Download How to measure blood pressure manually

Art & science clinical skills
How to measure blood
pressure manually
Rushton M, Smith J (2016) How to measure blood pressure manually. Nursing Standard. 30, 21, 36-39.
Date of submission: October 14 2014; date of acceptance: February 5 2015.
Rationale and key points
This article aims to help nurses to measure blood pressure (BP)
manually using an aneroid sphygmomanometer.
BP measurement is an essential clinical skill, and nurses must
be competent in performing this procedure and taking
accurate readings.
Nurses should be aware of manual BP measurement techniques
and understand the patient and environmental factors that may
result in inaccurate readings that could compromise patient care.
Nurses should regularly undertake manual BP measurement to
ensure they remain competent to perform the procedure.
Reflective activity
Clinical skills articles can help update your practice and ensure it
remains evidence based. Apply this article to your practice. Reflect on
and write a short account of:
1. How reading this article will change your practice.
2.Further learning needs to extend your professional development.
Subscribers can upload their reflective accounts at: rcni.com/portfolio.
Preparation and equipment
The nurse should explain to the patient that their
blood pressure (BP) needs to be measured. The
nurse should gain their informed consent.
The nurse should ensure that the appropriate
equipment is available and in good working
condition. This includes:
– A sphygmomanometer (working and
calibrated).
– A stethoscope.
– An appropriate-size BP cuff (British
Hypertension Society 2009) (Table 1).
– Bactericidal soap or bactericidal alcohol
hand gel.
– Detergent wipes (no alcohol).
– An observation sheet or early warning score
chart to record BP.
The nurse should know how to feel for the
radial and brachial pulses before undertaking
the procedure.
Authors
Procedure
Melanie Rushton Adult lecturer, University of Salford, Manchester,
England.
Joyce Smith Adult lecturer, University of Salford, Manchester, England.
Correspondence to: [email protected], @ RushtonMel
1. Wash your hands using bactericidal soap and
water or bactericidal alcohol hand gel.
2. Ask the patient or visually check if they have
had any trauma or surgery to their arm or have
an intravenous infusion in progress. If they
have, or if there are any contraindications, use
the other arm. If it is not possible to use either
arm, the thigh can be used by applying a thigh
cuff to the mid-thigh area.
3. Ensure the patient is relaxed and seated
comfortably, with their back supported and feet
uncrossed and flat on the floor.
4. Ensure the BP cuff is the correct size for
the arm (British Hypertension Society
2009) (Table 1).
5. Check that the patient’s arm is not restricted
by any tight clothing. Support the arm with a
pillow, ensuring that it is level with the person’s
heart (midsternal level).
6. Wrap the BP cuff around the patient’s bare arm.
The cuff should be positioned 2-3cm above the
brachial artery (Figure 1).
7. Ask the patient not to talk during the procedure.
Keywords
aneroid sphygmomanometer, blood pressure, clinical procedures,
clinical skills, vital signs
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36 january 20 :: vol 30 no 21 :: 2016
NURSING STANDARD
TABLE 1
Blood pressure cuff sizes
Indication
Bladder width
and length (cm)
Arm circum­
ference (cm)
Small adult/child
12x18
<23
Standard adult
12x26
<33
Large adult
12x40
<50
FIGURE 1
SCIENCE PHOTO LIBRARY
SCIENCE PHOTO LIBRARY
Correct position of the cuff
FIGURE 2
Taking a radial pulse
FIGURE 3
Position of stethoscope over the brachial artery
SCIENCE PHOTO LIBRARY
8. Locate the radial pulse (Figure 2). Inflate the
BP cuff by pumping the cuff bulb, until the
radial pulse can no longer be felt. Note the
reading on the dial. This figure is the estimated
systolic pressure.
9. Deflate the BP cuff completely and wait for
15-30 seconds.
10. Palpate the brachial artery to ensure the correct
placement of the stethoscope. Place the centre
of the stethoscope bell over the brachial artery
(Figure 3).
