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Medline ® Abstracts for References 3,21,22

of 'Perioperative management of patients receiving anticoagulants'

3
TI
Oral anticoagulation in surgical procedures: risks and recommendations.
AU
Torn M, Rosendaal FR
SO
Br J Haematol. 2003;123(4):676.
 
Surgery in anticoagulated patients is problematic. Coumarin therapy is often discontinued or reversed to reduce the perioperative bleeding risk. Meanwhile, the thromboembolic risk is enhanced. We sought to determine the frequency of bleeding and thromboembolism in anticoagulated patients undergoing routine surgery and to investigate the role of patient characteristics and the level of anticoagulation. We studied patients who attended the Leiden Anticoagulation Clinic for treatment relating to mechanical heart valve prostheses, atrial fibrillation or myocardial infarction and underwent surgery at the Leiden University Medical Centre between 1994 and 1998. Outcome events were bleeding and thromboembolism in the perioperative period. Seventy-two complications occurred in 603 interventions, yielding an overall frequency of 11.9% [95% confidence interval (CI): 9.3-14.9], 9.5% (n = 57) for haemorrhage and 2.5% (n = 15) for thromboembolism. Younger patients tended to have more complications [odds ratio (OR) for>65 years of age: 0.5, 95% CI 0.3-1.0]as did patients with atrial fibrillation (OR for atrial fibrillation versus mechanical heart valve prostheses: 1.8, 95% CI 0.8-4.2). High postoperative levels of anticoagulation were associated with a slightly increased risk of complications [OR international normalized ratio (INR)>3 vs. INR<2: 1.3, 95% CI 0.6-3.0]. We conclude that routine surgery in anticoagulated patients yields a high perioperative bleeding and thromboembolic risk. While neither patient characteristics nor the level of anticoagulation appeared to play a major role in the occurrence of complications, the risk was clearly associated to the type of surgery, with the highest risk in thoracic surgery.
AD
Department of Haematology, Leiden University Medical Centre, Leiden, The Netherlands.
PMID
21
TI
Identification of risk factors for bleeding during treatment of acute venous thromboembolism with heparin or low molecular weight heparin.
AU
Nieuwenhuis HK, Albada J, Banga JD, Sixma JJ
SO
Blood. 1991;78(9):2337.
 
In a prospective double-blind trial, we treated 194 patients with acute venous thromboembolism with heparin or low molecular weight heparin (LMWH; Fragmin). To evaluate the most important prognostic factors for bleeding, the presenting clinical features of the patients, the patients' anticoagulant responses, and the doses of the drugs were analyzed using univariate and multivariate regression analyses. No significant differences in clinical risk factors associated with bleeding were observed between heparin and LMWH. The univariate analyses ranked the parameters in the following order of importance: World Health Organization (WHO) performance status, history of bleeding tendency, cardiopulmonary resuscitation, recent trauma or surgery, leukocyte counts, platelet counts, duration of symptoms, and body surface area. Patients with WHO grade 4 had an eightfold increase in risk of bleeding as compared with WHO grade 1. Assessment of the individual contribution of each variable using multivariate regression analysis showed that the WHO performance status was the most important independent factor predicting major bleeding. A history of a bleeding tendency, recent trauma or surgery, and body surface area were also independent risk factors. The risk of bleeding was influenced by two factors related to the treatment, the patient's anticoagulant response as measured with the anti-Xa assay and the doseof the drug expressed as U/24 h/m2. An increased risk of bleeding was only observed at mean anti-Xa levels greater than 0.8 U/mL for both drugs. Significantly more major bleedings occurred in patients treated with high doses of the drugs, an observation that was independent of the concomitant anti-Xa levels. It should be considered whether choosing an appropriate initial dose adapted to the patient's body surface area and clinical risk factors can improve the efficacy to safety ratio of heparin treatment.
AD
Department of Hematology, University Hospital Utrecht, The Netherlands.
PMID
22
TI
Hemorrhagic complications of anticoagulant treatment.
AU
Levine MN, Raskob G, Landefeld S, Hirsh J
SO
Chest. 1995;108(4 Suppl):276S.
 
AD
PMID