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Preventing VTE

It's vital that all health care and nursing staff are aware of how to reduce the risk of a patient developing a VTE. By carrying out timely risk assessments, identifying those most at risk and carrying out preventative measures, you will be saving the lives of many of your patients. Patient education is also a very important part of preventing VTE. If a patient understands what VTE is, how it develops, and the possible consequences, they will be much more likely to take preventative measures, both whilst in hospital and after discharge.

What you can do

Whilst it's alarming that there are so many potentially preventable deaths from VTE in UK hospitals every year, it's crucial to focus on the word 'preventable'; this suggests it's possible to prevent unnecessary deaths in the future, provided certain protocols are followed. Following your risk assessment, there are a number of things that will help reduce the risk of patients who are identified at high risk of VTE, from developing VTE whilst in hospital and after discharge.

Pharmacological options

This refers to preventative measures involving medication. Patients with a high-risk of VTE, especially those having orthopaedic surgery, should be offered a form of anti-coagulant medicine (as long as they have a low risk of bleeding) to reduce the risk of developing thrombosis (blood clots). These anti-coagulant medicines may be low molecular weight heparin (LMWH), or an anti-coagulant medicine by another name. Different types of medicine may be given in different ways, including orally (unless the patient is recommended not to take anything orally, such as prior to undergoing a general anaesthetic) and via injection.

Whilst aspirin prevents blood clots in the arteries - it is used to help prevent heart attacks and strokes - it is poor at preventing blood clots in the veins and so is not recommended to prevent DVT or PE.

Mechanical options

This refers to preventative measures that are not related to medication. Anti-embolism stockings can decrease the risk of DVT. They may be used alongside anti-coagulants, intermittent pneumatic compression and/or foot pumps. Anti-embolism stockings help to prevent venous stasis (pooling of blood in the leg veins) and venous distension which can trigger formation of blood clots. Thigh length anti-embolism stockings will be the type used most frequently for surgical in-patients however anti-embolism stockings should not be used in patients with diabetes or peripheral arterial disease as both diseases narrow the blood vessels and stockings will do more harm than good.

Other options for mechanical prophylaxis include intermittent pneumatic compression devices such as compression sleeves and foot pumps. As with anti-embolism stockings, these devices must be fitted correctly for each patient and there is a video later in this section that demonstrates how stockings and intermittent pneumatic compression devices should be fitted.

There are some contra-indications for the use of anti-embolism stockings. These are:

All health care staff must be trained in the use of anti-embolism stockings and intermittent pneumatic compression devices. You need to be able to fit them onto a patient and to show the patient how to wear them correctly. You also need to check regularly that the patient is continuing to wear them, right up until he/she is normally mobile again.

Measuring a patient for anti-embolism stockings

Anti-embolism stockings must be correctly fitted to help prevent VTE. If they are too loose, they will do nothing to help prevent VTE. If they are too tight, they will act as a tourniquet, and completely stop the flow of blood in the patient’s leg. Therefore it’s vital that you measure the patient’s leg properly to ensure that you will be fitting the correct size of stocking onto each patient.

This video, kindly provided by e-Learning for Healthcare, demonstrates how health care staff should measure a patient’s legs to ensure that anti-embolism stockings, and intermittent pneumatic compression sleeves, fit correctly. To view a transcript of this video select: Measuring a patient for anti-embolism stockings (Word 26KB) or Measuring a patient for anti-embolism stockings (PDF 12KB).

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Important points to remember about measuring patients for anti-embolism stockings

Before deciding to fit anti-embolism stockings, check for any contra-indications (mentioned above), such as massive oedema (excessive swelling caused by a build-up of fluid in the tissues), arteriosclerosis or skin conditions such as dermatitis. If any contra-indications are present, you must not proceed with fitting stockings, and should instead seek advice about alternative methods of preventing VTE with that particular patient.

You will need to take three essential measurements in order to identify which are the correct size stockings to fit on a patient. The measurements may either be taken while the patient is lying down, or standing. These three measurements are:

  1. When measuring the patient’s thigh, ensure that the tape measure is positioned around the widest point. Write down the measurement.
  2. When measuring the patient’s calf, ensure that the tape measure is positioned around the widest point. Write down the measurement.
  3. When measuring the patient’s leg length for thigh-length stockings, measure from the gluteal fold to the heel. When measuring leg length for knee-length stockings, measure from the popliteal fold, behind the knee, to the heel. Write down the measurement.

Some manufacturers of anti-embolism stockings supply a size chart with their stockings. Once you have the patient’s thigh, calf and leg length measurements, you will be able to use the chart to identify which size stocking is required. It may be necessary to measure both legs, particularly where there is a significant difference in leg size.

If the patient’s thigh circumference is greater than the stocking manufacturer’s maximum circumference, it would be better to use knee-length stockings instead. If a patient is unwilling or unable to wear thigh-length stockings, preferring to roll them down to the knee, it would better to fit them for knee-length stockings.

It’s important to record the patient’s measurements, as well as the size of stocking you have fitted, onto the patient’s chart. These measurements will also help you to determine the size of intermittent pneumatic compression sleeve a patient might need, in order to use an anti-embolic pump device.

How to fit anti-embolism stockings, and intermittent pneumatic compression for a patient

This video, kindly provided by e-Learning for Healthcare, demonstrates how health care staff should fit an anti-embolism stocking onto a patient. It also demonstrates how health care staff should fit a compression sleeve onto a patient’s leg in preparation for the use of intermittent pneumatic compression. To view a transcript of this video select: Fitting a patient for anti-embolism stockings (Word 26KB) or Fitting a patient for anti-embolism stockings (PDF 13KB).

