- Email: [email protected]
Risk level analysis for deep vein thrombosis (DVT): A study of Turkish patients undergoing major orthopedic surgery
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SEPTEMBER 2015
Risk level analysis for deep vein thrombosis (DVT): A study of Turkish patients undergoing major orthopedic surgery Funda B€ uy€ ukyılmaz, PhD, BSN, Merdiye S¸endir, PhD, BSN, Ricky Autar, DiPN, PhD, MSc, BA (HONS), _ and Ilknur Yazgan, MSc, RN
Deep vein thrombosis (DVT) is a prevalent problem for orthopedic patients, particularly owing to the nature of operative interventions and treatment procedures, predisposing to an high risk of DVT. This descriptive study was conducted to determine the levels of risk, the risk factors, and their odds ratio for DVT in patients undergoing major orthopedic surgery. Data were collected using a Patient Information Form and the Autar DVT Risk Assessment Scale (DVTRAS) in orthopedic wards of a university hospital on postoperative day 2. Data were analyzed using descriptive, comparative analysis, and binary logistic regression. The 102 patients (mean age, 52.58 21.58 years) were hospitalized for a mean of 14.35 14.56. Of the sample, 53.9% were female, 65.7% had a history of previous surgery, and 54.9% had undergone total hip/knee arthroplastic surgery, 67.6% of patients wore graduated compression stockings, and 62.7% were administered liquid infusion. Those patients had moderate risk score (12.77 5.66) in the Autar DVTRAS. According to binary logistic regression analysis, aging, obesity, immobility, and acute and chronic diseases were significant risk factors for postoperative DVT (p # .05). This study highlights evidence on the degree of DVT risk, risk factors, and impact of venous thromboembolism in patients undergoing major orthopedic operations. For evidence-based clinical practice, these high-level risk factors should be taken into account in the prevention of DVT in orthopedic patients. (J Vasc Nurs 2015;33:100-105)
Deep vein thrombosis (DVT) and venous thromboembolism (VTE) are serious causes of patient morbidity and mortality in hospitalized patients. VTE comprises DVT and pulmonary embolism, which results when a blood clot is formed in the deep veins (usually in the lower legs) and some or all of a clot detaches and travels to the lungs; this is a potentially fatal condition.1–4 The formation of a DVT can be owing to 1 or a combination of 3 predisposing factors, known as Virchow’s triad—vessel trauma, venous stasis, and hypercoagulability.5 From the Florence Nightingale Faculty of Nursing, Istanbul University, Istanbul, Turkey; Faculty of Health and Life Sciences, De Montfort University, Leicester, UK; Orthopedic and Traumatology Department, Istanbul Medical Faculty Hospital, Istanbul University, Istanbul, Turkey. Corresponding author: Funda B€uy€ukyılmaz, PhD, BSN, Assistant Professor, Fundamental of Nursing Department, Istanbul University Florence Nightingale Faculty of Nursing, 34381 _ S¸is¸li-Istanbul/Turkey. Tel.: +90 212 440 00 00 (27126); Fax: +90 212 224 49 90. (E-mails: fundabuyukyilmaz@hotmail. com, [email protected]). Conflicts of interest: The authors confirm that there are no financial or personal relationships with other people or organizations that inappropriately influenced this work. 1062-0303/$36.00 Copyright Ó 2015 by the Society for Vascular Nursing, Inc. http://dx.doi.org/10.1016/j.jvn.2015.01.004
DVT is a most prevalent problem for orthopedic patients, particularly owing to the nature of operative interventions and treatment procedures, predisposing to an high risk for DVT. In the postoperative period, the incidence of DVT is affected by preexisting factors such as surgical orthopedic procedures, the existence of infection, and the level of mobility.6–9 Major surgery and especially undergoing major orthopedic surgery (such as total hip arthroplasty, total knee arthroplasty, hip fracture surgery, spinal cord injury, and major trauma) confer the greatest risk for DVT because of postoperative immobility and the surgical trauma on the coagulation system inflicted by direct trauma to deep veins, and marked venous stasis subsequent to these procedures.10–13 Anderson and Spencer14 postulated that patients who underwent major orthopedic surgery had a moderate risk for DVT. Additional factors increasing the risk of DVT have also been identified, such as prior DVT history, myocardial infarction, congestive heart or respiratory failure, aging, obesity, and immobility.8,15,16 Similarly, a study by Bagaria et al17 established that the contributing risk factors found to be significantly responsible for the development of DVT were prolonged operation ($2 hours), prolonged immobility ($72 hours), and larger build/body mass index (BMI). In another study, Deitelzweig et al13 claimed that, for patients undergoing orthopedic surgery, DVT risk levels (low, moderate, high, and highest) may be increased by advancing age; other risk factors for DVT include current surgery and immobilization duration. Risk factors are additive and the more risk factors exist, the greater is the risk of DVT. For example, elderly female patients undergoing major
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Figure 1. Autar Deep Vein Thrombosis Risk Assessment Scale (2002).
orthopedic surgery on complete bed rest in the postoperative period are more prone to DVT/fatal pulmonary embolism.7,18 In this context, the National Institutes for Health and Care Excellence19 guidelines emphasized that DVT risk level determination is an essential strategy for the implementation of appropriate care for patients perioperatively. It is therefore imperative that health care providers routinely assess their patients’ DVT risk using the tools that have been developed and tested.1,2,11,15 After this, health care providers must plan and implement prophylactic interventions according to the patients’ risk assessment score and calculate their risk factors odds ratio for DVT.8,15,20 The purpose of this study was to determine the levels of risk, the risk factors, and their odds ratio for DVT in patients undergoing major orthopedic surgery. The research questions were:
What are the patients’ levels of risk for DVT? What are the risk factors for DVT in patients undergoing major orthopedic surgery?
