Objective    To assess the validity of non-invasive positive pressure ventilation in correcting impediments to weaning from mechanical ventilation in those patients who failed to be extubated after coronary artery bypass surgery.     Methods    Three hundred and sixty patients undergoing coronary artery bypass surgery during December 2005 to February 2010 were included in the study. Those patients were divided into non-invasive positive pressure ventilation group due to extubation failure (N group

n=21) and control group (C group

n=329). During noninvasive positive pressure ventilation

mean arterial pressure

heart rate

respiratory rate

arterial pH value

arterial oxygen saturation

pulmonary arterial pressure

arterial oxygen tension

oxygen/inspired oxygen fraction ratio and alveolar-arterial oxygen tension difference were measured at preoperative

8 and 0 h before noninvasive positive-pressure ventilation

and 8

16

24 and 48 h after ventilation.     Results    Elder age (older than 65 years)

current smoking

low arterial oxygen tension /fraction of inspired oxygen

low endogenous creatinine clearance rate

with 3 vessels involved and associated valvular disease may be the risk factors of extubation failure (P0.05). The percentages of more than 3 grafts

large blood transfusion

and appeal to ventilation during cardiopulmonary bypass in N group were much higher than those in C group (P0.05). Non-invasive positive pressure ventilation improved respiratory rate

arterial oxygen saturation

heart rate

pulmonary arterial pressure

oxygenation index

alveolararterial oxygen tension difference in N groups (P0.05). Noninvasive positivepressure ventilation had obvious efficiency on cardiogenic pulmonary edema

atelectasis and acute lung injury. There were 2 patients having lung inflammation

and one of them received reintubating. The total efficiency was 95.2% for non-invasive positive pressure ventilation.     Conclusion    In appropriate candidates

noninvasive positivepressure ventilation exerts favorable effects on lung function

early extubation and preventing reintubation.