Hypoxia In Cardiac Arrest

Question 1

Causes of arrest in asthma

Answer 1

Severe bronchi spasm and mucous plugging causing asphyxia
Cardiac arrhythmias cause by hypoxia
Hyperinflation: auto-PEEP caused by air-trapping and breath staking (pressure builds reducing venous return)
Tension pneumothorax (maybe bilateral)

Question 2

Acute severe asthma

Answer 2

PEF 33-50%
RR >25
HR>110
Inability to complete sentences

Question 3

Life-threatening asthma

Answer 3

Altered GCS
Exhaustion
Arrhythmia
Hypotension
Cyanosis
Silent chest
Poor resp effort
PEF <33%
SpO2 <92
PaO2 <8
Normal PaCO2

Question 4

Near-fatal asthma

Answer 4

Raised PaCO2 and/or ventilation with raised inflation pressure

Question 5

Three criteria of anaphylaxis

Answer 5

1. Sudden onset and rapidly progressing
2. Life-threatening ABC problems
3. Skin and/or mucosal changes (flushing, urticaria, angioedema)

Question 6

Treatment of anaphylaxis

Answer 6

Adrenaline 0.5ml (500mcg) of 1:1000 adrenaline (= 1mg/ml) IM

Question 7

Action of adrenaline

Answer 7

Alpha agonist: reverses vasodilation, reduces oedema
Beta agonist: dilates bronchial airways, increases force of myocardial contraction, suppresses histamine and leukotriene release

Question 8

Escalation of adrenaline in anaphylaxis

Answer 8

IM adrenaline
Repeat after 5 minutes
If no improvement adrenaline infusion

Question 9

Recognising tension pneumothorax

Answer 9

Preceding resp distress or hypoxia
Haemodynamic compromise
Absent breath sounds on auscultation
Chest creps
Sub cut emphysema
Tracheal deviation
Jugular venous distension