Related Subjects: Asthma
|Acute Severe Asthma
|Exacerbation COPD
|Pulmonary Embolism
|Cardiogenic Pulmonary Oedema
|Pneumothorax
|Tension Pneumothorax
|Respiratory (Chest) infections Pneumonia
|Fat embolism
|Hyperventilation Syndrome
|ARDS
|Respiratory Failure
|Diabetic Ketoacidosis
Prevention is key and all patients at risk of severe exacerbations should have an individualised plan to manage any exacerbation early with Short-acting beta-agonists and oral steroids and seeking medical help.
Initial Status Asthmaticus Management Summary |
- ABC, Ensure O₂ 15 L/min non rebreathe and IV access
- Salbutamol [Albuterol] 5 mg Nebs or Terbutaline 10 mg Nebs every 15-30 mins with High flow O₂.
- Add Ipratropium bromide 0.5 mg 4-6 hrly Nebs
- Hydrocortisone 200 mg IV stat or Prednisolone 40 mg PO
- Consider Magnesium Sulphate 1.2-2.0 g over 20 mins IV
- Consider IV Salbutamol [Albuterol] 5-20 mcg/min or 250 microgram bolus over 1 minute
- Get input early if not responding. Criteria for ITU: see below
- Portable CXR and ABG. Senior help if fails to respond
|
Note: The fixed combination of an inhaled glucocorticoid and a LABA improves lung function, reduces the frequency and severity of exacerbations, and enhances the quality of life in patients with asthma.
About
- Asthma is a chronic disease characterized by intermittent reversible airway obstruction.
- The incidence appears to be increasing, but this is balanced by better management and access to inhaled steroids.
- Patients with acute severe asthma can suddenly deteriorate, so they should not be left unobserved by healthcare staff, even during procedures like imaging.
- Typical asthma symptoms include wheeze, shortness of breath, chest tightness, and cough.
Basics
- Ensure the patient is sitting up, supported, and as comfortable as possible. Reassurance and hydration are key, as well as encouraging slower and deeper respirations.
- A positive, confident, and competent attitude from staff can help greatly. The patient may be terrified and working hard to breathe, especially in severe cases.
- Monitor the patient closely in a well-staffed area with continuous ECG and O₂ saturation monitoring.
- Patients must be observed at all times, including during transfers (e.g., for chest X-ray) as rapid and sudden deterioration or cardiac arrest is possible.
Assessing Severity
- Acute Severe:
- SpO₂ >92%
- PEF 33-50% of predicted or PEF < 200 L/min
- Respiratory rate >25/min
- Heart rate >110/min
- Unable to complete sentences in one breath
- Life-threatening:
- PEF < 33% of predicted or SpO₂ < 92%
- ABG: PaO₂ < 8 kPa (60 mmHg) or normal/raised PaCO₂
- Signs: Silent chest, cyanosis, feeble respiratory effort, exhaustion
- Hypotension, bradycardia/arrhythmias
- Confusion or coma
- Near-fatal Asthma:
- Raised PaCO₂
- Need for intubation and mechanical ventilation
- Discharge Criteria:
- Symptoms, particularly nocturnal symptoms, have improved
- PEFR is ≥ 75% of best with diurnal variation < 25%
- Good expected compliance
- Home on inhaled steroids + oral corticosteroids
- Management plan for deterioration established
Chest X-ray Indications
- Not routinely recommended unless:
- Suspected pneumomediastinum
- Suspected pneumothorax
- Suspected consolidation
- Life-threatening asthma
- Failure to respond to treatment
- Requirement for ventilation
Management if PEFR < 50% and Signs of Acute Severe Asthma
- Admit the patient. Follow ABC protocol, start high-flow oxygen, and take senior advice. Consider ICU review if not responding within 15-20 minutes.
- Provide high-flow oxygen at 15 L/min to maintain target saturations of 92-94%. Use high-flow oxygen to drive nebulizers.
- Administer IV fluids to prevent dehydration, adding potassium if needed as salbutamol can lower serum potassium levels.
- Give IV antibiotics only if there is clear evidence of bacterial infection.
- Nebulized Salbutamol 5 mg every 15-20 minutes initially, then 1-2 hourly. Alternatively, use Terbutaline 5-10 mg via nebulizers.
- Nebulized Ipratropium Bromide 500 mcg (0.5 mg) every 4-6 hours, given with Salbutamol.
- Start Prednisolone 40-60 mg orally or Hydrocortisone 200 mg IV stat, followed by 100 mg IV every 6 hours or oral Prednisolone for at least 5 days.
- Avoid routine chest X-rays, blood gases, or antibiotics unless clearly indicated.
Management: PEFR >50% and No Signs of Acute Severe Asthma
- No features of acute severe asthma.
- Give up to 10 puffs of Salbutamol via a volumatic spacer device.
- Give Prednisolone 40 mg orally.
- Good Response: PEFR >75% in 1 hour. Continue Prednisolone 40-50 mg for 5 days. Ensure correct inhaler technique, prescribe inhaled corticosteroids (at least 400 mcg). Discharge home if stable.
- Partial Response: PEFR < 75% in 1 hour. Consider nebulized Salbutamol and IV magnesium. Continue Prednisolone 40 mg daily for 5 days. Admit if not improving. Seek senior advice if needed.
Further Management for Non-Responding Patients
- Administer Magnesium Sulphate 1.2-2.0 g (8 mmol) IV over 20 minutes for bronchodilation.
- Consider Aminophylline:
- Loading dose of 5 mg/kg IV over 20 minutes unless the patient is on oral theophylline.
- Maintenance dose of 0.5 mg/kg/hr with ECG monitoring.
- Aim for plasma concentrations of 10-20 mcg/mL (55-110 umol/L). Monitor for toxicity at levels >25 mcg/mL.
- Use Adrenaline 0.5 mg IM for bronchospasm as part of anaphylaxis (e.g., from allergens).
- Consider IV Salbutamol infusion at 5-20 mcg/min. Monitor for lactic acidosis, which can develop in 70% of patients within 2-4 hours.
- Intubation Criteria:
- Progressive exhaustion, drowsiness, or altered mental state.
- Respiratory arrest.
- PaO₂ < 8 kPa (60 mmHg) despite 60% oxygen.
- PaCO₂ >6 kPa (45 mmHg) with worsening acidosis.
- Early involvement of ICU for potential intubation and mechanical ventilation is critical.
Discharge Planning
- Ensure inhaler technique is correct and the patient has a preventer medication.
- Continue oral Prednisolone for 5-10 days.
- Review asthma maintenance treatment and provide smoking cessation advice.
- Stop nebulizers 24 hours before discharge.
- Provide a written, agreed action plan and ensure the patient has a PEF meter and diary.
- Arrange follow-up with GP, asthma nurse, or respiratory clinic within 4 weeks.
References