A nurse is caring for a client with a nasogastric tube to suction who is at risk for which acid-base imbalance?

A client with prolonged NASOGASTRIC (NG) SUCTION or excessive VOMITING is at risk for METABOLIC ALKALOSIS — because they lose HYDROCHLORIC ACID (stomach acid, which contains H+ and chloride) from the stomach, raising blood pH (less acid = more alkaline). NCLEX physiological/acid-base. Also lost: potassium and chloride (risk of hypokalemia, hypochloremia). MONITOR: electrolytes, acid-base status, replace fluids/electrolytes as ordered. ACID-BASE QUICK REFERENCE: vomiting/NG suction → metabolic alkalosis; diarrhea → metabolic acidosis (loss of bicarbonate); hypoventilation → respiratory acidosis (CO2 retention); hyperventilation → respiratory alkalosis (CO2 blown off). Knowing that loss of stomach acid (vomiting/NG suction) causes metabolic alkalosis is a commonly tested NCLEX acid-base concept.