1、IPC預防婦科腫瘤術后靜脈血栓Prevention of Postoperative VenousThromboembolism by External Pneumatic CalfCompression in Patients With GynecologicMalignancyDANIEL L. CLARKE-PEARSON, MD, INGRID S. SYNAN, RN,WANDA M. HINSHAW, MS, R. EDWARD COLEMAN, MD, ANDWILLIAM T. CREASMAN, MDOne hundred seven patients undergoing

2、major surgery for gynecologic malignancy participated in a controlled trial evaluating the effectiveness of pneumatic calf compression in the prevention of postoperative deep venous thrombosis and pulmonary embolism. External pneumatic calf compression was applied intraoperatively and for five posto

3、perative days. All patients were prospectively screened for deep venous thrombosis with impedance plethysmography and 125 I-fibrinogen leg counting. Deep venous thrombosis and/or pulmonary emboli were detected in 18 of 52 control group patients (34.6%) whereas in seven of 55 (12.7%) of those treated

4、 with external pneumatic calf compression (P .005).External pneumatic calf compression was most effective during the first five days postoperatively and also reduced the incidence of deep venous thrombosis in patients at highest risk. When applied during surgery and for five days postoperatively, ex

5、ternal pneumatic calf compression significantly reduces the incidence of postoperative venous thrombosis. (Obstet Gynecol 63:92, 1984)The prevention of pulmonary emboli and deep venous thrombosis must be an important effort of the pelvic surgeon caring for the high-risk group of patients who have pe

6、lvic malignancies. Over the past decade investigators have found low-dose heparin to prevent fatal pulmonary emboli 1 and 125 I-fibrinogen-detected leg thrombi.2-4 These studies have led to a general recommendation of low-dose heparin prophylaxis for high-risk groups.5 Low-dose heparin has been foun

7、d to be ineffective in preventing venous thrombosis and pulmonary emboli after major surgery for gynecologic malignancies?6.7 Another prophylactic method, external pneumatic calf compression, has also been demonstrated to reduce leg thrombi,8-14 As compared with bleeding complications associated wit

8、h low dose heparin, pneumatic calf compression has no significant side effects. 1.15 The present study was undertaken to evaluate the efficacy of external pneumatic calf compression in prevention of deep venous thrombosis and pulmonary emboli in patients undergoing major surgery for gynecologic mali

9、gnancies. Materials and PatientsPatients admitted to the Division of Gynecologic Oncology, Duke University Medical Center, who were to undergo major surgery for known or presumed gynecologic malignancies were eligible to enter the study protocol. Excluded from study entry were patients who had recei

10、ved anticoagulants (heparin or sodium warfarin) within six weeks of surgery, or patients with acute venous thromboembolic complications. After obtaining informed written consent, a medical history was taken and a physical examination performed with particular emphasis on possible thromboembolic risk

11、 factors: age, race, stage and site of malignancy, concur-rent medical illnesses, a past history of deep venous thrombosis or pulmonary embolus, and current medications. Physical findings of venous varicosities, venous stasis changes, weight, and height were record-ed. Using a 1:1 allocation scheme,

12、 patients were randomly assigned to either a control group or external pneumatic calf compression group. The control group received no specific thromboembolic prophylaxis. Patients assigned to eternal pneumatic calf compression had the pneumatic sleeves applied at the time of induction of anesthesia

13、 in the operating room. External pneumatic calf compression was delivered by a pneumatic compressor (Venodyne, Lyne-Nicholson, Inc, Needham Heights, MA), which cycled to achieve a pressure of 40 to 45 mmHg delivered to sleeves emcompassing the calves of the patients legs. Duration of compression was

14、 12 seconds of every minute. Calf compression was maintained intraoperatively and throughout the first five postoperative days. The compression sleeves were removed only when the patient was out of bed to ambulate. Both groups of patients had the foot of their beds elevated 20 to 30 degrees and were

15、 encouraged to ambulate in the immediate post-operative period. From the Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, the Comprehensive Cancer Center Database, and the Department of Radiology, Duke University Medical Center, Durham, North Carolina.Because of the nature

16、of the therapeutic intervention studied, this trial could not be carried out in a double-blind fashion. In addition, the clinical diagnosis of deep venous thrombosis or pulmonary embolism is often erroneous. We therefore based the diagnosis of thromboemboli on objective noninvasive and invasive diag

