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Short Communication Volume 14 Issue 4
Combating bacterial resistance in ICU-pediatric burns under vasopressor support with vancomycin–meropenem, guided by PK/PD and neutrophil-to-lymphocyte ratio
Silvia Regina Cavani Jorge Santos, Frederico Ribeiro Pires, Mauro Jorge Santos, Aline Sandre Gomides Abad, Gabriela Aparecida Ferreira, Thiago Câmara de Oliveira, Maria Severina dos Santos, Nilo José Coelho Duarte, Paschoalina Romano, Persio de Almeida Rezende Ebner, Nairo Massakazu Sumita, Débora Cristina Sanches Pinto, Edvaldo Vieira de Campos, Elson Mendes da Silva Junior, João Manoel da Silva Junior, David de Souza Gomez
Received: July 03, 2026 | Published: September 2, 2026
Citation: Santos SRCJ, Pires FR, Santos MJ, et al. Combating bacterial resistance in ICU-pediatric burns under vasopressor support with vancomycin– meropenem, guided by PK/PD and neutrophil-to-lymphocyte ratio. Pharm Pharmacol Int J. 2026;14(4):102-107. DOI: 10.15406/ppij.2026.14.00501
Abstract
Background—Study objective: Meropenem and vancomycin are widely used to treat hospital-acquired Gram negative and Gram-positive infections in septic patients with systemic inflammatory response. In pediatric ICU patients with major burns, pharmacokinetic changes may reduce antimicrobial exposure and compromise outcomes, making serum antibiotic levels and culture monitoring essential, especially when early dose adjustment is needed. This study evaluated combined vancomycin-meropenem therapy in pediatric major burns with preserved or augmented renal clearance under vasopressor support. Treatment was adjusted in real time using culture results and serum drug monitoring to reach PK/PD targets for efficacy and safety during the first ICU episode of septic shock. The neutrophilto-lymphocyte ratio (N/L-ratio), associated with mortality risk, was also used as a selected biomarker of systemic inflammatory response syndrome in septic pediatric burn patients. Methods: Twenty-one pediatric septic burn patients (2–13 years; 12M/9F) treated with vancomycin meropenem were evaluated after empiric dosing normalized to ideal body weight. Then, patients were stratified by age in Group 1 (2-7 yrs) and Group 2 (8-13yrs). Vancomycin was initially administered in Set 1 at 40–60 mg/kg/day by 1-hour infusion and, when necessary, adjusted in Set 2 to achieve an AUC ss0–24/MIC target of >400–600. Meropenem (40 mg/kg q8h, 3-hour infusion) targeted 100% f∆T>MIC. Drug Serum concentrations were routinely measured at predefined time points, pharmacokinetics was assessed using a one-compartment model, and the daily neutrophil-to-lymphocyte ratio (N/L-ratio) was applied to monitor systemic inflammation and ICU mortality risk. Drug effectiveness was assessed using antibiotic-specific PK/PD targets, negative culture results, and the microbiological profile of the isolated pathogens. The neutrophil-to-lymphocyte ratio (N/L-ratio) was also used as a supporting biomarker associated with ICU mortality risk in critically ill septic patients. Results: Septic pediatric major burn patients 21 (12M/9F) with renal function preserved or augmented were distributed by age: 2-7 yrs. (Group 1, n=11), 8-13 yrs. (Group 2, n=10). Target was attained by vancomycin up to MIC 1 mg/L against Gram-positive strains only in 62% (13/21) patients receiving an empiric dose regimen (1015mg/kg q6h, 1hr infusion (Set 1). Individualized therapy was prescribed; then, the coverage was extended up to MIC 2 mg/L strains in 71% (15/21) patients in Set 2 to avoid MDRB. Vancomycin effectiveness occurs by clinical and microbiological cure of infection. Meropenem (40 mg/kg q8h, 3-hour infusion) showed age-dependent pharmacokinetic differences but achieved cure of infections caused by Gram-negative bacteria isolated. It eradicated susceptible strains up to MIC 2 mg/L, extended coverage to MIC 4 mg/L in all patients, and covered MIC 8 mg/L occurred in 55% of Group 1 (6/11) and 50% of Group 2 (5/10), helping prevent multidrug resistance bacterial, MDRB. Conclusion: Pediatric septic burn patients receiving combined vancomycin–meropenem therapy for nosocomial infections requires frequent culture and serum drug-level monitoring to ensure PK/PD target attainment and eradication of Gram-positive and Gramnegative bacteria. No relevant between-group difference was observed in vancomycin pharmacokinetic changes, despite a twofold reduction in half-life associated with vasopressor use. In contrast, age-independent meropenem pharmacokinetic differences affected antimicrobial coverage across groups. Individualized antimicrobial coverage supported clinical and microbiological cures. The neutrophil-to-lymphocyte ratio (N/L- ratio) provided real-time assessment of systemic inflammation and helped guide decisionmaking in pediatric patients at the ICU Burn Center.
Keywords: pediatric septic burns, combined vancomycin–meropenem therapy, PK/PD- guided serum monitoring, culture-guided antimicrobial therapy, neutrophil-to-lymphocyte ratio, clinical decision-making
©2026 Santos, et al. This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work non-commercially.