文摘
Objective This study was carried out to evaluate effect of low volume normal frequency ventilation during Cardiopulmonary Bypass (CPB) on immediate postoperative respiratory outcome in patients undergoing elective open heart surgeries. Background Lung deflation during CPB is considered as major cause of postoperative pulmonary dysfunction. Various methods of ventilation had been tried during CPB to prevent postoperative lung dysfunction. As yet, little information is available comparing low volume normal frequency ventilation with no ventilation during CPB. Patients and Methods Thirty six patients aged 18?years to 65?years were included and randomized into two groups; Group V (n--8) or Group NV (n--8). Group V patients were ventilated with a tidal volume of 2?mL?kg?with 100?% oxygen during CPB after aortic clamp placement, and respiratory rate was continued as per pre CPB period. Ventilation was discontinued in NV group after aorta was cross clamped. Normal ventilation was restored in both groups after release of aortic clamp. Results Intraoperative PaO2 and PaCO2 were similar in both groups. The group V patients had improved inspiratory capacity (p--.0) in both day 1 (after extubation) and day 2 (24?h after extubation). Extubation was significantly earlier in group V patients (p-lt;-.05). Conclusion Low volume normal frequency ventilation during cardiopulmonary bypass improves lung mechanics during early postoperative period in patients undergoing open heart surgery.