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ventilation indexAn obsolete value based on the ratio of pulmonary ventilation/minute divided by the vital capacity, which was supplanted by the respiratory quotient.
ventilation indexAbbreviation: VI.
1. A calculation used to determine the severity of respiratory illness (acute lung injury and/or respiratory distress syndrome) in critically ill patients. The VI is the partial pressure of arterial CO2 multiplied by the peak airway pressure multiplied by the rate of ventilation, all divided by 1000.
Symbolically, the ventilation index is calculated as follows: VI = [RR x (PIP − PEEP) × PaCo2]/1000.
2. In environmental science, a measure of air pollution based on the speed of the wind and the height of the column of air in which smoke or other pollutants mix.
See also: index