Early identification of pediatric trauma patients at high risk of mortality remains challenging despite advances in critical care management. Systemic inflammatory response and subsequent organ dysfunction play a central role in trauma-related mortality. Recently, the lactate/albumin ratio (LAR) and inflammatory biomarkers such as the neutrophil-to-lymphocyte ratio (NLR) have emerged as potential prognostic indicators; however, their independent predictive value in pediatric trauma remains incompletely defined. In this retrospective cohort study, 272 pediatric trauma patients admitted to a tertiary pediatric intensive care unit (PICU) were screened. After excluding 28 patients who died within the first 24 h and 34 patients with incomplete laboratory data, 210 patients were included in the final analysis. Demographic, clinical, and laboratory parameters were collected at admission. The primary outcome was in-hospital mortality. Receiver operating characteristic (ROC) curve analysis and multivariable logistic regression were performed to evaluate independent predictors of mortality. Among 210 patients, 27 (12.9%) died during PICU stay. Non-survivors had significantly higher PRISM III scores and prolonged mechanical ventilation duration. LAR demonstrated the highest discriminatory performance for mortality (AUC 0.918, 95% CI: 0.839–0.978), followed by NLR (AUC 0.900) and PRISM III score (AUC 0.884). In multivariable analysis, LAR emerged as a prominent independent predictor of mortality (OR 12.22, 95% CI: 3.08–48.49, p < 0.001), while NLR and PRISM III score remained independently associated with adverse outcomes. Conclusion : The lactate/albumin ratio was independently associated with in-hospital mortality and improved risk discrimination when added to PRISM III in this selected cohort of pediatric trauma patients. As a simple and readily available biomarker, LAR may complement established severity scoring systems and support early risk stratification, although external validation is required before clinical application. What is Known: • Serum lactate and inflammatory indices such as the neutrophil-to-lymphocyte ratio are associated with poor outcomes in pediatric trauma, but their independent prognostic value is incompletely defined .• Established severity scores like PRISM III predict mortality but may not fully capture the combined effects of tissue hypoperfusion and inflammation . What is New: • The lactate/albumin ratio independently predicted in-hospital mortality and showed the highest discrimination (AUC 0.918) among tested markers in PICU-admitted pediatric trauma patients .• Adding the lactate/albumin ratio to PRISM III improved risk discrimination, supporting its role as a simple adjunct forearly stratification pending external validation .

Background/Objectives: Early mortality after pediatric liver transplantation remains a clinical challenge, yet few studies have specifically addressed 30-day outcomes. Conventional pretransplant scores such as the age-appropriate MELD/PELD score were not designed for post-transplant risk prediction. We aimed to evaluate whether dynamic postoperative biomarker trajectories and novel composite ratios can identify high-risk patients. Methods: This single-center retrospective cohort study included 140 consecutive pediatric patients (30 days, n = 129). PRISM-III, PELOD-2, and age-appropriate MELD/PELD scores were evaluated. Serial laboratory parameters were collected at pretransplant and at 0, 24, and 72 h. Delta (Δ) values and composite ratios—including lactate clearance, lactate-to-albumin ratio (LAR), INR×lactate product, platelet ratio, and fibrinogen/INR—were calculated. Penalized logistic regression (Firth method) was used for multivariate analysis. Internal validation was performed using bootstrap resampling (1000 iterations) and leave-one-out cross-validation (LOO-CV). Because two of the three components of the multivariable model (ΔINR, ΔALT) were derived from 72-h values, the model is best understood as a 72-h landmark risk model rather than as an immediate post-transplant early-warning tool. Results: The 30-day mortality rate was 7.9% (11/140), with central nervous system complications as the leading cause (36.4%). PRISM-III demonstrated excellent discrimination (AUROC 0.957; cut-off ≥ 14); the age-appropriate MELD/PELD score, a pretransplant tool not designed for post-transplant prediction, showed near-chance performance (AUROC 0.513; p = 0.576). A distinctive biomarker crossover pattern was observed: non-survivors had paradoxically lower pretransplant INR, ALT, and LAR values, but trajectories diverged sharply by 24 h. The INR×lactate product achieved an AUROC of 0.981 at 72 h. LAR at 24 h achieved 0.909, and lactate clearance at 0 → 72 h achieved 0.783. Postoperative hypernatremia emerged as a strong predictor (AUROC 0.884). In multivariate analysis, PRISM-III (OR 4.00), ΔINR (OR 3.28), and ΔALT (OR 3.46) were independent predictors (apparent AUROC 0.989). Internal validation confirmed model stability: bootstrap-corrected AUROC was 0.978; LOO-CV AUROC was 0.957 (sensitivity 90.9%, specificity 96.9%). Conclusions: Dynamic postoperative factors—rather than pretransplant disease severity—appeared more strongly associated with 30-day mortality after pediatric liver transplantation in this single-center exploratory analysis. The INR×lactate product, a novel two-variable composite, showed very high apparent discrimination (AUROC 0.981) and is proposed as a hypothesis-generating candidate marker requiring prospective external validation before any clinical use. The combined PRISM-III + ΔINR + ΔALT model (best understood as a 72-h landmark risk model, since two of its three components are defined at 72 h postoperatively) demonstrated robust internal validation performance (LOO-CV AUROC 0.957); however, given the small number of events (n = 11) and the absence of external validation, the model should be regarded as exploratory.

