Zafer Pamukçu

Analgesic Effects of Gabapentin after Spinal Surgery

BackgroundA combination of opioid and nonopioid analgesic drugs may improve the quality of postoperative analgesia as well as reduce opioid requirements and their associated side effects. Studies have shown synergism between gabapentin and morphine in animal and human experiments and in the treatment of incisional pain. Therefore, the authors investigated, in a randomized, placebo-controlled, double-blind study, the effects of gabapentin on acute postoperative pain and morphine consumption in patients undergoing spinal surgery. MethodsAfter standard premedication, 25 patients in the control group received oral placebo, and 25 patients in the gabapentin group received 1,200 mg of gabapentin, 1 h before surgery in a randomized fashion. Anesthesia was induced with propofol and cisatracurium and was maintained with sevoflurane and remifentanil. The total intraoperative remifentanil consumption by each patient was noted. All patients postoperatively received patient-controlled analgesia with morphine (1 mg/ml) with an incremental dose of 2 mg, a lockout interval of 10 min, and a 4-h limit of 40 mg. The incremental dose was increased to 3 mg, and the 4-h limit to 50 mg, if analgesia was inadequate after 1 h. Patients were questioned for the first 1 h in the PACU and were later evaluated in the ward at 1, 2, 4, 6, 12, and 24 h. Pain scores, heart rate, oxygen saturation measured by pulse oximetry, mean blood pressure, respiratory rate, sedation, morphine use, and total dose of morphine were recorded. ResultsOverall, pain scores at 1, 2, and 4 h were significantly lower in the gabapentin group when compared with the placebo group. Total morphine consumption in the gabapentin group was 16.3 ± 8.9 mg (mean ± SD) versus 42.8 ± 10.9 mg in the placebo patients. The incidence of vomiting and urinary retention was significantly (P < 0.05) higher in the placebo group, but there was no difference in incidence of other adverse effects between the groups. ConclusionsPreoperative oral gabapentin decreased pain scores in the early postoperative period and postoperative morphine consumption in spinal surgery patients while decreasing some morphine-associated side effects.

Gabapentin: An Alternative to the Cyclooxygenase-2 Inhibitors for Perioperative Pain Management

The cyclooxygenase-2 inhibitor, rofecoxib, was a popular analgesic adjuvant for improving perioperative pain management. We designed this placebo-controlled study to test the hypothesis that gabapentin could produce similar reductions in postoperative pain and opioid analgesic usage, thereby improving the recovery process. One hundred patients undergoing abdominal hysterectomy procedures were randomly assigned to one of four treatment groups: 1) control group received placebo capsules and pills before and for 2 days after surgery, 2) rofecoxib group received 50 mg/d PO and placebo capsules before and after surgery and, 3) gabapentin group received 1.2 g/d PO and placebo pills before and after surgery, and 4) combination group received rofecoxib 50 mg/d and gabapentin 1.2 g/d PO before and after surgery. The anesthetic technique was standardized and the postoperative assessments included verbal rating scales for pain and sedation, IV morphine usage, quality of recovery assessment, recovery of bowel function, resumption of normal activities, and patient satisfaction with their pain management. Postoperative pain scores were significantly reduced in all three analgesic treatment groups (versus control group). Compared with the control group, patient-controlled analgesia morphine usage was also significantly reduced in the 3 analgesic treatment groups at 1, 8, 24, and 30 h after surgery. Total PCA morphine usage was decreased by 43%, 24%, and 50% in groups 2, 3, and 4, respectively, compared with group 1. Oral analgesic consumption was also smaller in groups 2 and 4 when compared with the control group. The opioid-sparing effects of rofecoxib and gabapentin lead to a faster recovery of bowel function. Discharge eligibility scores in groups 2 and 4 were improved at 24 h when compared with group 1, and patient satisfaction with postoperative pain management was significantly higher at 24 h in all 3 analgesic treatment groups. At the 72 h follow-up, all of the patients in group 4 were completely satisfied with their pain management compared with only 32%, 64%, and 72% in groups 1, 2, and 3, respectively. Gabapentin (1.2 g/d PO) appears to be an acceptable alternative to rofecoxib (50 mg/d PO) for short-term use as an adjuvant to opioid analgesics in patients undergoing lower abdominal surgery.

