What dose of rocuronium do you use for your rapid sequence intubations? How long do you wait for it to take effect?
These are common questions uttered in anaesthetic and emergency departments as well as intensive care. In 2000 a study suggested that 1.8 – 2.3 mg/kg rocuronium may be required to achieve ‘excellent’ intubating conditions at 60 seconds in the vast majority of patients. The question of whether these larger doses might be better has not been further investigated.
The primary aim of this study is to clarify, with a semi-physiological Kinetic-Pharmacodynamic (KPD) model, the relationship between dose of rocuronium for intubation, cardiac output (CO), and onset of neuromuscular blockade. The model might then suggest dosing and expected onset.
Observational data will be collected from 30 adults undergoing general anaesthesia with muscle paralysis. Rocuronium onset time will be defined as 95 per cent twitch depression of neuromuscular monitoring (NMT) electromyography (EMG) at adductor digiti minimi. Cardiac output measurements will be taken from pulse contour analysis of arterial invasive pressure waveforms. Doses of rocuronium will range between 1.2 mg/kg and 2.0 mg/kg.
Dr Clare Hayes-Bradley, Blacktown Hospital, NSW; Aeromedical Operations, NSW Ambulance.
The project was awarded A$9,428 funding through the ANZCA research grants program for 2025.