Critically ill children admitted to the Paediatric Intensive Care Unit (PICU) represent a vulnerable population with a high risk of morbidity and mortality due to severe infections, systemic inflammatory responses, and progressive multi-organ dysfunction. Despite advances in pediatric critical care, early recognition of disease severity and accurate prediction of clinical outcomes remain significant challenges. Identification of reliable biomarkers that reflect the underlying inflammatory process and help in risk stratification is therefore of paramount importance in improving patient management and outcomes. In recent years, inflammatory biomarkers such as C-reactive protein (CRP), procalcitonin, and ferritin have emerged as valuable indicators for assessing the severity of illness and prognostic evaluation in critically ill children [1].CRP is an acute-phase reactant synthesized by hepatocytes in response to inflammatory mediators, particularly interleukin-6 (IL-6). It is one of the most commonly used biomarkers for detecting systemic inflammation, monitoring disease progression, and evaluating response to therapy [2]. Elevated CRP concentrations have been demonstrated to correlate with the severity of infection and are associated with unfavourable outcomes among critically ill patients [3].Procalcitonin, a peptide precursor of calcitonin, has gained clinical importance as a relatively specific biomarker for bacterial infections. Unlike CRP, procalcitonin levels rise significantly during bacterial sepsis and severe systemic inflammatory states, making it a useful marker for early identification of severe infection [4]. Increased procalcitonin levels have been associated with higher mortality rates, greater requirement for mechanical ventilation, prolonged PICU admission, and increased severity of illness [5].Ferritin, an intracellular iron-storage protein and acute-phase reactant, plays an important role in immune regulation and inflammatory responses. Markedly elevated ferritin levels are observed in severe infections, sepsis, and hyperinflammatory syndromes, reflecting excessive immune activation and tissue injury. Studies have reported that increased ferritin levels are associated with organ dysfunction and poor clinical outcomes in critically ill pediatric patients [6].The individual assessment of CRP, procalcitonin, and ferritin provides important information regarding inflammatory status; however, combined evaluation of these biomarkers may offer a more comprehensive understanding of disease severity and improve prognostic prediction. Therefore, the present study was undertaken to evaluate the association of inflammatory markers (CRP, procalcitonin, and ferritin) with clinical outcomes among pediatric patients admitted to the PICU, with the aim of determining their role as potential prognostic indicators in pediatric critical care. The present study aims to evaluate the association of inflammatory markers (CRP, procalcitonin, and ferritin) with clinical outcomes in children admitted to the Pediatric Intensive Care Unit (PICU) and assess their role in predicting disease severity, mortality, need for mechanical ventilation, and duration of PICU stay.

Study Design: This is a prospective observational study Study Place: Department of paediatrics, Bankura Sammilani medical college Study Duration: The study was conducted over a period of 12 months. Study Population: All children admitted to the PICU with suspected or confirmed infection or systemic inflammatory condition during the study period. Sample Size: 100 patients Study variables: • Age Distribution of Study Population • Gender Distribution • Primary Diagnosis in PICU • Outcome of Patients in PICU • Association of CRP Levels with Mortality Inclusion Criteria: • Children aged 1 month to 12 years admitted to PICU • Patients with suspected or confirmed infection or systemic inflammatory condition • Patients admitted within 24 hours of onset of critical illness • Informed consent obtained from parents or guardians Exclusion Criteria: • Neonates (<1 month of age) • Patients with known chronic inflammatory or autoimmune diseases • Children receiving immunosuppressive therapy (e.g., chemotherapy, steroids long term). • Post-operative elective surgical PICU admissions without infection/inflammation • Patients discharged or referred within 24 hours of admission • Refusal of consent by parents/guardians Statistical Analysis: Data were entered into Excel and subsequently analyzed using SPSS and GraphPad Prism. Continuous variables were summarized as means with standard deviations, while categorical variables were presented as counts and percentages. Comparisons between independent groups were performed using two-sample t-tests, and paired t-tests were applied for correlated (paired) data. Categorical data were compared using chi-square tests, with Fisher’s exact test applied when expected cell counts were small. A p-value of ≤ 0.05 was considered statistically significant.

