Perfusion index as a non-invasive predictor of mortality in the pediatric ICU: a prospective observational study

Abstract

Background & objective: This study aimed to determine the accuracy of the perfusion index (PI) as a predictor of mortality in critically ill pediatric patients.

Methodology: A prospective observational study was conducted from September 2023 to February 2024 in the Pediatric Intensive Care Unit (PICU) of the Sindh Institute of Child Health and Neonatology (SICHN). All patients aged 1 month to 15 years who did not undergo any interventions were included. Perfusion index (PI) values were measured at 0, 1, and 6 hours using a Masimo Radical-7 pulse oximeter, along with documentation of hemodynamic parameters.

Results: Among 296 critically ill children (median age: 9 months), 84 (28.4%) died. A total of 888 PI readings were recorded. At 0 hours, 47% had a PI < 1.0, which was significantly associated with mortality (p < 0.001). Perfusion Index (PI) at 0 hours showed 76.2% sensitivity and 64.6% specificity; at 6 hours, specificity rose to 87.3%. ROC analysis showed AUCs of 0.75 and 0.74 at 0 and 6 hours, respectively. Persistently low PI was linked with higher mortality.

Conclusions: A persistently low perfusion index (PI) is associated with increased mortality in critically ill pediatric patients, supporting it as a non-invasive early risk stratification and triage tool in the PICU.

Abbreviations: PI: Perfusion index, PICU: Pediatric Intensive Care Unit, SI: shock index, ScvO₂: central venous oxygen saturation, SET: Signal Extraction Technology

Keywords: Perfusion index; Pediatric ICU; Pulse Oximetry; Mortality; Infant; Child

Citation: Saleem K, Panhwer T, Khalid M, Khan S, Haque AU. Perfusion index as a non-invasive predictor of mortality in the pediatric ICU: a prospective observational study. Anaesth. pain intensive care 2025;29(8):912-918. DOI: 10.35975/apic.v29i8.3018.

Received: July 18, 2025; Revised: August 05, 2025; Accepted: August 06, 2025