Q J Med 2000; 93: 663-667
© 2000 Association of Physicians
UK patients with deep-vein thrombosis can be safely treated as out-patients
From the Department of Haematology, St Peter's Hospital, Chertsey 1 Department of General Medicine, North Manchester General Hospital, Crumpsall 2 Department of Haematology, Norfolk and Norwich General Hospital, Norwich, UK
Received 12 March 2000 and in revised form 9 August 2000
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Summary |
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Deep-vein thrombosis (DVT) affects
1:1000 people, 750 cases/year in a Health Authority of average size. Prior to 1992, patients presenting with DVT were usually admitted for treatment with unfractionated heparin (UFH) over a 5-day period, but pressures on medical admissions have prompted many hospitals to review conditions which could be managed at home. Three different pilot studies commenced in 1996 at three centres in the UK. After 6 months, the protocols used were integrated into the normal care plan of the hospital. In total, 5191 patients were assessed, of whom 1347 were either venogram or dopples ultrasound positive. Overall 1138 (82%) were treated as out-patients, 75% presenting during ‘working hours’. Only 12 patients were readmitted, one with a clinically significant PE. Success was attributed to three factors: assignment of a key person as the project co-ordinator; referral of patients directly to permanent, dedicated staff, either on the Medical Admissions Unit (MAU) or the Accident and Emergency (A&E) department; and the introduction of dedicated anticoagulation nurses. In the 6-month period following initial therapy, complications were well below those in previously published studies. Most patients with DVT in the UK can be treated safely and effectively without being admitted to hospital. |
Introduction |
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Deep-vein thrombosis (DVT) affects approximately 1:1000 people, which represents approximately 750 cases/year in a Health Authority of average size.1 Recent reports have estimated the annual cost of managing DVT to be around £230m per annum.2 This figure could be substantially reduced if out-patient treatment could be shown to be safe and effective in the treatment of DVT.
The common predisposing risk factors are age over 40 years, obesity, major surgery without adequate prophylaxis (often orthopaedic), immobilization, pregnancy and the puerperium, malignancy, congestive cardiac failure, previous thromboembolism and the blood group A.3
The tendency to recurrence depends on the presence or absence of temporary or permanent risk factors, with low risk of recurrence in those with temporary risk factors such as immobility or surgery (RR at 1 year 0.45–0.58) and high risk of recurrence in those with cancer or thrombophilia (RR 1.88–2.0).3
Prior to 1992, the classic treatment for DVT was unfractionated heparin (UFH) given as an intravenous infusion over a 5-day period, followed by long-term warfarin, generally for 12–24 weeks. Currently, low-molecular-weight heparins (LMWH) are the treatment of choice.3 These are fractions obtained from UFH and have significant advantages, particularly with their once-daily regimen. They are characterized by higher bioavailability and longer half-life, and do not require laboratory monitoring.5
Patients presenting with DVT are usually admitted for treatment with LMWH, but pressures on medical admissions have prompted many hospitals to review conditions which could be managed at home, particularly in the winter months. In 1996, two studies reported the effectiveness and safety of out-patient treatment of DVT using LMWH instead of UFH.6,7 Publication of these studies coincided with a pilot study being undertaken at three centres (Norfolk and Norwich, St Peter's Chertsey and North Manchester, here called centres 1, 2, and 3, respectively) to evaluate the efficacy and feasibility of new protocols for the out-patient treatment of DVT. These protocols were subsequently adopted as standard practice.8
This study reports the ways in which three hospitals set up ‘fast track’ out-patient DVT services based on similar although not identical protocols.
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Methods |
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In each of the three centres, patients with suspected DVT were referred by their General Practitioner (GP). In centres 1 and 3, they went directly to the Medical Assessment Unit (MAU), but in centre 2, where the MAU has not yet been established, patients were referred to the Accident and Emergency (A&E) department.
On arrival during ‘working hours’, patients were given an appointment for a radiological evaluation. In centre 1, they were ‘fast tracked’ for a same-day ultrasound investigation. In centre 2, patients were ‘fast tracked’ for same-day light reflective rheography (LRR) with a same-day venogram for those with a positive LRR. Centre 3 had no facilities for same-day radiological tests, so patients were treated according to the out-of-hours protocol. This was used in all three centres, and involved daily injections of LMWH until a confirmatory test had been performed.
Patients with negative scans (ultrasound, LRR or venogram) were discharged back to the care of their GPs. Patients with confirmed thrombosis were started on warfarin and continued to have daily injections of LMWH until their INR was within the therapeutic range.
Where appropriate, the treatment was provided on an out-patient basis, although a small group was considered unsuitable for home management and was admitted for treatment. This included patients at high risk of bleeding, e.g. those with an intracerebral bleed within the last 6 months or a gastrointestinal bleed in the last month or a verified bleeding disorder. Patients with renal failure, liver failure, pregnancy or gross hypertension were treated on an individual basis. In centre 2, which had ‘hospital at home’ available as a care package, very few cases were considered not suitable for home management. In centre 1, the geographical area of referrals was almost three times that of the other two centres, which meant that difficulty in transportation also had to be taken into account.
