Feasibility and safety of ultra-low tidal volume ventilation without extracorporeal circulation in moderately severe and severe ARDS patients

Abstract

Purpose: Mechanical ventilation with ultra-low tidal volume (VT) during ARDS may reduce alveolar strain, driving pressure and hence ventilator-induced lung injury, with the main drawback of worsening respiratory acidosis. We hypothesized that VT could be reduced down to 4 ml/kg, with clinically significant decrease in driving pressure, without the need for extracorporeal CO 2 removal, while maintaining pH > 7.20. Methods: We conducted a non-experimental before-and-after multicenter study on 35 ARDS patients with PaO 2 / FiO 2 ≤ 150 mmHg, within 24 h of ARDS diagnosis. After inclusion, VT was reduced to 4 ml/kg and further adjusted to maintain pH ≥ 7.20, respiratory rate was increased up to 40 min −1 and PEEP was set using a PEEP-FiO 2 table. The primary judgment criterion was driving pressure on day 2 of the study, as compared to inclusion. Results: From inclusion to day 2, driving pressure decreased significantly from 12 [9-15] to 8 [6-11] cmH 2 O, while VT decreased from 6.0 [5.9-6.1] to 4.1 [4.0-4.7] ml/kg. On day 2, VT was below 4.2 ml/kg in 65% [CI 95% 48%-79%], and below 5.25 ml/kg in 88% [CI 95% 74%-95%] of the patients. 2 patients (6%) developed acute cor pulmonale after inclusion. Eleven patients (32%) developed transient severe acidosis with pH < 7.15. Fourteen patients (41%) died before day 90. Conclusion: Ultra-low tidal volume ventilation may be applied in approximately 2/3 of moderately severe-to-severe ARDS patients, with a 4 cmH 2 O median reduction in driving pressure, at the price of transient episodes of severe acidosis in approximately 1/3 of the patients.

Extracorporeal life support for adults with acute respiratory distress syndrome

“…More work is needed to decrease the burden of ECMO-induced coagulopathy and associated bleeding, which is particularly important for ECCO 2 R. This includes work on improved biocompatible materials to reduce hemorrhagic or thrombotic adverse events; on pump technology to minimize shear stress, and hemolysis especially at low flows [ 76 ]. Beyond safety, the degree of benefit of ultra-protective ventilation remains to be proven [ 77 ] and large clinical trials to investigate the impact of ECCO 2 R for ARDS on outcomes are urgently needed (Table 2 ). Moreover, future research should focus on the selection of patients who will most likely benefit from the use of extracorporeal support [ 52 , 78 ].…”

Protective ventilation from ICU to operating room: state of art and new horizons

“…The application of ultralow V T ventilation in patients with severe ARDS requires a neuromuscular block and deep sedation to prevent asynchrony and P-SILI; this strategy can also be used during extracorporeal membrane oxygenation to allow the lungs to rest as well as to prevent them from de-aeration and collapse. The recent study of Richard et al [45] demonstrated that ultraprotective V T could be safely set in almost two-third of patients with severe ARDS, which resulted in a mean decrease of 4 cmH 2 O in the P DRIVE , but it was accompanied by transient respiratory acidosis in one-third of patients. Therefore, permissive hypercapnia should be limited to the range of 60-70 mmHg to avoid severe acidosis.…”

Zukunft der Intensivmedizin – Künstliche Intelligenz

“…den Einsatz von Tidalvolumina ≤ 6 ml pro kg idealisiertem Körpergewicht eine starke Empfehlung ausgesprochen, die auf einer vorhandenen Evidenz mit moderater Qualität basiert [17]. Allerdings zeigen einige Untersuchungen, dass je nach Schwere der Erkrankung und je nach Anteil atelektatischer Lungenareale noch kleinere Tidalvolumina sinnvoll sein können, um beatmungsassoziierte Schädigungen zu begrenzen [18,19].…”