Validity of index of suspicion for pulmonary embolism after hip arthroplasty.

Pulmonary embolism after total hip arthroplasty is problematic, and intravenous heparin treatment in the absence of pulmonary embolism carries risk. Algorithms for treating pulmonary embolism often cite clinical index of suspicion as a basis for initiating intravenous heparin, but most information regarding variables to predict pulmonary embolism originate from studies of patients rather than only from patients who had arthroplasty. We studied the hypothesis that a more homogenous subpopulation, patients who had total hip arthroplasty, may have findings more accurately predictive of pulmonary embolism. One hundred fifty records of patients who had total hip arthroplasty who were suspected of having pulmonary embolism and who were evaluated for pulmonary embolism were assessed. Complaints, physical findings, heparinization status, and test results were analyzed with univariate and multivariate assessments to determine predictors of pulmonary embolism. No significant differences were found between patients with or without pulmonary embolism regarding subjective complaints, physical examination, blood gas results, electrocardiogram findings, radiographs of the chest, and imaging of the veins of the legs. All attempts to model these variables into an index of suspicion that accurately predicted pulmonary embolism were unsuccessful. We advise adherence to established treatment algorithms rather than clinical suspicion when deciding whether to initiate heparin therapy.