Hee Cheol Jin

Prophylactic effect of dexamethasone in reducing postoperative sore throat

Background This study was performed to compare the effectiveness of prophylactic dexamethasone and postintubation dexamethasone in reducing the incidence and severity of postoperative sore throat (POST). Methods This was a prospective, randomized, double-blind clinical trial. The study population consisted of 70 patients between 20 and 60 years old who were classified as American Society of Anesthesiologists I-II and were scheduled for elective laparoscopic cholecystectomy. The patients were divided randomly into two groups. Patients in the prophylactic and postintubation groups received intravenous injection of 10 mg of dexamethasone 30 min before or after tracheal intubation, respectively. The patients were interviewed 1, 6, and 24 h after the operation. The incidence and severity of POST were recorded. Results The severity scores of POST at 1 and 6 h after the operation were significantly lower in the prophylactic group than in the postintubation group. There were no significant differences in the incidence of POST during the 24 h after the operation between the two groups (22/32 in the prophylactic group vs. 27/34 in the postintubation group, P = 0.403). Conclusions Intravenous injection of 10 mg of dexamethasone was more effective in reducing the severity of POST when administered before tracheal intubation compared with after tracheal intubation.

The Effect of Low-dose Ketamine on Post-caesarean Delivery Analgesia after Spinal Anesthesia

Background Ketamine, an N-methyl-D-aspartate receptor antagonist, might play a role in postoperative analgesia, but its effect on postoperative pain after caesarean section varies with study design. We investigated whether the preemptive administration of low-dose intravenous ketamine decreases postoperative opioid requirement and postoperative pain in parturients receiving intravenous fentanyl with patient-controlled analgesia (PCA) following caesarean section. Methods Spinal anesthesia was performed in 40 parturients scheduled for elective caesarean section. Patients in the ketamine group received a 0.5 mg/kg ketamine bolus intravenously followed by 0.25 mg/kg/h continuous infusion during the operation. The control group received the same volume of normal saline. Immediately after surgery, the patients were connected to a PCA device set to deliver 25-µg fentanyl as an intravenous bolus with a 15-min lockout interval and no continuous dose. Postoperative pain was assessed using the cumulative dose of fentanyl and visual analog scale (VAS) scores at 2, 6, 24, and 48 h postoperatively. Results Significantly less fentanyl was used in the ketamine group 2 h after surgery (P = 0.033), but the difference was not significant at 6, 12, and 24 h postoperatively. No significant differences were observed between the VAS scores of the two groups at 2, 6, 12, and 24 h postoperatively. Conclusions Intraoperative low-dose ketamine did not have a preemptive analgesic effect and was not effective as an adjuvant to decrease opioid requirement or postoperative pain score in parturients receiving intravenous PCA with fentanyl after caesarean section.

The effect of rocuronium on heart rate variability in diabetic patients

BACKGROUND Clinically rocuronium, a muscle relaxant, has no significant inhibitory effect on the autonomic nervous system in the healthy population. However, there has been no study done on rocuronium in diabetic patients. Therefore, we used heart rate variability (HRV) as a biomarker to investigate cardiac autonomic function after rocuronium administration to diabetic patients. METHODS In 21 diabetic adult patients, heart rate (HR), mean arterial blood pressure (BP), low frequency (LF, 0.04-0.15 Hz) power, high frequency (HF, 0.15-0.4 Hz) power, LF/HF ratio, SD1 and SD2 in the Poincare plot before induction of anesthesia, and immediately before and after rocuronium administration were calculated and compared. RESULTS HR, mean BP, LF, LF/HF ratio and SD2 after rocuronium administration did not differ significantly from the measurements taken before rocuronium administration. HF and SD1 decreased significantly after rocuronium administration (P = 0.022, P = 0.019 respectively). Covariates such as age, gender, weight, duration of diabetes mellitus and hypertension did not alter the effect of rocuronium on the autonomic nervous system. CONCLUSIONS Rocuronium produced a significant decrease in parasympathetic activity. Therefore, further study will be needed to determine whether vagal reduction caused by rocuronium could have potential to deteriorate hemodynamics in diabetic patients.