A comparison of pretreatment regimens for minimizing the haemodynamic response to blind nasotracheal intubation.

The authors determined the cardiovascular effects of blind nasotracheal intubation in four randomized groups of 25 patients each. After induction of anaesthesia with IV thiopentone 4 mg X kg-1, patients in group A received no pretreatment, while patients in group B received IV lidocaine 1.5 mg X kg-1. Three minutes before induction, patients in group C received 0.25 per cent phenylephrine nasal spray (0.2 mg in each nostril); those in group D received ten per cent lidocaine nasal spray (30 mg in each nostril). After intubation, mean arterial pressures (MAP) were highest in group B (IV lidocaine) patients (p less than 0.05), remaining significantly elevated for 5 min. Conversely, within four minutes after intubation, MAP of group D (ten per cent nasal lidocaine spray) patients were below control (p less than 0.05), and lower than those of any other group (p less than 0.05). MAP of group A and C patients increased after intubation, but not as much as in group B patients (p less than 0.05). There were no adverse effects from the lidocaine nasal spray. Ten per cent lidocaine nasal spray is a safe and effective way to minimize the MAP increases which typically accompany blind nasotracheal intubation in lightly anaesthetized patients.