IPC預防靜脈栓

1、IPC預防靜脈栓Intermittent Pneumatic Compression for the Prevention of Venous Thromboembolism1-4Intermittent pneumatic leg compression is an effective method for preventing postoperative deep vein thrombosis. Because deep vein thrombosis is the pre-cursor for pulmonary embolism, it has been assumed that t

2、his widely used modality is effective in reducing the frequency of fatal and nonfatal pulmonary embolism. Administration of low dose subcutaneous heparin is also an effective method for preventing postoperative deep vein thrombosis and historically has been the most widely used prophylactic approach

3、5-7 Unlike intermittent pneumatic leg compression, for low dose heparin prophylaxis there is direct evidence that this pharmacologic approach significantly reduces fatal pulmonary embolism,8 Few studies, however, have used objectively diagnosed pulmonary embolism as the primary outcome event. The us

4、e of intermittent pneumatic leg compression perioperatively and postoperatively to reduce file frequencies of thromboembolic complications is based on a sound physiologic rationale. The prevention of venous thrombosis is likely associated with the observation that the achievement of high flow pulsal

5、ity empties the deep veins periodically, thus overcoming venous stasis.9,10 Furthermore, there is evidence that physiologic effects are achieved, such as enhanced fibrinolysis,11 Thus, intermittent pneumatic compression affects Virchow's triad in two of the three domains, ie, decreased stasis an

6、d altered coagulation.9-11 Intermittent pneumatic compression has been studied in a broad spectrum of patients and has been shown to be both effective and safe. 12-25 The patient populations studied had experienced a variety, of surgical procedures-general surgery,12-14 gynecology,15 neurosurgery, 1

7、6,17 orthopedics,l8-24 and urology25 Com-pared with no prophylaxis, intermittent compression dearly is effective in reducing distal deep vein thrombosis. Where bilateral venography is used to define the end point, intermittent pneumatic compression also reduces the incidence of proximal deep vein th

8、rombosis. Intermittent pneumatic compression is especially useful in patients at high risk of bleeding complications, such as in neurosurgery and pelvic cancer surgery, or in situations where pharmacologic agents are contraindicated, as in multiple trauma. On the other hand, intermittent pneumatic c

9、ompression devices are somewhat cumbersome and inconvenient, potentially leading to less than optimal compliance rates by patients and nursing staff. The cumbersome nature of these devices has been over-come by the more modern versions. There are certain situations where the devices cannot be applie

10、d, such as in patients with lower leg fractures. It is clear that prevention of venous thrombosis is more cost-effective than either secondary prophylaxis or treating thrombotic complications when they occur. Studies comparing the cost-effectiveness of intermit- tent pneumatic compression and other

11、alternative methods of preventing venous thrombosis after general surgery or orthopedic surgery have indicated thatintermittent pneumatic compression alone or with graduated compression stockings represents a cost-effective approach. Recently, foot pulsatile devices have been shown to be effective i

12、n preventing venous thrombosis after total hip replacement when compared with either placebo or low dose heparin. These devices have the advantage of not interfering as much with the opera-rive site, particularly in patients undergoing joint replacement surgery. Further, large scale Studies with the

13、se devices are awaited with interest. Combined modalities have been used in patients at high risk of venous thrombosis in an attempt to decrease thrombosis rates, Thus, low dose heparin has been combined with dihydroxyergotamine, or graduated compression stockings;aa-as low molecular weight heparin

14、has been combined with graduated compression stockings;aa and intermittent pneumatic compression has been combined with graduated compression stockings; The number of patients in these studies has been rather small, but some have demonstrated a significant difference of combined modalities over sing

15、le approaches. A cost analysis study demonstrated that the combination of intermittent pneumatic compression or low dose heparin with graduated compression stockings achieved greater cost savings in the prevention of thromboembolism in both general and orthopedic surgery than the single modalities b

16、y themselves.3s In this issue of CHEST (see page 82), Ramos and colleagues expand our understanding of thromboprophylaxis in their report of the role of combined mechanical and pharmacologic prophylaxis in cardiac surgery patients. In an open randomized trial of 2,786 patients undergoing open heart

17、surgery who received either combined prophylaxis with pneumatic compression stockings and low. dose subcutaneous heparin or low dose subcutaneous heparin alone, they objectively assessed the frequency of pulmonary embolic complications. They observed a frequency of pulmonary embolism of 1.5% in the

18、combined prophylaxis group vs 4% in the low dose heparin alone group. They concluded that "these data suggest that the combined prophylactic method of bilateral pneumatic compression stockings and subcutaneous heparin is superior to subcutaneous heparin alone in the prevention of pulmonary embo

