What are the causes of respiratory muscle fatigue?

summary

Respiratory muscle fatigue or respiratory muscle dysfunction is very common in patients with chronic lung disease and ICU. For a long time, respiratory muscle fatigue or failure has not been paid attention to. Timely detection and treatment of respiratory muscle fatigue can correct abnormal respiratory mechanics, reduce respiratory work, improve oxygenation and shorten the time of mechanical ventilation. Therefore, in recent years, the evaluation of respiratory muscle function in critically ill patients has become one of the important contents of intensive care.

What are the causes of respiratory muscle fatigue?

Most patients' respiratory muscle fatigue is caused by the disease itself. It has been found that sepsis, mechanical ventilation in multiple organ failure, hypercapnia (acidosis) and a variety of drugs can cause neuromuscular dysfunction, and become an important part of the pathological process of the above diseases.

Common symptoms: shortness of breath, abnormal breathing, abnormal breath. The respiratory rate is accelerated, the breathing is not synchronized (such as periodic abdominal pressure and chest pressure, alternating disordered and non parallel abdominal pressure breathing, abdominal bimodal breathing movement), and chest abdominal contradictory breathing.

Muscle relaxant prolongation is more common in patients with long-term or large-scale application of muscle relaxants, or in patients with neuromuscular dysfunction at the same time. The incidence rate in ICU is about 5%, which can prolong the length of ICU stay. The incidence of acute myopathy induced by NBA is lower than that of prolonged muscle relaxant effect, and it is most common in the acute attack of asthma when large dose of hormone and NBA are used at the same time.

matters needing attention

If respiratory muscle fatigue or functional failure plays an important role in the occurrence of respiratory failure, we should first correct and remove the causes of respiratory muscle dysfunction. The general principles are as follows: 1) to ensure adequate energy supply to respiratory muscles, including supplementing nutrition, correcting electrolyte abnormalities, especially phosphorus and magnesium abnormalities, correcting hypoxemia and hypercapnia, and improving cardiac output. ② Specific treatment for respiratory muscle fatigue, including nutrition supplement, respiratory muscle function exercise, respiratory muscle rest and so on.