Play this video

Important points to remember about fitting anti-embolism stockings

Once you have identified the correct stocking size to use, you will need to fit it onto your patient’s leg. It’s important to follow the correct procedure carefully, to ensure that your patient’s stockings are properly fitted in order to prevent VTE.

  1. First, put your hand inside the stocking and move it down towards the ‘foot’ of the fabric (i.e. where the patient’s foot will be).
  2. Locate the ‘heel’ of the stocking – they’re often easy to identify as they may be a different colour to the rest of the stocking, or they may be made of denser fabric than the surrounding stocking area.
  3. Once you have located the heel of the stocking, take hold of it and pull it out of the stocking, so that it’s inside out.
  4. Ask your patient to put their foot into the stocking, ensuring that the ‘heel’ part of the stocking is under their heel.
  5. Make sure that the patient’s toes are not poking out of the end of the stocking, in case the elastic surrounding the hole restricts their blood flow.
  6. The hole at the end of the stocking should be underneath the foot, so that nursing staff can easily check the foot for any discolouration that might indicate a problem with blood flow.
  7. Gently roll the length of the stockings up the patient’s leg, making sure that there are no wrinkles in the fabric.
  8. Once the stockings are on properly, check that your patient feels comfortable – the stockings should feel tight and secure, but not unbearably so.

It’s important to explain to patients exactly why they need to wear anti-embolism stockings. If they understand what VTE is, how serious it can be, and how the stockings can help prevent VTE, they will be more likely to follow your instructions carefully. Tell him/her not to roll the stockings down if they can possibly help it. If the patient removes their stockings, it’s important to put them on again as soon as possible. The stockings can be washed in cool or warm water, but should not be washed in very hot water or dried on a radiator as excessive heat will damage the fabric and make them far less effective.

Important points to remember about fitting intermittent pneumatic compression

It is important that these devices are not fitted to patients with confirmed or suspected VTE.

Each of the intermittent pneumatic compression sleeves will have a label indicating which side of the sleeve needs to be placed against the back of the patient’s leg. It will also show you which end of the sleeve is the ankle end, and which end is the thigh end.

  1. First, ask the patient if you can slide the sleeve under his/her leg.
  2. Next, wrap the sleeve up, fastening the Velcro strips to each other.
  3. Once fastened, the sleeve should feel reasonably tight, but you should still be able to slide two fingers under the top of the sleeve.
  4. Attach the sleeve to the pneumatic compression machine, making sure that the connection snaps properly into place.
  5. Next, unwrap the foot cuff and ask your patient to place their heel into the strap at the back of the cuff. Fasten the foot cuff and attach it to the machine, again making sure it is properly connected.
  6. Once you’re happy that everything’s in place, tell your patient that you’re going to switch the intermittent pneumatic compression machine on. The machine will self-regulate to apply the correct pressure to the patient’s foot and leg. The patient should feel a pleasant pressure of waves going up his/her leg, as the machine encourages the flow of blood away from the foot and back to the heart. Patients fitted with a foot pump should feel deep pressure on the ball of his/her foot, similar to what they’d feel if they were walking.

Intermittent pneumatic compression and foot pump devices are useful preventative measures for VTE before surgery, and can be used alongside anti-embolism stockings post-surgery while patients are in hospital. As you did with the anti-embolism stockings, talk to your patient about intermittent pneumatic compression and foot pump devices, and how these will help prevent them from developing VTE by mimicking a walking motion, even when they aren’t able to move around themselves. Whilst the patient will be able to remove the cuff for short periods of time – to shower or have a bath, for example - it’s best if they reattach the connections quickly afterwards. Explain that they need to wear the sleeves and cuffs as much as possible to help prevent VTE.

What patients can do

One of the most important things you can do for your patient is to talk to them and their carers about VTE and what they need to do to prevent it. If a patient knows that it's important to exercise regularly in hospital and after they've been discharged, and why, then he/she will be much more likely to help in the fight against VTE. Even patients who are bed-bound can usually still do regular, gentle exercises such as ankle circling or toe stretching, and can resolve to drink more fluids in order to stay properly-hydrated. The videos in the VTE Risk assessments section provide excellent guidance on discussing VTE risks with surgical and medical patients.

Encourage your patients to drink plenty of water (unless fluid intake is restricted due to other medical conditions) and not become dehydrated during their stay in hospital. If your patients are mobile, encourage them to exercise. Where possible, encourage them to walk around as soon as possible after surgery. If they're bed-bound, encourage them to do gentle leg exercises such as leg lifts and ankle circles in bed, as soon as they're able to, and to elevate the foot of their bed or prop up their feet with a pillow to prevent their circulation from pooling.

If the patient is confined to a chair, encourage them to exercise their lower legs by raise their heels, keeping their toes on the floor, then lowering their heels again, ten times. Then raise and lower their toes ten times, keeping their heels on the floor. They need to do these exercises at least every half hour, and more often if they're able to.

After care

Before your patient goes home, make sure that he/she (and their family, partner or carer, as appropriate) is fully informed about what they can do to continue the good work of preventing VTE. Give them information leaflets on VTE and go through them together. Explain the various preventative measures they can take, such as gentle exercise every day (e.g. walking, swimming, cycling, if possible), wearing anti-embolism stockings and drinking plenty of fluids as appropriate.

Make sure your patient (and their family, partner or carer, as appropriate) understands what to do, why he/she has to do it, and the potential consequences of not doing so. The following leaflets are available online and may be useful to talk through with your patient on discharge. Some documents may be in PDF format - see how to access PDF files.