Final answer:
The nurse suspects the client with status asthmaticus has respiratory acidosis with partial compensation based on the lab results showing altered pH, pCO2, and HCO3 levels.
Step-by-step explanation:
The client arriving at the emergency department with status asthmaticus is displaying signs of a severe asthma attack. Given the lab results which show pH 7.31, a higher-than-normal pCO2, and elevated total HCO3, the nurse suspects an abnormality in the client's acid-base balance. Specifically, these results indicate respiratory acidosis with partial compensation, as the body attempts to normalize pH by increasing HCO3 levels. This phenomenon occurs because, in status asthmaticus, airflow obstruction due to inflammation, bronchoconstriction, and excessive mucus production leads to carbon dioxide retention, contributing to the acidotic state.