Is hyperventilation characterized by deep or shallow breathing?

From the Guidelines

Hyperventilation is characterized by shallow, rapid breathing rather than deep breathing. This is based on the most recent evidence from the study published in the American Journal of Respiratory and Critical Care Medicine 1, which describes hyperventilation syndrome as having an abrupt onset of regular, rapid, shallow breathing disproportionate to the metabolic stress. The study highlights that subjects with psychogenic disorders, including hyperventilation syndrome, often exhibit abnormal breathing patterns at rest and during exercise, which can be almost diagnostic. Key characteristics of hyperventilation include:

• Abnormal increases in Ve, Ve/Vco, and respiratory frequency
• Respiratory alkalosis, as evidenced by decreased PetCO2 and Pa CO2
• Abrupt onset of regular, rapid, shallow breathing
• Chronic respiratory alkalosis with a downregulated Pa CO2 set point may also be observed at rest before exercise. It's essential to note that hyperventilation can lead to symptoms such as lightheadedness, dizziness, tingling in the extremities, chest pain, and shortness of breath, and treatment typically involves addressing the underlying cause and learning breathing techniques to slow and normalize the breathing pattern. Additionally, the BTS guideline for oxygen use in adults in healthcare and emergency settings 1 emphasizes the importance of excluding organic illness before making a diagnosis of hyperventilation and monitoring oxygen saturation in patients with a definite diagnosis of hyperventilation.

From the Research

Hyperventilation Characteristics

• Hyperventilation is defined as breathing in excess of the metabolic needs of the body, eliminating more carbon dioxide than is produced, and resulting in respiratory alkalosis and an elevated blood pH 2.
• The traditional definition of hyperventilation syndrome describes a syndrome characterized by a variety of somatic symptoms induced by physiologically inappropriate hyperventilation and usually reproduced by voluntary hyperventilation 2.

Breathing Patterns in Hyperventilation

• Hyperventilation can involve breathing too deeply and/or too rapidly, or erratic breathing interspersed with breath-holding or sighing 3.
• Breathing exercises, such as breathing control, diaphragmatic breathing, and yoga breathing, can be used to modify breathing patterns in patients with hyperventilation syndrome 3.
• A study found that breathing retraining, which involves acquiring an abdominal breathing pattern with slowing down of expiration, can modify the breathing pattern and reduce complaints in patients with hyperventilation syndrome 4.

Depth of Breathing in Hyperventilation

• A study examined the influence of duration and depth of hyperventilation on the development of symptoms and found that both depth and duration appeared to have an independent effect on the development of symptoms 5.
• The study suggested that a minimum duration of 3 minutes and an end-tidal PCO2 decreasing to at least 1.9 kPa or dropping well over 50% of baseline is advised to elicit symptoms in most people 5.
• However, the evidence does not clearly indicate whether hyperventilation is characterized by deep or shallow breathing, as it can involve a variety of breathing patterns 2, 5, 3, 4.