The effects of midazolam followed by administration of either vecuronium or atracurium on the QT interval in humans.

Prolongation of the QT interval may produce potentially hazardous dysrhythmias. The effects on the QT interval of midazolam followed by administration of either vecuronium or atracurium have been investigated. Thirty patients, ASA I or II, without cardiovascular problems, electrolyte abnormalities or receiving any medication were studied. All patients were premedicated with midazolam 0.08 mg kg-1 i.m. 30-60 min before surgery. Anaesthesia was induced with midazolam 0.4 mg kg-1. ECG recordings as well as heart rate and arterial pressure measurements were obtained before induction of anaesthesia and 1, 3 and 5 min after midazolam administration. Further recordings were obtained at 1, 3 and 5 min after either vecuronium 0.1 mg kg-1 (15 patients) or atracurium 0.5 mg kg-1 (15 patients). Further recordings were obtained immediately after tracheal intubation and at 1, 3 and 5 min later. Midazolam followed by administration of either vecuronium or atracurium did not produce any significant change in QTc interval (QT interval corrected for heart rate). Statistically significant prolongation of QTc was observed in both groups after intubation, although the mean QTc values did not exceed the upper limits of normal. Heart rate and arterial pressure were also increased significantly in both groups after intubation.

RCT Entities:   Population Interventions Outcomes