From the Guidelines
Respiratory alkalosis is primarily caused by hyperventilation, which leads to excessive elimination of carbon dioxide from the body, and the most significant cause of hyperventilation is anxiety or panic attacks, as evidenced by a study published in the American Journal of Respiratory and Critical Care Medicine 1.
Causes of Respiratory Alkalosis
The main causes of respiratory alkalosis include:
- Anxiety or panic attacks, which trigger rapid breathing
- High fever, which increases respiratory rate
- High altitude exposure, where lower oxygen levels stimulate breathing
- Severe pain, causing rapid breathing as a stress response
- Certain medications like salicylates (aspirin) that directly stimulate the respiratory center
- Medical conditions such as pulmonary disorders (pneumonia, asthma, pulmonary embolism), central nervous system disorders (stroke, meningitis), sepsis, liver failure, and pregnancy due to hormonal changes
- Mechanical ventilation with excessive settings can also induce this condition
Pathophysiology
Respiratory alkalosis occurs because when breathing rate increases, more carbon dioxide is expelled, reducing carbonic acid in the blood and raising pH above the normal range of 7.35-7.45, as explained in a study published in Thorax 1.
Symptoms
Symptoms of respiratory alkalosis may include:
- Lightheadedness
- Tingling in extremities
- Muscle cramps
- In severe cases, tetany or seizures
Treatment
Treatment focuses on addressing the underlying cause rather than the alkalosis itself, though in acute cases, breathing into a paper bag can help retain some carbon dioxide, as mentioned in a study published in the Journal of Clinical Sleep Medicine 1.
Recent Findings
A recent study published in 2018 found that hyperventilation can be a compensatory mechanism in patients with heart failure, and that it can help improve cardiac output and reduce the severity of symptoms 1. However, this study does not change the primary cause of respiratory alkalosis, which is still hyperventilation, often triggered by anxiety or panic attacks.
From the Research
Causes of Respiratory Alkalosis
- Respiratory alkalosis can be caused by pulmonary or extrapulmonary disorders, as stated in the study 2.
- Hyperventilation syndrome is a common etiology of respiratory alkalosis in the emergency department setting, and is a diagnosis by exclusion 2.
- Panic anxiety and dyspnea can also contribute to the development of respiratory alkalosis, as panic attacks can lead to hyperventilation 3, 4, 5.
- Other causes of respiratory alkalosis include:
- Hyperventilation due to various reasons such as anxiety, fear, or stress 6.
- Increased CO2 sensitivity, which can trigger panic attacks and hyperventilation in individuals with panic disorder 5.
- Subclinical abnormalities in respiration and other functions related to body homeostasis, which can contribute to the development of respiratory alkalosis in individuals with panic disorder 5.