The epidemiology of critical respiratory diseases in ex-premature infants in Vietnam: A prospective single-center study

Introduction:This study aimed to describe the epidemiology and etiologies of criticalrespiratory diseases of ex-premature infants (EPIs) admitted to the Pediatric Inten-sive Care unit (PICU).Methods:Infants <= 2 years old with acute respiratory illnesses admitted to PICU ofVietnam National Children's Hospital from November 2019 to April 2021 wereenrolled and followed up to hospital discharge. We compared respiratory pathogens,outcomes, and PICU resources utilized between EPIs and term infants. Among EPIs,we described clinical characteristics and evaluated the association between associ-ated factors and mortality.Results:Among 1183 patients, aged <= 2 years were admitted for critical respiratoryillnesses, 202 (17.1%) were EPIs. Respiratory viruses were detected in 53.5% and38.2% among EPIs and term infants, respectively. Compared to term infants, a higherproportion of EPIs required mechanical ventilation (MV) (85.6 vs. 66.5%,p< .005)and vasopressor support (37.6 vs. 10.7%%,p< .005). EPIs had a higher median PICUlength of stay (11.0 [IQR: 7; 22] vs. 6.0 days [IQR: 3; 11],p= .09), hospital length ofstay (21.5 [IQR: 13; 40] vs. 10.0 days [IQR: 5; 18],p< .005) and case fatality rate(31.3% vs. 22.6%) compared to term infants. Among EPIs, PIM-3 score (adjustedodds ratio [aOR]: 1.51; 95% confidence interval [CI]: 1.30-1.75) and PELOD-2 scoreat admission (aOR: 1.41; 95% CI: 1.08-1.85) were associated with mortality.Conclusions:EPIs with critical respiratory illnesses constituted a significant popu-lation in the PICU, required more PICU support, and had worse clinical outcomescompared to term infants.