Pulmonary function tests predict outcome after cardiac surgery

The aim of this study was to examine the value of systematic preoperative pulmonary function tests (PFTs) in order to reliably predict prolonged stay in I.C.U., prolonged mechanical ventilation and mortality in elective cardiac surgical patients. 149 consecutive adult patients (valvular replacement or coronary bypass graft) were studied retrospectively. We examined the preoperative respiratory data: vital capacity (VC), first second forced expired volume (FEV1), PaCO2 and PO2. Length of stay in I.C.U. (LICU), duration of mechanical ventilation (DMV), incidence of reintubation and survival rate were used as indices of respiratory morbidity. The results of the present study clearly indicate that patients with impaired airway flow rates had a prolonged postoperative recovery following cardiac surgery. Mortality, ICV and DMV increased when FEV1 was less than 1.5 L, VC was less than 2.5 L, or PaO2 was less than 8.5 kPa. Reintubation was associated with impaired flow rates. Pulmonary function tests appeared effective in predicting postoperative complications and the need for prolonged ventilatory support.