Misra, S., Parthasarathi, G., & Vilanilam, G.C. (2013). The effect of gabapentin premedication on postoperative nausea, vomiting, and pain in patients on preoperative dexamethasone undergoing craniotomy for intracranial tumors. Journal of Neurosurgical Anesthesiology, 25, 386–391.

To determine if prophylactically administered 600 mg oral gabapentin reduces postoperative nausea or emesis and decreases postcraniotomy pain

Patients to undergo elective craniotomy were randomized to receive either placebo (a vitamin b-complex capsule) or 600 mg oral gabapentin two hours before induction of anesthesia. All received standard antiepileptic prophylaxis with 100 mg phenytoin every eight hours and 4 mg IV dexamethasone every eight hours for 48 hours prior to surgery. Patients were given 1 gm IV paracetamol every six hours for postoperative pain. Rescue analgesia was provided with 1 mcg/kg IV fentanyl for a pain score of 3. Rescue antiemetic was provided with 4 mg IV ondansetron if the patient had any emetic episode or 10 minutes or longer of nausea. All received the same anesthesia. Symptoms were assessed hourly for the first six hours postoperatively and then every two hours for the next 18 hours.

• N = 73  
• MEAN AGE = 44 years
• MALES: 68.5%, FEMALES: 31.5%
• KEY DISEASE CHARACTERISTICS: All were undergoing craniotomy
• OTHER KEY SAMPLE CHARACTERISTICS: Duration of anesthesia averaged slightly more than 400 minutes and was not different between study groups.

• SITE: Single site   
• SETTING TYPE: Inpatient   
• LOCATION: India

• PHASE OF CARE: Active antitumor treatment

• Placebo-controlled RCT

• Pain verbal rating scale of 0 (no pain) to 3 (moderate to severe, requiring rescue)

Incidence of nausea was 35.1% in the placebo group compared to 11.1% in the gabapentin group (p = .02). No significant difference was seen between groups in incidence of emesis, but there was a trend to lower incidence of emesis with gabapentin. No difference was seen between groups in postoperative pain scores, the number of patients who required rescue analgesia, or postoperative fentanyl consumption.

Prophylactic oral gabapentin prior to surgery reduced postoperative nausea and vomiting in patients undergoing craniotomy. Perioperative gabapentin had no effect on postoperative pain.

• Small sample (less than 100)
• Risk of bias (no blinding)
• Measurement validity/reliability questionable
• The method of pain measurement is questionable, as a 3-point scale.

Preoperative gabapentin may reduce postoperative symptoms of nausea and vomiting in patients undergoing craniotomy who are receiving dexamethasone perioperatively. The optimum dosage of gabapentin has not been determined.