Acetaminophen, Morphine, Fentanyl, Bupivacaine Combination Anesthesia for Cesarean Delivery

An analgesic cocktail with acetaminophen, morphine, fentanyl, and bupivacaine was found to be similarly efficient as intrathecal fentanyl or sufentanil as anesthesia during cesarean section, according to the results of a study published in Current Therapeutic Research.

This randomized, double-blind, controlled trial was conducted at the Hafez Hospital in Iran in 2020. Women (N=105) aged between 20 and 30 years and scheduled for cesarean delivery were randomly assigned to receive 10 mg of 0.5% intrathecal bupivacaine, 2 mg of sufentanil, and saline (group 1; n=35); 10 mg of 0.5% intrathecal bupivacaine, 10 mg of fentanyl, and saline (group 2; n=35); or 10 mg of 0.5% intrathecal bupivacaine and intravenous administration of 1 g of acetaminophen, 5 mg of morphine, and 100 mg of fentanyl diluted in saline (group 3; n=35). The authors state that their “key objective was to determine the best adjuvant for intrathecal bupivacaine in terms of spinal anesthesia quality, pain control, and postoperative side effects.”  The primary outcomes were time of sensory block onset and duration, degree and time of motor block, and pain intensity.

The mean ages of women in groups 1, 2, and 3 were 31.28, 31.60, and 32.02 years; mean body mass index values were 30.11, 31.95, and 30.13 kg/m²; and mean arterial pressures were 98.39, 95.90, and 95.54 mm Hg, respectively.

The spinal block was successful for all patients.

The 3 cohorts did not differ significantly for time to sensory block onset (P =.181), duration of sensory block (P =.401), and duration of motor block (P =.597).

Groups 1 (median, 1.50 min) and 3 (median, 2 min) demonstrated a faster time to motor block onset than group 2 (median, 5 min; both P <.0001), group 1 had a faster time to peak motor bock (median, 4 min) compared with groups 2 and 3 (median, 7 min; both P <.0001), group 1 had a faster time to peak sensory block (median, 3 min) compared with group 2 (median, 4 min; P =.049), more patients in group 3 had successful dermatologic sensory block at T4 (86%) compared with patients in group 1 (60%; P =.032), and more patients in group 1 had successful dermatologic sensory block at T6 (40%) compared with patients in group 3 (14%; P =.022).

Pain scores differed significantly at 5 minutes among groups 1 and 3 (P =.034) and at the end of surgery between groups 1 and 2 (P =.012).In the recovery room, all groups differed significantly for pain scores (P <.001), with group 2 demonstrating lower pain scores than other groups at the later time points.

Mean arterial pressures differed significantly between groups 1 and 2 at 20 minutes (P =.016) and between groups 2 and 3 at 25 minutes (P =.042), 35 minutes (P =.031), and 60 minutes (P =.026).

Patients in group 1 experienced more nausea and vomiting (P <.0001) and less vasopressor requirement (P =.0004) compared with patients in the other groups.

This study may have been limited by not including a patient-controlled analgesic intervention.

These data indicate that during cesarean delivery, an analgesic cocktail with acetaminophen, morphine, fentanyl, and bupivacaine had similar sensory and motor block effects as other analgesic combinations but that bupivacaine with fentanyl provided superior pain control during recovery.