Respiratory pump failure is a condition which the respiratory system can not meet the metabolic demand because of the inability of respiratory muscles to ventilate the lungs without any pulmonary pathology. Two cases of respiratory pump failure(myasthenia gravis and Guillian-Barre syndrome) had been treated with controlled and assisted ventilation using the Bennet MA II ventilator. Large tidal volume with high peak flow rate was given to permit leakage of gases during inspiration when the patients were ventilated with CMV with asaistance. This made the patients capable of communicating with persons by phonation which was the greatest advanage of this mode of assisted ventilation.
Gases ; Humans ; Lung ; Pathology ; Phonation ; Respiratory Muscles ; Respiratory System ; Tidal Volume ; Ventilation ; Ventilators, Mechanical

The function of inspiratory muscles is crucial for effective cough as well as expiratory muscles in patients with Duchenne muscular dystrophy (DMD). However, there is no report on the correlation between cough and inspiratory muscle strength. To investigate the relationships of voluntary cough capacity, assisted cough techniques, and inspiratory muscle strength as well as expiratory muscle strength in patients with DMD (n=32). The vital capacity (VC), maximum insufflation capacity (MIC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were measured. Unassisted peak cough flow (UPCF) and three different techniques of assisted PCF were evaluated. The mean value of MICs (1918 +/- 586 mL) was higher than that of VCs (1474 +/- 632 mL) (p < 0.001). All three assisted cough methods showed significantly higher value than unassisted method (212 +/- 52 L/min) (F = 66.13, p < 0.001). Combined assisted cough technique (both manual and volume assisted PCF; 286 +/- 41 L/min) significantly exceeded manual assisted PCF (MPCF; 246 +/- 49 L/ min) and volume assisted PCF (VPCF; 252 +/- 45 L/min) (F = 66.13, p < 0.001). MIP (34 +/- 13 cmH2O) correlated significantly with both UPCF and all three assisted PCFs as well as MEP (27 +/- 10 cmH2O) (p < 0.001). Both MEP and MIP, which are the markers of respiratory muscle weakness, should be taken into account in the study of cough effectiveness.
Respiratory Muscles/*pathology ; Pressure ; *Oxygen Consumption ; Muscular Dystrophy, Duchenne/*genetics ; Muscles/pathology ; Muscle Weakness/pathology ; Models, Statistical ; Male ; Inspiratory Capacity ; Humans ; Cough ; Biopsy ; Adult ; Adolescent

OBJECTIVETo investigate the effect of tumor necrosis factor-α (TNF-α) on nutritional status and proteolysis of respiratory muscle in a rat model of chronic obstructive pulmonary disease (COPD).

METHODSNinety healthy male adult Wistar rats were randomly divided into model group (A) and normal control group (B). COPD malnutrition rat models were established by cigarettes smoke and nutrient limitation and divided into normal nutrition COPD group (A(1)), malnutrition COPD group (A(2)), and malnutrition COPD intervention group (A(3)). In group A(3), the rats received intravenous injection of TNF-α mAb (0.1 mg/kg). TNF-α levels in the serum and respiratory muscle homogenates were measured using enzyme-linked immunosorbent assay (ELISA), and plasma levels of glucose, albumin, and triglyceride were measured with an automatic biochemistry analyzer. High-performance liquid chromatography was used to measure the contents of 3-methylhistidine and tyrosine in the respiratory muscle homogenates.

RESULTSThe serum TNF-α level and plasma levels of glucose and triglyceride were significantly higher but the plasma albumin level was significantly lower in group A(2) than in groups B, A(1), and A(3) (P<0.01). The contents of 3-MH and Tyr in the respiratory muscle homogenates were significantly higher in group A(2) than in the other 3 groups (P<0.01, P<0.01). TNF-α in the respiratory muscle showed a strong positive correlation to 3-MH and Tyr.

CONCLUSIONTNF-α is one of the causes of increased proteolysis of the respiratory muscle.

