Use of Transpulmonary Pressure Monitoring in the Management of Extrapulmonary Pediatric Acute Respiratory Distress Syndrome With multi organ dysfunction syndrome (MODS): Are We Peepophobic?

Transpulmonary Pressure-Guided Mechanical Ventilation in Severe Acute Respiratory Distress Syndrome in PICU: Single-Center Retrospective Study in North India, 2018-2021

OBJECTIVES

In this study, we have reviewed the association between esophageal pressure-guided positive end-expiratory pressure (PEEP) setting and oxygenation and lung mechanics with a conventional mechanical ventilation (MV) strategy in patient with moderate to severe pediatric acute respiratory distress syndrome (PARDS).

DESIGN

Retrospective cohort, 2018-2021.

SETTING

Tertiary PICU.

PATIENTS

Moderate to severe PARDS patients who required MV with PEEP of greater than or equal to 8 cm H2O.

INTERVENTIONS

Esophageal pressure (i.e., transpulmonary pressure [PTP]) guided MV vs. not.

MEASUREMENTS AND MAIN RESULTS

We identified 26 PARDS cases who were divided into those who had been managed with PTP-guided MV (PTP group) and those managed with conventional ventilation strategy (non-PTP). Oxygenation and lung mechanics were compared between groups at baseline (0 hr) and 24, 48, and 72 hours of MV. There were 13 patients in each group in the first 24 hours. At 48 and 72 hours, there were 11 in PTP group and 12 in non-PTP group. On comparing these groups, first, use of PTP monitoring was associated with higher median (interquartile range) mean airway pressure at 24 hours (18 hr [18-20 hr] vs. 15 hr [13-18 hr]; p = 0.01) and 48 hours (19 hr [17-19 hr] vs. 15 hr [13-17 hr]; p = 0.01). Second, use of PTP was associated with higher PEEP at 24, 48, and 72 hours (all p < 0.05). Third, use of PTP was associated with lower Fio2 and greater Pao2 to Fio2 ratio at 72 hours. Last, there were 18 of 26 survivors, and we failed to identify an association between use of PTP monitoring and survival.

CONCLUSIONS

In this cohort of moderate to severe PARDS cases undergoing MV with PEEP greater than or equal to 8 cm H2O, we have identified some favorable associations of oxygenation status when PTP-guided MV was used vs. not. Larger studies are required.

Pleural and transpulmonary pressures to tailor protective ventilation in children

This review aims to: (1) describe the rationale of pleural (P_PL) and transpulmonary (P_L) pressure measurements in children during mechanical ventilation (MV); (2) discuss its usefulness and limitations as a guide for protective MV; (3) propose future directions for paediatric research. We conducted a scoping review on P_L in critically ill children using PubMed and Embase search engines. We included peer-reviewed studies using oesophageal (P_ES) and P_L measurements in the paediatric intensive care unit (PICU) published until September 2021, and excluded studies in neonates and patients treated with non-invasive ventilation. P_L corresponds to the difference between airway pressure and P_PL Oesophageal manometry allows measurement of P_ES, a good surrogate of P_PL, to estimate P_L directly at the bedside. Lung stress is the P_L, while strain corresponds to the lung deformation induced by the changing volume during insufflation. Lung stress and strain are the main determinants of MV-related injuries with P_L and P_PL being key components. P_L-targeted therapies allow tailoring of MV: (1) Positive end-expiratory pressure (PEEP) titration based on end-expiratory P_L (direct measurement) may be used to avoid lung collapse in the lung surrounding the oesophagus. The clinical benefit of such strategy has not been demonstrated yet. This approach should consider the degree of recruitable lung, and may be limited to patients in which PEEP is set to achieve an end-expiratory P_L value close to zero; (2) Protective ventilation based on end-inspiratory P_L (derived from the ratio of lung and respiratory system elastances), might be used to limit overdistention and volutrauma by targeting lung stress values < 20-25 cmH₂O; (3) P_PL may be set to target a physiological respiratory effort in order to avoid both self-induced lung injury and ventilator-induced diaphragm dysfunction; (4) P_PL or P_L measurements may contribute to a better understanding of cardiopulmonary interactions. The growing cardiorespiratory system makes children theoretically more susceptible to atelectrauma, myotrauma and right ventricle failure. In children with acute respiratory distress, P_PL and P_L measurements may help to characterise how changes in PEEP affect P_PL and potentially haemodynamics. In the PICU, P_PL measurement to estimate respiratory effort is useful during weaning and ventilator liberation. Finally, the use of P_PL tracings may improve the detection of patient ventilator asynchronies, which are frequent in children. Despite these numerous theoritcal benefits in children, P_ES measurement is rarely performed in routine paediatric practice. While the lack of robust clincal data partially explains this observation, important limitations of the existing methods to estimate P_PL in children, such as their invasiveness and technical limitations, associated with the lack of reference values for lung and chest wall elastances may also play a role. P_PL and P_L monitoring have numerous potential clinical applications in the PICU to tailor protective MV, but its usefulness is counterbalanced by technical limitations. Paediatric evidence seems currently too weak to consider oesophageal manometry as a routine respiratory monitoring. The development and validation of a noninvasive estimation of P_L and multimodal respiratory monitoring may be worth to be evaluated in the future.

Use of esophageal balloon manometry in the management of pediatric acute respiratory distress syndrome

There is paucity of literature regarding the use of esophageal balloon manometry in the management of Pediatric Acute Respiratory Distress Syndrome. We describe our first ever experience of successful usage of esophageal balloon pressure manometry in a child with acute respiratory distress syndrome. This is a six-year-old girl who presented with shortness of breath and fever and was found to be in severe acute respiratory distress syndrome due to septic shock secondary to group A streptococcus. The patient was managed using an esophageal balloon manometry for positive end-expiratory pressure titration. She was liberated from invasive mechanical ventilation on day 7 of hospital course. Esophageal balloon manometry guided positive end-expiratory pressure for 103 out of 155 hours of ventilation with no obvious sequelae. Our case shows the feasibility of transpulmonary pressure measurements in pediatric patients. This practice may be useful to optimize management in pediatric acute respiratory distress syndrome to improve outcomes.