rocuronium and Intracranial-Aneurysm

This study assessed the concentration of rocuronium in the cerebrospinal fluid (CSF) of patients undergoing cerebral aneurysm clipping, and investigated whether the mode of administration (single bolus vs continuous infusion) influenced the CSF concentration.. Twenty patients with subarachnoid haemorrhage were randomly allocated to receive a bolus dose (bolus group), or a bolus followed by a continuous infusion of rocuronium (infusion group) (n=10 for each group). Arterial blood and ventricular CSF were sampled 2 h after the rocuronium bolus. Samples were analysed by liquid chromatography electrospray ionization-tandem mass spectrometry.. Rocuronium could be detected in all the CSF samples. The mean (range) CSF concentration was 2.2 (0.9-4.6) ng x ml(-1) in the bolus group and 12.4 (2.4-34.6) ng x ml(-1) in the infusion group; P<0.01.. This study demonstrated that rocuronium, normally not considered to cross the blood-brain barrier, is regularly found in the CSF of patients undergoing cerebral clipping; continuous infusion of the drug led to higher plasma and CSF concentrations than after a single bolus dose.

Topics: Adult; Androstanols; Blood-Brain Barrier; Drug Administration Schedule; Female; Humans; Intracranial Aneurysm; Intraoperative Period; Male; Middle Aged; Neuromuscular Nondepolarizing Agents; Rocuronium

Hypothermia prolongs the time-course of action of non-depolarizing neuromuscular blocking agents. The mechanism, however, is unknown. We studied the influence of hypothermia (by surface cooling, nasopharyngeal temperature < or = 31 degrees C) on the time-course of action and on the pharmacokinetics of rocuronium in humans. Nineteen neurosurgical patients were divided into hypothermic and normothermic groups. Hypothermia (30.4 +/- 0.8 degrees C (mean +/- SD)) increased the duration of action, temperature dependently, and delayed the recovery. Hypothermia reduced the plasma clearance significantly (2.17 +/- 0.62 vs. 4.26 +/- 0.50 mL kg-1 min-1, P = 0.004), did not change the volume of distribution (224 +/- 64 vs. 232 +/- 60 mL kg-1 min-1, P = 1.0), and prolonged the mean residence time (108 +/- 39 vs. 56 +/- 19 mL kg-1 min-1, P = 0.01). We conclude that hypothermia prolongs the duration of action of rocuronium and delays spontaneous recovery and that altered pharmacokinetics, such as a decreased clearance, play an important role in this.

Topics: Androstanols; Anesthesia; Female; Humans; Hypothermia, Induced; Intracranial Aneurysm; Male; Middle Aged; Muscle Contraction; Neuromuscular Nondepolarizing Agents; Rocuronium

Administration of rocuronium to facilitate intubation has traditionally been regarded as acceptable for intraoperative motor evoked potential (MEP) monitoring because of sufficiently rapid spontaneous neuromuscular blockade recovery. We hypothesized that residual neuromuscular blockade, in an amount that could hinder optimal neuromonitoring in patients undergoing intracranial aneurysm clipping, was still present at dural opening. We sought to identify how often this was occurring and to identify factors which may contribute to prolonged blockade. Records of 97 patients were retrospectively analyzed. Rocuronium was administered to facilitate intubation with no additional neuromuscular blockade given. Prolonged spontaneous recovery time to a train-of-four (TOF) ratio of 0.75 after rocuronium administration was defined as 120 min, which was approximately when dural opening and the setting of baseline MEPs were occurring. Logistic regression analysis was used to identify factors related to prolonged spontaneous recovery time. Prolonged spontaneous recovery time to a TOF ratio of 0.75 was observed in 44.3% of patients. Multivariable analysis showed that only the dosage of rocuronium based on ideal body weight had a positive correlation with prolonged spontaneous recovery time (P = 0.01). There was no significant association between dosage of rocuronium based on total body weight, age, sex, or body temperature and prolonged recovery time. This study demonstrates that the duration of relaxation for MEP monitoring purposes is well-beyond the routinely recognized clinical duration of rocuronium. Residual neuromuscular blockade could result in lower amplitude MEP signals and/or lead to higher required MEP stimulus intensities which can both compromise monitoring sensitivity.

Topics: Androstanols; Evoked Potentials, Motor; Humans; Intracranial Aneurysm; Intubation, Intratracheal; Neuromuscular Blockade; Neuromuscular Nondepolarizing Agents; Retrospective Studies; Rocuronium