Three minutes after administering a standard intubating dose of rocuronium (0.6 mg/kg) to a patient with cirrhosis, you discover the vocal cords are closed during laryngoscopy and the patient is moving. An alteration in which of the following MOST likely explains this finding?
  • □ (A) Hepatic clearance
  • □ (B) The neuromuscular junction
  • □ (C) Volume of distribution

After administration of a standard intubating dose of a nondepolarizing neuromuscular blocking drug (NMBD) in a patient with cirrhosis, there is an apparent resistance to the action of the drug with a delayed onset of action. This is because patients with cirrhosis have an increased volume of distribution that dilutes the drug after administration. Consequently, to achieve ideal intubating conditions, one must either increase the initial dose or wait longer prior to intubation.

For nondepolarizing NMBDs that undergo hepatic metabolism (e.g., rocuronium), the duration of action is often prolonged in the cirrhotic patient due to the altered hepatic clearance. However, hepatic clearance does not affect the onset time.

While alterations in the neuromuscular junction may affect the onset time of rocuronium, this is not the most likely explanation in this cirrhotic patient.