[A case report of a patient who developed cyanosis and significant decrease in PtcO2 caused by a contraction of the...

A 2-day-old male baby with patent ductus arteriosus and pulmonary atresia had an emergency anoplasty because of anal atresia. During the operation, anesthesia was maintained satisfactorily with 1-2% halothane and 70% nitrous oxide in oxygen, accompanied with continuous infusion of prostaglandin E1 (PGE1). However, after the inspired oxygen concentration was changed to 100% from 30% at the end of the operation, transcutaneous partial pressure of oxygen (PtcO2) began to decrease progressively, developing cyanosis and sinus bradycardia. Immediately the inspiratory concentration of oxygen was returned to 30% from 100% and the infusion rate of PGE1 was increased from 2 micrograms. kg-1.min-1. Atropine 0.2mg was also administered intravenously. A few minutes after this therapy, a gradual increase in PtcO2 was observed, and he recovered from cyanosis and respiratory arrest. In this case, we suspect that the cyanosis developed because of the contraction of PDA. In summary, anesthetic management of a patient with pulmonary atresia and PDA is described. The PtcO2 should be monitored continuously and the inspiration of pure oxygen should be avoided. Continuous infusion of PGE1 may be one of the effective measures to dilate PDA.