Respiratory distress, failure and arrest are part of the continuum of respiratory problems generating hypoxia in a child. Respiratory emergencies are one of the commonest reasons for pre-hospital emergency calls, and generate understandable anxiety in the child, and for the parents.
Respiratory distress is characterized by a child’s response to inadequate gas exchange in the lungs resulting from any condition that compromises oxygenation and ventilation.
Respiratory distress signs include: Raised respiratory rate, increased work of breathing, retractions, use of accessory muscles, including nasal flaring, and breathing may be noisy (grunting, wheezing, stridor).
Airway obstruction progresses more quickly in children due to the small size of their airways and relative elasticity of the supporting tissues. When a child with respiratory distress and increased work of breathing develops an altered appearance (quieter /less agitated/sleepy) and slow (or normal) respiratory rate consider the likelihood of respiratory failure beginning. These changes can be due to hypoxia and/or hypercarbia.
Respiratory failure occurs when a child is no longer able to compensate sufficiently and inadequate oxygenation and ventilation result in hypoxia.
Respiratory failure signs now include an abnormal appearance (agitation initially, lethargy and decreased conscious level, pallor and cyanosis as failure progresses). Respiratory rate and work of breathing are increased at first but decrease as the child’s condition becomes more severe, often associated with the ominous sign of bradycardia.
Careful assessment and intervention in cases of actual or impending respiratory failure can prevent the progression to respiratory arrest in many situations.
Beware of the child with a “normal” respiratory rate in the setting of markedly decreased air entry or significant wheeze or obstruction. This child is actually in respiratory failure.
Respiratory arrest is present when there is no effective breathing. Respiratory arrest is the most common event precipitating cardiac arrest in a child.
Specific respiratory signs include:
Allow the child to assume the position he/she finds most comfortable. Provide supplemental O2 by whatever means the child will tolerate without additional distress. “Blow-by” oxygen provides the benefit of additional O2 without distressing the child. Be calm and reassuring. Significant amounts of O2 and nebulized medication can be given in this way.
Transport promptly maintaining calm and supplemental O2.
In all cases prepare and have on hand the equipment necessary to support ventilation. This must be of the appropriate size for the age of the child.
Patients with stridor should be transported in the position that they prefer; the patient must be closely observed. Complete obstruction can occur suddenly without a prior decrease in oxygen saturation. If stridor is due to croup EPINEPHrine by nebulization can be used if the mask is tolerated. Patients with stridor should not be given Ventolin as it can worsen the upper airway obstruction. Be prepared to assist ventilation only in the event of complete obstruction. Bag valve mask can achieve gas exchange provided there is a good seal and enough pressure is generated. A two person technique may be required (one maintaining the seal the other bagging). Intubation is always difficult in these patients and should not be attempted in the field.
If the history suggests ingestion of a foreign body and there is no air movement clear the airway following the current CPR guidelines for an obstructed airway. If some air movement is occurring do not try to dislodge the foreign body as doing so could convert a partial obstruction to complete obstruction.
Patients who have significant wheezing can be given Ventolin.
Patients with severe airway obstruction due to anaphylaxis should be given EPINEPHrine IM in addition to support with bag mask ventilation.
Respiratory failure should be anticipated in all children with respiratory distress. Treatment at the scene involves the provision of O2 and assisted ventilation via bag-valve-mask at an age appropriate rate and with size appropriate equipment, followed by immediate emergency transport to ED. Only consider intubation if bag valve mask ventilation is ineffective in spite of confirmation of correct technique.