Slow vital capacity

Abstract

Forced vital capacity (FVC) and slow vital capacity (SVC) are non-invasive tests of respiratory function. Although FVC has been extensively studied and is used in most PFT (pulmonary function test) labs, SVC can also be used in clinical practice as it is a more comfortable and convenient test to perform. SVC-based diagnostic criteria can lead to earlier detection of obstructive lung disease. In contrast to FVC, SVC is less affected by respiratory muscle fatigue, airflow patency, expiratory muscle weakness and air leakage making it an appropriate test of respiratory function in patients of amyotrophic lateral sclerosis (ALS) and other neuromuscular disorders. As respiratory insufficiency is the major cause of mortality in ALS patients, regular SVC measurement provides the respiratory functional status, so that early treatment can be started which improves the survival and quality of life in these patients. The purpose of this article is to highlight the importance of considering SVC in clinical practice.

Effects of Scalene Muscle Stretching on Slow Vital Capacity and Chest Expansion in Patients After Coronary Artery Bypass Grafting: An Interventional Study

“…Therefore, if the scalene muscles become shorter, the extent of thoracic lift decreases during inhalation, thus potentially decreasing inhalation volume [14]. Because median sternotomy is associated with short-term pulmonary impairment, pulmonary function can be measured both pre-and postoperatively [15][16][17][18]. Pulmonary function tests (PFTs) are a group of non-invasive diagnostics used to evaluate lung function.…”

“…Pulmonary function tests (PFTs) are a group of non-invasive diagnostics used to evaluate lung function. Forced vital capacity (FVC) and SVC are two means of evaluating vital capacity, both of which are major components of PFTs [15][16][17][18]. SVC can be determined during either a slow, mild maximal expiration after a maximal inspiration, or a maximal inspiration after a slow, gentle maximal expiration [15].…”

“…Forced vital capacity (FVC) and SVC are two means of evaluating vital capacity, both of which are major components of PFTs [15][16][17][18]. SVC can be determined during either a slow, mild maximal expiration after a maximal inspiration, or a maximal inspiration after a slow, gentle maximal expiration [15]. Both the FVC and SVC manoeuvres are performed at least three times and no more than eight times during a PFT [15].…”

“…SVC can be determined during either a slow, mild maximal expiration after a maximal inspiration, or a maximal inspiration after a slow, gentle maximal expiration [15]. Both the FVC and SVC manoeuvres are performed at least three times and no more than eight times during a PFT [15]. Over the site of the median sternotomy after CABG, patients may experience incisional pain, which may be exacerbated by a forced vital capacity test.…”