Additional work of breathing from trigger errors in mechanically ventilated children

Background Patient–ventilator asynchrony is associated with increased morbidity and mortality. A direct causative relationship between Patient–ventilator asynchrony and adverse clinical outcome have yet to be demonstrated. It is hypothesized that during trigger errors excessive pleural pressure swings are generated, contributing to increased work-of-breathing and self-inflicted lung injury. The objective of this study was to determine the additional work-of-breathing and pleural pressure swings caused by trigger errors in mechanically ventilated children. Methods Prospective observational study in a tertiary paediatric intensive care unit in an university hospital. Patients ventilated > 24 h and < 18 years old were studied. Patients underwent a 5-min recording of the ventilator flow–time, pressure–time and oesophageal pressure–time scalar. Pressure–time–product calculations were made as a proxy for work-of-breathing. Oesophageal pressure swings, as a surrogate for pleural pressure swings, during trigger errors were determined. Results Nine-hundred-and-fifty-nine trigger errors in 28 patients were identified. The additional work-of-breathing caused by trigger errors showed great variability among patients. The more asynchronous breaths were present the higher the work-of-breathing of these breaths. A higher spontaneous breath rate led to a lower amount of trigger errors. Patient–ventilator asynchrony was not associated with prolonged duration of mechanical ventilation or paediatric intensive care stay. Conclusions The additional work-of-breathing caused by trigger errors in ventilated children can take up to 30–40% of the total work-of-breathing. Trigger errors were less common in patients breathing spontaneously and those able to generate higher pressure–time–product and pressure swings. Trial registration Not applicable.

Oesophageal pressure-guided management of severe acute respiratory distress syndrome in a patient with intractable intracranial hypertension

We present a case of a young boy who sustained a traumatic brain injury (TBI) complicated by intractable intracranial hypertension and severe acute respiratory distress syndrome (ARDS) with hypercapnia. The coexisting pulmonary pathology significantly impacted intracranial pressure management. Oesophageal pressure manometry was used to guide ventilator and airway pressure management, allowing the team to optimise ARDS care while mitigating the risk of elevated intracranial pressure. While the literature describing the use of oesophageal pressure-guided ARDS management continues to evolve, there are no reported cases demonstrating use in patients with ARDS and intractable intracranial hypertension due to TBI.

Respiratory monitoring

This chapter discusses respiratory monitoring and includes discussion on pulmonary function tests in critical illness (including discussion on monitoring mechanical ventilation, monitoring the weaning process, and a summary), end-tidal CO2 monitoring (capnography, capnometry, measurement techniques, volumetric capnography, clinical applications of capnography, the shape of the volumetric capnogram), pulse oximetry (clinical applications, limitations, physical risks, recent advances), and monitoring transpulmonary pressure (physiological background, oesophageal pressure as a surrogate of pleural pressure, oesophageal pressure measurement, elastance-derived measurement, direct measurement, clinical use of oesophageal pressure, oesophageal pressure to guide therapy in acute respiratory distress syndrome, transpulmonary pressure to study the effects of spontaneous breathing during assisted ventilation, patient–ventilator asynchrony).