On admission, the child was alert, smiling, and experiencing no toxic effects. Percutaneous oxygen saturation was 94% in room air, the rectal temperature was 37.4°C, and other vital signs were normal. Physical examination revealed mild dyspnea and tachypnea with grunting. There were diminished breath sounds in the left lower chest. The complete blood cell count was in the reference range. No leukocytosis or left shift was observed in the white blood cell count.