Application Of Noninvasive Bilevel Positive Airway Pressure Ventilation In Acute Left Ventricular Failure After Coronary Artery Bypass Grafting Surgery

Objctive To eveluate the effects of noninvasive bilevle positive airway pressure(BiPAP) on acute left ventricular failure after coronary artery bypass grafting surgery (CABG) .Methods 40 patients with acute left ventricular failure after coronary artery bypass grafting surgery were randomly divided into two groups. 20patients in control group just received conventional treatment and 20 patients in treatment group received BiPAP based on conventional treatment. The symptoms, signs, chest X-ray appearance, arterial blood gas analysis and heart failure classification were monitored and analyzed.Results Five patients were withdrawn on the basis of clincal results(2 patients in treatment group,three in control group). 30 minutes after noninvasive bilevle positive airway pressure ventilation (NIPPV) led to rapid improvement in respiratory rates, heart rates and SpO₂(%) compared with control group(P<0.05). Significant changes can be found in treatment group compared with control group after treatment at l,3,6h(P<0.01).They are shown in pH, PaO₂, PaCO₂,SaO₂,HR,RR and so on, especially in improving PaO₂ at early period vs. control group(P<0.01). The clinical improving time(defined as a clinical improvement with oxygen saturation of 96% ormore and respiratory rate less than 30 breaths/min) was significantly shorter in the treatment group (40+15 vs 88±27 min, PO.01). NIPPV led to a rapid improvement in oxygenation in the first 1 to 6 hours. Blood pressure had significant changes after treatment but did not show significant difference between the two group. There were differences between the treatment group and control group for total effective rate at 1 and 6 hour: 78% vs 35%(P<0.05),94% vs 65%(P<0.05), respectively,but no difference at 24 hour, 100%vs94% (P>0.05) .Conclusions For patients with acute left ventricular failure after coronary artery bypass grafting surgery, NIPPV could improve ventilation/perfusion mismatch and relieve dyspnea rapidly. It could improve cardiac function, pulmonary edema and hypoxemia more rapidly than conventional oxygen therapy.