Norepinephrine as Hemodynamic Maintenance in Caesarian Delivery Under Spinal Anesthesia

Patients scheduled for routine elective cesarean section under combined spinal epidural anesthesia (CSE)will be enrolled in this double-blind, randomized controlled trial, As standard of care for cesarean section procedure, a preoperative anesthetic consultation is performed. If the patient is eligible for enrollment, she will be provided with detailed information regarding the study and asked to sign Informed Consent. Participants are allocated to one of two groups: Group A will receive a CSE anesthesia with 7,5 milligrams (mg)hyperbaric Marcaine and 2,5 microgram (mcg)Sufentanil.

Group B will receive a CSE anesthesia as well with 10 mg hyperbaric Marcaine and 2,5 mcg Sufentanil. At the University Hospital Antwerp, Group A is standard of care for cesarean section. In case of insufficient pain relief an extra bolus of local anesthesia through the epidural catheter can be administered in both groups. In this trial we use a double blinding principle. Both the patient and the observant/study physician are fully blinded. To maintain blinding of the study, two anesthesiologists are involved in this trial. The first anesthesiologist will perform randomization by means of Redcap software and will prepare study medication according to allocation to group A or B just before start of spinal anesthesia. He /she is responsible for the placement of neuraxial block and the spinal epidural catheter. As part of routine care anesthesia an intravenous line with 500 milliliter (ml) Plasmalyte (minimal 20 Gauche catheter) will be established in both groups . Standard monitoring (blood pressure, Electrocardiogram and Oxygen saturation) will be applied.

A baseline systolic blood pressure will be measured as a mean of 3 consecutive measurements before start of CSE and is defined as baseline blood pressure.

Blood pressure will be measured every 1 minute. To maintain normotension during the procedure a continuous infusion of norepinephrine will be given at 15 milliliter/hour through the peripheral intravenous (IV)catheter in both groups. Therefore a solution of norepinephrine in a concentration of 10mcg/ml in a 50ml syringe is prepared and connected to the peripheral IV line, most proximal to the IV catheter. A combined spinal epidural puncture will be performed in the sitting position at the level of Lumbal (L)2-L3 or L3-L4 with a CSE needle set (18 Gauge Tuohy needle, 27 Gauge pencil point needle, 18 gauge catheter, Braun).

After placing the 18-gauge Tuohy needle in the epidural space, confirmed by loss of resistance with natriumchloride (NaCl) 0,9 percent (%), the spinal 27-gauge pencil point needle is advanced until it reaches the subarachnoidal space. Once the wright needle tip position is confirmed by back flow of cerebrospinal fluid (CSF), the local anesthetic solution will be injected in 15 seconds with the spinal needle orifice facing cephalad. Immediate after injection the epidural catheter will be inserted and placed at a distance of 5 cm beyond the Tuohy needle tip. Afterwards the patient is turned to the supine position A left lateral tilt (30%) will be applied to the operating table.