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CHAPTER 12

Intensive Care

Andrew Gustaf Nyman
Alison Shefler

Introduction • The epiglottis is shorter, narrower, and more horizontally positioned
Injury or illness is defined as critical when one or more organ systems than in an adult.
are either in danger of failing or have begun to fail. In this situation, • The larynx is in a more anterior and cephalad position than in
the possibility of incomplete recovery or death exists. Critical care an adult.
comprises the monitoring, support, treatment, and interventions for the
organ systems in failure. Paediatric critical care not only encompasses • The trachea is smaller and narrower.
bedside management of children with severe, potentially life-threaten- • The airway is funnel shaped, with the narrowest portion at the level
ing medical or surgical illness, but also extends to providing support to of the cricoid cartilage.
the child’s family or caregivers. The challenge lies in the complex bal- Functional airway compromise results in children with decreased
ance of providing support of single or multiple organ systems in failure muscle tone in the head and neck. It may be secondary to a decreased
while at the same time minimising adverse consequences of treatment. level of consciousness and/or the effects of anaesthesia or analgesic or
This level of care is usually, but not always, provided in a dedicated sedative drugs. An inability to maintain a patent airway, even in the
paediatric intensive care environment with the capacity to offer sophis- absence of a structural abnormality, may present as great a risk as the
ticated monitoring, diagnostic and therapeutic interventions, as well as presence of anatomical obstruction.
advanced technological support for the critically ill child. When the Airway compromise may be due to or exacerbated by congenital
outcome is poor or death ensues, the critical care focus shifts to pallia- anomalies, the presence of foreign bodies, or extrinsic compression
tive and, if necessary, bereavement support. The spectrum of disease in by structures outside the airway. The most significant difference in
children differs from that of the adult population, as does the paediatric the paediatric airway compared to that of adults, and therefore a major
response to illness, surgery, or injury. Congenital abnormalities, genetic contribution to the vulnerability of the airway, is its size and diameter.
15
syndromes, inborn errors of metabolism, and toxins, as well as trauma, According to the Hagen-Poiseuille law, which relates to the flow of
including birth-related and nonaccidental injury, all influence the dif- gas, a change in the radius of the airway has the greatest effect on air
ferential diagnosis of an acutely unwell child. Regardless of the aetiol- flow. As a result, any oedema of the paediatric airway will significantly
ogy, basic principles of initial management and stabilisation should be reduce the calibre of the airway, resulting in a dramatic increase in
applied in all situations.
1,2
resistance to air flow and, consequently, the work of breathing. This
Approach to the Acutely Unwell Child is particularly important in infants, who are obligatory nasal breathers.
Respiratory failure is a common manifestation of critical illness and Nasal breathing, without any additional obstruction, doubles resistance
generally requires early recognition and intervention to prevent pro- to flow. The nares in infants and children are significantly smaller than
gression to full cardiopulmonary arrest, which carries a grave progno- in adults and can account for up to 50% of total airway resistance. With
3–9
sis. This section of the chapter therefore begins by outlining the sys- this is mind, it is important to note that simply removing secretions from
tematic approach that underpins all paediatric life support and intensive the nares may result in a dramatic decrease in the work of breathing. 15
care management of the acutely unwell child, namely, addressing the When intervention is required to establish airway patency, a stepwise
child’s airway, breathing, and circulation. 10 approach is essential. If basic manoeuvres, such as positioning the head,
Airway chin, or jaw, are insufficient, one may have to use airway adjuncts such
The goals of airway management are to overcome obstruction, promote as a Guedel oropharyngeal airway or a nasopharyngeal airway. For all
adequate gas exchange, and prevent aspiration. children who have a potential cervical spine injury, the spine should
The first priority in the assessment of a critically ill or injured child be adequately immobilised, and unnecessary manipulation should be
is to ensure a patent airway. Any compromise to airway patency, either avoided. Should previous efforts to establish an airway be unsuccessful,
structural or functional, is a potential medical emergency, and it is endotracheal intubation, laryngeal mask airway, or—rarely—surgical
important to recognise it because failure to establish or maintain the intervention in the form of a tracheostomy may be required, both to
airway can result in or worsen respiratory compromise. Respiratory establish airway patency and to maintain adequate gas exchange.
failure may, in turn, progress to cardiopulmonary arrest; thus, every Breathing
effort should be made to secure airway stabilisation in a timely manner. Acute respiratory failure is a major cause of paediatric morbidity
The paediatric airway is more susceptible to airway compromise and mortality. It accounts for approximately 30–50% of admis-
than that of adults for a number of reasons. 11–15 sions to paediatric intensive care facilities. 7,16–21 Numerous clinical
• A child’s proportionally larger head and prominent occiput result situations have the potential for progression to respiratory failure,
in neck flexion, with the potential for exacerbating upper airway reflecting the complex involvement of the respiratory system with
obstruction when lying supine. other organ systems. Diagnosis and management of respiratory
failure require an understanding of normal respiratory physiology
• The tongue is relatively large and its muscle tone is reduced. as well the pathophysiological processes occurring in acute medical
or surgical disease.