title: Premorbid factors and outcome associated with respiratory virus infections in a pediatric intensive care unit.
abstract: OBJECTIVE
  The purpose of this study was to report the clinical features and outcome of all children with a laboratory proven diagnosis of respiratory virus infection admitted to a university Pediatric Intensive Care Unit (PICU).
  
  
  METHODS
  Retrospective study between January 2003 and April 2007 was carried out in the PICU. Every child with a laboratory-confirmed viral infection was included.
  
  
  RESULTS
  54 viruses were identified in 49 children (27 M, 22 F) over a 52-month period. The three respiratory virus species, respiratory syncytial virus (RSV) (n = 17), influenza (n = 13) and parainfluenza (n = 12), accounted for 86% of these 49 cases. PICU admissions due to influenza A (n = 10) were more common than influenza B (n = 3), whereas parainfluenza type 3 (n = 7) was the commonest subtype of parainfluenza infection. Comparing these three common viruses, the mean age of children admitted with RSV was lower than with influenza or parainfluenza (1.2 years vs. 5.6 years vs. 2.4 years, P = 0.003). Pre-existing conditions such as prematurity and chronic lung disease were only present in children with RSV infection. These respiratory viruses caused both upper (croup) and lower respiratory tract diseases (bronchiolitis, pneumonia). Extrapulmonary presentations were less prevalent and included encephalitis, seizures, cardiac arrest, coexisting diabetes ketoacidosis and acute lymphoblastic leukemia. One patient with RSV and another with influenza A died during their PICU stay. Nearly half of these patients required ventilatory support or received systemic corticosteroids, and 88% received initial broad spectrum antibiotic coverage. Approximately one in five of them had nebulised adrenaline, airway endoscopies or bacterial co-infections. Adenovirus was isolated in four patients and two (both with adenovirus type 3) died during the PICU stay.
  
  
  CONCLUSIONS
  In PICU, respiratory viral infections were associated with significant morbidity and life-threatening conditions.
authors.affiliation: Department of Pediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China. ehon@hotmail.com
authors.forename: Kam Lun
authors.initials: KL
authors.lastname: Hon
authors.forename: Erica
authors.initials: E
authors.lastname: Leung
authors.forename: Erica
authors.initials: E
authors.lastname: Hung
authors.forename: Julian
authors.initials: J
authors.lastname: Tang
authors.forename: Chung Mo
authors.initials: CM
authors.lastname: Chow
authors.forename: Ting Fan
authors.initials: TF
authors.lastname: Leung
authors.forename: Kam Lau
authors.initials: KL
authors.lastname: Cheung
authors.forename: Pak Cheung
authors.initials: PC
authors.lastname: Ng
mesh_terms: D001990:Bronchiolitis, Viral / Q000150:complications* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007362:Intensive Care Units; D008297:Male; D009017:Morbidity; D011024:Pneumonia, Viral / Q000150:complications* / Q000453:epidemiology; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors