Standard use of long-term home oxygen therapy
Oxygen is an essential raw material for the human body to maintain life activities, adults need 250 ml of oxygen per minute in the resting state, and the body stores only 1 500 ml of oxygen, so acute hypoxia can be fatal for a few minutes. Chronic hypoxia is more common than acute hypoxia。
Chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, chronic heart failure and anemia all lead to hypoxia. Although the body can reduce the damage of hypoxia through compensatory reactions such as accelerating respiratory rate and increasing cardiac output, long-term chronic hypoxia can still lead to pulmonary hypertension, myocardial function decline, arrhythmia, memory decline and lethality. This can lead to pulmonary heart disease and heart failure.
Long-term hypoxia can also stimulate hematopoietic function, hemoglobin compensatory increase, produce high erythrocytopaemia, which increases the oxygen carrying capacity at the same time, but also lead to increased blood viscosity, hypercoagulability, resulting in increased cardiovascular and cerebrovascular diseases. Once the patient's condition worsens or the patient's oxygen demand increases (such as cold, tension, exercise, etc.), the damage caused by hypoxia can be further aggravated.
1、Oxygen inhalation is the most basic treatment for hypoxia.
Studies have shown that long-term home oxygen therapy can prolong the life expectancy of COPD patients with chronic hypoxemia, correct severe hypoxemia caused by disease progression, and delay disease progression.
Home oxygen therapy guidelines for adults were released in the United Kingdom in 2015 and home oxygen therapy guidelines for COPD patients in the United States in 2020. Based on existing evidence-based medical evidence, standardized recommendations for home oxygen therapy were put forward, including personalized oxygen therapy prescription and treatment education plan, safe oxygen supply system and use of portable oxygen inhalation equipment. The 2023 Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) also recommends long-term home oxygen therapy for COPD patients with PaO2≤55 mmHg (1 mmHg=0.133 kPa) or PaO2<60 mmHg at rest but with pulmonary heart disease or secondary polycythemia.
2、Definition of long-term home oxygen therapy
Long-term home oxygen therapy and pure oxygen inhalation are two different concepts. Oxygen inhalation is suitable for hypoxemia caused by various reasons or decreased blood oxygen caused by chest tightness, palpitation and other discomfort, oxygen inhalation time is not mandatory, based on whether the symptoms are relieved as the main reference. Long-term home oxygen therapy exists independently as a treatment for COPD and other diseases, and it has certain indications. Its purpose is to enable patients to achieve PaO2≥60 mmHg and/or SaO2 up to 90% at sea level and resting state, so as to maintain the function of vital organs and ensure the oxygen supply of surrounding tissues.
Patients with chronic hypoxemia who need long-term oxygen therapy need at least 15 hours of oxygen inhalation every day, long-term refers to patients who need several years or even lifelong oxygen inhalation, and most patients' conditions are irreversible. Oxygen can be supplied at home through oxygen cylinders or oxygen generators. Clinicians should comprehensively evaluate the patient's condition, airflow obstruction state, lifestyle and treatment preferences, and choose the appropriate oxygen therapy concentration, oxygen therapy time and oxygen delivery mode for patients, so as to prevent adverse reactions and ensure the safety, effectiveness and economy of long-term home oxygen therapy.
3, long-term home oxygen therapy precautions
Oxygen therapy and other therapeutic drugs, improper application can also produce adverse reactions, long-term inhalation of high concentration of oxygen will also produce oxygen free radicals, resulting in cell membrane damage, that is, oxygen poisoning. Therefore, before home oxygen therapy, the doctor should determine whether the patient meets the indications of long-term oxygen therapy, and determine the required oxygen flow through oxygen flow titration, and the patient's efficacy should be reevaluated at an interval of 2 to 3 months to judge whether oxygen therapy is effective and whether continued treatment is necessary.
click here to learn more about the home oxygen therapy
In the process of oxygen therapy, attention should be paid to the humidification and heating of oxygen to reduce the nasal mucosa discomfort. Nasal catheters and humidifying bottles should be strictly cleaned and disinfected and replaced regularly to avoid the growth of mold and bacteria to prevent cross-infection and secondary infection. Oxygen can help fuel, oxygen cylinders, oxygen generators should be placed in the shade, and away from fireworks and flammable products, smoking patients should pay particular attention to fire prevention. Oxygen cylinders should be handled to avoid tipping impact to prevent explosion.
Long-term home oxygen therapy may improve survival in COPD patients with severe hypoxia, but more clinical evidence is needed to evaluate its effectiveness and economic cost for use in other patients with chronic hypoxia.
