This article is more than 5 years old. Information may no longer be current.

Comparison of ACCP and AAOS Guidelines for VTE Prophylaxis After Total Hip and Total Knee Arthroplasty

Add topic to email alerts

Receive an email when new articles are posted on

Please provide your email address to receive an email when new articles are posted on .

Subscribe

Added to email alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

Back to Healio

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com.

Back to Healio

Abstract

Orthopedists have expressed concerns regarding the utility for and applicability to their practices of guidelines from the American College of Chest Physicians (ACCP) for thromboprophylaxis in the settings of total hip and total knee arthroplasty (THA and TKA, respectively). These concerns include the acceptance by the ACCP of venographically assessed asymptomatic deep venous thrombosis as a meaningful clinical trial endpoint and a potential underestimation by the ACCP of the true risk of major bleeding and wound complication in unselected patient populations outside carefully controlled clinical trials. Because symptomatic pulmonary embolism is rare after THA and TKA, the American Academy of Orthopaedic Surgeons has developed a clinical practice guideline focused on preventing this complication while minimizing the risk of bleeding due to pharmacologic prophylaxis. These guidelines are reviewed here.

Clinical guidelines have been devised for a variety of disorders to standardize and improve patient care. A clinical guideline addresses key clinical problems or questions, and has a defined evidence base and grading system. Guidelines are developed based on available medical literature. When no or insufficient data exist upon which a clearly evidence-based recommendation can be made, they develop through a consensus process involving experts in the field. A clinical guideline should also encourage and guide future clinical research.

A clinical guideline is not a protocol for patient care or a statement of dogma immune to disagreement or change. Nor is a guideline a substitute for sound clinical judgment. There are currently 3 clinical guidelines dealing with prophylaxis of venous thromboembolism (VTE) that affect orthopedic surgeons who perform total hip or total knee arthroplasty (THA and TKA, respectively): those from the American College of Chest Physicians (ACCP),¹ those from the Surgical Care Improvement Project (SCIP),² and most recently, those from the American Academy of Orthopaedic Surgeons (AAOS). This article describes and compares the ACCP evidence-based clinical practice guidelines on the prevention of VTE and the AAOS clinical practice guideline Prevention of Symptomatic Pulmonary Embolism in Patients Undergoing Total Hip or Knee Arthroplasty.³

ACCP Guidelines

Orthopedic surgeons who perform THA and TKA have been greatly affected by the ACCP guidelines for the prevention of deep venous thrombosis (DVT). The ACCP is an organization of 16,500 members drawn from the fields of pulmonology, critical care medicine, sleep medicine, cardiology, cardiothoracic surgery, pediatric pulmonology, and pediatric critical care medicine. The ACCP VTE guidelines first appeared in 1986, and the most recent (8th) edition was published in June 2008.¹ The SCIP guidelines are essentially based on the 2004 ACCP guidelines. DVT, detected by venography or ultrasonography, was the primary outcome measure (based on prevalence) in the development of these guidelines. The strongest recommendations are based on prospective randomized studies, with most of these comparing the efficacy and safety of 1 pharmacologic agent with another or with placebo. Few studies evaluated mechanical or multimodal (combined) prophylaxis. Surgical patients are categorized as “low,” “medium,” or “high” risk, but all THA and TKA patients are considered high risk, regardless of patient age, activity level, or comorbidities.

The 2008 ACCP guidelines contain general recommendations, warnings, and specific recommendations for elective hip and knee arthroplasty. The general recommendations include that a formal, active strategy that addresses prevention of VTE be developed for every hospital (grade 1A). Strategies to increase thromboprophylaxis adherence include implementing computer decision support systems (grade 1A) and using preprinted orders (grade 1B). Warnings include using appropriate caution when using anticoagulants in patients undergoing neuraxial anesthesia or analgesia, or deep peripheral nerve blocks (grade 1A).

For THA, the ACCP guidelines recommend routine use of 1 of the following (grade 1A): (1) the usual high-risk dose of low- molecular-weight heparin (LMWH) started 12 hours preoperatively or 12 to 24 hours postoperatively or, alternatively, half the high-risk dose started 4 to 6 hours postoperatively and then increasing to the usual high-risk dose the following day; (2) fondaparinux 2.5 mg started 6 to 24 hours postoperatively; or (3) adjusted-dose warfarin started preoperatively with a target international normalization rate of 2.5 (range, 2.0 to 3.0). However, for THA patients at high risk of bleeding (with the criteria for “high risk” not specified), the optimal use of mechanical thromboprophylaxis with intermittent pneumatic compression (IPC) or the venous foot pump was recommended (grade 1A).

