High flow nasal cannula versus non-invasive ventilation in severe
asthma: two years prospective observational study.
Abstract
Background: in recent years, High Flow Nasal Cannula (HFNC) has been
considered an alternative to non-invasive mechanical ventilation (NIMV)
in severe asthma respiratory management in children. Objective: to
describe the use of HFNC in children with severe asthma admitted to
pediatric critical care unit (PICU). To compare its clinical
characteristic and evolution with those receiving NIMV or other
respiratory support. Methods: prospective observational study done in
children admitted to PICU with severe asthma (October 2017 to October
2019). Data collected: epidemiological, clinical, respiratory support,
thorax x-ray, pharmacological treatments and days of admission. Patients
were divided into groups: 1) Only HFNC 2) HFNC and NIMV, and 3) Only
NIMV. Results: Seventy-six patients included, 39 girls. The median age
was two years and one month (range 160). The median pulmonary score was
5 (range 7). PICU admission lengths a median of 3 days (range 9),
hospital 6 days (range 23). There were no epidemiological or clinical
differences between groups. Children with only HNFC showed a shorter
time of PICU days (p 0,025) and none of them required NIMV. In the group
receiving both modalities, NIMV was used first and then HFNC in all
cases. Children with HFNC showed higher SaO2/FiO2 ratio (p=0,025) and
lower PCO2 level (p=0,032). There were no deaths. Conclusions: in our
study the HFNC did not require escalation to NIMV and did not increase
the length of PICU or hospital days. Normal initial blood gases and
absence of high oxygen requirements were useful to select responders to
HNFC.