Systemic Inflammatory Response Index (SIRI) vs. Platelet-to-Lymphocyte Ratio (PLR) in Predicting Sepsis Outcomes in Critically Ill Children: The Role of Hemodynamics and Confounding Factors

Objective/Aims: Sepsis is still one of the main reasons infants contract illness and suffer in paediatric intensive care units (PICUs), so we need reliable biomarkers to help us quickly figure out who is at risk. This research focusses at how well the Systemic Inflammatory Response Index (SIRI) and the Platelet-to-Lymphocyte Ratio (PLR) serve to predict that which will take place for children with sepsis who are very ill. It also examines at how instability in the blood flow and other variables affect the results. Methods: Sepsis is still one of the main reasons infants contract illness and suffer in paediatric intensive care units (PICUs), so we need reliable biomarkers to help us quickly figure out who is at risk. This research focusses at how well the Systemic Inflammatory Response Index (SIRI) and the Platelet-to-Lymphocyte Ratio (PLR) serve to predict that which will take place for children with sepsis who are very ill. It also examines at how instability in the blood flow and other variables affect the results. Results: In this study, we investigated retrospectively at 110 septic children (ages 4 to 14) who were admitted to a tertiary PICU from 2023 to 2024. To find SIRI and PLR, we used full blood counts that had been performed when the patient was admitted. These were the main outcomes: mortality, organ failure (PELOD-2), and length of stay in the PICU (LOS). When we evaluated the extent to which those biomarkers was employed, we used multivariate logistic regression and ROC analyses. These analyses considered into account treatments, other health problems, and age. Participants in the group were mostly 4.2 years old (IQR: 1.5–8.7), and 42% of them had septic shock. It was easier for SIRI to prognosticate who would pass away (AUC:0.78 vs. PLR:0.65; p=0.01), especially in people whose blood flow wasn't stable (AUC:0.82). It was very likely that someone would die (aOR:2.8,95%CI:1.6–4.9), have a new organ fail (aOR:2.5,95%CI:1.5–4.2), or stay in the hospital longer (9 days vs. 5 days,p<0.001). The links between PLR and death were weaker (aOR:1.4, p=0.15), and blood transfusions had a greater effect on them (p=0.01). In people whose immune systems were not strong (SIRI AUC:0.68), neither biomarker did very well. Conclusions: Finally, SIRI is better than PLR at predicting bad outcomes in kids with sepsis, especially when their blood pressure isn't stable. Adding it to the rules for getting into the PICU might help with risk stratification, but it still needs to be tested on people whose immune systems aren't strong enough. Because PLR can be changed by other things, it is not as useful in the clinic. These results show that SIRI is a useful and simple tool for figuring out how paediatric sepsis will progress and letting doctors act quickly.