For TKA, routine thromboprophylaxis with the same anticoagulants listed above received grade 1A recommendations. However, the use of IPC was recommended as an alternative to anticoagulants (grade 1B). For TKA patients at high risk of bleeding (again, with criteria for “high risk” not specified), the optimal use of mechanical prophylaxis with IPC (grade 1A) or venous foot pump (grade 1B) was recommended. For both hip and knee patients, the recommended duration of prophylaxis was at least 10 days (grade 1A), with extension up to 35 days for hip patients (grade 1A), with LMWH (grade 1A), warfarin (grade 1B), and fondaparinux (grade 1C). For knee patients, extension up to 35 days was not as highly recommended (grade 2B), with the same recommendations (grade 1C) for LMWH, warfarin, and fondaparinux.

Orthopedists’ Concerns With ACCP Guidelines

Orthopedic surgeons have voiced concerns over the ACCP guidelines, which emphasize prophylaxis with strong pharmacologic agents.⁴ Asymptomatic thrombi detected by venography or ultrasonography are, for the purposes of assessing efficacy of prophylaxis, considered in these guidelines to be as important an outcome as symptomatic thromboembolism. Only data from prospective randomized studies were used to make a grade 1A recommendation. Thus, a grade 1A recommendation could not be based on data from even large (>1000 patients) cohort studies. Because prospective randomized studies of pharmacologic agents include only carefully selected patients with few comorbidities, these guidelines may not be applicable to the wide spectrum of patients undergoing THA or TKA. The ACCP guidelines might underestimate the risks of bleeding complications and other adverse outcomes, such as prolonged wound drainage or deep infection, related to the use of anticoagulants.⁴

Symptomatic pulmonary embolism (PE) is relatively rare after THA or TKA. The 90-day rate of fatal PE was 0.22% after 44,785 TKAs and 0.15% after 27,000 TKAs in the Scottish Registry.⁵ In a review of more than 200,000 TKAs in a California database, the 90-day rate of symptomatic PE was 0.41%.⁶

The risk of serious bleeding complications has been described in a nonselected group of THA and TKA patients given the ACCP grade 1A-recommended 10-day course of LMWH.⁷ In this study of 290 patients, major bleeding occurred in 9% of patients, with 4.7% requiring readmission. Efficacy of this approach was also questioned, in that symptomatic DVT occurred in 3.8% of patients and nonfatal symptomatic PE occurred in 1.3%. A recent study showed that patients who return to the operating room within 30 days after TKA for evacuation of a postoperative hematoma are at significantly increased risk for development of deep infection or for requiring other major surgery.⁸

AAOS Guidelines

Rationale and Methodology

The primary concerns of orthopedic surgeons after THA and TKA are the prevention of fatal and nonfatal symptomatic PE and minimizing serious joint bleeding and wound drainage that adversely affect patient outcome. The AAOS formed a work group in 2006 to develop a consensus guideline for the prevention of symptomatic PE after THA and TKA.^3,9,10 The work group was composed of 8 members of the AAOS with known expertise in the field. The group consulted an evidence review team from the Center for Clinical Evidence Synthesis at Tufts New England Medical Center, which has assisted other medical specialty groups with the development of guidelines. The key goals were to determine the rates of fatal and symptomatic PE after THA and TKA with different interventions (aspirin, warfarin, LMWH, fondaparinux, and mechanical methods) and the rates of adverse events (bleeding or death) associated with these interventions. The evidence base, determined by consensus of the work group, included the medical literature meeting certain strict criteria: (1) a prospective study of hip or knee arthroplasties performed since 1996 only; (2) a cohort study with at least 100 patients per group; or (3) a randomized controlled trial with at least 10 patients per treatment group.¹⁰ There were no recent studies including at least 1000 patient of the natural history of PE occurring in the absence of thromboprophylaxis. Older studies were excluded, because the work group concluded that techniques and postoperative rehabilitation had greatly changed over the past 2 decades.

The literature review included 2713 citations from search engines and 10 other articles of which the work group was aware but that had not been retrieved by searches of electronic databases.¹⁰ Of these 2723 citations, only 42 articles met the specified criteria. Of the 42 articles, 26 with cohorts totaling 16,304 THAs and 16 with cohorts totaling 11,665 TKAs were reviewed by the evidence review team. The individual studies were graded from I to V according to level of evidence (Table 1). The strength of recommendation was graded A to C based on the quality of the studies upon which the recommendation was based (Table 2). The studies reviewed were heterogeneous in many ways, including treatment doses, intensity and timing of treatment, cotreatments, and anesthetic techniques.

