Measurement of respiratory system resistance during mechanical ventilation.

Abstract

The measurement of respiratory system resistance during mechanical ventilation is important to ascertain the causes of increase in airway pressure during volume-controlled ventilation, which may include airways resistance and decreased respiratory system compliance. Separation of total resistance from compliance of the respiratory system can be assessed by the end-inspiratory hold maneuver that separates peak pressure from plateau pressure. Although this method assumes a homogeneous respiratory system, it has proven useful clinically to separate flow-dependence issues such as bronchospasm or endotracheal tube obstruction from stiff lungs (acute lung injury) or decrease chest wall (abdominal distension) compliance.