|Year : 2021 | Volume
| Issue : 1 | Page : 28-34
Venous thromboembolism risk and adequacy of thromboprophylaxis in surgical patients
Besty Ann Varghese1, Punitha Ezhilarasu2, Amala Rajan3, Mark Ranjan Jesudason4, Visalakshi Jeyaseelan5
1 Staff Nurse, University Hospital Limerick, Ireland, Europe
2 Former Professor & Dean, College of Nursing, Christian Medical College, Vellore, Tamil Nadu, India
3 Former Professor, College of Nursing, Christian Medical College, Vellore, Tamil Nadu, India
4 Professor, Department of General Surgery, Christian Medical College, Vellore, Tamil Nadu, India
5 Former Lecturer, Department of Biostatistics, Christian Medical College, Vellore, Tamil Nadu, India
|Date of Submission||20-Feb-2020|
|Date of Decision||28-Sep-2020|
|Date of Acceptance||14-Oct-2020|
|Date of Web Publication||07-Jul-2021|
Mrs. Besty Ann Varghese
Staff Nurse, University Hospital Limerick, Ireland
Source of Support: None, Conflict of Interest: None
Venous thromboembolism (VTE) is the most prevalent potentially preventable complication amongst surgical patients. Appropriate prophylaxis is quite effective in its prevention. Mechanical and pharmacological thromboprophylaxis can be instituted based on risk categorisation. This study was undertaken to assess the risk for development of VTE in surgical patients and to assess the adequacy of thromboprophylaxis. A descriptive research design was used and was conducted in the general surgical wards of a tertiary hospital in South India. All 385 patients who were admitted in the surgical wards during the data collection period were included in the study, and the VTE Risk Assessment Tool by the Department of Health (2008b), UK, was used to assess the VTE risk in these patients. Eighty per cent of the patients were at high risk for developing VTE, and majority (62.7%) of them were not on any method of thromboprophylaxis. Only a minority (11.7%) of those who belonged to moderate or low risk were found to be on thromboprophylaxis. Majority of the patients who were found to be at high risk and were on prophylaxis for VTE were on anti-embolism stockings. More than half of the patients who were at low or moderate risk for VTE were found to be on injection heparin administered subcutaneously. There was a statistically significant association between age, type of occupation, the number of days of hospital stay, type of surgery, mobility level of patients and the VTE risk. Implementation of VTE risk assessment tool and a protocol for thromboprophylaxis helps in prevention of VTE and the complications associated with thromboprophylaxis. Incorporating this topic as a regular in-service education can ensure its mandatory learning and practice by nurses – the front line caregivers.
Keywords: Risk assessment, risk categorisation, thromboprophylaxis, venous thromboembolism, venous thromboembolism risk assessment tool
|How to cite this article:|
Varghese BA, Ezhilarasu P, Rajan A, Jesudason MR, Jeyaseelan V. Venous thromboembolism risk and adequacy of thromboprophylaxis in surgical patients. Indian J Cont Nsg Edn 2021;22:28-34
|How to cite this URL:|
Varghese BA, Ezhilarasu P, Rajan A, Jesudason MR, Jeyaseelan V. Venous thromboembolism risk and adequacy of thromboprophylaxis in surgical patients. Indian J Cont Nsg Edn [serial online] 2021 [cited 2021 Aug 1];22:28-34. Available from: https://www.ijcne.org/text.asp?2021/22/1/28/320821
| Introduction|| |
Venous thromboembolism (VTE), a global patient safety concern, is one of the most prevalent reasons for unintended readmission and preventable deaths in hospitalised patients. It can also affect the quality of life, prolong the hospital stay and delay recovery. There is an increased need for awareness of serious implications of VTE and its related morbidity and mortality amongst healthcare professionals, patients and the general public.
VTE is the formation of blood clot (thrombus) in the vein, and it constitutes deep vein thrombosis (DVT) and pulmonary embolism (PE). The clot obstructs the blood flow through the affected vessel resulting in pain and swelling. The embolus – the mobile clot, which dislodges from its origin, travels through the venous system and lodges in the lung resulting in fatal PE. VTE results in devastating sequelae which include post-thrombotic syndrome, recurrent VTE and chronic PE with pulmonary hypertension.
