Effect of different crystalloid preload volumes combined with prophylactic norepinephrine infusion on inferior vena cava collapsibility index and post-spinal anesthesia hypotension during cesarean section: a randomized controlled trial

Vasopressor and fluid administration are important strategies to prevent and treat post-spinal anesthesia hypotension at cesarean section. 1 Practice guidelines for obstetric anesthesia: an updated report by the American Society of Anesthesiologists Task Force on obstetric anesthesia and the Society for Obstetric Anesthesia and Perinatology. Anesthesiology 2016;124:270-300. https://doi.org/10.1097/ALN.0000000000000935. Google Scholar , 2 Kinsella S.M. Carvalho B. Dyer R.A. et al. International consensus statement on the management of hypotension with vasopressors during caesarean section under spinal anaesthesia. Anaesthesia. 2018; 73: 71-92https://doi.org/10.1111/anae.14080 Crossref PubMed Scopus (185) Google Scholar As a principal strategy, vasopressors, especially α-adrenergic agonists, are used to counteract decreases in peripheral vascular resistance induced by sympathetic blockade. 3 Ngan Kee W.D. Lee S.W.Y. Ng F.F. et al. Prophylactic norepinephrine infusion for preventing hypotension during spinal anesthesia for cesarean delivery. Anesth Analg. 2018; 126: 1989-1994https://doi.org/10.1213/ANE.0000000000002243 Crossref PubMed Scopus (0) Google Scholar The inferior vena cava (IVC) collapsibility index (CI) is a useful measure with which to estimate cardiac preload and volume status. 4 Hernandez C.A. Reed K.L. Juneman E.B. et al. Changes in sonographically measured inferior vena caval diameter in response to fluid loading in term pregnancy. J Ultrasound Med. 2016; 35: 389-394https://doi.org/10.7863/ultra.15.04036 Crossref PubMed Scopus (10) Google Scholar In this study we investigated the effect of different crystalloid preload volumes combined with prophylactic norepinephrine infusion on IVC-CI and post-spinal anesthesia hypotension in patients undergoing cesarean section.