Postoperative hemodynamics after high spinal block with or without intrathecal morphine in cardiac surgical patients: a randomized-controlled trial

Abstract

Purpose There is some evidence for the use of intrathecal morphine as a means to provide prolonged analgesia in selective cardiac surgical patients; however, the hemodynamic effects of intrathecal morphine are not well defined. This study was designed to study the effect of intrathecal morphine on hemodynamic parameters in cardiac surgery patients. Methods In a prospective, double-blind study, 100 adult cardiac surgical patients were randomized to receive either intrathecal 40 mg of 0.5% hyperbaric bupivacaine alone (intrathecal bupivacaine [ITB] group, n = 50) or intrathecal 250 lg of morphine added to 40 mg of 0.5% bupivacaine (intrathecal bupivacaine and morphine [ITBM] group, n = 50). Hemodynamic data, pain scores, rescue analgesic use, spirometry, and vasopressor use were recorded every four hours after surgery for 48 hr. The primary outcome was the incidence of vasoplegia in each group, which was defined as a cardiac index [ 2.2 LÁmin -1 Ám -2 with the requirement of vasopressors to maintain the mean arterial pressure [ 60 mmHg with the hemodynamic episode lasting[four hours. Results Eighty-seven patients were analyzed (ITB group, n = 42, and ITBM group, n =45). The incidence of vasoplegia was higher in the ITBM group than in the ITB group [14 (31%) vs 5 (12%), respectively; relative risk, 2.6; 95% confidence interval [CI], 1.0 to 6.6; P = 0.04]. The mean (standard deviation [SD]) duration of vasoplegia was significantly longer in the ITBM group than in the ITB group [8.9 (3.0) hr vs 4.3 (0.4) hr, respectively; difference in means, 4.6; 95% CI, 3.7 to 5.5; P \ 0.001]. Conclusion Intrathecal morphine added to bupivacaine for high spinal anesthesia increases the incidence and duration of vasoplegia in cardiac surgery patients. Trial registration www.clinicaltrials.gov (NCT02825056); registered 19 June 2016.

Analgesic efficacy and risk of low-to-medium dose intrathecal morphine in patients undergoing cardiac surgery: An updated meta-analysis

“…The mean or median age ranged from 25.9 to 67.3 years with a male predominance (>70%, 11 trials). CABG and mixed CABG/valve surgery were performed in eight ( 3 , 31 , 34 – 36 , 39 – 41 ) and four ( 28 , 29 , 33 , 37 ) trials, respectively, while the other three trials were focused on minimally invasive cardiac surgery ( n = 2) ( 30 , 38 ) and valve surgery ( n = 1) ( 32 ). ITM was administered preoperatively in all studies with a maximum dose of 0.5 mg or 7 μg/kg and a minimum dose of 0.25 mg or 0.4 μg/kg.…”

“…ITM was administered preoperatively in all studies with a maximum dose of 0.5 mg or 7 μg/kg and a minimum dose of 0.25 mg or 0.4 μg/kg. Intrathecal morphine was used as a single agent in 12 trials ( 3 , 28 , 30 – 34 , 36 , 38 – 41 ) and as a component of a combined regimen in three studies ( 29 , 35 , 37 ). Patients in the control groups received local anesthesia of the back, no treatment, or placebo (e.g., intrathecal normal saline).…”

Persistent Pain After Cardiac Surgery: Prevention and Management

“…43 Neuraxial anesthesia serves as one regional technique that may be considered in cardiac surgery via thoracic epidural analgesia (TEA) or spinal anesthesia. 16,43,44 TEA has been shown to provide effective analgesia with decreased VAS scoring and reduced opioid consumption postoperatively, 16,27 yet no evidence supports a definitive decrease in developing chronic pain following TEA or intrathecal opioid administration. 27 The risk of spinal hematoma has historically been shown to be 1:1528 for TEA and 1:3610 for spinal anesthesia, 45 but the risk for TEA has more recently been shown to be as low as 1:3552.…”

Year in Review 2021: Noteworthy Literature in Cardiothoracic Anesthesia

“…Another single-center, prospective, randomized, double-blinded trial by Bhat et al investigated intrathecal morphine usage during cardiac surgery in the setting of intrathecal bupivacaine for intentional high spinal. 29 At their institution, spinal blockade up to the T1 dermatome combined with light general anesthesia is frequently used during open cardiac surgery, with the goal of attenuating adrenergic stress and systemic inflammatory response. 30 In seeking to add intrathecal morphine to provide prolonged postoperative analgesia and decrease postoperative pulmonary complications, 31 Bhat et al compared the combination of intrathecal morphine plus bupivacaine (ITBM, 45 patients) vs bupivacaine alone (ITB, 42 patients).…”