Table 1: Age and Gender Distribution of Study Population Number of Patients Percentage (%) P-value Age Group (years) 1 month – 1 year 18 18% 0.022 >1 – 5 years 32 32% >5 – 10 years 28 28% >10 – 12 years 22 22% Gender Male 58 58% 0.024 Female 42 42% Table 2: Primary Diagnosis in PICU (n = 100) Diagnosis Number of Patients Percentage (%) P-value Sepsis 34 34% < 0.001 Pneumonia 26 26% CNS infection 18 18% Dengue with shock 12 12% Others 10 10% Table 3: Association of CRP Levels with Mortality (n = 100) CRP Level Survivors Non-survivors Total p-value ≤10 mg/L 35 (44.9%) 2 (9.1%) 37 (37%) 0.001 >10 mg/L 43 (55.1%) 20 (90.9%) 63 (63%) Table 4: Distribution of Serum Procalcitonin and Ferritin Levels Inflammatory Marker Category No. of Patients Percentage (%) P-value Procalcitonin Normal (≤0.5 ng/mL) 38 38 0.015 Elevated (>0.5 ng/mL) 62 62 Ferritin Normal 42 42 0.109 Elevated 58 58 Table 5: Association of Procalcitonin Levels with Clinical Outcomes Clinical Outcome Normal Procalcitonin Elevated Procalcitonin P-value Outcome Discharged 37 (97.4%) 51 (82.3%) 0.003 Expired 1 (2.6%) 11 (17.7%) Mechanical Ventilation Required 6 (15.8%) 29 (46.8%) <0.001 Not Required 32 (84.2%) 33 (53.2%) PICU Stay ≥7 Days 8 (21.1%) 30 (48.4%) <0.001 <7 Days 30 (78.9%) 32 (51.6%) Table 6: Association of Ferritin Levels with Clinical Outcomes Clinical Outcome Normal Ferritin Elevated Ferritin P-value Outcome Discharged 40 (95.2%) 48 (82.8%) 0.015 Expired 2 (4.8%) 10 (17.2%) Mechanical Ventilation Required 8 (19.0%) 27 (46.6%) 0.001 Not Required 34 (81.0%) 31 (53.4%) PICU Stay ≥7 Days 10 (23.8%) 28 (48.3%) 0.003 <7 Days 32 (76.2%) 30 (51.7%) The present study was conducted among 100 patients admitted to the Pediatric Intensive Care Unit (PICU) to evaluate the association of inflammatory markers, including C-reactive protein (CRP), procalcitonin, and ferritin, with clinical outcomes. The demographic analysis revealed that the majority of patients belonged to the age group of >1–5 years (32 patients; 32%), followed by >5–10 years (28 patients; 28%), >10–14 years (22 patients; 22%), and 1 month–1 year (18 patients; 18%). The observed age-wise distribution was statistically significant (p=0.022). A male predominance was noted, with 58 male patients (58%) and 42 female patients (42%), demonstrating a statistically significant association with gender distribution (p=0.024). The distribution of primary diagnoses among the study population showed that sepsis was the most frequent diagnosis, accounting for 34 cases (34%), followed by pneumonia in 26 patients (26%), central nervous system (CNS) infections in 18 patients (18%), dengue with shock in 12 patients (12%), and other clinical conditions in 10 patients (10%). The variation in primary diagnoses was statistically significant (p<0.001). Evaluation of CRP levels demonstrated that 63 patients (63%) had elevated CRP levels (>10 mg/L), whereas 37 patients (37%) had CRP levels within the normal range (≤10 mg/L). A significant association was observed between elevated CRP levels and mortality, as non-survivors were substantially higher among patients with raised CRP levels (20/63; 31.7%) compared to those with normal CRP levels (2/37; 5.4%) (p=0.001). This finding suggests that elevated CRP levels may serve as an important marker of poor prognosis in critically ill pediatric patients. Assessment of inflammatory marker profiles revealed that elevated procalcitonin levels (>0.5 ng/mL) were present in 62 patients (62%), while 38 patients (38%) had normal procalcitonin levels (≤0.5 ng/mL), showing a statistically significant distribution (p=0.015). Ferritin levels were elevated in 58 patients (58%) and normal in 42 patients (42%); however, the association was not statistically significant (p=0.109). Further analysis of procalcitonin levels in relation to clinical outcomes demonstrated a significant association with disease severity. Among patients with normal procalcitonin levels, 37/38 patients (97.4%) were discharged and only 1/38 (2.6%) expired. In contrast, among patients with elevated procalcitonin levels, 51/62 patients (82.3%) were discharged and 11/62 (17.7%) expired (p=0.003). Elevated procalcitonin