A 12-year-old client arrives with wheezing and a history of a peanut allergy. What is the most critical intervention?

In a scenario involving a 12-year-old client with wheezing and a known history of a peanut allergy, timely intervention is crucial due to the potential for an anaphylactic reaction, which can lead to respiratory distress. Administering supplemental oxygen is a critical intervention in this case because wheezing may indicate airflow obstruction and inadequate oxygenation, which are common in allergic reactions or asthma exacerbations. By providing supplemental oxygen, healthcare providers can help ensure that the child's oxygen saturation levels are maintained, preventing hypoxia and supporting respiratory function until further treatment can be initiated.

Other options may involve necessary actions in an emergency department setting; however, they do not address the immediate need for oxygenation, which is vital for the child's safety and stability in this specific situation. Oral medications, while important, may take time to exert their effects and would not provide immediate relief in a potentially life-threatening situation. Waiting without intervention or only checking vital signs does not address the urgent need for oxygen support in the presence of respiratory distress.