Pleural and transpulmonary pressures to tailor protective ventilation in children

Abstract

This review aims to: (1) describe the rationale of pleural (PPL) and transpulmonary (PL) 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 PL in critically ill children using PubMed and Embase search engines. We included peer-reviewed studies using oesophageal (PES) and PL measurements in the paediatric intensive care unit (PICU) published until September 2021, and excluded studies in neonates and patients treated with non-invasive ventilation. PL corresponds to the difference between airway pressure and PPL. Oesophageal manometry allows measurement of PES, a good surrogate of PPL, to estimate PL directly at the bedside. Lung stress is the PL, 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 PL and PPL being key components. PL-targeted therapies allow tailoring of MV: (1) Positive end-expiratory pressure (PEEP) titration based on end-expiratory PL (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 PL value close to zero; (2) Protective ventilation based on end-inspiratory PL (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) PPL may be set to target a physiological respiratory effort in order to avoid both self-induced lung injury and ventilator-induced diaphragm dysfunction; (4) PPL or PL 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, PPL and PL measurements may help to characterise how changes in PEEP affect PPL and potentially haemodynamics. In the PICU, PPL measurement to estimate respiratory effort is useful during weaning and ventilator liberation. Finally, the use of PPL tracings may improve the detection of patient ventilator asynchronies, which are frequent in children. Despite these numerous theoritcal benefits in children, PES 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 PPL 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. PPL and PL 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 PL and multimodal respiratory monitoring may be worth to be evaluated in the future.

Respiratory effort during noninvasive positive pressure ventilation and continuous positive airway pressure in severe acute viral bronchiolitis

“…Despite its technical limitation and invasiveness that limit its use in routine practice, esophageal manometry is to date the only technique which allows an accurate and continuous monitoring of respiratory effort. 16 By using esogastric pressures as a surrogate of respiratory effort to optimize CPAP and NIPPV in infants with bronchiolitis, we failed to show a superiority of physiological settings as compared to clinical settings. Several reasons can explain this finding.…”

“…Our data show the importance to tailor the noninvasive respiratory support in infants with bronchiolitis to optimize respiratory effort while avoiding the adverse effects of respiratory assistance. Despite its technical limitation and invasiveness that limit its use in routine practice, esophageal manometry is to date the only technique which allows an accurate and continuous monitoring of respiratory effort 16 . By using esogastric pressures as a surrogate of respiratory effort to optimize CPAP and NIPPV in infants with bronchiolitis, we failed to show a superiority of physiological settings as compared to clinical settings.…”

“…After the patient's inclusion, a 2.1-mm external diameter esogastric catheter mounted pressure transducer system with two integrated pressure transducers (Gaeltec Devices Ltd.), one for esophageal (P ES ) and one for gastric (P GAS ) pressures measurement, was inserted as recommended. 15,16 Transdiaphragmatic pressure (P DI ) was obtained by subtracting online the P ES signal from the P GAS signal. All the signals were recorded at 200 Hz using an analogical/numeric acquisition system (MP100; BIOPAC Systems) and a dedicated software (AcqKnowledge; BIOPAC Systems).…”

Successful application of airway pressure release ventilation in a child with severe acute respiratory distress syndrome induced by trauma: a case report

“…Although spontaneous breathing can bring a series of physiological benefits, patients are at risk of developing VILI when alterations occur in breathing mechanics and respiratory effort, which may lead to enhanced voluntary breathing, marked fluctuations in tidal volume and transpulmonary pressure. Transpulmonary pressure monitoring using oesophageal manometry may be helpful to understand the lung compliance, patient effort and to manage protective ventilation [ 22 ]. Despite the presence of bilateral hemopneumothorax, the therapeutic benefits of APRV manifested before any adverse effects.…”

Padrões hemodinâmicos pulmonares em pacientes pediátricos com defeitos septais cardíacos congênitos: relação com mediadores inflamatórios e a presença não suspeitada de vírus respiratórios

“…A pressão arterial pulmonar (PAP) sistólica, diastólica e média foi aferida de forma direta, antes e após a CEC, sendo a última medida aferida na vigência de oxido nítrico inalatório. Note-se que as medidas de PAP foram realizadas com estratégia de ventilação mecânica de rotina (120,121) ventilação mecânica foi utilizada estratégia protetora, com volume corrente de 6ml/kg de peso (122) , e óxido nítrico inalatório (NOi), na dose de 20 ppm, salvo em pacientes que necessitaram de ventilação prolongada por razões outras que não a HP. A intubação orotraqueal e ventilação mecânica foram mantidas por pelo menos 72 horas.…”