Measurement of respiratory muscle function

Respiratory muscle function measurement is a lung function test program used to evaluate respiratory muscle fatigue or respiratory failure, assist in diagnosis and guide treatment. People who need to be examined: abnormal breathing, shortness of breath, chest pain, and pulmonary dysfunction. Basic Information Specialist classification: Respiratory examination classification: pulmonary function test Applicable gender: whether men and women apply fasting: not fasting Tips: In order to ensure that the TTdi is constant, the subject must observe the pressure waveform on the oscilloscope so that it can be adjusted at any time while breathing according to the metronome. Normal value 1. Respiratory muscle strength (RMS) refers to the maximum contractile capacity of the respiratory muscles. The main indicators are 1 Maximum Inspiratory Pressure (MIP) and Maximum Expiratory Pressure (MEP) It is a measure of the strength of all inspiratory and expiratory muscles. Male MIP = 143-0.55 x age, MEP = 268-1.03 x age. Female MIP = 104-0.51 × age, MEP = 170-0.53 × age, the unit is cmH2O. (1 cm H2O ≈ 0.098 kPa). 2 PDI and Pdimax of normal people have a Pdimax of 90-215 cmH2O. 2. Respiratory muscle endurance (RME) refers to the ability of the respiratory muscle to maintain a certain level of ventilation. The main indicators are 1 Maximum autonomous ventilation (MVV) and maximum maintenance ventilation (MSVC). Normal people have about 104L for MVV and about 82L for women. MSVC refers to the amount of ventilation that can maintain a 15 min 60% MVV action. The walking distance of 212 min is affected by many factors, and the measured value changes greatly. 3 膈 muscle tension-time index (TTdi) is about 0.02 in normal people when breathing calmly. 4 The diaphragmatic electromyography (EMG) median frequency (FC) is between 70 and 120, and the high frequency component (H) / low frequency component (L) is between 0.3 and 1.9. 5膈 nerve electrical stimulation method Pdi/Pdimax is 17% to 21%. 6 monitoring of respiratory patterns The normal breathing pattern is chest or abdominal breathing. Clinical significance Abnormal result (1) The MIP of patients with chronic obstructive pulmonary disease is lower than that of normal people. There is no significant change in MEP measurement, and the RME measurement is reduced, and it is more obvious than RMS reduction. (2) MIP can be used as an indicator of whether mechanical ventilation and whether it can be taken offline in patients with chronic obstructive pulmonary disease and respiratory failure. It is generally believed that when MIP is less than 30% of the normal predicted value, respiratory failure is easy to occur; when MIP cannot reach -1.96 kPa (-20 mmHg), mechanical ventilation assistance is required; and for patients who have applied mechanical ventilation, if MIP cannot reach the above index, it is often Difficult to go offline. (3) When both Pdi and Pdimax are significantly decreased, it is considered to have diaphragmatic fatigue, which is more common in patients with severe chronic obstructive pulmonary disease and neuromuscular diseases. (4) Determination of respiratory muscle function and can be used as an objective indicator to evaluate the effects of respiratory muscle exercise and drug treatment on respiratory muscle function. Low results may be diseases: adult respiratory distress syndrome, emphysema precautions Before inspection: In order to ensure that the TTdi is constant, the subject must be observed by himself to observe the pressure waveform on the oscilloscope so that it can be adjusted at any time while breathing according to the metronome. When checking: (1) MIP and MEP should be determined multiple times due to gender, age and subjects' subjective effort factors. In three measurements, the data should be less reliable when the error should be less than 20%. (2) Pdimax is affected by the initial length before contraction and lower at high lung capacity. Therefore, it is generally measured at the functional residual gas position. After inspection: (1) Analysis of EMG must remove interference from ECG and low frequency components. (2) Stimulation electrodes and functional residual gases may affect Pdi/Pdimax results. Inspection process First, prepare: 1. Prepare the instrument and strictly disinfect it before measuring. 2. The patient's condition, diagnosis and clinician's application purpose should be known before the test. . 3. Prepare necessary emergency medicines, equipment, oxygen, etc. for emergency use. 4. Introduce the purpose and method to the patient and obtain the cooperation of the patient. Second, measure its maximum inspiratory, expiratory pressure, diaphragmatic function. Not suitable for the crowd 1. Need the most forceful examination, should not be used for patients with pneumothorax, intracranial hypertension and intracranial hemorrhage. 2. Need to place the esophagus and gastric cyst tube examination, should not be used for esophageal obstruction, gastric perforation, upper gastrointestinal bleeding and dysphagia. 3. Magnetic wave stimulation The sacral nerve method should not be applied to people with seizures, intracranial injuries and the installation of pacemakers or other pacemakers. Adverse reactions and risks Generally no complications and harm.