OBJECTIVETo summarize characteristics and outcomes of critically ill children with 2009 influenza A (H1N1).

METHODA prospective observational study of 14 critically ill children with 2009 influenza A (H1N1) in pediatric intensive care unit (PICU) in Suzhou between Oct. 1(st) 2009 and Dec. 25(th) 2009. The primary outcome measures included frequency and duration of mechanical ventilation and duration of ICU stay.

RESULTCritical illness occurred in 14 patients with confirmed (n = 14), community-acquired 2009 influenza A virus (H1N1) infection. The mean (SD) age of the 14 patients with confirmed 2009 influenza A (H1N1) was (4.91 ± 4.14) years, 7 were female (50.0%). The median duration from symptom onset to hospital admission was (3.09 ± 1.30) days and from hospitalization to ICU admission was (0.95 ± 0.96) day. All the patients were severely hypoxemic [mean (SD) ratio of PaO2/FiO2 was (191.27 ± 80.58) mm Hg] at ICU admission. ARDS occurred in 11 cases (78.6%). Mechanical ventilation was applied for 10 patients (71.4%). The median duration of ventilation was (12.51 ± 10.03) days and ICU stay was (12.58 ± 10.65) days. The median length of time during which the real-time RT-PCR test results were positive was (17.27 ± 5.57) days; Comorbidities such as iron deficiency anemia, cerebral palsy and congenital heart disease were found in 8 cases (57.1%). The longer length of mechanical ventilation and ICU stay were found in cases with higher admission PRISM III Score and lower Pediatrics Critical Illness Score.

CONCLUSIONCritical illness due to 2009 influenza A (H1N1) in Suzhou occurred rapidly after hospital admission and was associated with severe hypoxemia, ARDS, a condition that required prolonged mechanical ventilation. There were myocardial damages in critically ill children with severe 2009 influenza A (H1N1).