Maternal and fetal effects of intravenous patient-controlled fentanyl analgesia during labour in a thrombocytopenic parturient

Abstract

The use of intravenous (iv) patient-controlled fentanyl analgesia during labour in a parturient with unexplained thrombocytopenia (70 × 103 · ml-1) is described. The patient self-administered boluses of 25 μg of fentanyl with a lock-out interval often min. In addition, a concurrent fentanyl infusion of 25 μg · hr-1 was given. Effective analgesia was achieved during labour and a total of 1025 μg of fentanyl was infused over 11 hr 55 min until delivery of a vigorous infant with Apgar scores of 9 after one and five min. Respiratory depression or undue sedation were not observed in the mother either during labour or in the post-partum period. At birth, maternal total plasma fentanyl concentration was 1.11 ng · ml-1, whereas neonatal umbilical total plasma fentanyl concentration was 0.43 ng · ml-1. Newborn plasma protein binding of fentanyl was lower compared to the mother (63% vs 89%). Thus, free fentanyl concentrations (0.16 ng · ml-1) were identical in the mother and newborn at delivery. © 1992 Canadian Anesthesiologists.