Driving pressure is not predictive of ARDS outcome in chest trauma patients under mechanical ventilation

Acute respiratory distress syndrome (ARDS): from mechanistic insights to therapeutic strategies

Acute respiratory distress syndrome (ARDS) is a clinical syndrome of acute hypoxic respiratory failure caused by diffuse lung inflammation and edema. ARDS can be precipitated by intrapulmonary factors or extrapulmonary factors, which can lead to severe hypoxemia. Patients suffering from ARDS have high mortality rates, including a 28-day mortality rate of 34.8% and an overall in-hospital mortality rate of 40.0%. The pathophysiology of ARDS is complex and involves the activation and dysregulation of multiple overlapping and interacting pathways of systemic inflammation and coagulation, including the respiratory system, circulatory system, and immune system. In general, the treatment of inflammatory injuries is a coordinated process that involves the downregulation of proinflammatory pathways and the upregulation of anti-inflammatory pathways. Given the complexity of the underlying disease, treatment needs to be tailored to the problem. Hence, we discuss the pathogenesis and treatment methods of affected organs, including 2019 coronavirus disease (COVID-19)-related pneumonia, drowning, trauma, blood transfusion, severe acute pancreatitis, and sepsis. This review is intended to provide a new perspective concerning ARDS and offer novel insight into future therapeutic interventions.

Extracorporeal membrane oxygenation in trauma patient in France: A retrospective nationwide registry

BACKGROUND

Indications for Veno-venous (VV) or veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) after trauma rely on poor evidence. The main aims were to describe the population of trauma patients requiring either VV or VA ECMO and report their clinical management and outcomes.

METHODS

An observational multicentre retrospective study was conducted in 17 Level 1 trauma centres in France between January 2010 and December 2021. All patients admitted for major trauma were screened for inclusion, and those receiving either VV ECMO or VA ECMO were included. The primary outcome was in-hospital mortality.

RESULTS

Among the 52,851 patients screened, 179 were included, with 143 supported by VV ECMO (median [Q1-Q3] age 32 years [24-48]; men 83.5%; injury severity score [ISS] 33 [25-43] and 76 (53.6%) with a traumatic brain injury [TBI]) and 36 supported by VA ECMO (median age 39 years [25-55]; men 88.9%; ISS 36 [25-56] and 23 (63.9%) with a TBI). In the VV ECMO group, three indications for ECMO implementation were chest injuries (n = 68, 47.6%), ventilator-associated pneumonia (VAP; n = 57, 39.9%), and extra-respiratory acute respiratory distress syndrome (ARDS; n = 57, 39.9%). In the VV ECMO group, 45.8% (n = 65) died in the hospital, with 33 (48.5%) deaths following cannulation for chest injuries, 22 (39.3%) following cannulation for VAP, and 10 (55.6%) following cannulation for extrapulmonary ARDS. In the VA ECMO group, 75.0% (n = 27) died during their hospital stay.

CONCLUSIONS

In-hospital mortality of trauma patients requiring ECMO for refractory ARDS varied according to indications. The best prognosis was observed in the subgroup of pneumonia-induced ARDS patients.

Association between driving pressure, systemic inflammation and non-pulmonary organ dysfunction in patients with acute respiratory distress syndrome, a prospective pathophysiological study

BACKGROUND

Driving pressure is thought to determine the effect of low tidal ventilation on survival in patients with acute respiratory distress syndrome. The leading cause of mortality in these patients is non-pulmonary multiorgan dysfunction, which is believed to worsen due to the biological response to mechanical ventilation (biotrauma). Therefore, we aimed to analyze the association between driving pressure, biotrauma, and non-pulmonary multiorgan dysfunction. Additionally, we analyzed this relationship for tidal volume/predicted body weight.

