Heliox Driven Nebulization Therapy for Severe Acute Pediatric Asthma Exacerbations: Heliox 202 for the Advanced Health Care Provider

Heliox Driven Albuterol Therapy Guidelines

     Consider heliox driven albuterol therapy in asthmatic patients who have moderate to severe asthma exacerbations.

Practical Considerations (When should one consider using this therapy):

• If considering IV magnesium bolus-> patient is a possible candidate for heliox driven albuterol therapy

• If patient is concerning enough to place in Critical Care Room-> Likely candidate for heliox driven albuterol therapy

• If mentally calculating ETT size and intubation drugs-> Definite candidate for heliox driven albuterol therapy

Suggested sequence of events to optimize heliox driven albuterol therapy.

1. Start by placing patient on standard albuterol nebulization driven by 100% oxygen (either 1-time 5 mg treatment or hour long treatment, 10-20 mg/hr of weight based dosing).

2. In near-intubatable patients, consider SQ terbutaline (0.01 mg/kg, max 0.3 mg)

or SQ epinephrine (0.01 mg/kg, max 0.3 mg)

3. Ask RT to setup large volume nebulizer (takes 5-10 minutes) with age appropriate albuterol dosing.

1. Note: If no RT present, do not attempt to setup heliox nebulizer, utilize other therapies.

                ii. Order can be written: “Heliox driven albuterol at __ mg/hr via 70:30 heliox.”

4. Secure IV access and administer 2 mg/kg solumedrol IV bolus (max 125 mg) with a 20 mL/kg bolus of Normal Saline (Patients may have some degree of dehydration from ↑ insensible losses from tachpynea)

5. Utilize non-rebreather mask to minimize heliox loss and optimize aerosol delivery. Adjust mask to get best fit.

6. Start nebulization with blender set at 50%. You will be giving a 50:50 heliox (50% helium: 50% oxygen). This approach allows you to assess the level of hypoxemia in the patient. If pulse oximetry < 91% on 50:50 heliox, consider patient a heliox failure and place on standard 100% FiO₂ driven albuterol nebulization. If patients fails 50:50 heliox, you can dial up blender to 100% to give 100% FiO2 while setting up standard nebulization set up.

7. Adjust blender (if patients pulse oximetry > 95%) every 10 minutes by 10% increments (From 50:50 heliox to 60:40 heliox to 70:30 heliox). Patients can tolerate well pulse oximetry > 92%. Reassess with each 10% titration.

• Patients often improve after 30-45 minutes of heliox driven albuterol therapy and can be decreased on their oxygen FiO2 while being increased on their helium concentration. Target 70:30 heliox. Approximately 5-10% patients will require a higher FiO2 concentration of 60:40 or 50:50 heliox.

• If patient improves to 70:30 heliox and is stable, I would recommend keeping them on this mixture until they are ready to go to Intermediate ICU/PICU. If patients are boarding in the ED >6 hours, the large volume nebulizer may need to be replenished. Some patients after 3-6 hours of heliox driven albuterol therapy improve enough to come off continuous therapy and can be admitted to the floor.

•At present, patients admitted to the Intermediate ICU/PICU can be placed on standard albuterol nebulization for transfer to the Intermediate ICU/PICU. Heliox driven albuterol units with blenders stay in our emergency department.

8. Heliox can be used in conjunction with IV magnesium or IV terbutaline. Most patients improve on heliox driven albuterol therapy without these therapies. But, consider in the patient who is refractory (likely modified β-agonist receptors).

We usually escalate to IV magnesium (50 mg/kg IV infusion over 30 minutes, max 2 gm) then IV terbutaline (10 mcgm/kg bolus followed by 1 mcgm/kg/min continuous infusion, max 6 mcgm/kg/min; Be careful of ↓ diastolic BP at higher terbutaline dosing.

Approximately 5-10% of asthma patients have modified β-agonist receptors that may lead them to be refractory to albuterol based therapies (and heliox driven albuterol therapy).

9. If admitting to intermediate ICU or pediatric ICU, consider portable Chest X-ray.

NOT Recommended:

• In general, we do NOT use heliox driven albuterol therapy straight off a 70:30 tank without a blender since 5-10% of patient will require additional oxygen blended into the 70:30 heliox. The high pressure gas line, with the blender system, avoids pressures which can disconnect plastic tubing lines.

 • Do NOT use tanks that have not been in room air for at least 4 hours. Tanks straight from the outside tank farm may be cold or warm depending on environmental temperatures that may exacerbate respiratory symptoms. Tanks from an internal tank farm at room temperature can be used immediately.