Breath Rate Measurement

Respiration is the exchange of oxygen and carbon dioxide. During internal respiration (tissue respiration), oxygen consumption and carbon dioxide production occur simultaneously. In external respiration (pulmonary respiration), carbon dioxide is exhaled and oxygen is taken in.

The respiratory rate depends on many factors such as age, body size and weight. In addition, the following factors are among influencing variables:

  • Gender
  • Posture (lying, sitting, standing)
  • Physical activity
  • Diseases
  • Psychological factors

One can determine the respiratory rate as follows:

  • Measurement of the change in chest circumference using a breathing belt during breathing.
  • Acquisition of the respiratory-synchronous amplitude modulation of the R-wave of the ECG (electrocardiogram (ECG; recording of the electrical activities of the heart muscle).
  • Determination of respiratory rate from respiratory blood pressure fluctuations: mean arterial pressure (MAD) drops to a minimum at the beginning of an inspiration (inhalation), and to the maximum during expiration (exhalation); the respiratory curve is obtained from the temporal progression

You can examine breathing by frequency, rhythm and quality:

Respiratory frequency (in adults)

  • Bradypnea: < 10/min
  • Norm: 12-18/min
  • Tachypnea: > 20/min

See also for respiratory rate under pneumonia (pneumonia)/sequelae/prognostic factors.

Average respiratory rate at:

  • Newborn: 40-45/min
  • Infant: 35-40/min
  • Toddler: 20-30/min
  • Child: 16-25/min

Age-dependent definition of tachypnea (According to WHO standards).

Patient age Respiratory rate (/min)
Birth approx. 60
< 2 months > 60
2-12 months > 50
1-4 years > 40
> 4 years > 30

Note: In children, tachypnea is often the first sign of respiratory insufficiency (disturbance of external respiration resulting in inadequate ventilation of the alveoli).

Respiratory rhythm

  • Regular
  • Irregular

Breath type

Physiological

  • Abdominal breathing (abdominal breathing) or diaphragmatic breathing (diaphragmatic breathing) – quiet, regular breathing without pauses.
  • Breathing time ratio – inspiration (inhalation): expiration (exhalation) = 1: 2.

Pathological

  • Biot respiration – breathing pattern with intermittent (lat. intermittere = interrupt/suspend) pauses; occurs in cerebral disease, intracranial pressure increase, intracranial hemorrhage (bleeding within the skull; parenchymatous, subarachnoid, sub- and epidural, and supra- and infratentorial hemorrhage)/intracerebral hemorrhage (ICB; brain hemorrhage), brain tumors, and meningoencephalitis (combined inflammation of the brain (encephalitis) and meninges (meningitis)) or Meningitis (meningitis) on.
  • Cheyne-Stoke breathing (synonym: periodic apnea) – in disorders of the respiratory center occurring form of respiratory disorder, in which there are periodic sequences of deep breaths alternating with flattening breaths; occurs in: insufficient cerebral blood supply, ie ischemia in arteriosclerosis, up to apoplexy (stroke), furthermore in intoxications (eg with carbon monoxide (CO))
  • Kussmaul breathing – breathing disorder with very deep breaths, which occurs in metabolic acidosis.
  • Breathing movements not lateral in pneumonia (pneumonia), pneumothorax (gas chest).
  • Use of auxiliary respiratory muscles – in dyspnea (shortness of breath).
  • Altered respiratory time ratio – in obstructive lung disease (in these severe pulmonary. Gas exchange disorders, the normal inspiratory duration is often not enough).