The table below details criteria for assessment of severity of acute asthma attacks in children.

Levels of severity of acute asthma attacks in children

(⁶³⁹)

Before children can receive appropriate treatment for an acute asthma attack in any setting, it is essential to assess accurately the severity of their symptoms.

The following clinical signs should be recorded:

• Pulse rate
  • increasing tachycardia generally denotes worsening asthma; a fall in heart rate in life-threatening asthma is a preterminal event
• Respiratory rate and degree of breathlessness
  • ie too breathless to complete sentences in one breath or to feed
• Use of accessory muscles of respiration
  • best noted by palpation of neck muscles
• Amount of wheezing
  • which might become biphasic or less apparent with increasing airways obstruction
• Degree of agitation and conscious level
  • always give calm reassurance.

Clinical signs correlate poorly with the severity of airways obstruction.^640-643 Some children with acute severe asthma do not appear distressed.

Decisions about admission should be made by trained clinicians after repeated assessment of the response to bronchodilator treatment.

Accurate measurements of oxygen saturation are essential in the assessment of all children with acute wheezing. Oxygen saturation monitors should be available for use by all healthcare professionals assessing acute asthma in both primary and secondary care settings.

PEF measurements can be of benefit in assessing children who are familiar with the use of such devices. The best of three PEF measurements, ideally expressed as a percentage of personal best, can be useful in assessing the response to treatment.

A measurement of <50% predicted PEF or FEV1 with poor improvement after initial bronchodilator treatment is predictive of a more prolonged asthma attack.

Chest X-rays rarely provide additional useful information and are not routinely indicated.⁶⁴⁴, ⁶⁴⁵

A chest X-ray should be performed if there is subcutaneous emphysema, persisting unilateral signs suggesting pneumothorax, lobar collapse or consolidation and/or life-threatening asthma not responding to treatment.

Blood gas measurements should be considered if there are life-threatening features not responding to treatment. Arteriolised ear lobe blood gases can be used to obtain an accurate measure of pH and PaCO2.⁵⁷⁸ If ear lobe sampling is not practicable a finger prick sample can be an alternative. Normal or raised PaCO2 levels are indicative of worsening asthma. A more easily obtained free flowing venous blood PaCO2 measurement of <6 kPa (45 millimetres of mercury) excludes hypercapnia.⁵⁷⁸

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