Management of Respiratory Alkalosis
The cornerstone of managing respiratory alkalosis is identifying and treating the underlying cause of hyperventilation, rather than directly targeting the alkalosis itself. 1, 2
Initial Assessment
Confirm the diagnosis with arterial blood gas showing pH >7.45 and PaCO₂ <34 mmHg. 2
- Measure respiratory rate and observe breathing patterns to identify hyperventilation 2
- Assess for signs of severe alkalosis requiring urgent intervention: tetany, cardiac arrhythmias, and altered mental status 1, 2
- Monitor electrolytes, particularly potassium (which increases acutely with respiratory alkalosis), calcium, and phosphate 2, 3
Etiology-Specific Treatment
Psychogenic Hyperventilation
Use rebreathing techniques (paper bag or rebreathing mask) to temporarily increase CO₂ levels. 1, 2, 4
- Provide reassurance and coaching on controlled breathing techniques to normalize respiratory patterns 1, 2, 4
- This is a diagnosis of exclusion after ruling out organic causes 5
Pain-Induced Hyperventilation
Administer adequate analgesia as the primary intervention to reduce pain-triggered hyperventilation. 1, 2, 4
Hypoxemia-Induced Hyperventilation
Administer supplemental oxygen to maintain SpO₂ 94-98% in most patients. 1, 2, 4
- For patients with COPD or other risk factors for hypercapnic respiratory failure, target lower SpO₂ of 88-92%. 6, 1, 2
Central Nervous System Disorders
Treat the underlying neurological condition (stroke, meningitis, encephalitis) as the primary intervention. 1, 2, 4
Sepsis-Related Respiratory Alkalosis
Focus on treating the underlying infection with appropriate antimicrobials. 2, 4
- Provide appropriate fluid resuscitation and hemodynamic support to address the systemic inflammatory response 1, 2, 4
Management in Mechanically Ventilated Patients
Adjust ventilator settings to normalize PaCO₂ by decreasing respiratory rate or tidal volume. 1, 2, 4
- Increase dead space if rate and volume adjustments are insufficient 1, 2, 4
- In patients with chronic hypercapnia, avoid rapid normalization of CO₂ levels to prevent metabolic acidosis. 1, 2
Disease-Specific Ventilator Targets
- For obstructive diseases: Target pH 7.2-7.4 with permissive hypercapnia if inspiratory airway pressure exceeds 30 cmH₂O. 1, 2
- For neuromuscular disease and chest wall deformity: Use higher respiratory rates with lower tidal volumes while maintaining similar acid-base targets. 1, 2
Special Clinical Scenarios
Pulmonary Hypertension
Maintain appropriate ventilation without inducing respiratory alkalosis, as excessive alkalosis can be harmful despite reducing pulmonary vascular resistance. 6, 1, 2, 4
- Consider controlled respiratory alkalosis as a therapeutic strategy specifically in persistent pulmonary hypertension of the newborn 2, 4
Chronic Respiratory Alkalosis
Address underlying chronic conditions such as chronic liver disease or heart failure that drive persistent hyperventilation. 6, 1, 2, 4
- In heart failure with Cheyne-Stokes breathing, do not aggressively suppress the respiratory alkalosis as it represents a compensatory mechanism 2
Monitoring During Treatment
Use continuous pulse oximetry to monitor oxygen saturation and avoid hypoxemia. 1, 2, 4
- Monitor arterial blood gases to assess response to treatment and avoid overcorrection 1, 2
- Watch for clinical signs of severe alkalosis including tetany, cardiac arrhythmias, and altered mental status 1, 2
- Monitor electrolytes, particularly potassium, calcium, and phosphate 1, 2
Critical Pitfalls to Avoid
Never aggressively correct respiratory alkalosis in mechanically ventilated patients with chronic hypercapnia—rapid normalization causes metabolic acidosis. 1, 2