CHEST Guidelines-Paradoxically-Improved-Respiratory-Compliance-With

Paradoxically-Improved-Respiratory-Compliance-With

Pdf Summary

The letter to the editor discusses an unexpected phenomenon observed in patients with severe COVID-19 ARDS. Normally, increasing intraabdominal pressure (IAP) would elevate the plateau airway pressure (Pplat) and reduce respiratory system compliance (Crs). However, several COVID-19 ARDS patients exhibited a counterintuitive response where abdominal compression decreased Pplat and increased Crs. This was first observed in a 58-year-old woman with severe ARDS due to COVID-19. Upon abdominal compression, a decrease in Pplat was noted, contrary to traditional expectations. This response was consistently reproduced in six additional patients who were deeply sedated and pharmacologically paralyzed. <br /><br />The phenomenon seems particularly evident in the late phases of COVID-19 ARDS, characterized by stiff lung mechanics, and raises questions about conventional understanding of ARDS measurement techniques and treatment strategies. The authors speculate that the compression may decrease end-expiratory lung volume, allowing overdistended lung units to function more efficiently. Supporting this hypothesis, these patients showed a notable decrease in Pplat following a PEEP reduction, suggesting that tidal ventilation exceeded upper inflection points of the pressure-volume curve.<br /><br />This report proposes that observing Pplat response to abdominal compression could indicate end-inspiratory overdistention—a potential sign to adjust ventilation settings, such as reducing tidal volume or PEEP. The findings are significant for clinical practice, especially in resource-limited settings, and suggest areas for future research. The applicability of this clinical observation could guide safer ventilation practices, offering a potentially simple and cost-effective tool amidst the COVID-19 pandemic.

Keywords

COVID-19 ARDS

intraabdominal pressure

plateau airway pressure

respiratory system compliance

abdominal compression

lung mechanics

ventilation settings

end-expiratory lung volume

pressure-volume curve

clinical practice