Opioids added to local anesthetics for single-shot intrathecal anesthesia in patients undergoing minor surgery: A meta-analysis of randomized trials

Abstract

a b s t r a c tOpioids are widely used as additives to local anesthetics for intrathecal anesthesia. Benefit and risk remain unclear. We systematically searched databases and bibliographies to February 2011 for full reports of randomized comparisons of any opioid added to any intrathecal local anesthetic with the local anesthetic alone in adults undergoing surgery (except cesarean section) and receiving single-shot intrathecal anesthesia without general anesthesia. We included 65 trials (3338 patients, 1932 of whom received opioids) published between 1983 and 2010. Morphine (0.05-2 mg) and fentanyl (10-50 lg) added to bupivacaine were the most frequently tested. Duration of postoperative analgesia was prolonged with morphine (weighted mean difference 503 min; 95% confidence interval [CI] 315 to 641) and fentanyl (weighted mean difference 114 min; 95% CI 60 to 168). Morphine decreased the number of patients needing opioid analgesia after surgery and decreased pain intensity to the 12th postoperative hour. Morphine increased the risk of nausea (number needed to harm [NNH] 9.9), vomiting (NNH 10), urinary retention (NNH 6.5), and pruritus (NNH 4.4). Fentanyl increased the risk of pruritus (NNH 3.3). With morphine 0.05 to 0.5 mg, the NNH for respiratory depression varied between 38 and 59 depending on the definition of respiratory depression chosen. With fentanyl 10 to 40 lg, the risk of respiratory depression was not significantly increased. For none of these effects, beneficial or harmful, was there evidence of dose-responsiveness. Consequently, minimal effective doses of intrathecal morphine and fentanyl should be sought. For intrathecal buprenorphine, diamorphine, hydromorphone, meperidine, methadone, pentazocine, sufentanil, and tramadol, there were not enough data to allow for meaningful conclusions.Ó

Comparison of effect of intrathecal dexmedetomidine and clonidine as an adjuvant to hyperbaric bupivacaine in patients undergoing surgery for fracture femur and tibia

“…1,3 Other classes of drugs such as epinephrine, midazolam, neostigmine, ketamine, magnesium and clonidine have been added to the intrathecal local anaesthetics to prolong the analgesic effect and to reduce the incidence of adverse events. [4][5][6][7] These opioids produce satisfactory analgesia for 24hours postoperatively, but are frequently associated with side effects like respiratory depression, itching, nausea, vomiting and urinary retention. [8][9][10][11][12] Other adjuvants like ketamine, neostigmine has been tried but none has become established in regular clinical practice.…”

İnguinal herni tamiri sonrası postoperatif ağrı üzerinde intratekal fentanil ve intratekal morfinin etkilerinin karşılaştırılması

“…However, minimal effective doses of intrathecal morphine and fentanyl are still a research topic. Furthermore, there is no clear evidence of dose-responsiveness for benefit and risk 6 . The low hydrophobicity of morphine may be responsible for its slow clearance into the systemic circulation and long duration 8 .…”

“…IT morphine can produce a long-lasting postoperative pain relief 6 . However, it can be limited to use due to its side effects including nausea, vomiting, pruritus, respiratory depression, and urinary retention 6,7 . The incidence of respiratory depression with fentanyl may not increase significantly despite an increased risk of pruritus 6 .…”

“…However, it can be limited to use due to its side effects including nausea, vomiting, pruritus, respiratory depression, and urinary retention 6,7 . The incidence of respiratory depression with fentanyl may not increase significantly despite an increased risk of pruritus 6 . Nevertheless, there is no study comparing morphine and fentanyl added to a local anesthetic for postoperative pain control with spinal anesthesia in IHR.…”

Epidural volume extension in combined spinal‐epidural anaesthesia

“…It is possible that EVE has a negligible effect on spinal block height and other characteristics compared with these factors. This is indirectly supported by the fact that few studies suggest an EVE effect (even with close to 10 ml EVE) on the height and duration of block in parturients undergoing spinal anaesthesia [4][5][6]. Moreover, even when EVE with saline significantly raised the sensory level in one study, it did not reduce the need for intra-operative supplementation nor increase the success rate of spinal anaesthesia [7].…”