Prolonged prophylaxis with unfractioned heparin is effective to reduce delayed deep vein thrombosis in total hip replacement.

The aim of this study was to assess the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) until 45 days after elective total hip replacement (THR) and the efficacy of prolonged unfractioned heparin (UH) prophylaxis up to postoperative day 30. To this end 79 of 96 patients admitted consecutively to the University Hospital of Pisa for THR were randomly assigned to short- or long-term UH prophylaxis. Sixty-one patients completed the study: 28 of them received short-term prophylaxis (subcutaneous UH 15,000 IU/24 h for 15 days) and 33 prolonged prophylaxis (subcutaneous UH 15,000 IU/24 h for 30 days). Lower limb phlebography was performed in all patients on day 45 after THR. DVT was demonstrated in 10 (16.3%) cases after hospital discharge. Among them, 2 patients also had symptomatic PE. The incidence of DVT was 21.4% in short- and 12.1% in long-term UH-treated patients. The incidence of only proximal DVT was 17.8% in short- and 3.0% in long-term UH-treated patients; although the difference was only close to significance (p = 0.085), the relative risk of developing proximal DVT was about six times greater in the former group of patients. We concluded that the risk for thromboembolism persists at least until 45 days after surgery in patients subjected to THR. Prophylaxis with UH given up to postoperative day 30 appears more effective and safer in reducing the delayed thromboembolic risk compared to prophylaxis with UH given up to discharge only.

Resolution of pulmonary embolism: effect of therapy and putative age of emboli.

The purpose of this study was to evaluate functional and scintigraphic improvement in patients with pulmonary embolism (PE) according to the kind of treatment and the putative age of the emboli. The study includes 20 patients with both scintigraphic and angiographic diagnosis of PE enrolled in Pisa as a part of two previous multicenter trials: PAIMS 2 and BAPE. All patients were admitted to the Pulmonary Unit of the University of Pisa and treated with recombinant tissue-type plasminogen activator (rt-PA) plus heparin (H) (n = 10) or with H alone (n = 10). Results confirmed previous data, namely that perfusion damage decreases significantly from embolization to 7 days later in both patients treated with rt-PA + H and H alone (p < 0.001), although patients treated with rt-PA + H have a significantly higher perfusion restoration (p < 0.001) and a standard PaO2 increase (p < 0.01). Interestingly, our data also showed that the putative age of the emboli does not influence the efficacy of rt-PA + H treatment, while it does influence that of H treatment alone; in other words, rt-PA + H therapy may act efficaciously not only in fresh, but also in old pulmonary emboli.

Clinical features of pulmonary embolism. Doubts and certainties.

The diagnosis of pulmonary embolism (PE) can be accurately made by perfusion lung scan and pulmonary angiography; however, when these diagnostic techniques are not promptly available, simple clinical procedures may be useful to identify patients with high probability PE. To this end, collection of clinical data through a standardized questionnaire and the use of findings from chest radiograph, ECG, and blood gas analysis may raise clinical suspicion and decide on therapeutic management. By reviewing published literature and our own experience, we found that unexplained dyspnea and chest pain are the most frequent symptoms, and sudden onset dyspnea and pleuritic chest pain are the most typical. Chest radiograph is abnormal in more than 80% of patients with PE, showing typical signs such as "sausage-like" descending pulmonary artery, Westermark sign, etc. The ECG may show findings characteristic of PE, such as tachycardia, T wave inversion in V1-V2, and PR displacement. Arterial blood gas data frequently demonstrate hypoxia and hypocapnia, being helpful in suspecting or excluding PE. Recent statistical techniques, such as discriminant or logistic analysis, may be applied to the above clinical assessment to refine and improve the noninvasive diagnosis of PE.

A way to select on clinical grounds patients with high risk for pulmonary embolism: a retrospective analysis in a nested case-control study.

We studied 196 patients with suspicion of pulmonary embolism (PE), subsequently confirmed in 98 by positive pulmonary angiography and excluded in 98 by normal or near-normal perfusion lung scan. Patients had a clinical questionnaire for history, and, soon after. a radiograph, blood gas analysis, and an ECG. Clinical and instrumental signs were matched in patients with confirmed and unconfirmed PE to find those more frequent in embolic patients and, thus, more characteristic of PE. The following were: previous PE, immobilization and thrombophlebitis (p < 0.05); dyspnea and cough (p < 0.05); enlarged descending pulmonary artery (DPA), enlarged right heart, pulmonary infarction, Westermark sign (p < 0.001), and elevated diaphragm (p < 0.05); hypoxemia. No ECG sign was more frequent in PE. Thereafter, all variables were processed separately with a logistic multiple regression analysis and those significantly associated to PE were tested in a final logistic model that was able to predict the actual result of angiography or scintigraphy; accordingly, previous PE, immobilization, thrombophlebitis, enlarged DPA, pulmonary infarction, Westermark sign, hypoxemia were significantly associated with a high risk of PE (from 2.8 to 15 times greater than in patients without these signs). Therefore, we may conclude that clinical assessment and noninvasive tests may help to detect patients at higher risk for PE where heparin coverage should be started while waiting for conclusive diagnostic procedures.

Clinical, anamnestic and coagulation data in patients with suspected or confirmed pulmonary embolism.

We studied 84 consecutive patients referred with the suspicion of pulmonary embolism (PE) to investigate the influence of clinical and hematological profiles on the diagnosis and severity of this disease and recovery. Diagnosis of PE was confirmed in 48 out of 84 patients by perfusion scintigraphy and/or pulmonary arteriography. Severity of PE and entity of recovery were investigated by measuring standard PaO2 on blood gas analysis and the number of unperfused lung segments ULS on perfusion scintigraphy. Most common clinical predisposing conditions were more frequent, though not significantly so, in embolic patients and a very low prevalence of PE was appreciable in patients without clear predisposing conditions. Among coagulation factors, only thrombin-antithrombin (TAT) complexes were twice as high in embolic as in nonembolic patients (14.0 +/- 13.6 vs. 7.0 +/- 4.2 ng/ml; p < 0.02), while there was no statistically significant difference between embolic and nonembolic patients for activated partial thromboplastin time, prothrombin time, antithrombin III, protein C, fibrinogen, plasminogen, alpha 2-plasmin inhibitor, and plasminogen activator inhibitor-1. Sensitivity and specificity of TAT complexes in diagnosis of PE were 95.8% and 30.5%, respectively. Therefore, normal values of TAT complexes may help exclude the diagnosis of PE, while abnormal values allow to reinforce the clinical suspicion of PE. No relation was found between coagulation parameters and the severity of PE. The follow-up of 48 patients with confirmed PE was favorable on the average; however, neither the presence of predisposing conditions nor abnormal coagulation parameters allow to predict the degree of functional and scintigraphic improvement during follow-up.