Timely and appropriate evidence-based recommendations should be applied to reduce the burden of VTE. Unfortunately, despite its clinical importance, the rate of risk assessment and administration of appropriate thromboprophylaxis, which is the best method to prevent VTE, is not up to standard in most of the hospitals. The risks for each individual to develop VTE vary and hence assessment of risk for each individual helps to ensure appropriate thromboprophylaxis – the 'number one' patient safety practice., There are pharmacological and mechanical methods of prophylaxis which are declared to be safe and cost-effective, if used judiciously. Mechanical prophylactic measures include use of anti-embolic stockings (knee/thigh length), foot impulse devices and intermittent pneumatic compression devices. Anticoagulants often used include aspirin, unfractionated heparin, low-molecular-weight heparins (LMWHs) such as enoxaparin, dalteparin and Vitamin K antagonists (for example, warfarin, acenocoumarol, phenindione and dicoumarol) and fondaparinux, a selective factor Xa inhibitor.
Nurses, who spend more time with the patients than any other health professionals, can act as a real-time safety net by ensuring that the patient is on appropriate thromboprophylaxis. With adequate education and guidelines, nurses can be competent in the prevention and early identification of VTE and also implementation of effective and appropriate thromboprophylaxis, thereby ensuring patient safety and improving the quality of care.
VTE is the second most frequent medical complication amongst post-operative patients. On being hospitalised, almost all patients are at risk for VTE as they possess at least one risk factor. Lack of appropriate thromboprophylaxis can result in DVT in about 10%–40% amongst medical or general surgery patients and 40%–60% in post-operative orthopaedic patients.
The system of thromboprophylaxis – a simple, cheap and effective method to prevent VTE – is found to be underutilised in most of the inpatient settings. The cost burden in managing VTE is significantly higher ranging from US$347 to US$2,651 compared to thromboprophylaxis. According to a study by Pandey et al., at the Department of Medicine, All India Institute of Medical Sciences, New Delhi, it was found that 75% of the patients in the medical wards and intensive care unit had the highest risk for VTE, but unfortunately, out of these, only 12.5% of the patients were on thromboprophylaxis within the 48 h of admission. A retrospective study conducted in Christian Medical College, Vellore, from 1996 to 2005 revealed that the incidence of confirmed VTE was 17.46 per 10,000 admissions and 5 per 10,000 operations.
As VTEs are asymptomatic in most of the cases, risk assessment is well thought out to be the chief step in VTE prevention and it is, therefore, mandatory to ensure that all hospitalised patients receive appropriate thromboprophylaxis accordingly. Pharmacological methods of thromboprophylaxis have the potential to cause bleeding in patients whereas mechanical methods do not. Therefore mechanical thromboprphylaxis can be considered as a positive option to prevent VTE especially when it is known to reduce the risk of VTE by two-thirds when used as a single therapy and halves the risk when combined with other forms of therapy.
The objectives of the study were as follows:
- To assess the risk for development of VTE in surgical patients
- To associate the risk for development of VTE with selected demographic and clinical variables of surgical patients
- To assess the adequacy of thromboprophylaxis of patients based on their VTE risk
- To assess the various methods of thromboprophylaxis received by the patients based on their VTE risk
- To assess the risk for bleeding in surgical patients.
| Methods|| |
A descriptive research design was adopted for the study. The study was conducted in the selected surgical and orthopaedic wards of a tertiary care hospital in South India, and all patients above 18 years of age admitted in these wards during 3 weeks of data collection period were selected for the study. All the admitted patients in the selected surgical wards were assessed for their risk to develop VTE. The selected wards included 3 general surgery wards (44 beds each), 1 orthopaedic ward (48 beds) and 2 semi-private wards with surgical and orthopaedic patients (28 and 25 beds). Some of the surgeries for which patients were admitted in these wards are for vascular, colorectal, head and neck, upper and lower gastrointestinal, mastectomy, amputation, hepato-pancreatico-biliary, total knee replacement, total hip replacement, hip/knee arthroplasty, open reduction and internal fixation, debridement, thyroidectomy and other general surgeries.
The sample size was calculated using the formula
The required sample size to find the prevalence of about 25% with 4.5% precision and 95% confidence interval was found to be 370 patients. All the potentially eligible patients (385 patients) admitted during the data collection time were recruited for the study.
