Oxygen Therapy Setup

Oxygen therapy increases the amount of oxygen available for gas exchange when the patient cannot maintain adequate oxygenation independently. A low PaO₂ or SpO₂ signals inadequate oxygen transfer, but oxygen is supportive treatment: it does not remove an airway obstruction, clear pneumonia, reverse pulmonary oedema, or correct hypoventilation. Respiratory compromise can deteriorate rapidly, making timely assessment and intervention critical. The RPN first looks at the patient rather than the flowmeter: respiratory rate and pattern, depth, work of breathing, ability to speak, chest movement, breath sounds, level of consciousness, and skin or mucous-membrane colour. Accessory muscle use, nasal flaring, intercostal retractions, a falling SpO₂, exhaustion, or new confusion indicate that the patient may be moving toward respiratory failure. A saturation value is useful, but it is not the whole respiratory assessment. Oxygen can raise SpO₂ while carbon dioxide continues to accumulate in a patient who is tiring or hypoventilating. A patient who becomes drowsy or difficult to rouse despite an improved SpO₂ needs urgent reassessment of ventilation and escalation, not simply a higher oxygen flow.