Intrathecal Morphine for Analgesia in Minimally Invasive Cardiac Surgery: A Randomized, Placebo-controlled, Double-blinded Clinical Trial.

BACKGROUND: Intrathecal morphine decreases postoperative pain in standard cardiac surgery. Its safety and effectiveness have not been adequately evaluated in minimally invasive cardiac surgery. The authors hypothesized that intrathecal morphine would decrease postoperative morphine consumption after minimally invasive cardiac surgery. METHODS: In this randomized, placebo-controlled, double-blinded clinical trial, patients undergoing robotic totally endoscopic coronary artery bypass received either intrathecal morphine (5 mcg/kg) or intrathecal saline before surgery. The primary outcome was postoperative morphine equivalent consumption in the first 24 h after surgery; secondary outcomes included pain scores, side effects, and patient satisfaction. Pain was assessed via visual analog scale at 1, 2, 6, 12, 24, and 48 h after intensive care unit arrival. Opioid-related side effects (nausea/vomiting, pruritus, urinary retention, respiratory depression) were assessed daily. Patient satisfaction was evaluated with the Revised American Pain Society Outcome Questionnaire. RESULTS: Seventy-nine patients were randomized to receive intrathecal morphine (n = 37) or intrathecal placebo (n = 42), with 70 analyzed (morphine 33, placebo 37). Intrathecal morphine patients required significantly less median (25th to 75th percentile) morphine equivalents compared to placebo during first postoperative 24 h (28 [16 to 46] mg vs. 59 [41 to 79] mg; difference, -28 [95% CI, -40 to -18]; P < 0.001) and second postoperative 24 h (0 [0 to 2] mg vs. 5 [0 to 6] mg; difference, -3.3 [95% CI, -5 to 0]; P < 0.001), exhibited significantly lower visual analog scale pain scores at rest and cough at all postoperative timepoints (overall treatment effect, -4.1 [95% CI, -4.9 to -3.3] and -4.7 [95% CI, -5.5 to -3.9], respectively; P < 0.001), and percent time in severe pain (10 [0 to 40] vs. 40 [20 to 70]; P = 0.003) during the postoperative period. Mild nausea was more common in the intrathecal morphine group (36% vs. 8%; P = 0.004). CONCLUSIONS: When given before induction of anesthesia for totally endoscopic coronary artery bypass, intrathecal morphine decreases use of postoperative opioids and produces significant postoperative analgesia for 48 h.

Intraoperative Use of Nondepolarizing Neuromuscular Blocking Agents During Cardiac Surgery and Postoperative Pulmonary Complications: A Prospective Randomized Trial.

OBJECTIVE: Nondepolarizing neuromuscular blocking agents (NMBAs) are associated with perioperative complications in noncardiac surgery; however, little is known about their effect on cardiac surgery. This study assessed the effect of neuromuscular blockade (NMB) on the incidence of postoperative pulmonary complications (PPCs) after cardiac surgery and operating conditions. DESIGN: Prospective, randomized clinical trial with blinded outcomes assessment. SETTING: University hospital, single institution. PARTICIPANTS: Adult patients having cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS: One hundred patients were randomized to receive succinylcholine (group SUX) for intubation with no further NMB administered or cisatracurium (group CIS) for intubation and maintenance NMB. The primary outcome was a composite incidence of PPCs in the 72 hours after elective cardiac surgery. PPCs included failure to extubate within 24 hours, need for reintubation, pneumonia, aspiration, unanticipated need for noninvasive respiratory support, acute respiratory distress, and mortality from respiratory arrest. The secondary outcome was the adequacy of operating conditions as assessed by blinded surgeon survey (including a rating of surgical conditions on a Likert scale from 1 = poor to 5 = excellent), anesthesiologist report, and patient questionnaire. MEASUREMENTS AND MAIN RESULTS: The composite incidence of PPCs did not differ between groups (8 of 50 patients in both groups; 16%). Mean surgeon rating of surgical conditions was lower in the SUX group (4.65 ± 0.85 v 4.96 ± 0.20, p = 0.02). CONCLUSION: Although avoiding nondepolarizing NMBA is feasible, doing so worsened operating conditions and did not reduce the incidence of postoperative pulmonary complications.