The nurse is caring for a client who is on a mechanical ventilator. Blood gas results indicate a pH of 7.50 and a Paco2 of 30 mm Hg (30 mm Hg). The nurse has determined that the client is experiencing respiratory alkalosis. Which laboratory value would most likely be noted in this condition?

Respiratory alkalosis is defined as a deficit of carbonic acid or a decrease in hydrogen ion concentration that results from the accumulation of base or from a loss of acid without a comparable loss of base in the body fluids. This occurs in conditions that cause overstimulation of the respiratory system. Some clinical manifestations of respiratory alkalosis include lightheadedness, confusion, tachycardia, dysrhythmias related to hypokalemia, nausea, vomiting, diarrhea, epigastric pain, and numbness and tingling of the extremities. All three incorrect options identify normal laboratory values. The correct option identifies the presence of hypokalemia.

Test-Taking Strategy: Note the strategic words, most likely. Focus on the data in the question and use knowledge about the interpretation of arterial blood gas values to determine that the client is experiencing respiratory alkalosis. Next, recall the manifestations that occur in this condition and the normal laboratory values. The only abnormal laboratory value is the potassium level, the correct option.