Haemodynamic responses to laryngoscopy and tracheal intubation in geriatric patients: effects of fentanyl, lidocaine and thiopentone.

The haemodynamic responses to laryngoscopy and intubation after induction of anaesthesia with thiopentone alone or in combination with 1.5 mg.kg-1 lidocaine and/or 1.5 or 3.0 microgram.kg-1 fentanyl were measured in 150 patients over 64 years of age to determine whether lidocaine, fentanyl or both lidocaine and fentanyl attenuated the pressor response. Fentanyl reduced the rises in systolic, diastolic and mean arterial pressures, heart rate, and rate pressure product and lidocaine decreased the rises in arterial blood pressure and rate pressure product (P less than 0.05). Fentanyl decreased the incidence of marked fluctuations in haemodynamic variables, often seen in geriatric patients (P less than 0.05). The haemodynamic effects of lidocaine and fentanyl were independent of each other. Complications occurred in all groups. Lidocaine-treated patients had fewer cardiac dysrhythmias (P less than 0.05) and 34 per cent of them had tinnitus. Fentanyl-treated patients had a higher incidence of hypotension (P less than 0.05). Respiratory depression developed in only one per cent of the fentanyl-treated patients. Both lidocaine and fentanyl are recommended adjuncts to induction of anaesthesia with thiopentone in geriatric patients.