ETS+LR, endotracheal suctioning followed by a lung recruitment manoeuvre; ETS-LR, endotracheal suctioning without a following lung recruitment manoeuvre; FiO2, fractional inspired oxygen; set PEEP; set positive end-expiratory pressure; Intrinsic PEEP, PEEP above set PEEP after an expiratory hold; Vt, tidal volume.
PEEP adjustment by esophageal pressure was close to empirically set PEEP and can improve oxygenation.
Also, this method does not directly set PEEP but rather uses a short expiratory duration to generate intrinsic PEEP, which is used as a tool to stabilize the lung.
One strategy that may lead to a PEEP setting that maintains lung recruitment without excessive overdistension is to set PEEP 2 cmH2O above the lower inflection point of a static or quasi-static ("low-flow") pressure-volume loop [ 7].
They demonstrated that EIT-guided ventilation resulted in a higher PEEP, improved global and regional compliance, improved oxygenation, and reduced lung histopathology as compared with ARDSnet protocol set PEEP.
The PEEP level was set to achieve the minimal static elastance of the respiratory system, compared with strategies that set PEEP based on oxygenation criteria [ 12- 14], or a PEEP/FiO2 combination table [ 15].
Furthermore, several animal mechanistic and efficacy models have compared time-controlled PEEP to set PEEP.
Although using VCap or V D/Vt to set PEEP has not been tested for efficacy in a clinical trial, it is a potentially useful tool to set PEEP at the bedside.
Fig. 3 Methods used to set PEEP using a combined recruitment maneuver, and PEEP titration to a PO2 + PCO2 ≥ 400.
Dashed line indicates the 10% drop which we used as a cutoff to set PEEP based on EIT.
In a ten-patient study comparing auto-PEEP to set PEEP, there was no difference in lung compliance with only slightly worse gas exchange with auto-PEEP [34].
