[Pediatric Index Mortality 3 (PIM3) Score as a predictor of mortality in pediatric critical care unit located at high...

Area of Science:

• Pediatric critical care medicine
• Clinical risk stratification
• High-altitude physiology

Background:

• The Pediatric Index of Mortality 3 (PIM3) is a validated tool for estimating mortality risk in pediatric intensive care units (PICUs).
• Its performance in high-altitude environments (above 2,500 meters) requires specific validation.
• Assessing novel biomarkers to enhance predictive accuracy is crucial for pediatric critical care outcomes.

Purpose of the Study:

• To validate the PIM3 scale in a pediatric population admitted to PICUs situated at altitudes exceeding 2,500 meters above sea level.
• To evaluate the impact of serum lactate and the oxygen saturation/fraction of inspired oxygen (SpO2/FiO2) index on the PIM3 scale's predictive mortality ability.

Main Methods:

• A prospective, multicenter study involving 10 PICUs in Colombia.
• Data collection included variables for PIM3 calculation, serum lactate, and the SpO2/FiO2 index.
• Validation of discrimination using the area under the ROC curve and calibration via the Hosmer-Lemeshow goodness-of-fit test.

Main Results:

• The study included 2,803 admissions with an overall mortality rate of 4.8%.
• The PIM3 scale demonstrated adequate discrimination (ROC 0.84) but poor calibration (p < 0.001) in this high-altitude population.
• Incorporating lactate and SpO2/FiO2 significantly improved calibration (p = 0.75) while maintaining high discrimination (ROC 0.86).

Conclusions:

• The PIM3 scale offers adequate discrimination but lacks sufficient calibration for pediatric patients in PICUs at high altitudes (>2,500 m).
• Serum lactate and the SpO2/FiO2 index enhance the PIM3 scale's predictive accuracy in this specific population.
• These findings support the use of additional biomarkers to refine mortality risk assessment in high-altitude pediatric critical care.