Risk factors for pulmonary complications, including pulmonary embolism, after total knee arthroplasty (TKA) in elderly Koreans

There has been a steady increase in elective TKA in elderly Koreans. However, there are few reports about the incidence of and risk factors for pulmonary complications, including pulmonary thromboembolism in these patients. We evaluated retrospectively 338 patients aged 60 years and over (290 females, median age 69 years) to assess the incidence and predictive factors for pulmonary complications, including pulmonary thromboembolism after TKA. Of these patients, 264 underwent simultaneous bilateral TKA (78%) by two surgeons and 56 (17%) had general anesthesia. No patient received thromboprophylaxis. There were 49 postoperative pulmonary complications in the 338 patients (14.2%, 49/338). Of the 49 patients, 27 developed atelectasis (27/49), six developed pneumonia (6/49), and four had pleural effusions (4/49) within 7 days of the surgery; 12 patients had a pulmonary thromboembolism (12/49) during their hospitalization. No pulmonary complication was fatal. Multivariate analysis revealed that pulmonary hypertension (right ventricular systolic pressure≥35mmHg on transthoracic echocardiography; odds ratio (OR)=3.0, p=0.016) was independently associated with pulmonary complications. A resting PaCO₂≥45mmHg (OR=22.9, p=0.004) was the only independent predictor of the development of a pulmonary thromboembolism. Pulmonary hypertension may thus predict pulmonary complications and a PaCO₂ greater than 45mmHg may be a risk factor for pulmonary thromboembolism following TKA. Preoperative blood gas analysis and transthoracic echocardiography can identify those patients at high risk for pulmonary complications, including pulmonary thromboembolism, after TKA in elderly Korean patients.