Diaphragm Ultrasound in Patients with Neuromuscular Disorders
Massimo Zambon in Ultrasound of the Diaphragm and the Respiratory Muscles, 2022
Neuromuscular disorders are a group of neurological diseases that can affect the muscles, the neuromuscular junction, the peripheral nerves and the motor neurons. Respiratory function can be affected progressively in muscular disorders. Diaphragm is the main inspiratory muscle that account for more than 80% of forced vital capacity in healthy persons. Ultrasound is a noninvasive radiological technique that can be used to assess diaphragm morphology and function in neuromuscular disorders. Current evidence and perspectives of DU use in patients with NMD are discussed.
Assessment for Rehabilitation of COVID-19
Wenguang Xia, Xiaolin Huang in Rehabilitation from COVID-19, 2021
Rehabilitation training for COVID-19 patients requires professional rehabilitation physicians to formulate exercise prescriptions based on patients’ specific conditions. The formulation of exercise prescription depends on systematic assessment for rehabilitation, which should run through the whole process of rehabilitation treatment. The system of rehabilitation assessment for COVID-19 patients mainly includes assessments for respiratory function, physical function, and psychosocial function. The examination results can determine the degree and type of lung damage caused by the disease, helping clinicians make accurate diagnoses and develop scientific treatment plans. Lung volume includes tidal volume, inspiratory reverse volume, inspiratory capacity, vital capacity, residual volume, functional residual capacity, and total lung capacity, among which vital capacity is the most commonly used. Vital capacity of healthy adults varies greatly depending on genders, ages, body types, and exercises. Common clinical indexes are maximum ventilatory volume, forced vital capacity, or forced expiratory volume.
Demographics, Biology, and Physiology
K. Rao Poduri in Geriatric Rehabilitation, 2017
Biological causes that are age related include cardiac and pulmonary function, muscle strength, vital capacity, orthostatic changes, peripheral resistance, vital capacity, minute volume, and aerobic capacity. Psychological factors include beliefs about self, recovery, and rehabilitation in addition to delayed learning pace needing more repetitions. In the social arena, less frequent referrals to needed rehabilitative care, negative views of ageism, financial barriers, and self-ageism all impact the older adults in coping with disability and obtaining rehabilitation. The onset of aging along with the rate and extent of progression is very individualized and differs from individual to individual. Depending on the functional capacity, the biological age is the metric for the biology of aging, and not the chronological age. There are evolutionary, genetic, physiologic, and other theories of aging. The adrenal glands respond to aging with a decrease in aldosterone secretion that can explain the orthostatic hypotension experienced by aging population.
A Method for Assessing Small Airways Independent of Inspiratory Capacity
Published in Archives of Environmental Health: An International Journal, 1996
Aroonwan Preutthipan, Robert Frank, Gail Weinmann
Reduced forced vital capacity may confound assessment of small-airway function. In 17 healthy and 16 asthmatic volunteers, we validated a method for measuring mean expiratory flow during the middle half of the forced vital capacity, mean expiratory flow during the third quarter of the forced vital capacity, instantaneous forced expiratory flow at 50% of forced vital capacity, and instantaneous expiratory flow at 75% of forced vital capacity. These measurements were conducted at the same absolute lung volume (isovolume) when forced vital capacity was reduced voluntarily to 100%, 85%, and 75% of maximum, and the variances, expressed as the coefficients of variations, were compared. Absolute lung volumes above residual volume were determined with two reference spirograms: 100% and 75% forced vital capacity. In normals, means of flow rates at the same absolute lung volume did not differ with the three forced vital capacities, regardless of whether the 100% or 75% forced vital capacity served as the reference spirogram. Reduced forced vital capacity among asthmatics was associated with modest increases in isovolume flow rates, an effect that may underestimate airway narrowing. Intrasubject variability was least among volume-averaged flow rates (e.g., mean expiratory flow during the middle half of the forced vital capacity). Volume-adjusted flow rates can be used to assess small-airways narrowing when forced vital capacity is reduced, and volume-averaged rates provide the least variability.
Spirometric Studies in Non-Smoking, Healthy Adults
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 1982
A. A. Viljanen, P. K. Halttunen, K.-E. Kreus, B. C. Viljanen
Reference spirometric values for vital capacity (VC), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory volume in one second as percentage of vital capacity or of forced vital capacity (FEV%), the highest flow during forced inspiration (V˙max insp), the highest forced expiratory flow at 50% vital capacity (V˙max 50%), the highest forced expiratory flow when 75% of vital capacity has been expired (V˙max 25%), V˙max insp/V˙max 50% and peak expiratory flow (PEF) were determined in a series of 296 males and 257 females, 18–65 years old, who have never smoked. Equations were derived using height and age as predictors. The reproducibility was tested.
Pulmonary Function of Nonsmoking Female Asbestos Workers Without Radiographic Signs of Asbestosis
Published in Archives of Environmental Health: An International Journal, 1998
Xiao-Rong Wang, Eiji Yano, Koichi Nonaka, Mianzheng Wang, Zhiming Wang
Researchers disagree about whether exposure to asbestos causes significant respiratory impairments and airway obstruction in the absence of radiographic asbestosis and smoking. To obtain confirmatory information, the authors examined pulmonary function of 208 nonsmoking female asbestos workers who did not have asbestosis and 136 controls. The authors observed an overall lower single-breath carbon monoxide diffusing capacity in the asbestos workers than in controls. In addition, significant decreases in percentage vital capacity, percentage forced vital capacity, and percentage mean forced expiratory flow during the middle half of the forced vital capacity were evident in the older workers. Logistic regression analysis revealed that asbestos exposure was associated with abnormal single-breath carbon monoxide diffusing capacity, vital capacity, and mean forced expiratory flow during the middle half of the forced vital capacity among the older workers. The age-related decline in vital capacity, forced vital capacity, and mean forced expiratory flow during the middle half of the forced vital capacity was significantly greater in the asbestos workers than the controls. The findings imply that asbestos-exposure per se contributes predominantly to restricted lung volume and reduced single-breath carbon monoxide diffusing capacity. Asbestos may also cause slight airway obstruction, especially in workers who are heavily exposed.
Related Knowledge Centers
- Functional Residual Capacity
- Spirometry
- Inhalation
- Myasthenia Gravis
- Tidal Volume
- Lung Volumes
- Respiratory Disease