What are the odds ratio effect of the risk factors on patients undergoing major orthopedic surgery? MATERIAL AND METHODS
Design, sample, and criteria for participation This descriptive study was conducted in the orthopedic wards of a university hospital in Turkey between January 2010 and 2011. The study sample consisted of 102 patients who met the inclusion criteria and agreed to participate in the study. The following inclusion and exclusion criteria were applied. Patients who were 18 years or older, mentally lucid enough to answer questions, hospitalized for a major operative procedure (total hip or knee arthroplasty, osteosarcoma, or hemiarthroplasty). They would also be the recipient of same prophylactic procedures during the postoperative period (enoxaparin via subcutaneous administration), graduated compression stockings and early ambulation 24–48 hours postoperatively with stockings,
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were admitted to the study. Those with cognitive, affective, and verbal impairment, and another acute illness causing DVT and the development of any complications during the perioperative period were excluded.
Ethical considerations Ethical considerations were duly applied and the ethics committee of the university hospital approved this study. Patients were informed orally of the purpose of the study, and informed consent was sought by the researchers. Potential respondents who met the inclusion criteria and willing were given oral and written information by the researchers regarding the aim of the study, assurance of anonymity and confidentiality, and the right to refuse to participate. No identifiable data were collected.
Data collection instruments A patient information form and the Autar DVT Risk Assessment Scale (Autar DVTRAS) were used on patients on the morning of second postoperative day to assess their risk of DVT. For the purpose of consistency, these instruments were administered for 2–3 minutes by 1 researcher to all of the participants in face-to-face interviews in the patients’ rooms.
The patient information form The patient information form was developed by the researchers based on a literature review and included questions on sociodemographics, previous surgical history, types of current surgery, and implementing interventions about DVT during the hospitalization period.8,11,20–22
The Autar DVTRAS The Autar DVTRAS was designed to determine the patients’ risk of DVT. It consists of subscales, such as age group, BMI, mobility, special risk category, trauma risk category, surgical intervention, and current high-risk diseases (Figure 1). Within each section, subcategories are arranged generally in ascending numerical order to provide an overall picture of a higher score representing increased risk of DVT. The total score obtained from the Autar DVTRAS results in the following risk categories for DVT: high ($15), moderate (11-14), low (7-10), or no risk (#6).21,22 The original scale was developed by Autar (1994) and revised by the author in 2003. Autar (2003) calculated the Cronbach a value to be 0.88-0.95.22
Reliability and validity study for Turkish version of the Autar DVTRAS The researchers first obtained written permission from Dr. Ricky Autar to adapt the Autar DVTRAS for a Turkish version. A reliability and validity study for the Turkish version of Autar DVTRAS was conducted by authors. To ensure the quality of the Turkish Autar DVTRAS, an internationally accepted forwardback-translation technique was used to translate the English version of the Autar DVTRAS to a Turkish equivalent of the original instrument. Then, Turkish language equivalence of the scale reliability and validity analysis was provided. Reliability was assessed by measuring the stability, equivalence, and internal consistency of this instrument. The Autar DVTRAS was a stable instrument over the passage of time (rS = 0.78; p # .001). Inter-rater reliability
SEPTEMBER 2015
TABLE 1 PATIENT CHARACTERISTICS (N = 102) Characteristic Gender Female Male Educational level Read and write Primary school High school University Marital status Single Married Divorced/widowed Previous surgery history Yes No Type of surgery Total hip/knee arthroplasty Hemiarthroplasty Vertebrae reconstruction Tumor resection
n
%
55 47
53.9 46.1
17 45 22 18
16.7 44.1 21.6 17.6
27 49 26
26.5 48.0 25.5
67 35
65.7 34.3
56 30 8 8
55.0 29.4 7.8 7.8
demonstrated the equivalence of Autar DVTRAS when different raters used the instrument to assess individual’s risk of developing DVT. There were no differences in the Autar DVTRAS scores obtained by the 2 separate raters (p # .001). Internal consistency reliability by Cronbach a coefficient for the Autar DVTRAS was 0.62-0.67, which indicates that the tool was homogenous. For content validity, a panel of professional experts (10 orthopedists, 10 physiotherapists, 10 nurses, and 10 nurse faculty members) assessed the content and clarity of the items in detail. Construct validity was established by contrasting patients with DVT and non- DVT subjects (N = 84). The Autar DVTRAS was able to differentiate between those who were expected to be at high risk of DVT risk and those who were expected to be low risk for DVT. The Autar DVTRAS was administered by 1 researcher to patients who agreed to participate. In the present study, the Cronbach a statistical value was calculated to be 0.78-0.90.
Data analysis Data were analyzed using the Statistical Package for Social Science for Windows (SPSS) version 21.0 (IBM Corp., Armonk, NY). Descriptive statistics were computed. A binary logistic regression model with a backward stepwise procedure was performed in order to identify the risk factors associated with DVT risk scores in the postoperative period. In this study, a p < .05 was considered significant.
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TABLE 3 EFFECT OF PATIENTS’ AUTAR DEEP VEIN THROMBOSIS RISK ASSESSMENT SUBSCALE CHARACTERISTICS ON THEIR MEAN SCORES (N = 102) Subscale characteristics Figure 2. Preventive interventions toward deep vein thrombosis (DVT) during the hospitalization period*. *More than 1 preventive interventions were implemented.