METHODS

Observational study that included adult patients with acute respiratory distress syndrome undergoing invasive mechanical ventilation admitted to the Hospital Clinic of Barcelona, Spain, between June 2019 and February 2021. We conducted mixed-effects models to assess the effects of driving pressure and tidal volume/predicted body weight on the evolution of 22 log-transformed biomarker variables during the first, third, and fifth days after study enrollment. These 22 systemic biomarkers characterized epithelial and endothelial pulmonary dysfunction, inflammation, and coagulation disorders in the included patients. In the same fashion, the association between driving pressure and non-pulmonary multiorgan dysfunction was evaluated by the non-pulmonary sequential organ failure assessment score (non-pulmonary SOFA) and its associated variables. Finally, we performed mediation analyses to assess whether the relationship between biomarkers and driving pressure was mediated by other ventilator-induced lung injury parameters.

RESULTS

Thirty-eight patients were included. Driving pressure was independently associated with soluble Receptor for advanced glycation end-products, Interleukin (IL)-8, IL-6, IL-10, IL-17, Interferon-ɣ, Chemokine (C-C motif)-2, Vascular endothelial growth factor, Tissue factor, Protein C, Protein S, and higher dose of norepinephrine. However, this relationship attenuated over time. In contrast, tidal volume/predicted body weight was not associated with any of the 22 biomarkers tested . A concomitant increase in positive end-inspiratory plateau pressure or tidal volume did not mediate the effect of driving pressure on biomarkers. Conversely, the association between compliance of the respiratory system and pulmonary epithelial dysfunction was primarily mediated by driving pressure.

CONCLUSIONS

Driving pressure, but not tidal volume/predicted body weight, was correlated with epithelial and endothelial pulmonary dysfunction, inflammation, coagulation disorders, and hemodynamic dysfunction. However, this relationship diminished over time.

Predictive performance of the variation rate of the driving pressure on the outcome of invasive mechanical ventilation in patients with acute respiratory distress syndrome

PURPOSE

To assess the value of the driving pressure variation rate (ΔP%) in predicting the outcome of weaning from invasive mechanical ventilation in patients with acute respiratory distress syndrome.

METHODS

In this case-control study, a total of 35 patients with moderate-severe acute respiratory distress syndrome were admitted to the intensive care unit between January 2022 and December 2022 and received invasive mechanical ventilation for at least 48 h were enrolled. Patients were divided into successful weaning group and failed weaning group depending on whether they could be removed from ventilator support within 14 days. Outcome measures including driving pressure, PaO2:FiO2, and positive end-expiratory pressure, etc. were assessed every 24 h from day 0 to day 14 until successful weaning was achieved. The measurement data of non-normal distribution were presented as median (Q1, Q3), and the differences between groups were compared by Wilcoxon rank sum test. And categorical data use the Chi-square test or Fisher's exact test to compare. The predictive value of ΔP% in predicting the outcome of weaning from the ventilator was analyzed using receiver operating characteristic curves.

RESULTS

Of the total 35 patients included in the study, 17 were successful vs. 18 failed in weaning from a ventilator after 14 days of mechanical ventilation. The cut-off values of the median ΔP% measured by Operator 1 vs. Operator 2 in the first 4 days were ≥ 4.17% and 4.55%, respectively (p < 0.001), with the area under curve of 0.804 (sensitivity of 88.2%, specificity of 64.7%) and 0.770 (sensitivity of 88.2%, specificity of 64.7%), respectively. There was a significant difference in mechanical ventilation duration between the successful weaning group and the failure weaning group (8 (6, 13) vs. 12 (7.5, 17.3), p = 0.043). The incidence of ventilator-associated pneumonia in the successful weaning group was significantly lower than in the failed weaning group (0.2‰ vs. 2.3‰, p = 0.001). There was a significant difference noted between these 2 groups in the 28-day mortality (11.8% vs. 66.7%, p = 0.003).

CONCLUSION

The median ΔP% in the first 4 days of mechanical ventilation showed good predictive performance in predicting the outcome of weaning from mechanical ventilation within 14 days. Further study is needed to confirm this finding.

American Association for the Surgery of Trauma/American College of Surgeons Committee on Trauma clinical protocol for management of acute respiratory distress syndrome and severe hypoxemia

LEVEL OF EVIDENCE

Therapeutic/Care Management: Level V.