The aim of this study is to report the proportion of patients with acute hypoxemic respiratory failyre (AHRF) undergoing mechanical ventilation who exceed 17 J/min of mechanical power (MP) and the difference in terms of proinflammatory cytokine concentration in blood samples and bronchoalveolar lavage.

The main questions it aims to answer are:

1. Which is the proportion of patients who exceed 17 J/min of mechanical power (MP) during the first 72 hours of mechanical ventilation?
2. Is there a difference in terms of cytokine concentration in patients undergoing mechanical power >17 J/min compared to <17 J/min?

Patients will be divided into two groups based on respiratory mechanics measurements: low MP group (average MP <17 J/min) and high MP group (average MP ≥17 J/min). The researchers will collect blood and BAL samples and perform cytokine assays.

Inclusion Criteria:

• Patients with AHRF (P/F <300 mmHg) undergoing invasive mechanical ventilation within 7 days from the onset of symptoms
• Invasive mechanical ventilation for less than 6 hours
• Evidence of newly developed lung consolidation on chest imaging (X-ray, CT)
• Age ≥18 years

Exclusion Criteria:

• Prior invasive mechanical ventilation during the same hospitalization
• Tracheostomy
• Severe anemia (Hb<7g/dL)
• Severe neutropenia
• Renal insufficiency or RRT (Renal Replacement Therapy)
• Noradrenaline >0.5 mcg/kg/min
• Pregnancy
• Extracorporeal circulation (ECCO2R, ECMO)
• Life expectancy <24 hours as clinically judged
• Lack of consent

Patients with AHRF undergoing mechanical ventilation