The Prevention of Pain from Injection of Rocuronium by Ondansetron, Lidocaine, Tramadol, and Fentanyl

We compared the efficacy of ondansetron, lidocaine, tramadol, and fentanyl in minimizing pain caused by the injection of rocuronium in 250 patients. After tourniquet application on the forearm, the patients were given saline (3 mL) (Group 1, n = 50), ondansetron (4 mg) (Group 2, n = 50), lidocaine (30 mg) (Group 3, n = 50), tramadol (50 mg) (Group 4, n = 50), or fentanyl (100 &mgr;g) (Group 5, n = 50) diluted into a 3-mL solution. The occlusion was released after 20 s and rocuronium was injected over 10–15 s. The patients were observed and asked immediately if they had pain in the arm, and the response was assessed. Reactions such as discomfort and pain, withdrawal of the hand, and so on after the administration of rocuronium were recorded as side effects for 24 h. Ten patients in Group 1, 28 patients in Group 2, 37 patients in Group 3, 30 patients in Group 4, and 15 patients in Group 5 reported no pain. Light pain was seen in 11 patients in Group 1, 14 patients in Group 2, 11 patients in Group 3, 12 patients in Group 4, and 20 patients in Group 5. Moderate pain was seen in 15 patients in Group 1, 6 patients in Group 2, 2 patients in Group 3, 8 patients in Group 4, and 10 patients in Group 5. Severe pain was seen in 14 patients in Group 1, 2 patients in Group 2, 0 patients in Group 3, 0 patients in Group 4, and 5 patients in Group 5. Correlation determined with log-linear analysis found in Group 1 pain score 0 (P < 0.001), Group 1 pain score 1 (P < 0.001), and Group 3 pain score 0 (P < 0.001). We conclude that ondansetron, lidocaine, tramadol, and fentanyl decrease the level of rocuronium injection pain. Among these drugs, lidocaine is the most effective, whereas fentanyl is the least effective.

The analgesic effects of gabapentin in monitored anesthesia care for ear-nose-throat surgery

We investigated the efficacy and safety of gabapentin in rhinoplasty or endoscopic sinus surgery patients. Patients received either oral placebo or gabapentin 1200 mg 1 h before surgery. After standard premedication, 25 patients in each group received propofol, fentanyl, and local anesthesia at the operative site. Sedation was maintained by a continuous infusion of propofol adjusted according to the Ramsay scale. Sedation and pain scores were obtained at 5, 15, 30, 45, and 60 min during surgery and 30 min and 2, 4, 6, 8, 12, 16, 20, and 24 h after the procedure. Diclofenac 75 mg IM was administered as a rescue analgesic. Postoperative pain scores and intraoperative pain scores at 45 and 60 min were significantly lower in the gabapentin group. Fentanyl (122 ± 40 μg versus 148 ± 42 μg; P < 0.05) and diclofenac (33 ± 53 mg versus 111 ± 92 mg; P < 0.001) consumption was smaller and the time to first analgesic request (18 ± 9 h versus 9 ± 7 h; P < 0.001) was longer in the gabapentin group. A more frequent incidence of dizziness was found in the gabapentin (versus placebo) group (24% versus 4%, respectively). We conclude that gabapentin provided a significant analgesic benefit for intraoperative and postoperative pain relief in patients undergoing ambulatory rhinoplasty or endoscopic sinus surgery; however, dizziness may be a handicap for ambulatory use.

The use of magnesium sulfate to prevent pain on injection of propofol

IMPLICATIONS Magnesium sulfate, 2.48 mmol, injected 20 s before the administration of propofol significantly reduced the incidence of pain caused by a propofol injection and may be useful in minimizing this common side effect.

Intravenous regional anesthesia using lidocaine and magnesium.

