Comparison Between Hypertonic Saline (3%) and Normal Saline (0.9%) as a Preload Before Spinal Anaesthesia in Caesarean Section

Abstract

pinal anesthesia is frequently used for cesarean delivery because of its rapid onset, a dense neural block, little risk of local anesthetic toxicity and minimal transfer of drug to the fetus. General anesthesia is preferred in emergency obstetric situations, such as cord prolapse, in which there is a need for reliable induction, and also bleeding placenta previa. Unfortunately It is frequently accompanied by hypotension, which may be defined in absolute terms as a systolic blood pressure (SBP) of 90 or 100 mmHg or in relative terms as a percentage (20% fall from baseline). One of the ways to overcome this problem is to use fluids as a preload before spinal anesthesia. This preloading with intravenous fluids offset the vasodilating effects of sympathetectomy caused by spinal anaesthesia thereby maintaining the venous return and thus the drop in blood pressure is prevented. Hypertonic saline can be used as a preload before spinal anesthesia as it causes marked osmotic shift of fluid from the intracellular to the interstitial and intravascular space thus maintains intravascular volume and prevents spinal induced hypotension.