The results of the literature review were presented as a series of forest plots for THA and TKA.^3,9,10 These include all PE, fatal PE, and all deaths after THA or TKA, as well as major bleeding and death related to bleeding after THA or TKA.^3,9,10 Conclusions and summary recommendations applied to both THA and TKA.

The rate of fatal PE was approximately 1 per 1700 arthroplasties, and there were no differences among prophylactic methods. The rate of nonfatal PE was approximately 1 per 300 arthroplasties with any prophylactic method. The rate of death from bleeding was approximately 1 per 3000 arthroplasties. Major bleeding complications were more common in patients treated with systemic pharmacologic prophylaxis (random effects model [REM] summary estimate, 1.8%; 95% CI, 1.4%-2.5%) than in those treated with mechanical prophylaxis and aspirin (REM summary estimate, 0.14%; 95% CI, 0.03%-0.8%). Literature review was complicated by clinical heterogeneity and interstudy differences in outcome measures and sample sizes.

Recommendations

The AAOS guideline recommendations are derived from both the work group consensus process and the literature review and analysis process. The guideline is meant to be followed in its entirety, rather than selectively implemented. From the work group consensus process, there are 9 recommendations (Table 3). Most important are (1) the preoperative evaluation of the patient by the orthopedic surgeon to assess whether the risk for PE is standard or elevated (grade IIIB) and (2) whether the risk of bleeding is standard or elevated (grade IIIC). Another recommendation is that the patient and surgeon should consider (in consultation with the anesthesiologist) the use of regional anesthesia (grade IVC). The surgeon should consider using mechanical prophylaxis intraoperatively or immediately postoperatively (grade IIIB) and continue it until patient discharge (grade IVC).

The AAOS guideline recommendations for postoperative medication were derived from the literature review and analysis. These recommendations are stratified into 4 groups based on the preoperative assessment of the risk for both PE and major bleeding (Table 4).

Discussion

The literature review and analysis by the work group for the AAOS clinical guideline for preventing PE following THA or TKA showed no important differences among the different thromboembolism prophylactic methods in terms of rate of all PE, fatal PE, all death, or death from bleeding. The rate of major bleeding was very low with the combined intervention of mechanical prophylaxis and aspirin compared with that associated with other pharmacologic interventions. Orthopedic surgeons should evaluate and carefully document preoperatively each patient’s risk for PE and major bleeding. Examples of patients who may be at elevated risk for PE are those with previous symptomatic thromboembolism, especially PE; those with known heritable thrombophilia or hypercoagulable state (protein C or S deficiency); and those who cannot ambulate rapidly after surgery. Examples of patients who may be at a higher risk for bleeding are those having revision knee arthroplasty or primary arthroplasty with extensive releases and those with a history of a bleeding disorder or of bleeding in other locations (eg, gastrointestinal or intracranial).¹⁰ The orthopedic surgeon should consider the patient-specific risk:benefit ratio before prescribing any pharmacologic intervention.

Some data in the literature support preoperative risk assessment and multimodal thromboprophylaxis, the cornerstone of the AAOS guidelines. Lotke and Lonner reported the results of 3473 total knee arthroplasties treated with foot pumps and aspirin.¹¹ High-risk patients identified preoperatively were excluded and given warfarin prophylaxis. With multimodal prophylaxis, the rate of nonfatal PE was 0.26% and the rate of fatal PE was 0.06%-0.14%. Dorr et al reported preoperative assessment and use of calf compression and aspirin in 1179 total hip and knee arthroplasty patients, with no fatal PEs and a 0.25% incidence of nonfatal PE.¹² Lachiewicz and Soileau reported a 0.5% incidence of nonfatal PE in 856 TKAs given mechanical calf vein compression and aspirin.¹³ Westrich et al reported incidences of fatal and nonfatal PE of 0.04% and 1%, respectively, in 2592 THAs,¹⁴ whereas Lachiewicz and Soileau reported incidences of 0.09% and 0.7%.¹⁵ Both of these studies used multimodal prophylaxis with IPC and aspirin.

The AAOS guideline has encountered some criticism. In a commentary by Eikelboom et al supporting the use of the ACCP guidelines for hip and knee arthroplasty patients, the use of asymptomatic DVT as a valid surrogate outcome measure for PE was defended.¹⁶ There are some nonarthroplasty studies that show a parallel reduction in incidence of DVT and PE when antithrombotic agents are compared with placebo or no treatment. However, the position of the AAOS remains that there is insufficient evidence to conclude that in THA and TKA, asymptomatic DVT meets the criterion of a valid surrogate endpoint. The impact of the harm of treatment, especially bleeding, was also not addressed in that commentary.

