Acute Asthma Flashcards
What is acute asthma?
An acute exacerbation of asthma is characterized by a rapid deterioration in symptoms.
Acute asthma triggers include
typical asthma triggers such as infection, exercise, or cold weather
What are some patient presentations that would indicate acute asthma?
- Progressively worsening shortness of breath
- Use of accessory muscles
- Fast respiratory rate (Tachypnoea)
- Symmetrical expiratory wheeze on auscultation
- The chest can sound “tight” on auscultation with reduced air entry
When should a patient be hospitalized after an acute asthma attack?
If it is moderate/severe
What physiological values would you expect to see in a patient with mild/moderate acute asthma?
- PEFR 50-75% predicted
What physiological values would you expect to see in a patient with severe acute asthma?
- PEFR 33-50% predicted
- Respiratory rate > 25
- Heart rate > 110
- Unable to complete sentences
What physiological values would you expect to see in a patient with life-threatening acute asthma?
- PEFR < 33%
- Oxygen Saturation < 92%
- Becoming tired
- Heart rate > 130 (Bradycardiac)
- No wheeze. This occurs when the airways are so tight there is no entry at all. This is ominously described as a “silent chest”
- Haemodynamic instability (i.e. shock)
- Grunting
- Hypoventilating
- Cyanosis
What physiological values would you expect to see in a patient with near-fatal acute asthma?
Raised partial pressure of carbon dioxide
What treatment options are available for patients suffering from moderate acute asthma?
- Nebulised Beta-2 agonists (i.e. salbutamol 5mg repeated as often as required)
- Nebulised Ipratropium Bromide
- Steroids. Oral Prednisolone or IV hydrocortisone. Usually continued for 5 days.
- Antibiotics if there is convincing evidence of bacterial infection
What treatment options are available for patients suffering from severe acute asthma?
- Oxygen if required to maintain sats 94-98%
- Aminophylline infusion
- Consider IV salbutamol
What treatment options are available for patients suffering life-threatening acute asthma?
- IV magnesium sulfate infusion
- Admission to HDU or ICU
- Intubation in the worst cases. This decision should be made early because it is very difficult to intubate with severe bronchoconstriction
What does near-fatal asthma require?
Mechanical ventilation
What are the ABG’s in asthma?
Initially, patients will have a respiratory alkalosis as tachypnoea causes a drop in CO2. A normal PCO2 or hypoxia is a concerning sign as it means they are tiring, it indicates life-threatening asthma. A respiratory acidosis due to high CO2 is a very bad sign in asthma.
How can you monitor the responses to treatment?
- Respiratory Rate
- Respiratory Effort
- Peak flow
- Oxygen saturation
- Chest auscultation
Why should you monitor serum potassium when on salbutamol?
Salbutamol causes potassium to be absorbed from the blood into the cells. It also causes tachycardia.