Evaluation of the optimal preemptive dose of gabapentin for postoperative pain relief after lumbar diskectomy: a randomized, double-blind, placebo-controlled study.

We evaluated the optimal preemptive dose of gabapentin for postoperative pain relief after single-level lumbar diskectomy and its effect on fentanyl consumption during the initial 24 hours in a randomized, double-blinded, placebo-controlled study in 100 patients with American Society of Anesthesiologists physical status I and II. Patients were divided into five groups to receive placebo or gabapentin 300, 600, 900, or 1200 mg 2 hours before surgery. After surgery, patients were transferred to the postanesthesia care unit (PACU). A blinded anesthesiologist recorded the pain scores at time points of 6, 12, 18, and 24 hours in the PACU on a Visual Analog Scale (VAS; 0-10 cm) at rest. Patients received patient-controlled analgesia (fentanyl 1.0 mug/kg on each demand with lockout interval of 10 minutes); total fentanyl consumption during initial 24 hours was recorded. Data were entered into the statistical software package SPSS 9.0 for analysis (one-way analysis of variance and Student-Newman-Keuls test). Patients who received gabapentin 300 mg had significantly lower VAS score at all time points. They consumed less fentanyl (patients who received placebo processed 1217.5 +/- 182.0 versus 987.5 +/- 129.6 mug; P < 0.05). Patients who received gabapentin 600, 900, and 1200 mg had lower VAS scores at all time points than patients who received gabapentin 300 mg (P < 0.05). Increasing the dose of gabapentin from 600 to 1200 mg did not decrease the VAS score, nor did the increasing dose of gabapentin significantly decrease fentanyl consumption (702.5, 635, and 626.5 microg). Thus, gabapentin 600 mg is the optimal dose for postoperative pain relief following lumbar diskectomy.

Intravenous lidocaine 0.5 mg.kg-1 effectively suppresses fentanyl-induced cough.

PURPOSE: To evaluate the minimal dose of lidocaine required for suppression of fentanyl-induced cough. METHODS: 320 ASA I and II patients, non-smokers of both sexes scheduled for elective surgery between the ages of 18 to 60 yr were randomly allocated into four equal groups. The patients were assigned to receive lidocaine 0.5 mg.kg(-1) (Group I), 1.0 mg.kg(-1)(Group II), 1.5 mg.kg(-1) (Group III) or placebo (Group IV) over five seconds, one minute prior to the administration of fentanyl 3 microg.kg(-1) in a randomized and double-blind fashion. Any episode of cough was classified as coughing and graded as mild (1-2) moderate (3-4) or severe (5 or more). The data were analyzed by test of proportion. RESULTS: Eleven, 12, 11 and 28 patients (13.75%, 15%, 13.75% and 35%) had cough in Groups I, II, III and IV respectively (P < 0.05 Groups I, II, III vs IV). There was no significant difference in the incidence and severity of cough among the lidocaine pretreated groups (P > 0.05). CONCLUSION: The results of our study suggest that iv lidocaine 0.5 mg.kg(-1) is the minimal dose required to suppress fentanyl-induced cough when administered one minute prior to fentanyl. Any further increase in the lidocaine dose does not reduce the incidence or severity of fentanyl-induced cough.

Effect of preoperative dexamethasone on edema of oral and extra-oral structures following trans-oral decompression and posterior fusion.

We investigated the anti-edema effect of intravenous dexamethasone in a randomized, double-blinded, placebo-controlled study in 40 ASA physical status I and II patients scheduled for trans-oral decompression and posterior fusion. Patients were divided into two groups to receive either placebo or 10 mg dexamethasone one hour prior to induction of anesthesia. After anesthesia induction, oral structures were graded as swelling grade 0 at direct laryngoscopy. Duration of trans-oral surgery, duration of posterior fusion, and total duration of surgery were recorded. After completion of surgery, direct laryngoscopy was repeated, and swelling was graded from 1 to 4. Patients who had a swelling grade of 1 or 2 were extubated while grades of 3 and 4 were transferred to a neurosurgical intensive care unit, and re-assessments were performed 12 hours apart. Patients with swelling grades of 1 and 2 were extubated on each assessment. On statistical analysis of the results, the study found that in comparison to placebo, patients in the dexamethasone group were extubated earlier (P < 0.006, Chi Square for trend). Total duration of surgery and duration of posterior fusion were significantly greater (P < 0.05) in patients who had swelling grade >2 than in patients who had swelling grade < or =2 at completion of surgery (192.50 +/- 16.26, 356.07 +/- 17.06 minutes versus. 158.27 +/- 9.07, 311.41 +/- 14.06 minutes).