High-intensity noninvasive ventilation was first used more than 20 years ago in patients with chronic obstructive pulmonary disease (COPD) and chronic hypercapnia. High-intensity noninvasive ventilation aims to achieve normocapnia or to reduce elevated Paco2 levels to the maximally achievable extent. For this purpose, the driving pressure, mainly achieved by modifying the inspiratory positive airway pressure, is individually titrated by a stepwise increase until normocapnia is established or the tolerated maximum pressure is reached (20-30 cm H2O). This approach is in clear contrast to the classic approach of low-intensity noninvasive ventilation (<18 cm H2O). Randomized crossover trials have established the physiological superiority of high-intensity vs low-intensity noninvasive ventilation in the chronic setting.