The instrument used for the study was divided into the following parts:
- Part I included the demographic and clinical profile of the patient developed by the investigator
- Part II included The VTE Risk Assessment Scale by the Department of Health (2008b), UK., It includes various patient- and procedure-related factors such as age, previous history of PE/DVT, family history of DVT/PE, active cancer, acute or chronic lung diseases, acute or chronic inflammatory diseases, chronic heart failure or myocardial infarction, lower-limb paralysis, acute infectious disease, body mass index >30, bedridden for 3 days or more, pregnancy or puerperium, surgery planned/performed, presence of central venous catheter, hip or knee replacement, hip fracture, lower-limb injury, other major orthopaedic surgery, inflammatory or intra-abdominal condition, use of contraceptives or hormone replacement therapy, dehydration, surgical procedure lasting for more than 30 min and plaster cast immobilisation. The tool also contains factors which contribute to bleeding risk. The permission to use the tool is provided freely by the Department of Health under the Open Government License for Public Sector Information.
The tool was developed by an expert group in the Department of Health, UK, and is being used by the hospitals in the UK. The details on its validity and reliability were not available. The tool was modified by the investigator based on the guidelines of the Department of Health, UK (2010), under National Institute of Clinical Guidance and was assessed for its content validity by the medical and nursing experts. The content validity index was found to be 0.87.
The patient- and procedure-related factors contributing to the thrombosis risk were reviewed, ticking each box that applied. The patient was then classified to be at high, moderate and low risk according to the number of risks identified. The related factors against bleeding were also reviewed and ticked against the corresponding box. Thus, the patients were also assessed whether they were at risk for bleeding. This information was collected through interview technique and from patients' records. Approximately a maximum of 10 min was taken for each patient. If the patient was on any type of mechanical or pharmacological prophylaxis, during the time of assessment, it was considered that prophylactic measures were implemented.
Informed written consent was obtained from the patients prior to commencement of the study. Ethical clearance was obtained from the Institutional Review Board.
| Results|| |
The data were analysed using the Statistical Package for the Social Sciences for Windows (version 17.0). P < 0.05 was considered to be statistically significant in this study. Descriptive statistics was used to present the frequency and percentage of the demographic variables. Chi-square test was used to analyse the study findings.
Demographic characteristics indicated that amongst the 385 patients assessed, the majority of them (23.6%) were in the age group of 51–60 years. Amongst the participants, 262 (68.1%) were males and 182 of the participants (47.3%) were sedentary workers. Clinical variables illustrated that 286 (74.3%) of them belonged to the general surgery unit. Amongst the participants, 233 (60.5%) of them did not suffer from any other comorbidities and 314 (81.6%) of the participants were non-smokers. The majority of the participants were found to be post-operative (52.2%) and 297 (77.1%) of them were ambulant. Three hundred and forty-six participants out of the 385 participants (89.9%) were not on any central line at the time of assessment. Amongst the 39 participants who were on a central line, 17 (43.6%) of them had the line for more than 3 days. Amongst the 385 participants, 370 (96.1%) and 378 (98.2%) of them had no previous history of chemotherapy or radiation therapy, respectively.
Based on the risk categorisation of the study patients as high, moderate and low risk to develop VTE, frequency and percentages were calculated. [Figure 1] shows that amongst the 385 participants, 308 (80%) of them were found to be at high risk, 54 participants (14%) at moderate risk and 23 participants (6%) at low risk [Figure 1].
|Figure 1: Prevalence of patients at risk for developing venous thromboembolism (n = 385)|
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There was a statistically significant association between age and the risk to develop VTE [Table 1]. About 70% of the patients from all the age groups were found to be at high risk. All the patients (100%) who belonged to the age group of above 60 years were found to be at high risk. As age advanced, the risk of the patient to develop VTE increased. There is a significant association between the type of occupation and the VTE risk. About 70% of the patients from all categories were found to be at high risk for VTE, but those who belonged to the sedentary type were at the highest risk. No evidence of significant association between gender and VTE risk was found from the study.
|Table 1: Association between the risks for development of venous thromboembolism and selected demographic variables of surgical patients|
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The orthopaedic patients (95.9%) were found to be at higher risk for VTE compared to the general surgery patients (4.1%). Statistically, it is disclosed that there is an association between the disease condition and VTE. There was a statistically significant association between the number of days of hospital stay and the VTE risk. About 75% of the patients were found to be at high risk for VTE irrespective of their duration of hospital stay. All the patients who were hospitalised for a period of more than 1 month were found to be at high risk. There is a statistically significant association between VTE risk and the level of mobility. More than 90% of the patients who had difficulty in ambulation were found to be at high risk for VTE [Table 2].
