The relationship between Covid-19 and oxygen inhalation

Novel coronavirus pneumonia (Covid-19 for short), its main pathogenesis is the inflammatory secretions or exudates are abundant in the interstitium and alveoli of the lungs, blocking fresh air to enter alveolar and inside body carbon dioxide to undertake exchange. Thereby, bring about airbody anoxic, even much viscera function failure and death. At present, there is no specific anti-coronavirus drug, and more symptomatic and supportive therapy is adopted, in which oxygen inhalation is a very important symptomatic treatment measure throughout the treatment of Covid-19.

Sometimes patients with Covid-19 need oxygen therapy, but it mainly depends on the severity of the patient's condition. For mild and common COVID-19 patients, most patients have no obvious symptoms of asthma and chest tightness, and most patients have no obvious hypoxia.  At this time, there is no need oxygen therapy.

But for those patients with severe and critical Covid-19, there are obvious chest tightness, wheezing, and even breathing difficulties.Due to the severe inflammation of the lung tissue, which affects the ventilation function and diffusion function of the lungs, the patients are accompanied by varying degrees of hypoxemia or even respiratory failure. Such patients often need to be given high-concentration oxygen inhalation.Nasal oxygen cannula and oxygen mask can be used for oxygen inhalation. Some patients with severe respiratory failure also need to use ventilator to assist breathing to improve the body's hypoxia and maintain organ functions.  Therefore,oxygen therapy is one of the treatment options for patients with severe COVID-19.  

1. Why hypoxia?

The function of the lungs: to complete the gas exchange between oxygen and carbon dioxide.

The lungs are the first pass for fresh oxygen from outside to enter the human body. Oxygen enters the lungs with breathing, and exchanges with carbon dioxide through the capillary network of the alveolar wall. This exchange is a physical diffusion process under the action of oxygen or carbon dioxide partial pressure difference. It enters the heart from the pulmonary vein (pulmonary circulation) and then passes through the aorta (systemic circulation). Transports oxygen-rich blood to various organs and tissues of the body.A healthy adult has a stable breathing volume of 450-500ml at a time, and he breathes about 9 liters of air per minute, and breathes about 12,960 liters of air per day, which is equivalent to 16.8 kg. The purpose of inhaling so much air is to take in about 3.5 kg of oxygen. The quality of lung function directly determines the amount of gas exchange. The larger the lung capacity, the more oxygen can be inhaled, the stronger the alveolar diffusion function, and the healthier the person will be.

2. Monitoring of hypoxia

1. Blood oxygen saturation (SPO2)

It refers to the proportion of oxygen and hemoglobin. It is currently the most widely used and easiest data to obtain. It reflects the combined oxygen amount. The advantage is that it can be continuously monitored, but it is easily interfered by external factors. In theory, it can never be reached 100%. saturation.The blood oxygen saturation of a normal person is generally 95%-98%, generally more than 90% is good, less than 90% needs to be investigated for the cause of hypoxia, and oxygen inhalation is required, and less than 80% indicates that there is a serious deficiency. Oxygen requires blood gas analysis. The most commonly used finger oximeter in general medicine is the finger oximeter, which is easy to operate, non-invasive, accurate and portable.

2）The blood oxygen analysis

Arterial partial pressure of oxygen (PaO2) refers to the physical dissolved oxygen content in the blood. After the combined oxygen is in the body, it must first dissociate and become dissolved oxygen before it can be used by tissue cells. It can objectively reflect the hypoxia state of the body at that time, but it cannot be continuously observed and dynamically observed. Need to draw blood to complete. Normal value is 80-100mmHg, usually PaO2<60mmHg can be diagnosed as hypoxemia, PaO2<50mmHg indicates the existence of respiratory failure, PaO2<40mmHg indicates severe hypoxia, PaO2<30mmHg indicates life-threatening. PaO2 will decrease with age, and it can be considered as hypoxemia when it is below the lower limit of the same age.

3. Some suggestions to inhale oxygen

1. The purpose of oxygen inhalation includes the following aspects:

① Maintain normal blood oxygen saturation physiological indicators;

② Protect systemic organ functions;

③ Repair organ damage caused by hypoxia;

④ Reduce inflammatory exudation;

⑤ Enhance human immunity.

2.  How to do oxygen therapy?

Nebulizing oxygen inhalation: Germany reported that the application of nebulization has cured 4 patients with Covid-19 in a short period of time. If nebulizing oxygen therapy is used, it may bring more benefits to patients. The drug can be delivered directly to the respiratory tract and alveoli by aerosolization. Longfian oxygen concentrator is equipped with nebulization function, delivering oxygen with nebulization.

3. Patients with COVID-19 still have to adhere to do oxygen therapy after recovery. Most patients think that everything will be fine after recovery . In fact, the body organs of patients with COVID-19 have been damaged during treatment, especially after lung injury, which will indirectly affect the hypoxia of other organs. If can’t supplemented oxygen in time, the function of the organs will be reduced, or even inflammation will occur. Therefore, we should insist on oxygen therapy and recovery.