TABLE 2 MEAN SCORES OF AUTAR DEEP VEIN THROMBOSIS RISK ASSESSMENT SCALE Variables
Min-Max
Age groups Body mass index Mobility Special risk category Trauma risk category Surgical intervention Current high-risk diseases Total score
0-5 0-4 0-4 0-3 0-7 2-4 0-5 2-23
Mean SD 2.67 1.53 1.81 0.24 2.30 3.10 1.16 12.77
1.96 0.98 1.47 0.66 1.96 0.91 1.72 5.66
RESULTS Patient characteristics are provided in Table 1. In addition, 67.6% of patients wore graduated compression stockings, and 62.7% were administered liquid infusion to prevent DVT from dehydration during the hospitalization period (14.35 14.56 days; Figure 2). The mean scores and standard deviations for patients’ DVT risk levels are provided in Table 2. The patients’ subscale characteristics are shown in Table 3. In addition, according to binary logistic regression analysis, patients in the 31-50, 51-70, and $71 years age groups had 23.49 times, 10.02 times, and 20.49 times, respectively, higher postoperative DVT risk than those in the 18-30 years age group. The patients who exhibited an overweight/obese BMI (odds ratio [OR], 13.51), had very limited to complete bed rest mobility level (OR, 35.50), trauma risk in the preoperative period (especially pelvic and lower limb injury; OR, 110.58), or current high-risk diseases (especially chronic heart disease; OR, 2237.15) with a high postoperative DVT risk (Table 4).
DISCUSSION The focus of this study was to identify the level of DVT risk, risk factors, and their effects on postoperative DVT scores in patients undergoing major orthopedic operations. The literature
n
%
Age-specific group (years) 18-30 23 22.5 31-50 23 22.5 51-70 27 26.5 $71 29 28.5 (mean SD = 52.58 21.58) Build/body mass index Average/desirable 60 58.8 Overweight/Obese 42 41.2 Mobility Limited 53 52.0 Very limited/ 49 48.0 complete bed rest Special risk category Oral contraceptives 93 91.2 Hormone 9 8.8 replacement therapy Trauma risk category (preoperative period) Yes 62 60.8 No 40 39.2 Surgical intervention Planned major 84 82.4 surgery Emergency major 18 17.6 surgery Current high-risk diseases Yes 34 33.3 No 68 66.7
DVT (Mean SD)
6.83 10.52 13.93 18.21
3.17 3.07 4.79 3.74
11.46 5.02 15.86 5.00 10.50 4.08 16.24 4.82
12.45 5.52 14.14 5.76
15.68 4.68 8.28 3.83 12.54 5.62 13.89 5.88
18.47 4.06 9.93 4.06
showed that, although all hospitalized patients had the potential to develop DVT, certain factors increase this risk.22–24 In a large study of 18,461 patients, Kakkar et al25 established that, among patients who underwent major orthopedic operations, 92.5% of patients were at a risk of DVT. In this study, the patients exhibited moderate risk level in Autar DVTRAS. According to the Autar DVTRAS, our results showed that aging, obesity,
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TABLE 4 PATIENTS’ AUTAR DEEP VEIN THROMBOSIS RISK ASSESSMENT SUBSCALE CHARACTERISTICS: BINARY LOGISTIC REGRESSION ANALYSIS (N = 102) Independent variables (subscale characteristics) Age-specific groups (years) 18-30 31-50 51-70 $71 Build/body mass index Average/desirable Overweight/obese Mobility Limited Very limited/complete bed rest Special risk category Oral contraceptives Hormone replacement therapy Trauma risk category (preoperative period) Yes No Surgical intervention Planned major surgery Emergency major surgery Current high-risk diseases Yes No
p Value
Unadjusted odds ratio
95% CI
.000* .002** .000*
23.49 10.02 20.49
(1.61-124.11) (3.74-273.62) (25.23-3495.775)
0.035***
13.51
(1.20-152.17)
0.002**
35.50
(3.65-345.56)
0.26
20.01
(0.11-3519.71)
110.58
(5.40-2262.74)
0.002**
0.54
4.86
0.001**
2237.15
(0.30-783.74)
(22.09-226586.67)
Deep vein thrombosis mean scores (12.77 5.66). *p # .001; **p # .01; ***p # .05.
immobility, and acute and chronic diseases were significant highlevel risk factors for postoperative DVT among those undergoing major orthopedic operations (Table 4). Edmonds et al9 concluded that the risk factors that show a significant association with postoperative DVT are aging, obesity, orthopedic surgery, past history of DVT, varicose veins, and general anesthesia; this is consistent with the recorded results of this study. Deitelzweig et al13 reported that those 40-60 years old who were immobilized after surgery had a moderate to high risk of DVT. In another study, Altıntas¸ et al10 found major risk factors to be obesity and prolonged immobilization after total hip arthroplasty, total knee arthroplasty, and hip fracture surgery. Gangireddy et al’s26 results reported that total hip arthroplasty had the highest incidence of DVT, and those patients of increased age, female gender had a significantly higher incidence of DVT postoperatively. Similarly, Anderson and Spencer14 reported that patients >40 years of age have a significantly increased risk of DVT compared with younger patients, and the risk approximately doubles with each
subsequent decade. Duff et al27 concluded that improved adherence to evidence-based guidelines for VTE prophylaxis is achievable and is likely to result in fewer deaths, fewer VTE events, and a significant overall cost savings.
LIMITATIONS This descriptive study was conducted in the orthopedic wards of one hospital and included a small number of patients. For these reasons, the generalizability of our research findings is limited to similar groups.