|Table 2: Association between the risks for development of venous thromboembolism with selected clinical variables of surgical patients|
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There was a significant association between the VTE risk and the presence of central line, but it was found that there is no significant association statistically between the number of days on a central line and the VTE risk (P > 0.05). About 97% of the patients who were on central line were found to be at high risk for VTE. There was a significant association between VTE risk and previous history of chemotherapy (P = 0.049) but not with that of radiation therapy (P = 0.353). No evidence of significant association between VTE risk and other clinical variables such as comorbidities, smoking, operative status and a previous history of radiation therapy was revealed from the study [Table 2].
Only 37.3% of the VTE high-risk patients received thromboprophylaxis, which was found to be inadequate [Figure 2]. Amongst the patients who were at risk for moderate or low risk for VTE, 11.7% of them received thromboprophylaxis. [Figure 3] shows the methods of thromboprophylaxis in surgical patients.
|Figure 2: Adequacy of thromboprophylaxis based on venous thromboembolism risk|
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It is evident from [Figure 3] that amongst the VTE high-risk patients, the most common method of thromboprophylaxis received was anti-embolism stockings and the least was injection LMWH. On the other hand, amongst the VTE moderate/low-risk patients, injection heparin was the most dominant method of thromboprophylaxis and none of these patients received a combination of injection heparin and anti-embolism stockings.
[Figure 4] reveals that only a minority (10.9%) of patients were at risk for bleeding.
| Discussion|| |
The demographic variables assessed in this study were age, gender and occupation. From the findings of the study, it was evident that the majority (23.6%) of the patients belonged to the age group of 51–60 years and about 47.3% (n = 182) of them were sedentary workers. A greater portion (68.1%) of the patients was male. This is consistent with the study conducted by Soomro et al. in Chandka Medical College Hospital at Larkana, Pakistan, amongst 170 general medical and surgical patients who were assessed for the risk for development of VTE and found that 91 (53.1%) of the study participants were males. However, in this Pakistan study, the mean age of the study patients was found to be 39 + 16 years which was less compared to the present study.
The clinical variables incorporated in this study were disease classification, comorbidities, smoking, length of hospital stay, operative status, level of mobility, presence of central line and number of days on central line, history of previous chemotherapy and radiation therapy. Majority of the patients (66.2%) were assessed during their first to the 3rd day of hospitalisation. In a similar study done by Pendergraft et al. amongst medical inpatients, it was reported that 48.4% of the patients were hospitalised for <3 days and 51.6% of them exceeded 3 days of hospitalisation.
It was revealed from the study that a greater proportion (80%) of surgical patients were at high risk, 14% at moderate risk and 6% at low risk. Similar results were reported in an observational study in Turkey amongst the general surgery patients, which revealed that 62.1% of patients were at high risk for VTE. In the Turkey study, only 65.9% were on appropriate thromboprophylaxis, whereas in the current study, only 37.3% of the high-risk group were on thromboprophylaxis revealing an inadequacy in taking care of this aspect in patients. It was established from the current study that as age advances, the risk of the patient to develop VTE increases. This finding is in congruence with the literature review by Heit et al. In the study, majority (47.3%) of them were sedentary workers, and it was found that there is an association between the type of occupation and chance to develop VTE. This is in concordance with the study conducted at VTE Clinics and Coronary Care Unit, Wellington and Kenepuru Hospitals, New Zealand, where it was found that sedentary occupation is associated with an increased risk of VTE in the univariate analysis with an odds ratio of 1.7 (1.1–2.5) and P = 0.014.
The study findings revealed that amongst the orthopaedic patients, quite a large proportion are at higher risk for developing VTE compared to those who underwent general surgery. Any kind of surgery is a risk factor to develop VTE, however, orthopaedic patients are highly susceptible as a consequence of various prothrombotic processes such as coagulation activation from tissue and bone injury, injuries to the veins, heat resulting from cement polymerisation, decreased venous emptying during and after surgery and immobilisation.
