Diagnostic and Prognostic Value of Tracheal Aspirate Procalcitonin Level in Critically Ill Pediatric Patients with Ventilated Associated Pneumonia
Authors: Ibrahim Hanan Mohammed , Ahmed Ahmed Rezk , Magdy Sondos Mohammed , Tarek Ahmed Salem Mennat Allah 
Published: November 2024

Abstract

Background
Ventilator associated pneumonia(VAP) is the second most common hospital acquired infection (HAI) after blood stream infection in the pediatric age group, accounting for about 20% of all HAIs in the pediatric intensive care units (PICUs) and has a rate of 2.9- 21.6 per 1000 ventilator days. VAP should be suspected in patients with a new or progressive pulmonary infiltrate on imaging plus supportive clinical findings of infection (e.g., fever, secretions, leukocytosis). The diagnosis is confirmed when lower respiratory tract sampling identifies pathogen.

Aim of the Work
To assess diagnostic and prognostic value of tracheal aspirate procalcitonin level in critically ill pediatric patients with VAP.

Patients and Methods
This prospective cohort study was conducted on 50 ventilated patients collected from Pediatric Intensive Care Unit, Ain Shams University Children's hospital in a period of 6 months starting from June 2023 till December 2023; they were divided into two groups VAP group and non VAP group. They were 26 females (52.0%) and 24 males (48%) with age ranged from 0.17 – 7 years and with median (IQR) of 1.75 (0.56 – 3).

Results
Regarding to our study procalcitonin (PCT) measured for 50 ventilated patietns at day 1 showed median IQR 269.85 pg/ml(183.7pg/ml–646.8pg/ml) with range 72.3pg/ml–2500pg/ml. At day 3 studeid patients divided into 2 groups VAP and non VAP group according to centers of disease control(CDC) criteria of VAP diagnosis and with comparing PCT level at day 3 between 2 groups showed statistically significant increase in the level of procalcitonin at day 3 in VAP group [574.9pg/ml(362pg/ml – 719pg/ml)] than non VAP group [280pg/ml(192.9pg/ml – 555pg/ml)] with p-value = 0.026 and the best cut off point for procalcitonin level at day 3 to differentiate between VAP and non VAP groups was found &gt; 255.4pg/ml with sensitivity of 92%, specificity of 48% and area under curve (AUC) of 68.3%. Among VAP group procalcitonin level measured at Broncho alveolar lavage (BAL) and serum at the same time and incomparing two levels there was no statitically significant difference found between level of PCT in BAL and serum with p-value 0.778. PCT as a prognostic marker it showed PCT level, significantly increase at day 3 and onset of VAP in BAL and serum in died patients than discharged patients with p-value = 0.003, 0.031 and 0.005; respectively.

Conclusion
This study underscores the significant diagnostic and prognostic value of procalcitonin levels in critically ill pediatric patients with (VAP). Procalcitonin levels, especially at day 3, demonstrated good diagnostic performance in differentiating between VAP and non-VAP cases. Additionally, procalcitonin levels in bronchoalveolar lavage (BAL) and serum at the onset of VAP emerged as highly reliable markers for confirming the presence of VAP, with excellent sensitivity and specificity. These findings highlight the potential for procalcitonin to aid in the early diagnosis and management of VAP in this vulnerable patient population, ultimately contributing to improved clinical outcomes and patient care in intensive care settings.