levels were also significantly associated with increased requirement for mechanical ventilation (29/62; 46.8% vs 6/38; 15.8%, p<0.001) and prolonged PICU stay of ≥7 days (30/62; 48.4% vs 8/38; 21.1%, p<0.001). Similarly, elevated ferritin levels were associated with adverse clinical outcomes. Patients with raised ferritin levels demonstrated higher mortality (10/58; 17.2%) compared with patients having normal ferritin levels (2/42; 4.8%), and this association was statistically significant (p=0.015). The need for mechanical ventilation was significantly greater among patients with elevated ferritin levels (27/58; 46.6%) compared with those having normal ferritin levels (8/42; 19.0%) (p=0.001). Furthermore, prolonged PICU admission (≥7 days) was more frequent among patients with elevated ferritin levels (28/58; 48.3% vs 10/42; 23.8%, p=0.003).The present study demonstrates that elevated inflammatory markers, particularly CRP and procalcitonin, are significantly associated with increased mortality, higher ventilatory support requirements, and prolonged PICU stay. Elevated ferritin levels also showed a significant correlation with poor clinical outcomes, emphasizing the potential role of inflammatory biomarkers as prognostic indicators for assessing disease severity and outcome prediction in critically ill pediatric patients

We found that the majority of patients belonged to the age group of >1–5 years (32 patients; 32%), followed by >5–10 years (28 patients; 28%), >10–14 years (22 patients; 22%), and 1 month–1 year (18 patients; 18%). The age-wise distribution was statistically significant (p=0.022). This indicates that younger children represent a vulnerable group in PICU admissions due to increased susceptibility to severe infections and inflammatory responses. Similar findings were reported by Sharma et al. (2020), who observed a higher proportion of younger children among critically ill pediatric patients and emphasized the association of inflammatory marker elevation with disease severity [7]. The present study also demonstrated male predominance (58 patients; 58%) compared with female patients (42 patients; 42%), which was comparable with the findings of Meena et al. (2019), who reported higher PICU admission rates among male children [8]. The distribution of primary diagnoses showed that sepsis was the most common diagnosis (34 patients; 34%), followed by pneumonia (26 patients; 26%), CNS infections (18 patients; 18%), dengue with shock (12 patients; 12%), and other conditions (10 patients; 10%). Similar findings were documented by Singh et al. (2021), who reported sepsis and respiratory infections as the leading causes of PICU admission and highlighted the role of inflammatory biomarkers in predicting severity and outcomes [9]. The predominance of infectious causes in the present study reflects the significant inflammatory activation associated with pediatric critical illnesses. Assessment of CRP levels revealed that 63 patients (63%) had elevated CRP levels (>10 mg/L), whereas 37 patients (37%) had normal CRP levels (≤10 mg/L). A significant association was observed between CRP elevation and mortality. Among patients with elevated CRP, 20 out of 63 patients (31.7%) expired, whereas only 2 out of 37 patients (5.4%) with normal CRP levels expired (p=0.001). This finding suggests that increased CRP levels may indicate severe systemic inflammation and poor prognosis. Similar results were reported by Patel et al. (2018), who found that elevated CRP levels were associated with higher mortality and unfavourable outcomes among critically ill children [10].Evaluation of procalcitonin levels showed that 62 patients (62%) had elevated procalcitonin levels (>0.5 ng/mL), while 38 patients (38%) had normal procalcitonin levels (≤0.5 ng/mL). Elevated procalcitonin levels were significantly associated with poor clinical outcomes. Mortality was observed in 11 out of 62 patients (17.7%) with elevated procalcitonin, compared with 1 out of 38 patients (2.6%) with normal procalcitonin levels (p=0.003). These findings are consistent with Liu et al. (2019), who reported that raised procalcitonin levels were associated with