Evolution of inspiratory muscle function in children during mechanical ventilation

Benjamin Crulli,Karen Harrington,Guillaume Emeriaud,Basil J Petrof,Jean-Paul Praud,Atsushi Kawaguchi

doi:10.1186/s13054-021-03647-w

Abstract

BackgroundThere is no universally accepted method to assess the pressure-generating capacity of inspiratory muscles in children on mechanical ventilation (MV), and no study describing its evolution over time in this population.MethodsIn this prospective observational study, we have assessed the function of the inspiratory muscles in children on various modes of MV. During brief airway occlusion maneuvers, we simultaneously recorded airway pressure depression at the endotracheal tube (ΔPaw, force generation) and electrical activity of the diaphragm (EAdi, central respiratory drive) over five consecutive inspiratory efforts. The neuro-mechanical efficiency ratio (NME, ΔPaw/EAdimax) was also computed. The evolution over time of these indices in a group of children in the pediatric intensive care unit (PICU) was primarily described. As a secondary objective, we compared these values to those measured in a group of children in the operating room (OR).ResultsIn the PICU group, although median NMEoccl decreased over time during MV (regression coefficient − 0.016, p = 0.03), maximum ΔPawmax remained unchanged (regression coefficient 0.109, p = 0.50). Median NMEoccl at the first measurement in the PICU group (after 21 h of MV) was significantly lower than at the only measurement in the OR group (1.8 cmH2O/µV, Q1–Q3 1.3–2.4 vs. 3.7 cmH2O/µV, Q1–Q3 3.5–4.2; p = 0.015). Maximum ΔPawmax in the PICU group was, however, not significantly different from the OR group (35.1 cmH2O, Q1–Q3 21–58 vs. 31.3 cmH2O, Q1–Q3 28.5–35.5; p = 0.982).ConclusionsThe function of inspiratory muscles can be monitored at the bedside of children on MV using brief airway occlusions. Inspiratory muscle efficiency was significantly lower in critically ill children than in children undergoing elective surgery, and it decreased over time during MV in critically ill children. This suggests that both critical illness and MV may have an impact on inspiratory muscle efficiency.

Highlights

There is no universally accepted method to assess the pressure-generating capacity of inspiratory mus‐ cles in children on mechanical ventilation (MV), and no study describing its evolution over time in this population
VIDD is highly prevalent in adult critical care (63–84% of patients depending on the phase of critical illness) [10, 20,21,22,23] and is associated with worse outcomes such as ventilation weaning failure [20, 21, 24, 25], longer duration of MV [8, 23, 24, 26, 27], prolonged Intensive care unit (ICU) admission [27], and increased mortality [21, 23, 26, 28]
Patients were on invasive ventilation for 63.9 h (Q1–Q3 50.4–77.4) and stayed in the pediatric intensive care unit (PICU) for 5.3 days (Q1–Q3 4–8.8)

Summary

Introduction

There is no universally accepted method to assess the pressure-generating capacity of inspiratory mus‐ cles in children on mechanical ventilation (MV), and no study describing its evolution over time in this population. Ill children frequently require support with mechanical ventilation (MV) which allows for an improvement in gas exchange and a decrease in work of breathing It is, imperative to limit its Crulli et al Crit Care (2021) 25:229 adversely affected by critical illness and therapies (ICUacquired diaphragm dysfunction, ICU–DD) [2], and by MV itself (ventilator-induced diaphragm dysfunction, VIDD) [3]. Diaphragm injury can result from insufficient respiratory effort secondary to over-assistance by MV [4], from excessive inspiratory effort due to under-assistance leading to fatigue [5], or from contractile activation, while the muscle is lengthening (e.g., during asynchrony or hyperinflation) [6] Studies in both animal models and humans have shown that MV is associated with a series of molecular changes in the diaphragm muscle [7]. VIDD is highly prevalent in adult critical care (63–84% of patients depending on the phase of critical illness) [10, 20,21,22,23] and is associated with worse outcomes such as ventilation weaning failure [20, 21, 24, 25], longer duration of MV [8, 23, 24, 26, 27], prolonged ICU admission [27], and increased mortality [21, 23, 26, 28]

Methods

Results

Discussion

Conclusion