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

Abstract

BackgroundTo evaluate the analgesic efficacy and risk of low-to-medium dose intrathecal morphine (ITM) (i.e., ≤0.5 mg) following cardiac surgery.MethodsMedline, Cochrane Library, Google scholar and EMBASE databases were searched from inception to February 2022. The primary outcome was pain intensity at postoperative 24 h, while the secondary outcomes included intravenous morphine consumption (IMC), extubation time, hospital/intensive care unit (ICU) length of stay (LOS), and ITM-associated side effects (e.g., respiratory depression). Subgroup analysis was performed on ITM dosage (low: <0.3 mg vs. medium: 0.3–0.5 mg).ResultsFifteen RCTs involving 683 patients published from 1988 to 2021 were included. Pooled results showed significantly lower postoperative 24-h pain scores [mean difference (MD) = −1.61, 95% confidence interval: −1.98 to −1.24, p < 0.00001; trial sequential analysis: sufficient evidence; certainty of evidence: moderate] in the ITM group compared to the controls. Similar positive findings were noted at 12 (MD = −2.1) and 48 h (MD = −1.88). Use of ITM was also associated with lower IMC at 24 and 48 h (MD: −13.69 and −14.57 mg, respectively; all p < 0.05) and early tracheal extubation (i.e., 48.08 min). No difference was noted in hospital/ICU LOS, and nausea/vomiting in both groups, but patients receiving ITM had higher risk of pruritus (relative risk = 2.88, p = 0.008). There was no subgroup difference in IMC except a lower pain score with 0.3–0.5 mg than <0.3 mg at postoperative 24 h. Respiratory depression events were not noted in the ITM group.ConclusionOur results validated the analgesic efficacy of low-to-medium dose ITM for patients receiving cardiac surgery without increasing the risk of respiratory depression.

Practice Advisory for Preoperative and Intraoperative Pain Management of Cardiac Surgical Patients: Part 2

“…164 A meta-analysis also reported reduced pain scores at 24 hours after cardiac surgery with IT morphine use (category A1-B evidence). 165 However, a higher risk of pruritus was reported in these patients as a secondary outcome compared to controls. 165 Summary and Recommendations.…”

“…165 However, a higher risk of pruritus was reported in these patients as a secondary outcome compared to controls. 165…”

“…165 However, a higher risk of pruritus was reported in these patients as a secondary outcome compared to controls. 165 Summary and Recommendations. Although TEA in cardiac surgery offers superior pain control, its routine use is not recommended due to potentially devastating complications in patients with full anticoagulation or at risk for hemodynamic instability (recommendation www.anesthesia-analgesia.org…”

Impact of intravenous vitamin C as a monotherapy on mortality risk in critically ill patients: A meta-analysis of randomized controlled trials with trial sequential analysis

“…To assess the strength of the results and to guard against statistical errors of type I and type II, we performed trial sequential analysis (TSA) as previously described ( 25 , 26 ). We calculated the diversity-adjusted information size using 80% power while maintaining an overall two-sided type I error of 5%.…”

Regional Anesthesia for Cardiac Surgery

“…Another group found intrathecal morphine administered prior to minimally invasive cardiac surgery decreased visual analog pain scores and intravenous opiate usage post-operatively [22]. A meta-analysis of intrathecal morphine compared to general anesthesia alone in cardiac surgical patients also found decreases in pain scores and post-operative opiate use at the expense of increased pruritis [23].…”