Thromboembolic disorders stand as a significant clinical concern within the United Kingdom, manifesting predominantly as Deep Vein Thrombosis ‘DVT’ and Pulmonary Embolism ‘PE’. This blog briefly explores these conditions and treatments.
Pathophysiology and Epidemiology
DVT occurs with the formation of a blood clot in the deep veins, typically of the lower extremities, which can embolise to the lungs resulting in PE. These conditions collectively represent a leading cause of morbidity and mortality. VTE is a frequent disease, affecting more than one million people in Europe each year (Cohen 2007), and nearly 10 million people worldwide (Khan 2021).
Clinical Manifestations and Diagnosis
The clinical manifestations of thromboembolic disorders such as DVT and PE are often insidious and can vary greatly in severity and presentation. DVT primarily presents with signs and symptoms localised to the affected limb, including unilateral leg pain, swelling, and redness. The affected area may also feel warmer to the touch compared to the non-affected limb. In some cases, surface veins may become more prominent as collateral circulation develops. However, it's important to note that some DVT cases may be
asymptomatic, particularly in the early stages.
PE, which often results from a dislodged DVT, can present with a sudden onset of dyspnoea, chest pain (which may worsen with deep breathing, known as pleuritic pain), tachypnea, and tachycardia. In severe cases, patients may experience signs of right heart strain, hypoxia, syncope, or even sudden death. Symptoms can also include haemoptysis or fever depending on the extent and location of the emboli.
Due to the non-specific nature of these symptoms, especially in the early stages, the diagnostic process is crucial and often involves a combination of clinical assessment, risk factor evaluation, and objective testing. The UK follows guidelines set by NICE, which recommend using a two-level DVT Wells score to assess clinical probability followed by appropriate imaging, typically compression ultrasonography for DVT and computed tomography pulmonary angiography (CTPA) for PE. D-dimer testing is also a valuable tool.
D-Dimer
D-dimer testing is a blood test that is commonly used to help rule out the presence of an inappropriate blood clot (thrombus). When a blood clot dissolves in the body, it produces fragments known as D-dimers. Elevated levels of D-dimers in the blood can be a sign of active blood clotting and are often found in conditions such as DVT, PE, and disseminated intravascular coagulation (DIC).
Risk Factor Stratification
Thromboembolic disorders are multifactorial, with risk stratification encompassing genetic predispositions, lifestyle factors, and medical history, including recent surgery and malignancy.
Thrombosis UK:-
“The most common risk factors for thrombosis are:
Hospitalisation for illness or surgery
Major surgery, particularly of the pelvis, abdomen, hip, knee
Severe trauma, such as a car accident
Injury to a vein that may have been caused by a broken bone or severe muscle injury
Hip or knee replacement surgery
Cancer and cancer treatments
Contraceptive pill for birth control in particular those that contain oestrogen, such as the pill, patch or ring
Pregnancy, (including the six weeks after the baby is born)
Hormone therapy (HRT), which contains oral oestrogen
A family history of blood clots
Obesity
Long-term bed rest
Long periods of inactivity including sitting for long period of time, especially with legs crossed”
Management Strategies
The cornerstone of DVT and PE management is anticoagulation, aiming to prevent clot propagation and secondary embolisation. NICE guidelines advocate for the initial use of low molecular weight heparin, followed by long-term anticoagulation with vitamin K antagonists or direct oral anticoagulants, tailored to individual patient profiles (NICE, 2020).
Post Thrombotic Syndrome
Post-thrombotic syndrome (PTS) is a long-term complication that can occur after a deep vein thrombosis (DVT). The symptoms of PTS are due to chronic venous insufficiency and damage to the veins that occurred during the initial thrombosis.
Here are the common symptoms of post-thrombotic syndrome:
Pain: This can range from a dull ache to intense pain in the affected limb, often worsened with standing or walking and relieved by elevation.
Swelling: Persistent swelling of the affected leg, often worsening throughout the day and with prolonged standing.
Skin Changes: This may include discolouration (often a reddish or brownish hue), eczema, and in more severe cases, the skin may appear shiny and tight.
Venous Ulcers: In severe cases, especially if left untreated, the increased pressure and damage to the skin can lead to venous ulcers, which are difficult to heal wounds, usually located near the ankle.
