Methacholine-induced fall in forced vital capacity as a marker of asthma severity

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 bec...

Exhaled breath 8-isoprostane as a marker of asthma severity

INTRODUCTION Oxidative stress is a non-specific feature of airway inflammation in asthmatics. 8-Isoprostane (8-IP), a prostaglandin-F(2α) isomer, is a relatively new marker of oxidative stress and may be measured in exhaled breath condensate (EBC) of patients with asthma. This research study aimed to evaluate the usefulness of EBC 8-IP as a marker of severity and control of severe adult asthma....

Forced Vital Capacity (FVC) and Forced Vital Capacity in 1 Second (FEV1) of Apparently Healthy Non-smoker Adult Obese

Forced vital capacity and forced expiratory volume in six seconds as predictors of reduced total lung capacity.

The present study aims to derive guidelines that identify patients for whom spirometry can reliably predict a reduced total lung capacity (TLC). A total of 12,693 lung function tests were analysed on Caucasian subjects, aged 18-70 yrs. Restriction was defined as a reduced TLC. Lower limits of normal (LLN) for TLC were obtained from the European Respiratory Society recommended reference equation...

Incomplete forced expiration - estimating vital capacity by a mathematical method.

BACKGROUND Vital capacity is a key parameter in the determination of lung function, usually assessed by means of a forced expiration maneuver. This maneuver can be exhausting, and patients often cannot complete it. OBJECTIVES This study evaluates a method to estimate forced vital capacity (FVC) based on the extrapolation of volume-time curves from forced expiration. METHODS The algorithm wa...