GUIDELINES FOR DOPPLER ULTRASOUND

Transcription

1 Trust Guideline All Sites GUIDELINES FOR DOPPLER ULTRASOUND All healthcare professionals must exercise their own professional judgement when using guidelines. However any decision to vary from the guideline should be documented in the patient records to include the reason for variance and the subsequent action taken. Lead Clinician(s): Jackie Stephen Haynes Consultant, Lecturer & Practitioner in Tissue Viability Lead Director(s): Sandra Rote Director of Clinical Development and Lead Executive Nurse Ratified by: SW PCT R&B PCT WF PCT Adopted by Worcestershire Primary Care Trust Board: May 2006 June 2006 July 2003 March 2007 This Policy should not be used after end of: May 2009 Links into Healthcare Standard: Links into PCT aim: Domain 2 Clinical and cost effectiveness Aim 6 Clinical and cost effectiveness Impact Analysis (Race Equality) June 2006 Impact Analysis (Mental Capacity Act) THIS DOCUMENT MUST NOT BE PHOTOCOPIED PLEASE NOTE THAT ALL CLINICAL GUIDELINES ARE AVAILABLE ON

2 CONTRIBUTION LIST Key individuals involved in developing the document Name Designation Original Organisation Jackie Stephen Haynes Consultant, Lecturer and Practitioner in Tissue Viability. Worcestershire Primary care trusts Rosie Callaghan Tissue Viability Nurse Specialist for Nursing SWPCT Homes Jane Hipwell District Nurse Team Leader R&B PCT Amanda Cimarosti Leg Ulcer Specialist Nurse R&B PCT Lisa Blick Community staff nurse R&B PCT Lyn Cox Practice Nurse, Churchfields R&B PCT Cheryl Tilt Sister Lickey ward, POWCH R&B PCT Pippa Humble District Nurse Team leader, Rubery, R&B PCT Julie Shaw District Nurse Team leader WF PCT Pauline Farmer District Nurse Team leader WF PCT Lynn Dodd, Staff Nurse, Wyre Forest Community Unit WF PCT Lorraine Wallace Staff Nurse, Wyre Forest Community Unit WF PCT Jo Dodd District Nurse Team leader. Evesham SWPCT Mary James District Nurse Team leader SWPCT Bridget Gibson District Nurse Team leader Broadway SWPCT Lynne Moule District Nurse Team leader Malvern, SWPCT Pat Adcock District Nurse Team leader, Knightwick SWPCT Jo Bayliss, District Nurse Team Leader, Pershore SWPCT Sylvia Jackson District Nurse, Tenbury SWPCT Denise Moore District Nurse Team leader, Ombersley SWPCT Nicola Ross District Nurse Team leader SWPCT Margaret Murcott Community Staff Nurse. Upton-on Severn SWPCT Roz Kabani, Community Staff Nurse, Haresfield House SWPCT Surgery Sharon Freeman Community Staff Nurse. Malvern. SWPCT Debbie Keelor Sister Malvern community Hospital, SWPCT Mandy Price Staff Nurse Pershore Community Hospital SWPCT Sue Collett Staff Nurse Tenbury Community Hospital SWPCT Circulated to the following individuals for comments Name Designation Original Organisation Carol Clive Infection control Nurse WSSA Guideline for Doppler Ultrasound WPCT Page 2 of 11

3 GUIDELINE FOR DOPPLER ULTRASOUND CONTENTS PAGE NO 1. 0 Introduction and background Staff competency Scope of policy Selection of probe size Guideline on undertaking Doppler Ultrasound Guideline for interpreting typical Doppler Waveforms Doppler Ultrasound Guideline for Repeat Doppler Ultrasound- ulcer present Guideline for repeat Doppler Ultrasound-ulcer healed Guideline for interpretation of the Doppler Ultrasound results Evidence Base Audit & Outcome measures Compression Hosiery 12 Guideline for Doppler Ultrasound WPCT Page 3 of 11

