Hypocapnia
Under hypocapnia is understood to mean a decreased Kohlenstoffdioxidpartialdruck (pCO 2 ) in arterial blood (paCO 2 under 32-35 mmHg)
This hypocapnia can occur, for example, when breathing too fast and / or deeply, so-called hyperventilation , or with respiratory compensation for metabolic acidosis (exhalation of acid valences).
An increased partial pressure of carbon dioxide is known as hypercapnia .
Symptoms and Risks
Hypocapnia causes cerebral vasoconstriction ( vasoconstriction of the brain ), which in turn can lead to cerebral hypoxia , which can lead to drowsiness and other symptoms.
Insofar as hypocapnia does not compensate for acidosis , it causes respiratory alkalosis . The alkalosis leads to decreased plasma calcium levels and thus to increased excitability of nerves and muscles . This explains the other symptoms of hypocapnia: resting muscle cramps , especially in the extremities, and ants tingling.
The CO 2 level in the blood is normally used to drive breathing. Untrained divers in the swimming pool hyperventilate before diving in order to breathe out a lot of CO 2 and thus stay under water longer. This should only take place under controlled conditions, as there is a risk of loss of consciousness and drowning ( swimming pool blackout ).
Individual evidence
- ↑ Lisa MK Chin et al .: Hyperventilation-induced hypocapnic alkalosis slows the adaptation of pulmonary O 2 uptake during the transition to moderate-intensity exercise In: J Physiol . 2007 Aug 15; 583 (Pt 1): 351-364, PMC 2277242 (free full text), PMID 17584832 .
