Question

Briefly describe the difference between respiratory and metabolic pH imbalance. Describe a specific pH imbalance explaining how it is either metabolic or respiratory in nature. Discuss physiological compensation of the disorder.

Answer 1

Acid base imbalances are classified as respiratory or metabolic.Respiratory imbalances affect carbonic acid concentrations,whereas metabolic imbalances affect the base bicarbonate.Therefore acidosis can be caused by an increase in carbonic acid ie respiratory acidosis or a decrease in bicarbonate ie metabolic acidosis. Alkalosis can be caused by a decrease in carbonic acid ie respiratory alkalosis or an increase in bicarbonate ie metabolic alkalosis.Imbalances maybe further classified as acute or chronic.Chronic imbalances allow greater time for compensatory changes.

ABG Analysis

ABG values

pH 7.30 1. pH <7.4 indicate acidosis.

PaCO2 25mmHg 2 PaCO2 is low,indicating respiratory alkalosis.

HCO3 16mEq/L 3 HCO3- is low,indicating metabolic acidosis.

4 Metabolic Acidosis matches the pH.

5 The CO2 does not match ,but is moving in the opposite direction,which indicates the lungs are attempting to compensate for the metabolic acidosis.

Interpretation-This ABG is interpreted as metabolic acidosis with partial compensation.if the pH returns to the normal range ,the patient is said to have full compensation.