# Hyperventilation

 The articles respiratory alkalosis and hyperventilation overlap thematically. Help me to better differentiate or merge the articles (→  instructions ) . To do this, take part in the relevant redundancy discussion . Please remove this module only after the redundancy has been completely processed and do not forget to include the relevant entry on the redundancy discussion page{{ Done | 1 = ~~~~}}to mark. Nescimus ( discussion ) 7:14 pm , Feb. 22, 2017 (CET)
Classification according to ICD-10
R06.- Breathing disorders
R06.4 Hyperventilation
F45.33 Somatoform autonomic dysfunction: respiratory system
ICD-10 online (WHO version 2019)

At a hyperventilation (from ancient Greek ὑπέρ hyper , German , over ' and Latin ventilare , fanning') is, to provide increased ventilation of the lungs . It goes with a decrease in carbon dioxide - partial pressure of (CO 2 ) and a pH -increase ( respiratory alkalosis ) associated in the blood. Hyperventilation can occur as a disturbance of the respiratory regulation for psychological or physical reasons ( hyperventilation syndrome , primary hyperventilation ), as a reaction to an undersupply (in diseases of the cardiovascular system , secondary hyperventilation ) or it can also occur with controlled ventilation .

In addition to the acute hyperventilation syndrome, which is characterized by accelerated and deepened breathing that occurs in attacks with the typical tetanic symptoms , a distinction is made between the chronic hyperventilation syndrome, which belongs to the group of somatization disorders and is often associated with unclear symptoms. The fear-related, acute hyperventilation can sometimes mask an underlying problem ( e.g. pneumothorax ).

The adjusted respiratory volume when working (physical stress) is not hyperventilation. The opposite (too much carbon dioxide in the blood) is called hypoventilation . The phenomenon of breathing too quickly, regardless of the concentration of carbon dioxide in the blood, is known as tachypnea .

## causes

Hyperventilation is a disorder of breathing regulation, which is mostly psychological. Strong affects such as fear , panic or excitement , but also pain or depression can lead to accelerated breathing.

In addition, hyperventilation can also be caused by physical illnesses such as inflammation of the brain , brain tumors , traumatic brain injury , stroke , electrolyte disorders, poisoning and infectious diseases, which must be taken into account diagnostically.

In the differential diagnosis , physical disorders that cause a compensatory increase in breathing, such as heart failure and diseases of the lungs, must be excluded .

A special case of (voluntary but unintentional) hyperventilation can occur with circular breathing , as used by wind instrument players , especially with the didgeridoo . Some breathing therapies and breathing teachings use intentional hyperventilation, such as Kapalabhati , an exercise in the Indian breathing teachings Pranayama , or holotropic breathing . Freedivers (divers without aids) largely reject hyperventilation as a simple way of extending the diving time without equipment support because of its dangerousness.

## Breath regulation in the body

The human respiratory minute volume is primarily regulated by the CO 2 concentration in the arterial blood. The CO 2 concentration is measured on the one hand by central chemoreceptors located in the brain stem and on the other hand by peripheral chemoreceptors located in the carotid body and in the aortic glomera . If the CO 2 content in the blood increases, the respiratory time increases (mediated by the respiratory center ). A secondary respiratory control (significantly less influence under normal conditions) is carried out by oxygen (can only be measured in peripheral chemoreceptors) and pH receptors, which increase the respiratory time volume if the oxygen supply or pH value is too low.

## Pathophysiology

The increased ventilation hardly leads to an increased uptake of oxygen in the body, since the saturation of the blood with oxygen is about 97% even with normal breathing. However, there is increased exhalation of the carbon dioxide produced in the body. Carbon dioxide is bound as carbonic acid in the blood :

${\ displaystyle \ mathrm {CO_ {2} +2 \ H_ {2} O \ leftrightharpoons H_ {2} CO_ {3} + H_ {2} O \ leftrightharpoons HCO_ {3} ^ {-} + H_ {3} O ^ {+}}}$

Deeper or accelerated breathing therefore leads to a decrease in the CO 2 concentration in the blood. When there is less CO 2 , carbonic acid also reacts to restore the balance. This also leads to a decrease in the H 3 O + concentration and thus to an increase in the pH value of the blood ( respiratory alkalosis ).

Understanding the consequences of hyperventilation requires basic knowledge of the condition of the cerebral vessels as a function of the CO 2 concentration in the blood: A high CO 2 concentration is generally associated with a low O 2 concentration. In this case, the vessels in the brain expand to ensure that the nerve cells are adequately supplied with oxygen. With hyperventilation, the opposite occurs: the abnormally low CO 2 concentration leads to a constriction of the brain vessels. This leads to the paradoxical situation that increased breathing activity despite maximum oxygen saturation leads to an insufficient supply of the brain with oxygen.

The pH shift also leads to disturbances of the electrolyte balance, in particular to relative hypocalcemia (relative, because it is not the concentration of calcium that decreases, but the proportion of freely dissolved ionized calcium in the total calcium in the blood) due to the increased binding to negative charged plasma proteins. This can be explained by the fact that plasma proteins release more protons into the blood when the blood pH values ​​are increased, thus freeing a negatively charged binding site. Calcium has a membrane stabilizing effect. If the relative concentration now falls, this leads to overexcitability of the nervous system and muscles and thus to the typical neuromuscular symptoms (e.g. cramps, "paw position").

## Symptoms

Those affected have a high breathing rate ( tachypnea ), they complain of severe shortness of breath , the compulsion to breathe deeply, and a feeling of tightness over the chest. Yawning , sighing and a dry cough can also occur. The neuromuscular symptoms are typical. Characteristically, numbness and abnormal sensations ( paresthesia , perceived as " pins and needles ") occur, accompanied by cramps in the hands ("paw position") and lips ("carp mouth"), tremors, muscle pain and occasionally paralysis of the extremities. This is often accompanied by headache, dizziness, visual disturbances and drowsiness, sometimes up to syncope .

Also cardiac symptoms may occur and as chest pain (on the chest), palpitations and heart palpitations ( palpitations express).

With chronic symptoms, digestive problems (belching, flatulence, swallowing disorders) can occur, which often correspond to the symptoms of irritable bowel syndrome . Fatigue , drowsiness, concentration disorders, forgetfulness, irritability, sensitivity to the weather and phobic or panic states are also possible symptoms of the chronic course.

## treatment

In the treatment of acute hyperventilation, the focus is on calming the person affected with instructions to consciously slow and reduce breathing. If this is not possible due to fear and excitement, rebreathing (into a plastic or paper bag or a hyperventilation mask or oxygen mask with the oxygen flow switched off) is indicated. By inhaling and exhaling the patient's own carbon dioxide-containing air several times, the CO 2 concentration in the patient's blood rises again, and the previously constricted brain vessels expand again. At times, pharmaceutical sedation , e.g. B. with a benzodiazepine , necessary. Balancing the acid-base balance or intravenous administration of calcium is no longer practiced today .

Chronic hyperventilation syndrome is treated with psychotherapeutic treatment as well as physiotherapy and respiratory therapy and relaxation procedures. In about 60% of the patients there is an improvement.

In the context of body psychotherapeutic procedures such as bioenergetic analysis ( Alexander Lowen ), rebirthing and holotropic breathing , hyperventilation is consciously used for therapeutic purposes.

## Individual evidence

1. ^ Werner Stangl: Hyperventilation. In: Online Lexicon for Psychology and Education. Retrieved October 31, 2018 .