Closure of persistently patent arterial duct and its impact on cerebral circulatory haemodynamics in children.
OBJECTIVE
Closure of a patent arterial duct (PDA) is suggested as a risk factor associated with intraventricular haemorrhage and/or cerebral ischemia in neonates. This study evaluate the effects of transcatheter closure of a patent arterial duct in children on cerebral blood flow velocity.


METHODS
Twelve children, aged from one to eight years were enrolled. Anaesthesia induction consisted of thiopentone, fentanyl and diazepam. Tracheal intubation was facilitated with vecuronium. Anaesthesia was maintained with N2O 70% in O2 and a PaCO2 between 35 to 40 mmHg. No cerebral vasoactive agents were used. Mean arterial pressure (MAP), central venous pressure (CVP), heart rate were continuously recorded. Systolic (Vs) and diastolic (Vd) cerebral blood flow velocity (CBFV) were recorded. Cerebral perfusion pressure (CPP) was calculated. The mean CBFV, the systolic-mean ratio and the cerebral blood volume were estimated from the area under the velocity-time curve (AUC) before PDA closure, immediately after and for 10 min following occlusion.


RESULTS
The mean (+/- SD) age and weight were 30 +/- 22 mo and 13 +/- 5 kg, respectively. Continuous recording during duct closure showed an abrupt increase in Vd (P < 0.05) whereas Vs remained constant. The AUC increased after closure and persisted for 10 min (P < 0.05).


CONCLUSIONS
This study confirms that closure of a PDA leads to acute changes in intracerebral diastolic flow and volume. This observation gives weight to mechanisms involved in IVH in smaller infants after arterial surgical duct closure. The anaesthetic technique used for arterial duct closure in these procedure could influence these observations.
Bissonnette
B
B
Department of Anaesthesia, Hospital for Sick Children, University of Toronto, School of Medicine, Ontario, Canada. bruno@anaes.sickkids.on.ca
Benson
L N
LN
D019540:Area Under Curve; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D004374:Ductus Arteriosus, Patent / Q000503:physiopathology* / Q000601:surgery; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007223:Infant; D008991:Monitoring, Physiologic; D014159:Transducers; D017585:Ultrasonography, Doppler, Transcranial