Airway suction, oxygen devices and nebuliser technique: Case

This bronchiolitic infant is hypoxaemic and tiring on low-flow oxygen, and the immediate priorities are to clear the secretions, state an oxygen target and escalate the device, and decide on inhaled therapy. Each step depends on understanding the device and the physics, not on repeating a routine. [3]

Clinical findings

The key findings are the copious secretions, the high respiratory rate, the marked recession and nasal flaring that show the infant is working hard and beginning to tire, and the SpO2 of 88 percent on low-flow oxygen that confirms he is failing the current device. The diffuse crackles and wheeze fit bronchiolitis. The reduced air entry reflects both the secretions and the small-airway obstruction. [1]

The candidate should recognise why nasal cannula is failing: it is a variable-performance device whose estimated FiO2 of 24 to 40 percent is diluted further by the infant's rapid recessive breathing, and the nasal secretions block the obligate nose-breather's airway. They should note that the infant is alert but tiring, which is the inflection point at which escalation is needed before exhaustion. [1]

Management

The first step is gentle suction. The candidate pre-oxygenates and suctions what they can see: the mouth and oropharynx with a rigid Yankauer and the nose gently, because clearing the nasal airway of an obligate nose-breather may itself raise the saturation. Each pass is limited to about 5 to 10 seconds with continuous heart-rate and SpO2 monitoring, and deep blind pharyngeal suction is avoided because it has caused iatrogenic mediastinitis. [3]

The candidate states a target SpO2 of 94 to 98 percent and escalates oxygen. Because the infant is failing low-flow oxygen, they move to heated humidified high-flow nasal cannula at 1 to 2 L/kg/min with blended oxygen, justifying the choice on the PARIS trial, which showed that high flow reduces intubation in bronchiolitis versus standard oxygen. They confirm the high flow is heated and humidified to avoid mucosal damage. [1]

For the wheeze, the candidate weighs the delivery method. For an infant who cannot reliably use a spacer, and who needs high-flow oxygen at the same time, a jet nebuliser is the practical choice, driven at 6 to 8 L/min with a sealed mask, salbutamol 2.5 mg for an infant under 5 years. They explain that only the respirable fraction of droplets (1 to 5 micrometres) reaches the lower airways, and that a calm infant breathing quietly receives far more drug than a crying one. [2]

Complications and follow-up

The complications to avoid are those of the procedures themselves. Suctioning this infant for too long or too deep risks vagal bradycardia, desaturation, and iatrogenic mediastinitis from blind pharyngeal suction. Dry, unhumidified high-flow oxygen would damage the airway mucosa and thicken secretions. A nebuliser driven too slowly or with a leaky mask wastes the dose, and a crying infant deposits the drug in the mouth. [4]

The candidate calls for senior and intensive care help early and reassesses continuously, because a low SpO2 that will not correct despite correct device therapy signals a cause to fix, not simply more oxygen. Once the infant stabilises, they wean the oxygen to the target, confirm the child holds the saturation in air or on baseline oxygen, document a clear written safety-net for the family (return for increased work of breathing, colour change, drowsiness, or poor feeding), and arrange follow-up. [1]