Changes in Cardiac Output During Cesarean Delivery Under Spinal Anesthesia

Measurement of cardiac output in supine position with left lateral tilt at baseline, at 10 minutes after intrathecal injection, immediately after delivery, and at 1 hour after intrathecal injection

Performed at the L3-L4 or L4-L5 interspace using 25-gauge spinal needle

Bupivacaine 12.5 mg (2.5 mL 0.5%) will be administered in the subarachnoid space

Fentanyl 15 μg will be administered in the subarachnoid space

Ringer acetate 1000 mL will be administered over 10 minutes starting immediately after intrathecal injection

Lower segment cesarean section using the Pfannenstiel incision and uterine exteriorization

Intravenous ephedrine 3, 5, and 10 mg will be administered when Systolic blood pressure decreases below 90%, 80%, and 70% of baseline, respectively.

Intravenous oxytocin 10 U in 500 mL Ringer acetate will be administered over 30 minutes starting immediately after delivery of the fetus