CONCLUSION DVT is a serious and potentially fatal condition. Determination of risk level and risk factors for DVT should be performed for every patient, especially in the postoperative period. This study focused on the risk level on DVT in patients undergoing
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major orthopedic operations. In addition, this study showed that the odds ratio of risk factors affected the postoperative DVT scores. Health care providers should be aware of contributory risk factors for DVT in patients undergoing major orthopedic surgery for minimizing them and preventing DVT. After recognizing the risk level, risk factors, and their odds ratio, nurses especially plan and implement individual nursing care for preventing DVT. The authors conclude that this is a key study for implementing evidence-based treatments from clinical guidelines to prevent DVT. For evidence-based clinical practice, these high-level risk factors (especially advanced age, greater BMI, immobility, and trauma risk level) should be taken into account when preventing DVT in orthopedic patients.
REFERENCES 1. Autar R. NICE guidelines on reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients undergoing surgery. J Orthop Nurs 2007; 11:169-76. 2. Caprini JA. Risk assessment as a guide for the prevention of the many faces of venous thromboembolism. Am Journal Surg 2010;199:3-10. 3. McRae SJ, Ginsberg JS. Update in the diagnosis of deep-vein thrombosis and pulmonary embolism. Curr Opin Anaesthesiol 2006;19:44-51. 4. White RH. The epidemiology of venous thromboembolism. Circulation 2003;107:14-8. 5. Watson T, Shantsila E, Lip GY. Mechanisms of thrombogenesis in atrial fibrillation: Virchow’s triad revisited. Lancet 2009;373:155-66. 6. Fowkes FJI, Price JF, Fowkes FGR. Incidence of diagnosed deep vein thrombosis in the general population: systematic review. Eur J Vasc Endovasc 2003;25:1-5. 7. Choi M, Hector M. Management of venous thromboembolism for older adults in long-term care facilities. JAANP 2012;24:335-44. 8. Collins R, MacLellan L, Gibbs H, et al. Venous thromboembolism prophylaxis: The role of the nurse in changing practice and saving lives. AJAN 2010;27:83-9. 9. Edmonds MJR, Crichton TJH, Runciman WB, et al. Evidence-based risk factors for postoperative deep vein thrombosis. ANZ J Surg 2004;74:1082-97. 10. Altıntas¸ F, G€urb€uz H, Erdemli B, et al. Venous thromboembolism prophylaxis in major orthopaedic surgery: a multicenter, prospective, observational study. Acta Orthop Traumatol Turc 2008;42:322-7. 11. Davis PS. Why move?. In: Kneale JD, Davis PS, Powell A, editors. Orthopaedic and trauma nursing. 2nd ed. Edinburgh, UK: Churchill Livingstone; 2005:87-95.
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12. Geerts W. Prevention of venous thromboembolism: A key patient safety priority. J Thromb Haemost 2009;7:1-8. 13. Deitelzweig S, McKean SC, Amin AN, et al. Prevention of venous thromboembolism in the orthopedic surgery patient. Clev Clin J Med 2008;75:27-36. 14. Anderson FA, Spencer FA. Risk factors for venous thromboembolism. Circulation 2003;107:9-16. 15. Caprini JA. Thrombosis risk assessment as a guide to quality patient care. Dis Mon 2005;51:70-8. 16. Rice KL, Walsh ME. Minimizing venous thromboembolic complications in the orthopaedic patients. Orthop Nurs 2001;20:21-7. 17. Bagaria V, Modi N, Panghate A, et al. Incidence and risk factors for development of venous thromboembolism in Indian patients undergoing major orthopaedic surgery: results of a prospective study. Postgrad Med J 2006;82:136-9. 18. Schiff RL, Kahn SR, Shrier I, et al. Identifying orthopaedic patients at high risk for venous thromboembolism despite thromboprophylaxis. Chest 2005;128:3364-71. 19. National Institute for Health and Care Excellence (NICE). Venous thromboembolism: reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients undergoing surgery. Available from: http://www.nice.org.uk/nicemedia/live/12695/47195/47195. pdf; 2007. Accessed 9 May 2014. 20. Morris B. Nursing initiatives for deep vein thrombosis prophylaxis: Pragmatic timing of administration. Orthop Nurs 2004;23:142-7. 21. Autar R. Nursing assessment of clients at risk of deep vein thrombosis (DVT): the Autar DVT scale. J Adv Nurs 1996; 23:763-70. 22. Autar R. The management of deep vein thrombosis: The Autar DVT risk assessment scale re-visited. J Orthop Nurs 2003;7:114-24. 23. Kaboli P, Henderson MC, White RH. DVT prophylaxis and coagulation in the surgical patient. Med Clin North Am 2003;87:77-110. 24. Kehl-Pruett W. Deep vein thrombosis in hospitalized patients. DCCN 2006;25:53-9. 25. Kakkar AJ, Cimminiello C, Goldhaber SZ, et al. Venous thromboembolism risk and prophylaxis in the acute care hospital setting (ENDORSE survey): findings in surgical patients. Ann Surg 2010;251:330-8. 26. Gangireddy C, Rectenwald JR, Upchurch GR, et al. Risk factors and clinical impact of postoperative symptomatic venous thromboembolism. J Vasc Surg 2007;45:335-42. 27. Duff J, Walker K, Omari A, et al. Prevention of venous thromboembolism in hospitalized patients: Analysis of reduced cost and improved clinical outcomes. J Vasc Nurs 2013;31:9-14.
