Objective:

In this study, the aim was to compare the effects of epidural fentanyl and morphine on postoperative pain as well as their hemodynamic responses and complications in patients who are planned to undergo major lower abdominal surgery with general anesthesia. These two different opioids are added to epidural levobupivacaine and administered together with general anesthesia.

Material and Methods:

The study patients were randomly divided into two groups as Group F (Levobupivacaine + Fentanyl) and Group M (Levobupivacaine + Morphine). After the catheter was introduced at the L3-4 or L4-5 epidural space, 0.5 % Levobupivacaine + 2 μg ml-1 Fentanyl mixture was administered to the patients in Group F and 0.5 % Levobupivacaine + 0.1 mg ml-1 Morphine mixture was administered to the patients in Group M. Loading dose was 0.1 cc kg-1 and it was administered through the catheter. When sensorial block reached to T6 dermatome, the patients were anaesthetized through propofol, cisatracrium and fentanyl induction. Airway management was provided by ProSeal LMA. In the peroperative period, using continuous infusions through an epidural catheter connected to the PCA device, 0.25 % Levobupivacaine + 2 μg ml-1 Fentanyl 5 ml h-1 was administered to Group F patients. Group M patients were given 0.25 % Levobupivacaine 5 ml h-1 and, morphine 0.1 mg h-1. In the postoperative period, 0.125 % Levobupivacaine + 2 μg ml-1 Fentanyl mixture was administered to Group F patients while Group M patients were given 0.125 % Levobupivacaine + 0.1 mg ml-1 Morphine mixture with 20 min. lock-out time and 5 ml bolus through the PCEA without basal infusion. Before the general anesthesia induction, sensorial, sympathetic and motor blockage levels of the study patients was assessed by pinprick test, hot-cold temperature testing and, Bromage Scale respectively. Peroperative hemodynamic parameters were recorded. Postoperative, Visual Analog Scale (VAS) values, sensorial and motor blockage levels, total drug consumption and adverse effects were recorded and compared.

Results:

Time to arrive T10 of sensory block is compared, it was founded between Group M (17.67±4.14 min.) was longer than Group F (14.9±5.98 min.) (p=0.037). According to Group M; Levels of Group F’s sensory block and sympathetic block, it was high determined in 5th and 15th min. significantly, according to Group M; level of Group F’s sensory block was determined is low. There is no significant differences in levels of sensory block. Group M’s 6th hours post-operative level of sensory block is higher than Group F. (p=0.002). After epidural 30th min. (p = 0.021), before induction of general anesthesia (p=0.014), after induction 0th min. (p=0.011) and the perioperative period (p=0.036) mean arterial pressure levels in Group M compared with Group F is significantly higher. When recumbency VAS score of Group M in 24th hours was higher than Group F (0.63±0.78; 0.45±1.44; p=0.027), there is no differences in 30th min., 2th-6th-1 2th hours. Sitting VAS score of Group M is clearly higher than Group F in 30th. min. (p=0.027). Group F’s the number of epidural bolus which 6hrs (13.18±4.06) and 12. saat (20.82±7.48), is clearly higher than Group M (10.73±4.03; 17.12±7.01) (p=0.017; p=0.042). The incidence of nausea and pruritus in patients with Group M (84.8 %; 63.6 %) is higher than Group F (42.4 %; 9.1 %) (p=0.001).

Conclusion:

Epidural Levobupivacaine-Fentanyl and Levobupivacaine-Morphine anesthesia added to general anesthesia in major lower abdominal surgery and postoperative PCEA both provided similar analgesic and hemodynamic effects. Nevertheless, less adverse effects and more rapid initiation of anesthesia were observed with fentanyl while morphine provides better analgesia in the postoperative early phase.

Keywords: lower abdominal surgery, general anesthesia, epidural anesthesia, patient controlled epidural analgesia, fentanyl, morphine