Etiology and Clinical Manifestations of Respiratory Alkalosis

Introduction

Respiratory alkalosis is a condition characterized by a decrease in arterial carbon dioxide (PaCO₂) levels due to excessive alveolar ventilation, leading to an increase in blood pH. Understanding the causes and physiological responses is crucial in managing this disorder.

Etiology of Respiratory Alkalosis

Primary Causes

• Hyperventilation Syndrome: Increased breathing due to anxiety, pain, or psychological stress.
• Pulmonary Conditions: Conditions such as pneumonia, pulmonary embolism, and asthma may trigger hyperventilation.
• Central Nervous System Disorders: Stroke, trauma, or infections affecting the respiratory centers in the brain.
• Drug-Induced Hyperventilation: Overuse of respiratory stimulants like salicylates.
• High-Altitude Adaptation: Decreased oxygen levels stimulate increased breathing, leading to respiratory alkalosis.

Clinical Manifestations

The symptoms of respiratory alkalosis vary depending on severity and duration. They include:

• Neurological Symptoms: Dizziness, confusion, paresthesia, and seizures in severe cases.
• Cardiovascular Symptoms: Tachycardia, arrhythmias, and hypotension.
• Respiratory Symptoms: Dyspnea and chest discomfort despite increased ventilation.

Compensatory Mechanisms and Acid-Base Balance Adjustments

The body attempts to counteract alkalosis through various compensatory mechanisms:

• Renal Compensation: Decreased bicarbonate (HCO₃⁻) reabsorption to normalize blood pH.
• Intracellular Buffering: Hydrogen ions move out of cells to balance alkalinity.
• Respiratory Adjustments: Reduction in breathing rate when the underlying cause is controlled.

Conclusion

Respiratory alkalosis results from excessive alveolar ventilation and can significantly impact neurological, cardiovascular, and respiratory systems. Timely identification and intervention are essential for effective management.