Patients considered suitable for home treatment were informed of their diagnosis and of the management plan for their treatment. They were given pre-packaged treatment kits (made up in the Pharmacy in centre 2 and by the anticoagulant nurses at the other centres) which contained pre-loaded syringes of tinzaparin, and 1 mg and 3 mg warfarin tablets, together with instruction sheets. Before leaving hospital, patients were weighed and given the first dose of LMW heparin. Arrangements were then made for the subsequent daily injections (usually five) to be given by the District Nurses, who were contacted directly by nursing staff in the MAU and A&E. In selected circumstances, patients were taught to self-inject. At centre 2, all patients were supplied with compression hosery either from the A&E on day 1 or the anticoagulant clinic on day 3. Although they were advised to use these for 2–3 years, very few wore them after the first 6 weeks. At the other centres, hosery was only given for symptomatic relief.
After three days, patients were seen in the anticoagulant clinic, either by the Consultant Haematologist (in centre 2) or the anticoagulant nurses who had been specially employed to facilitate this mode of therapy in centres 1 and 3. In centres 1 and 3, the initial warfarin was administered according to the Fennerty charts,9 and when stable, a proportion of patients were monitored in General Practice. Centre 2, knowing that all patients would receive five days of LMWH, started warfarin at a dose that would be the most likely maintenance dose (i.e. 6 mg for older men, 4 mg for older women, 8 mg for those younger than 50), and continued to follow these patients in the hospital anticoagulation clinic.
All 1138 patients were entered onto an Excel spreadsheet and centres 1 and 2 also used anticoagulation software packages (Dawn and Hillingdon) for the complete collection of data. Patients who failed to attend follow-up, due to illness or death, were captured by the computer prompt, and notes were obtained. Causes of death were recorded.
The standard practice of warfarinization was not altered in these centres. The duration of therapy was between 3 and 6 months, unless risk factors (such as cancer or recurrent thromboembolism) required continuation beyond that period. Thrombophilia screening was carried out on every case for the first year, and thereafter only those who were ‘high risk’, i.e. those <50 years old, or with a history of recurrent thrombosis, a positive family history or a thrombosis in an unusual site.
Initially, all patients (n=99) from centre 2 were followed-up for 12 months, 3 months on warfarin and 9 months off warfarin. Centre 2 then reverted to only seeing low-risk patients at 3 months. Cancer patients were kept on warfarin with follow-up for the rest of their lives; those with positive thrombophilia screens were seen annually, or more frequently if they were on warfarin. Centres 1 and 3 contacted their patients at 3 months to document any adverse events such as bleeding. Cancer patients and those with positive thrombophilia screens followed the same protocol as centre 2.
Medical responsibility for the programme was taken by the Medical Physicians on call in the MAU at centres 1 and 3 whilst at centre 2 the Consultant Haematologists took full responsibility. The setting up of the programme at centres 1 and 2 was undertaken by a Consultant Haematologist while that at centre 3 was set up by a Respiratory Physician.
A survey was used to measure patient satisfaction and assess reaction to the way in which the diagnosis was managed and the subsequent care and treatment.
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Results |
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The centres commenced their out-patient protocols as 6 month pilot studies in 1996/97, with centre 2 starting 6 months prior to the others. As a result of their success, these were then integrated into the normal management plan of the hospital.
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In total, 5191 patients were assessed, of whom 1347 were either venogram-positive (centres 2 and 3) or Doppler-ultrasound-positive (centre 1). On average, 75% presented and were assessed during ‘working hours’. Overall, 1138 were treated as out-patients. The proportion of these patients who had isolated calf DVT was 14% overall: 65 in centre 1, 59 in centre 2 and 37 in centre 3.
Two hundred and nine patients (18%) were admitted, all from centre 1: 41 for possible pulmonary embolism (PE), 54 for extensive DVT and 51 for other medical reasons, namely abnormal blood results (18), illness due to malignancy (20), diabetes (3), chest infections (3) as well as multiple previous DVTs (5) and concurrent cellulitis (2). The rest (56) were admitted ostensibly for social reasons, because of transport difficulties that arose due to the nature of the catchment area.
Very few (18, 1.3%) of the DVTs were post-operative, because patients within 3 weeks of major surgery were excluded, and all centres were using anticoagulants prophylactically in high-risk surgery and orthopaedics.
In total, 1138 patients (82%) were treated as out-patients, and of these only 12 were readmitted (10 for investigation of possible PE of which only one was proven on the evidence of ventilation and perfusion scanning, one with thrombotic stroke which subsequently recovered and one with acute gastroenteritis). None had their management altered. 15 patients with extensive DVT were managed in the community, all from centre 2.
