CONTINUOUS ESOPHAGEAL AORTIC BLOOD-FLOW ECHO-DOPPLER MEASUREMENT DURING GENERAL-ANESTHESIA IN INFANTS

Purpose: Invasive haemodynamic monitoring during general anaesthesia i n infants is usually limited to very high risk operations, such as car diac surgery. Nevertheless, different surgical procedures and/or anaes thetic techniques justify additional monitoring for children, as for a dults. The aim of this preliminary study was to evaluate the feasibili ty of using a new echo-Doppler device (Dynemo 3000(R)) capable of meas uring continuous aortic blood flow during general anaesthesia in infan ts. Methods: Aortic blood flow (ABF) was measured with a small oesopha geal probe designed for newborns and infants. The aortic flowmeter was connected with satellite devices to visualise the haemodynamic profil e which included ABF; pre-ejection period (PEPi), left ventricular eje ction time (LVETi), mean arterial pressure, heart rate, stroke volume and systemic vascular resistance. Twelve infants, aged 8-26 mo, underg oing surgery under general anaesthesia were successively included in t he evaluation of this device. Isoflurane (1% end-expired concentration ) was introduced to maintain anaesthesia after induction with halothan e, midazolam, fentanyl and atracurium. Results: Correct positioning of the probe was easily obtained in all cases and the recording quality was excellent, whatever the operative position. Recordings of haemodyn amic data showed some myocardial depression from isoflurane: decreased ABF (indexed to body surface area) and lengthened PEP/LVET (2.24 +/- 0.53 L.min(-1).m(-2) and 0.32 +/- 0.05 respectively, before introducti on of isoflurane and 1.71 +/- 0.53 L.min(-1).m(-2) (P = 0.027) and 0.3 9 +/- 0.06 (P = 0.007) with isoflurane). Conclusion: These preliminary results suggest that this continuous ABF echo-Doppler device may be v aluable for peri anaesthetic monitoring in infants.