Comparison of Hydroxyethyl Starch and Crystalloid Coload Combined With Norepinephrine Infusion for Hypotension

Comparison of Hydroxyethyl Starch and Crystalloid Coload Combined With Norepinephrine Infusion for Hypotension

Comparison of 6% Hydroxyethyl Starch (130/0.4) and Crystalloid Coload Combined With Prophylactic Norepinephrine Infusion for Postspinal Anesthesia Hypotension in Patients Undergoing Caesarean Section

The purpose of this study is to investigate the ED50 and ED90 for an effective 6% Hydroxyethyl starch (130/0.4) or crystalloid coload combined with prophylactic norepinephrine infusion dose for postspinal anesthesia hypotension in patients undergoing cesarean section.

Post-spinal anesthesia hypotension is a frequent complication during spinal anesthesia for cesarean section. The incidence of post-spinal anesthesia hypotension is as high as 62.1-89.7% if prophylactic measures are not taken. Colloid fluid coload has been highly demonstrated for prevention and/or treatment of post-spinal anesthesia hypotension. In addition, there's some evidence that prophylactic infusion of norepinephrine could effectively reduce the incidence of post-spinal anesthesia hypotension in parturients undergoing cesarean section. However, the ED50 and ED90 for an effective 6% Hydroxyethyl starch (130/0.4) or crystalloid coload combined with prophylactic norepinephrine infusion dose for postspinal anesthesia hypotension is still unknown. The purpose of this study is to investigate the ED50 and ED90 for an effective 6% Hydroxyethyl starch (130/0.4) or crystalloid coload combined with prophylactic norepinephrine infusion dose for postspinal anesthesia hypotension in patients undergoing cesarean section.

Crystalloid, Hydroxyethyl starch 130/0.4, Postspinal anesthesia hypotension, Cesarean section, Norepinephrine, Coload

10 ml/kg 6% Hydroxyethyl starch (130/0.4) coload combined with an initial infusion dose of prophylactic norepinephrine simultaneous with spinal anesthesia

10 ml/kg crystalloid coload combined with an initial infusion dose of prophylactic norepinephrine simultaneous with spinal anesthesia.

10 ml/kg 6% Hydroxyethyl starch (130/0.4) coload combined with an initial infusion dose of prophylactic norepinephrine (0.025 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.005 ug/kg/min of prophylactic norepinephrine according to the responses of previous patients according to the up-down sequential allocation.

10 ml/kg crystalloid coload combined with an initial infusion dose of prophylactic norepinephrine (0.025 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.005 ug/kg/min of prophylactic norepinephrine according to the responses of previous patients according to the up-down sequential allocation.

The dose of prophylactic norepinephrine combined with 10 ml/kg 6% Hydroxyethyl starch (130/0.4) or 10 ml/kg crystalloid coload that would be effective in preventing postspinal anesthesia hypotension in 50% (effective dose, ED 50) and 90% (ED90) of patients

Inclusion Criteria: 18-40 years Primipara or multipara Singleton pregnancy ≥ 37 weeks American Society of Anesthesiologists physical status classification I to II Scheduled for elective cesarean section under spinal anesthesia Exclusion Criteria: Body height < 150 cm Body weight > 100 kg or body mass index (BMI) ≥ 40 kg/m2 Eclampsia or chronic hypertension or baseline blood pressure ≥ 160mmHg Hemoglobin < 7g/dl Coagulation or renal function disorders Known allergy to hydroxyethyl starch Fetal distress, or known fetal developmental anomaly