Millions of critically ill patients require mechanical ventilation each year, and for each of those patients, clinicians must choose a mode of ventilation.1 Ventilator modes are preselected patterns of controlled and dependent variables that determine how positive-pressure breaths are delivered.2,3 Many factors potentially influence how modes are selected: institutional and hospital unit culture, ventilator brand and mode availability, patient characteristics, and clinician preference all affect mode choice. Unfortunately, few data exist to inform these decisions. Most patients in routine clinical care receive a volume-targeted mode using either volume control–continuous mandatory ventilation (VC-CMV) or adaptive pressure control–continuous mandatory ventilation (APC-CMV).4,5 In VC-CMV, the ventilator delivers a set tidal volume, fixed inspiratory flow, and variable inspiratory pressure. In APC-CMV, the ventilator sets an algorithmically determined inspiratory pressure predicted to deliver a target tidal volume, and the tidal volume is not directly controlled. The ventilator adjusts the inspiratory pressure from breath to breath until the target tidal volume is achieved at the lowest inspiratory pressure. VC-CMV remains the most common ventilator mode worldwide, but APC-CMV use has increased due to perceived ease of use, decreased alarm …

Correspondence: Kevin W Gibbs MD, 2nd Floor Watlington Hall. Section on Pulmonary, Critical Care, Allergy, and Immunology, Medical Center Boulevard, Winston-Salem, North Carolina 27157. E-mail: kgibbswakehealth.edu