Varicose Veins: New or worsening varicose veins can be a symptom of PTS.
Heaviness or Tiredness: The limb may feel unusually heavy or tired, particularly after long periods of standing or towards the end of the day.
Itching or Tingling: Some people may experience a sensation of itching or tingling in the affected limb.
Cramping: Leg cramps may occur, especially when moving or stretching.
Stain et al (2005) followed 406 patients after their first symptomatic DVT for about 60 months to establish risk factors of PTS and its impact on venous thrombotic disease. The results showed that PTS developed in 43.3% of patients (176 out of 406), with severe PTS being rare (1.4%). The study identified proximal DVT as the strongest risk factor for PTS, with an odds ratio (OR) of 2.1. Male gender and elevated D-dimer levels were also found to be weaker risk factors. Interestingly, genetic factors such as Factor V Leiden, Factor II G20210A, or high Factor VIII levels did not confer an increased risk of PTS.
Additionally, the study found that patients with PTS had an increased risk of recurrent venous thromboembolism. The cumulative probability of recurrence at 4 years was 7.4% among patients with PTS compared to 1.6% among patients without PTS. The presence of PTS was associated with a 2.6-fold increased risk of recurrence. The study concluded that proximal DVT, male gender, and high D-dimer levels are independently associated with the development of PTS in patients with a first DVT, and patients with PTS are at an increased risk of recurrent venous thromboembolism.
Legal Issues
The legal implications primarily revolve around medical and nursing negligence claims. These implications can significantly affect healthcare providers, institutions, and patients.
Below are some key legal considerations related to VTEs:
Duty of Care: Healthcare practitioners and providers have a duty of care to their patients, which includes properly diagnosing and treating conditions such as VTEs. Failure to diagnose or delay in treatment of DVT or PE can lead to severe complications or death and may be considered a breach of this duty.
Informed Consent: Patients must be informed about the risks of VTE, especially when they are undergoing procedures or treatments that may increase the risk of clotting (e.g., surgery or certain medications). Failure to properly inform and obtain consent from the patient can lead to legal claims.
Standard of Care: The management of VTE must meet the accepted (reasonable) standard of care, which is typically based on clinical guidelines. This includes proper risk assessment, prophylaxis for at-risk patients, and timely treatment. Deviations from the standard of care that result in harm to the patient can lead to allegations of negligence.
Documentation: Accurate and detailed documentation of patient assessments, risk factors, treatments, and communications is crucial. Inadequate documentation can hinder the defence in a legal claim.
From a nursing perspective alone, as expert witnesses we often get asked to provide an opinion in cases where there has been a failure to assess risk, administer and apply prophylaxis meds/aids, failure to recognise and escalate a deteriorating patient.
By way of example, we provided evidence in a litigated negligence case involving a 55-year-old lady who suffered a cardiac arrest because of a DVT and PE. Following review of the papers, we identified that there had been two significant breaches of duty. Firstly, the patient was over 100kg, and she had not been prescribed a sufficient dose of prophylactic low molecular heparin. Secondly, there had been a failure to recognise her deteriorating condition and to escalate prior to her arrest.
Conclusion
The management of thromboembolic disorders in the UK is informed by a robust evidence base and structured clinical pathways. Continuous professional development and patient engagement are critical to optimising care and outcomes.
The legal implications emphasise the importance of diligence, proper assessment, and adherence to clinical guidelines in the management of VTEs. Healthcare practitioners should be aware of the legal risks and work towards
minimising them through quality care, application of clinical guidelines, continued education, and effective communication with patients.
References:
A.T. Cohen, G. Agnelli, F.A. Anderson, et al. "Venous thromboembolism (VTE) in Europe. The number of VTE events and associated morbidity and mortality." Thromb. Haemostasis, 98 (4) (2007), pp. 756-764
F. Khan, T. Tritschler, S.R. Kahn, M.A. Rodger. "Venous thromboembolism." Lancet, 398 (10294) (2021), pp. 64-77
National Institute for Health and Care Excellence (NICE). "Venous thromboembolic diseases: diagnosis, management and thrombophilia testing." [NICE Guideline No. NG158]. https://www.nice.org.uk/guidance/ng158
Thrombosis UK website. https://thrombosisuk.org/