Hyperventilation

In a hyperventilation (from Greek ὑπέρ " about" and Latin ventilare " fan " ), is an on demand Increased lung ventilation. It is accompanied by a decrease in the partial pressure of carbon dioxide (CO2 ) and an increase in pH (respiratory alkalosis) in the blood. A hyperventilation as a disturbance of respiratory regulation occur from psychological or physical reasons ( hyperventilation syndrome, primary hyperventilation), in response to an undersupply show occur ( for diseases of the cardiovascular system, secondary hyperventilation) or even with controlled ventilation.

In addition to the acute hyperventilation syndrome, which is characterized by paroxysmal accelerated and deepened breathing with the typical tetanic symptoms, chronic hyperventilation syndrome, a distinction that is counted to the group of somatization disorder often associated with non-unique symptoms. The anxiety -related, acute hyperventilation can sometimes cover an underlying problem (eg, pneumothorax).

The adjusted at an increased respiratory demand breathing volume during work ( physical stress ) is not hyperventilation. The opposite (too much carbon dioxide in the blood ) is called hypoventilation. The phenomenon of an too rapid breathing, without regard to the concentration of carbon dioxide in the blood is known as tachypnea.

Causes

A hyperventilation is a disorder of respiratory control, which is usually due to psychological illness. Strong emotions such as fear, panic or excitement, but also pain or depression can lead to accelerated breathing.

In addition, may be the cause hyperventilation by physical illness such as encephalitis, brain tumors, traumatic brain injury, stroke, electrolyte disturbances, poisoning and infectious diseases that must be considered diagnostic.

The differential diagnosis of physical disorders must be ruled out, cause a compensatory increase in respiration, such as heart failure and lung disorders.

A special case of ( voluntary, but not intended ) hyperventilation may occur in the circular breathing as they wind instruments players, especially when Didgeridoo use. Some respiratory therapy and respiratory teachings deliberate use Hyper ventilation, so Kapalabhati, an exercise of the Indian teaching pranayama breathing or holotropic breathing. Free divers (diving without aids ) reject the hyperventilation as an easy way to extend the dive time without device support because of the danger they largely depend.

Respiratory regulation in the body

The respiratory minute volume of people is primarily regulated by the concentration of CO2 in the arterial blood. The measurement of CO2 concentration is the one preferred by the brain stem central chemoreceptors and on the other by peripheral chemoreceptors, the aortica are located in the carotid body and in the glomera. Increases the CO2 content in the blood, the breathing time volume increases ( mediation by the respiratory center ). A secondary respiratory control ( under normal conditions significantly less influence) take oxygen ( can only be measured in peripheral chemoreceptors ) and pH receptors that increase the breathing time volume is too low oxygen supply or to low pH.

Pathophysiology

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

So, by recessing or rapid breathing, there is a decrease in the concentration of CO2 in the blood. If less CO2 is present, carbon dioxide reacts off to restore the balance. This also leads to a decrease in the concentration of H3O and thus to a rise in the pH value of blood (respiratory alkalosis).

To understand the consequences of hyperventilation a basic knowledge about the state of the cerebral vessels as a function of the concentration of CO2 in the blood is required: a high CO2 concentration is generally at a low O2 concentration along. In this case, expanding the blood vessels of the brain, in order to ensure an adequate supply of the nerve cells with oxygen. When hyperventilation now enters the reverse: The abnormally low CO2 concentration leads to a constriction of the cerebral vessels. This leads to the paradoxical situation that an increased respiratory activity despite maximal oxygen saturation leads to an insufficient supply of the brain with oxygen.

Due to the pH shift, it also leads to distortions of electrolyte balance, especially to a relative (relative, because it is not the concentration of calcium but decreases the fraction of freely dissolved ionized calcium to total calcium in the blood) hypocalcemia by the increased binding to negatively charged plasma proteins. This can be explained by the fact that plasma proteins to dispense with elevated blood pH values ​​protons to the blood and thus a negatively charged binding site is free. Calcium has a membrane-stabilizing effect. Then the relative concentration decreases, this leads to hyper-excitability of the nervous system and muscles, and thus the typical neuromuscular symptoms (eg, convulsions, " obstetrician ").

Symptoms

For those concerned there is a rapid breathing rate ( tachypnea ), they complain about the same time strong shortness of breath, the pressure of having to take a deep breath and tightness across the chest. Yawn, sigh and a cough may also occur. Typical are the neuromuscular symptoms. Characteristically, enter numbness and paresthesia ( paraesthesia, as " pins and needles " perceived ), accompanied by spasms of the hands ( " obstetrician " ) and lips ( " carp mouth" ), trembling, muscle aches, and sometimes paralysis of the extremities. Accompanying are often headache, dizziness, blurred vision and dizziness, in part, until syncope.

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

With chronic disease digestive problems may continue ( belching, bloating, dysphagia ) may occur, which often match the symptoms of irritable bowel syndrome. Fatigue, drowsiness, difficulty concentrating, forgetfulness, irritability, changes in the weather as well as phobic or panic states are also possible symptoms of chronic course.

Treatment

The focus of the treatment of acute hyperventilation is a calming of the person concerned, with the instructions to deliberately slow and decreased breathing. If this is not possible because of fear and excitement, a rebreathing is displayed ( in a plastic or paper bag or a hyperventilation mask or oxygen mask with oxygen flow off ). Through the repeated inhaling and exhaling of your own kohlenstoffdioxidhaltigen breath CO2 concentration increases in the patient's blood again, and the previously constricted cerebral vessels dilate again. Sometimes is a pharmaceutical sedation, for example, a benzodiazepine, is necessary. Today is no longer practiced a balance of acid -base balance, or the intravenous administration of calcium.

Chronic hyperventilation syndrome is treated by psychotherapy, as well as with physical and respiratory therapy and relaxation techniques. About 60% of patients develop including an improvement.

As part of body psychotherapeutic methods such as Bioenergetic Analysis (Alexander Lowen ), rebirthing and holotropic breathing is hyperventilation consciously used for therapeutic purposes.