Zeitschrift für neuartige Physiotherapien

Abstrakt

Validation of a Preoperative Risk Model for Pneumonia in Patients undergoing CABG Surgery

Hulzebos HJ, Buuren SV, Klarenbosch JV, Gigengack-Baars A, Brutel de la Riviere, Helders PJM and Meeteren NLUV

Background: Postoperative pulmonary complications (PPCs) are among the most frequently reported complications of Coronary Artery Bypass Graft (CABG) surgery. However, the risk to develop a PPC is not the same for all patients. The aim of this study was to validate a previously developed preoperative six-factor pulmonary risk model (age>70 years; productive cough, smoking, diabetes mellitus, inspiratory vital capacity > 75% predicted and maximum expiratory mouth pressure>75% predicted) to predict pneumonia, in patients undergoing CABG surgery.

Methods: Prospectively collected data for 421 adult patients who had undergone elective CABG surgery, in a university medical center in the Netherlands, were used to validate the preoperative risk model for predicting pneumonia. The accuracy of the model was tested by comparing the expected and observed incidence of pneumonia in each patient.

Results: Of the 421 patients, 227 (54%) were classified as being at high pulmonary risk, 24 (11%) of whom developed pneumonia. Only 4 of the 194 (2%) patients classified as being at low pulmonary risk developed pneumonia (OR=5.6; 95%CI, 1.9 to 16.5). The sensitivity (SE) was equal to 0.86, at a specificity (SP) of 0.48, both close to the values calculated for the development sample (SE=0.87, SP=0.56). The negative predictive value (NPV) was 0.98 and the area under curve (AUC) of the receiver-operating characteristics (ROC) curve was 0.76. The model that includes only the four anamnestic risk factors (age≥ 70 year, productive cough, smoking and diabetes mellitus) had an AUC equal to 0.75, with a SE=0.75, SP=0.62, and NPV=0.97.

Conclusion: The study confirms the diagnostic accuracy of the preoperative six-factor pulmonary risk model in an independent sample. Both the six-factor and even the simple anamnestic four-factor models are accurate in identifying preoperative patients at risk of developing pneumonia undergoing CABG surgery.