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 FiO2 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.