| Objective:To observe the different effects of the position intervention and application of ephedrine or methoxamine for curing hypotension and the influence on the fetus during cesarean section under coload and combined spinal-epidural anesthesia,it is attempted to find the effective way that was used to prevent and treat hypotension.Methods:90cases ASA I or II,monocyesis,head delivery,gestational weeks of34to41,aged25to35years old,body weigh65to85kg,body height155cm to170cm,no other complications,randomly divided into three groups (each group n=30):ephedrine group (group E),methoxamine group (group M), position group (group T).Anesthesia methods:All patients should execute the6h of preoperative fasting and don’t use routine preoperative medication including atropine and luminal sodium.Patients were monitored electrocardiogram,blood pressure,heart rate,oxygen saturation,and build up vein thoroughfare of upper limb.Lactated Ringer’s solution began instillation before induction of anesthesia and was infused in20ml/min rate during induction of anesthesia until the baby was produced.The patients laid on right lateral decubitus.The L3.4interspace were selected for puncture of combined spinal-epidural. After the cerebrospinal fluid outflow,isobaric solution of0.5%ropivacaine (1%ropivacaine+equal volume0.9%sodium chloride injection) was injected through the needle with the hole toward head at the rate of0.2ml/s.The dosage was selected according to maternal height,2.2ml for155～160cm,2.4ml for161-165cm and2.6ml for166-170cm.When the injection was completed,the needle was excluded.A catheter was placed into the epidural space toward the head3.5cm and supine position was restored.The body position of patients was adjusted according to the test requirements. During operation local anesthetic was added in epidural space according to the level of block. The highest level of block was controlled at T6-T8. After induction of spinal anaesthesia,all of three groups adopted left-leaning oblique position.Hypotension defined as systolic blood pressure<100mmHg or80%of the baseline.Coload+ephedrine group (group E):Immediately bolus injection of ephedrine10mg was adopted after injection of local anesthetics. When hypotension happened, assistant immediately lapse uterus to the left of body.If hypotension failed to be corrected, bolus injection of ephedrine10mg was adopted intermittently. Coload+methoxamine group (group M):Immediately bolus injection of methoxamine2mg was adopted after injection of local anesthetics. When hypotension happened, assistant immediately lapse uterus to the left of body.If hypotension failed to be corrected, bolus injection of methoxamine2mg was adopted intermittently. Coload+position group (group T):assistant immediately taked uterus to the left of body after injection of local anesthetics.If hypotension failed to be corrected, bolus injection of ephedrine10mg was adopted intermittently. When maternal heart rate<60/min, bolus injection of atropine0.3-0.5mg was adoped in three groups.Patients were inhalansed oxygen with face mask continuously during operation.The blood pressure and heart rate were monitored and recorded at before anesthesia(To),1minutes after spinal anesthesia(T1),2minutes (T2),3minutes (T3),5minutes (T4),10minutes (T5),15minutes (T6),20minutes (T7). After delivery, samples of umbilical arterial (UA) blood were taken immediately from a double-clamped segment of cord near foetus. The1ml umbilical artery blood was extracted with heparinized syringe, for measuring the PH,BE value. Recorded the Aparg score after delivery of the neonate in1minutes,5minutes and induction-delivery interval. We observed the highest sensory block level using pinprick and evaluated the condition of lower limb motor block using improved Bromage;We recorded intraoperative nausea,vomiting,hypotension, postural intervention and the times of using vasopressors.Results:There was no statistical significant difference in the age, height, weight among the three groups (P>0.05).There was no statistical significant difference in blood pressure and heart rate among the three groups (P>0.05).There was no statistical significant difference in PH, BE of umbilical artery blood and neonatal Apgar score of1minutes,and5minutes among the three groups,no changes were observed induction-delivery interval among the three groups(P>0.05).There was no statistical significant difference in the condition of lower limb motor block from improved Bromage,evaluation of pain,muscle relaxant extent and degree of traction reaction among the three groups (P>0.05).There was a significant difference in nausea, vomiting, hypotension and the times of using vasopressors among the three groups (P<0.05).Conclusion:For the elective cesarean section,position intervention can significantly reduce the incidence of hypotension when the quantity sufficient isobaric ropivacaine was used in combined spinal-epidural anesthesia under instantly expanding blood volume (coload),but can not completely eliminate the occurrence of hypotension. Vasopressors were required when severe hypotension occurred. |
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