Effect of Vasopressors on Spinal Anaesthesia Induced Hypotension

Comparison of the Effect of Epinephrine, Norepinephrine and Phenylephrine on Spinal Anesthesia Induced Hypotension

160 pregnant patients will be enrolled in this study. Participants will divide in to 4 groups. Spinal anaesthesia will perform with 5% marcain heavy 2 ml+20 microgram fentanyl to the all patients. After performed spinal anaesthesia, vasopressor infusion will be started intravenously. Epinephrine will prepare 5 mg/ml and infusion rate will adjust 30 ml/h for Group E. Norepinephrine will prepare 5 mg/ml and infusion rate will adjust 30 ml/h for Group NE and 0.9% saline (group S) was launched immediately after induction of spinal anesthesia. Phenylephrine will prepare 100 microg/ml and infusion rate will adjust 30 ml/h for Group P. If systolic blood pressure decrease 20% of basal value or below to 100 mmHg, bolus ephedrine will apply intravenously (IV). If heart rate will decrease 60 beat per min or 20% of basal value, atropine will apply IV.

After approved informed consent, 160 pregnant (term) patients with American society of anaesthesiologist (ASA) physiological status I-II will include this prospective, randomized clinical study. For randomisation of participants, computerized randomisation programme will use and they will divide into 4 groups. Basal value of systolic blood pressure(SBP) and heart rate (HR) will calculate with mean of the measure of 3 time SBP and HR before spinal anaesthesia. Spinal anaesthesia will perform with 5% marcain heavy 2 ml+20 microgram fentanyl at the point of lumbar 3-4 or 4-5 interspinous space to the all patients. After performed spinal anaesthesia, vasopressor infusion will start intravenously. Epinephrine, norepinephrine and phenylephrine will use for vasopressor infusion. Epinephrine will prepare 5 mg/ml and infusion rate will adjust 30 ml/h for Group E. Norepinephrine will prepare 5 mg/ml and infusion rate will adjust 30 ml/h for Group NE. Phenylephrine will prepare 100 microg/ml and infusion rate will adjust 30 ml/h for Group P. salin infusion will launch 30 ml/h for group Salin. If systolic blood pressure decrease 20% of basal value or below to 100 mmHg, bolus ephedrine will apply intravenously (IV) for rescue drug. If heart rate will decrease 60 beat per min or 20% of basal value, atropine will apply IV. At the end of the study all collected data will use for statistically analysis.

The incidence of hypotension (described as less than 80% of baseline (prenatal) SBP or SBP <90 mm Hg), the total number of hypotension episodes during surgery

At the time from start of vasopressor infusion till the end of surgery. The time frame is approximately 1 hour, peroperatively.

Inclusion Criteria: ASA I-II physical status Pregnant patients Full term pregnant Exclusion Criteria: ASA III-IV physical status Emergency status Heart disease Hypertension Body mass index>25