Introduction Infants suffering from biliary atresia commonly undergo hepatoportoenterostomy (Kasai procedure) without cardiac output (CO) monitoring and with only a central venous pressure (CVP) catheter to guide fluid requirements. Aim is to evaluate non-invasive electrical bioimpedance cardiometry (EC) compared to minimally invasive transoesophageal Doppler (TED) for CO monitoring and fluid management and relationship with CVP. Material and methods A prospective randomized controlled study. 42 infants: TED (n=21), and EC (n=21). Intravenous fluids were guided by stroke volume variation (SVV) (%) of EC and corrected flow time (FTc) (msec) of TED with CVP monitored in all. Results Median [Interquartile] age (74 [58-86] vs. 73 [62-80] days, p=0.56), weight, (5.0 [4.2-5.2] vs. 5.0 [5.0-5.5] kg, p=0.11), operative time 6[5-6] vs. 6[5-6] hours (h) p=0.47) and crystalloids intake (300[275-330] vs. 300[270-336] ml, p=0.59) in EC and TED respectively. EC CO was constantly higher than TED CO (l/min) 0.95[0.87-1.2] vs. 0.9[0.7-1.1] p=0.001 and 1.02[0.87-1.31] vs. 0.8[0.7-1.25], p=0.001, post-induction and mid-surgery respectively. A good degree of reliability between TED and EC CO: post-induction, (Intra-class correlation (ICC)=0.693, p<0.001), 1st h (ICC=0.744, p<0.001), 2nd h (ICC=0.739, p<0.001), 3rd h (ICC=0.769, p<0.001) and 4th h (ICC=0.617, p=0.002). Bland and Altman analysis of CO (l/min) between EC and TED showed reasonable bias [mean] but broad limits of agreement (+/- 2 SD): Post-induction: 0.122 (0.636 to -0.391), 1st h 1: 0.147 (0.605 to -0.310), 2nd h: 0.130 (0.616 to -0.356), 3rd h: 0.162 (0.578 to -0.253), 4th h: 0.172 (0.724 to -0.379). FTc negatively correlated with SVV and CVP. Conclusions Both methods were able to monitor the trend changes of CO and equally guide fluid management, with a good degree of reliability, but their limits of agreement were noted to be wide. This invites further development in the technology to improve their CO absolute values and improve precision
