Introduction:

Heliox (a mixture of 21% oxygen, 79% helium) has a lower density than air which allows movement of gas with less driving pressure and better ventilation down to the alveolar level. In paediatrics, heliox may be successfully used in the management of patients with croup, asthma, upper airway obstruction, bronchiolitis and post-extubation stridor.

Heliox in Post-extubation stridor:

A 10 month old infant (35 weeks gestation) with developmental delay and poorly controlled fits was admitted with respiratory failure requiring intubation. Following extubation she developed stridor within 15 minutes and was treated with heliox. Stridor score (modified Syracuse score) 1 was 9/11. Patient rapidly settled following heliox therapy, stridor score decreased to 4/11 and after 5 hours heliox was stopped. Patient required only 1 dose of nebulised adrenaline and heliox was used as the driving gas at a flow rate of 12 lt/min.

Heliox in Acute severe asthma:

A 2 year old child was admitted with an acute exacerbation of asthma with severe respiratory distress (RR 70/min, HR 190/min, PaO2 10.2 kPa on 6 I/min oxygen via non-rebreath mask, PaCO2 6.8 kPa). Severity was assessed by the modified Wood's asthma score 7/10)2. He was on high doses of intravenous salbutamol and aminophylline. He was started on Heliox with 40% oxygen and after 20 minutes there was an improvement in his respiratory rate, heart rate and recessions (RR-52/min, HR 154/min) and a reduction in asthma severity score to 4/10. ABGs showed a rise in PaO2 and fall in PaCO2. Heliox therapy was continued for 6 hours, requirements for bronchodilators decreased and he did not require ventilation.

Heliox in Croup:

A 2 years old girl with noisy breathing and fever presented to A & E with HR 180/min, RR 40/min saturation 90% in air. Stridor score on admission was 7/11 and helix was commenced immediately in A & E. There was a reduction in HR to 124/min, RR 32/min and increase in saturation to 94% within 10 minutes of starting heliox. Stridor score fell to zero after 7 hours of starting heliox and the patient did not require further nebulization with adrenaline an was discharged after 24 hrs observation.

Conclusion:

Heliox reduces respiratory distress in conditions with resistance to airflow. It has a potential for use as 1st line for many respiratory conditions in neonates and children averting need for PICU/NICU.

• Jacobs S. Validation of a croup score and its use in triaging children with croup. Anaesthesia. 1994 Oct;49(10):903-6.
• Wood DW. A clinical scoring system for the diagnosis of respiratory failure - Preliminary report on childhood status asthmaticus. Am J Dis Child. 1972 Mar;123(3):227-8.

NCPCC 2005 - Conference Abstracts.Pediatric Oncall [serial online] 2006 [cited 15 May 2006(Supplement 5)];3. Available from:
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Heliox.asp