Tham khảo tài liệu 'chapter 112. venous thrombosis (part 5)', y tế - sức khoẻ, y học thường thức phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Chapter 112. Venous Thrombosis Part 5 Withholding further diagnostic testing and anticoagulant treatment in those patients with an unlikely clinical probability and a normal D-dimer level which constitutes 30-50 of all referred patients is safe. The remaining patients need to undergo repeated compression ultrasonography. An alternative approach is to perform a whole-leg imaging test on the day of referral. The advantage of this approach is that it eliminates the need for a repeat test and may even obviate the probability assessment and D-dimer testing . The major disadvantage is the detection and likely treatment of a substantial number of isolated calf DVTs that may otherwise have lysed spontaneously. Pulmonary Embolism The signs and symptoms of PE such as dyspnea pleuritic chest pain cough and hemoptysis are nonspecific and as for DVT insufficiently accurate to confirm or refute the diagnosis of PE. The classic gold standard is pulmonary angiography which is an invasive method requiring expertise. Hence very similar to the developments in the diagnosis of DVT two complementary strategies have evolved. The first is the combination of the assessment of clinical probability and the measurement of the D-dimer blood level the second is the introduction of spiral CT of the chest. The clinical probability can be categorized accurately using the rule developed for suspected PE Table 111-2 . In those with an unlikely probability a D-dimer test should be performed and if normal the disease can be safely ruled out and no anticoagulant therapy is indicated. Depending on the referral pattern of patients this combination rules out PE in 30-60 of all referred patients. Those with either a likely clinical probability at presentation or an abnormal D-dimer and unlikely probability need to undergo an imaging test. At present the most attractive method is the multi-slice spiral CT of the chest. This technique accurately detects pulmonary embolism and if normal has been shown to .