17、nostic methods. No patient was considered to have developed thromboembolus based on clinical impression alone.Surveillance for clinically occult deep venous thrombosis was conducted by 125 l-fibrinogen counting and impedance plethysmography, 125 l-fibrinogen leg counting was performed at two-inch in

18、tervals over the deep veins of the thigh and calf as described by Flanc et al 16 and Kakkar.17 Preoperatively, four drops of super-saturated potassium iodide were administered orally or 100 mg of sodium iodide given intravenously to block thyroid uptake of 125 iodine. Immediately postoperatively, in

19、 the recovery room, 125 l-fibrinogen (100 uCi) was injected intravenously. On the first postoperative day, 12 to 24 hours after 125 I-fibrinogen administration, the condition of the patients legs was as sessed. All counts were normalized to the precordia count. 125 I-fibrinogen was counted on the fi

20、rst postoperative day and on alternate days until the patient was discharged from the hospital. If an area of increased activity suggestive of thrombosis was encountered, 125 fibrinogen counting was repeated daily. The diagnosis of deep vein thrombosis was made when the 125 iodine counts were increa

21、sed more than 20% ewer the adjacent scan site, over the same site on the contralateral leg, or over the previous days count at the same location with persistence of the increased count for two consecutive days. If the fibrinogen scan suggested thrombus formation in the popliteal region or thigh, asc

22、ending contrast, venography was per- formed to confirm deep venous thrombosis. 125I-fibrin-ogen-detected thrombosis in the calf was followed daily with 125 I-fibrinogen counting and impedance plethysmography. If the 125 l-fibrinogen-detected thrombus propagated to the poplitel region or if the imped

23、ance plethysmogram became abnormal, contrast venography was obtained. Ascending contrast venography was performed using the technique described by Rabinov and Paulin. 18Impedance plethysmography (IPG-200, StimTech Products by Codman and Schurtleff, Inc., Hingham, MA) was performed preoperatively and

24、 on the fifth postoperative day using the methods described by Wheeler et al 19 and the present authors? If an abnormal impedance plethysmogram was obtained, venography was used to confirm the occurrence and document the location and extent of deep vein thrombosis. Patients with clinical signs and s

25、ymptoms of deep vein thrombosis or pulmonary emboli were evaluated with venography, ventilation perfusion lung scanning, and/or pulmonary arteriography as wasappropriate to confirm the diagnosis.Patients with normal 125 l-fibrinogen studies, impedance plethysmography, and no clinical evidence of thr

26、omboembolic complications were assigned a final diagnosis of no thromboembolism. Those patients with 125 I-fibrinogen-detected calf thrombi that did not propagate to the popliteal region or more proximally were classified as having calf vein thrombosis. All other patients with either abnormal 125 l-

27、fibrinogen counting or an abnormal impedance plethysmogram underwent venography to achieve a final diagnosis.Patients with signs or symptoms of pulmonary emboli and those with proximal deep vein thrombosis underwent ventilation perfusion lung scanning. The diagnosis of pulmonary embolism was given t

28、o those patients with a high probability scan as defined by Biello et al. TM Patients with indeterminant lung scans underwent pulmonary arteriography and received a final diagnosis based on angiographic findings. Patients with normal or Iow probability lung scans received diagnoses of no pulmonary e

29、mbolism. Interpre-tation of venography, lung scans, and pulmonary arteriography was made by two radiologists unaware of the patients method Of thromboembolism prophylaxis or results of noninvasive surveillance.All patients were followed clinically for at least 42 days postoperatively. After hospital

30、 discharge, symptoms suggestive of deep venous thrombosis or pulmonary embolism were evaluated by appropriate noninvasive and invasive studies, as described above, to achieve a diagnosis. Any deep venous thrombosis or pulmonary embolism detected within the first 42 days postoperatively was included

31、as a postoperative thromboembolus.Statistical methods used contingency table analyses and associated 2 statistics to measure the effects of various risk factors on the incidence of thromboembolism. A multiple logistic regression analysis was used to test for treatment differences, adjusting for the

32、risk factors identified.Table 1. Summary of Patients Excluded After Study EntryTreatment group External pneumaticcalf compressionReason excluded from study ControlSurgery canceled 2 3Impedance plethysmography abnormal 1 1 preoperativelyRefused further 125 I-fibrinogen scans 0 1EPC removed after 1 da

33、y because of 1 equipment malfunction Total 4 5EPC = External pneumatic calf compressionResultsOne hundred sixteen patients were entered into the study protocol. Nine patients were excluded after randomization (five patients from the control group and four from the external pneumatic calf compression

