Variability of Tidal Volume in Patient-Triggered Mechanical
Ventilation in ARDS
Introduction
Actually, the volume volume control mode, this goal is easy to achieve when the
patient receives sedation and neuromuscular blockade.
However, once sedation and paralysis are withdrawn following
clinical improvement, spontaneous breathing.
Methods
Ventilator Settings
Our 6-mL/kg IBW VT target, regardless of sex, was 390 mL.
In the Lung Safe study, the set VT averaged 7.8, 7.6, and
7.5 mL/kg IBW (ie, 130, 127, and 125% of the 6-mL/kg
IBW in mild, moderate, and severe ARDS, respectively).
We applied this percentage point to both the total and set
f in the Lung Safe study to compute adjusted total and set
f in the present study to maintain an equivalent minute
ventilation.
Data Analysis
In case of interaction
between the covariates, we planned to perform a series of
non-parametric or parametric analyses of variance to test
the effect of ventilator mode on VT at each f and effort.
That means that we planned to perform Kruskal-Wallis
non-parametric or one-way analysis of variance, depending
on the distribution of VT. For each test, we planned
post hoc comparisons with PSV without guaranteed VT,
used as the control, by using the Dunn test or Dunnett test,
respectively.
Results
Across ModeS
The distribution of VT over all f, effort, and ARDS
categories significantly differed across modes
Across Modes According to f and Effort
The mixed-effects model found that modes, f, and effort
intensity were significantly associated with VT with a significant
interaction between them. Therefore, we split the
analysis into 4 subgroups determined by the combination
of f and effort intensity
Conclusions
Discussion
Our first hypothesis was that in PSV, the effort intensity-related
VT will result in greater VT than in other patient-triggered
modes because the synchronization between
effort and mechanical insufflation is maximal. Present data
confirmed this hypothesis, which reflects some clinical
experience.