Statistically, it was disclosed that there is an association between the disease condition and VTE. The study findings are in congruence with the conclusion of White et al. that the magnitude and the pattern of VTE change significantly based on the type of surgery. They also stated that the association of the disease condition on VTE is complex as it can also be affected by other factors like age. However, the type of surgery and the underlying disease process supersedes other risk factors. The level of mobility has a significant association with VTE risk. This is in line with the results obtained by Soomro et al. where it was pointed out that the most common risk factor (54.7%) for VTE is immobility. As duration of hospital stay increased, VTE risk for patients increased in this study. This was in congruence with a retrospective study in the United States in which some of the reasons designated to this increased susceptibility to VTE are increased severity of the illness, decreased level of mobility, increased age, multiple comorbidities and some other factors. All the patients who had a previous history of chemotherapy were found to be at high risk for VTE in the current study. Chemotherapy is known to activate the coagulation system and aggravate the prothrombotic state in malignancy. This is in concordance with the findings of the cohort study done by Khorana et al. in the US amongst the cancer patients who had developed VTE in which 18.1%, 47% and 72.5% of them had their first event within the 1st month, first 3 months and first 6months, respectively.
The study revealed that the greater proportion of patients (80%) was on high risk, 14% on moderate risk and 6% on low risk to develop VTE. However, only about one-tenth of the participants were at bleeding risk. 62.7% of high-risk patients and 88.3% of moderate or low risk were not on any thromboprophylaxis. Different surgical units in the hospital had different protocols for administering thromboprophylactic measures to the patients. Lack of use of a VTE risk assessment tool or absence of uniform thromboprophylaxis protocol would have contributed to the underutilisation of thromboprophylaxis. On a similar study conducted amongst general surgical patients in a tertiary care hospital in Kerala, 24%, 35% and 41% were at high, moderate and low risk, respectively, and bleeding risk was positive in 28% of them. Furthermore, mechanical prophylaxis was administered to 14% of the patients, amongst which 5% of them received elastic compression stocking and 9% received sequential compression device. Furthermore, pharmacological prophylaxis was administered for 14% of the patients. Eleven per cent of them received injection LMWH and the remaining 3% received injection heparin. Only 8% of the patients received a combination of mechanical and pharmacological thromboprophylaxis.
Overall, the study revealed that majority of the surgical patients were at high risk for developing thromboembolism, but only one-third of those who were at high risk were on thrombolytic measure. A uniform method of assessment by including thromboembolism risk assessment in the pre-operative care and early initiation of nurse-driven mechanical thromboembolytic measure may be beneficial for patients and will reduce mortality and morbidity in surgical patients. Nurses, along with physicians, are responsible for assessing the risk of the patients to develop VTE and to ensure they are on appropriate thromboprophylaxis according to the written institutional guidelines which are evidence based. Nurses should assess the patients at the time of admission, daily and also at the time of discharge. Before the use of various modalities of thromboprophylaxis, nurses should assess for its indications and contraindications and should administer them correctly, thereby ensuring patient safety and improving comfort. They can also ensure that all the hospitalised patients adhere to other preventive strategies of VTE such as ambulation, irrespective of their risk. Nurses need to be educated and reinforced on problems associated with VTE, its prevention and various thromboprophylactic measures, and the topic should be covered regularly in the in-service education sessions. Prevention of VTE and use of anti-embolism stockings can also be included as a part of 'health teaching topics' used in the institution. The standardised 'VTE risk assessment tool for nurses' (by the Department of Health, UK, 2008b) was recommended for use in the surgical wards, which enables nurses to be involved actively in prevention of VTE by early identification of patients with various risk factors. It is not time-consuming and easy for nurses to practice. Thus, it helps in instituting appropriate thromboprophylaxis and assuring patient safety.
As research dissemination effort, the findings of this study were discussed in the Clinical Meeting of the Surgical Department, to facilitate the implementation of use of 'Nurses' VTE Risk Assessment Tool' and also to bring to the notice of the surgeons on the inadequacy of thromboprophylaxis administered to the patients. A protocol on use of anti-embolism stockings was also developed by the researcher to prevent the complications related to the incorrect use of anti-embolism stockings. In addition to all these, the role of nurses in VTE prevention by implementation of measures other than mechanical and pharmacological measures cannot be excluded.
| Conclusion|| |
VTE is a potential hazard amongst surgical patients leading to significant mortality and morbidity. Fortunately, it is preventable through proper assessment and use of appropriate thromboprophylaxis. However, the various methods of thromboprophylaxis itself can also lead to other health hazards if not assessed for indications and contraindications. Nurses, being front line caregivers, are strategically placed to prevent VTE and the complications associated with thromboprophylaxis.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2]