19、lism after cardiac surgery." By necessity, this randomized trial could not be double-blinded, thereby introducing the possibility of a diagnostic suspicion bias which may have biased the frequencies of pulmonary embolism in their study groups. This bias probably did not occur because these inve

20、stigators systematically used the same criteria to suspect and identify the presence of pulmonary embolism. Importantly, outcome assessment of the frequency of pulmonary embolism was achieved by objective documentation. An important methodologic issue is the need for outcome interpretation to be per

21、formed independently and without knowledge of the patient's treatment group. The authors were not specific in this regard; lack of blind interpretation could have been an important confounder due to bias in outcome assessment. Another methodologic issue is thehigher exclusion rate in the low-dos

22、e heparin arm (13% vs 4%). Because this potential bias may have re-suited in a lower pulmonary embolism rate in the low dose heparin arm, this potential confounder is a biasagainst, rather than for, the observed difference in favor of combined intermittent pneumatic compression and low dose subcutan

23、eous heparin. Data on potential cointervention and contamination (eg, aspirin use) are not provided by the authors. Standard clinical practice in patients undergoing open cardiac surgery likely re-suited in similar rates of cointervention and contamination in each arm. Randomizatioh was effective as

24、 the clinical characteristics and demographics were similar in each arm. Thus, the observed difference in the frequencies of pulmonary embolism cannot be explained by differences in the patients' characteristics on entry into the study. Accordingly, the authors' observation that "the co

25、ncomitant use of bilateral pneumatic compression stockings and subcutaneous heparin reduced the frequency of postoperative pulmonary embolism by 62% in comparison to the prophylaxis with subcutaneous heparin alone (p<0.001)" likely stands. It is reasonable to continue using intermittent pneu

26、matic leg compression based on the inference that clinically important pulmonary embolism is reduced by this modality. This inference is strengthened by the findings of Ramos and colleagues in this issue, where the primary outcome measure is pulmonary embolism as distinct from venous thrombosis. The

27、 hope that combined modalities would be more effective than single approaches alone is supported by their data. Thus, there is now more substantive empiric evidence for combining specifically intermittent pneumatic leg compression with subcutaneous heparin. This will en-courage the pursuit of other

28、studies using combined modalities in high risk groups such as patients under-going knee arthroplasties who, despite effective single methods of prophylaxis, have disappointingly high rates of deep vein thrombosis. The cost-effectiveness of combined modalities and the need for continued prophylaxis f

29、ollowing discharge require further study. 7 The availability of these devices is limited in many centers, potentially denying many patients this approach to prophylaxis. The evidence to date indicates that intermittent pneumatic compression should be widely available for prophylaxis of deep vein thr

30、ombosis, particularly in high risk patients. Russell D. Hull, MBBS, FCCP Graham F. Pineo, MD, FCCP Calgary, Alberta, CanadaFrom the Foothills Hospital (Dr. Hull), and Calgary General Hospital (Dr. Pineo). Drs. Hull and Pineo are both Professors of Medmine at the University of Calgary. REFERENCES 1 M

31、ayor GE, Galloway JMD. The iliofemoral venous segment as a source of pulmonary emboli. Lancet 1967; 1:871-74 2 Kakkar VV, Flanc C, Howe CT, et al. Natural history of post-op-erative deep-vein thrombosis. Lancet 1969; 2:230-33 3 Moser KM, Le Moine JR. Is embolic risk conditioned by location of deep v

32、enom thrombosis? Ann Intern Med 1981; 94:439-44 4 Huisman MV, Buller HR, ten Cate JW, et al. Unexpected high prevalence of silent pulmonary embolism in patients with deep venous thrombosis. Chest 1989; 95:498-502 5 Clagett GP, Reisch JS. Prevention of venous thromboembolism in general surgical patie

33、nts: results of meta-analysis. Ann Surg 1988; 208:22740 6 Collins R, Scrimgeour A, Yusef S, et al. Reduction in fatal pulmonary embolism and venous thrombosis by perioperative administration of subcutaneous heparin. N Engl J Med 1988; 318:1162-73 7 Nicolaides AN, Arcelus J, Belearo G, et al. Prevent

34、ion of venous thromboembolism. Int Angiol 1992; 11:151-58 8 International Multicentre Trial. Prevention of fatal postoperative pulmonary embolism by low closes of heparin. Lancet 1975;2:45-64 9 Meyerowitz B, Nelson R. Measurement of the velocity of blood in lower limb veins with and without compress

