A Comparison of Mono-inhalational and Balanced Anaesthesia in Infants of Lowest Weight Groups

Overview

Objective:
To compare cardiovascular stability and recovery time in anaesthesia with and without opioid; to evaluate the possibilities to achievebetter cardiovascular stability with application of potent, easy-to-titrate analgetic agent.Study design: Retrospective study.Setting: ARO and COS, University Hospital Brno, Children Hospital.Patients: Newborns and infants up to 5,000 g weight with intact carciovascular system who were scheduled for anaesthesia with tracheal intubation(anaesthesia time > 60 min). The study period was between January 1997 and February 1999.Interventions: Inhalational anaesthesia was maintained with isoflurane (68%) or halothane (41%). Mono-inhalational induction with max. 3,5%was followed by maintenance dose of 1–2,5%. Alfentanil was chosen for balanced anaesthesia, due to his favorite pharmacological properties. Alfentanilwas administered after inhalational induction with 3% maximal concentration as a bolus dose of 10–15 mcg/kg prior to skin incision. Supplementarydoses were added to lower inhalational concentration of volatile anaesthetic (0,4–1,2%) in a continuous infusion 0,5–1,5 mcg/kg/min or in a bolusdoses of 10–20 mcg/kg. We evaluated heart rate variability, recovery time and mean arterial pressure in important phases of a surgical procedure.For statistical evaluation, paired t-test was used.Results: In all evaluated phases, heart rate was significantly lower in balanced anaesthesia compared to monoinhalational anaesthesia, as well asresponse to skin incision. We did not observe any differences in mean arterial pressure or recovery time. Heart rate variability was comparable in bothtypes of anaesthesia.Conclusion: Balanced anaesthesia can be used even in the smallest infants without a risk for cardiovascular depression. Cardiovascular reactionto pain can be attenuated by administration of an opioid with rapid onset.

Key words:
newborn – opioids – cardiovascular stability – recovery time