Asthma

Pathophysiology

Therapy

Beta Agonist Therapy

• MOA: B2 agonistic effects causing bronchodilation

• Albuterol: MDI, Nebulizer, continuous

• Terbutaline: IV, IM, SubQ

• Epinephrine: IV, IM, SubQ

• Home: Albuterol q4hrs

• Floors: Albuterol <q4hrs, O2 requirement

• PICU: Albuterol <q2hrs, any oxygen with PEEP

Anti-muscarinic cholinergic therapy

• MOA: Anti-muscarinic (M3) properties decreasing bronchoconstriction

Steroids for Inflammation

• Takes approximately 4-6hrs to take effect

• Prednisone converted via liver enzymes to prednisolone before it can work

• Prednisolone is a liquid suspension in dextrose which kids love (Cherry flavor, lets goooo)

• Caution in diabetes

Magnesium

• Inhibits calcium influx into cells, which decreases release of norepinephrine release causing vasoconstriction.

Oxygen Therapy Options

• If their saturations are good, they probably aren't hypercarbic

• PAO2 = (Patm - PH2O) x FiO2 - PaCO2 / RQ

• 90 = (713) x 0.21 - PaCO2 / 0.8

• -60 = -PaCO2/0.8

• PaCO2 = 48

• O2 Delivery Systems

• Understanding IPAP and EPAP in BiPAP

  • Standard initial settings 10/5 40%

  • Do NOT set it and forget it

  • IPAP: overcoming a resistive airway

  • EPAP: Keep those stupid alveoli open so gas exchange can occur

  • Obstructive airway disease is often an IPAP/delta problem

• Intubation Strategies

  • Consider.... not doing it. BUT don't delay in crashing patient

  • Ketamine as induction agent:

    • positive hemodynamics

    • Protects airway reflexes

    • bronchodilatory effects

    • but consider whether they actually have catecholamines to release

  • Remember what does not have analgesic effects (etomidate, Propofol)

  • Ketamine facilitated vs. DSI vs. RSI

Rescue Therapies

References

• Cat Urban​

• Grace Ker​

• ChatGPT​

• DALL-E

Joshua Mcgough, MD