Question

A cigarette vendor was brought to the emergency department of a hospital after she fell into the ground and hurt her left leg. She is noted to be tachycardic and tachypneic. Painkillers were carried out to lessen her pain. Suddenly, she started complaining that she is still in pain and now experiencing muscle cramps, tingling, and paraesthesia. Measurement of arterial blood gas reveals pH 7.6, PaO2 120 mm Hg, PaCO2 31 mm Hg, and HCO3 25 mmol/L. Based on these clinical findings, how will the kidneys compensate?

a. Conservation of bicarbonate
b. Conservation of hydrogen ions
c. Elimination of proteins in the urine
d. Retention of protein in the urine.

Answer 1

The kidneys compensate for the patient's respiratory alkalosis by decreasing the production of bicarbonate and increasing the reabsorption of hydrogen ions to lower the blood pH towards normal.

Step-by-step explanation:

The patient's arterial blood gas values are indicative of respiratory alkalosis, with a pH of 7.6, which is above the normal range (7.35-7.45), a decreased PaCO2, and normal HCO3- levels. To compensate for this, the kidneys attempt to reestablish acid-base equilibrium through metabolic compensation, which involves decreasing bicarbonate (HCO3-) reabsorption and enhancing hydrogen ion (H+) retention.

Rather than conserving bicarbonate, the kidneys will decrease the production of bicarbonate and increase the reabsorption of H+ from the tubular fluid to lower the blood pH back towards the normal range. This renal compensation helps to mitigate the effects of the respiratory alkalosis.