Cathy Taylor, MSc, BSc, Dip N, CHS (HV), RGN, is nursing tutor, health visiting, University of Wales, Swansea.
Pyrexia is commonly defined as an abnormal increase in body temperature (Casey, 2000) and a diagnosis of fever is usually made when the temperature is elevated above 38 degsC. Walsh and Edwards (2006) found that parents’ knowledge about normal body temperature and the temperature that indicates fever is poor.
Parents often experience anxiety when a child’s temperature is elevated and the phenomenon of ‘fever phobia’ has been identified, where parents have unsubstantiated fears about the complications associated with fever (Crocetti et al, 2001).
Pathophysiology of fever
Pyrexia usually occurs as a response to an infection but there are other causes and these can include trauma, surgery and reactions to vaccinations.
Temperature is regulated by the thermoregulatory centre in the hypothalamus in the brain where core body temperature is set near 37 degsC. However, if infection occurs phagocytes (white blood cells) ingest bacteria and produce chemicals called cytokines. Injured tissues and macrophages also stimulate the production of cytokines.
Cytokines act on the thermoregulatory centre that in turn produces prostaglandins, which act to reset the core temperature at a higher level. Heat is generated and the metabolic rate (the rate at which the body uses energy) increases.
This increase in temperature is thought to inhibit the growth of bacteria. The heart rate also rises and the patient may have a rapid pulse that increases the delivery of white blood cells to the site of infection. Antibodies and T-cell proliferation is also increased.
The physiological response results in a number of clinical symptoms in infants.
These include the following:
- Crying and discomfort;
- Increase in heart rate and blood pressure.
Shivering occurs as muscles contract and relax to generate heat and a chill can occur as thermoreceptors in the skin are stimulated and cause vasoconstriction thus preventing heat loss from the skin. Once the body temperature has reached a new higher level these symptoms cease.
A fever can therefore be considered a beneficial physiological response to an infection. Infants and young children are particularly susceptible to fever because of their small body size, high ratio of surface area to body weight and reduced amount of subcutaneous fat.
Febrile convulsions can occur in young children if their body temperature rises above 38.5 degsC. This response is associated with fluid and electrolyte imbalance, shivering and rigors. If a convulsion lasts for longer than 4-5 minutes parents should seek medical assistance. Investigation and treatment are important with the aim of bringing the body temperature back down to normal range.
These three methods are commonly used to measure a child’s temperature in the home:
- Digital probe thermometer (replacing the mercury thermometer);
- Tympanic thermometer;
- Thermometer strips (these measure skin temperature and the reading is approximate).
Some parents do not own any of these devices (Walsh and Edwards, 2006) and rely on visual and behavioural changes to identify the presence of pyrexia.
Disagreement and debate continues (even among professionals) on the most appropriate devices to use (Rush and Wetherall, 2003), as well as optimal sites for successful measurement (Impicciatore et al, 1997).
Parents can access information and advice from NHS Direct as well as local health professionals to find out which method best suits their circumstances. For example, parents may find the use of thermometer strips (that can be placed on the child’s forehead), an easier and effective method of taking a child’s temperature at home.
The treatment of fever and febrile illness with antipyretic medications such as paracetamol and ibuprofen is common. However, the actual therapeutic benefits of such treatment are often overestimated and misunderstood.
Walsh and Edwards (2006) suggest that parents should consider reducing pyrexia with medication if it is:
- Higher than 39 degsC and it is associated with discomfort;
- Higher than 40 degsC; l Causing the child to become irritable or miserable or if she or he appears to be in pain.
Paracetamol, is an analgesic with antipyretic effects and it is usually considered as a first- line treatment for pain and fever (Chandler, 2003). If normal therapeutic doses are administered, adverse effects are rare. The main benefit of paracetamol is that it can be given to very young infants.
Ibuprofen differs from paracetamol in that it provides additional anti-inflammatory properties. It also has a longer interval of 6-8 hours between doses and can be useful for controlling pain and fever overnight.
Ibuprofen cannot be given to infants under six months of age and should be avoided in children with asthma as it can cause bronchoconstriction and exacerbate symptoms (Prodigy, 2006). It can be administered at the same time as paracetamol where paracetamol alone has not been effective in managing the pyrexia.
Alternating paracetamol and ibuprofen is another reported method of managing and controlling fever in children. However, the actual effectiveness of multiple regimens has not been fully evaluated and currently remains under scrutiny (Erlewyn-Lajeunesse, et al, 2006). Prodigy does not recommend alternating medication as there is a danger that parents may become confused about which was the last medicine that was administered (Prodigy, 2006).
Prescribers should inform parents about the correct dosage, strength, route and maximum dose for any antipyretic drug. This will enable them to assess how effective the medication has been and may assist them in their decision to seek further medical assistance if the child continues to be unwell. For example, Prodigy (2006) recommends giving babies of three to 11 months 2.5-5ml of a 120mg/5ml suspension of paracetamol every four to six hours, while 12-16 year olds should take one to two 500mg tablets every four to six hours.
Common physical methods of controlling temperature
Tepid sponging is often used by parents to reduce symptoms of fever (Walsh and Edwards, 2006) but the clinical benefits of this practice have been questioned (Casey, 2000). Casey (2000) suggests that such sponging may even cause additional discomfort as the body will attempt to compensate by shivering causing vasoconstriction of the skin’s blood vessels and therefore generating more heat.
Removal of clothing can be helpful in reducing body temperature and gentle fanning can help to make the child more comfortable. The child should also be encouraged to drink fluids to replace those lost through sweating.
Sources of information and support for parents
The National Service Framework for Children encourages patients to treat their children at home but it is also essential that they seek medical advice when necessary. Kai (1996) highlighted the fact that parents often face the dilemma about whether or not to consult their GP during a child’s illness and may have feelings of powerlessness and helplessness.
Chandler (2003) suggests that medical advice should be sought if a child has a fever, if she or he is under six months old and has additional symptoms, for example diarrhoea and vomiting.
If the pyrexia remains high in the older child and there is little or no response to antipyretic medication, medical attention is also recommended particularly if symptoms persist for longer than 72 hours.
This practical information may be helpful in offering guidance for parents and may give them permission to consult with healthcare practitioners, not only for treatment but also for reassurance, further education and advice. This may lead to more effective use of healthcare services and resources.
The role of primary healthcare providers in pyrexia
Many parents may have received conflicting information about pyrexia from other parents, friends, television, magazines and the internet. It is essential that primary care practitioners aim to empower parents in order to help them to make effective healthcare decisions about their children.
Traditionally, health education has focused on the provision of educational materials such as leaflets and booklets in an attempt to improve knowledge and skills. This on its own is often found to have a limited effect (O’Neill-Murphy et al, 2001). However, it can be enhanced and reinforced by verbal discussion and demonstrations within the home, in clinic visits or even in community groups such as mother and toddlers sessions.
In order to assess parental requirements, a bottom-up approach is beneficial to find out what advice and skills they may find useful to manage their child’s pyrexia at home. This can often be facilitated by primary healthcare providers and supplemented by other services such as NHS Direct, community children’s services and nurse-led clinics.
Parents require up-to-date knowledge and skills to successfully manage the health of their children at home. By working in partnerships with parents, nurses in hospital and primary healthcare settings are fundamental in providing support and enabling parents to be responsive to their children’s healthcare needs.