Vital Signs and GCS

Introduction

Awareness of the normal ranges for paediatric vital signs is valuable to understand a child’s clinical picture and anticipate the need for escalation. Children’s physiology is different from adults’, and hence, different values are required to determine whether a child falls within or outside the normal range. Paediatric vital sign values are categorised depending on age.¹

The Glasgow Coma Scale (GCS) is a widely used scoring system that provides a quick, practical way of assessing consciousness levels in response to various stimuli.² The GCS was modified to form the PGCS^3,4 suitable for use in children, though both are composed of the best response to three parameters: eyes, verbal, and motor.

Vital Signs

Vital signs are a clinical measurement that reflect essential body functions, which include heart rate (HR), respiratory rate (RR), temperature and blood pressure (BP).

Physiology

Children are not simply ‘small adults’ and have different physiology from adults. From neonates to adolescents, children are still physically and cognitively developing. Consequently, paediatric vital signs are categorised according to age groups. The Paediatric Early Warning Sign (PEWS) is a well-adopted tool in many paediatric units to categorise vital signs in children.⁵ Children are incredibly good at compensating; for example, they can maintain their blood pressure for longer during acute illness; hence, hypotension is a late sign in a sick child.⁶ For this reason, other organ symptoms and signs can be used to assess circulation in children (such as reduced urine output (UO), mottled/ashen skin, pallor, cool peripheries, and altered mental state). For more detail on this, see the NICE traffic light system for identifying the risk of serious illness in children.⁷

By TeachMeSeries Ltd (2024)

Image 1: A vital signs monitor, used for continuous monitoring of observations when required.

Heart Rate

Children’s resting heart rates are generally higher than adults – the highest values being seen in neonates and decreasing with age. Children have a smaller heart, with a smaller stroke volume and a smaller amount of circulating blood volume than adults, which all increases as they continue to develop.

Cardiac output (CO) is calculated by multiplying heart rate (HR) and stroke volume (SV). This helps explain the higher heart rate seen in younger children. For children to have adequate cardiac output, their heart rate must be higher than in adults.

Respiratory Rate

A child’s respiratory rate will decrease as their lungs develop. There is less space for the gaseous exchange of oxygen and carbon dioxide, hence a higher respiratory rate in younger children.

Normal ranges

The normal values for children can be seen below in table 1.¹

Table 1: Normal ranges for paediatric vital signs. Adapted from the APLS Aide-Memoires for both boys and girls, from ALSG 6^th Edition¹

Pathophysiology

There are many reasons why a child’s vital signs could increase or decrease, falling outside of normal ranges.

Heart Rate

Increased: crying, anxiety, dehydration, fever, sepsis, pain, arrhythmias, anaphylaxis, IgE-mediated cow’s milk protein allergy (CMPA), use of medications like salbutamol. Research has shown a linear association between infant pulse rate and body temperature.⁸

Decreased: normal physiological response (during sleep and in athletes), vasovagal episode, beta-blockers, heart block, hypothyroidism.

Respiratory Rate

Increased: may be caused by lung pathology (e.g. bronchiolitis, pneumonia), metabolic acidosis (e.g. hyperventilation in diabetic ketoacidosis (DKA) or panic attacks), anaphylaxis, and sepsis.⁹

Decreased: may be caused by central respiratory depression from raised intracranial pressure (ICP), poisoning, hypothermia, encephalopathy, or imminent respiratory arrest.⁹

Temperature

Temperatures should not be used as a predictor of sepsis,¹⁰ however, a temperature <36 or >38.5 is a red flag. However, for historical fever, modalities of temperature measurement should be explored.

Fever is a sign that an immune response is occurring. The level of fever, when interpreted in isolation, does not necessarily correlate to how sick the child is. However, the exceptions to this are:⁷

• A temperature >39⁰C in infants 3-6 months old
• A temperature >38⁰C in babies <3 months old

Some fevers respond to antipyretics, whilst others don’t. The reason for this is not widely understood; however, we know that a fever is not normally dangerous for a child! Antipyretics can be given to improve symptoms for the child so that they feel better, but do not affect the body’s response to the illness (for example, to a viral infection).

GCS

As mentioned above, the GCS has been adapted for use in children to the PGCS (Paediatric Glasgow Coma Scale). The differences and similarities between the two can be seen below:

Table 2: Comparison of Adult GCS and PGCS, adapted from First Aid for free³ and British Paediatric Neurology Association⁴

*Pain in adults can be elicited by: fingertip pressure, trapezius pinch, or at the supraorbital notch

Any child with GCS <8 will require urgent definitive airway management.

It is worth noting that factors such as alcohol and drugs can ‘mask’ the true level of consciousness, especially in a head injury situation.³

NICE Traffic Light System

The NICE traffic light system for identifying risk of serious illness⁷ categorises symptoms and signs as high risk (red), intermediate risk (amber), or low risk (green), with recommendations dependent on which category a child falls into.¹¹ 

Management

If red features suggesting a severe or life-threatening cause of febrile illness are present, the child should be transferred by ambulance to A&E. These could include:

• Features of sepsis or central nervous system (CNS) infection such as bacterial meningitis/meningococcal disease, or encephalitis (see https://cks.nice.org.uk/topics/sepsis/ and https://cks.nice.org.uk/topics/meningitis-bacterial-meningitis-meningococcal-disease/)
• Features of pneumonia or severe dehydration (see https://cks.nice.org.uk/topics/cough-acute-with-chest-signs-in-children/)

If there are non-life-threatening red features, arrange an urgent (within 2 hours) face-to-face assessment (if the child was assessed by telephone) to help guide if hospital admission is necessary.

If there are amber features (with no red features), arrange a face-to-face assessment if the child was initially assessed by telephone or hospital admission, depending on clinical judgement. Consider admission if:

• Infant <3 months with suspected UTI and no alternative focus of infection (to obtain a urine specimen and initiate treatment) (see https://cks.nice.org.uk/topics/urinary-tract-infection-children/)
• No apparent underlying cause for the fever, and the child is unwell for longer than expected for a self-limiting illness
• There is significant parental/carer anxiety and/or difficulty coping due to the family/social situation

If the child can be managed at home, provide advice by one of the following methods, depending on clinical judgement:

• Advice on warning symptoms and signs and when the urgent medical review is needed (see the UK Sepsis Trust leaflet and consider giving to parents to help advise on when to seek further help)
• Arrange a follow-up appointment in primary care
• Liaise with other healthcare professionals, including out-of-hours providers, to ensure direct access for the child if further assessment is required

The child can usually be managed at home if there are green features (with no amber or red features).

If the child can be managed at home:

• Assess for and manage any underlying cause of fever if appropriate
• Consider urine dipstick and urine microscopy and culture if there is unexplained fever and no apparent focus of infection to exclude UTI
• Advise paracetamol or ibuprofen to reduce fever if the child is uncomfortable or distressed, and measures to prevent dehydration (see https://cks.nice.org.uk/topics/feverish-children-management/)
  • Advise that routine antipyretics do not reduce or prevent recurrent febrile seizures
• Provide safety netting advice on warning symptoms and signs and when the medical review is needed

References