PEEP-FiO2 table versus EIT to titrate PEEP in mechanically ventilated patients with COVID-19-related ARDS

Abstract

Rationale It is unknown how to titrate positive end-expiratory pressure (PEEP) in patients with COVID-19-related acute respiratory distress syndrome (ARDS). Guidelines recommend the one-size-fits-all PEEP-FiO2 table. In this retrospective cohort study, an electrical impedance tomography (EIT)-guided PEEP trial was used to titrate PEEP. Objectives To compare baseline PEEP according to the high PEEP-FiO2 table and personalized PEEP following an EIT-guided PEEP trial. Methods We performed an EIT-guided decremental PEEP trial in patients with moderate-to-severe COVID-19-related ARDS upon intensive care unit admission. PEEP was set at the lowest PEEP above the intersection of curves representing relative alveolar overdistention and collapse. Baseline PEEP was compared with PEEP set according to EIT. We identified patients in whom the EIT-guided PEEP trial resulted in a decrease or increase in PEEP of ≥ 2 cmH2O. Measurements and main results We performed a PEEP trial in 75 patients. In 23 (31%) patients, PEEP was decreased ≥ 2 cmH2O, and in 24 (32%) patients, PEEP was increased ≥ 2 cmH2O. Patients in whom PEEP was decreased had improved respiratory mechanics and more overdistention in the non-dependent lung region at higher PEEP levels. These patients also had a lower BMI, longer time between onset of symptoms and intubation, and higher incidence of pulmonary embolism. Oxygenation improved in patients in whom PEEP was increased. Conclusions An EIT-guided PEEP trial resulted in a relevant change in PEEP in 63% of patients. These results support the hypothesis that PEEP should be personalized in patients with ARDS.

Is COVID-19 different from other causes of acute respiratory distress syndrome?

“… [68] Numerous studies seeking to assess the optimal PEEP titration strategy in patients with COVID-19-associated ARDS were published. [69] , [70] , [71] However, there is no evidence that PEEP should be titrated differently in COVID-19 and non-COVID-19-associated ARDS. The previously described data reporting various and evolutive recruitability in patients with COVID-19-associated ARDS actually suggest that an individual assessment of the potential for lung recruitment in response to a high level of PEEP may be needed to optimize PEEP settings in these patients as in patients with “classical forms” of ARDS.…”

Setting positive end-expiratory pressure by using electrical impedance tomography

“…In a retrospective analysis of PEEP values set according to the overdistension/collapse crossover point it was shown that they differed by at least 2 cmH 2 O from the initially set values according to the high PEEP/F I O 2 table in almost two-thirds of the analyzed ARDS patients [21].…”

Higher PEEP in intubated COVID-19-associated ARDS patients? We are not sure

“…We have read with great interest the article published in Critical Care by Somhorst et al entitled «PEEP‑FiO 2 table versus EIT to titrate PEEP in mechanically ventilated patients with COVID‑19‑related ARDS» [ 1 ]. This retrospective observational study aimed to select the «optimum» positive end-expiratory pressure (PEEP) in mechanically ventilated patients with COVID-19-related acute respiratory distress syndrome (ARDS) by electrical impedance tomography (EIT), based on the balance between alveolar collapse and overdistension.…”

“…Second, let’s focus on the oxygenation status as a stratification tool for the selection of the appropriate respiratory support method in ARDS [ 8 ]. So, according to Table 1, PaO 2 /FiO 2 in the study by Somhorst et al was 162 [110–201] mmHg, and the FiO 2 level was around 50% [ 1 ]. We can speculate that at least a significant part of these patients could be oxygenated noninvasively—by NIV or high-flow oxygen therapy (HFOT).…”