Respiratory arrest, or apnea, refers to a complete interruption of external breathing. Respiratory arrest can have very many different causes, ranging from voluntary interruption to disease to certain traumas or poisoning with neurotoxins. After only a few minutes, respiratory arrest becomes critical because of the onset of hypoxia.
What is respiratory failure?
A complete cessation of external breathing is called respiratory arrest or apnea. Respiratory arrest can be voluntary by simply holding one’s breath or it can be caused by external factors. In involuntary apnea, either the respiratory reflex is momentarily or permanently impaired or the respiratory muscles are paralyzed. In the vast majority of cases, respiratory arrest is triggered by traumatic brain injury (SHT). Breathing can also be interrupted by a mechanical blockage of the airways, such as in sleep apnea. Gas exchange in the capillaries of the alveoli, like gas exchange in the capillaries within the tissue, is initially maintained for a short time. Only after the oxygen of the remaining air volume in the lungs has been used up does the exchange of carbon dioxide for molecular oxygen and vice versa come to a standstill. Not only does an oxygen deficiency (hypoxia) then occur, but also a dangerous overconcentration of carbon dioxide, which causes hyperacidity.
Causes
Respiratory failure can have a wide variety of causes that require different measures to correct the problem. By far the most common culprits are obstructive sleep apnea syndrome and a condition called traumatic brain injury (SHT). In obstructive sleep apnea, a blockage of the upper airway occurs during sleep. The smooth ring muscles around the upper airways relax to such an extent that the upper part of the trachea virtually mutates into a tube with tensionless walls. The slight negative pressure created during inhalation causes the walls to “collapse,” resulting in the blockage. SHT, which can occur due to an accident, is usually accompanied by unconsciousness and failure of many brain functions. In more severe cases, the respiratory center may also be so disrupted that the respiratory reflex fails and respiratory arrest develops. Paralysis of the respiratory muscles due to disease or to poisoning with neurotoxins can also lead to respiratory arrest. A blow to the solar plexus nerve plexus by accident or other force, can trigger a reflex that causes the respiratory muscles to spasm, resulting in (usually) temporary respiratory arrest.
Symptoms, complaints, and signs
Outward signs of respiratory arrest include loss of consciousness, the absence of any airflow through the nose or mouth, dilated pupils, and a slight blue discoloration of the skin (cyanosis) that becomes apparent after a few minutes. Prolonged respiratory arrest initially leads to a lack of oxygen (hypoxia), so the internal organs and also the brain are irreversibly damaged, so that the affected person may die of organ failure. Sometimes, various symptoms such as headache, nausea, but also sometimes euphoria and strong overconfidence are possible. These are symptoms typically observed in altitude sickness. Affected persons can die in the worst case if the respiratory arrest is not treated in time. Even if treatment has been given, in some cases the brain may be so severely damaged that the affected person suffers from reduced intelligence or other disabilities and psychological symptoms as a result of the respiratory arrest. The affected person’s quality of life is significantly reduced as a result. If the respiratory arrest lasts for about ten minutes, the patient will die in most cases. Death can be prevented by mouth-to-mouth resuscitation until the arrival of the emergency physician.
Diagnosis and course
This causes a rapid increase in the concentration of carbon dioxide in the blood, which is thought to trigger the maximum stimulus in the respiratory center to elicit a spontaneous breath. The lack of oxygen, if respiratory arrest continues, is accompanied by a dangerous increase in the concentration of carbon dioxide in the blood, which normally triggers a strong breathing reflex. Remarkably, if the carbon dioxide concentration rises even further, the breathing reflex weakens again and stops completely.In the further course, symptoms of poisoning and irreversible damage to the nerve cells in the brain now set in. If no immediate countermeasures are taken, death by asphyxiation is inevitable. If this fails to occur, there is a total failure of the respiratory center, an important criterion for determining brain death. For example, one of the ultimate tests for suspected brain death is to ventilate the person affected by respiratory failure with pure oxygen while reducing ventilation.
Complications
It is imperative that respiratory arrest be treated directly by a physician or in the hospital. If respiratory arrest is not treated, it will lead to death in most cases. Death occurs when the brain and other organs have been deprived of oxygen for too long, causing severe damage. If a patient has suffered from respiratory arrest and was subsequently resuscitated, the degree of injury will depend greatly on how long the organs were deprived of oxygen. In the case of a short respiratory arrest, it is assumed that most organs are not damaged. After that, the brain functions without much difficulty. After the respiratory arrest itself, the patient complains of a severe headache and nausea. If the respiratory arrest lasts longer, the brain is damaged. After that, certain parts of the brain can no longer function properly, which can lead to thinking disorders. It is not uncommon for the brain to be unable to control certain parts of the body properly. If the respiratory arrest lasts even longer, this usually leads to death and also cardiac arrest. Resuscitation must be performed immediately to avoid damage to organs.
When should you go to the doctor?
