Vital Signs

Respiratory Rate



    • The respiratory rate is an important vital sign that is an early marker of deterioration.
  • The diaphragm has both somatic and autonomic innervation, and thus the respiratory rate can be altered both voluntarily and and involuntarily in response to physiologic or pathologic stimuli.
      • Normal Range

      • 12 - 20 breaths per minute
    • How to Measure

    • Count the patient's breaths over 30 seconds to one minute while ostensibly measuring the pulse.


  • Respiratory rate greater then 20 breathes per minute.
    • Causes of Tachypnoea

    • Physiologic - during exercise or at high altitude
    • Anxiety
    • Metabolic acidosis - abdominal pathology, sepsis
    • Pulmonary embolism
    • Pneumonia
    • Asthma
    • Respiratory failure


  • Respiratory rate less than 12 breaths per minute.
    • Causes of Bradypnoea

    • Respiratory suppression
    • Drugs - opioids
    • Respiratory failure
    • Hypothyroidism
    • Raised intracranial pressure
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