Low Respiratory Rate, Bradypnoea (< 10 bpm)

MANUAL OF CLINICAL DIAGNOSIS

Bradypnoea is defined as an abnormally low respiratory rate, generally less than 10 breaths per minute (bpm). This symptom may indicate an impairment in the mechanisms that control breathing and can be potentially dangerous, as it may lead to hypoventilation and, consequently, to hypoxia and the accumulation of carbon dioxide (hypercapnia). Identifying and treating the underlying cause are essential to prevent serious complications.

Pathology	Clinical Symptoms and Signs	Suspected Diagnosis	Confirmatory Diagnosis
CO2 Narcosis	Bradypnoea, confusion, drowsiness, headache, flushed face, hypercapnia	Medical history, arterial blood gas analysis	Arterial blood gas analysis, elevated CO2 levels
Medication-Induced	Bradypnoea, drowsiness, decreased level of consciousness, miosis (opioids)	Medication history, physical examination	Arterial blood gas analysis, blood medication levels
Increased Intracranial Pressure	Bradypnoea, headache, nausea, vomiting, papilloedema, altered mental state	Medical history, physical examination, CT scan	Cranial CT scan, MRI
Traumatic Brain Injury	Bradypnoea, loss of consciousness, amnesia, focal neurological signs	History of trauma, physical examination	Cranial CT scan, MRI
Cervical Spinal Cord Injury	Bradypnoea, weakness or paralysis, loss of reflexes, neurogenic shock	History of trauma, neurological examination	Cervical spine MRI, electromyography
Acute Neuromuscular Disease	Bradypnoea, generalised muscle weakness, difficulty swallowing, dysarthria	Medical history, neurological examination	Electromyography, nerve conduction studies, antibody testing
Severe Hypothermia	Bradypnoea, bradycardia, confusion, drowsiness, cold and pale skin	History of cold exposure, physical examination	Thermometry, arterial blood gas analysis, ECG