Rocuronium 0.3 or 0.9 mg/kg comparing onset time, duration of action, and intubating conditions in patients 80 years and older: A randomized study.

BACKGROUND: Limited data exist about the optimal dose of rocuronium for intubation in elderly patients. We hypothesized that rocuronium 0.9 mg/kg would lead to a shorter onset time than 0.3 mg/kg in patients above 80 years. METHODS: Thirty-four patients were randomized to either rocuronium 0.3 or 0.9 mg/kg. The primary outcome was onset time defined as time to train-of-four (TOF) count of 0. Other outcomes included duration of action (time to TOF ratio >0.9), proportion of excellent intubating conditions using the Fuchs-Buder scale and tracheal intubating conditions using the Intubating Difficulty Scale (IDS). RESULTS: Rocuronium 0.9 mg/kg resulted in shorter onset time compared to rocuronium 0.3 mg/kg; 108 s (SD 40) vs. 228 s (SD 140) (difference: 119 s [95% CI: 41-196], p = .005), respectively. However, in 66% of the patients receiving rocuronium 0.3 mg/kg a TOF count of 0 was not obtained. Duration of action was longer after rocuronium 0.9 mg/kg: 118 min (SD 43) vs. 46 min (SD 13) (difference: 72 min [95% CI: 49-95] p < .0001), and a greater proportion of excellent intubating conditions (Fuchs-Buder) was obtained; 11/16 (69%) vs 4/18 (22%) (p = .006). No difference was found regarding IDS score. CONCLUSION: Rocuronium 0.9 mg/kg resulted in a shorter onset time compared to rocuronium 0.3 mg/kg in patients above 80 years of age. In 66% of the patients receiving rocuronium 0.3 mg/kg a TOF count of 0 was not obtained.

A blinded randomized study comparing intubating conditions after either rocuronium 0.6 mg·kg-1 or remifentanil 2 µg·kg-1 in elderly patients.

BACKGROUND: To facilitate tracheal intubation, either a neuromuscular blocking agent or a bolus dose of remifentanil can be administered. We hypothesized that rocuronium 0.6 mg·kg-1 provided a larger proportion of excellent intubating conditions compared to remifentanil 2 µg·kg-1 in patients above 80 years. METHODS: A total of 78 patients were randomized to either rocuronium 0.6 mg·kg-1 or remifentanil 2 µg·kg-1 . General anaesthesia was initiated with fentanyl and propofol. Two minutes after the administration of either rocuronium or remifentanil, tracheal intubating conditions were evaluated using the Fuchs-Buder scale by a blinded investigator, and our primary outcome was the proportion of patients presenting intubating conditions deemed as excellent. Further outcomes included the Intubating Difficulty Scale (IDS), hoarseness or sore throat 24 h postoperatively, and intervention against hypotension. RESULTS: No difference in the occurrence of excellent intubating conditions was found comparing the rocuronium group with the remifentanil group; 10 (28%) versus 15 (39%) (p = .29), respectively, relative risk = 0.72. Interventions against hypotension were used in 24 (67%) versus 28 (74%) (p = .51), respectively. Hoarseness and sore throat 24 h postoperatively were found in 37% versus 35% p = .86, and 14% versus 5% p = .20, respectively. The IDS score was 2 versus 2 p = .48. CONCLUSION: No difference in intubating conditions was found 2 min after the administration of either rocuronium 0.6 mg·kg-1 or remifentanil 2 µg·kg-1 in patients aged above 80 years. Intubation conditions were less than optimal in a large proportion of this patient population. CLINICAL TRIALS REGISTRATION: NCT04287426.