Cardiothoracic & vascular anesthesia
Magnitude and pattern of breathing effort during spontaneous breathing trials after cardiac surgery: a physiological model of sustained breathing effort despite diaphragm dysfunction
Authors' conclusion
Stable patients after cardiac surgery show an increase in respiratory drive and inspiratory effort with increasing load despite signs consistent with diaphragm dysfunction. Expiratory muscle use is common, it is associated with decreased diaphragm activity, higher intraoperative dose of opioids and decreases after extubation.
Study context
- Population
- Patients after cardiac surgery undergoing SBT
- Participants
- 30 patients
- Exposure
- PS5PEEP5 vs CPAP0 vs T-piece SBT
- Outcome
- Magnitude and pattern of breathing effort (pressure-time product per minute)
Methodological detailsrandomised order crossover of 3 SBT modalities
- Randomised order crossover of 3 SBT modalities
Main finding
As reported in the abstract
Pressure-time product per minute
P < 0.001
- Estimated mean global inspiratory effort during un-assisted modalities
- 138.5 (120.6,156.3) cmH2O•sec/min
Observational data: associations, not effects.
Further findings
Transdiaphragmatic pressure — PS5PEEP5 vs CPAP0, T-piece
P < 0.001
Maximum inspiratory pressure (Mueller maneuver)
- Maximum inspiratory pressure
- - 29.8 ± −12.6 cmH2O
Expiratory muscle effort (gastric pressure rise)
- Contribution to esophageal pressure drop during inspiration under mechanical ventilation
- 31-37%
- Association with higher intraoperative opioid dose
- P = 0.004
- Inverse association with respiratory muscle function
- P = 0.001
- Lower after extubation
Tension-time indices
- Within the higher end of a non-fatiguing range
Safety
Extubation
- All patients successfully extubated
Original publication
Magnitude and pattern of breathing effort during spontaneous breathing trials after cardiac surgery: a physiological model of sustained breathing effort despite diaphragm dysfunction. Crit Care. Published 25 April 2026. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →