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 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.