[Protective effects of low dose nitric oxide inhalation on lung ischemia/reperfusion injury during cardiopulmonary bypass surgery].

OBJECTIVE

Out aim is to study the effects of inhaling nitric oxide(NO) on the pulmonary ischemia/reperfusion injury during cardiopulmonary bypass surgery.

METHODS

Cardiac valve replacement was performed on twenty patients with chronic rheumatic heart valve disease under cardiopulmonary bypass, and they were randomly divided into two groups: control group(n = 10) and NO group(n = 10). We monitored the following: mean pulmonary arterial pressure(MPaP), pulmonary vascular resistance(PVR), peak airway pressure (PAP), cyclic guanosine monophosphate(cGMP), inter-cellular adhesion molecule-1(ICAM-1), xanthinoxidase (XOD), malondialdehyde(MDA), PaO2 and the duration of post-operative mechanical ventilation.

RESULTS

The PAP, MPaP and PVR in the control group were much higher than those in NO group after reperfusion(P < 0.05). The durations of postoperative mechanical ventilation in NO group were shorter than those in the control group(P < 0.01). The cGMP and PaO2 after reperfusion in NO group were higher(P < 0.01), and the ICAM-1, XOD, MDA were lower(P < 0.05) than those in the control group.

CONCLUSIONS

1. If aortic clamp time is over 1 h, lung ischemia/reperfusion injury may occur during cardio-pulmonary bypass surgery. 2. Inhaling 20 ppm NO in the early phase of reperfusion has protective effects on the lung ischemia/reperfusion injury during cardio-pulmonary bypass surgery. 3. The mechanisms of the protective effects may be related with the increase of cGMP and the decrease of ICAM-1, XOD, MDA.