The IX t h Makassed Medical Congress - American University of Beirut

T h e I X t h M a k a s e d M e d i c a l C o n g r e s s
and weaning off invasive ventilation, but there was only weak support for NIV in others, such as
immunocompromised patients. For other groups, such as patients with asthma, pneumonia, or
acute lung injury, RCT-level evidence was lacking or did not suggest benefit (6-8). More recently,
53 adult patients with severe acute asthma (FEV1 < 30% of predicted) were randomized to NIV
(n=28) or standard medical therapy (n=25). ICU and hospital stay was significantly shorter and
the mean dose of inhaled bronchodilator was significantly less in the NIV group. The four patients
with standard-medical-therapy failure improved with NIV. Two patients in the NIV arm required
invasive ventilation. There was no mortality in either of the arms. The authors concluded that a
larger study is required (9).
For children, there is little evidence from randomised controlled trials that early intervention with
NIV reduces mortality; however, a number of reports suggest that NIV is useful in ARF by avoiding
the need for intubation (10). In the prospective series by Yanez et al, comparing 25 children NIV plus
standard therapy (n=25) with standard therapy (n=25), diagnoses were moderate asthma (n=5),
viral bronchiolitis-pneumonia (n=42), bacterial peumonia (n=3). Tracheal intubation was lower in
the NIV group (28%/60%; p=0.045) (4). In another series, 20 children (mean age 48 months) with
lower airway obstruction were randomized to receive alternatively 2 hours of nasal NIV, followed
by crossover to 2 hours of standard medical treatment. Compared to the baseline values, NIV
was associated with lower respiratory rate, total Clinical Asthma Score, and delivered oxygen
concentration needed to maintain oxygen saturation ≥ 90% (all p < .01) (11). Viral bronchiolitispneumonia,
mainly due to RSV, represents the largest cohort of children treated with NIV (2, 4,
12-16). In all reported series (none of them was randomized and prospective), a decrease in
respiratory rate and pCO 2 level was usually observed within 1 or 2 hours, and 75-80% of infants did
not need intubation (15). Clinical conditions with ARF where NIV is used are summarized in table
2 (10). Finally, NIV may also be palliative.
Do we have predictive factors of NIV failure in children with acute respiratory failure?
In children with severe exhaustion from respiratory failure or reduced conscious level, there are
risks from treatment with NIV without an adequately secured airway, including gastric distension
and aspiration. NIV does not protect the airway or allow as effective clearance of lower airway
secretions as does intubation, particularly in the child with a reduced conscious level. However,
effective airway clearance is helped by any ventilation that allows maintenance of good lung
volumes from which a more effective cough may be generated.
The best predictive factors for the success of NIV in acute respiratory failure appear to be the
respiratory rate and the level of inspired oxygen 1 or 2 hours after starting NIV. Lack of effectiveness
arises mainly from agitation, poor airway protection or abdominal distension. Several authors
have identified different predictive factors of NIV failure in the PICU: the results of studies, which
regard children with ARF of different causes, are given in table 3. Other studies have focused on
only one disease such as bronchiolitis in infants (12-15). In conclusion, NIV is a treatment option
available for children experiencing acute respiratory failure. NIV needs an experienced staff and
is not appropriate for children who are unable to protect their own airway, severely exhausted
or have a reduced level of consciousness. The selection of the NIV interface is essential in order
to achieve the most successful outcome (17). Clinical assessment with continuous monitoring of
SpO 2 and if possible PtcCO 2 must be rigorous in order to identify patients not responding to NIV
and needing intubation.
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