Caregivers' knowledge, attitudes, and practices regarding postpartum depression: a cross-sectional study.

Sarcopenia, an age-related syndrome characterized by progressive loss of overall muscle mass and function, is a major determinant of frailty, disability, and mortality in older adults. A distinct yet often underrecognized subtype termed respiratory sarcopenia, involves the specific deterioration of respiratory muscle mass and strength. Early identification of respiratory sarcopenia is clinically paramount, as it serves as an independent predictor of poor clinical outcomes in various chronic cardiopulmonary conditions and aging itself. However, respiratory sarcopenia lacks standardized and sensitive method for its early identification. Current screening paradigms of respiratory sarcopenia are indirect and have limitations. Handgrip strength (HGS) is widely used to screening overall sarcopenia, which does not specifically capture respiratory muscle impairment. While maximal inspiratory and expiratory pressures (MIP and MEP) are the standard measurements of global respiratory muscle strength, they are effort-dependent and can mask early or subclinical diaphragm dysfunction due to compensatory use of accessory muscles. Given that the diaphragm is responsible for majority of inspiratory work, early screening of its function is crucial for respiratory sarcopenia. However, a validated, noninvasive screening tool remains an unmet clinical need. Diaphragm ultrasound has emerged as a practical, radiation-free, non-invasive bedside technique capable of evaluating both structure and function of respiratory muscle. While conventional parameters such as thickness and excursion demonstrate established correlations with respiratory muscle strength, their predominantly static or displacement-based nature often lacks the sensitivity required to detect subtle functional decline, underscoring the necessity for advanced methodological protocols. To address this limitation, recent advancements emphasize the critical evaluation of dynamic contractility and relaxation. Consequently, dynamic parameters derived from the sniffing maneuver—a rapid, forceful nasal inhalation, provoking near-maximal diaphragm contraction, analogous to phrenic nerve stimulation—provide a more sensitive measurement of respiratory muscle strength, especially the excursion velocity during maximum voluntary sniffing (V) and the diaphragm maximal relaxation rate obtained with ultrasound (ECHO-MRR). However, the independent predictive value of these advanced parameters for both respiratory and overall muscle strength remains underexplored.