Acute appendicitis is a common abdominal surgical emergency. About 6 to 7% of people around the world have had experienced appendicitis according to the statistics. This article describes a patient who was intubated and used a respirator after acute appendicitis complicated with peritonitis. The patient's intra-abdominal pressure increased because of abdominal distension during ventilator weaning training. When measuring the index of respirator detachment, the patient showed shallow breathing and a seesaw breathing pattern; the blood oxygen saturation concentration decreased, and thus the High Flow Nasal Cannula Oxygen Therapy (HFNC) was used immediately after extubation to avoid reintubation. Subsequently, the patient's breathing pattern improved, and the oxygen nasal cannula was replaced. The patient was discharged as scheduled. We share the respiratory care experiences through this case study.