Can inferior vena cava respiratory variability be useful to predict hypotension and bradycardia during spinal anaesthesia in spontaneously breathing patients?

Abstract

Background. Hypotension and bradycardia are the most common hemodynamic disorders and side effects of spinal anaesthesia (SA) on the cardiovascular system [1]. SA-induced sympathetic denervation causes peripheral vasodilatation and redistribution of central blood volume that may lead to decreased venous return to the heart [2, 3]. The aim of the study was to evaluate the changes of inferior vena cava collapsibility index (IVC-CI) during spinal anaesthesia in spontaneously breathing patients undergoing knee arthroplasty surgery to prognose manifestation of intraoperative hypotension and bradycardia. Methods. 60 patients (American Society of Anesthesiologists (ASA) physical status I or II, no clinically significant cardiovascular pathology) of both sexes undergoing knee arthroplasty under SA were included in the prospective study. Inspiratory and expiratory inferior vena cava (IVCin, IVCex) diameters were measured using an ultrasound device in supine position before and immediately after SA, then 15 min, 30 min, and 45 min after SA was performed. The heart rate, along with systolic, diastolic, and mean arterial blood pressures were collected. The parameters were measured at the baseline and at the next four time points. Results. There were no significant changes in IVCin, IVCex, and IVC-CI compared to baseline and other time point measurements in hypotensive versus nonhypotensive and bradycardic versus nonbradycardic patients (p > 0.05). Changes in IVC diameter do not prognose hypotension and bradycardia during SA: the area under the curve (AUC) of the receiver operating characteristic (ROC) curve for IVC-CI at all measuring points was < 0.7, p > 0.05. Conclusions. Reduction in IVC diameters and increase in IVC-CI do not predict hypotension and bradycardia during SA in spontaneously breathing patients undergoing knee arthroplasty surgery. It seems SA does not affect circulating blood volume and heart preload by. [...].