Mechanically ventilated children with 2009 pandemic influenza A/H1N1: results from the National Pediatric Intensive Care Registry in Japan.
OBJECTIVE
To outline the characteristics, clinical course, and outcome of pediatric patients requiring mechanical ventilation with influenza A/H1N1 infection in Japan.


METHODS
Prospective case registry analysis.


METHODS
Eleven pediatric or general intensive care units in Japan.


METHODS
Consecutive patients infected with A/H1N1, aged from 1 month to 16 yrs old admitted to the intensive care unit for mechanical ventilation between July 2009 and March 2010.


METHODS
None.


RESULTS
Eighty-one children, aged 6.3 [0.8-13.6] (median [interquartile range]) years, were enrolled. Seventy-four (91%) had mechanical ventilation with tracheal intubation. Median duration of mechanical ventilation was 4 days (range 0.04-87) and 18 patients (23%) required mechanical ventilation >7 days. Two patients (2%) required extracorporeal membrane oxygenation. The in-hospital mortality was 1%. Forty-one patients (50%) had at least one underlying chronic condition, including 31 with asthma. Associated clinical symptoms and diagnosis were as follows: acute respiratory distress syndrome (9%), asthma or bronchitis (37%), pneumonia (68%) with 8 (14%) having bacterial pneumonia, neurological symptoms (32%), myocarditis (2%), and rhabdomyolysis (1%). Therapeutic interventions include inotropic support (21%), methylprednisolone therapy (33%), and antimicrobial therapy (88%). Multivariate analysis revealed that inotropic support was the only statistically significant factor associated with mechanical ventilation for more than a week (odds ratio 5.5, 95% confidence interval 1.5-20.5, p = .005).


CONCLUSIONS
The clinical presentations of pediatric patients requiring mechanical ventilation for A/H1N1 in Japan were diverse. In-hospital mortality of this population was remarkably low. Rapid access to medical facilities in combination with early administration of antiviral agents may have contributed to the low mortality in this population.
Department of Intensive Care Medicine, Osaka City General Hospital, Osaka, Japan.
Natsuko
N
Tokuhira
Nobuaki
N
Shime
Miho
M
Inoue
Tatsuya
T
Kawasaki
Yoshio
Y
Sakurai
Norimasa
N
Kurosaka
Ikuya
I
Ueta
Satoshi
S
Nakagawa
D000293:Adolescent; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D000998:Antiviral Agents / Q000627:therapeutic use; D001249:Asthma / Q000150:complications; D001991:Bronchitis / Q000150:complications; D002316:Cardiotonic Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications / Q000401:mortality / Q000628:therapy* / Q000821:virology*; D015278:Intensive Care Units, Pediatric; D007564:Japan / Q000453:epidemiology; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use; D015999:Multivariate Analysis; D009205:Myocarditis / Q000150:complications; D058873:Pandemics; D011014:Pneumonia / Q000150:complications; D011446:Prospective Studies; D012042:Registries; D012121:Respiration, Artificial; D012206:Rhabdomyolysis / Q000150:complications; D045169:Severe Acute Respiratory Syndrome / Q000150:complications; D013997:Time Factors
D000893:Anti-Inflammatory Agents; D000998:Antiviral Agents; D002316:Cardiotonic Agents; D008775:Methylprednisolone