2006 OPEN FORUM Abstracts
HELIOX (HeO2) Use with a nasal cannula (NC) for Acute airway edema and post extubation stridor
Christina Collin RRT-NPS,
Robert DiBlasi RRT-NPS, John Salyer RRT-NPS, MBA, FAARC. Respiratory Care
Department. Children's Hospital and
Regional
Medical
Center
,
Seattle
WA
.
Introduction: Inhaled HeO2 has been used to reduce symptoms created by
airflow obstruction in pediatric respiratory disease. The lower density of helium
versus nitrogen allows for a reduction in work of breathing (WOB). This therapy
is usually administered to spontaneously breathing patients via non-rebreathing
mask, oxygen tent, or hood. However, these devices are sometimes not well
tolerated by children. We report the use of HeO2 via NC in a patient
with acute airway edema & subsequent stridor.
Case Report: A 4 month old male with
congenital left frontonasal encephalocele was admitted for a 9.5 hour surgical
repair. He was intubated in the O.R. with a cuffed 3.5 ETT. After surgery the
patient was in the PICU on a ventilator, where he remained intubated overnight
for airway protection. On the second day after surgery, a dose of dexamethasone
was given at 0600 in anticipation of extubation. Morphine and lorazepam drips were
given for agitation and ventilator dysynchrony. At 0900, the lorazepam and morphine
drips were decreased and the patient was extubated at 0930 and immediately
developed severe respiratory distress including: supra-substernal and
intercostal retractions, marked inspiratory stridor, nasal flaring, and severely
diminished breath sounds. The patient could not be nasally suctioned due to post
operative restrictions mandated by the surgeons. The lorazepam was discontinued
and the morphine was decreased. At 0940, a racemic epinephrine nebulizer
treatment was given via nebulizer. Diminished breath sounds and upper airway
stridor persisted. The patient was placed on mask
CPAP via manual
resuscitator. Clinical staff began preparing for reintubation. Naloxone
was given followed by another dose of dexamethasone. The patient became more
alert. Another racemic epinephrine treatment was given. HeO2 was started via NC
@ 2 L/m of a 70/30% mixture. Stridor and WOB improved slightly but the patient
became agitated. The morphine drip was increased. Breath sounds improved
and inspiratory stridor and WOB diminished significantly. Discontinuation of HeO2 was attempted
but there was an immediate increase in WOB and stridor. HeO2 was changed to 1 L/m at
a 25/75% at 1500. The patient was given a third dose of dexamethasone and was changed
to 80/20 mixture and weaned completely by 1830.
| Time Line | Comment | pH | PaCO2 | PaO2 |
| 0930 | Extubation | severe respiratory distress | ||
| 0940 | Mask CPAP | 7.19 | 61 | 61 |
| 1000 | HeO2 70/30 @ 2 L/m | 7.25 | 42 | 112 |
| 1500 | HeO2 75/25 @ 1 L/m | 7.33 | 37 | 138 |
| 1630 | HeO2 80/20 @ 1 L/m | ¯ work of breathing ¯ stridor | ||
| 1830 | Room air | |||
Discussion: Avoiding reintubation in
pediatric patients with post-extubation airway edema can be a clinically
challenging. HeO2 via NC appears to have helped this patient avoid
reintubation until IV steroids were able to take effect. However, racemic epinephrine was also given,
and may have contributed to this patient's improvement. This apparent effectiveness
of the administration of HeO2 through a nasal cannula may be due in
part to the low inspiratory flow rates and obligatory nasal breathing patterns
that are often observed in the pediatric population. Both of these factors
would have contributed to a low rate of entrainment of ambient air and thus
kept the inspired concentration of HeO2 as high as possible.