A patient with severe asthma has ABG pH 7.26, PaCO2 58, PaO2 60. Which findings indicate impending respiratory failure? Select all that apply.

The ABG values — pH 7.26, PaCO2 58, PaO2 60 — reveal a respiratory acidosis with hypoxemia, reflecting the patient's inability to adequately ventilate and oxygenate. Several concurrent findings confirm impending respiratory failure. Fatigue indicates the respiratory muscles are exhausted from the extreme work of breathing against severely obstructed airways; once the patient is too tired to maintain the effort, apnea and full respiratory arrest can follow. Shallow breathing reflects reduced tidal volumes consistent with muscle fatigue and worsening obstruction. A silent chest — where minimal or absent breath sounds are present — is the most ominous auscultatory finding in asthma; it indicates near-total obstruction with inadequate airflow to generate sound. A rising PaCO2 in an asthmatic is a critical warning sign: early in an attack PaCO2 is typically low due to hyperventilation, so a PaCO2 rising back toward or above normal indicates the patient can no longer compensate and is tiring. Speaking in full sentences, by contrast, indicates the patient is moving enough air to sustain speech and suggests a less critical state; it is therefore not a sign of impending failure and is not a correct answer.