2.2 Child development: The history of a developing evidence base and its impact on system
2.2.1 Physical differences
The physical differences between children and adults have been described from universally accepted stages of neonate, infant, toddler, preschool child, school age child and adolescent (Hogan, 2007). These stages are important to understand in order to know when clinical signs at specific ages, such as the blood pressure or heart rate, are normal or abnormal.
Body proportions: The head of a neonate and infant accounts for approximately 20% of the
total body surface area (TBSA), whereas an adult‘s head is approximately nine percent of the TBSA. Another example of different body proportions is seen in neonates, infants and young children, the legs in these age groups accounting for less of the TBSA in children than in adults. These TBSA facts are important in conditions such as burns, when fluid management is needed. In burns, the TBSA needs to be estimated and the differences in TBSA need to be accounted for because adult-based assessments are inaccurate when used in children and could result in inaccurate fluid delivery. Neonates and infants also have a greater surface area to body mass which can affect their ability to maintain body temperature. This is compounded by less
subcutaneous fat and their immature body mechanisms that control shivering and sweating, and, if not taken into account, can result in hypothermia much more quickly than seen in adults
(Macfarlane, 2006).
Respiration: Another example of physical differences between adults and children is that up until
six weeks of age infants are obligatory nose breathers, that is they must breathe through their noses (Kopelman, 2003). In fact, some infants may primarily breathe through their noses until
20 they are five months old (Palmer, 2001). Nose breathing can only affect a neonate or infant‘s ability to breathe effectively if the nostrils become blocked for example, from a cold with mucous, which might lead to significant respiratory distress. The breathing mechanism is also different in infants and young children. Adults breathe in by the diaphragm falling in conjunction with the intercostal chest muscles lifting the rib cage. Infants and young children, up to approximately the age of six, have immature chest muscles and therefore the diaphragm is the principle muscle used for breathing (Callahan, 2009). This is important to know because anything which causes gastric distension in young children can cause the diaphragm to be upwardly displaced, thereby reducing the amount of air inhaled (Inaba & Boychuk, 2002). The authors report this scenario to be common in paediatric trauma and can be relieved by inserting a nasogastric tube to
decompress the air in the stomach. Neonates and infants also have less than 10% of the number of alveoli in their lungs compared to adults (Johnson & Keogh, 2010). The amount of alveoli reaches similar numbers in the child by the age of eight but they are relatively smaller in size. This means that the respiratory reserve that young children have is limited causing them to tire easily and making them more prone to a respiratory arrest if they are unwell.
Cardiac function: Infants do not have the capacity to increase their stroke volume; that is, the
amount of blood released from the left ventricle with each contraction (Shiel & Stöppler, 2008) because their myocardium is less compliant than that of adults. Thus, the only way infants can increase their cardiac output is by increasing their heart rate. However, this can also lead to exhaustion when they are not well (Macfarlane, 2006). Other factors having a significant impact on children include: blood sugar levels (BSLs) and glycogen stores, which are lower in infants and children. If they are injured or unwell the BSL can drop significantly causing starvation to the cells (Sanders, 2007).
Maturity of organs: As a result of the immaturity of their internal organs, children are at greater
risk of harm in the hospital setting due to the way they metabolise medications (Kyle, 2008). Therefore, they need medications which are calculated according to the weight of the child (Kelsey & McEwing, 2008; Sredl, 2006). Knowledge of pharmacokinetics in children is needed because certain drug groups adversely affect children much more than adults (Sredl, 2006). Morphine is an example of such a drug, as it is metabolised and excreted more slowly in children, and which if not monitored appropriately will cause bradypnoea, a low breathing rate that can lead to a respiratory arrest (Hain, Miser, Devins & Wallace, 2005). It is not only pharmacokinetics in infants and children which RNs need to understand but also the added risk from fluid overload
21 from common hospital interventions such as intravenous ( IV) therapy (London, Ladewig, Ball & Bindler, 2007). If the amount or rate of fluid given is not carefully calculated and checked against the weight/ height of the child, children can get fluid overload much more quickly than adults due to the smaller circulating volume and are at increased risk from conditions such as pulmonary or cerebral oedema (Gillespie, Seidel & Symons, 2004).
Central nervous system: As children develop physically, there is an increase in the gross and
fine motor skills. Gross motor skills include walking, running and balance whilst fine motor skills include the use of hand-eye coordination such as picking up objects and drawing (Ireton, 1992). This development occurs in conjunction with the growth of the central nervous system (CNS). At birth the CNS is approximately 25% of the size of an adult. By one year of age, the CNS is approximately 50% developed and by the third birthday, the CNS is approximately 80% fully developed (Callahan, 2009; Macfarlane, 2006). Gross and fine motor development milestones are the same for all children but are achieved at different rates. While there are broad
standardised parameters for learning to walk independently, various children learn to walk at different ages and stages in their own specific timeframe (Kyle, 2008). For example, on average, many children are walking with varying degrees of assistance by one year of age (Glasper & Richardson, 2011).
