Pressure limited ventilation with permissive hypoxia and nitric oxide in the treatment of adult respiratory distress syndrome.

In the management of adult respiratory distress syndrome pressure limited mechanical ventilation may protect the lungs from overdistention injury. Unacceptable hypoxia may be avoided by adding nitric oxide to the inspiratory gas, and thus make pressure limited ventilation easier to perform. There exists no consensus about an acceptable lower limit of SaO2, and in the present case we gave preference to pressure limitation at the cost of oxygenation. A young woman with severe adult respiratory distress syndrome was set on pressure limited mechanical ventilation with peak pressures of 35-38 cm H2O, PEEP of 10-12 cm H2O, and FiO2 of 0.95 with 20 ppm nitric oxide. SaO2 varied between 75 and 85%, and cardiac output ranged between 5.2 and 7.5 L min-1. Oxygen consumption was in the upper normal range, and she did not became acidotic. After 3 days, she started to improve. In conclusion, it seems that hypoxia might be well tolerated as long as the circulation is not compromised. It might prove beneficial to accept some hypoxia to avoid ventilator induced lung damage.