PREDICTION OF RESPIRATORY COMPLICATIONS F OLLOWING ABDOMINAL AORTIC-SURGERY

The most frequent type of complication in patients undergoing aortic s urgery is respiratory. Preoperative lung function (PFT) and arterial b lood gas measurement (ABG) are often carried out to assess the risk mo re precisely. The aim of the present retrospective study was to determ ine which value of lung function test could identify patients who deve loped such complications. ''Receiver Operating Characteristic'' (ROC) curves and the area beneath the curve for the diagnosis of respiratory complications were calculated for each variable of PFT and ABG. The g reatest Youden index for each variable was chosen as indicative pulmon ary function criterion of increased risk of pulmonary complications. O ne hundred and ninety-five patients (age: 65 +/- 10 years) were includ ed. Respiratory complications occurred in 15% of patients. Respiratory complications increased from 12% if the vital capacity (VC) was great er than or equal to 77% of the predicted value to 35% if the VC was <7 7% (P = 0.002), and from 10% if the FEV(1) was >76% to 34% if the FEV( 1) was greater than or equal to 76% (P = 0.0005). A decreased PaO2 or increased PaCO2 was not correlated with an increased incidence of resp iratory complications. Length of stay in ICU or in hospital were incre ased when VC or FEV(1) were low. Frequency of pulmonary complications was 9% in patients without PFT abnormalities, 16% in patients with eit her diminished VC or FEV(1) and 35% in patients with both lowered VC a nd FEV(1). However, all the areas under the ROC curves were <0.7 and t he sensitivity of the different variables was low. It is concluded tha t routine preoperative PFT and ABG cannot predict respiratory complica tions after abdominal aortic surgery.