Diaphragm Ultrasography to Predict Respiratory Failure in Infants with
Objetive: To evaluate the ultrasonographic contractile activity indices
of the diaphragm in infants with moderate and severe bronchiolitis
supported with high-flow nasal cannula (HFNC) or non-invasive
ventilation (NIV) to predict the need of invasive mechanical ventilation
(IMV). Methods: Prospective observational study in infants admitted to a
Pediatric Intensive Care Unit (PICU). Diaphragmatic excursion (dEx),
diaphragmatic inspiratory (dTi) and expiratory time (dTe), and fraction
of diaphragmatic thickening (dTF) were recorded at admission, 24 h and
48 h in both diaphragms. RESULTS: Twenty-six patiens were included (14
on HFNC and 12 on NIV) with a total of 56 ultrasonographic evaluations.
Three patients required IMV. Sixty-four percent of the patients on HFNC
required NIV as rescue therapy and 2/14 IMV (14,2%). In the HFNC group
there were no differences in dEx between those who required escalation
to NIV or IMV and those who didn’t. Diaphragmatic left thickening
fraction (Left dTF) increased in patients on HFNC requiring IMV vs those
needing NIV (Left dTF 47% vs 22% (13-30); p=0,046, r=0,7) (Fig 2).
Diaphragmatic inspiratory time was higher in infants on HFNC requiring
IMV and diaphragmatic expiratory time was shorter (dLET, p=0,038; dRET,
p=0,022). In the NIV group there were no diffenreces in dEx, dTi, dTe or
dTF between patients needing escalation to IMV and those who didn’t. We
found no correlation between a clinical score and echographic dTF.
CONCLUSION: In infants with moderate or severe brochiolitis receiving
HFNC the use of ultrasonographic left dTF could help predict respiratory
failure (RF) and need for IMV. The use of ultrasonographic diaphragmatic
excursion is of little help to predict both.