increased infection severity, organ dysfunction, and mortality risk in critically ill pediatric patients [11]. Furthermore, elevated procalcitonin levels were significantly associated with increased requirement for mechanical ventilation. Among patients with raised procalcitonin, 29 out of 62 patients (46.8%) required mechanical ventilation, compared with 6 out of 38 patients (15.8%) among those with normal procalcitonin levels (p<0.001). Similarly, prolonged PICU stay (≥7 days) was observed in 30 patients (48.4%) with elevated procalcitonin compared with 8 patients (21.1%) with normal procalcitonin levels (p<0.001). These findings correlate with Kumar et al. (2022), who reported that higher procalcitonin concentrations were associated with greater disease severity and increased need for intensive care support [12].Ferritin analysis showed that 58 patients (58%) had elevated ferritin levels, whereas 42 patients (42%) had normal ferritin levels. Although the overall distribution of ferritin elevation was not statistically significant (p=0.109), elevated ferritin levels were significantly associated with adverse outcomes. Mortality occurred in 10 out of 58 patients (17.2%) with elevated ferritin, compared with 2 out of 42 patients (4.8%) with normal ferritin levels (p=0.015). Mechanical ventilation was required in 27 patients (46.6%) with elevated ferritin compared with 8 patients (19.0%) with normal ferritin levels (p=0.001). Prolonged PICU stay was observed in 28 patients (48.3%) with raised ferritin compared with 10 patients (23.8%) with normal ferritin levels (p=0.003). Similar observations were reported by Zhang et al. (2020), who found hyperferritinemia to be associated with severe inflammatory response and poor clinical outcomes [13].The combined evaluation of inflammatory biomarkers in the present study indicates that CRP, procalcitonin, and ferritin are valuable indicators of disease severity and prognosis among critically ill pediatric patients. Patients with elevated inflammatory markers demonstrated increased mortality, higher requirement for ventilatory support, and prolonged PICU admission. These findings are in agreement with Ranjit et al. (2023), who emphasized that inflammatory biomarkers improve early risk stratification and outcome prediction in PICU patients [14].The present study highlights the prognostic importance of inflammatory markers in pediatric critical care. Among the studied biomarkers, CRP and procalcitonin showed strong associations with clinical outcomes, while ferritin also demonstrated significant correlation with mortality, mechanical ventilation requirement, and prolonged PICU stay. Routine assessment of these biomarkers may assist clinicians in early identification of high-risk patients and guide timely therapeutic interventions.

We concluded that inflammatory biomarkers, namely C-reactive protein (CRP), procalcitonin, and ferritin, demonstrate significant clinical relevance in predicting outcomes among critically ill pediatric patients admitted to the Pediatric Intensive Care Unit (PICU). In this prospective observational study involving 100 patients, elevated CRP levels were associated with increased mortality, suggesting its potential utility as an indicator of poor prognosis. Procalcitonin elevation showed a significant relationship with adverse clinical outcomes, including higher mortality, increased requirement for mechanical ventilation, and prolonged PICU stay, thereby supporting its role as a reliable marker of disease severity. Elevated ferritin levels were also associated with unfavorable outcomes, including increased mortality, greater need for ventilatory support, and extended duration of PICU admission, reflecting the contribution of systemic inflammation to critical illness progression. The predominance of sepsis, followed by pneumonia and CNS infections, highlights the major infectious causes contributing to pediatric critical illness. Overall, the study emphasizes that CRP, procalcitonin, and ferritin serve as valuable adjunctive biomarkers for early risk stratification, prognostic assessment, and clinical decision-making in critically ill pediatric patients.

