From the Guidelines
Severe respiratory alkalosis should be managed by addressing the underlying cause, with a focus on controlled breathing techniques, and gradual correction of the alkalosis to prevent overcorrection and potential complications. This condition is characterized by an abnormally high blood pH (above 7.45) due to excessive elimination of carbon dioxide through hyperventilation 1. Treatment options may include controlled breathing techniques, such as breathing into a paper bag in conscious patients to increase CO2 rebreathing, and sedation with benzodiazepines like diazepam (5-10mg IV) or midazolam (2-5mg IV) in severe cases 1.
Key Considerations
- Identifying and treating the underlying cause of the alkalosis, whether it's anxiety, pain, sepsis, or other conditions that trigger hyperventilation, is crucial 1.
- For mechanically ventilated patients, ventilator settings should be adjusted to reduce minute ventilation, with correction occurring gradually to prevent overcorrection leading to acidosis 1.
- Electrolyte imbalances, particularly hypokalemia, should be monitored and corrected as respiratory alkalosis causes potassium to shift into cells 1.
- Severe respiratory alkalosis can lead to serious complications including tetany, seizures, cardiac arrhythmias, and decreased cerebral blood flow, making prompt recognition and treatment essential 1.
Recent Insights
A recent study published in 2018 suggests that periodic hyperventilation, as seen in central sleep apnea/hunter-cheyne-stokes breathing, may have compensatory effects in patients with heart failure, including assisting forward cardiac output and protecting the failing heart from decompensation 1. However, this does not directly impact the management of severe respiratory alkalosis, which remains focused on addressing the underlying cause and supporting the patient through the acute phase.
Management Approach
The management approach should prioritize:
- Controlled breathing techniques
- Gradual correction of the alkalosis
- Identification and treatment of the underlying cause
- Monitoring and correction of electrolyte imbalances
- Adjustment of ventilator settings in mechanically ventilated patients
- Sedation in severe cases, with options including benzodiazepines 1.
From the Research
Definition and Causes of Severe Respiratory Alkalosis
- Severe respiratory alkalosis is defined by an arterial partial pressure of CO2 <35 mm Hg with subsequent alkalization of body fluids 2.
- It is most commonly caused by disorders that increase alveolar ventilation, such as hyperventilation 2, 3.
- Respiratory alkalosis can be acute or chronic, with metabolic compensation initially consisting of cellular uptake of HCO3- and buffering by intracellular phosphates and proteins 3.
Clinical Significance and Treatment
- Severe respiratory alkalosis should be approached with a sense of urgency and be aggressively corrected, as it can cause clinically significant decreases in tissue oxygen delivery 4.
- Mild respiratory alkalosis often serves as a marker of an underlying disease and may not require therapeutic intervention, but severe cases require prompt treatment 4.
- The treatment of respiratory alkalosis depends on the underlying cause, and may involve addressing the underlying disorder or providing supportive care to manage symptoms 2, 4.
Associated Risks and Complications
- Respiratory alkalosis can lead to life-threatening complications, making it essential for clinicians to have a thorough understanding of the cause and treatment of this acid-base disturbance 2.
- Severe respiratory alkalosis can also be associated with adverse outcomes, particularly in critically ill patients, and requires careful management to prevent further complications 4.
- Certain medications, such as benzodiazepines, may contribute to respiratory problems and exacerbate respiratory alkalosis 5.