JOURNAL OF VASCULAR NURSING www.jvascnurs.net
SEPTEMBER 2015
Risk level analysis for deep vein thrombosis (DVT): A study of Turkish patients undergoing major orthopedic surgery Funda B€ uy€ ukyılmaz, PhD, BSN, Merdiye S¸endir, PhD, BSN, Ricky Autar, DiPN, PhD, MSc, BA (HONS), _ and Ilknur Yazgan, MSc, RN
Deep vein thrombosis (DVT) is a prevalent problem for orthopedic patients, particularly owing to the nature of operative interventions and treatment procedures, predisposing to an high risk of DVT. This descriptive study was conducted to determine the levels of risk, the risk factors, and their odds ratio for DVT in patients undergoing major orthopedic surgery. Data were collected using a Patient Information Form and the Autar DVT Risk Assessment Scale (DVTRAS) in orthopedic wards of a university hospital on postoperative day 2. Data were analyzed using descriptive, comparative analysis, and binary logistic regression. The 102 patients (mean age, 52.58 21.58 years) were hospitalized for a mean of 14.35 14.56. Of the sample, 53.9% were female, 65.7% had a history of previous surgery, and 54.9% had undergone total hip/knee arthroplastic surgery, 67.6% of patients wore graduated compression stockings, and 62.7% were administered liquid infusion. Those patients had moderate risk score (12.77 5.66) in the Autar DVTRAS. According to binary logistic regression analysis, aging, obesity, immobility, and acute and chronic diseases were significant risk factors for postoperative DVT (p # .05). This study highlights evidence on the degree of DVT risk, risk factors, and impact of venous thromboembolism in patients undergoing major orthopedic operations. For evidence-based clinical practice, these high-level risk factors should be taken into account in the prevention of DVT in orthopedic patients. (J Vasc Nurs 2015;33:100-105)
Deep vein thrombosis (DVT) and venous thromboembolism (VTE) are serious causes of patient morbidity and mortality in hospitalized patients. VTE comprises DVT and pulmonary embolism, which results when a blood clot is formed in the deep veins (usually in the lower legs) and some or all of a clot detaches and travels to the lungs; this is a potentially fatal condition.1–4 The formation of a DVT can be owing to 1 or a combination of 3 predisposing factors, known as Virchow’s triad—vessel trauma, venous stasis, and hypercoagulability.5 From the Florence Nightingale Faculty of Nursing, Istanbul University, Istanbul, Turkey; Faculty of Health and Life Sciences, De Montfort University, Leicester, UK; Orthopedic and Traumatology Department, Istanbul Medical Faculty Hospital, Istanbul University, Istanbul, Turkey. Corresponding author: Funda B€uy€ukyılmaz, PhD, BSN, Assistant Professor, Fundamental of Nursing Department, Istanbul University Florence Nightingale Faculty of Nursing, 34381 _ S¸is¸li-Istanbul/Turkey. Tel.: +90 212 440 00 00 (27126); Fax: +90 212 224 49 90. (E-mails: fundabuyukyilmaz@hotmail. com, [email protected]). Conflicts of interest: The authors confirm that there are no financial or personal relationships with other people or organizations that inappropriately influenced this work. 1062-0303/$36.00 Copyright Ó 2015 by the Society for Vascular Nursing, Inc. http://dx.doi.org/10.1016/j.jvn.2015.01.004
DVT is a most prevalent problem for orthopedic patients, particularly owing to the nature of operative interventions and treatment procedures, predisposing to an high risk for DVT. In the postoperative period, the incidence of DVT is affected by preexisting factors such as surgical orthopedic procedures, the existence of infection, and the level of mobility.6–9 Major surgery and especially undergoing major orthopedic surgery (such as total hip arthroplasty, total knee arthroplasty, hip fracture surgery, spinal cord injury, and major trauma) confer the greatest risk for DVT because of postoperative immobility and the surgical trauma on the coagulation system inflicted by direct trauma to deep veins, and marked venous stasis subsequent to these procedures.10–13 Anderson and Spencer14 postulated that patients who underwent major orthopedic surgery had a moderate risk for DVT. Additional factors increasing the risk of DVT have also been identified, such as prior DVT history, myocardial infarction, congestive heart or respiratory failure, aging, obesity, and immobility.8,15,16 Similarly, a study by Bagaria et al17 established that the contributing risk factors found to be significantly responsible for the development of DVT were prolonged operation ($2 hours), prolonged immobility ($72 hours), and larger build/body mass index (BMI). In another study, Deitelzweig et al13 claimed that, for patients undergoing orthopedic surgery, DVT risk levels (low, moderate, high, and highest) may be increased by advancing age; other risk factors for DVT include current surgery and immobilization duration. Risk factors are additive and the more risk factors exist, the greater is the risk of DVT. For example, elderly female patients undergoing major
Vol. XXXIII No. 3
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Figure 1. Autar Deep Vein Thrombosis Risk Assessment Scale (2002).
orthopedic surgery on complete bed rest in the postoperative period are more prone to DVT/fatal pulmonary embolism.7,18 In this context, the National Institutes for Health and Care Excellence19 guidelines emphasized that DVT risk level determination is an essential strategy for the implementation of appropriate care for patients perioperatively. It is therefore imperative that health care providers routinely assess their patients’ DVT risk using the tools that have been developed and tested.1,2,11,15 After this, health care providers must plan and implement prophylactic interventions according to the patients’ risk assessment score and calculate their risk factors odds ratio for DVT.8,15,20 The purpose of this study was to determine the levels of risk, the risk factors, and their odds ratio for DVT in patients undergoing major orthopedic surgery. The research questions were:
What are the patients’ levels of risk for DVT? What are the risk factors for DVT in patients undergoing major orthopedic surgery?
