Characteristics of hemodynamic parameters after fluid resuscitation and vasoactive drugs administration in pediatric shock: A prospective observational study.

Background: Prior studies have shown that septic shock survivors had a normal cardiac index (CI) and systemic vascular resistance index (SVRI). However, this feature seems to be questionable in other-caused shock, since several factors are associated with the hemodynamic profile. This study aims to describe hemodynamic profiles (preload, inotropy, afterload, stroke volume, and cardiac output) after fluid resuscitation and vasoactive therapy in children with shock.

Methods: Children aged 1 month to 18 years old with shock conditions were included in this study. Fluid resuscitation was administered following the American College of Critical Care Medicine (ACCM) protocol. Hemodynamic profiles were assessed at 1 and 6 h from the start of fluid resuscitation. Grouping of the subjects was determined by the USCOM examination in 1st hour until the end of the study and we divided into 3 groups.

Results: At 1 h, group 1 (low CI) was 14% (CI:2.5[1.2-3.2]L/min/m), group 2 (normal CI) was 66% (CI:4.2[3.4-5.8]L/min/m), and group 3 (high CI) was 20% (CI:7.1[6.1-9.4]L/min/m). SVRI was higher in groups 1 and 2 compared to group 3 (p < 0.05). Group 1 and 2 revealed fluid-refractory shock (SVV:25[12-34]% and 29(13-58)%, respectively), lower Smith-Madigan Inotropy Index (SMII) and higher Potential to Kinetic Ratio (PKR) compared to group 3 (p < 0.05). Group 3 revealed fluid-responsive shock (Stroke Volume Variation (SVV):32[18-158]%), higher SMII and lower PKR. At 6th hour, CI in all groups were normal (group 1:3.5[1.2-7.5]; group 2:4.0[1.7-6.1]; group 3:6.0[3.1-6.2]). However, 71.4% and 54.5% of subjects in groups 1 and 2, respectively, still revealed low inotropy. Group 3 revealed a significant increase in SVRI and PKR (p < 0.01).

Conclusions: Most pediatric shock patients were hypodynamic. Even when the CI was normal, the preload, inotropy, and afterload may still be abnormal. It represented the inotropy as a key to hemodynamic.