Does the Choice of Administration Sequence of Propofol and Remifentanil Affect the ED50 and ED95 of Rocuronium for Rapid Sequence Induction of Anesthesia?

Rapid sequence induction is a widely used anesthesia technique to achieve a safe airway control. However, the difficult airway may be expected in these patients as in the others. In the difficult airway situation, cholinesterase inhibitors and sugammadex may be used for the reversal. However, sugammadex is not always available due to its cost in every hospital. In addition to this, it is well-known that cholinesterase inhibitors do not work well in case of deep neuromuscular block. In consideration of these informations, the recovery of the neuromuscular block gain an importance in patients undergoing RSI with difficult airway. Therefore, decreasing the dosage of non-depolarizing neuromuscular agent may be helpful in case of the difficult airway situations. With the aim of decreasing the neuromuscular blocker dosage, opioid analgesics especially remifentanil is preferred combined with propofol to decrease the hemodynamic response to laryngoscopy and intubation. A recent study demonstrated that after induction of anesthesia with remifentanil and propofol, ED50 of rocuronium for acceptable intubation conditions was 0.20 mg/kg. In another study, the authors showed that the administration sequence of propofol and remifentanil for target controlled anesthesia affect the onset time of rocuronium due to change in cardiac output. The authors concluded that the prior administration of remifentanil decreased the cardiac output and delayed the onset time of rocuronium.

The investigators hypothesized that prior administration of remifentanil compared to propofol may increase the ED50 and ED95 of rocuronium for acceptable intubation conditions in RSI.