Use this scenаriо tо аnswer questiоns 36-37:You аre caring for a 5-year-old boy with a 4-day history of high fever and cough. He is having increasing lethargy, grunting, and sleepiness. Now he is difficult to arouse and is unresponsive to voice commands. His oxygen saturation is 72% on room air and 89% when on a nonrebreathing oxygen mask. He has shallow respirations with a respiratory rate of 38/min. Auscultation of the lungs reveals bilateral crackles. What assessment finding is consistent with respiratory failure in this child?