Asma Flashcards
Near fatal asthma
Moderate asth|Acute severe asth|Life-threatening asth|Near fatal asth
Near fatal asthma:
* Raised PaCO2
* Requiring mechanical ventilation with raised inflation pressures.
Aminophylline
Aminophylline
Loading dose 5mg/kg; add dose to 100ml glucose 5% or sodium chloride 0.9%
Maintenance infusion
0.5mg/kg/hour; Add 500mg (20ml) to 500ml glucose 5% or sodium chloride 0.9%
Salbutamol (infusion solution 5mg/5ml)
- Salbutamol (infusion solution 5mg/5ml)
- Initially 5microgram/minute adjusted according to response and heart rate. Usual range 3-20microgram/minute.
Preparation
* Dilute 5ml of solution with 500ml glucose 5% or sodium chloride 0.9% (concentration = 10 microgram/ml)
Infusion Rate (ml/hour) 18 30 48 60 90 120
ASMA
Moderate asthma
Moderate asth|Acute severe asth|Life-threatening asth|Near fatal asth
- PEF >50–75% best or predicted
- SpO2 ≥92%
- Respiration <25/min
- Pulse <110 beats/min
- Can complete sentence in one breath
Acute severe asthma
Moderate asth|Acute severe asth|Life-threatening asth|Near fatal asth
- PEF 33–50% best or predicted
- Features of severe asthma:
1. PEF<50% best or predicted
2. Respiration ≥25/min
3. Pulse ≥110 beats/min
4. Cannot complete sentence in one breath
5. SpO2 ≥92%
Life-threatening asthma
Moderate asth|Acute severe asth|Life-threatening asth|Near fatal asth
- PEF <33% best or predicted
- Exhaustion, altered consciousness
- SpO2<92%, Cyanosis
- Poor respiratory effort, Silent chest
- Arrhythmia, hypotension
PEF & Asthma
Moderate asthma: PEF >50–75% best or predicted
Acute severe asthma: PEF 33–50% best or predicted
Life-threatening asthma: PEF <33% best or predicted
Moderate asthma - Treatment
Give β2 bronchodilator via spacer (give one puff at a time; according to response, give another puff every 60 seconds up to maximum of 10 puffs)
Blood gas markers of a life-threatening asthma attack
*PaCO2 ‘Normal’ (4.6–6 kPa, 35–45 mmHg)
* Severe hypoxia: PaO2 < 60 mmHg irrespective of treatment with oxygen
* A low pH (or high H+)
IMMEDIATE TREATMENT of acute asthma 1/2
IMMEDIATE TREATMENT|SUBSEQUENT MANAGEMENT| MONITORING
- Oxygen to maintain SpO2 94–98%
- β2 bronchodilator (salbutamol 5 mg) via an oxygen-driven nebuliser
- Ipratropium bromide 0.5 mg via an oxygen-driven nebuliser
- Prednisolone tablets 40–50 mg or IV hydrocortisone 100 mg
- No sedatives of any kind
- Chest X-ray if pneumothorax or consolidation are suspected or patient requires mechanical ventilation
IMMEDIATE TREATMENT of acute asthma 2/2
IMMEDIATE TREATMENT|SUBSEQUENT MANAGEMENT| MONITORING
FIRST 1/2:
SpO2 94–98%; salbutamol 5 mg; Ipratropium bromide 0.5 mg via an oxygen-driven nebuliser; IV hydrocortisone 100 mg
IF LIFE-THREATENING FEATURES ARE PRESENT:
1. IV magnesium sulphate 1.2–2 g infusion over 20 minutes
2. salbutamol 5 mg up to every 15-30 minutes
3. OR 10 mg per hour via continuous nebulisation (requires special nebuliser)
SUBSEQUENT MANAGEMENT of acute asthma 1/2
— NOT IMPROVING—
IMMEDIATE TREATMENT|SUBSEQUENT MANAGEMENT| MONITORING
- Continue oxygen and steroids
- Nebulised salbutamol 5 mg every 15–30
minutes; - Ipratropium 0.5 mg 4–6 hourly until patient is improving
- Use continuous nebulisation of salbutamol at 5–10 mg/hour if an appropriate nebuliser is available.
SUBSEQUENT MANAGEMENT of acute asthma 2/2
— NOT IMPROVING—
IMMEDIATE TREATMENT|SUBSEQUENT MANAGEMENT| MONITORING
IF PATIENT IS STILL NOT IMPROVING:
* ICU team
* IV magnesium sulphate 1.2–2 g over 20 minutes (unless already given)
* IV β2 bronchodilator or IV aminophylline or mechanical ventilation
SUBSEQUENT MANAGEMENT of acute asthma
— IMPROVING—
IMMEDIATE TREATMENT|SUBSEQUENT MANAGEMENT| MONITORING
IF PATIENT IS IMPROVING continue:
* Oxygen to maintain SpO2 94–98%
* Prednisolone 40–50mg daily or IV hydrocortisone 100 mg 6 hourly
* Nebulised β2 bronchodilator with ipratropium 4–6 hourly
