Beneficial effects of inhaled nitric oxide in hypoxaemic patients after coronary artery bypass surgery.
OBJECTIVE
Arterial oxygenation may be impaired in the early period after open-heart surgery, with an associated increase in ventilation time, morbidity and hospital stay. We tested the hypothesis that inhaled nitric oxide could be a useful therapeutic adjunct in this setting. We sought to establish clinical benefits (if any), safety and the appropriate dose range of inhaled nitric oxide therapy in hypoxaemic patients after coronary artery bypass graft surgery.


METHODS
Forty patients who satisfied our definition of post-operative impaired oxygenation were prospectively randomised. The treatment group (n = 20) received nitric oxide in addition to ventilatory support. While the control group (n = 20) was managed only by conventional ventilatory support. Cardio-respiratory parameters and clinical outcome measures were compared.


RESULTS
We determined the optimum concentration of inhaled nitric oxide as 20 ppm in the majority (60%) of patients. Treatment improved arterial oxygenation (8.4 +/- 1.4 kPa before, 11.8 +/- 1.5 kPa after 4 h, P < 0.001) and this benefit was sustained with lower oxygen fractions required at 24 h (P < 0.001). A significantly shorter period of mechanical ventilation was required in the treatment group (mean ventilation hours 67.0 +/- 5.9 vs. 85.0 +/- 6.5, P < 0.05), although the study did not have the power to distinguish differences in ITU or overall hospital stay. Nitrous oxide and met-haemoglobin levels did not rise appreciably.


CONCLUSIONS
We have established the safety and efficacy of inhaled nitric oxide, at a dose of between 10 and 30 ppm, in this group of patients. We suggest that nitric oxide and a delivery system are useful adjuvants in a cardiac surgical intensive care unit.
Prendergast
B
B
Royal Hospital For Sick Children NHS Trust, Edinburgh, UK.
Scott
D H
DH
Mankad
P S
PS
D000280:Administration, Inhalation; D000368:Aged; D001026:Coronary Artery Bypass; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000188:drug therapy / Q000628:therapy*; D008297:Male; D009569:Nitric Oxide / Q000008:administration & dosage* / Q000627:therapeutic use; D011182:Postoperative Care; D011183:Postoperative Complications / Q000188:drug therapy / Q000628:therapy*; D011446:Prospective Studies; D012121:Respiration, Artificial; D013997:Time Factors; D016896:Treatment Outcome
D009569:Nitric Oxide