Title : Lung-protective ventilation compliance in mechanically ventilated ICU patients at a tertiary Care Hospital : A single-centre clinical audit
Abstract:
Background: Lung-protective ventilation (LPV) reduces ventilator-induced lung injury through limitation of tidal volume and airway pressures. Although LPV is well established in acute respiratory distress syndrome (ARDS), its principles are increasingly applied to mechanically ventilated critically ill patients more broadly. This audit assessed adherence to LPV principles in a UK intensive care unit and identified areas for improvement, including potential exposure to injurious tidal volumes during spontaneous ventilation.
Methods: A retrospective single-centre audit was conducted in the Critical Care Unit at Aberdeen Royal Infirmary, NHS Grampian. All adults receiving invasive mechanical ventilation between 1 and 31 August 2025 were included. Hourly ventilator data were extracted from the electronic ICU clinical information system (ICCA) for 48 patients. Prespecified LPV criteria included tidal volume ≤8 mL/kg ideal body weight (IBW) in non-ARDS patients, plateau pressure ≤30 cmH?O, and driving pressure (plateau pressure minus PEEP) ≤15 cmH?O. Sustained deviation was defined as more than 20% of ventilator-hours above the relevant threshold. Two or more consecutive hours with tidal volume >12 mL/kg IBW were considered a potentially injurious excursion. Spontaneously breathing periods were analysed separately for high tidal-volume exposure and potential patient self-inflicted lung injury (P-SILI).
Results: Twelve of 48 patients (25.0%) demonstrated clinically significant deviation from the predefined LPV parameters. The commonest abnormality was elevated driving pressure, with 7 patients (14.6%) spending more than 20% of controlled ventilation time with driving pressure >15 cmH?O. One patient (2.08%) had plateau pressure >30 cmH?O for more than 20% of controlled ventilation time, and one experienced consecutive tidal volumes >12 mL/kg IBW. IBW was not documented in one patient. During spontaneous ventilation, two patients (4.16%) spent more than 20% of ventilated time with tidal volumes >8 mL/kg IBW, and one patient (2.08%) met the exploratory criterion for increased P-SILI risk. Categories were mutually exclusive. No patients with a documented diagnosis of ARDS were identified.
Conclusion: Overall adherence to tidal-volume and plateau-pressure targets was good, while elevated driving pressure represented the principal opportunity for improvement. The audit highlighted the value of routine IBW documentation, regular plateau-pressure assessment, recognition of elevated driving pressure, and closer evaluation of excessive tidal volumes during assisted spontaneous ventilation. Targeted staff education and ventilator monitoring were recommended to strengthen lung-protective practice and reduce potentially avoidable ventilator-induced lung injury.