4 1.0 Introduction Christian Doppler, an Austrian 19 th Century Physicist and mathematician stated that the frequency of a wave-form varied according to the velocity of the object. This has since been successfully transformed into a portable continuous wave Doppler, used to establish both the pulse wave-form and the systolic blood pressure. This sound is measured in Hertz (Hz) and a frequency of 1 Hz is a sound vibration that occurs once every second. Doppler ultrasound uses a frequency of one million Vibrations every second 1 megahertz or MHz, (Keachie1992). Doppler ultrasound is used to detect velocity and location of blood flow in both arteries and veins and is used to record a Resting Pressure Index (RPI) also known as Ankle Brachial Pressure Index (ABPI). Ankle brachial pressure index compares the traditional systolic reading with the ankle systolic reading and determines the arterial blood flow to the feet. These recordings are expressed as a ratio: Doppler ultrasound is an essential part of holistic leg ulcer assessment (Jones 2000) and is needed to ensure that the appropriate treatment pathway is chosen (RCN 1998, Vowden & Vowden 2001). It is an important element of the assessment process, but must not be judged independently. In conjunction with a holistic assessment the Doppler ultrasound can help to inform the differential diagnosis. It can be utilised to exclude arterial disease and identify those patients for whom compression is suitable and those patients with impaired arterial flow who should be referred to the vascular surgeon for revascularisation. Assessment should involve both legs regardless of whether only one limb is ulcerated (Davies 2001, Vowden& Vowden 2001). Doppler ultrasound should be utilised as an aid to the differential diagnosis of leg ulceration, being of equal importance to performing a holistic assessment. The equation for determining the ABPI is : Highest Ankle Systolic Pressure mmhg Highest Brachial Systolic Pressure mmhg = Ankle Brachial Pressure Index Doppler ultrasound should always be undertaken in conjunction with a holistic approach. 2.0 Staff competency Care of patients with leg ulceration should be undertaken by a health care professional trained in leg ulcer management (R.C.N.1998). Doppler ultrasound should be undertaken by staff who are assessed as being clinically competent and confident to undertake this test. It is essential that all practitioners receive adequate training and supervision before using Doppler ultrasound and that they are aware of their professional accountability (Hislop 1997, Morison & Moffatt 1994 and Ray et al 1994, Vowden & Vowden 2001) Guideline for Doppler Ultrasound WPCT Page 4 of 11

5 3.0 Patient Application All patients who present with a leg ulcer or are at significant risk of developing a leg ulcer and are able to tolerate the performance of the test. 4.0 Selection of probe size The most commonly used Doppler Ultrasound is made by Huntleigh Diagnostics. They have a range of probe sizes, and the rule of thumb is the lower the frequency the deeper the optimum range, the larger the transducer head. 2MHz 4MHz/5MHz - Has the optimum range of 3-15 cm - Has the optimum range of 1-8 cm for deep vascular studies. 5MHz is ideal for deep vessels and oedematous limbs. 8MHz/10MHz - Has an optimum range of 2mm-4cm and 8MHz is ideal for ABPI on average sized limbs. To assess arterial and Venous blood flow a frequency of 5-8 MHz is required. Ankle pressures should always be recorded before applying a regime of compression bandaging. Failure to do this can lead to tissue necrosis and amputation. High compression bandaging should never be used on patients with a pressure index of less than 0.8. (R.C.N & SIGN 1998, Vowden & Vowden 2001) N.B A.B.P.I. readings> can suggest calcification of the arteries therefore compression bandaging should not be applied. 5.0 Guideline on undertaking Doppler Ultrasound. N.B. This should only be undertaken following a holistic assessment PROCEDURE based on Morison et al (1998), Morison & Mofatt (1994),Vowden & Vowden (2001). Select the appropriate equipment: Mini or multi Dopplex, correct probe transducer, correct size Blood Pressure cuff, padding (to ensure conformability of cuff) and appropriate ultrasound gel and tissues. Guideline for Doppler Ultrasound WPCT Page 5 of 11

6 Explain the procedure to patient. It is important to involve patients at every stage of the assessment process ( Davies 2001) Whenever possible, lie the patient flat for at least 10 minutes, in a warm room, making the patient comfortable with no pressure on the proximal vessels). Carser (2001) has highlighted that this may not be necessary and that a short period of activity may be needed. However further research is needed and is not yet promoted as best practice If the patient is unable to lie flat the result will be affected, therefore this must be noted on the assessment form. Undertake a pulse and blood pressure recording. Cover any open area with film or film dressing. Carefully examine the foot and palpate the dorsalis pedis and posterior pedis pulses. Recording Brachial Pressure Place appropriate sized cuff around patients upper arm. Blood pressure should be below 140/ 85 mmhg for most people and less than 140/80 for patients with diabetes. (Ramsey et al 1999) Apply conducting gel over brachial artery. Hold Doppler probe (not stethoscope) at angle locate the pulse, do not press down as the pressure may obliterate a signal. Inflate cuff until signal disappears then slowly release. The point at which the signal returns is the Brachial Systolic Reading. Repeat on the other arm and again record the highest reading. Use the higher of these two readings to calculate the A.B.P.I. Ankle Systolic Pressure Cover the ulcerated areas with a sterile towel, cling film or non-adherent dressing. Place appropriate size cuff around the ankle above the Malleoli. It is important to place the cuff correctly - placing the cuff at a higher level to avoid the ulcer may give an abnormally high reading. (If placed higher than the malleoli, document this.) Identify 3 foot pulses if possible i.e. anterior tibial, posterior tibia1 and peroneal pulses. Apply conducting gel over pedal space. Guideline for Doppler Ultrasound WPCT Page 6 of 11

