Background:Intraoperative depth of anesthesia may affect postoperative pain relief. This prospective, randomized, and observer-blinded study assessed the effect of intraoperative depth of anesthesia on the postoperative pain and analgesic requirements in patients undergoing laparoscopic cholecystectomy.Materials and Methods:A total of 80 patients were randomly divided into two groups of 40 each. A standard technique for anesthesia was followed in all patients. Depth of anesthesia was monitored by bispectral index (BIS) and adjusted with 0.5 to 1.5% isoflurane in group S by addition of propofol in group B, if required, to maintain a BIS value of 45 to 40. Postoperative analgesia was provided by tramadol 1 mg/kg every 6 hours and rescue analgesia by morphine boluses. Postoperative pain was assessed by Visual analogue scale score at 0, 8, 16, and 24 hours.Results:The demographic characteristics were comparable in both groups. The mean BIS value in Group S was 63.32 ± 11.43 and 45.06 ± 15.31 in Group B, well in the range of 40 to 60, reflecting adequate hypnotic effect for general anesthesia. The mean arterial pressure was low in group B throughout the surgery (P<0.05-0.001). The pain score were lower in group B at 0 and 8 hours postoperatively when compared with group S (P<0.05). The rescue analgesic requirement was less in group B, compared with group S (P<0.05).Conclusion:Maintaining BIS to a value of 45 to 40 throughout the surgery results in better postoperative pain relief and decreased requirement of rescue analgesic without any untoward effect.

The present experimental study was planned to evaluate the effect of intrathecal administration of L-glutamic acid upon antinociception produced by intrathecal morphine in a prospective-controlled manner in conscious freely (P < 0,01). Chez les rats pr6trait$s ~ la naloxone, on remarque la restauration et l'exag~ration de l'antinociception induite par la morphine avec une augmentation du TFL (9,0 -t-0,4 sec; P < 0,0001 L-glutamic acid, a precursor of GABA is an excitatory amino acid (EAA) present in the brain. In addition to its anabclic and catabolic effects it serves as the main mediator of fast excitatory neurotransmission in the mammalian spinal cord ~ and vertebrate neurons. ~ At least three EAA receptor subtypes coexist including those activated by the agonists-N-methyl-D-aspartate (NMDA), (RS)-a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid HBR (AMPA) and kainate. ~,3 Glutamate, an NMDA-reeeptor agonist 4 has been implicated in hypoxic ischaemic brain damage which can be attenuated by morphinan derivatives s and naloxone. 6 CAN J ANAESTH 1995 / 42:6 / pp541-6

Background and Objective:Pain is a complex process influenced by both physiological and psychological factors. In spite of an armamentarium of analgesic drugs and techniques available to combat post-operative pain, appropriate selection, and effective management for relief of post-operative pain still poses unique challenges. The discovery of peripheral opioid receptors has led to growing interest in the use of locally applied opioids (intra-articular, intra-pleural, intra-peritoneal, and perineural) for managing acute pain. As bone graft harvesting is associated with significant post-operative pain and there is a paucity of literature on the use of peripheral opioids at the iliac crest bone harvesting site, the present study was planned to evaluate the analgesic efficacy of local administration of morphine after iliac crest bone graft harvesting.Materials and Methods:A total of 60 patients, 20-50 years of age scheduled to undergo elective surgery for delayed and non-union fracture both bone leg with bone grafting under general anaesthesia (GA) were randomly assigned to one of the four groups of 15 patients each: group 1: 2.5 ml normal saline (NS) +2.5 ml NS infiltrated into the harvest site at 2 sites + 1 ml NS intramuscularly (i/m); Group 2: 2.5 ml NS + 2.5 ml NS infiltrated into the harvest site at 2 sites + 5 mg morphine in 1 ml i/m.; Group 3: 2.5 mg (2.5 ml) morphine + 2.5 mg (2.5 ml) morphine infiltrated into the harvest site at 2 sites + 1 ml NS i/m; Group 4: 0.5 mg naloxone (2.5 ml) +5 mg (2.5 ml) morphine infiltrated into the harvest site at 2 sites + 1 ml NS i/m. Pain from the bone graft site and operative site was assessed for 24 h post-operatively.Results:The patients who had received morphine infiltration (Group 3) had significantly less pain scores at the graft site at 4, 6, and 10 post-operative hours. They also had significantly less morphine consumption and overall better pain relief as compared to the other groups.Conclusions:Morphine administered peripherally provided better analgesia as compared to that given systemically and this effect was noticeable after 4 h post-operatively.