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Phenotypes based on respiratory drive and effort to identify the risk factors when P0.1 fails to estimate ∆PES in
Meryl Vedrenne-Cloquet1,2, Y Ito3, J Hotz3
1Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, USA. meryl_vedrenne@yahoo.fr.
Insights
Airway occlusion pressure (P0.1) often underestimates respiratory effort in pediatric acute respiratory distress syndrome (PARDS) patients, especially with high airway resistance, tidal volume, or opioid use. Further research is needed to understand the clinical impact of this mismatch.
Area of Science:
- Critical care medicine
- Pediatric respiratory physiology
- Mechanical ventilation
Background:
- Monitoring respiratory effort is crucial for lung and diaphragm protection during mechanical ventilation.
- Esophageal pressure (∆PES) is the gold standard but not routinely available.
- Airway occlusion pressure (P0.1) is a surrogate but has modest correlation with ∆PES in children.
Purpose of the Study:
- To identify risk factors for P0.1 over or underestimating ∆PES in ventilated children.
- To analyze phenotypes of respiratory effort and drive mismatch in pediatric acute respiratory distress syndrome (PARDS).
Main Methods:
- Secondary analysis of data from a randomized controlled trial in PARDS patients (NCT03266016).
- Measured ∆PES (∆PES-REAL) and predicted ∆PES (∆PES-PRED = 5.91*P0.1) daily.
- Used logistic regression to identify factors associated with mismatch phenotypes.
Main Results:
- In 953 patient days, ∆PES-REAL and ∆PES-PRED aligned in 77% of active days.
- High underestimated effort (12%) was linked to higher airway resistance, tidal volume, and opioid use, and lower ventilator rate.
- Overestimated effort (4%) was associated with higher alveolar dead space and lower respiratory resistance.
Conclusions:
- P0.1 frequently underestimates high respiratory effort in PARDS, particularly with high airway resistance, tidal volume, and opioid use.
- Further studies are needed to evaluate the clinical outcomes associated with these effort/drive mismatch phenotypes.
Background:
Monitoring respiratory effort and drive during mechanical ventilation is needed to deliver lung and diaphragm protection. Esophageal pressure (∆PES) is the gold standard measure of respiratory effort but is not routinely available. Airway occlusion pressure in the first 100 ms of the breath (P0.1) is a readily available surrogate for both respiratory effort and drive but is only modestly correlated with ∆PES in children. We sought to identify risk factors for P0.1 over or underestimating ∆PES in ventilated children.
Methods:
Secondary analysis of physiological data from children and young adults enrolled in a randomized controlled trial testing lung and diaphragm protective ventilation in pediatric acute respiratory distress syndrome (PARDS) (NCT03266016). ∆PES (∆PES-REAL), P0.1 and predicted ∆PES (∆PES-PRED = 5.91*P0.1) were measured daily to identify phenotypes based upon the level of respiratory effort and drive: one passive (no spontaneous breathing), three where ∆PES-REAL and ∆PES-PRED were aligned (low, normal, and high effort and drive), two where ∆PES-REAL and ∆PES-PRED were mismatched (high underestimated effort, and overestimated effort). Logistic regression models were used to identify factors associated with each mismatch phenotype (High underestimated effort, or overestimated effort) as compared to all other spontaneous breathing phenotypes.
Results:
We analyzed 953 patient days (222 patients). ∆PES-REAL and ∆PES-PRED were aligned in 536 (77%) of the active patient days. High underestimated effort (n = 119 (12%)) was associated with higher airway resistance (adjusted OR 5.62 (95%CI 2.58, 12.26) per log unit increase, p < 0.001), higher tidal volume (adjusted OR 1.53 (95%CI 1.04, 2.24) per cubic unit increase, p = 0.03), higher opioid use (adjusted OR 2.4 (95%CI 1.12, 5.13, p = 0.024), and lower set ventilator rate (adjusted OR 0.96 (95%CI 0.93, 0.99), p = 0.005). Overestimated effort was rare (n = 37 (4%)) and associated with higher alveolar dead space (adjusted OR 1.05 (95%CI 1.01, 1.09), p = 0.007) and lower respiratory resistance (adjusted OR 0.32 (95%CI 0.13, 0.81), p = 0.017).
Conclusions:
In patients with PARDS, P0.1 commonly underestimated high respiratory effort particularly with high airway resistance, high tidal volume, and high doses of opioids. Future studies are needed to investigate the impact of measures of respiratory effort, drive, and the presence of a mismatch phenotype on clinical outcome.
Trial Registration:
NCT03266016; August 23, 2017.
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