bradypneic

Bradypnea, or bradypneic as an adjective, is a clinical term describing an abnormally slow respiratory rate. In adults, a resting rate below 12 breaths per minute is generally considered bradypnea, whereas a normal adult rate is roughly 12–20 breaths per minute. Bradypnea can be a physiologic variation or a sign of underlying pathology or pharmacologic effects. It must be distinguished from apnea (cessation of breathing) and tachypnea (rapid breathing).

Causes are diverse and include physiologic states (sleep, athletic conditioning), drugs or toxins (opioids, sedatives, anesthetics, alcohol), neurologic disorders or injury affecting the brainstem, metabolic or endocrine disturbances (hypothyroidism, electrolyte abnormalities, hypothermia), and conditions that depress respiratory drive or impair chest wall mechanics. In clinical practice, bradypnea may reflect drug effect or a serious neurologic process and requires investigation.

Clinical evaluation focuses on confirming a slow rate and assessing oxygenation and ventilation. Signs may include shallow breathing and reduced chest movement, and severe cases can progress to hypoxemia or hypercapnia with altered mental status. Diagnostic workup may involve pulse oximetry, arterial blood gas analysis, ECG, toxin screening, thyroid studies, and imaging guided by suspected cause.

Management depends on cause and severity. When bradypnea is accompanied by hypoventilation or hypoxemia, airway protection and supplemental oxygen are indicated, and specific treatments are directed at the cause. Opioid- or sedative-induced bradypnea may respond to naloxone. In more severe cases, assisted ventilation may be required.

Bradypnea is a potentially dangerous sign when persistent or associated with inadequate respiration, and it warrants prompt medical evaluation. The term combines brady- meaning slow with pnea meaning breathing.