Observation of hemodynamic parameters using a non-invasive cardiac output monitor system to identify predictive indicators for post-spinal anesthesia hypotension in parturients undergoing cesarean section

Abstract

The administration of high-level spinal anesthesia for cesarean section may lead to significant hemodynamic changes. Bioreactance-based non-invasive cardiac output monitoring (NICOM™) provides an accurate monitoring system for parturients under spinal anesthesia. The present study hypothesized that baseline hemodynamic parameters obtained via the NICOM™ system could serve as predictive indicators for post-spinal anesthesia hypotension. Therefore, 80 full-term parturients with singleton pregnancies who underwent scheduled cesarean section were enrolled and allocated to either a supine position group or a 15˚ left tilt group. All parturients received standard pre-hydration with 750 ml of 0.9% saline. Baseline cardiac output index (CI), total peripheral resistance index (TPRI) and stroke volume (SV) were recorded using the NICOM™ system. Subsequently, spinal anesthesia with 2.4 ml of 0.5% hyperbaric bupivacaine, 10 µg of fentanyl and 0.2 mg of morphine was administered. Receiver operating characteristic (ROC) curves and multivariate logistic regression were used to analyze the data. A total of 40 parturients (51.9%) developed hypotension. The areas under the ROC curves were 0.666, 0.594 and 0.622 for the CI, TPRI and SV, respectively. The optimal cutoff value of the CI in predicting hypotension was 3.68 l/min/m 2 (ROC, sensitivity=85.0%, specificity=48.6%). Furthermore, CI was considered as an independent factor for post-spinal anesthesia hypotension. In conclusion, the baseline CI obtained via the bioreactance-based NICOM™ system may serve as a predictor of post-spinal anesthesia hypotension in parturients regardless of patient position.

Effect of different position on inferior vena cava dimensions and its influence on hemodynamics during cesarean section under combined spinal‐epidural anesthesia: A randomized controlled trial

“…They also found cardiac output increased in the 15° left operating table tilt. However, no such result was observed in the study of Yeh et al 30 The reason for this result might be a change in hemodynamic status caused by preperfusion of 750 mL 0.9% saline fluid.…”

Risk factors of more severe hypotension after spinal anesthesia for cesarean section

“…Compared to the parturients without SAIH, those with SAIH had a significantly lower baseline SBP (122 [interquartile range = 114-130] vs 130 [120-143] mmHg, p < 0.001), heavier large fetal weight (3098 [2742-3345] vs 2930 [2576-3266] g, p < 0.001), were more often multiparous (259 [60.4%] vs 261 [45.8%], p < 0.001), had a higher percent change in lowest SBP (33 [27-39] vs 19 [12][13][14][15][16][17][18][19][20][21][22][23][24][25]%, p < 0.001), and shorter time to lowest SBP after spinal anesthesia (14.9 [10][11][12][13][14][15][16][17][18][19][20] vs 15.9 [10][11][12][13][14][15][16][17][18][19][20] minutes, p < 0.001).…”

“…12,13 In a systematic review, 13 Yu et al classified the predictive factors of post-spinal anesthesia-induced hypotension (SAIH) into seven domains: demographic characteristics, baseline hemodynamic parameters, sympathovagal balance indices, postural stress testing, peripheral perfusion indices, blood volume and fluid responsiveness indices, and genetic polymorphisms. Most previous studies have focused on demographic characteristics such as maternal weight and body mass index (BMI) [14][15][16] and baseline hemodynamic parameters such as baseline heart rate (HR) 15 and baseline systolic blood pressure (SBP) [17][18][19] to predict post-SAIH, however the results have been inconclusive. Therefore, we conducted this retrospective study to investigate the factors associated with the need for higher doses of vasopressors in women undergoing cesarean section.…”

Prediction of spinal anesthesia-induced hypotension during elective cesarean section: a systematic review of prospective observational studies

“…Among them, only three reported a weak relationship between maternal weight and body mass index (BMI) with spinal anesthesia-induced hypotension. 19,25,26 Many more studies found no predictive value of BMI, maternal weight, height, or body roundness index. 5,11,14,16,18,21,[27][28][29] Ghabach et al 30 reported that maternal weight gain during pregnancy was valuable in predicting spinal anesthesia-induced hypotension, however the sensitivity was low (53.1%).…”

“…However, the predictive value of PVI in two studies was moderate (AUROC 0.6 and 0.75) (Supplementary Table 7), 28,38 and in three additional studies the PVI was not predictive of spinal anesthesia-induced hypotension. 17,19,23 Baseline cardiac output index, stroke volume (SV) 26 and cardiac output change during passive leg raise (PLR) test 12 were also not good predictors.…”