Pharmacological control of pulmonary blood flow with inhaled nitric oxide after the fenestrated Fontan operation.
BACKGROUND
A transient increase in pulmonary vascular resistance can result in hemodynamic compromise after a Fontan operation. An interatrial fenestration is designed to maintain cardiac output in these circumstances but may result in severe hypoxemia and a vicious circle due to hypoxemia induced pulmonary vasoconstriction. Our aim was to determine whether inhaled nitric oxide (iNO), a selective pulmonary vasodilator, could be used to reduce pulmonary vascular resistance in desaturated patients (SaO2 < or = 85%) after a fenestrated Fontan operation.


RESULTS
Responses to iNO (20 ppm for 15 min) were assessed in 10 consecutive children with SaO2 < or = 85% and compared with 5 with SaO2 > 85% after a fenestrated Fontan operation. Exposure to iNO resulted in a significant increase in SaO2 (from 64 +/- 5% to 82 +/- 2%, P < .01) and reduction in transpulmonary gradient (TPG) (from 12.2 +/- 1 [SEM] to 9.6 +/- 1.1, P < .01) in patients with baseline SaO2 < or = 85%. Baseline saturation was a predictor of response to iNO, with a greater response in those with lower saturations (r = -.86, P < .01). In contrast, no significant effects were noted in PaO2 or TPG (from 122 +/- 46 mm Hg and 8 +/- 1.8 to 123 +/- 43 mm Hg and 7 +/- 1.2, respectively) in patients with baseline SaO2 > 85%.


CONCLUSIONS
iNO improved both oxygenation and TPG in desaturated patients after the fenestrated Fontan operation, possibly by counteracting hypoxemia-induced pulmonary vasoconstriction. A trial of iNO should be considered in clinically unstable desaturated patients after the fenestrated Fontan operation.
Cardiothoracic Unit, Great Ormond Street Hospital for Children, London, UK.
A P
AP
Goldman
R E
RE
Delius
J E
JE
Deanfield
O I
OI
Miller
M R
MR
de Leval
P E
PE
Sigston
D J
DJ
Macrae
D000280:Administration, Inhalation; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D018729:Fontan Procedure / Q000009:adverse effects*; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007223:Infant; D009569:Nitric Oxide / Q000008:administration & dosage / Q000494:pharmacology*; D010100:Oxygen / Q000097:blood; D011652:Pulmonary Circulation / Q000187:drug effects*; D014655:Vascular Resistance
D009569:Nitric Oxide; D010100:Oxygen