[Extracorporeal membrane oxygenation in critically ill neonates and children]

Extracorporeal membrane oxygenation is used as a last resort during neonatal and pediatric resuscitation in case of refractory circulatory or respiratory failure under maximum conventional therapies. Different types of ECMO can be used depending on the initial failure. The main indications for ECMO are refractory respiratory failure (acute respiratory distress syndrome, status asthmaticus, severe pneumonia, meconium aspiration syndrome, pulmonary hypertension) and refractory circulatory failure (cardiogenic shock, septic shock, refractory cardiac arrest). The main contraindications are a gestational age under 34 weeks or birth weight under 2kg, severe underlying pulmonary disease, severe immune deficiency, a neurodegenerative disease and hereditary disease of hemostasis. Neurological impairment can occur during ECMO (cranial hemorrhage, seizure or stroke). Nosocomial infections and acute kidney injury are also frequent complications of ECMO. The overall survival rate of ECMO is about 60 %. This survival rate can change depending on the initial disease: from 80 % for meconium aspiration syndrome to less than 10 % for out-of-hospital refractory cardiac arrest. Recently, mobile ECMO units have been created. These units are able to perform ECMO out of a referral center for untransportable critically ill patients.

[Complete atrioventricular block, a possible complication of radiofrequency ablation of reciprocating nodal tachycardia]

Radiofrequency ablation of the slow pathway of the reentry circuit is the usual radical treatment of nodal tachycardia. It is, however, possible to create atrioventricular conduction defects, the significance of which is not known. The aim on this study was to report the history of these conduction defects created during ablation of the slow pathway of the intranodal reentry circuit. Four cases were observed in a series of 27 patients. In one female patient, complete atrioventricular block was observed for 5 minutes before conduction returned to normal followed by recurrence of the tachycardias. Three other women developed complete atrioventricular block one to four days after the ablation. The block regressed after a maximum delay of 7 days. Six months to one year after the procedure, these three patients remain free of tachycardia and have only first degree atrioventricular block on the surface ECG. These patients were not implanted with a pacemaker. The authors conclude that complete atrioventricular block after ablation of the slow pathway may be treated conservatively, providing it is well tolerated. It normally regresses within few days.