ED90 of Norepinephrine and Phenylephrine Boluses Under Intensive Treatment in Preeclamptic Patients

An initial infusion dose of prophylactic norepinephrine (6 ug) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 1 ug of prophylactic norepinephrine according to the responses of previous patients according to the up-down sequential allocation.

An initial infusion dose of prophylactic phenylephrine (75 ug) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 12.5 ug of prophylactic phenylephrine according to the responses of previous patients according to the up-down sequential allocation.