Optimal neuromuscular blocking effects of remifentanil during tracheal intubation under general anesthesia.

Objective This study was performed to determine the effect of the remifentanil dose on the onset time of rocuronium with electromyography. Methods This retrospective comparative study included 75 patients undergoing general anesthesia for elective surgery. Patients received lidocaine (40 mg) and propofol (2 mg/kg) followed by rocuronium (0.6 mg/kg) with either saline infusion (Group S), remifentanil at 0.5 µg/kg/minute (Group R 0.5), or remifentanil at 1.0 µg/kg/minute (Group R 1.0). Neuromuscular block was monitored by train-of-four (TOF) electromyography, and the times taken to reach TOF 0 and TOF ratio (TOFR) 25% were recorded. Results The times taken to reach TOF 0 and TOFR 25% were significantly higher in Groups R 0.5 and R 1.0 than in Group S. The time taken to reach TOF 0 was 130.0 ± 6.4 s in Group S, 142.6 ± 6.0 s in Group R 0.5, and 183.0 ± 11.6 s in Group R 1.0. The time taken to reach TOFR 25% was also higher in Groups R 0.5 and R 1.0 than in Group S. Conclusions As the remifentanil dose increases, the intubation time required to reach TOF 0 also increases. Remifentanil has an effect on the onset of rocuronium.

Variation in intraocular pressure caused by repetitive positional changes during laparoscopic colorectal surgery: a prospective, randomized, controlled study comparing propofol and desflurane anesthesia.

Laparoscopic surgery is often prolonged and requires positional changes to facilitate surgical access. Previous studies reported intraocular pressure (IOP) changes in one fixed position. This study investigated the effect of desflurane and propofol anesthesia on IOP during repeated positional changes. A total of 46 patients undergoing laparoscopic colorectal surgery were randomized into desflurane or propofol groups. IOP was measured using a handheld tonometer at seven time points: before induction (baseline), after endotracheal intubation, after pneumoperitoneum, after the first Trendelenburg and right tilt position, after reverse Trendelenburg and right tilt position, after the second Trendelenburg and right tilt position and before endotracheal extubation. Trendelenburg positioning raised IOP in both groups. In the desflurane group, IOP at the first Trendelenburg position was 6.27 and 8.48 mmHg higher than baseline IOP in left and right eye, respectively; IOP at the second Trendelenburg position was 7 and 9.44 mmHg higher than baseline in left and right eye, respectively. In the propofol group, IOP at the first Trendelenburg position was 2.04 and 4.04 mmHg higher than baseline in left and right eyes, respectively. It was 3.04 and 4.87 mmHg higher than baseline in left and right eye, respectively, at the second Trendelenburg position. In the desflurane group, 56.52% patients exhibited high IOP (≥ 25 mmHg) compared with 13.04% in the propofol group at the second Trendelenburg position in the right eyes (P = 0.005). There was a positive correlation between IOP and peak inspiratory pressure (P < 0.001). Propofol anesthesia mitigated wide variations in IOP caused by repetitive positional changes during laparoscopic colorectal surgery.