Emergencies: causes and assessment

5.1 Emergencies


causes and assessment



Jeremy Raftos


There are many causes of collapse leading to the need for emergency medical intervention in the child. Table 5.1.1 lists some of the causes of common paediatric emergencies.



Table 5.1.1 Causes of paediatric emergencies

image

The following information outlines the requirements for early assessment and reassessment in paediatric emergencies. Details of the emergency care of the collapsed child are provided in the next chapter.


In approaching the critically ill child, the diagnosis is of secondary importance to:



• primary assessment, which is a structured activity, and


• timely resuscitation procedures.


The primary assessment, sometimes also known as the primary survey, follows progression through the following A, B, C, D, E steps:



• Airway


• Breathing


• Circulation


• Disability (deficiency of cerebral function), with attention to


• Exposure.


This structured approach is based on the knowledge that the brain requires a continual supply of its two main metabolites: oxygen and glucose. An airway problem, by depriving the brain of its oxygen supply, will lead rapidly to death and therefore must be corrected first. A breathing problem preventing oxygen moving into the lung and carbon dioxide out of the lung is the next priority. A circulatory problem preventing the oxygen being carried to the brain is next, and so on.


The resuscitation measures required and management of the collapsed child are described in detail in Chapter 5.2.



The primary assessment



Airway


Child and infant airways, compared with those of the adult, present particular anatomical and physiological differences that increase their susceptibility to compromise. Infants are obligate nose-breathers. Infants and small children have smaller airways and a smaller mandible, a proportionately larger tongue, and more floppy epiglottis and soft palate. The narrowest portion of their airway is below the cords at the level of the cricoid ring, in contrast to adults, where the narrowest portion is at the level of the vocal cords. The trachea is short and soft, and hyperextension or flexion of the neck may cause obstruction.


Ensuring that the patient has a patent airway is of the highest priority. In evaluating the airway a look, listen and feel approach is used.


Look carefully for movement of the chest wall and the abdomen. Note the degree to which intercostal and other accessory muscles are being used to overcome obstruction. Paradoxical movement of the abdomen may occur if there is upper airway obstruction.


Listen over the mouth and nose for air movement. Particular note should be made of inspiratory stridor, which is a sign of tracheal, laryngeal or other upper airway obstruction. In severe obstruction, expiratory sounds may also be heard but inspiratory noises will still predominate. A stethoscope should be used to listen over the trachea and in the axillae for air movement.


Finally the examiner, by placing his or her face close to the child’s mouth, may feel evidence of air movement.



Breathing


In childhood, conditions that result in respiratory compromise are the most common reason for emergency intervention, and are the major cause of a poor outcome.


As with the airway, there are important differences between the child and the adult. Children have a higher metabolic requirement. They have more immature musculature, with easy fatigability of the diaphragm, which is the major muscle of respiration. The chest wall is more compliant and the ribs are more horizontal, decreasing the efficiency of the bellows effect.


The airways in the child are proportionally smaller and therefore produce an increased resistance to air flow, especially when traumatized or inflamed. Resistance (R) across an airway is inversely proportional to the fourth power of the radius (r):



image



Thus, halving the radius increases the resistance very significantly.


Having established patency of the airway, evaluation for the presence and adequacy of breathing should follow. It is helpful to divide this into three aspects:



• effort of breathing


• efficacy of breathing


• effects of respiratory inadequacy on other organs.



Effort of breathing


Respiratory rate is age-dependent (Table 5.1.2). Tachypnoea is an early response to respiratory failure. Increased depth of respiration may occur later as respiratory failure progresses. However, it should be noted that tachypnoea does not always have a respiratory cause and may occur in response, for example, to metabolic acidosis. As the intercostal muscles and diaphragm increase their contraction, intercostal and subcostal recession develop. In the infant, sternal retraction may also occur.



Table 5.1.2 Vital signs by age

image

The ribs are horizontal in young children, in contrast to the downward slanting in older children and adults. This reduces the ‘bellows’ effect that the intercostal muscles give to the latter. In the child, the sternomastoid muscles must be recruited to raise the upper ribs further to increase ventilation.


In infants and small children, flaring of the alae nasi may be seen. It must be remembered that, in this age group, 50% of airway resistance occurs in the upper airway and flaring is an attempt to reduce this resistance. This is a late sign and is indicative of severe respiratory distress.


The effort of breathing is diminished in three clinical circumstances. These must be recognized, because urgent intervention may be required. Firstly, exhaustion may develop as a result of the increased respiratory demands. The younger child is even more prone to this due to immature musculature. Secondly, respiration requires an intact central respiratory drive centre. Conditions such as trauma, meningitis and poisoning may depress the respiratory centre. Thirdly, neuromuscular conditions that cause paralysis, such as muscular dystrophy and Guillain–Barré syndrome, may result in respiratory failure without increased effort.


Symmetrical movement of the chest should be confirmed. In the younger child the diaphragm is the main muscle of respiration; therefore, one should also look for movement of the upper abdomen.


Inspiratory and expiratory noises should be noted. Wheezing is heard with lower airway narrowing, as in asthma, often with a prolonged expiratory phase. Crepitations may be heard with pneumonia and heart failure.

Related posts:

  1. Sudden unexpected death in infancy
  2. Bone mineral disorders
  3. Resuscitation
  4. The newborn infant: stabilization and examination

Stay updated, free articles. Join our Telegram channel
Tags:
Aug 4, 2016 | Posted by in PEDIATRICS | Comments Off on Emergencies: causes and assessment

Full access? Get Clinical Tree
Get Clinical Tree app for offline access