Asthma

Question 1

How to do you prepare an adrenaline infusion?

Answer 1

• Adrenaline 3mg in 50ml with Dextrose 5% or Normal Saline
• 1 mcg/min - 1ml/hr
• Dose: 2-15 mcg/min

Question 2

When can you consult the clinician for IV adrenaline?

Answer 2

• Thunderstorm asthma (if unresponsive to at least 1 dose of IM adrenaline)
  OR
• Orolingual oedema secondary to tPA infusion

Question 3

What is the preferred route of salbutamol?

Answer 3

Preferred route is pMDI in patients with mild or moderate respiratory distress.

If pMDI is not available, nebulise 5mg at 20min intervals as required

Question 4

How do you treat mild or moderate asthma?

Answer 4

Salbutamol pMDI and spacer

• Deliver 4-12 doses at 20 minute intervals until resolution of symptoms
• ensure patient takes 4 breaths per dose

Question 5

Recite the asthma CPG

Question 6

How do you treat severe asthma?

Answer 6

• salbutamol 10mg (5ml) and ipratropium bromide 500mcg (2ml) nebulised
  Repeat salbutamol 5mg (2.5ml) nebulised at 5 minute intervals if required
• Dexamethasone 8mg IV/Oral

if inadequate response (no response to nebulised therapy/speaking single words of acute life threat)

• Adrenaline 500mcg IM (1:1000)
• repeat 500mcg IM at 5-10min intervals (max 1.5mg)
• if no response to IM adrenaline, consult the clinician for IV adrenaline if thunderstorm asthma 20mcg at 2 minute intervals

If no response to IM adrenaline or Pt has inadequate ventilation
- MICA can admin further IV adrenaline and infusion

Question 7

Unconscious asthma notes

Answer 7

• High EtCO2 levels should be anticipated in the intubated asthmatic patient and are considered safe
• Despite EtCO2 levels, treatment should not be adjusted and managing ventilation should be conscious of the effect of gas trapping when attempting to reduce EtCO2
• Due to high intrathoracic pressure as a result of gas trapping, venous return is compromised and the patient may lose cardiac output. Apnoea allows the gas trapping to decrease

Question 8

What do you do if your asthmatic patient become unconscious but still has cardiac output?

Answer 8

Pt requires immediate assisted ventilation

• Ventilate VT 6-7ml/kg at 5-8 ventilations per minute
• moderately high respiratory pressures
• allow for prolonged expiratory phase

if adequate response
- treat as per severe respiratory distress

if inadequate response

• treat as per severe respiratory distress
• consider MICA for ETT
• monitor for signs of loss of cardiac output

Question 9

What do you do if your severe asthmatic patient loses cardiac output?

Answer 9

• allow for 1 minute of apnoea and prepare for potential resuscitation

If cardiac output returns
- treat as per Asthma

If carotid pulse but no BP
- MICA to administer Adrenaline IV and NaCl infusion

If no return of cardiac output
- treat as per cardiac arrest