Non-Feasibility to Estimate the Need for Reversal of Neuromuscular Relaxation from the Applied Rocuronium Dosing Pattern: A Retrospective Analysis of Anaesthesia Records

Objective: Some anaesthetists are convinced that a long interval since the last relaxant dose may be sufficient to recover from anaesthesia without a pharmacological reversal. We intended to demonstrate that the dosing pattern of rocuronium could not predict the necessity of reversal. Methods: In a cohort analysis, we retrospectively analysed 180 anaesthesia records of adult patients who underwent elective surgical interventions in general anaesthesia and tracheal intubation with rocuronium-induced neuromuscular blockade. The extracted records were divided to 3 post hoc groups of 60 each, according to the reversal method employed at the end of anaesthesia: group N with neostigmine, group S with sugammadex and group Z without pharmacological reversal. All cases were terminated after achieving a train of four ratio of 0.9. Dosing patterns of rocuronium were compared by applying a novel pharmacometric calculation method, residual drug activity coefficient (RDAC), which employs both the administered individual drug doses in mg kg-1 and the timing of each drug administration in relation to the time of extubation. The rocuronium dosing pattern was correlated with the employed method of neuromuscular blockade reversal. Results: The dosing for rocuronium in patients without pharmacological reversal was lower than that in both reversal agent groups (n=0.58±0.21, S=0.58±0.17 and Z=0.47±0.17), but there was still a large overlap in the RDAC. Conclusion: The dosage profile of rocuronium alone cannot predict the possibility to refrain from pharmacological reversal