Comparison of the effect of 5 and 10 μg bolus doses of intravenous norepinephrine on the prevention of hypotension after spinal anesthesia with 0.5% bupivacaine in cesarean section: a double-blind randomized clinical trial

Determining and comparing the effect of 5 and 10 μg bolus doses of intravenous norepinephrine on the prevention of hypotension after spinal anesthesia with 0.5% bupivacaine in cesarean section: a double-blind randomized clinical trial

This clinical trial with a control group with parallel, double-blind, randomized, phase 2-3 groups was performed on 126 pregnant patients aged 18-46 years who were candidates for cesarean section and randomization block was used for randomization.

Immediately after spinal anesthesia, 42 patients received 5 micrograms of norepinephrine, 42 patients received 10 micrograms of norepinephrine, and 42 patients received 1 ml of normal saline intravenously, then systolic and diastolic blood pressure, mean arterial pressure and heart rate are measured and recorded every two minutes to 10 minutes, then every 5 minutes to 15 minutes and then every 10 minutes until the end of the operation.

Inclusion Criteria: Satisfaction to participate in the project; Pregnant patients 18 to 46 years old; Term pregnancy and a candidate for cesarean section under spinal anesthesia. Exclusion Criteria: No spinal anesthesia and induce general anesthesia; Existence of lung and heart diseases and fever; Emergency cesarean section; Eclampsia and preeclampsia; Multiple pregnancies; Contraindications to spinal anesthesia; History of taking ergotamine and an initial systolic pressure of less than 90 mmHg.

Immediately after spinal anesthesia, patients in groupA, 5 microgram of norepinephrine ( volume of 1 ml) and in group B, 10 micrograms of norepinephrine ( volume of 1 ml) and in group C 1 ml of normal saline as a control group, injected intravenously.

Hypotension

In this study, Block Randomization method is used as 6 blocks for randomization. In this way, we put 6 pieces of paper with the letter A and 6 pieces of paper with the letter B and 6 pieces of paper with the letter C in a bag and mix them, then for each patient that enters the study, one of the papers is taken out randomly and will be assigned to one of the three groups: A (norepinephrine 5 micrograms), B (norepinephrine 10 micrograms) and group C (normal saline), depending on whether the drawn sheet is either A , B or C. Then, for the next series of patients, the papers are returned to the bag and the same process is repeated until the end of the sample volume.

Immediately after spinal anesthesia in group A, 5 micrograms of intravenous norepinephrine ( 1 ml), in group B, 10 micrograms of intravenous norepinephrine ( 1 ml) and in group C, 1 ml normal saline as a control group In similar syringes , which are pre-specified by the anesthesia nurse according to the list, are prepared and injected intravenously.