Comparative Efficacy Of Crystalloid Coloading And Preloading For Hypotension Prophylaxis In Spinal Anesthesia For Cesarean Delivery

Section AObjective: To determine whether crystalloid infusion just after intrathecal injection(coload)would be better than infusion before anesthesia(preload)for hypotension prophylaxis in spinal anesthesia for cesarean delivery.Methods: We searched Pub Med,EMBASE,Cochrane Central Register of Controlled Trials and other databases for randomized controlled trials comparing coload of crystalloid with preload in parturients receiving spinal anesthesia for cesarean delivery.The key word was "cesarean delivery","fluid therapy","crystalloid","preloaded","coload" and "randomized controlled trials".Primary outcome was intraoperative incidence of hypotension.Other outcomes were intraoperative need for vasopressors,hemodynamic variables,neonatal outcomes(umbilical artery p H and Apgar scores),and the incidence of maternal nausea and vomiting.We used Revman 5.2 and STATA 12.0 for the data analyses.Results: Ten studies with 824 cases were included.The incidence of hypotension was significantly higher in the preload group compared with the coload group(57.8% vs 47.1%,odds ratio [OR] = 1.62,95% confidence interval [CI] = 1.11–2.37,P = 0.01).More patients needed intraoperative vasopressors(OR = 1.71,95% CI = 1.07–2.04,P = 0.02)when receiving crystalloid preload.In addition,the incidence of nausea and vomiting was higher in the preload group(OR = 3.40,95% CI = 1.88–6.16,P < 0.0001).There were no differences in neonatal outcomes between the groups.Conclusions: For parturients receiving crystalloids loading in cesarean delivery under spinal anesthesia,coload strategy is more effective than preload for the prevention of maternal hypotension.Section BObjective: In the clinical practice,we observed the efficacy of different crystalloids fluid management solutions(crystalloid preloading and coloading)during spinal anesthesia for elective caesarean section to determine optimal crystalloids infusion scheme.Methods:The prospective randomized study was carried out in 12 parturient aged from 20 to 35 years with term singleton normal pregnancy of ASA physical status I and II undergoing elective lower segment caesarean section under spinal anaesthesia.They were randomly divided into 2 groups: preload/P group(n = 6)and the coload/C group(n = 6).Group P(preload group)was received 15ml/kg of lactated ringer's solution during 20 minutes prior to induction of spinal anaesthesia,while group C(coload group)was received equivalent volume by rapid infusion after administration of the local anaesthetic intrathecally.Both group received RL at the rate of 10 to 15 drops/min after repidy infusion.Incidence of hypotension,requirement of mephenteramine,heart rate(HR),diastolic blood pressure(SBP),systolic blood pressure(DBP),percutaneous oxygen partial pressure(Ptc O2),percutaneous carbon dioxide partial pressure(Ptc CO2),neonatal outcome-Apgar score,umbilical vein(PH,BE)were recorded.Results: Our study included 12 participants,preload/P group(n = 6)and coload /C group(n = 6).In this study,we compared the preoperative and postoperative urine,hemoglobin and hematokrit,only postoperative urine volume in the two groups had statistical difference(P = 0.02),and preoperative and delta urine output during the operation in the two groups had no statistical difference.The intraoperative adverse events including the incidence of hypotension,requirement of intraoperative vasopressors and the incidence rate of intraoperative nausea and vomiting,hemodynamic changes and neonatal outcome in the two groups all had no significant statistical difference.Conclusions:There can be no benefit on different timing of crystalloids administration.However,the sample size in our study was so small and further studies with larger sample size need to be done to make our conclusion more definite.