Metabolic acidosis

Definition

Metabolic acidosis is a condition characterized by an excess of acid in the body or a loss of bicarbonate, resulting in a decrease in blood pH. This imbalance can occur due to various factors such as renal dysfunction, excessive acid production, or loss of bicarbonate from the gastrointestinal tract. The body's mechanisms to restore normal pH levels are crucial, as they directly relate to the regulation of acid-base balance and the ability of the kidneys to compensate for these disturbances.

5 Must Know Facts For Your Next Test

1. Metabolic acidosis can be caused by conditions like diabetic ketoacidosis, renal failure, and lactic acidosis, which all lead to increased acid production or decreased acid elimination.
2. A low blood pH (below 7.35) is a key indicator of metabolic acidosis, and this condition can lead to various symptoms like fatigue, confusion, and shortness of breath.
3. Compensatory mechanisms include increased ventilation to blow off CO2 and renal adjustments that increase bicarbonate reabsorption or hydrogen ion excretion.
4. In cases where metabolic acidosis is chronic, the body may adapt over time, but if severe and acute, it can lead to serious complications such as shock or death.
5. Treatment for metabolic acidosis may involve addressing the underlying cause, administering bicarbonate in severe cases, or using fluids and electrolytes to restore balance.

Review Questions

• How does metabolic acidosis affect the body's pH level and what are the physiological responses involved in restoring balance?
  • Metabolic acidosis leads to a drop in blood pH below 7.35 due to an accumulation of acids or a loss of bicarbonate. In response, the body activates several physiological mechanisms to restore balance, including increased respiratory rate to exhale more CO2 and thus reduce acidity. The kidneys also play a vital role by adjusting bicarbonate reabsorption and hydrogen ion excretion to help return blood pH toward normal levels.
• Discuss how renal compensation works in metabolic acidosis and why it is critical for maintaining acid-base homeostasis.
  • Renal compensation is essential in metabolic acidosis as it involves the kidneys adjusting their function to manage acid-base balance. The kidneys respond by increasing the reabsorption of bicarbonate while excreting more hydrogen ions into the urine. This process helps mitigate the effects of excess acid in the body and is vital for long-term regulation of blood pH. Without effective renal compensation, the risk of severe acidosis increases significantly.
• Evaluate the potential consequences of untreated metabolic acidosis on overall health and bodily functions.
  • Untreated metabolic acidosis can lead to severe health complications including cardiovascular instability, impaired respiratory function, and neurological issues. The acid-base imbalance can affect enzyme activity and disrupt cellular metabolism, leading to decreased oxygen delivery to tissues. Prolonged acidosis can result in shock or organ failure if not addressed promptly, making early detection and intervention crucial for patient outcomes.

Related terms

bicarbonate:

A crucial buffer in the blood that helps maintain pH levels by neutralizing excess acids.

anion gap: The difference between measured cations and measured anions in serum, used to help diagnose different types of metabolic acidosis.

renal compensation: The process by which the kidneys adjust the excretion or reabsorption of acids and bases to help correct pH imbalances.