GP mythbuster 102: Pulse oximetry and monitoring vital signs outside the GP practice setting

Page last updated: 2 September 2024

Vital signs and physiological measurements

Patients within all health and social care residential? settings are at risk of physiological deterioration. Not all deterioration can be predicted. Therefore, all patients (except for some patients at the end of their life) require more observations. This includes the taking and recording of vital signs.

Vital signs include:

oxygen saturation
heart rate (pulse)
respiratory rate
blood pressure
temperature.

This list is not exhaustive. Clinical observations in primary care settings can also include ambulatory ECG and BP monitoring. We acknowledge these include different issues and contexts. They are not included in this mythbuster.

Failing to recognise early signs of deterioration can result in poor outcomes for patients. A review found that more than half of patients who had a serious adverse event could have been identified as high-risk up to 24 hours previously.

The Nursing Times published an article explaining why measurement and recording are crucial.

Health Education England has produced video guidance for carers and care staff:

Introduction to sepsis and serious illness (YouTube)
Soft signs of being unwell (YouTube).

Oxygen Saturation (pulse oximetry)

Oxygen is carried around the body by red cells in the blood. It can be measured using a sensor usually placed on the fingertip. This is called the oxygen saturation and is a percentage (scored out of 100). It is important that the correct European accredited device is used. NHS Confederation has published guidance on medical devices accreditation as Great Britain leaves the EU.

A pulse oximeter measures how much light is absorbed by the blood. It tells clinicians how much oxygen the blood contains.

Clinical teams in hospitals and the community including GPs and Nurses use oximetry to support patients living in their own homes or care home both in the diagnosis of acute illness and longer-term monitoring of their conditions.

Many GP practices and community teams use oximetry. It supports monitoring in patients living in their own homes and residents of care homes. They are designed to support patients in primary and community health settings. They can also be used for patients who are at an early stage of disease and sent home from A&E or discharged following short hospital admissions.

NHS England has produced an easy read document explaining what pulse oximetry is. There is also an NHS at home training module for all care staff. It is free and does not need registration.

Use of pulse oximetry during Coronavirus (COVID-19)

Patients with COVID-19, typically do not respond to lower oxygen saturations by feeling as breathless, as they would do with other conditions. However, it is still a marker of how unwell a patient is and used as a criteria for hospital admission and oxygen support.

In patients with COVID-19, a decrease in the levels of saturation in response to exercise is used as a marker for severity. For example, sitting and standing or climbing a flight of stairs.

During the pandemic we have learnt more about its effects on individuals. These effects can be varied and not obvious to everyone especially in the case for older people who often develop the soft signs of illness. This has been studied and is important to detect with programmes like RESTORE 2, a deterioration and escalation tool for care/nursing homes based on nationally recognised guidance. It is important to get a complete set of physical observations. This informs conversations with health professionals.

Heart rate (Pulse)

The normal pulse for healthy adults ranges from 60 to 100 beats per minute. The pulse rate may fluctuate and increase with exercise, illness, injury, and emotions. The pulse rate may also be irregular which can indicate other heart conditions.

Pulse rates can be taken by using a heart rate monitor. NHS England have produced guidance for the general public on how to take a pulse in the wrist.

There are many pulses in the body. The main ones used by healthcare professionals are:

Carotid
Brachial
Radial
Femoral
Posterior tibial
Dorsal pedal.

The Nursing Times has published an article on taking pulse rates.

Respiration rate

Respiratory rate (RR), or the number of breaths per minute, is a clinical sign that represents ventilation (the movement of air in and out of the lungs).

The respiration rate is the number of breaths a person takes per minute. The rate is usually measured when a person is at rest. It simply involves counting the number of breaths for one minute by counting how many times the chest rises.

A change, usually an increase, in RR is often the first sign of deterioration as the body attempts to maintain oxygen delivery to the tissues.

A normal respiratory rate in adults is roughly 12 to 16 breaths per minute. Respiratory rate is an important part of a person’s vital signs and can potentially indicate more serious conditions.

If the respiratory rate is below normal, it could indicate central nervous system dysfunction. If the respiratory rate is above normal, it could indicate other underlying conditions.

Some variation in respiratory rate occurs naturally as we age. As people get older, they become more prone to diseases and organ dysfunction. Some organs are closely linked to respiratory health and can change the respiratory rate.