Animals ; Lung ; pathology ; Male ; Nutritional Status ; Proteolysis ; Pulmonary Disease, Chronic Obstructive ; metabolism ; pathology ; Rats ; Respiratory Muscles ; metabolism ; Tobacco Products ; Tumor Necrosis Factor-alpha ; pharmacology

Critical illness myopathy (CIM) is characterized by generalized flaccid weakness occurring in patients with severe systemic illness. A 27-year-old woman presented with loss of consciousness and dyspnea. The brain MRI suggested Wernicke's encephalopathy. During treatment, she experienced progressive quadriparesis and respiratory muscle weakness, which required the mechanical ventilation. The muscle pathology of vastus lateralis revealed type 2 muscle fiber atrophy on histochemical stain and selective loss of myosin on electron microscopic study, and suggested clinical diagnosis of critical illness myopathy.
Adult ; Atrophy ; Brain ; Critical Illness* ; Diagnosis ; Dyspnea ; Female ; Humans ; Magnetic Resonance Imaging ; Muscular Diseases* ; Myosins ; Pathology ; Quadriceps Muscle ; Quadriplegia ; Respiration, Artificial ; Respiratory Muscles ; Unconsciousness ; Wernicke Encephalopathy

PURPOSE: The purpose of this study is to investigate how respiratory muscle strength correlates to cough capacity in patients with respiratory muscle weakness. MATERIALS AND METHODS: Forty-five patients with amyotrophic lateral sclerosis (ALS), 43 with cervical spinal cord injury (SCI), and 42 with Duchenne muscular dystrophy (DMD) were recruited. Pulmonary function tests including forced vital capacity (FVC) and respiratory muscle strength (maximal expiratory pressure, MEP; maximal inspiratory pressure, MIP) were performed. The correlation between respiratory muscle strength and cough capacity was analyzed. RESULTS: In the SCI group, FVC in a supine position (2,597 +/- 648 mL) was significantly higher than FVC in a sitting position (2,304 +/- 564 mL, p < 0.01). Conversely, in the ALS group, FVC sitting (1,370 +/- 604 mL) was significantly higher than in supine (1,168 +/- 599 mL, p < 0.01). In the DMD group, there was no statistically significant difference between FVC while sitting (1,342 +/- 506 mL) and FVC while supine (1,304 +/- 500 mL). In addition, the MEP and MIP of all three groups showed a significant correlation with peak cough flow (PCF) (p < 0.01, Pearson's correlation analysis). In the SCI group, MIP was more closely correlated with PCF, while in the ALS and DMD groups, MEP was more closely correlated with PCF (p < 0.01, multiple regression analysis). CONCLUSION: To generate cough flow, inspiratory muscle strength is significantly more important for SCI patients, while expiratory muscle function is significantly more important for ALS and DMD patients.
Adult ; Amyotrophic Lateral Sclerosis/*physiopathology ; Cough/*physiopathology ; Female ; Humans ; Inspiratory Capacity ; Male ; Middle Aged ; Muscle Strength/*physiology ; Muscle Weakness/pathology/*physiopathology ; Muscular Dystrophy, Duchenne/*physiopathology ; Respiratory Muscles/pathology/*physiopathology ; Spinal Cord Injuries/*physiopathology

Previous studies have demonstrated a positive association between obesity and decreased lung function. However, the effect of muscle and fat has not been fully assessed, especially in a healthy elderly population. In this study, we evaluated the impact of low muscle mass (LMM) and LMM with obesity on pulmonary impairment in healthy elderly subjects. Our study used data from the Korea National Health and Nutrition Examination Survey from 2008 to 2011. Men and women aged 65 yr or older were included. Muscle mass was measured by dual-energy X-ray absorptiometry. LMM was defined as two standard deviations below the sex-specific mean for young healthy adults. Obesity was defined as body mass index > or = 25 kg/m2. The prevalence of LMM in individuals aged over 65 was 11.9%. LMM and pulmonary function (forced vital capacity and forced expiratory volume in 1 second) were independently associated after adjusting for age, sex, body mass index, smoking status, alcohol consumption, and frequency of exercise. LMM with obesity was also related to a decrease in pulmonary function. This study revealed that LMM is an independent risk factor of decreased pulmonary function in healthy Korean men and women over 65 yr of age.
Age Distribution ; Aged ; Aged, 80 and over ; Causality ; Comorbidity ; Female ; Humans ; Lung Diseases/*epidemiology/*pathology ; Male ; Nutrition Surveys ; Obesity/*epidemiology/pathology ; Organ Size ; Prevalence ; Reference Values ; Reproducibility of Results ; Republic of Korea/epidemiology ; Respiratory Function Tests ; Respiratory Muscles/*pathology ; Risk Factors ; Sarcopenia/*epidemiology/*pathology ; Sensitivity and Specificity ; Sex Distribution