference in duration of analgesia between the groups (26 [20, 42] h vs. 27 [20, 39] h; P = 0.851). Motor and sensory resolutions were similar in both groups: 27 (21, 48) h versus 27 (19, 40) h (P = 0.436) and 27 [21, 44] h versus 31 (20, 42) h (P = 0.862), respectively. There was no difference in opioid consumption, readiness for postanesthesia care unit discharge, or adverse events. CONCLUSIONS: Interscalene nerve blocks with perineural liposomal bupivacaine provided effective analgesia similar to the perineural standard bupivacaine with dexamethasone. The results show that bupivacaine with dexamethasone can be used interchangeably with liposomal bupivacaine for analgesia after shoulder surgery.

Superior Trunk Block: A Phrenic-sparing Alternative to the Interscalene Block: A Randomized Controlled Trial.

BACKGROUND: Interscalene nerve blockade remains one of the most commonly used anesthetic and analgesic approaches for shoulder surgery. The high incidence of hemidiaphragmatic paralysis associated with the block, however, precludes its use among patients with compromised pulmonary function. To address this issue, recent studies have investigated phrenic-sparing alternatives that provide analgesia. None, however, have been able to reliably demonstrate surgical anesthesia without significant risk for hemidiaphragmatic paralysis. The utility of the superior trunk block has yet to be studied. The hypothesis was that compared with the interscalene block, the superior trunk block will provide noninferior surgical anesthesia and analgesia while sparing the phrenic nerve. METHODS: This randomized controlled trial included 126 patients undergoing arthroscopic ambulatory shoulder surgery. Patients either received a superior trunk block (n = 63) or an interscalene block (n = 63). The primary outcomes were the incidence of hemidiaphragmatic paralysis and worst pain score in the recovery room. Ultrasound was used to assess for hemidiaphragmatic paralysis. Secondary outcomes included noninvasively measured parameters of respiratory function, opioid consumption, handgrip strength, adverse effects, and patient satisfaction. RESULTS: The superior trunk group had a significantly lower incidence of hemidiaphragmatic paralysis compared with the interscalene group (3 of 62 [4.8%] vs. 45 of 63 [71.4%]; P < 0.001, adjusted odds ratio 0.02 [95% CI, 0.01, 0.07]), whereas the worst pain scores in the recovery room were noninferior (0 [0, 2] vs. 0 [0, 3]; P = 0.951). The superior trunk group were more satisfied, had unaffected respiratory parameters, and had a lower incidence of hoarseness. No difference in handgrip strength or opioid consumption were detected. Superior trunk block was associated with lower worst pain scores on postoperative day 1. CONCLUSIONS: Compared with the interscalene block, the superior trunk block provides noninferior surgical anesthesia while preserving diaphragmatic function. The superior trunk block may therefore be considered an alternative to traditional interscalene block for shoulder surgery.

Hypotensive epidural anesthesia in patients with aortic stenosis undergoing total hip replacement.

BACKGROUND AND OBJECTIVES: The use of conduction anesthesia and induced hypotension are traditionally contraindicated in patients with aortic stenosis. This hypothesis-generating observational pilot study details the clinical outcomes in patients with aortic stenosis undergoing hypotensive epidural anesthesia for total hip replacement. METHODS: From a database of 1,947 consecutive patients undergoing total hip replacement under hypotensive epidural anesthesia performed from 1994 to 2005, 22 patients were identified with aortic stenosis. Chart review was performed. All patients were monitored with central venous pressure and radial arterial catheters. Cardiovascular and renal outcomes, thromboembolic events, and blood loss and transfusion were assessed. RESULTS: Twenty-two patients were identified: 19 patients (86%) were American Society of Anesthesiologists classification III, and 3 patients (14%) were American Society of Anesthesiologists classification IV. The mean age was 75 years (range: 58-92). No patient suffered from preoperative angina, syncope, or resting dyspnea. Valve areas ranged from 0.9 to 1.8 cm(2) and peak gradient from 12 to 64 mm Hg. Systolic blood pressure was maintained at 60 to 100 mm Hg. The mean duration of hypotension was 91 minutes (range: 50-200). Heart rate was maintained at a mean (+/-SD) of 70 +/- 11. Central venous pressure was maintained at baseline value. Mean intraoperative crystalloid administered was 1,695 mL (range: 900-4,000), and mean estimated blood loss was 234 mL (range: 100-1,500). There were no deaths, myocardial infarctions, cerebrovascular accidents, or pulmonary embolic events. No patient developed renal dysfunction. CONCLUSIONS: We report the absence of complications (with calculated upper limit 95% confidence interval of approximately 13.6%) when hypotensive epidural anesthesia was performed in 22 patients with noncritical asymptomatic aortic stenosis.