The Validity and Tolerability of Awake Calibration of the TOF Watch SX Monitor

Neuromuscular blocking agents (NMBAs) are frequently used in anesthesia and quantitative monitoring of neuromuscular block is standard care. Normally the calibration of the neuromuscular monitor is done after anesthesia induction to avoid patient discomfort. Under certain circumstances there is no time for the calibration process. In the so-called rapid sequence induction (RSI) the neuromuscular blocking agent has to be injected immediately after the induction agent. As the neuromuscular monitor cannot be calibrated, precise neuromuscular monitoring is not possible, and this is of particular disadvantage, when high doses of non-depolarizing neuromuscular blockers are injected to fasten the onset of neuromuscular block. The primary objective is to validate the measurements of the TOF Watch SX® monitor calibrated in awake patients by comparing them with the measurements obtained with the TOF Watch SX® monitor calibrated after anesthesia induction (Gold standard). The secondary objective is to evaluate the tolerability of the awake calibration process of the TOF Watch SX® monitor.