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The following is a summary of “Effects on mechanical power of different devices used for inhaled sedation in a bench model of protective ventilation in ICU,” published in the January 2024 issue of Critical Care by Pellet et al.

Researchers started a retrospective study investigating the effect of inhaled sedation devices on mechanical power (MP) in patients with acute respiratory distress syndrome (ARDS), considering its impact on CO₂ removal and potential lung injury.

They assessed and compared the impact of three inhaled sevoflurane delivery devices (AnaConDa-50 mL (ANA-50), AnaConDa-100 mL (ANA-100), and MIRUS) in the ICU, evaluating MP on a test lung model with compliances of 20, 40, and 60 mL/cmH₂O. Simulating lung-protective ventilation with low tidal volume and positive end-expiratory pressure (5 and 15 cmH₂O), respiratory rate, or tidal volume in 15% steps until EtCO₂ returned to baseline, calculating MP before and after EtCO₂correction using a simplified equation in ambient conditions.

The results showed a significantly more significant EtCO₂increase with MIRUS (+78 ± 13%) and ANA-100 (+100 ± 11%) compared to ANA-50 (+49 ± 7%) following device insertion. After normalizing EtCO₂ by adjusting minute ventilation, MP increased by over 50% with all inhaled sedation devices compared to controls, with the lowest increase observed with ANA-50 (P<0.05 versus ANA-100 and MIRUS). The Costa index, evaluating mechanical energy (driving pressure × 4 + respiratory rate) delivered to the lungs, increased by more than 20% in all conditions. Additional experiments confirmed a >50% MP increase with all devices after normalizing EtCO₂ by adjusting minute ventilation.

Investigators concluded that inhaled sedation devices significantly increased MP, potentially hindering their use for ARDS patients.

Source: annalsofintensivecare.springeropen.com/articles/10.1186/s13613-024-01245-x