11. Inflate the cuff again to 20-30mmHg above the
predicted systolic BP.
12. Deflate the cuff slowly at a rate of 2mmHg per
second (British Hypertension Society 2006)
listening for Korotkoff sounds – often described
as whooshing, pounding, swishing or thudding
sounds. As you deflate the cuff, note when the
loud thudding occurs; this is the systolic BP.
These sounds will gradually change and become
muffled, eventually disappearing. At this point,
record the number on the sphygmomanometer;
this is the diastolic BP. In some patients
with hypertension, there may be a notable
auscultatory gap in the sounds, this is a period of
diminished or absent Korotkoff sounds during
the measurement, and should be reported.
13. Deflate the cuff fully once no further sounds can
be heard and remove it from the patient’s arm.
14. If you need to recheck the patient’s BP, wait one
to two minutes before proceeding.
15. Inform the patient that the procedure is finished.
16. Wash your hands using bactericidal soap and
water or bactericidal alcohol hand gel.
17. Clean the bell and diaphragm of the
stethoscope and the cuff with a detergent wipe.
18. Record the BP reading clearly on the observation
sheet or early warning score chart. Compare
the measurement with previous results. Inform
medical staff if there are significant changes or
if this is required in accordance with the early
warning scoring system.
19. Calculate and document the mean arterial
pressure using the formula in Box 1. The mean
arterial pressure is the amount of pressure
(British Hypertension Society 2009)
NURSING STANDARD
january 20 :: vol 30 no 21 :: 2016 37 Art & science clinical skills
required by the body to ensure that all organs
receive an adequate blood supply (Marieb 2013);
the normal range is 70-105mmHg.
Evidence base
BP recording is essential to establish baseline
measurements, which can provide vital information
about a patient’s health and are central to diagnosis,
monitoring and treatment of a range of conditions.
In the past, staff may have relied on automated BP
measuring devices. However, the use of these devices
can be problematic, because of inaccurate readings
and shortages of appropriate equipment (Alexis
2009). The accuracy and reliability of these devices
has been questioned, particularly in patients with
cardiac arrhythmias (Cork 2007). The Medicines
and Healthcare products Regulatory Agency
(MHRA) (2013) refers to manual BP measurement
as the ‘gold standard’. It raises concerns about
an over-reliance on electronic devices and the
de-skilling of healthcare professionals in manual
techniques. The British Hypertension Society
(2009) does not make recommendations regarding
manual or electronic measurement of BP, however it
emphasises the importance of using the appropriate
cuff size to ensure an accurate BP reading.
In some clinical areas, for example critical care,
arterial catheters are used for more accurate and
constant measurement of BP in critically ill patients.
However, it is important that all nurses are skilled in
performing manual BP measurement. Heinemann
et al (2008) found that automated BP measurement
devices can be used with some confidence to record
systolic BP in most adults, but there was some
variation observed when recording diastolic BP.
The accuracy of BP measurement is ensured by
the use of appropriate equipment that is in good
working order, and consideration of factors related
to the patient and environment that may affect BP
readings. This includes selecting the correct sized
cuff (British Hypertension Society 2009), ensuring
the bladder tubing does not have any cracks or
faults (Smith and Roberts 2011), and ensuring the
correct positioning and preparation of the patient;
they should be rested to avoid anxiety. It is also
important to acknowledge that patient factors such
as age, weight and diet can affect BP.
If postural hypertension is suspected, the
patient may require a sitting and standing BP
BOX 1
Calculating the mean arterial pressure
Mean arterial pressure = systolic blood pressure +
(2 x diastolic blood pressure)/3
38 january 20 :: vol 30 no 21 :: 2016
(Wallymahmed 2008). Postural hypotension is
defined as a drop in BP of >20/10mmHg. The
prevalence of postural hypertension increases
with age because the baroreflex mechanisms
that control heart rate and vascular resistance
decline with age. Other causes of hypotension
include long-term neurological conditions such
as Parkinson’s disease and drugs that affect reflex
control, such as antidepressants and alcohol.
