Gabapentin versus naproxen in the management of failed back surgery syndrome; a randomized controlled trial.

Gabapentin is an analogue of the gamma amino butyric acid (GABA), which regulates the conductance of calcium channels. In this study, we compared the efficacy of gabapentin the one of naproxen in the treatment of failed laminectomy syndrome. In this controlled trial, patients who had had elective lumbar discectomy or spinal fusion surgery more than one year ago, and complaining about leg and back pain in spite of different medical therapy were randomly assigned to receive naproxen (control group) or gabapentin. Gabapentin was started at a daily dose of 300 mg. This dose was increased by 300 mg at the end of each week up to a maximum dose of 1800 mg. Naproxen, which was administered at an initial daily dose of 250 mg, was increased similarly to the maximum 1500 mg. Patients were then followed up for the next 6 consecutive months. Back and leg pains were compared between the two groups at 9 consecutive time points, namely 0, 2, 4, 6, 8, 12, 16, 20 and 32 weeks after starting the treatment. The Visual Analog Scale (VAS) score of the back pain was significantly reduced when a 600 mg daily dose of gabapentin was reached (P < 0.001). At a dose of 1800 mg, the decrease in back pain amounted 20.5%. Naproxen-treated patients did not show significant improvement in back pain. Leg pain as similarly assessed by a VAS significantly decreased when a 1200 mg dose of gabapentin was attained (P < 0.008). At 1800 mg, the reduction in VAS was 39.2%. Naproxen-treated patients had a 7.7% pain reduction at 6th week, when using the maximum daily dose of 1500 mg (P < 0.04), but the pain increased thereafter. We conclude that Gabapentin, at a maximum daily dose of 1800 mg, is significantly more efficient than naproxen at treating persistent pain after spinal surgeries.

Combination of remifentanil with isoflurane or propofol: effect on the surgical stress response.

BACKGROUND: Hormonal and metabolic changes following surgery are markers of the stress response to surgery. We compared hemodynamic parameters and stress response markers (glucose, cortisol, and C-reactive protein) in two groups of patients receiving either propofol or isoflurane combined with remifentanil for maintenance of anesthesia. METHODS: We randomly assigned 100 women (ASA I-II) scheduled for diagnostic gynecologic laparoscopy to receive either isoflurane (0.8% end-tidal) or propofol (100 mg/kg/min) in addition to remifentanil (0.25 mg/ kg/min). Heart rate and mean arterial pressure were recorded after induction, 30 seconds after intubation, at four time points after incision, and 60 min after surgery. Serum C-reactive protein, cortisol and glucose concentrations were measured before induction, one hour after incision, and one hour after surgery. RESULTS: After induction, heart rate decreased significantly from baseline in both groups, and remained below baseline until the end of surgery. Mean arterial pressure also decreased significantly in both groups. C-reactive protein levels were not significantly different between groups. In the propofol group, cortisol decreased significantly one hour after incision, but increased in the isoflurane group. Glucose increased significantly in both groups, but was significantly lower in the propofol group one hour after the incision and one hour after surgery. CONCLUSION: An anesthetic regimen combining propofol and remifentanil attenuates two indicators of the stress response more efficiently than a isoflurane - remifentanil combination.

The effect of ketamine and fentanyl in reducing the pain of diazepam injection.

Diazepam is an effective drug that is used widely in modern anesthesia. Venous irritation is one of its major side effects attributed to its acqueous insolubility and requisite solvents. There is some evidence that ketamine may acts as a local anesthetic drug, because of its effect on N-methyl-D-aspartate receptors. Fentanyl also may reduce the pain of diazepam injection by blocking the opiate receptors in vessels walls. To determine the effectiveness of ketamine and fentanyl in reducing the pain of diazepam injection, 150 patients (ASA I, II) were randomly assigned to one of three Groups and before intravenous diazepam injection. 2 ml normal saline, 2 ml fentanyl or 10 mg ketamine were administered for Groups 1, 2, 3 respectively. The pain of diazepam injection was then evaluated at 30 minutes intervals. Our results showed that ketamine and fentanyl reduce the pain of diazepam dramaticaly (p < 0.001) in comparison with placebo. Ketamine is more effective than fentanyl in reducing such pain (p < 0.001).