Identifying Respiratory Acidosis in a Medical Emergency

A 50-year-old male is brought to the emergency department after being found unresponsive in his home. His partner reports that he has a history of chronic obstructive pulmonary disease (COPD) and was prescribed long-term oxygen therapy. Upon assessment, the nurse notes that the patient is in respiratory distress, exhibiting redness of the face and cyanosis around the lips. A capillary blood gas test reveals a pH of 7.25, PaCO₂ of 55 mmHg, and HCO₃ of 24 mEq/L. The nurse recognizes this clinical scenario suggests a respiratory acid-base imbalance. Fill in the blank with the appropriate term: The patient is experiencing __________.