A pediatric case developing critical abdominal distension caused by a combination of humidified high-flow nasal cannula oxygen therapy and nasal airway

BACKGROUND: We describe a pediatric patient who suffered from critical abdominal distention caused by a combination of humidified, high-flow nasal cannula (HHFNC) oxygen therapy and nasal airway. CASE PRESENTATION: A 21-month-old boy with a history of chronic lung disease was admitted to the intensive care unit (ICU). Immediately after admission, his airway was established using a tracheal tube and mechanical ventilation was started. Five days after the commencement of mechanical ventilation, finally, his trachea was extubated. Immediately after extubation, HHFNC therapy at 20 L/min with an FiO(2) of 0.35 was applied. However, severe stridor was observed, then a nasal airway was placed in the left nostril. However, he became restless. Critical abdominal distention was observed. A subsequent chest X-ray revealed that the nasal airway was placed too deeply, and the gastrointestinal air was severely accumulated. Immediately, the nasal airway was removed, and HHFNC flow was reduced to 10 L/min. Frequent suctioning and continuous gastric drainage were required, which achieved gradual improvement of respiratory condition. CONCLUSIONS: We need to recognize that HHFNC therapy is one of the positive pressure ventilation system. Therefore, HHFNC therapy might cause the similar adverse events to noninvasive pressure ventilation.