34、 group). The specific reasons for exclusion are shown in Table 1. None of these patients subsequently developed deep venous thrombosis or pulmonary emboli. One hundred seven patients completed the study protocol, with 52 in the control group and 55 in the external pneumatic compression group.Table 2

35、. Age, Race, and Physical Findings of Patients in the Control and External Pneumatic Treatment GroupsTreatment group Externalpneumaticcalf com-Control pression(N = 52) (N = 55) Age (yr) 2O-29 3 l 30-39 2 5 40-49 9 8 50-59 10 17 60-69 19 16 70+ 9 8 Mean 58.2 56.1Race White 35 38 Black 16 14 Other 1 3

36、Physical findings Varicose veins Mild 7 12 Moderate 4 6 Severe 2 2 Venous stasis changes in legs 5 6 Mean weight (kg) 71.8 69.2Table 3. Organ Site and Clinical Stage of Malignancy in the Control and External Pneumatic Compression Treatment GroupsTreatment group External PneumaticControl Calf compres

37、sion (N = 52) (N = 55)Organ site Uterus 23 15 Ova ry 12 19 Cervix 12 18 Vulva 5 3Clinical stage Benign or intraepithelial 9 6 I 22 28 Il 4 7 III 13 7 IV 2 4 Recurrent 2 3Deep venous thrombosis and/or pulmonary embolus was diagnosed in 18 of 52 (34.6%) control group patients and in seven of 55 (12.7%

38、) external pneumatic compression patients (P .05) in the distribution of any parameter between the two study groups. These potential risk factors were further examined for their effects on the incidence of deep venous thrombosis and pulmonary emboli, both alone and in conjunction through the logisti

39、c regression analysis. Age over 60 (P .05), varicose veins (P .01), and advanced clinical stage of disease (P .05) were found to be independently associated with an increased incidence of venous thrombosis and pulmonary embolism (Table 6).Table 4. Current and Past Medical Problems and Current Medica

40、tions Used by Patients in Study GroupsTreatment groupExternal pneumatic Control calf compression Current or past medical problems History of deep vein thrombosis 2 4 History of pulmonary embolus 0 2 Hypertension 29 21 Diabetes mellitus 10 4 Congestive heart failure (compensated) 3 3 History of myoca

41、rdial infarct I 1Drugs Aspirin 23 30 Digoxin 3 4 Antihypertensive 24 20 Insulin 6 3 Estrogens or oral contraceptives 3 1The incidence of deep venous thrombosis and pulmonary embolism related to various surgical procedures is shown in Table 7. When adjustment is made for other risk factors, no surgic

42、al procedure was more often associated with venous thrombosis or pulmonary embolism. External pneumatic compression resulted in a reduction in the incidence of deep venous thrombosis as compared with the control treatment, after adjustment for these important prognostic factors (P .005).The postoper

43、ative day on which the thromboembolic complication was diagnosed in the two study groups is shown in Figure 1. The median time of occurrence was postoperative day 3 in the control group and day 4 in the external pneumatic compression group. During the first five postoperative days, four of 55 extern

44、al pneumatic calf compression patients developed a thromboembolic complication (7.3 %), while during the same time period 13 of 52 control group patients (25%) suffered a thromboembolic complication (P .02). Of patients with no thromboembolic complication during the first five postoperative days, th

45、ree of 51 external pneumatic compression patients (5.9%) and five of 39 control group patients (12.8%) subsequently developed a thromboembolic complication (P = .08).No significant side effects from the external pneumatic compression equipment were found except for perspiration beneath the calf slee

46、ve.DiscussionVenous thromboembolic complications are one of the leading causes of morbidity and mortality following major surgical procedures. Their significance is even greater in groups of high-risk patients such as those undergoing surgery for pelvic malignancies. With the advent of sensitive non

47、invasive diagnostic methods such as 125 l-fibrinogen counting and impedance plethysmography, the natural history and incidence of deep venous thrombosis has been more clearly delineated. The incidence of deep venous thrombosis and pulmonary emboli in the 52 untreated control group patients of 35% is

48、 similar to a prior prospective study using 125 l-fibrinogen counting in 45 gynecologic oncology patients in Great Britain.24 However, the incidence of thromboembolism may vary with time, even in similar groups of patients. For example, a previous prospective randomized clinical trial from the authors institution found a 12% incidence of thromboembolic complications in 97 control patients undergoing similar surgery for gynecologic malignancies.7 The varying incidence of thromboembolism has also been repor