Article Notes
Why is this important?
Although we have moved beyond routinely using high tidal volumes in favour of ’protective ventilation strategies’ the specifics of what is protective and what improves outcomes is controversial. Previous trials have struggled to demonstrate post-operative respiratory benefits from protective strategies.
What did they do?
In this small randomised controlled trial, Généreux et al. investigated whether intraoperative PEEP (7 cmH2O) and recruitment manoeuvres (RM) q30min would reduce atelectasis post-extubation. Using ultrasound to measure intraoperative and post-operative atelectasis gives their study greater flexibility than other studies using CT scanning, generally considered the gold standard for atelectasis measurement.
And they found...
Among 34-85 yo women undergoing open gynae-oncology surgery >2h duration, there was no post-extubation difference in atelectasis whether receiving PEEP/RM or zero PEEP.
Not so fast
There was however less intraoperative atelectasis among the protective ventilation group, supporting the common use of PEEP and RM to improve oxygenation during surgery. Additionally, they specifically excluded morbidly obese women (BMI > 40 kg/m2), an increasingly common demographic at risk of ventilation challenges.
Nonetheless this study adds to the evidence that current protective ventilation strategies do not actually reduce post-operative respiratory complications.
Be smart
One interesting observation was the large amount of inter-patient variability, the researchers noting:
“...this heterogeneity highlights the need to dynamically monitor lung aeration changes and personalise our delivery of mechanical ventilation in the perioperative setting.”
As with many perioperative interventions, the benefits may in fact lie in the personalisation of our care for each individual patient.