RESULTS
Among the 824 infants consecutively hospitalized for bronchiolitis in
the Paediatric Emergency Department of “Sapienza” University of Rome,
130 (63.8% males; median age 56.5 days, range 14-319) underwent HFNC
and we registered a failure of HFNC in only 11 infants (8.5%) (Figure
1).
Concerning demographic and clinical characteristics, infants receiving
MV were significantly younger and had a lower body weight than infants
who underwent HFNC only. Clinical severity score just before starting
HFNC was higher in infants who needed MV. The percentage of patients who
underwent low flow oxygen therapy before HFNC were significantly higher
in infants who needed MV comparing to infants who were successfully
treated only with HFNC. Days of disease and clinical severity score at
hospital admission did not show statistically significant differences
between the two groups (Table 1).
Comparing laboratory and radiological findings, patients who needed MV
had a significantly lower lymphocytes count and mean platelet
volume/platelet count ratio (PLT/MPV) than infants who underwent HFNC
only (Table 2).
Complete lobar consolidation was found in 90.9% of infants who
underwent MV comparing to 14.9% of patients exclusively supported by
HFNC and the upper right lobe consolidation was more frequently detected
than the upper left lobe consolidation (Table 2). Analysing infants who
required MV, 9 out of 11 patients underwent at least two CXR before MV.
In particular, 8 (72.7%) infants had a gradual development up to a
complete upper lobe consolidation, and in one (9.1%) no consolidation
but severe air trapping and diffuse patchy opacities were found.
Moreover, 2 (18.2%) patients showed a complete upper lobe consolidation
on first CXR and were directly treated with MV; a second CXR was
performed to evaluate infant clinical course.
Analysing viruses’ detections, RSV was identified in 81.8% of patients
supported by MV and in 49.6% of patients underwent HFNC (Table 2).
On multivariate analysis adjusted for age, sex and RSV detection, the
significant independent risk factor for escalation to mechanical
ventilation was the presence of a complete upper right lobe
consolidation (Table 3). This result was confirmed when we added the
clinical severity score just before starting HFNC and PLT/MPV (data not
shown).