Acid-base imbalance

ACID-BASE IMBALANCE

Normal Value Range

• pH: 7.35 - 7.45
• PCO2 (Partial Pressure of Carbon Dioxide): 35 - 45 mmHg
• HCO3 (Bicarbonate): 22 - 26 mEq/L

Types of Acid-Base Imbalances

1. Respiratory Acidosis

• Results from increased PCO2 due to hypoventilation or impaired gas exchange.
• Common causes include chronic obstructive pulmonary disease (COPD), respiratory depression, or severe pneumonia.

2. Respiratory Alkalosis

• Results from decreased PCO2 due to hyperventilation.
• Common causes include anxiety, hypoxia, or fever.

3. Metabolic Acidosis

• Results from decreased HCO3 or increased acid (like lactic acid or ketones).
• Common causes include diabetic ketoacidosis, renal failure, or diarrhea.

4. Metabolic Alkalosis

• Results from increased HCO3 or loss of acid (like vomiting).
• Common causes include excessive bicarbonate intake, diuretic use, or severe vomiting.

ROME Method for Analyzing Imbalances

• ROME: An acronym to help remember the relationship of pH to PCO2 and HCO3 in different types of imbalances.
  • Respiratory: Opposite
  • In respiratory imbalances, when one value (PCO2) increases, the other value (pH) decreases and vice versa.
  • Metabolic: Equal
  • In metabolic imbalances, if the HCO3 increases or decreases, the pH moves in the same direction (increases or decreases respectively).

Regulation of Acid-Base Balance

• The regulation of acid-base balance in the body is primarily controlled by two systems:
  • Lungs: Regulate carbonic acid levels through the process of respiration, affecting the PCO2 levels.
  • Kidneys: Regulate bicarbonate levels either by retention or excretion to maintain the HCO3 levels.