Abstract

World J Pediatr. 2008 Feb;4(1):49-52.

Enflurane requirement for blocking adrenergic responses to incision in infants and children.

Authors: Wang X, Zhang XF.

Department ofAnesthesiology, Children's Hospital of Fudan University, 183 Fenglin Road, Shanghai 200032, China. Davidxwang@citiz.net.

Background
Enflurane is one of the most commonly used inhaled anesthetics in China, but its requirement to block adrenergic responses after skin incision in pediatric patients is still unknown. This study was to determine the minimum alveolar Anaesthetic concentration (MAC) of potent inhaled anesthetics required to blunt the adrenergic response to skin incision of enflurane (MACBAR) in infants and children.

Methods
Twenty-eight patients, 10 infants (6-12 months) and 18 young children (1-6 years), were studied. The 18 children were randomly assigned into two groups, with or without fentanyl. Anesthesia was induced with 3 mg/kg propofol and 0.15 mg/kg vecuronium, and maintained with enflurane in 100% oxygen. Fentanyl (3 microg/kg) was given intravenously 5 minutes before incision for the patients of fentanyl group. The "up and down" method (with 0.3 MAC as a step size and 1 MAC as the start dose) was applied to determine MACBAR. The response was considered positive if the mean arterial pressure (MAP) or heart rate (HR) increased > or =15% after incision. The MACBAR was calculated as the mean of four independent cross-over responses in each group.

Results
MACBAR of enflurane in children of 1-6 years old was 3.2% (95% CI, 2.8%-3.6%) and was reduced to 2.2% (95% CI, 1.8%-2.5%) by 3 microg/kg fentanyl. In infants of 6-12 months old, the MACBAR of enflurane was 3.4% (95% CI, 3.0%-3.8%).

Conclusions
MACBAR of enflurane in infants older than 6 months is similar to that in young children. The MACBAR of enflurane decreases with co-administration of fentanyl in the pediatric population.

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Ann Card Anaesth. 1999 Jan;2(1):15-21.

Coronary Artery Bypass Grafting without Cardiopulmonary Bypass: Improvement in Cardiac Function Following Enflurane Anaesthesia during Coronary Occlusion.

Authors: Gozal Y, Elami A, Milgalter E, Merin G, Drenger B.

Department of Anaesthesiology and Critical Care Medicine, Hadassah University Hospital, Jerusalem, Israel. gozaly@md2.huji.ac.il.

Severe adverse effects, especially neurologic complications after cardiopulmonary bypass have lead to the development of techniques for performing coronary artery bypass graft surgery without cardiopulmonary bypass. Laboratory and clinical studies confirmed the positive role of enflurane anaesthesia in preventing myocardial dysfunction following an ischaemic interval.

The aim of this study was to evaluate the haemodynamic response to enflurane anaesthesia during single graft coronary bypass surgery without cardiopulmonary bypass. Twenty one patients were divided randomly into two groups: control and enflurane groups. Haemodynamic parameters and those derived from a pulmonary artery catheter were recorded and analysed. In the enflurane group, the amount of fentanyl administered was considerably less than in the control group: 25.7 +/- 3.8 microg/kg vs 36.8 +/- 1.6; p=0.03. The mean arterial pressure during enflurane administration was lower than in control group, but the difference was not significant. Despite a dearease in left ventricular function during the performance of the anastomosis in the enflurane group, a significant recovery was noted after 20 minutes of reperfusion: cardiac index increased from 1.4 +/- 0.1 to 1.85 +/- 0.1 L/min/m2 and left ventricular stroke work index from 15.8 +/- 1.1 to 27.7 +/- 6.7 g.m.m2 . In the control group, the deterioration in cardiac function observed during the graft anastomosis did not recover till the end of the surgical procedure.

We conclude that enflurane anaesthesia may be a positive addition to fentanyl-based anaesthesia by improving myocardial function following CABG without bypass surgery.