Hypercapnia

Classification according to ICD-10
T59	Toxic effect of other gases, vapors or other smoke
T59.7	carbon dioxide
J96.0	Acute respiratory failure, not elsewhere classified
J96.1	Chronic respiratory failure, not elsewhere classified
J96.2	Respiratory failure, not elsewhere classified
J96.9	Respiratory failure, unspecified
ICD-10 online (WHO version 2019)

Under hypercapnia (from Greek ὑπέρ "about" and καπνός "haze, smoke, gas") is meant an increased carbon dioxide content in the blood.

This can be defined via the partial pressure ; the normal value (carbon dioxide partial pressure in human blood) is 40 mmHg for arterial blood (normal paCO ₂ : 32–45 mmHg or 4.27–6.40 kPa). From a value of about 45 mmHg one speaks of hypercapnia. There are people who have permanent hypercapnia due to a chronic inferior function of their breathing and are adapted to it. From a value of around 60 mmHg, increasing CO ₂ anesthesia occurs .

The level of this pressure is determined by two factors:

the production of carbon dioxide
the exhalation of carbon dioxide ( alveolar ventilation )

An increased production of carbon dioxide can usually be "exhaled", unless there are pathological circumstances (e.g. decreased compliance ). The increased carbon dioxide partial pressure mainly leads to respiratory acidosis .

The antonym to hypercapnia, i.e. too low a carbon dioxide content in the blood, is known as hypocapnia .

causes

Hypercapnia is usually caused by a pulmonary ventilation disorder (formerly known as global respiratory failure ), which arises from alveolar hypoventilation , pulmonary diffusion disorder or pulmonary distribution disorder . For example, hypercapnic respiratory failure can occur with a sudden worsening of chronic obstructive pulmonary disease (COPD) . Hypercapnia also arises from metabolic alkalosis or from inhalation of air with a high concentration of carbon dioxide (from 8 to 10 percent by volume, there is carbon dioxide poisoning ).

Symptoms

At first there is reddening of the skin , muscle twitching , extrasystoles . In the advanced stage, panic , seizures , impaired consciousness and finally coma ( CO ₂ anesthesia ) occur.

therapy

To treat hypercapnic respiratory failure, the patient can be mechanically ventilated to support the work of breathing, for example with pressure-supported, non-invasive ventilation with a high gas flow (possibly over 60 liters per minute) of the oxygen-air mixture.

literature

Pschyrembel. Clinical Dictionary . 261st edition. Walter de Gruyter, Berlin / New York 2007

Individual evidence

↑ Harald Genzwürker, Jochen Hinkebein: Case book anesthesia, intensive care medicine and emergency medicine. Georg Thieme, Stuttgart / New York 2005, ISBN 3-13-139311-4 , p. 301.
↑ Hilmar Burchardi: Etiology and pathophysiology of acute respiratory failure (ARI). In: J. Kilian, H. Benzer, FW Ahnefeld (ed.): Basic principles of ventilation. Springer, Berlin a. a. 1991, ISBN 3-540-53078-9 , 2nd, unchanged edition, ibid. 1994, ISBN 3-540-57904-4 , pp. 47-91; here: p. 53.
^ Rolf Dembinski: Non-invasive forms of ventilation. In: Anesthesia & Intensive Care Medicine. Volume 60, June 2019, pp. 308-315.

[1] Harald Genzwürker, Jochen Hinkebein: Case book anesthesia, intensive care medicine and emergency medicine. Georg Thieme, Stuttgart / New York 2005, ISBN 3-13-139311-4 , p. 301.

[2] Hilmar Burchardi: Etiology and pathophysiology of acute respiratory failure (ARI). In: J. Kilian, H. Benzer, FW Ahnefeld (ed.): Basic principles of ventilation. Springer, Berlin a. a. 1991, ISBN 3-540-53078-9 , 2nd, unchanged edition, ibid. 1994, ISBN 3-540-57904-4 , pp. 47-91; here: p. 53.

[3] Rolf Dembinski: Non-invasive forms of ventilation. In: Anesthesia & Intensive Care Medicine. Volume 60, June 2019, pp. 308-315.