Background/Objectives: High-flow nasal cannula (HFNC) is increasingly used after non-invasive ventilation (NIV) for post-extubation respiratory support in children, but evidence to guide the NIV-to-HFNC step-down decision is limited and the decision itself is heterogeneous across centers. In a hypothesis-generating analysis, we aimed to describe transition failure and explore bedside variables associated with it in a physician-selected cohort of pediatric patients stepped down from NIV to HFNC. Methods: This single-center retrospective study included 104 consecutive children (1 month–18 years) extubated, supported with continuous NIV, and stepped down to HFNC. Transition failure was defined as reintubation or re-escalation to NIV within 48 h. Step-down eligibility followed five predefined minimum criteria (Glasgow Coma Scale ≥ 13, FiO₂ ≤ 50%, SpO₂ ≥ 90%, hemodynamic stability, and absence of acute hypercapnia); re-escalation and reintubation followed clinical criteria routinely applied in our unit, with the precise timing of each decision left to the attending team. A prespecified exploratory multivariable logistic regression model included the ROX index at transition, the duration of NIV, and the PRISM-III score. Internal validity was assessed by bootstrap optimism-correction, five-fold cross-validation, and leave-one-out cross-validation, with a calibration plot. Results: Transition failure occurred in 24 patients (23.1%), with 79.2% within the first 24 h. The ROX index at transition showed the highest univariate discrimination (AUC 0.960, 95% CI 0.916–0.993; cut-off ≤6.0, sensitivity 83.3%, specificity 96.2%). In the exploratory multivariable model, a lower ROX index (adjusted OR 0.10, 95% CI 0.02–0.38; p < 0.001) and a longer NIV duration (adjusted OR 1.12 per hour, 95% CI 1.03–1.23; p = 0.012) were associated with transition failure; NIV duration likely behaves as a marker of unresolved respiratory pathology rather than a causal risk factor. PICU length of stay, pneumonia, and 28-day mortality were higher in the failure group. Conclusions: A transition-moment ROX index ≤ 6.0 and a longer preceding NIV duration were associated with higher risk of step-down failure. These findings are strictly hypothesis-generating, subject to confounding by indication and model optimism, and should not be translated into clinical thresholds before prospective multicenter external validation with pre-specified de-escalation and escalation criteria.

Amaç: Konvülsif status epileptikus (SE), çocukluk çağında yaşamı tehdit eden bir nörolojik acildir ve prognozu belirleyen faktörlerin erken dönemde tanımlanması önemlidir. Bu çalışmada, pediatrik yoğun bakım ünitesine kabul edilen konvülsif SE olgularında klinik özellikler ve prognostik faktörler, özellikle serum laktat düzeyleri açısından değerlendirilmiştir.Gereç ve Yöntemler: Bu retrospektif, tek merkezli çalışmaya, 2024–2025 yılları arasında üçüncü basamak pediatrik yoğun bakım ünitesine konvülsif SE tanısıyla yatırılan 2 ay–18 yaş arası hastalar dahil edilmiştir. Hastalar SE, refrakter SE (RSE) ve süper-refrakter SE (SRSE) olarak sınıflandırılmıştır. Demografik, klinik ve laboratuvar verileri analiz edilmiş; başvuru ve 6. saat serum laktat düzeyleri ile laktat klirensi değerlendirilmiştir. Lojistik regresyon ve ROC analizleri uygulanmıştır.Bulgular: Toplam 190 hastanın %20’sinde RSE ve %7,9’unda SRSE gelişmiştir. Mortalite oranı %7,9, yeni nörolojik defisit oranı %18,9’dur. En yüksek mortalite santral sinir sistemi enfeksiyonlarında (%30,4) gözlenmiştir. Refrakter olgularda yoğun bakımda kalış süresi daha uzundur (p