A study to evaluate usefulness of biphasic extrathoracic cuirass ventilation (BCV) for acute respiratory failure in infants: a multicenter randomized controlled test with standard treatment as the control

INTERVENTION: Biphasic cuirass ventiration Control treatment CONDITION: respiratory tract infection PRIMARY OUTCOME: The rate of infants who required additional treatments, including mechanical ventilation (CMV, NPPV and BCV) due to respiratory distress induring 24 hours after treatent. SECONDARY OUTCOME: Blood gas analysis at 1 hour after treatment.; VAS(Visual analogue scale)1 hour after treatment. ; mPIS at 1,2 and 3 hours after treatment.; mPIS at 24 hours after treatment.; mPIS when BCV could be discontinued because of an improvement of symptoms.; mPIS when the management by positive pressure ventilation was started because of worsening of symptoms. ; The frequency of additional treatments due to worsening of symptoms during the periods from the entrance to the end of the trial.; Validity of of the timing to discontinue BCV.; The number of infants BCV was restarted because of wosening of symptoms. INCLUSION CRITERIA: The criteria of subjects in the present study were as following; Less than 2 years old sPO2 level was between the value of 90% or more and less than 95%. Those who were diagnosed as respiratory diseases including bronchitis, pneumonia, bronchiolitis and so on. A written consent was obtained from the guardian.