What is the typical Inspiratory:Expiratory Ratio (I:E) setting for mechanical ventilation?

The typical Inspiratory:Expiratory Ratio (I:E) setting for mechanical ventilation is 1:2. This ratio reflects the physiology of normal breathing, where the expiratory phase occupies a longer duration than the inspiratory phase. In most patients, especially those with healthy lungs, expiration is typically twice as long as inspiration to allow for adequate gas exchange and to prevent air trapping.

This setting aids in maintaining optimal ventilation and ensures that the lungs have enough time to fully exhale, which is crucial in various respiratory conditions. Using an I:E ratio of 1:2 helps avoid complications such as hyperinflation and decreased venous return due to prolonged inspiratory times. Thus, for patients if starting on mechanical ventilation, utilizing a 1:2 ratio aligns with standard practice aimed at mimicking normal respiratory mechanics and supporting effective gas exchange.