Respiratory Alkalosis Management

Introduction to Respiratory Alkalosis

The American Thoracic Society recommends administering oxygen supplementally to maintain an oxygen saturation target of 88-92% in patients with severe respiratory alkalosis, to correct hyperventilation and improve oxygenation 1

The British Thoracic Society suggests considering non-invasive ventilation (NIV) if there are signs of muscular respiratory fatigue, alteration of mental status, or worsening acidosis, and to monitor arterial gases closely after initiating any intervention 1
For mechanical ventilation, the American Heart Association recommends a tidal volume of 6-8 mL/kg of ideal body weight 2, and adjusting PEEP to optimize alveolar recruitment and improve oxygenation, as suggested by the Society of Critical Care Medicine 3
The American Heart Association also recommends considering an inspiratory to expiratory time ratio of 1:4 or 1:5 in patients with obstructive disease 2

The European Respiratory Society recommends considering echocardiographic evaluation and specific treatment if there is suspicion of pulmonary hypertension 4
The American College of Chest Physicians suggests avoiding rapid correction of chronic respiratory alkalosis and monitoring for the development of auto-PEEP in patients with airway obstruction

The American Thoracic Society recommends serial arterial blood gas measurements to evaluate response to treatment, continuous monitoring of oxygen saturation, and vigilance for signs of respiratory fatigue or clinical deterioration 1
Hypercapnia is defined as an increase in the partial pressure of carbon dioxide (PaCO₂) above 6 kPa (45 mmHg) in arterial blood, with main mechanisms including hypoventilation alveolar or inefficient ventilation, increased dead space, increased CO₂ production, and increased CO₂ concentration in the inspired gas 5
Recommended respiratory rates include:
Indications for mechanical ventilation include:
Indication Threshold
Acidosis pH <7.35
Hypercapnia PaCO₂ >6-8 kPa
Respiratory rate >24 breaths/min despite optimal medical treatment
6
Consider non-invasive ventilation if pH <7.35, PaCO₂ ≥6.5 kPa, and respiratory rate >23 breaths/min persist after one hour of optimal medical therapy 1
Consider intubation if the respiratory rate exceeds 30 breaths/min, especially if there is severe acidosis (pH <7.25) 6
In patients at risk of hypercapnia, maintain a target oxygen saturation of 88-92% 5, and consider a permissive hypercapnia approach with pH >7.2 in chronic hypercapnia 1
In acute respiratory distress syndrome (ARDS), consider permissive hypercapnia if peak airway pressure exceeds 30 cmH₂O 1

Indication	Threshold
Acidosis	pH <7.35
Hypercapnia	PaCO₂ >6-8 kPa
Respiratory rate	>24 breaths/min despite optimal medical treatment