7 Place probe at 45 over anterior tibial or dorsalis pedis pulses and gently move until a pulsatile signal is detected. The posterior tibial or peroneal pulse should then be recorded (care should be taken not to record the same artery twice). Inflate the cuff - until the signal disappears. Slowly release the cuff until the signal returns, then record and repeat the process for the other foot. Record the highest ANKLE systolic pressure. Calculate the Ankle Brachial Index by dividing the highest ankle pressure by the highest brachial pressure ~ use pressure grid index provided in leg ulcer assessment guideline. It can be beneficial to use headphones in noisy surroundings or when the pulse is difficult to locate in patient with arterial disease. It may be necessary to allow for refilling times for each pulse, alternating the pulses may be necessary as shown: 1. Right anterior tibial 2. Left anterior tibial 3. Right posterior tibial 4. Left posterior tibial 5. Right peroneal 6. Left peroneal CAUTION Failure to identify arterial signals at the ankle, despite careful examination using a Doppler ultrasound, require a specialist vascular opinion as soon as possible. Repeatedly inflating the cuff, or leaving the cuff inflated for prolonged periods can cause the ankle pressure reading to fall by producing a hyperaemic response. If the pulse is irregular as in atrial fibrillation) it may be difficult to measure the systolic pressure as it can vary markedly from beat to beat. Artificially high readings may be obtained in: Patients with diabetes due to calcification of medial lining of the artery which renders the vessel incompressible patients with renal disease patients with gross oedema Guideline for Doppler Ultrasound WPCT Page 7 of 11

8 IF IN DOUBT SEEK A MEDICAL OPINION. 6.0 Guideline for interpreting typical Doppler Waveforms The Doppler ultrasound will give an audible sound, which may also be analysed graphically. In the absence of disease (normal) the wave form is triphasic.. Biphasic waveforms indicate mild disease The waveform becomes more monophasic as arterial disease progresses. More complex analysis of the data can be used to obtain flow velocities and an estimate of the severity of any stenosis. 7.0 Guideline for Repeat Doppler Ultrasound- ulcer present All patients should have a Doppler ultrasound repeated at 3 monthly intervals (Simon et al 1994) or sooner if Increased pain (especially at night) Claudication Unable to comply with compression General medical condition deteriorates Deterioration of leg ulcer 8.0 Guideline for repeat Doppler Ultrasound-ulcer healed All patients should have a repeat Doppler ultrasound every 6 months, they should be remeasured for fitting of hosiery, be given further supplies of emollient and health promotion advice given. 9.0 Guideline for interpretation of the Doppler Ultrasound results ( See leg ulcer assessment guideline for Doppler ultrasound assessment chart) 1.3 and above Refer to diabetic/ vascular specialist Normal arterial flow safe for compression. 0.9 Indicates a mild effect to arterial flow safe for compression. 0.8 Is the lowest level at which high compression can be safely applied. Guideline for Doppler Ultrasound WPCT Page 8 of 11

9 0.7 Indicates significant arterial disease is present and reduced compression may be used under medical/specialist supervision. Routine vascular referral. 0.6 and below Severe peripheral vascular disease requiring urgentattention. (Vowden, P. & Vowden, K and RCN 1998) Guideline for Doppler Ultrasound WPCT Page 9 of 11

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11 10.0 Evidence Base Carser, D. (2001) Do we need to reappraise pour method of interpreting the ankle pressure index? Journal of Wound Care. March, Vol 10 No3 pp59-61 Davies, C. (2001) Use of Doppler Ultrasound in leg ulcer assessment. Nursing standard. July 18/Vol 15/No44. Pp72-74 Hislop, C. (1997) Leg ulcer assessment by Doppler Ultrasound. Nursing Standard. 11, 43, Pp49-54 Jones, J. (2000) The use of holistic assessment in the treatment of leg ulcers. British Journal of Nursing. 9, 16, Keachie, J. (1992) Making sense of Doppler Ultrasound. Nursing Times. 88,10. Pp54-56 Morison, M.& Moffatt, C. (1994 ) A colour guide to the assessment and management of leg ulcers. Mosby publishing, 2nd edition London. Morison, et al (1998 ) A colour guide to the assessment and management of leg ulcers. Mosby London. Ramsey, L.E, Williams,B., Johnstone, B.G. McGregor, G.A.et al (1999) Guidelines for managing hypertension. Report of the British Hypertension Society. Journal of Human hypertension Vol 13 pp British Hypertension Guidelines. Ray, S. et al (1994). Reliability of ankle/brachial pressure index measurements by junior Doctors. British Journal of Surgery. 81, 2, pp R.C.N. (1998) The management of patients with venous leg ulcers. Clinical Practice Guidelines. London Simon, D.A.Freak, L. Williams, I.M. & Mc Collum, C.N.(1994) Progression of arterial disease in patients with healed leg ulcers. Journal of Wound Care. 3 (4) pp SIGN (1998) The care of patients with chronic leg ulcers. SIGN secreteriat, Edinburgh. Vowden, K. & Vowden, P (1996) Hand held Doppler assessment for peripheral arterial disease. Journal of Wound Care. 5, 3. Pp Vowden, P. & Vowden, K. (2001) Doppler assessment and ABPI: Interpretation in the management of leg Ulceration. World Wide wounds Audit & Outcome measures An annual audit will be undertaken with the assistance of the Clinical Governance Dept of notes of random selection of patients with active leg ulceration. Guideline for Doppler Ultrasound WPCT Page 11 of 11