What are the odds ratio effect of the risk factors on patients undergoing major orthopedic surgery? MATERIAL AND METHODS
Design, sample, and criteria for participation This descriptive study was conducted in the orthopedic wards of a university hospital in Turkey between January 2010 and 2011. The study sample consisted of 102 patients who met the inclusion criteria and agreed to participate in the study. The following inclusion and exclusion criteria were applied. Patients who were 18 years or older, mentally lucid enough to answer questions, hospitalized for a major operative procedure (total hip or knee arthroplasty, osteosarcoma, or hemiarthroplasty). They would also be the recipient of same prophylactic procedures during the postoperative period (enoxaparin via subcutaneous administration), graduated compression stockings and early ambulation 24–48 hours postoperatively with stockings,
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were admitted to the study. Those with cognitive, affective, and verbal impairment, and another acute illness causing DVT and the development of any complications during the perioperative period were excluded.
Ethical considerations Ethical considerations were duly applied and the ethics committee of the university hospital approved this study. Patients were informed orally of the purpose of the study, and informed consent was sought by the researchers. Potential respondents who met the inclusion criteria and willing were given oral and written information by the researchers regarding the aim of the study, assurance of anonymity and confidentiality, and the right to refuse to participate. No identifiable data were collected.
Data collection instruments A patient information form and the Autar DVT Risk Assessment Scale (Autar DVTRAS) were used on patients on the morning of second postoperative day to assess their risk of DVT. For the purpose of consistency, these instruments were administered for 2–3 minutes by 1 researcher to all of the participants in face-to-face interviews in the patients’ rooms.
The patient information form The patient information form was developed by the researchers based on a literature review and included questions on sociodemographics, previous surgical history, types of current surgery, and implementing interventions about DVT during the hospitalization period.8,11,20–22
The Autar DVTRAS The Autar DVTRAS was designed to determine the patients’ risk of DVT. It consists of subscales, such as age group, BMI, mobility, special risk category, trauma risk category, surgical intervention, and current high-risk diseases (Figure 1). Within each section, subcategories are arranged generally in ascending numerical order to provide an overall picture of a higher score representing increased risk of DVT. The total score obtained from the Autar DVTRAS results in the following risk categories for DVT: high ($15), moderate (11-14), low (7-10), or no risk (#6).21,22 The original scale was developed by Autar (1994) and revised by the author in 2003. Autar (2003) calculated the Cronbach a value to be 0.88-0.95.22
Reliability and validity study for Turkish version of the Autar DVTRAS The researchers first obtained written permission from Dr. Ricky Autar to adapt the Autar DVTRAS for a Turkish version. A reliability and validity study for the Turkish version of Autar DVTRAS was conducted by authors. To ensure the quality of the Turkish Autar DVTRAS, an internationally accepted forwardback-translation technique was used to translate the English version of the Autar DVTRAS to a Turkish equivalent of the original instrument. Then, Turkish language equivalence of the scale reliability and validity analysis was provided. Reliability was assessed by measuring the stability, equivalence, and internal consistency of this instrument. The Autar DVTRAS was a stable instrument over the passage of time (rS = 0.78; p # .001). Inter-rater reliability
SEPTEMBER 2015
TABLE 1 PATIENT CHARACTERISTICS (N = 102) Characteristic Gender Female Male Educational level Read and write Primary school High school University Marital status Single Married Divorced/widowed Previous surgery history Yes No Type of surgery Total hip/knee arthroplasty Hemiarthroplasty Vertebrae reconstruction Tumor resection
n
%
55 47
53.9 46.1
17 45 22 18
16.7 44.1 21.6 17.6
27 49 26
26.5 48.0 25.5
67 35
65.7 34.3
56 30 8 8
55.0 29.4 7.8 7.8
demonstrated the equivalence of Autar DVTRAS when different raters used the instrument to assess individual’s risk of developing DVT. There were no differences in the Autar DVTRAS scores obtained by the 2 separate raters (p # .001). Internal consistency reliability by Cronbach a coefficient for the Autar DVTRAS was 0.62-0.67, which indicates that the tool was homogenous. For content validity, a panel of professional experts (10 orthopedists, 10 physiotherapists, 10 nurses, and 10 nurse faculty members) assessed the content and clarity of the items in detail. Construct validity was established by contrasting patients with DVT and non- DVT subjects (N = 84). The Autar DVTRAS was able to differentiate between those who were expected to be at high risk of DVT risk and those who were expected to be low risk for DVT. The Autar DVTRAS was administered by 1 researcher to patients who agreed to participate. In the present study, the Cronbach a statistical value was calculated to be 0.78-0.90.
Data analysis Data were analyzed using the Statistical Package for Social Science for Windows (SPSS) version 21.0 (IBM Corp., Armonk, NY). Descriptive statistics were computed. A binary logistic regression model with a backward stepwise procedure was performed in order to identify the risk factors associated with DVT risk scores in the postoperative period. In this study, a p < .05 was considered significant.
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TABLE 3 EFFECT OF PATIENTS’ AUTAR DEEP VEIN THROMBOSIS RISK ASSESSMENT SUBSCALE CHARACTERISTICS ON THEIR MEAN SCORES (N = 102) Subscale characteristics Figure 2. Preventive interventions toward deep vein thrombosis (DVT) during the hospitalization period*. *More than 1 preventive interventions were implemented.
