What compensation mechanism occurs during metabolic acidosis?

• A. Hyperventilation
• B. Hypoventilation
• C. Cardiac output increase
• D. Renal compensation

Answer: (A)

In metabolic acidosis, the body experiences a decrease in blood pH due to an accumulation of acids or a loss of bicarbonate. To counteract the acidosis, the body employs several compensation mechanisms to restore acid-base balance.

Hyperventilation is a critical response during metabolic acidosis. The respiratory system attempts to compensate for the decreased pH by increasing the rate and depth of breathing. This elevated ventilation rate helps to expel carbon dioxide (CO2), which is an acid when dissolved in blood. By removing CO2, the body raises blood pH toward a more normal level, reducing the acidity. This respiratory compensation is a rapid response and can occur almost immediately after the onset of metabolic acidosis.

While renal compensation is indeed a mechanism that occurs during metabolic acidosis, it takes longer to become effective. The kidneys will eventually increase the excretion of hydrogen ions and reclaim bicarbonate to help restore normal pH levels, but this process can take hours to days, unlike the immediate response provided by hyperventilation.

In summary, hyperventilation serves as the primary and immediate compensation mechanism during metabolic acidosis, effectively aiming to correct the decrease in blood pH through increased elimination of carbon dioxide.