Association of respiratory drive and effort with mortalityand time to discharge in patients on mechanical ventilation in Canada: a longitudinal, prospective, registry-based cohort study

September 29, 2025 Leave a comment

Study Reference

Dianti J, Lovblom LE, Iftikhar MA, et al. Association of respiratory drive and effort with mortality and time to discharge in patients on mechanical ventilation in Canada: a longitudinal, prospective, registry-based cohort study. Lancet Respir Med [Internet] 2025 [cited 2025 Sept 22];0(0). Available from: https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(25)00297-8/abstract

Brief Summary for Clinicians

What This Study Found

This large study from Toronto General Hospital followed 1,186 mechanically ventilated patients and measured their respiratory drive and effort daily using simple bedside tests you’re already familiar with:

  • P₀.₁ (airway occlusion pressure) – measures respiratory drive
  • Pocc (expiratory occlusion pressure) – measures respiratory effort
  • Dynamic driving pressure – pressure delivered by the ventilator

Key Findings

The “Goldilocks Zone”: The data suggested patients had better outcomes with respiratory drive and effort that was “just right” – not too little, not too much:

  • Optimal P₀.₁ range: 2-5 cm H₂O
  • Optimal Pocc range: -10 to -20 cm H₂O

When oxygenation was poor (PaO₂:FiO₂ ≤150): Both very low AND very high respiratory effort were associated with:

  • Higher ICU mortality
  • Longer ICU stays

Patient-ventilator interaction: High patient effort appeared to magnify the harmful effects of high ventilator driving pressures on outcomes.

Clinical Implications

  1. These measurements you take daily may have prognostic value – the data suggests they could provide meaningful information beyond routine documentation
  2. Pay special attention when patients have severe hypoxemia – that’s when respiratory effort levels appeared to matter most for outcomes
  3. Consider the combined picture: The study suggests both the pressure from the ventilator AND the patient’s own breathing effort may interact to affect lung injury risk
  4. This observational data supports monitoring these parameters as they may help inform sedation and ventilator management decisions

Important limitation: This was an observational study, not a randomized controlled trial, so causation cannot be definitively established. However, the findings suggest that the respiratory mechanics measurements you perform daily may provide valuable information about patient risk and recovery potential that could be worth considering in clinical decision-making.

Reference

Dianti J, Lovblom LE, Iftikhar MA, et al. Association of respiratory drive and effort with mortality and time to discharge in patients on mechanical ventilation in Canada: a longitudinal, prospective, registry-based cohort study. Lancet Respir Med [Internet] 2025 [cited 2025 Sept 22];0(0). Available from: https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(25)00297-8/abstract

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