volumecontrolled

Volume-controlled, in the context of mechanical ventilation, refers to a mode in which breaths are delivered with a pre-set tidal volume. It is also called volume-targeted ventilation and is commonly used in intensive care and anesthesia settings.

In volume-controlled ventilation, the caregiver programs the ventilator with a specific tidal volume (for example, about 6 to 8 milliliters per kilogram of predicted body weight), along with other parameters such as respiratory rate, inspiratory time, positive end-expiratory pressure (PEEP), and fraction of inspired oxygen (FiO2). The ventilator delivers breaths to achieve the target tidal volume. However, the pressure required to deliver that volume can vary with changes in lung compliance and airway resistance. Leaks or patient effort can also affect the actual tidal volume.

Advantages of this mode include consistent control of minute ventilation and more predictable carbon dioxide elimination, which aids in CO2 management. It is particularly useful when precise tidal volumes are desired, such as during lung-protective strategies. Limitations include the potential for high peak airway pressures if the patient’s lung compliance worsens, increasing the risk of volutrauma or barotrauma. Continuous monitoring of plateau pressure and driving pressure (plateau minus PEEP) helps manage these risks.

Volume-controlled ventilation is often contrasted with pressure-controlled ventilation, where the airway pressure is set and the delivered tidal volume varies with lung mechanics. Clinicians choose modes based on patient condition, goals for gas exchange, and tolerance of airway pressure, adjusting settings to balance ventilation with lung protection.