35、ion. Surgery 1964; 56:481-8610 Caprini J, Chueker j, Zuckerman L, et al. Thrombosis prophylaxis using external compression. Surg Gynecol Obstet 1983; 156:59,9-60411 Guyton DP, Khayat A, Sehereiber 1f. Pneumatic compression stockings and prostaglandin synthesis: a pathway of fibrinolysis? Crit Care M

36、ed 1985; 13:266-7012 Nicolaides AN, Femandes e Femandes J, Pollock AV. Intermit-tent sequential pneumatic compression of the legs in the pre-vention of venous stasis and postoperative deep venous throm- bosis. Surgery 1980; 87:69-7613 Nicolaides AN, Miles C, Hoare M, et al. Intennittent sequential p

37、neumatic compression of the legs and thromboembolism-deterrent stockings in the prevention of postoperative deep vein thrombosis. Surgery 1983; 94:21-514 Smith RC, Elton BA, Orr JD, et al. Dextran and intermittent pneumatic compression in prevention of postoperative deep vein thrombosis: inultiunit

38、trial. BMJ 1978; 1:952-5415 Clarke-Pearson D, Synan IS, Hinshaw WM, et al. Prevention of postoperative venous thmmbocmbolism by extemal pneumaticcalf compression in patients with gynecologic malignancy. Surg Gynecol Obstet 1984; 63:92-816 Skilhnan jj, Collins RR, Coe NP, et al. Prevention of deep ve

39、in thrombosis in neurosurgieal patients: a controlled, randomized trial of external pneumatic commpression boots. Surgery 1978; 83:354-5817 Turpie AG, Delmore T, Ilirsh J, et al. Prevention of venous thrombosis by intermittent sequential calf compression in pa-tients with intracranial disease. Throm

40、b Res 1979; 16:611-1618 Hull RD, Delmore TJ, Hirsh J, et itl. Effectiveness of intermit-tent pulsatile elastic stockings for the prevention of calf mid thigh vein thrombosis in patients undergoing elective knee surgery. Thromb Res 1979; 16:374519 Mekenna R, Galante J, Baehmann F, et al. Prevention o

41、f venous thromboembolism after total knee replacement by high-dose as-pirin or intermittent calf and thigh compression. BMJ 1980; 1:514-1720 Gallus A, Raman K, Darby T. Venous thromboembolism after elective hip replacement: the influence of preventive intermittent calf compression and of surgical te

42、chnique. Br J sting 1983; 70:17-921 Hull RD, Raskob G, Gent M, et al. Effectiveness of intermittent pneumatic leg compression for preventing deep vein thrombosis after total hip replacement. JAMA 1990; 263:2313-1722 Paiement F, Wessinger SJ, Waltman WC, et al. Ix)w-dose war-farin versus external pne

43、umatic compression for prophylaxis against venous thromboembolism following total hip replace- ment. J Arthroplasty 1987; 2:23-623 Francis CW, Pellegrini VD, Marder vJ, et al. Compaison of warfarin and external pneumatic compression in prevention of venous thrombosis after total hip replacement JAMA

44、 1992; 267:2911-1524 Kaempffe FA, Lifeso RM, Meinking C. Intermittent pneumatic compression versus Coumadin: prevention of deep vein Throm-bosis in lower-extremity total joint arthroplasty. Clin Orthop 1991; 269:89-9725 Coc NP, Collins REC, Klein LA, et al. Prevention of deep vein thrombosis in urol

45、ogical patients: a controlled, randomised trial of low dose heparin and external pneumatic compression boots. Surgery 1978; 83:354-5826 Colditz GA, Tuden RL, Oster G. Rates of venous thrombosis af-ter general surgery: combined results of randomised cliniCtl tri-als. Lancet 1986; 2:1434627 Oster G, T

46、uden RL, Colditz GA. A cest-effectiveness analysis of prophylaxis against deep vein throlnbosis in major orthopedic surgery. JAMA 1987; 257:203-0828 Bradley JG, Kmgener CH, Jager itj. The effectiveness of inter mittent plantar venous compression in prevention of deep venous thrombosis after total hi

47、p arthroplasty, j Arthroplasb, 1993;8:57-6129 Santori FS, Vitullo A, Stopponi M, et al. Prophylaxis against deep-vein thrombosis in total hip replacement. J Bone Joint Surg 1994; 76:579-8330 Fordyee MJF, Ling RSM. A venous foot pump reduces throm-bosis after total hip replacement. J Bone Joint Surg 1992; 74:45-9 31 Nicolaides AN, Kalodiki E. The contribution of colour flow im-aging to postoperative su