Search results
Results From The WOW.Com Content Network
The respiratory quotient (RQ or respiratory coefficient) is a dimensionless number used in calculations of basal metabolic rate (BMR) when estimated from carbon dioxide production. It is calculated from the ratio of carbon dioxide produced by the body to oxygen consumed by the body, when the body is in a steady state.
In obstructive lung disease, the FEV1 is reduced due to an obstruction of air escaping from the lungs. Thus, the FEV1/FVC ratio will be reduced. [4] More specifically, according to the National Institute for Clinical Excellence, the diagnosis of COPD is made when the FEV 1 /FVC ratio is less than 0.7 or [8] the FEV 1 is less than 75% of predicted; [9] however, other authoritative bodies have ...
In respiratory physiology, the ventilation/perfusion ratio (V/Q ratio) is a ratio used to assess the efficiency and adequacy of the ventilation-perfusion coupling and thus the matching of two variables: V – ventilation – the air that reaches the alveoli; Q – perfusion – the blood that reaches the alveoli via the capillaries
TLC: Total lung capacity: the volume in the lungs at maximal inflation, the sum of VC and RV. TV: Tidal volume: that volume of air moved into or out of the lungs in 1 breath (TV indicates a subdivision of the lung; when tidal volume is precisely measured, as in gas exchange calculation, the symbol TV or V T is used.)
Doing spirometry. Spirometry (meaning the measuring of breath) is the most common of the pulmonary function tests (PFTs). It measures lung function, specifically the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled.
Minute ventilation (or respiratory minute volume or minute volume) is the volume of gas inhaled (inhaled minute volume) or exhaled (exhaled minute volume) from a person's lungs per minute. It is an important parameter in respiratory medicine due to its relationship with blood carbon dioxide levels. It can be measured with devices such as a ...
The partial pressure of carbon dioxide, along with the pH, can be used to differentiate between metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis. Hypoventilation exists when the ratio of carbon dioxide production to alveolar ventilation increases above normal values – greater than 45mmHg.
Once this is known, the total metabolic rate may be estimated from simplifying assumptions regarding the ratio of oxygen used in metabolism (and therefore heat generated), to carbon dioxide eliminated (see respiratory quotient). This quotient can be measured in other ways, and almost always has a value between 0.7 and 1.0, and for a mixed diet ...