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Results for “VITAL CAPACITY”

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At least 19 recordsLinked to original sources
PubMed1998

Forced vital capacity, slow vital capacity, or inspiratory vital capacity: which is the best measure of vital capacity?

Vital capacity can be measured as forced vital capacity (FVC), slow vital capacity (SVC), and inspiratory vital capacity (IVC). Although it is well known that the latter two are generally greater, a systematic comparison of the three in subjects with different degrees of airways obstruction has not been made. Sixty asthmatics and 20 normal subjects performed maneuvers for measurement of FVC, SVC, and IVC on a dry, rolling-seal spirometer. The severity of airways obstruction in asthmatics was classified as mild, moderate, and severe. There was no significant difference between FVC, SVC, and IVC in normal subjects. However, the three measurements of vital capacity were significantly different in all subgroups of asthmatics. FVC was smaller than both SVC and IVC. The differences were more marked in patients with moderate and severe degrees of airways obstruction. The differences between SVC and IVC were small and clinically not important. Forced expiratory volume in 1 sec (FEV1) expressed as percent of FVC, SVC, and IVC, was not different in normals and asthmatics with mild airways obstruction. The ratios were significantly different in asthmatics with moderate and severe airways obstruction. FEV1/IVC ratio was the lowest in both the groups followed by FEV1/SVC and FEV1/FVC. IVC and SVC are greater than FVC in patients with airways obstruction. This difference increases as the degree of obstruction increases. The difference between SVC or IVC and FVC serves as an indicator of air trapping. Both FVC and IVC could be measured and the largest VC used to calculate the FEV1/VC ratio because this increases the sensitivity of spirometry in detecting airways obstruction.

Adult↗
PubMedDate not supplied

Maximum insufflation capacity: vital capacity and cough flows in neuromuscular disease.

OBJECTIVE: To investigate the relationships between vital capacity (VC), maximum insufflation capacity (MIC), and both unassisted and assisted peak cough flows (PCFs). DESIGN: The 108 patients were divided into two groups, those whose MICs were greater than their VCs (group 1) and those whose MICs could not exceed their VCs (MIC = VC, or group 2). RESULTS: The MIC correlated positively with the VC for group 1 patients, but the percent increase in MIC correlated negatively with VC. Both VC and MIC correlated significantly with both unassisted and assisted PCF, respectively. Assisting the cough increased the PCF of 37 patients over a previously defined critical level of 2.7 L/sec. The MIC VC difference and percent increase in MIC also correlated significantly with the difference between unassisted and assisted PCF. Although the group 2 patients did not have true cough flows because of inability to close the glottis, their peak expiratory flows were significantly less than the unassisted and assisted PCF of the group 1 patients. CONCLUSIONS: The greater the MIC VC difference, the greater the PCF, and, thereby, the ability to expel airway mucus and avert respiratory complications. The lower the VC, the greater the percent increase in MIC and the greater the percent increase in assisted PCF. Maximal insufflations are extremely important to increase PCF for patients with neuromuscular conditions who have VCs of < 1500 ml.

Adult↗
PubMed1987

Continuous positive airway pressure effect on functional residual capacity, vital capacity and its subdivisions.

Thirty-four otherwise healthy patients having to undergo elective upper abdominal surgery were randomly assigned to two equal groups. In the treatment group, constant positive airway pressure (CPAP) with an expiratory pressure of 12 cm H2O was applied at one hour following extubation, and at daily intervals for the first five days following surgery for a continuous period of three hours. The control group received no CPAP treatment. All patients were given postoperative physiotherapy. In patients who received postoperative CPAP with an end-expiratory pressure of 12 cm H2O, marked normalization of pulmonary function was noted.

Abdomen↗
PubMed1984

Inspiratory and expiratory vital capacity.

Vital capacity (VC) is frequently measured by two different methods (inspiration vs expiration). The difference in results is not readily available in the literature. The VC was measured both ways in 60 subjects, including many with obstructive airway disease. Only a minor difference in mean VC (75 +/- ml SD) was found. The methods are probably interchangeable.

Aged↗
PubMed1983

[Effect of regular training on total and vital capacity of the lung in 17 to 25-year-old rowers].

Lung volumes, FEV1 and airway resistance have been repeatedly measured from age 17 to 26 in a group of 16 rowers. Total capacity, vital capacity and FEV1 are in the upper normal range. Airway resistance is normal. The increase in total and vital capacity from age 17 to 26 has been within the normal limits of other young men in the same age group. Intensive training does not appear to influence total and vital capacity once the final height has been reached. Top Swiss rowers of the years 1981 and 1982 have total and vital capacity values well above the predicted values for men of the same height and age, and also above those measured in top Swiss rowers of the period 1968-1972. The latter finding can be explained by a difference in the selection process.

Adolescent↗
PubMedDate not supplied

The relationship between delta-forced vital capacity (percent fall in forced vital capacity at the PC20 dose of methacholine) and the maximal airway response in patients who have mild asthma.

Airway hypersensitivity is routinely evaluated by measuring the concentration (PC20) of inhaled methacholine or histamine that causes a 20% fall in forced expiratory volume in 1 second (FEV1). It has been suggested that a percentage fall in forced vital capacity (FVC) measured at the PC20 dose of inhaled agonist (deltaFVC) is a potentially useful clinical measure in patients who have asthma because it provides indirect information about gas trapping and therefore the maximal airway response. The relationships between serum eosinophil cationic protein (ECP) levels and the maximal airway response or deltaFVC are largely unknown. The aims of this study were to determine whether deltaFVC is correlated with the degree of maximal airway response and to examine the relationships between serum ECP and deltaFVC or maximal airway response in patients who have mild asthma. Fifty-eight patients with mild asthma underwent high-dose methacholine challenge testing. The PC20, maximal airway response, and deltaFVC were measured on the methacholine dose-response curves. Serum ECP levels also were determined. Subjects without a maximal response plateau (n = 33) had a significantly higher level of deltaFVC (17.9 +/- 4.1%) than subjects with a plateau (n = 25; 14.9 +/- 4.8%). A significant correlation was found between deltaFVC and the level of maximal response plateau (r = 0.446; p = 0.026). Not only methacholine PC20 but also maximal airway response or deltaFVC had no relationships with serum ECP levels. Our results suggest that deltaFVC can be used as a surrogate marker of maximal airway response in patients who have mild asthma and that neither maximal airway response nor deltaFVC reflects blood eosinophil activation any more than methacholine PC20.

Adolescent↗