TABLE 2 MEAN SCORES OF AUTAR DEEP VEIN THROMBOSIS RISK ASSESSMENT SCALE Variables
Min-Max
Age groups Body mass index Mobility Special risk category Trauma risk category Surgical intervention Current high-risk diseases Total score
0-5 0-4 0-4 0-3 0-7 2-4 0-5 2-23
Mean SD 2.67 1.53 1.81 0.24 2.30 3.10 1.16 12.77
1.96 0.98 1.47 0.66 1.96 0.91 1.72 5.66
RESULTS Patient characteristics are provided in Table 1. In addition, 67.6% of patients wore graduated compression stockings, and 62.7% were administered liquid infusion to prevent DVT from dehydration during the hospitalization period (14.35 14.56 days; Figure 2). The mean scores and standard deviations for patients’ DVT risk levels are provided in Table 2. The patients’ subscale characteristics are shown in Table 3. In addition, according to binary logistic regression analysis, patients in the 31-50, 51-70, and $71 years age groups had 23.49 times, 10.02 times, and 20.49 times, respectively, higher postoperative DVT risk than those in the 18-30 years age group. The patients who exhibited an overweight/obese BMI (odds ratio [OR], 13.51), had very limited to complete bed rest mobility level (OR, 35.50), trauma risk in the preoperative period (especially pelvic and lower limb injury; OR, 110.58), or current high-risk diseases (especially chronic heart disease; OR, 2237.15) with a high postoperative DVT risk (Table 4).
DISCUSSION The focus of this study was to identify the level of DVT risk, risk factors, and their effects on postoperative DVT scores in patients undergoing major orthopedic operations. The literature
n
%
Age-specific group (years) 18-30 23 22.5 31-50 23 22.5 51-70 27 26.5 $71 29 28.5 (mean SD = 52.58 21.58) Build/body mass index Average/desirable 60 58.8 Overweight/Obese 42 41.2 Mobility Limited 53 52.0 Very limited/ 49 48.0 complete bed rest Special risk category Oral contraceptives 93 91.2 Hormone 9 8.8 replacement therapy Trauma risk category (preoperative period) Yes 62 60.8 No 40 39.2 Surgical intervention Planned major 84 82.4 surgery Emergency major 18 17.6 surgery Current high-risk diseases Yes 34 33.3 No 68 66.7
DVT (Mean SD)
6.83 10.52 13.93 18.21
3.17 3.07 4.79 3.74
11.46 5.02 15.86 5.00 10.50 4.08 16.24 4.82
12.45 5.52 14.14 5.76
15.68 4.68 8.28 3.83 12.54 5.62 13.89 5.88
18.47 4.06 9.93 4.06
showed that, although all hospitalized patients had the potential to develop DVT, certain factors increase this risk.22–24 In a large study of 18,461 patients, Kakkar et al25 established that, among patients who underwent major orthopedic operations, 92.5% of patients were at a risk of DVT. In this study, the patients exhibited moderate risk level in Autar DVTRAS. According to the Autar DVTRAS, our results showed that aging, obesity,
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TABLE 4 PATIENTS’ AUTAR DEEP VEIN THROMBOSIS RISK ASSESSMENT SUBSCALE CHARACTERISTICS: BINARY LOGISTIC REGRESSION ANALYSIS (N = 102) Independent variables (subscale characteristics) Age-specific groups (years) 18-30 31-50 51-70 $71 Build/body mass index Average/desirable Overweight/obese Mobility Limited Very limited/complete bed rest Special risk category Oral contraceptives Hormone replacement therapy Trauma risk category (preoperative period) Yes No Surgical intervention Planned major surgery Emergency major surgery Current high-risk diseases Yes No
p Value
Unadjusted odds ratio
95% CI
.000* .002** .000*
23.49 10.02 20.49
(1.61-124.11) (3.74-273.62) (25.23-3495.775)
0.035***
13.51
(1.20-152.17)
0.002**
35.50
(3.65-345.56)
0.26
20.01
(0.11-3519.71)
110.58
(5.40-2262.74)
0.002**
0.54
4.86
0.001**
2237.15
(0.30-783.74)
(22.09-226586.67)
Deep vein thrombosis mean scores (12.77 5.66). *p # .001; **p # .01; ***p # .05.
immobility, and acute and chronic diseases were significant highlevel risk factors for postoperative DVT among those undergoing major orthopedic operations (Table 4). Edmonds et al9 concluded that the risk factors that show a significant association with postoperative DVT are aging, obesity, orthopedic surgery, past history of DVT, varicose veins, and general anesthesia; this is consistent with the recorded results of this study. Deitelzweig et al13 reported that those 40-60 years old who were immobilized after surgery had a moderate to high risk of DVT. In another study, Altıntas¸ et al10 found major risk factors to be obesity and prolonged immobilization after total hip arthroplasty, total knee arthroplasty, and hip fracture surgery. Gangireddy et al’s26 results reported that total hip arthroplasty had the highest incidence of DVT, and those patients of increased age, female gender had a significantly higher incidence of DVT postoperatively. Similarly, Anderson and Spencer14 reported that patients >40 years of age have a significantly increased risk of DVT compared with younger patients, and the risk approximately doubles with each
subsequent decade. Duff et al27 concluded that improved adherence to evidence-based guidelines for VTE prophylaxis is achievable and is likely to result in fewer deaths, fewer VTE events, and a significant overall cost savings.
LIMITATIONS This descriptive study was conducted in the orthopedic wards of one hospital and included a small number of patients. For these reasons, the generalizability of our research findings is limited to similar groups.
