Respiratory Rate
Overview
How to Measure
- Count the patient's breaths over 30 seconds to one minute while ostensibly measuring the pulse.
Normal Range
- 12 - 20 breaths per minute
Significance
- 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.
Tachypnoea
- 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
Bradypnoea
- 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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