Pattern and Outcome of Lower Respiratory Tract Infections in Pediatric Critically Ill Patients in Intensive Care Unit during Winter Season 2022-23
Authors: Ibrahim Hanan Mohammed , Ahmed El Shawarby Hedaya Tallah , Hassan Samar Ahmed , Magdy Sondos Mohammed 
Published: November 2024

Abstract

Background
Lower respiratory tract infection (LRTIs) are the worldwide leading cause of morbidity and mortality among children under the age of five years. However, epidemiological data in the pediatric population are poor.

Objective
This study aims to describe the pattern of LRTIs in critically ill patients admitted to the PICU of Ain Shams university hospital between October 2022 to March 2023 to shed the light on causative organisms, ventilatory modes used, length of stay and outcome.

Methods
A retrospective descriptive study including all patients admitted to PICU with LRTIs between October 2022 and March 2023. Patients were excluded from this study if they had a definite history (from their parents) of a chronic lung disease; as bronchial asthma, bronchiectasis, etc.), or if they had a frank diagnosis of such disease clearly stated in their medical files prior to PICU admission. All data were collected from the official PICU files of Ain Shams University hospital.

Results
The study comprised 192 patients divided into: an infant group below 2 years representing 156 (81.3%) patients, a preschool group between 2-5 years representing 24 (12.5%) patients and a school group between 5-14 years representing 12(6.3%) patients. 62% of patients were males with a median(IQR) age 0.33 (0.166-1) years. The median (IQR) weights was 5.75 (4.1-9.5) Kgs. 93.2% of cases were diagnosed as pneumonia and 6.8% bronchiolitis. Viral infections constituted 64.1% of cases, RSV (27%), rhinovirus (19.8%), enterovirus (14.6%) and adenovirus (9.9%). Viral infections prevailed in the infant group. Bacterial infections constituted (13.5%) of cases. Klebseilla pneumoniae first with (9.9%), then pseudomonas aeruginosa (3.6%) and staphylococcus aureus (3.4%). The rest of cases (22.4%) were mixed infections. 92.7% of our patients were put initially on non-invasive (NIV) mode, 12.4% of whom reverted to invasive modes. Factors contributing to this inversion were; low initial SO2, hypercapnia, associated comorbidities, hypoalbuminemia and lymphopenia. The length of stay in the PICU was less than 2 weeks in 86.6% of cases with a median (IQR) 7(5-10) days. 13.5% of patients exceeding 2 weeks of stay were those with bacterial or mixed infections and those suffering from comorbidities. 157 (81.8%) of patients were survivors. Factors contributing to poor outcome were essentially the same factors related to the use of invasive ventilation as well as to the prolonged stay in PICU.

Conclusion
LRTI of viral origin (especially RSV) is predominant in infants below 2 years of age during the winter season with a relatively more benign course and a better outcome. Bacterial infections, on the other hand, tend to affect older children (preschool age) with more aggressive course and poorer outcome. Klebsiella pneumoniae is a bacterium which causes serious nosocomial LRTI with poor outcome and bears no relation to seasonal variation. Previous PICU and NICU admissions and the presence of associating comorbidities especially cardiac, neurological and genetic (Down syndrome) tend to prolong the PICU stay and worsen the outcome.