From the Guidelines
Asthma can indeed cause respiratory alkalosis, particularly during acute asthma attacks, as a result of hyperventilation and excessive elimination of carbon dioxide from the body. This occurs when the airways narrow and become inflamed, causing difficulty breathing and triggering a compensatory increase in respiratory rate as the person tries to get more oxygen 1. The rapid breathing blows off too much carbon dioxide, decreasing its levels in the blood and raising the blood pH above normal (alkalosis). Key symptoms and signs of asthma exacerbations, as outlined in the guidelines for managing asthma exacerbations, include breathlessness, coughing, wheezing, chest tightness, agitation, increased respiratory rate, and decreased lung function as measured by FEV1, peak expiratory flow (PEF), PaO2, PaCO2, and arterial oxygen saturation (SaO2) 1.
Some important points to consider in the context of asthma and respiratory alkalosis include:
- The severity of asthma exacerbations can be categorized as mild, moderate, severe, or life-threatening based on symptoms, signs, and functional lung assessment 1.
- Treatment of asthma exacerbations focuses on addressing the underlying asthma with bronchodilators like albuterol and anti-inflammatory medications to open airways and reduce inflammation, which will normalize breathing patterns and correct the acid-base disturbance.
- As the asthma attack progresses and becomes more severe, the person may develop respiratory acidosis instead, as airway obstruction worsens and carbon dioxide retention occurs.
In clinical practice, it is essential to monitor patients with acute asthma attacks closely for signs of respiratory alkalosis and acidosis, and to adjust treatment accordingly to prevent complications and improve outcomes.
From the Research
Asthma and Respiratory Alkalosis
- Asthma is a condition characterized by airway hyperresponsiveness, inflammation, and reversible airway narrowing, which can lead to respiratory alkalosis 2.
- In acute exacerbations of asthma, poorly ventilated alveoli can lead to increased elimination of carbon dioxide, resulting in respiratory alkalemia 2.
- Respiratory alkalosis is a common problem that can affect various organ systems, and its etiologies may be related to pulmonary or extrapulmonary disorders, including hyperventilation syndrome 3.
- Asthma can cause respiratory alkalosis due to hyperventilation, which can lead to a decrease in carbon dioxide levels and an increase in pH 4.
- However, it's worth noting that asthma can also lead to metabolic acid-base disorders, such as high anion gap or non-anion gap metabolic acidosis, particularly in acute severe cases 5.
Key Findings
- The study by 2 found that in acute exacerbations of asthma, ventilation is generally increased, leading to excessive elimination of carbon dioxide and respiratory alkalemia.
- The study by 3 discussed the various facets of respiratory alkalosis, including its etiologies, metabolic abnormalities, and therapeutic approaches.
- The study by 4 highlighted the physiological effects of hyperventilation, including respiratory alkalosis, and provided suggestions for detecting and managing this condition.
- The study by 5 reviewed the acid-base disturbances in patients with asthma, including respiratory acid-base disorders and metabolic acid-base disorders.