7. Inhaled Nitric Oxide for Adult Respiratory Distress Syndrome Following Pulmonary Resection
Douglas J. Mathisen*, Elbert Y. Kuo, Chiwon Hahn, Ashby C. Moncure, John C. Wain, Hermes C. Grillo, William Hurford*, and Cameron W. Wright, Boston, MA

The adult respiratory distress syndrome (ARDS) developing after pulmonary resection is usually a lethal complication. The etiology of this serious complication remains unknown despite many theories. The presentation is insidious with a progressive downhill course. Intubation, aspiration bronchoscopy, antibiotics, and diuresis have been the mainstays of treatment. Mortality rates from adult respiratory distress syndrome after pneumonectomy have been reported as high as 90%. This was consistent with our experience with seven patients treated from 1987-1993 (85.7% mortality).

In 1993, nitric oxide became clinically available. We instituted an aggressive program to treat patients with ARDS after pulmonary resection. Patients were intubated and treated with standard measures plus inhaled nitric oxide at 10 to 20 parts/million. All patients had postural adjustments to improve ventilation/perfusion matching and management of secretions. Systemic steroids were given to half of the patients.

Ten consecutive patients following pulmonary resection (8 pneumonectomies, 1 lobectomy, 1 bilobectomy) with severe ARDS (ARDS score = 3.1±0.04) were treated. The mean PaO2/FiO2 ratio at initiation of treatment was 95.2±13.6 mmHg (Mean±SEM) and immediately improved to 127.6±24.0 mmHg, a 31.0±8.1% improvement (p<0.05). The ratio continued to improve steadily:

NO Therapy Baseline Immediate 24 hours 48 hours 72 hours 96 hours
PaO1/FiO2  95.2±13.6  127.6±24.0  177.6±22.2  196.8±23.4  202.4±20.8  213.4±27.9
p value 0.03 0.003 <0.001 <0.001 <0.0001

Chest x-rays improved in all patients and normalized in eight. No adverse reactions to nitric oxide were observed. No patients died as a direct result of ARDS (there were 3 deaths from late sepsis). The benefit of steroids was not statistically significant (p>0.05).

We recommend the following treatment regimen for this lethal complication: (1) intubation at the first radiographic sign of ARDS; (2) immediate institution of inhaled nitric oxide (10 to 20 parts/million); (3) postural changes to improve management of secretions and ventilation/perfusion matching; (4) diuresis and antibiotics; (5) consideration of the addition of intravenous steroid therapy. This regimen has improved oxygenation in all patients (p<0.001) and improved mortality compared to therapy prior to the availability of nitric oxide (p<0.05).