Effect of remifentanil on the auditory evoked response and haemodynamic changes after intubation and surgical incision

Abstract

We have observed the effect of intubation and incision, as measured by the auditory evoked response (AER) and haemodynamic variables, in 12 patients undergoing hernia repair or varicose vein surgery who received remifentanil as part of either an inhaled anaesthetic technique using isoflurane or as part of a total i.v. technique using propofol. Anaesthesia was induced with remifentanil 1 microgram kg-1 and propofol, neuromuscular block was achieved with atracurium 0.6 mg kg-1 before intubation, and anaesthesia was maintained with a continuous infusion of remifentanil in combination with either a continuous infusion of propofol or inhaled isoflurane. The AER and haemodynamic variables were measured before and after intubation and incision. The effects of intubation and incision on the AER and haemodynamic variables were not significantly different between the remifentanil-propofol and remifentanil-isoflurane groups. However, the study had a low power for this comparison. When the data for the two anaesthetic combinations were pooled, the only significant effects were increases in diastolic arterial pressure and heart rate immediately after intubation; these were not seen 5 min after intubation. There were no cardiovascular responses to incision. There were no significant changes in the AER after intubation or incision.

Remifentanil and Other Opioids

“…with a regional technique). Clinically, remifentanil titratability translates into a better control over adrenergic stimuli whatever the type of surgery or the patients (Kapila et al 1995;Mouren et al 2001;Schuttler et al 1997;Cartwright et al 1997;Gemma et al 2002;Guy et al 1997;Howie et al 2001;McGregor et al 1998;Sneyd et al 2001;Ahonen et al 2000;Balakrishnan et al 2000;Casati et al 2000;Doyle et al 2001;Fleisher et al 2001;Natalini et al 1999;Twersky et al 2001;Wee et al 1999;Wilhelm et al 2001). For example, intubation is a stronger stimulus than laryngoscopy, which in turn is stronger than skin incision.…”

Evoked potential monitoring in anaesthesia and analgesia

“…Morphine causes similar dose-dependent changes in SEPs to fentanyl [99]. Pethidine causes increases in latency, but may also result in increases in ............................................................................................................................................................................................................................................ .h À1 or 0.6% end-tidal isoflurane obtunded the early cortical effects of intubation and incision [101]. Remifentanil also reduces auditory and somatosensory evoked responses during isoflurane anaesthesia in a dose-dependant manner [102].…”