The Study Of Preload/Coload Combined With Phenylephrine On Prevention Of Hypotension After Spinal Anesthesia During Cesarean Section

Objective To investigate the effect and security of preload/coload combined with on prevention of hypotension after spinal anesthesia during cesarean section.Methods Sixty cases of full-term singleton pregnant women undergoing elective cesarean section (ASA I or II,22-32years old, there was no significant difference among their height, weight, duration of gestation) were selected. The parturients were randomly divided into two groups with30cases each after those who were associated with pregnancy-induced hypertension, diabetes, cardiopulmonary disease, nerve damage, acidosis/alkalosis, fetal abnormalities, precious child were excluded:control group:ephedrine group (group E) and experimental group:phenylephrine group (group P). Maternal BP and HR were measured and recorded at3-minute intervals and the mean values were choosed as the basis of BP and HR after the parturients went into the operating room. Lactated Ringer’s solution was administered intravenously before induction of spinal anesthesia with6-8ml/kg (preload). Spinal anesthesia was performed with the parturients in the left lateral position at L2-3. The both groups were respectively given ephedrine5mg or phenylephrine100μg intravenously while puncture needle reachered the epidural space.0.5%bupivacaine7.5mg was administered cephalad through spinal needle to complete spinal anesthesia Hydroxyethyl Starch130/0.4and Sodium Chloride solution was administered intravenously at the time of induction of spinal anesthesia (coload) with10ml/kg. And, ephedrine or phenylephrine injection was given continuously with pump injection intravenously. The speed of the pump was adjusted to stabilize the blood pressure during the operation. The pump didn’t stop until the neonate was born. The blood gas analysis of maternal arterial blood and umbilical arterial blood were done immediately after the birth. The Apgar score was recorded at the time of lmin and5min after neonate was born.Results There was no statistically significant difference with the incidence intraoperative hypotension between the both groups; The values of pH and BE of umbilical arterial blood in group P were higher than those in group E (P<0.05).Conclusion preload/coload combined with ephedrine or phenylephrine can both reduce the incidence of maternal hypotension after spinal anesthesia; Compared with ephedrine, the use of phenylephrine reduced the risk of neonatal acidosis.