Background and Aims Inferior vena cava and Aortic measurements and indices like IVC and Aorta diameter , collapsibility index, distensibility index etc are established parameters for intravascular volume assessment in adults. Literature in pediatric patients is scanty especially in the perioperative setting. This study was planned to evaluate the inter-observer reliability of ultrasound measurements of the IVC and Aortic diameters using the sub-xiphoid trans-abdominal long axis (SXTL) view in fasting pediatric patients, both during spontaneous and controlled ventilation.

Methods After institutional ethics approval and informed consent 50 patients, aged 1 to 12 years, were assessed for intravascular volume indices during spontaneous ventilation and controlled ventilation by two blinded observers, one experienced in ultrasound and one trainee using the SXTL view.

Results The inter-observer reliability for SXTL view was assessed using intraclass correlation coefficient (ICC) and was found to be excellent to good. The ICC for the maximum IVC diameter (IVC max) during spontaneous ventilation was 0.879 (0.787-0.931), for minimum IVC diameter (IVC min) was 0.708 (0.485-0.834) and for maximum aorta diameter (Ao max) was 0.695(0.459-0.827). The ICC for IVC max during controlled ventilation was 0.866 (0.758-0.925), for IVC min was 0.851(0.735-0.915) and for Ao max was 0.866(0.765-0.924).

Conclusions There was good inter-reliability for measuring the diameter of IVC and aorta during both spontaneous and controlled ventilation, using the SXTL view. After a short training session, a trainee can reliably measure the diameter of these vessels using this view.