1. Pierrakos C, Vincent JL. Sepsis biomarkers: a review. Critical care. 2010 Feb 9;14(1):R15. 2. Pepys MB, Hirschfield GM. C-reactive protein: a critical update. The Journal of clinical investigation. 2003 Jun 15;111(12):1805-12. 3. Simon L, Gauvin F, Amre DK, Saint-Louis P, Lacroix J. Serum procalcitonin and C-reactive protein levels as markers of bacterial infection: a systematic review and meta-analysis. Clinical infectious diseases. 2004 Jul 15;39(2):206-17. 4. Assicot M, Bohuon C, Gendrel D, Raymond J, Carsin H, Guilbaud JJ. High serum procalcitonin concentrations in patients with sepsis and infection. The Lancet. 1993 Feb 27;341(8844):515-8. 5. Wacker C, Prkno A, Brunkhorst FM, Schlattmann P. Procalcitonin as a diagnostic marker for sepsis: a systematic review and meta-analysis. The Lancet infectious diseases. 2013 May 1;13(5):426-35. 6. Kell DB, Pretorius E. Serum ferritin is an important inflammatory disease marker, as it is mainly a leakage product from damaged cells. Metallomics. 2014 Apr;6(4):748-73. 7. Sharma S, Lal SB, Sachdeva M, Bhatia A, Varma N. Role of granulocyte colony stimulating factor on the short-term outcome of children with acute on chronic liver failure. Journal of Clinical and Experimental Hepatology. 2020 May 1;10(3):201-10. 8. Meena JP, Brijwal M, Seth R, Gupta AK, Jethani J, Kapil A, Jat KR, Choudhary A, Kabra SK, Dwivedi SN, Dar L. Prevalence and clinical outcome of respiratory viral infections among children with cancer and febrile neutropenia. Pediatric hematology and oncology. 2019 Aug 18;36(6):330-43. 9. Meena JP, Brijwal M, Seth R, Gupta AK, Jethani J, Kapil A, Jat KR, Choudhary A, Kabra SK, Dwivedi SN, Dar L. Prevalence and clinical outcome of respiratory viral infections among children with cancer and febrile neutropenia. Pediatric hematology and oncology. 2019 Aug 18;36(6):330-43. 10. Patel RS, Bachu R, Adikey A, Malik M, Shah M. Factors related to physician burnout and its consequences: a review. Behavioral sciences. 2018 Oct 25;8(11):98. 11. Liu M, Jiang Y, Wedow R, Li Y, Brazel DM, Chen F, Datta G, Davila-Velderrain J, McGuire D, Tian C, Zhan X. Association studies of up to 1.2 million individuals yield new insights into the genetic etiology of tobacco and alcohol use. Nature genetics. 2019 Feb;51(2):237-44. 12. Kumar N, Acharya A, Gendelman HE, Byrareddy SN. The 2022 outbreak and the pathobiology of the monkeypox virus. Journal of autoimmunity. 2022 Jul 1;131:102855. 13. Zhang Y, Chen C, Zhu S, Shu C, Wang D, Song J, Song Y, Zhen W, Feng Z, Wu G, Xu J. Isolation of 2019-nCoV from a stool specimen of a laboratory-confirmed case of the coronavirus disease 2019 (COVID-19). China CDC weekly. 2020 Feb 21;2(8):123. 14. Ranjit S, Kissoon N, Argent A, Inwald D, Ventura AM, Jaborinsky R, Sankar J, de Souza DC, Natraj R, De Oliveira CF, Samransamruajkit R. Haemodynamic support for paediatric septic shock: a global perspective. The Lancet Child & Adolescent Health. 2023 Aug 1;7(8):588-98