Comparison of perioperative analgesia and hypotension between pre-surgical bolus morphine followed by 0.0625% bupivacaine with morphine infusion and 0.25% bupivacaine infusion plus postsurgical bolus morphine via thoracic epidural catheter in patients

Abstract

Background: The higher concentration of local anesthetic drug via thoracic epidural catheter may provide more effective pain relief, but also cause more often episodes of hypotension than the lower concentration. This study aimed to compare the effectiveness of perioperative analgesia and the incidence of hypotension between the group of patients who received pre-surgical bolus morphine plus 0.0625% bupivacaine with morphine infusion versus 0.25% bupivacaine infusion plus postsurgical bolus morphine via thoracic epidural route.

Methods: In this prospective double blind randomized controlled trial study, seventy-nine patients who underwent combined general and thoracic epidural anesthesia for abdominal surgery were allocated into two groups : Group A received bolus dose of morphine 3 mg (for age <70 years old) or 2 mg (for age ≥ 70 years old) via epidural catheter before surgical incision followed by 0.0625%bupivacaine with morphine 0.02 mg/ml epidural infusion. Group B received 0.25%bupivacaine for epidural infusion followed by morphine 3 mg (for age <70 years old) or 2 mg (for age ≥ 70 years old) bolus via epidural catheter 30 minutes before operation finished. Intraoperative outcomes included blood pressure, total amount of fentanyl, propofol and vasopressor(ephedrine and levophed), total fluid intake and output. Postoperative outcomes included numerical pain scales and blood pressure in post anesthesia care unit (PACU). 

Results: There were no significant differences in demographic variables, either amount of fentanyl, propofol, or any vasopressor including fluid intake and output. The incidence of moderate to severe pain in PACU were 33.3% in group A and 40% in group B(P= 0.53). The incidence of hypotension during surgery were 61.5% in group A and 62.5% in group B(P =0.93), hypotension in PACU were 25.6% in group A , 22.5% in group B(P= 0.71) 

Conclusion: Perioperative analgesia and incidences of hypotension were not different between these two regimens.