bradypnea

Bradypnea is an abnormally slow rate of breathing. In adults, it is typically defined as fewer than 12 breaths per minute, though normal rates can vary with age, activity, and circadian factors. Bradypnea may occur with shallow breathing and reduced ventilation and can indicate respiratory or neurologic dysfunction, especially when accompanied by low oxygen levels or high carbon dioxide in the blood.

Causes of bradypnea are diverse. Central nervous system depression from drugs such as opioids, sedatives, alcohol, or anesthesia is a common cause. Neurologic injury or disease, including traumatic brain injury, stroke, or increased intracranial pressure, can slow respiration. Endocrine or metabolic conditions such as hypothyroidism or hypothermia, severe illness, and certain sleep states in otherwise healthy individuals can also produce slower breathing. Less frequently, bradypnea may reflect coordinated protective responses in well-trained athletes or during deep sleep.

Diagnosis and assessment involve careful measurement of respiratory rate and effort, along with monitoring of oxygen saturation and, if indicated, arterial blood gases to evaluate gas exchange. Clinicians differentiate bradypnea from other patterns such as apnea and assess for signs of respiratory failure, altered mental status, or hemodynamic instability. Additional investigations may include imaging or neurologic evaluation to identify underlying causes.

Management depends on severity and etiology. Stable patients with mild bradypnea may be monitored with observation and vital sign checks. If there is hypoxemia, hypercapnia, or altered consciousness, airway support and supplemental oxygen are indicated, and treatment targets the underlying cause. Suspected opioid overdose requires prompt administration of antagonists such as naloxone, with careful monitoring due to possible re-sedation. Overall, bradypnea is a sign rather than a disease, and prognosis hinges on the underlying condition.