Driving Pressure Optimization, RV-PA Coupling, and AKI in Mechanically Ventilated Critically Ill Patients

The tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) ratio is a validated, non-invasive bedside surrogate for RV-PA coupling, shown to correlate closely with invasively measured pressure-volume loop indices of RV-arterial coupling and to carry independent prognostic value in heart failure and pulmonary hypertension populations. More recently, TAPSE-based coupling indices have also demonstrated prognostic relevance in general critically ill populations, supporting their applicability outside the setting of chronic cardiopulmonary disease.

Separately, driving pressure (the difference between plateau pressure and PEEP) has emerged as a key determinant of ventilator-induced lung injury and mortality in ARDS, independent of tidal volume or PEEP in isolation, building on earlier evidence that lower tidal volume ventilation strategies improve outcomes in acute lung injury and ARDS.

This study will investigate whether a simple standardized lung-protective ventilation strategy aimed at optimizing ventilator driving pressure can improve RV-PA coupling, assessed by TAPSE/PASP ratio, and reduce AKI progression in mechanically ventilated critically ill patients.

Inclusion criteria

• Age ≥18 years.
• ICU admission.
• Invasive mechanical ventilation expected to continue for ≥48 hours.
• Adequate transthoracic echocardiographic acoustic window for assessment of TAPSE/PASP.

Exclusion criteria

• Pre-existing end-stage renal disease on chronic dialysis.
• Severe pulmonic or tricuspid valve disease precluding reliable TAPSE/PASP assessment.
• Pre-existing RV dysfunction of a non-pulmonary cause.
• Pregnancy.
• Patients expected to die within 24 hours.
• Technically inadequate echocardiographic window.
• Clinical contraindication to the proposed ventilation strategy.