CONCLUSION DVT is a serious and potentially fatal condition. Determination of risk level and risk factors for DVT should be performed for every patient, especially in the postoperative period. This study focused on the risk level on DVT in patients undergoing
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major orthopedic operations. In addition, this study showed that the odds ratio of risk factors affected the postoperative DVT scores. Health care providers should be aware of contributory risk factors for DVT in patients undergoing major orthopedic surgery for minimizing them and preventing DVT. After recognizing the risk level, risk factors, and their odds ratio, nurses especially plan and implement individual nursing care for preventing DVT. The authors conclude that this is a key study for implementing evidence-based treatments from clinical guidelines to prevent DVT. For evidence-based clinical practice, these high-level risk factors (especially advanced age, greater BMI, immobility, and trauma risk level) should be taken into account when preventing DVT in orthopedic patients.
REFERENCES 1. Autar R. NICE guidelines on reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients undergoing surgery. J Orthop Nurs 2007; 11:169-76. 2. Caprini JA. Risk assessment as a guide for the prevention of the many faces of venous thromboembolism. Am Journal Surg 2010;199:3-10. 3. McRae SJ, Ginsberg JS. Update in the diagnosis of deep-vein thrombosis and pulmonary embolism. Curr Opin Anaesthesiol 2006;19:44-51. 4. White RH. The epidemiology of venous thromboembolism. Circulation 2003;107:14-8. 5. Watson T, Shantsila E, Lip GY. Mechanisms of thrombogenesis in atrial fibrillation: Virchow’s triad revisited. Lancet 2009;373:155-66. 6. Fowkes FJI, Price JF, Fowkes FGR. Incidence of diagnosed deep vein thrombosis in the general population: systematic review. Eur J Vasc Endovasc 2003;25:1-5. 7. Choi M, Hector M. Management of venous thromboembolism for older adults in long-term care facilities. JAANP 2012;24:335-44. 8. Collins R, MacLellan L, Gibbs H, et al. Venous thromboembolism prophylaxis: The role of the nurse in changing practice and saving lives. AJAN 2010;27:83-9. 9. Edmonds MJR, Crichton TJH, Runciman WB, et al. Evidence-based risk factors for postoperative deep vein thrombosis. ANZ J Surg 2004;74:1082-97. 10. Altıntas¸ F, G€urb€uz H, Erdemli B, et al. Venous thromboembolism prophylaxis in major orthopaedic surgery: a multicenter, prospective, observational study. Acta Orthop Traumatol Turc 2008;42:322-7. 11. Davis PS. Why move?. In: Kneale JD, Davis PS, Powell A, editors. Orthopaedic and trauma nursing. 2nd ed. Edinburgh, UK: Churchill Livingstone; 2005:87-95.
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12. Geerts W. Prevention of venous thromboembolism: A key patient safety priority. J Thromb Haemost 2009;7:1-8. 13. Deitelzweig S, McKean SC, Amin AN, et al. Prevention of venous thromboembolism in the orthopedic surgery patient. Clev Clin J Med 2008;75:27-36. 14. Anderson FA, Spencer FA. Risk factors for venous thromboembolism. Circulation 2003;107:9-16. 15. Caprini JA. Thrombosis risk assessment as a guide to quality patient care. Dis Mon 2005;51:70-8. 16. Rice KL, Walsh ME. Minimizing venous thromboembolic complications in the orthopaedic patients. Orthop Nurs 2001;20:21-7. 17. Bagaria V, Modi N, Panghate A, et al. Incidence and risk factors for development of venous thromboembolism in Indian patients undergoing major orthopaedic surgery: results of a prospective study. Postgrad Med J 2006;82:136-9. 18. Schiff RL, Kahn SR, Shrier I, et al. Identifying orthopaedic patients at high risk for venous thromboembolism despite thromboprophylaxis. Chest 2005;128:3364-71. 19. National Institute for Health and Care Excellence (NICE). Venous thromboembolism: reducing the risk of venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients undergoing surgery. Available from: http://www.nice.org.uk/nicemedia/live/12695/47195/47195. pdf; 2007. Accessed 9 May 2014. 20. Morris B. Nursing initiatives for deep vein thrombosis prophylaxis: Pragmatic timing of administration. Orthop Nurs 2004;23:142-7. 21. Autar R. Nursing assessment of clients at risk of deep vein thrombosis (DVT): the Autar DVT scale. J Adv Nurs 1996; 23:763-70. 22. Autar R. The management of deep vein thrombosis: The Autar DVT risk assessment scale re-visited. J Orthop Nurs 2003;7:114-24. 23. Kaboli P, Henderson MC, White RH. DVT prophylaxis and coagulation in the surgical patient. Med Clin North Am 2003;87:77-110. 24. Kehl-Pruett W. Deep vein thrombosis in hospitalized patients. DCCN 2006;25:53-9. 25. Kakkar AJ, Cimminiello C, Goldhaber SZ, et al. Venous thromboembolism risk and prophylaxis in the acute care hospital setting (ENDORSE survey): findings in surgical patients. Ann Surg 2010;251:330-8. 26. Gangireddy C, Rectenwald JR, Upchurch GR, et al. Risk factors and clinical impact of postoperative symptomatic venous thromboembolism. J Vasc Surg 2007;45:335-42. 27. Duff J, Walker K, Omari A, et al. Prevention of venous thromboembolism in hospitalized patients: Analysis of reduced cost and improved clinical outcomes. J Vasc Nurs 2013;31:9-14.