Blood pressure

NHS England has produced guidance on what is blood pressure. Blood pressure is a measure of the force the heart uses to pump blood around the body. The guidance states that:

Blood pressure is measured in millimetres of mercury (mmHg) and is given as 2 figures:
- systolic pressure – the pressure when the heart pushes blood out
- diastolic pressure – the pressure when the heart rests between beats

For example, if blood pressure is "140 over 90" or 140/90mmHg, it means the patient has a systolic pressure of 140mmHg and a diastolic pressure of 90mmHg.

A device called a sphygmomanometer will be used to measure the blood pressure. This usually consists of a stethoscope, arm cuff, pump and dial. Automatic devices that use sensors and have a digital display are also commonly used.

Health care professionals may request patients to record home blood pressure monitoring (HBPM). Blood pressure is recorded at specific times during the day and night over a longer period. The patient should be seated and resting.

Patients may also be asked to take part in ambulatory blood pressure monitoring (ABPM). This assesses daytime and night-time blood pressure during routine daily activities. Typically for one 24-hour period.

As a general guide:

ideal blood pressure is considered to be between 90/60mmHg and 120/80mmHg
high blood pressure is considered to be 140/90mmHg or higher
low blood pressure is considered to be 90/60mmHg or lower

ABPM daytime average or HBPM average of 135/85 mmHg or higher is also used as a diagnostic threshold for hypertension.

Temperature

The average normal oral temperature is 37°C.

Temperature can be taken with a thermometer that goes:

into the mouth
under the arm (axillary)
inside the ear (tympanic thermometer) held on the forehead or
inserted into the rectum (usually performed by a healthcare professional).

Temperatures can vary depending on which thermometer is used. Normal body temperature is slightly different for everyone and changes during the day.

A high temperature is usually considered to be 38 degrees C or above. This is sometimes called a fever.

National Institute for Health and Clinical Excellence (NICE) has produced a learning and educational resource on using the traffic light system for identifying risk of serious illness in children.

NHS England has produced guidance on high temperature (fever) in adults.

Assessing vital signs and assessment of findings is a key element of healthcare, used to indicate a patient’s health status. It is vital staff doing this feel confident in their ability to accurately record and report the findings.

The Royal College of Nursing (RCN) has published standards for assessing, measuring and monitoring vital signs in infants, children and young people. The standards give information on:

education and training
assessing and measuring vital signs
record keeping
medical devices and equipment
normal values in infants, children and young people.

Staff competency

The monitoring and measurement of vital signs and clinical assessment are core essential skills. All healthcare and social care staff recording or responding to vital sign data should be trained and understand the significance of the scores; based on local policies for responding to triggers and the clinical response required.

A clear understanding of the escalation protocols for each service area must form an element of the local induction process for staff. This understanding should be checked regularly. The clinician in charge should ensure all staff are aware of any changes.

Delegation

The General Medical Council (GMC) has produced guidance on the delegation and referral of care and treatment. This defines delegation as asking a colleague to provide care or treatment on your behalf.

The guidance states that when delegating care, the doctor must be satisfied that the person to whom they delegate has the knowledge, skills and experience to provide the relevant care or treatment. Or, that the person will be adequately supervised.

When providers delegate care they are still responsible for the overall management of the patient.

The decision whether to delegate is the responsibility of the registered professional. It is based on their professional judgement.

The registered professional has the right to refuse to delegate if:

they believe it would be unsafe to do so
they have concerns about the worker’s competence
they are unable to provide or ensure adequate supervision.

The employer is responsible for organising training before any of the delegated tasks being undertaken.

Employers are ‘vicariously’ liable for their employees. This means that provided the employee is working within their sphere of competence and in connection with their employment, the employer is accountable for their actions. It is important that the employer is involved, advised and supported appropriately in understanding and meeting their responsibilities.

Maintaining, decontamination and management of equipment

The Health and Safety Executive provides information on equipment safety and the MHRA produces guidance on managing medical devices. This includes training, maintenance and repair and decontamination.

We have published mythbusters for providers to refer to:

Organisations must have a protocol in place explaining how this is done, whether equipment is recalibrated or replaced.

It is expected that staff would clean the equipment between each patient within multi-patient settings and on return from a home care setting. Follow Gov.uk guidance on routine decontamination of reusable non-invasive patient care equipment.

After decontamination, equipment returned from residential care settings will need to be checked before it is used again, to make sure it works correctly.

When we inspect

We use these Regulations when we review if the practice is safe, effective, responsive, caring and well led. When we inspect, we look at the safety of the patient. This relates to:

We use our key lines of enquiry:

Further information

GP mythbusters

SNIPPET GP mythbusters RH

Clearing up some common myths about our inspections of GP and out-of-hours services and sharing agreed guidance to best practice.