Acid-Base Practice Questions

Acid-Base Disturbances Overview

• Arterial blood gas (ABG) results are crucial for assessing acid-base status.
• Normal pH range is typically 7.35-7.45.

Respiratory Alkalosis

• Identified by high pH (7.45) and low Pco2 (30).
• Indicates decreased carbon dioxide, often due to hyperventilation.
• Compensation occurs when the pH normalizes, indicating the body is adjusting.

Metabolic Alkalosis

• Causes include loss of gastric fluid (suction or vomiting), excessive bicarbonate intake, and conditions like hyperaldosteronism.
• Characterized by an increase in pH due to deficit/loss of hydrogen ions or excess base (bicarbonate).
• Specifically, loss of hydrochloric acid through NG suction leads to this condition.

Metabolic Acidosis

• Occurs from loss of buffer bases or excessive acid retention (e.g., renal failure, diabetic ketoacidosis).
• Involves higher hydrogen ion concentration; loss of intestinal secretions can contribute.
• Results in a lower pH and potentially higher CO2.

Respiratory Acidosis

• Caused by hypoventilation, resulting in increased Pco2 and lower pH.
• Common in conditions that depress respiratory function.

Kussmaul's Respirations

• Characterized by abnormal depth and increased rate of breathing.
• Typically seen in metabolic acidosis, particularly diabetic ketoacidosis as the body attempts to expel CO2 to manage acidity.

Interpretation of ABG Results

• pH, Pco2, and HCO3- values must be analyzed together for accurate diagnosis.
• Conditions can be compensated or uncompensated depending on the body's ability to restore pH balance.

Risk Factors for Acid-Base Disorders

• Nasogastric tube suction leads to metabolic alkalosis.
• Ileostomy patients are at risk for metabolic acidosis due to loss of bicarbonate-rich intestinal secretions.

Example Conditions and Observations

• Respiratory alkalosis (elevated pH, decreased CO2) often results from hyperventilation.
• Metabolic alkalosis (high pH, possibly high HCO3-) can occur due to loss of gastric acids (vomiting, suction).
• Metabolic acidosis (low pH and low HCO3-) develops from various causes including severe diarrhea and diabetic conditions.
• Kussmaul's respirations indicate severe acidosis, requiring immediate assessment and intervention.

Test your understanding of acid-base balance with these practice questions. This quiz focuses on interpreting arterial blood gas results and identifying conditions such as metabolic acidosis and respiratory alkalosis. Challenge yourself to determine the correct answers and enhance your nursing knowledge!