High-flow oxygen via tracheostomy facilitates weaning from prolonged mechanical ventilation in patients with restrictive pulmonary dysfunction: two case reports.

BACKGROUND: Weaning from prolonged mechanical ventilation is extremely difficult in tracheostomized patients with restrictive pulmonary dysfunction. High-flow oxygen via tracheostomy supplies heated and humidified oxygen gas at > 10 L/minute. However, little has been reported on the use of high-flow oxygen via tracheostomy during weaning from ventilators in patients with restrictive pulmonary dysfunction. We report successful weaning from ventilators in patients with restrictive pulmonary dysfunction using high-flow oxygen via tracheostomy.

CASE PRESENTATION: The first patient is a 78-year-old Japanese man with severe pneumococcal pneumonia who was mechanically ventilated for more than 1 month after esophagectomy for esophageal cancer. After he underwent tracheostomy because of prolonged mechanical ventilation, restrictive pulmonary dysfunction appeared: tidal volume 230-240 mL and static compliance 14-15 mL/cmH2 O with 10 cmH2 O pressure support ventilation. He was weaned from the ventilator under inspiratory support with high-flow oxygen via tracheostomy over a period of 16 days (flow at 40 L/minute and fraction of inspired oxygen of 0.25). The second patient is a 69-year-old Japanese man who developed aspiration pneumonia after esophagectomy and received prolonged mechanical ventilation via tracheostomy. He developed restrictive pulmonary dysfunction. High-flow oxygen via tracheostomy (flow at 40 L/minute with fraction of inspired oxygen of 0.25) was administered with measurement of the airway pressure and at the entrance of the tracheostomy tube. The measured values were as follows: 0.21-0.3 cmH2 O, 0.21-0.56 cmH2 O, 0.54-0.91 cmH2 O, 0.76-2.01 cmH2 O, 1.17-2.01 cmH2 O, and 1.76-2.01 cmH2 O at 10 L/minute, 20 L/minute, 30 L/minute, 40 L/minute, 50 L/minute, and 60 L/minute, respectively. The airway pressures were continuously positive and did not become negative even during inspiration, suggesting that high-flow oxygen via tracheostomy reduces inspiratory effort. He was weaned from the ventilator under inspiratory support with high-flow oxygen via tracheostomy over a period of 12 days.

CONCLUSIONS: High-flow oxygen via tracheostomy may reduce the inspiratory effort and enhance tidal volume by delivering high-flow oxygen and facilitate weaning from prolonged mechanical ventilation in patients with restrictive pulmonary dysfunction.