NCLEX Oxygenation Practice Test

Starting with a full oxygen reservoir right before the suctioning helps prevent hypoxemia. Suctioning can briefly interrupt ventilation and remove oxygen from the lungs, leading to rapid drops in oxygen saturation. By preoxygenating with 100% oxygen for about 1–2 minutes, you maximize the alveolar oxygen content and extend the safe window for suctioning, reducing the chance of desaturation during the procedure. In an intubated patient, you can deliver that 100% oxygen through the ventilator circuit or with a bag-valve mask connected to the endotracheal tube. Other options don’t directly address the risk of desaturation during suctioning: a bronchodilator helps with bronchospasm but doesn’t guard oxygenation during the procedure; increasing tidal volume isn’t indicated and can risk lung injury; humidified dry air isn’t protective and isn’t used to prevent hypoxemia during suctioning.