You do an ABG on room air:

• pH 7.42 (7.35-7.45)
• pCO2 3.1 (4.4-6.5)
• pO2 10.0 (10.0-15.0)
• HCO3 27 (24-28)

You paid attention in med school and correctly identify that your patient is hyperventilating. You expected the pO2 to be slightly higher in a patient who is hyperventilating so this time you put the patient on oxygen yourself.

You measure your patients peak flow at 200 (patient’s normal around 500) and confirm to yourself that this is indeed acute severe asthma.

Because you are know what you are doing, you know that a chest x-ray is not routinely indicated at this stage in acute severe asthma.

Remembering the distress on your patient’s face you start writing them up for:

Salbutamol 5mg nebs, ipratropium 500mcg nebs, hydrocortisone 200mg IV

Salbutamol 2.5-5mg nebs, saline 5mg nebs, prednisolone 50mg oral

Salbutamol 5mg nebs, ipratropium 5mg nebs, prednisolone 40mg oral