Early intravenous cannulation in children during inhalational induction of anaesthesia

Intravenous cannulation is obtained in almost all patients scheduled for operative intervention under anaesthesia. Ln our practice, inhalational induction precedes cannulation in children in order to avoid pain and discomfort, and cannulation is delayed until the child is adequately anaesthetized in fear of precipitating laryngospasm due to painful stimulus of venepuncture in the light stage of anaesthesia. This study was performed on 150 patients between two to eight years of age to determine if there is a difference in the incidence of untoward incidents, if cannulation is performed when children are lightly anaesthetized (Early, Group E), as compared to when they are deeply anaesthetized (Late, Group L). In patients randomized to early cannulation, the results showed that there was a significantly shorter time from induction to venous cannulation, the halothane concentration was lower at the time of cannulation, there was a greater incidence of movement on cannulation and a greater incidence of changes in heart rate, blood pressure, and respiratory rate. There was no significant differences in the incidence of laryngospasm or in the success rate of intravenous cannulation between the two groups. We conclude that venous cannulation can be safely performed during the light stages of anaesthesia.