We conducted this study to evaluate the effects of magnesium, when added to lidocaine for IV regional anesthesia (IVRA), on tourniquet pain. Thirty patients undergoing elective hand surgery during IVRA were randomly assigned to two groups. IVRA was achieved with 10 mL of saline plus 3 mg/kg lidocaine 0.5% diluted with saline to a total of 40 mL in group C or with 10 mL of 15% magnesium sulfate (12.4 mmol) plus 3 mg/kg lidocaine 0.5% diluted with saline to a total of 40 mL in group M. Injection pain, sensory and motor block onset and recovery time, tourniquet pain, and anesthesia quality were noted. Patients were instructed to receive 75 mg of IM diclofenac when the visual analog scale (VAS) score was >4, and analgesic requirements were recorded. Sensory and motor block onset times were shorter and recovery times were prolonged in group M (P < 0.05). VAS scores of tourniquet pain were lower in group M at 15, 20, 30, 40, and 50 min (P < 0.001). Anesthesia quality, as determined by the anesthesiologist and surgeon, was better in group M (P < 0.05). Time to the first postoperative analgesic request in group C was 95 ± 29 min and in group M was 155 ± 38 min (P < 0.05). Postoperative VAS scores were higher for the first postoperative 6 h in group C (P < 0.05). Diclofenac consumption was significantly less in group M (50 ± 35 mg) when compared with group C (130 + 55 mg) (P < 0.05). We conclude that magnesium as an adjunct to lidocaine improves the quality of anesthesia and analgesia in IVRA.

Intravenous regional anesthesia using prilocaine and neostigmine.

Neostigmine has been added to local anesthetics for central and peripheral nerve blocks resulting in prolonged, increased anesthesia and improved analgesia. We conducted this study to evaluate the effects of neostigmine when added to prilocaine for IV regional anesthesia (IVRA). Thirty patients undergoing hand surgery were randomly assigned to two groups to receive IVRA. The control group received 1 mL of saline plus 3 mg/kg of prilocaine diluted with saline to a total dose of 40 mL; the study group received 0.5 mg of neostigmine plus 3 mg/kg of prilocaine diluted with saline to a total dose of 40 mL. Sensory and motor block onset and recovery, anesthesia quality determined by an anesthesiologist, anesthesia quality determined by a surgeon, and dryness of the operative field were noted. Heart rate, mean arterial blood pressure, and oxygen saturation values were noted at 1, 5, 10, 20, and 40 min before surgery and after tourniquet release. Time to first analgesic requirement was also noted. Shortened sensory and motor block onset times, prolonged sensory and motor block recovery times, improved quality of anesthesia, and prolonged time to first analgesic requirement were found in the neostigmine group. We conclude that neostigmine as an adjunct to prilocaine improves quality of anesthesia and is beneficial in IVRA.

Comparison of the laryngeal mask (LMA ™ ) and laryngeal tube (LT ® ) with the new perilaryngeal airway (CobraPLA ® ) in short surgical procedures

Background and objective: We compared the laryngeal mask airway (LMA™) and the laryngeal tube (LT®) with the newly introduced perilaryngeal airway (CobraPLA®, PLA) with regard to haemodynamic responses induced by airway insertion, clinical performance and occurrence of postoperative sore throat after short surgical procedures. Methods: After premedication, 90 ASA I–II patients awaiting short surgical procedures were randomized to receive, LMA, LT or PLA. Anaesthesia was induced with intravenous propofol (2.5 mg kg−1) and mivacurium (0.2 mg kg−1). Number of attempts, time of insertion of the device, any other unwanted effect, mean aterial pressure, heart rate, oxygen saturation and end‐tidal carbon dioxide were recorded. At the end of surgery, the cuff of the device was immediately deflated and the airway device was removed. The device was examined and noted for the presence of visible blood. Patients were asked to rate their throat soreness, dysphonia and dysphagia 1 and 24 h postoperatively. Results: There were no differences in haemodynamic variables. Insertion times for the devices were similar (LMA: 20 ± 11 s, LT: 19 ± 14 s and PLA: 21 ± 12 s.) The success rates at first insertion were lower in the (LMA group (57%) when compared with the PLA (97%, P < 0.05). The number and type of airway interventions for achieving an effective airway were similar. When the airways were removed 50% of the PLA devices had positive blood traces, while only 17% of the LMA and LT devices had positive blood traces (P < 0.01). Fifty percent of the patients suffered from a sore throat in the PLA group, which was significantly higher than in the LMA and LT groups (P < 0.05). Conclusion: We conclude that haemodynamic, ventilation and oxygenation variables throughout the surgery were similar with, LMA, LT and PLA, but LT and PLA were easier to insert; LMA and LT caused less mucosal trauma.