Using Fennerty charts to adjust the dose of warfarin meant that blood tests were done daily in the first 3 days at centres 1 and 3, and resulted in 90% of patients being in the therapeutic range by day 4. Although 10% of patients became over-anticoagulated, none had any overt bleeding event. At centre 2, the first INR performed was at the anticoagulant clinic. The different dosing schedule was chosen so that no patients became over-anticoagulated, while 90% were in the therapeutic range by day 6. This resulted in 10% requiring 1–4 extra injections of LMWH.
All patients at centre 2 presenting in 1996 were followed up for 1 year, and all had thrombophilia screening. Only four of the initial 99 patients had a positive screen, of whom only two rethrombosed, one at 8 months and the other at 18 months after therapy had stopped. Eleven had a malignancy, with eight dying within that year. Centres 1 and 3 started their pilot studies 6 months later, and followed these patients for 6 months. Following these pilot studies, and in line with published international data, subsequent patients were followed-up for 3 months.4,6,10
In terms of patient satisfaction, 70 patients at centre 1 were invited to take part in a survey. Of 56 completed questionnaires, 37 (66%) stated that they were very satisfied, and a further 19 (34%) were satisfied with the care and treatment they had received.
It was hospital policy at centre 2 to ask all patients to express their opinion of the care they received. Patients in the study were unanimously ‘satisfied’ or ‘very satisfied’, with the exception of three patients who experienced delays in waiting for venography when the machine failed to work. At centre 3, a telephone ‘hotline’ was set up for any problems to be discussed. Only two patients and two GPs used this to express dissatisfaction with the program.
In the whole study, only one patient had a clinically-significant PE. Scans were not performed to look for asymptomatic emboli. Two patients had a minor bleed while on warfarin, but none had major bleeding. Two patients died during the first week of therapy. Both of these were elderly and frail, one with co-existing dementia and the other who only had a distal DVT. Neither had a post mortem performed.
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Discussion |
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In this study, 1126 DVT patients were safely treated as out-patients, using varied methodologies. Previous studies has drawn attention to concerns that such patients being prematurely discharged, but the evidence from these three centres shows such suggestions to be unfounded.10
The particular concern about concurrent PE has been addressed by two recent publications, where LMWH (tinzaparin) has been shown to be as effective and safe as UFH in treating patients presenting with acute PE.11,12 No one with ‘non-severe PE’ died during the course of their treatment, which suggests that this group of patients, i.e. those who do not have hypotension, heart failure or syncope, could safely and effectively have been treated at home.
The success of the protocols can be attributed to three factors. First, the assignment of a key person as the project co-ordinator. This was a Consultant Haematologist in two of the Centres, and a Respiratory Physician in the third. The study suggested Haematologists to be particularly well suited to this role because of their experience in running anticoagulation clinics and in liaising with other Physicians and GPs as a routine part of their work.
The second factor was the referral of patients directly to permanent, dedicated staff, either on the MAU or the A&E. The third factor, linked with this, was the introduction of dedicated anticoagulation nurses funded either from the savings that ensued from the reduction in the number of medical beds needed or financed from ‘winter pressure’ money from the Health Authority.
At the outset there were a number of concerns about the impact of the study. Fears that the workload of the Consultant Haematologists would be unacceptably increased, were addressed by the employment of the specialist nurses. More fundamental concerns about the safety of the protocol also proved unfounded in practice, since no patient died or suffered significant morbidity as a result of the change in the initial anticoagulation practice from heparin in the hospital to LMWH at home.
The question of medical responsibility has been raised at several hospitals outside this study, and was an issue at one of the three centres. One solution was to recommend follow-up appointments for those with continuing symptoms, including those with negative radiology. At no time was funding or responsibility of the LMWH treatment devolved to the GPs, and great care was taken to engage the primary-care section in full consultation.
Using unfractionated heparin for 5 days, the cost amounts to £48.22 for the heparin, two intravenous cannulas, pump tubing and pump depreciation. This cost is increased substantially by using a buritol-giving set and by including the cost of at least six Activated Partial Thromboplastin time (APTT) blood tests. LMWH can be given without a pump and with no requirement for APTT tests at the cost of £40 per person, for 5 days. Additional savings of approximately £1800 also ensue from the ‘opportunity costs’ of cancelling booked surgical admissions if acute medical admissions do not have to be admitted to a surgical bed.
The patient surveys suggested a high degree or satisfaction with the service and did not reveal any patient anxieties. The requirement to attend as an out-patient appeared to present no particular difficulties, and very few patients required hospital transport.
In the 6-month period following LMWH therapy, the complications were well below those in previously published studies.13 We conclude that most patients with DVT in the UK can be treated safely and effectively without being admitted to hospital.
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Notes |
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Address correspondence to Dr D. O'Shaughnessy, Department of Haematology, C Level, Mail Point 008, Southampton General Hospital, Tremona Road, Southampton SO16 6YD. e-mail: kcb07{at}dial.pipex.com
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References |
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3.
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