The Nursing and Midwifery Council (2010)
identified the measurement of BP as an essential
skill that all nurses must be able to undertake, both
manually and using electronic devices. There has
been an increase in the measurement of BP using
a manual sphygmomanometer, with healthcare
organisations reporting a reduction in the number
of deteriorating patients and cases of unexpected
cardiac arrest as a result of increased awareness of
the signs of patient deterioration (Snow 2011).
Automated BP monitoring equipment should not
be used on patients with a high or a low BP, since
diastolic BP measurements have been found to be
incorrect and unreliable (Heinemann et al 2008).
Automated devices are also not suitable for patients
with abnormal heart rhythms or weak pulses (Cork
2007, MHRA 2013). Fallon (2015) discussed the
inaccuracies of BP recordings for patients with
atrial fibrillation or an irregular heart rhythm and
the difficulty in determining a definite end point for
diastolic BP, since automated devices have not been
validated for use in patients with arrhythmias.
Nurses should regularly undertake manual
BP measurement to ensure they are competent to
perform the procedure and take accurate readings.
Whichever device is used for measuring BP, it must
be validated, regularly maintained and recalibrated
according to the manufacturer’s instructions
(Fallon 2015) NS
Disclaimer: please note that information provided by Nursing
Standard is not sufficient to make the reader competent to
perform the task. All clinical skills should be formally assessed
at the bedside by a nurse educator or mentor. It is the nurse’s
responsibility to ensure their practice remains up to date and
reflects the latest evidence.
USEFUL RESOURCES
Dougherty L, Lister S (2011) The Royal Marsden
Hospital Manual of Clinical Nursing Procedures.
Eighth edition. Wiley-Blackwell, Chichester.
National Institute for Health and Care Excellence
(2011) Hypertension in Adults: Diagnosis and
Management. Clinical guideline No. 127. NICE, London.
Stergiou GS, Kollias A, Destounis A, Tzamouranis D
(2012) Automated blood pressure measurement
in atrial fibrillation: a systematic review and
meta-analysis. Journal of Hypertension. 31, 11,
2074-2082.
NURSING STANDARD
References
Alexis O (2009) Providing
best practice in manual
blood pressure measurement.
British Journal of Nursing. 18,
7, 410-415.
British Hypertension Society (2006)
Blood Pressure Measurement.
tinyurl.com/nb737wj (Last accessed:
January 8 2016.)
British Hypertension Society (2009)
Blood Pressure Measurement: With
Manual Blood Pressure Monitors.
tinyurl.com/nrlqdl2 (Last accessed:
December 17 2015.)
Cork A (2007) Theory and
practice of manual blood pressure
measurement. Nursing Standard.
22, 14-16, 47-50.
Marieb EN (2013) Essentials
of Human Anatomy and
Physiology. Tenth edition. Pearson
Education, Essex.
Fallon N (2015) The challenge
of measuring blood pressure
accurately. British Journal of
Cardiac Nursing. 10, 3, 132.
Medicines and Healthcare products
Regulatory Agency (2013) Blood
Pressure Measurement Devices.
tinyurl.com/puxemy9 (Last
accessed: December 17 2015.)
Heinemann M, Sellick K, Rickard C,
Reynolds P, McGrail M (2008)
Automated versus manual blood
pressure measurement: a randomized
crossover trial. International Journal
of Nursing Practice. 14, 4, 296-302.
Nursing and Midwifery
Council (2010) Standards for
Pre-Registration Nursing and
Education. Annexe 3: Essential Skills
Clusters and Guidance for their Use.
tinyurl.com/oqel3jq (Last accessed:
December 17 2015.)
Smith J, Roberts R (2011) Vital
Signs for Nurses: An Introduction
to Clinical Observations.
Wiley-Blackwell, Chichester.
Snow T (2011) Manual checks for
deterioration helps trust cut cardiac
arrests. Nursing Standard. 25,
42, 10.
Wallymahmed M (2008) Blood
pressure measurement. Nursing
Standard. 22, 19, 45-48.
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