CHEST Guidelines-To-Accept-or-Not-Accept-Dyscapnia

To-Accept-or-Not-Accept-Dyscapnia_chest

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The editorial titled "To Accept or Not Accept Dyscapnia That Is the Question" by Schultz, Morales-Quinteros, and Artigas-Raventos examines the complexities of mechanical ventilation in critically ill patients, specifically focusing on the management of dyscapnia—abnormal levels of CO2 during ventilation. The authors discuss historical shifts in ventilation practices, particularly the move from using large tidal volumes to low tidal volumes to protect against volutrauma, and explore the concept of 'permissive hypercapnia' where increased CO2 is tolerated to reduce lung injury. Despite understanding hypercapnia's potential harm from preclinical studies showing delayed lung repair and worse outcomes, recent large-scale data from the LUNG SAFE study suggests no significant mortality difference between normocapnic and hypercapnic patients in early ARDS. However, it does identify increased mortality in hypocapnic patients.<br /><br />The commentary stresses the importance of targeting normal arterial pH rather than specific CO2 levels, arguing that unregulated management could lead to adverse effects, suggesting caution specifically with hypocapnia. The authors note the necessity to consider individual patient circumstances, such as metabolic derangements, and how active patient behavior might inherently impact ventilation outcomes. They also highlight the prognostic significance of dead space in ARDS and call for its assessment in future research.<br /><br />Importantly, the editorial debates the impact of ventilation rates and mechanical power, advocating potentially reduced mechanical power through strategies like lowered respiratory rates, despite potential hypercapnia. The authors urge care in translating theoretical findings of patient self-inflicted lung injury into practice prematurely and recommend further investigation before any major changes are made in clinical practice, suggesting a nuanced approach to respiratory management that balances the mitigation of injury with adverse gas exchange states.

Keywords

dyscapnia

mechanical ventilation

permissive hypercapnia

ARDS

lung injury

tidal volumes

hypocapnia

dead space

mechanical power

respiratory management