Table 1

Summary of the rationale and clinical applications for P_L and P_PL monitoring in critically ill children undergoing invasive mechanical ventilation

Protective ventilation	Why? Paediatric specificities and potential consequences		What’s known? Actual evidence in critically ill children	What’s new? Potential applications and future studies
PEEP titration	Low FRC Lower diastolic function Higher right afterload	Lung collapse Right ventricle failure	Low PEEP is associated with mortality53 Cardiac index and BP are not changed55 when increasing PEEP in PARDS but BP decreases after recruitment manoeuvres during cardiac surgery59 No evidence about the benefits of a P_L-targeted PEEP titration	To assess the effect of a P_L-targeted PEEP titration on RV function PARDS Congenital heart defects
Target physiological respiratory effort	Patient-ventilator asynchrony Dynamic hyperinflation and diaphragm expiratory activation High RR, low lung volume Fatigable respiratory muscles	VIDD VILI ? P-SILI ?	Trigger errors induce additional respiratory effort65 Usefulness of P_PL swings analysis PEEP titration to limit dynamic hyperinflation and improve asynchrony66 Detect reverse triggering30	To investigate the deleterious effects of patient-ventilator asynchrony To assess if strenuous efforts leads to P-SILI in children To validate the usefulness of P_PL monitoring during active conditions as a guide for lung and diaphragmatic protective ventilation
Optimisation of weaning	Fatigable respiratory muscles Post-extubation upper airway obstruction	VIDD High risk of extubation failure	SBT is feasible without excessive respiratory effort26 62 A high postextubation respiratory effort predicts extubation failure26	To validate the usefulness of P_PL monitoring to detect potentially difficult-to-wean patients and guide long-term ventilatory management

References are added in brackets.
BP, blood pressure; FRC, functional respiratory capacity; PARDS, paediatric acute respiratory distress syndrome; PEEP, positive end-expiratory pressure; P_L, transpulmonary pressure; P_PL, pleural pressure; P-SILI, patient self-induced lung injury; RR, respiratory rate; RV, Right ventricle; SBT, spontaneous breathing trial; VIDD, ventilator-induced diaphragm injury; VILI, ventilator-induced lung injury.