Radiological diagnosis of deep vein thrombosis

Orthopaedic surgeons and thromboprophylaxis

OBJECTIVE

To assess attitudes to the use of thromboprophylaxis among orthopaedic surgeons in the United Kingdom.

DESIGN AND SUBJECTS

Single page postal questionnaire to all 926 active orthopaedic surgeons who are members of the British Orthopaedic Association.

RESULTS

The response rate was 70% (659 surgeons), of whom 595 (90%) used some form of prophylaxis. Most (548; 83%) used drugs but 47 (7%) used only elasticated stockings. A history of thromboembolic disease, hip surgery, and obesity was seen as the main risk factor. Ineffectiveness was the principal reason for not using prophylaxis.

CONCLUSIONS

Most orthopaedic surgeons use regimens of thromboprophylaxis, though many of these are of limited value. Improvements in the efficacy and safety of prophylactic agents, combined with ease of administration, would increase the use of such agents and make orthopaedic surgery safer for the patient.

Thromboembolism and its management in pregnancy

OBJECTIVES

To formulate recommendations for the management of thromboembolism during pregnancy.

DATA SOURCES

The English language published literature derived from Medline and covering the following aspects of thromboembolism in pregnancy was reviewed: epidemiology; pathogenesis; clinical features; investigations; the pharmacology of various anticoagulants; management and prophylaxis of deep vein thrombosis and pulmonary embolism; medicolegal aspects.

STUDY SELECTION

Publications published between 1960 and 1990 were cited. These studies were selected because data appeared reliable and with appropriate conclusions.

DATA SYNTHESIS AND CONCLUSIONS

Many questions are still not completely resolved, but the information gathered should provide firm guidelines to practitioners in the areas of diagnosis, the choice of anticoagulant drugs, methods of administration of the drugs, and measurement of therapeutic endpoints.

The role of emergency venography in the diagnosis and management of deep venous thrombosis

A retrospective study of patients who had undergone venography for suspected deep venous thrombosis during a six month period was undertaken to assess the influence of the examination on the subsequent management. Of these patients 38.6% had evidence of thrombus confirmed by the examination. This figure is comparable with other published results and did not bear out the impression that too many negative venograms were being obtained. Objective diagnosis of deep venous thrombosis is essential to ensure safe and cost-effective management. Other techniques have been advocated for the diagnosis of this condition but all have significant disadvantages compared with venography.

Hyaluronan (hyaluronic acid) in bronchoalveolar lavage fluid during the development of bleomycin-induced alveolitis in the rat

Hyaluronan (hyaluronate or hyaluronic acid) was measured in bronchoalveolar lavage (BAL) fluid from rats during a 30-day period after a single intratracheal dose of bleomycin. An increase of hyaluronan (HA) in BAL fluid was apparent by 3 days after bleomycin administration. Peak HA values were reached on Day 5 and were about 75 times higher than in control animals. Analyses of urea in BAL and HA in serum indicated that the increased levels of HA in BAL, postbleomycin, could not be explained by plasma leakage. The HA recovered by lavage decreased progressively after Day 5 and returned to normal 3 wk after bleomycin treatment. The HA content and an increased influx of PMN in BAL fluid were correlated and showed a similar time dependence, suggesting that enhanced synthesis of HA in the smaller airways is linked to the early inflammatory phase of the bleomycin injury.

Real-time ultrasound for diagnosis of symptomatic venous thrombosis and for screening of patients at risk: correlation with ascending conventional venography

This is a prospective study of 108 patients in two distinct groups undergoing real-time ultrasonography (US) and ascending conventional venography within the same day. The two patient groups consisted of the following: Those patients evaluated because of suspicion of deep venous thrombosis of lower limbs (69 patients) and those at high risk for venous thrombosis (19 patients with a recent hip fracture, 20 with a suspected pulmonary embolism). In the diagnosis group 48 patients had venographic evidence of thrombosis. The predictive value of abnormal findings from real-time US was 97%, and that of a negative study was 75%. Thus, real-time US may have a role as a diagnostic procedure, to be followed by x-ray venography in patients with negative US results. By contrast, real-time US is far less sensitive as a screening test in patients without clinical evidence of thrombosis. Only 3 of 9 patients with thrombosis were detected, with a 50% sensitivity for proximal vein thrombosis. Therefore, the use of real-time US for screening high-risk patients must be limited to very high risk patients in whom other tests are ineffective (as in hip surgery).

How do we know who has had deep vein thrombosis?

An attempt was made to identify all patients diagnosed as having deep vein thrombosis (DVT) in a large teaching hospital during one year. A review of the radiology records showed that 124 (81%) of the 154 venograms performed were for suspected DVT, and that the diagnosis was confirmed in 57 (46%). During the same period, the Hospital Activity Analysis (HAA) records revealed 174 episodes classified as 'phlebitis or thrombophlebitis' in 162 patients. Only 37 of these episodes (21%) had been confirmed by X-ray venography and at least 29 patients were incorrectly classified by HAA. 'Medical' patients accounted for 54% of the episodes of DVT, yet in only 25% of these was the diagnosis confirmed by venography, while 'surgical' DVTs were less frequent but were more often confirmed by venography.

Anticoagulant drugs in the elderly: valuable in selected patients

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Preoperative lower limb venography in patients undergoing total hip arthroplasty

Using bilateral ascending venography, the authors examined 93 consecutive patients undergoing total hip arthroplasty for the presence of asymptomatic preoperative leg vein thrombosis. Radiologic abnormalities were seen in only four patients, and this was not statistically significant (P greater than .1). There were no complications from the procedure. It is suggested that routine preoperative screening for deep vein thrombosis prior to hip arthroplasty is unnecessary but may be appropriate in patients at particularly high risk for thromboembolic complications.