Pre-operative Ultrasonographic Evaluation of the Internal Jugular Vein Collapsibility Index and Inferior Vena Cava Collapsibility Index to Predict Post Spinal Hypotension in Pregnant Women Undergoing Caesarean Section

Postspinal hypotension (PSH) is common in obstetric anesthesia practice, with an incidence of up to 71 %. PSH can occur precipitously and, if severe, can result in both maternal and fetal/neonatal adverse events. Pregnant women with predelivery hypovolemia are at risk of cardiovascular collapse and the sympathetic blockade may severely decrease venous return. Hence, prevention of PSH is an essential element in obstetric anesthesia and fasting for aspiration prophylaxis may further add up to the hypovolemia for the patients not on maintenance fluids.

Hemodynamic monitoring in obstetric patients has evolved during the last decade, with the development of minimally invasive and noninvasive continuous cardiac output (CO) monitors. Ultrasound (USG) is a method for noninvasive hemodynamic optimization in the ICU and ED, and it may be more helpful than other noninvasive methods. Transabdominal USG measurements of inferior vena cava (IVC) are noninvasive and thus are not associated with complications. USG of the IVC diameter is a useful and easy method for assessing a patient's volume status by calculating the IVC collapsibility index (IVCCI).

Recently, the usefulness of point-of-care ultrasonographic examination, performed by anesthesiologists in real time, for perioperative management has been reported . Ultrasonographic studies have established the utility of measuring the inferior vena cava (IVC) or internal jugular Vein (IJV) for evaluating intravascular volume status .

In particular, IVC diameter and collapsibility, obtained from ultrasonographic measurement, have been demonstrated to be predictors of hypotension after anesthetic administration.