Download Department of Diabetes and Vascular Medicine

Exeter Clinical Research
Standard Operating Procedure: Measuring brachial blood pressure using
an automated device.
SOP Number:
NIHRexe004GEN
Version Number & Date:
V1.1
Effective Date: 24/09/2016
24/09/2016
Review Date: 24/09/2018
Superseded Version Number & Date: PCRF/04/gen V2 10.08.12
Author:
Name: Suzette Mitchell
Position: Research Nurse
Signature:
Date: 13.08.2016
Approved by:
Name: Dr Anna Steele
Position: Senior Research Nurse
Signature:
Date: 18/08/2016
Senior Management Agreement:
Name: Gillian Baker
Position: CRF Manager
Signature:
Date: 24/09/2016
I agree that appropriate members of my workforce (as named above) have written and
approved this SOP for use in clinical research.
Page 1 of 5
SOP Number: NIHRexe004GEN
Effective Date: 24/09/2016
Version: V1.1
1. BACKGROUND:
Blood pressure (BP) may be defined as the force exerted by blood against the walls of
the vessels in which it is contained. Differences in blood pressure between different
areas of the circulation provide the driving force that keeps the blood moving through the
body. Blood pressure is usually expressed in terms of millimetres of mercury (mmHg).
The systolic pressure is the maximum pressure of the blood against the wall of the
vessel following ventricular contraction, and is taken as an indication of the integrity of
the heart, arteries and arterioles. The diastolic pressure is the minimum pressure of the
blood against the wall of the vessel following closure of the aortic valve, and is taken as
a direct indication of blood vessel resistance.
Blood pressure measures are common physiological parameters and are used for
clinical, diagnostic, and research purposes.
2. SCOPE:
This SOP applies generically to Clinical Research in Exeter, unless a trial agreement
specifically indicates that another organisation’s SOP (Standard Operating Procedures)
should be used.
3. PURPOSE:
To ensure correct and uniform measurement of blood pressure using an automated
device in projects undertaken within the ECRF (Exeter Clinical Research Facility).
4. DEFINITIONS AND ABBREVIATIONS:
BP
Lymph oedema
mmHG
SOP
Blood pressure
An accumulation of lymph in the tissues, producing swelling. This
may be congenital or due to obstruction of the lymphatic vessels by
a tumour, inflammation or injury.
Millimetres of mercury
Standard Operating Procedure
5. RESPONSIBILITIES:
It is the responsibility of staff working on projects undertaken within the ECRF to;
 Read and use this SOP when measuring blood pressure
 Use a device which is calibrated (using a mercury sphygmomanometer) every 6
months[1] and ensure batteries are changed every 3 months where appropriate
 Use the same type/model of device throughout a study
 Use the same protocol throughout a study
Page 2 of 5
SOP Number: NIHRexe004GEN
Effective Date: 24/09/2016
Version: V1.1
6. SKILL LEVEL:
All personnel should be trained by an appropriate member of staff before carrying out
this procedure.
7. EQUIPMENT:
8. PROCEDURE:
Where appropriate check patient has emptied bladder prior to measurement[2]
1. If possible measure blood pressure prior to taking blood samples
2. Explain to the patient that blood pressure is to be taken, discuss the procedure
and obtain verbal consent[3]
3. Allow the patient to rest for 5 minutes in a quiet room at ambient temperature in a
supine or seated position[2, 3]
4. For each study ensure the same patient position (sitting or supine) is used to
ensure consistency of the measurements. This eliminates any possible variation
between lying and sitting blood pressure, particularly if participants have
underlying postural hyper or hypotension. [3]
5. Ensure that tight or restrictive clothing is removed from the arm, as any restriction
can alter the accuracy of the reading.
6. Use a cuff that covers 80% of the circumference of the upper arm and not more
than 100% (see table 1 for guide).The length to width ratio of the bladder should
be approximately 2:1 [1, 2, 4]
7. Apply the cuff snugly around the upper arm
8. The cuff should be placed two to three centimetres above the elbow joint with the
indicator mark on the cuff over the brachial artery (MHRA, top 10 hints in measuring
blood pressure www.mhra.gov.uk)
9. Ensure the arm is supported either by a pillow or table at the level of the right
atrium of the heart (mid sternum) with hand relaxed and the palm upwards[2-4]
10. Instruct the patient not to speak while the cuff is inflating and deflating. You
should not talk either[2]
11. Instruct the patient not to cross their legs whilst the cuff is inflating and deflating
as this can raise the BP by 2 to 8mmHg [2]
Page 3 of 5
SOP Number: NIHRexe004GEN
Effective Date: 24/09/2016
Version: V1.1
12. Start the device according to the manufacturer’s guidelines.
13. Measure the blood pressure on the dominant arm, unless otherwise indicated,
and take subsequent readings from the same arm. Document which arm is used
for the purpose of the study.
14. Measure the blood pressure 3 times with 1-2 minutes between each reading.
15. If blood sampling occurs prior to BP measurement, if possible, use arm opposite
to the one used in blood sampling
16. If the patient has a history of carcinoma of breast, lymphoedema or limb disability,
use opposite arm to affected site.
17. Clean cuff after each participant with antiseptic wipes.
If unable to meet any criteria for blood pressure measurement as per SOP, discuss with
the PI to agree a revised procedure and design a study specific SOP. Ensure this
revised procedure is documented in the patient’s record, and is adhered to for each BP
measurement from then on, in that patient.
9. DESIRED OUTCOME:
Accurate measurement and recording of each participant’s blood pressure
10. REFERENCES:
Table 1
Indication
Small adult/child
Standard adult
Large adult
Adult thigh cuff **
Width (cm)* $
10-12
12-13
12-16
20
Length (cm)* $
18-24
23-35
35-40
42
*These ranges are derived from recommendations from the British Hypertension Society (BHS), European
Hypertension Society (ESH) and the American Heart Association
** Large bladders for arm circumferences over 42cm may be required
$ Bladders of varying sizes are available so a range is provided for each indication
References:
1. Dougherty. L., Lister. S, 2015. The Royal Marsden Manual of Clinical Nursing
Procedures. 9th Edition. Wiley-Blackwell Publishers, London.
Page 4 of 5
SOP Number: NIHRexe004GEN
Effective Date: 24/09/2016
Version: V1.1
.
2. British Hypertension Society, Blood pressure management Fact File, 2011.
www.bhsoc.org
3. Pickering, T.G., et al,. Recommendations for Blood pressure measurement in Humans:
part 1. PubMed 2005 18(3) p. 139-85.
4. British Hypertension Society Guidelines 2011, in collaboration with NICE. (WEBSITE
Hampton Medical conference Ltd.)
5. Elizabeth Martin, Oxford Medical Dictionary- 6th Edition, 2015. Oxford University Press.
Page 5 of 5
SOP Number: NIHRexe004GEN
Effective Date: 24/09/2016
Version: V1.1