Analgesic effects of rofecoxib in ear-nose-throat surgery.

In this study we evaluated the analgesic efficacy and the opioid-sparing effect of rofecoxib in ear-nose-throat surgery patients. Patients undergoing nasal septal or sinus surgery were randomized to receive either oral placebo or rofecoxib 50 mg 1 h before surgery. All patients received propofol 0.8 mg/kg, fentanyl 1 &mgr;g/kg, and local anesthesia at the operative site. Sedation was maintained by a continuous infusion of propofol adjusted to maintain sedation at a 2–3 level on the Ramsey scale. Additional fentanyl 0.5–1 &mgr;g/kg was administered at the patient’s request or if the verbal rating scale score was >4. Patient sedation and pain scores were obtained at 5, 15, 30 45, and 60 min during surgery and 30 min and 2, 4, 6, 12, and 24 h after completion of the procedure. During the postoperative period, diclofenac 75 mg IM was administered for analgesia at the patient’s request or if the visual analog scale (VAS) rating for pain was more than 4. VAS pain scores, intraoperative fentanyl, and postoperative diclofenac requirements were significantly smaller in the rofecoxib group compared with the placebo group (P < 0.001). The times to first analgesic request were also significantly less in the rofecoxib group. We conclude that the preoperative administration of oral rofecoxib provided a significant analgesic benefit and decreased the need for opioids in patients undergoing nasal septal and nasal sinus surgery.

PREMEDICATION WITH GABAPENTIN: THE EFFECT ON TOURNIQUET PAIN AND QUALITY OF INTRAVENOUS REGIONAL ANESTHESIA

BACKGROUND:Gabapentin, an oral non-opioid analgesic, has been used to decrease pain after a variety of surgical procedures. We hypothesized that premedication with gabapentin would minimize tourniquet-related pain in patients receiving IV regional anesthesia (IVRA). METHODS:Patients undergoing elective hand surgery with IVRA were randomly assigned to one of two study groups using a double-blind study design. The control group (n = 20) received placebo capsules 1 h before the surgery, and the gabapentin group (n = 20) received gabapentin 1.2 g p.o. before the operation. IVRA was achieved in all patients with lidocaine, 3 mg/kg, diluted with saline to a total volume of 40 mL. Fentanyl, 0.5 &mgr;g/kg IV, was administered as a rescue analgesic during surgery. Sensory and motor block onset and recovery times, tourniquet pain, and quality of anesthesia were assessed at specific time intervals during the perioperative period. Visual analog scale pain scores (0–10) were recorded during the 24 h follow-up period, and patients received diclofenac, 75 mg IM, if their pain score was >4. RESULTS:The onset of the sensory and motor block did not differ between the two study groups. However, tourniquet pain scores at 30, 40, 50, and 60 min after cuff inflation were lower in the gabapentin group (P < 0.05). The time to intraoperative analgesic rescue was prolonged in the gabapentin group (35 ± 10 min vs 21 ± 13 min, P < 0.05), and less supplemental fentanyl was required (35 ± 47 &mgr;g vs 83 ± 73 &mgr;g, P < 0.05). The quality of anesthesia, as independently assessed by the anesthesiologist and the surgeon, was significantly better in the gabapentin (versus control) group. In the gabapentin group, the time to requesting a rescue analgesic after surgery was prolonged (135 ± 25 min vs 85 ± 19 min, P < 0.05), and postoperative pain scores at 60 min (3.8 ± 0.9 vs 2.2 ± 0.5) and 120 min (3.2 ± 1.4 vs 1.8 ± 0.8), as well as diclofenac consumption (30 ± 38 mg vs 60 ± 63 mg), were reduced after surgery. CONCLUSIONS:Premedication with oral gabapentin (1.2 g) decreased tourniquet-related pain and improved the quality of anesthesia during hand surgery under IVRA. Gabapentin also reduced pain scores in the early postoperative period.