Sequential Shock Index as a Prognostic Marker in Children with Septic Shock- A Cohort Study

Introduction: Shock Index (SI), is a simple ratio of Heart Rate (HR) and Systolic Blood Pressure (SBP) and a good marker of haemodynamic stability than HR or SBP individually.

Aim: To assess the prognostic value of sequential SI and to compare whether higher SI at admission or worsening SI since admission predicts higher mortality in children.

Materials and Methods: The present cohort study included 50 children between 1-5 years who presented in the Paediatric emergency with shock. The HR, SBP and SI were calculated at 0 and 6 hours of admission. According to the changes in SI over time, the children were divided into four groups, Group 1 (normal SI at 0 and 6 hours), Group 2 (normal SI at 0 hours and abnormal SI at 6 hours), Group 3 (abnormal SI at 0 hours and normal SI at 6 hours), Group 4 (abnormal SI at 0 and 6 hours). They were followed to their condition at discharge and were further subdivided into two groups (survived/died). The relative risk of death was compared among the groups.

Results: Taking the first group as the reference, the relative risk of mortality was 1.442 (Group 2), 1.026 (Group 3), 2.712 (Group 4) i.e., the risk of mortality was highest in the children with worsening SI since admission. Difference in SI at 0 and 6 hours was statistically significant between survivors and non survivors (p=0.001, p<0.001, respectively). In the ROC, SI at 0 hours (0.877) had more sensitivity than SI at 6 hours (0.863).

Conclusion: The SI is a simple, non invasive, cost-effective and a quick tool to detect patients with high risk of mortality and can be used as a quick non invasive method for prompt identification and categorisation of critical illness in Emergency Department. It should be added to HR and SBP, thereby assisting in early identification of septic shock and also the need for aggressive management. Sequential SI values can have a better prognostic value than single admission SI.