The AAOS work group encourages future prospective, randomized, multicenter studies comparing the various interventions presently in use, as well as new pharmacologic agents, with the outcome measures of symptomatic PE and major bleeding. The AAOS plans a new work group to review the guideline at regular intervals in the future.

References

1. Geerts WH, Bergqvist D, Pineo GF, et al. Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. 2008; 133(suppl 6):381S-453S.
2. Surgical Care Improvement Project (SCIP). http://scalpel.stanford.edu/2007-2008/SCIPeducationalTool2007v4.pdf. Accessed September 15, 2009.
3. Johanson NA, Lachiewicz PF, Lieberman JR, et al. Prevention of symptomatic pulmonary embolism in patients undergoing total hip or knee arthroplasty. J Am Acad Orthop Surg. 2009; 17(3):183-196.
4. Callaghan JJ, Dorr LD, Engh GA, et al; American College of Chest Physicians. Prophylaxis for thromboembolic disease: Recommendations from the American College of Chest Physicians – are they appropriate for orthopaedic surgery [editorial]? J Arthroplasty. 2005: 20(3):273-274.
5. Howie C, Hughes H, Watts AC. Venous thromboembolism associated with hip and knee replacement over a ten-year period: a population-based study. J Bone Joint Surg Br. 2005: 87(12):1675-1680.
6. SooHoo NF, Lieberman JR, Ko CY, Zingmond DS. Factors predicting complication rates following total knee replacement. J Bone Joint Surg Am. 2006; 88(3):480-485.
7. Burnett RS, Clohisy JC, Wright RW, et al. Failure of the American College of Chest Physicians-1A protocol for Lovenox in clinical outcomes for thromboembolic prophylaxis. J Arthroplasty. 2007; 22(3):317-324.
8. Galat DD, McGovern SC, Hanssen AD, Larson DR, Harrington JR, Clarke HD. Early return to surgery for evacuation of a postoperative hematoma after primary total knee arthroplasty. J Bone Joint Surg Am. 2008; 90(11):2331-2336.
9. Haas SB, Barrack RL, Westrich G, Lachiewicz PF. Venous thromboembolic disease after total hip and knee arthroplasty. J Bone Joint Surg Am. 2008; 90(12):2764-2780.
10. Lachiewicz PF. Prevention of symptomatic pulmonary embolism in patients undergoing total hip and knee arthroplasty: clinical guideline of the American Academy of Orthopaedic Surgeons. In: Azar F, O’Connor M, eds. Instructional Course Lectures. Vol 58. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2009:795-804.
11. Lotke PA, Lonner JH. The benefit of aspirin chemoprophylaxis for thromboembolism prophylaxis after total knee arthroplasty. Clin Orthop Relat Res. 2006; (452):175-180.
12. Dorr LD, Gendelman V, Maheshwari AV, Boutary M, Wan Z, Long WT. Multimodal thromboprophylaxis for total hip and knee arthroplasty based on risk assessment. J Bone Joint Surg Am. 2007; 89(12):2648-2657.
13. Lachiewicz PF, Soileau ES. Mechanical calf compression and aspirin prophylaxis for total knee arthroplasty. Clin Orthop Relat Res. 2007; (464):61-64.
14. Westrich GH, Farrell C, Bono JV, Ranawat CS, Salvati EA, Sculco TP. The incidence of venous thromboembolism after total hip arthroplasty: a specific hypotensive anesthesia protocol. J Arthroplasty. 1999; 14(4):456-463.
15. Lachiewicz PF, Soileau ES. Multimodal prophylaxis for THA with mechanical compression. Clin Orthop Relat Res. 2006; (453):225-230.
16. Eikelboom JW, Karthikeyan G, Fagel N, Hirsch J. American Association of Orthopedic Surgeons and American College of Chest Physicians guidelines for venous thromboembolism prevention in hip and knee arthroplasty differ. Chest. 2009; 135(2):513-520.

Author

Dr Lachiewicz is from the Department of Surgery, Section of Orthopaedic Surgery, Duke University Medical Center and Durham VA Medical Center, Durham, and is also from Durham Regional Medical Center, Durham, and Chapel Hill Orthopedics Surgery & Sports Medicine, Chapel Hill, North Carolina.

Dr Lachiewicz is on the speaker’s bureau and is a consultant for DJO Global and Zimmer, and is a consultant for Covidien.

Correspondence should be addressed to: Paul F. Lachiewicz, MD, 101 Conner Dr, Ste 200, Chapel Hill, NC 27514.

doi: 10.3928/01477447-20091103-52