When a person’s breathing stops, his or her life is in serious danger. Therefore, every respiratory arrest is a reason to call the emergency doctor and to have the cause clarified after the necessary rescue measures. At best, in the event of a respiratory arrest, one person provides first aid while another contacts the emergency physician, because if the patient is not helped immediately, he may die within a few minutes due to the lack of oxygen. Even if he survives the respiratory arrest or resumes breathing on his own, after a longer period of time it is questionable how much damage has been done to the brain. The affected person could wake up severely disabled or not wake up at all, even if breathing resumes. Many respiratory arrests do not even happen in such dramatic situations, but are of short duration and are sometimes not even consciously noticed – for example in cases of sleep apnea. Nevertheless, they are just as dangerous as in any other case. In the case of sleep apnea, however, the emergency doctor does not have to be called immediately, as those affected begin to breathe again all by themselves. However, a medical check-up must still be carried out in order to avoid really dangerous situations and to stop the nocturnal breathing stops. In infants and young children, sudden respiratory arrest is a trigger for sudden infant death syndrome, which is why children at risk, such as premature infants, should be monitored by a doctor as a precaution.
Treatment and therapy
The multiple causes of respiratory arrest necessitate immediate action to correct the respiratory arrest or, if that is not possible, to prevent it. Urgency is required in treating a respiratory arrest that poses a life-threatening situation, as serious damage to health can occur within minutes. If the respiratory arrest is caused by mechanical obstruction of the upper airway by foreign bodies, removal of the foreign bodies will bring immediate relief. If removal is not possible, immediate tracheotomy (coniotomy) below the larynx may be life-saving. The same measure may be required for allergic reactions to an insect bite in the throat if swelling of the tissue firmly shuts the trachea. In the many cases where respiratory arrest is coupled with cardiovascular failure, resuscitative measures are required. These measures range from simple chest compressions coupled with mouth-to-mouth resuscitation to the use of a defibrillator and injections or infusions. Cardiac massage, performed at a rate of about 100 to 120 per minute by rhythmic pressure on the sternum, should be followed by 2 attempts at ventilation after every 30 or so pressures.In the case of respiratory arrest induced by neurotoxins, narcotics or intoxicants, in addition to resuscitative measures, antidotes are available in certain cases such as snakebite or mushroom poisoning, which at best neutralize the toxins. In the presence of certain neurologic diseases that cause permanent impairment of natural respiration, permanent active ventilation by appropriate equipment may be necessary.
Outlook and prognosis
The outlook and prognosis for respiratory failure depend on the exact cause of the respiratory arrest and how quickly breathing resumes. On the other hand, if breathing does not resume at all, death by asphyxiation is the result after a few minutes. A subsequent attempt at resuscitation can still be successful after several minutes, but in almost all cases will result in severe and irreversible brain damage. This occurs after as little as three minutes without an oxygen supply and can affect all areas of the brain. Lack of oxygen due to suspended breathing leads to hypoxemia within a very short time and subsequently to organ and brain damage. Occasional interruptions of breathing for a few seconds are normal in many people (in the context of sleep apnea, for example) and have no acute damaging effect. However, long-term damage due to recurrent brief oxygen deficiency is possible. Apnea due to mechanical causes (strangulation, swallowing, etc.) can usually be stopped by removing the trigger. Organic causes – especially nerve and muscle damage – if they cause breathing to stop, usually mean that breathing can no longer be induced by the affected person. Until the causative disease is cured, he or she is initially dependent on artificial respiration. In general, the sooner a person who suffers a respiratory arrest – regardless of the cause – is ventilated, the better the prognosis with regard to subsequent damage. Respiratory arrests that are not due to complete organic failure can therefore be bridged until the cause is found.
Prevention
Because of the variety of possible causative agents of respiratory arrest, preventive measures that might prevent respiratory arrest are almost impossible. General preventive measures include keeping healthy and not abusing alcohol or other drugs.
Aftercare
Whether follow-up care is needed as a result of respiratory failure depends primarily on the cause. Neurologic disease and damage to the respiratory muscles can always cause the familiar symptoms to recur. In these cases, a new presentation to the doctor is indispensable. The situation is different, however, when acute causes cause the respiratory arrest. An electrical accident or strangulation cannot be expected to recur. Therefore, a recurrence can be ruled out, which is why follow-up examinations are not necessary after a complete recovery. Sometimes the symptoms of respiratory arrest cannot be treated at all. This is especially the case when breathing stops for a long period of time. The brain is damaged, as described above. This leads to the fact that certain organs can no longer be controlled properly. Renewed complications such as respiratory arrest can occur again and again. Patients must therefore see a doctor regularly for follow-up care. In order to live symptom-free in everyday life, patients can receive help to reduce factors that promote the disease. As a general rule, patients should refrain from nicotine, alcohol and drugs. Follow-up care may also include training family members how to resuscitate a patient in the event of respiratory arrest.
Here’s what you can do yourself
In the event of a respiratory arrest, first aid measures must be taken immediately. If necessary, the affected person must be taken out of the danger zone before further treatment takes place. Ideally, the victim should be placed in the recovery position and immobilized. If necessary, resuscitation measures such as mouth-to-mouth resuscitation must be performed directly on site. In addition, the emergency physician should be alerted immediately. Using the W-questions, all relevant information must be given to the rescue service so that immediate treatment can be given. Further self-measures depend on the cause of the respiratory arrest.If a foreign body is the cause, it must be carefully removed from the mouth or throat. The head should be turned to the side so that vomit can drain away. If pollutants or toxins are suspected as the cause, respiratory donation should not be performed. In this case, cardiopulmonary resuscitation is more useful. After the initial respiratory arrest has been treated, the most important thing is rest and bed rest. The patient should recover for a few days and then slowly return to everyday life. Talking to a therapist can help work through the respiratory arrest to prevent psychological problems from developing.
