Introduction: It is well established that a negative D-dimer will reliably rule out thromboembolism in selected low risk patients. Multiple modified D-dimer cutoffs have been suggested for older patients to improve diagnostic specificity. However, these approaches are better established for pulmonary embolism than for deep venous thrombosis (DVT). This study will evaluate the diagnostic performance of previously suggested D-dimer cutoffs for low risk DVT patients in the ED, and assess for a novel cutoff with improved performance. Methods: This health records review included patients >50 years with suspected DVT who were low-risk and had a D-dimer performed. Our analysis evaluated the diagnostic accuracy of D-dimer cutoffs of 500 and the age adjusted (age x 10) rule for patients >50 years; and 750, and 1,000 cutoffs for patients >60 years. 30-day outcome was a diagnosis of DVT. We also assessed the diagnostic accuracy for a novel cutoff (age x 12.5). Results: 1,000 patients (mean age 68 years; 59% female) were included. Of these, 110 patients (11%) were diagnosed with DVT. The conventional cutoff of <500 µg/L demonstrated a sensitivity of 99.1% (95% CI 95.0-99.9) and a specificity of 36.4% (95% CI 33.2-39.7). For patients >60 years, the absolute cutoffs of 750 and 1,000 showed sensitivity of 98.7% (95% CI, 92.9, 99.9), and the specificity increased to 48.6% (95% CI, 44.5-52.8%) and 62.1% (95% CI, 58.1-66.1%) respectively. For all study patients, age adjusted D-dimer demonstrated a sensitivity of 99.1% (95% CI 95.0-99.9) and a specificity of 51.2% (95% CI, 47.9-54.6). A novel age adjusted cutoff (age x 12.5) for patients >50, demonstrated a sensitivity of 97.3% (95% CI 92.2-99.4) and a specificity of 61.2% (95% CI 58.0-64.5). When compared to conventional cutoff, the age adjusted cutoffs (age x 10 and age x 12.5) would have resulted in an absolute decrease in further investigations of 13.1% and 22.2%, respectively, with false negative rates of 0.1% and 0.3%. Conclusion: Among older patients with suspected DVT and low clinical probability, the age adjusted D-dimer increases the proportion of patients among whom DVT can be ruled out. A novel cutoff (age x 12.5) demonstrated improved specificity. Future large scale prospective studies are needed to confirm this finding and to explore the cost savings of these approaches.

This article presents a case of a 43-year-old man with paradoxical embolism. The patient had simultaneous deep venous thrombosis, pulmonary embolism and bilateral limb-threatening arterial occlusions. The unifying diagnosis was paradoxical embolism through a previously undetected atrial septal defect. Suggestions for the evaluation and emergency management of paradoxical embolism are outlined, and the literature is briefly reviewed.

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are an important cause of morbidity and mortality in the surgical patient. The first guideline produced by the Scottish Intercollegiate Guidelines Network was for the prophylaxis of venous thromboembolism. Patients undergoing major head and neck cancer surgery commonly exhibit risk factors for venous thromboembolism. Currently, however, there are no data on its incidence in these patients. A questionnaire survey was performed to assess the current practice of consultant otolaryngologists regarding DVT prophylaxis in patients undergoing head and neck cancer surgery. Of those respondents who managed these patients, 57 per cent did not use routine DVT prophylaxis while 43 per cent did. A wide variety of techniques were employed among those practising DVT prophylaxis.

A consensus is needed concerning the use of thromboembolism prophylaxis in head and neck surgery patients.