Children also develop their language skills at various specific points but usually, by 18 months of age, children can say simple sentences and make their needs known (Sheridan, 1985). Kylie (2008) reports that toddlers repeat words and they can understand many more words than they can say. Although young children can use and understand many words, it is still important to use age-appropriate language (Day & Levitt-Jones, 2009; Glasper & Richardson, 2011). For young children, age appropriate explanations are important as by 12 months of age, even though infants can only say approximately four words, they can understand more than 100 words (Devitt & Thain, 2011). By the age of two, toddlers can say 50 words and obviously understand many more (Sheridan, 1985). Moreover, the ability to understand language rapidly increases and between the ages of three to four, children have a vocabulary of several thousand words (Berk, 2008). Thus young children can understand some age appropriate explanations. They also have some comprehension of emotions conveyed by the tone of voice used. For example, even young toddlers can recognise emotions such as annoyance conveyed in the tone of voice an adult uses (Whitehead, 2007).
22 Hence, it is not only the content of what is said which is important when communicating with young children, but also the tone of voice used (London, et al., 2007). They further explain the importance of using a soothing tone coupled with age-appropriate language as this can relieve anxiety. It can also help the child understand what is required of them by the health care staff as even young toddlers respond to sound and praise when they have cooperated. Furthermore, London, et al. contend that the repetition of stories can help promote a sense of stability in unfamiliar environments such as hospital wards. Accordingly as children may be frightened by their need for health care, using appropriate language builds trust and helps the child to understand the experience of hospitalisation (Glasper & Robertson, 2011).
In addition, whereas adults can often explicitly tell nurses if they think something is amiss, young children cannot since their perception of self and their language skills may not be developed enough to identify and/ or acknowledge a change in health status. Although young children cannot always say when they are unwell or explicitly explain how or in what way they are unwell, many experienced RNs working within paediatrics undoubtedly have acquired a sound
knowledge of the signs and symptoms of disease and alterations in children‘s vital signs. But, as Gill (2006) maintains, there is more to understanding of disease processes and the effects of treatment in paediatrics than just knowing about vital signs or stages of childhood development.
Gill (2006) reiterates the need for nurses to recognise how children and their families are affected by acute and chronic conditions and to recognise the psychological impacts that disease/ illness and treatment can have on children and their families. Even children with chronic conditions who have been hospitalised many times before need the reason for each admission to be established. Children will not necessarily relate hospital experiences with their own health but may associate them [the hospital] with a relative; this may have been fearful for them as, for example, the
hospital death of a relative they may have witnessed. Therefore accurate communication with the child and the family is of vital importance (Potts & Mandleco, 2012).
In addition, RNs should be aware of the potential for increased stress on families when a child is sick. If one parent stays in hospital with a sick child and the other parent has to care for the rest of the family at home, this may affect a variety of other family attributes, such as the family‘s income, the relationship of the parents with any other children and the way in which parents are able to rest due to the noisy hospital environment. A child being admitted to hospital can also
23 have an impact upon the amount of nutrition their parents receive which in turn, can affect their parents‘ mood or their resilience (GOSH, 2008).
Another stressor for parents may be how best to prepare their child for any forthcoming
admission to hospital. Hockenberry and Wilson (2011) illustrate how it is often left to the parents or carers to prepare children for hospitalisation yet parents often do not do this because they think the child will not understand the procedures, and/ or it will be too stressful for the child, and/ or the parents do not have sufficient understanding themselves to explain it to the child. Parents‘ levels of anxiety will be transmitted to their children and therefore, the more relaxed a parent is, the more relaxed their child is likely to be (Potts & Mandleco, 2012). Hence, paediatric RNs should be cognisant of all these factors and yet flexible in the face of what may appear to be ‗difficult‘ parents or siblings. They need to try to identify ways for these stressors to be minimised. For example, the RN could develop a routine for the child patient or suggest getting an extended family member to stay with the hospitalised child (GOSH, 2008). Understanding and creatively addressing the stress families face when a child is ill can help lessen the burden for families when they have a sick child who needs in-patient care.
Acquiring a sophisticated understanding of child physical and psycho-social development, including language, cognitive, behavioural and moral development, is important for paediatric RNs. Attainment of this knowledge not only facilitates detection of any abnormalities in
development (Sheridan, 1985) but helps ensure that children are kept as safe as is possible from the risk of acquiring other illnesses whilst in the hospital (Hockenberry & Wilson, 2011). There are a variety of theories which help explain these concepts.