Resp - Acute Severe Asthma

Question 1

Pt arrives with acute severe asthma attack- what Hx do you need?

Answer 1

• Precipitant: infection, travel, exercise
• Usual and recent Rx
• Previous attacks and severity: eg ICU?
• Best PEFR?

Question 2

Ix

Answer 2

• PEFR + pulse oximetry + ECG
• ABG: PaO2 (normal or low), PaCO2 (low)
• *If PaCO2 is high send to ITU for ventilation
• Bloods: FBC, CRP, blood cultures, U+E (Mg,phosphate and K+ [beta agonists and steroids can cause/precipitate hypokalaemia])

Question 3

Assessment: severe asthma criteria if any of following

Answer 3

• PEFR: <50% normal
• RR: >22
• HR: >110
• Can’t complete sentence in 1 breath

Question 4

Assessment: life threatening if any of the following

Answer 4

-PEFR: <33%
-SpO2: <92%, PCO2 > 4.6kPa, PaO2 <8 kPA
CHEST
-Cyanosis
-hypotension
-exhaustion/confusion
-silent chest/poor respiratory effort
-tachy/brady/arrhythmias

Question 5

Differential

Answer 5

• Acute exacerbation of COPD

- Pulmonary oedema

Question 6

Criteria for admission and discharge

Answer 6

• Admission: life threatening attack, severe attack Rx resistant
• Discharge: been stable on discharge meds for 24h, PEFR >75% with diurnal variability

Question 7

Discharge plan:

Answer 7

• TAME criteria (see chronic asthma)
• PO steroids: oral prednisolone 50mg OD for 5d
• GP app within 1 wk
• Resp clinic app within 1 month

Question 8

Pt in severe attack: initial Mx

Answer 8

• High dependency/resus area in A&E
• ECG, SaO2 and non invasive BP recording = minimum Obs
• High flow O2: aim above 92%
• Nebulisers: O2 driven B2agonist (may need repeat/continuous bonuses), Ipratropium bromide
• Steroids: either 40/50mg prednisolone PO or IV hydrocortisone (100mg )

Question 9

Pt in severe attack: if pt improves after initial Mx

Answer 9

• Monitor SpO2 at >92%, PEFR
• Continue pred 50mg OD for 5d
• Nebulised salbutamol every 4h

Question 10

Pt in severe attack: if life threatening

Answer 10

• Inform ITU
• MgSO4 2g IV over 20 mins (not faster!): blocks bronchial SM Ca channels and stabilises lymphocyte and mast cells
• Nebulised salbutamol every 15 mins with ECG monitoring

Question 11

Pt in severe attack: if no improvement in 15-30 mins

Answer 11

• Continue nebulised salbutamol every 15 min
• Continue ipratropium 4-6hourly
• Consider aminophylline (must monitor serum theophylline levels if pt already taking theophylline)
• ITU transfer for invasive ventilation