Makindo Medical Notes.com

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.

About

• Asthma, is a chronic disease characterised by intermittent reversible airways obstruction
• The incidence appears to be increasing but this has been balanced by better management and access to inhaled steroids
• Patients should not be left unobserved by healthcare staff for any period of time e.g. in radiology.
• Patients with Acute severe asthma can suddenly deteriorate.
• Typical asthma symptoms are wheeze, shortness of breath, chest tightness, cough

Basics

• Ensure patient sitting up and supported and as comfortable as possible, reassurance, hydration, encourage slower and deeper respirations
• A positive confident competent attitude from staff can help greatly. The patient is working hard and in extremis and often terrified.
• Monitor closely in a well-staffed area and continuous ECG and O₂ sats monitoring.
• Patient must be observed at all times (e.g. if they need a CXR they must be accompanied by staff and treatment continued) as rapid and sudden deterioration and cardiac arrest is possible.

Assessing severity

• Acute Severe
  • SpO₂ > 92%
  • PEF 33-50% predicted or PEF < 200 L/min
  • Resp rate > 25/min
  • Heart rate > 110/min
  • Unable to complete sentence one breath
• Life threatening
  • PEF < 33% predicted or SpO₂< 92%
  • ABG: PaO₂ < 8 kPa (60 mmHg) or Normal or raised PaCO₂
  • Silent chest, Cyanosis, Feeble respiratory effort, Exhaustion
  • Hypotension, Bradycardia/arrhythmias
  • Confusion, Coma
• Near fatal Asthma
  • Raised PaCO₂
  • Need for intubation and mechanical ventilation
• Discharge
  • Symptoms, particularly nocturnal symptoms, have improved
  • PEFR is 75% of best. Diurnal variation (i.e. ‘morning dips’) <25%.
  • Improving and compliance is expected to be good
  • Home on Inhaled steroids + Oral + Inhaler technique checked
  • Management plan for deterioration

Chest X-ray is 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% of best or predicted and signs of Acute Severe Asthma

• Admit, ABC High flow O₂, Take senior advice and consider ITU review if failing to respond in 15-20 mins
• High flow O₂ at 15 l/min target sat of 94-98%. Always use high flow O₂ to drive nebulisers.
• IV fluids to avoid dehydration. Add some 20 mmol K per litre as Salbutamol [Albuterol] can lower serum potassium.
• IV Antibiotics if clear evidence of Bacterial infection.
• Nebulised Salbutamol [Albuterol] 5mg repeated every 15-20 minutes initially and then 1-2 hourly. Alternative is Terbutaline 5-10 mg given as nebulisers with high flow O₂
• Nebulised Ipratropium bromide 500 mcg (0.5 mg) 4-6 hourly given with Salbutamol [Albuterol]
• Prednisolone 40-60 mg stat orally or Hydrocortisone 200 mg IV stat and then 100 mg IV 6 hourly or as oral Prednisolone until recovery (min 5 days)
• Do not routinely perform chest X-ray or blood gases, or routinely prescribe antibiotics, for asthma exacerbations.

Management : PEFR > 50% and no signs of Acute Severe Asthma

• No features of Acute Severe Asthma
• Give up to 10 puffs of Salbutamol [Albuterol] via volumatic spacer device
• Give Prednisolone 40 mg PO
  • Good response: PEFR > 75% in 1 hour. Continue Prednisolone 40-50 mg for 5 days. Check inhaler technique, check compliance. Ensure inhaled corticosteroids prescribed at least 400 micrograms. Advice to return if relapse. Can get home
  • Response: PEFR < 75% in 1 hour. Give Salbutamol [Albuterol] 2.5 mg - 5 mg nebulisers. Consider IV magnesium. Continue Prednisolone 40 mg OD for 5 days. Admit if not responding. Take advice if unsure.

Failing to respond please take senior advice. Ensure patient is on telemetry and in an area getting high level nursing care

• Magnesium Sulphate 1.2 - 2.0 g (8 mmol) over 20 mins IV may help FEV1.
• Aminophylline
  • Consider loading dose of 5 mg/kg IV bolus over 20 mins unless already on oral aminophylline or theophylline. ECG monitor. For those already on the drug a maintenance dose of 0.5 mg/hr may be considered with expert advice.
  • Aim for plasma concentration of 10-20mcg/mL (55-110umol/L). Can cause low BP arrhythmias, cardiac arrest at concentrations > 25mcg/mL. Watch K.
• Adrenaline 0.5 mg IM If bronchospasm as part of anaphylaxis reaction e.g. peanut or bee sting.
• Salbutamol [Albuterol] IV may be considered at 5-20 micrograms per minute. Watch serum lactic acidosis will develop in 2-4 hrs in 70%.
• Intubation and Mechanical ventilation criteria. Involve ITU/Outreach early well BEFORE this stage so they are fully aware of patient and can admit quickly as needed
  • Progressive exhaustion, comatose, drowsy, delirium
  • Respiratory arrest
  • PaO₂ <8 kPa despite FiO₂ of 0.6
  • PaCO₂ >6 kPa
  • Acidosis
  • Exhausted, delirium, drowsiness

Discharge Planning

• Check inhaler technique and ensure has a preventer medication
• Continue Oral Prednisolone for 5-10 days
• Review asthma maintenance treatment
• Smoking cessation advice
• Allergen avoidance
• Stop nebulisers 24 hrs before discharge
• Written agreed action plan
• PEF meter and diary
• GP/Asthma nurse and Respiratory clinic follow up in 4 weeks

References

• Global Initiative for Asthma Management and Prevention for adults and children older than 5 years. Updated 2019
• Holguin F, Cardet JC, Chung KF, et al. Management of Severe Asthma: a European Respiratory Society/American Thoracic Society Guideline. Eur Respir J2019; in press