GGC Medicines

Adult Therapeutics Handbook

Management of Acute Severe Asthma in Adults in Hospital

Management of Acute Severe Asthma in Adults in Hospital

Scottish Intercollegiate Guidelines Network (SIGN). British Guidelines on the Management of Asthma. Edinburgh: SIGN; revised Jan 2012. (no. 101). Available from Algorithm adapted with permission from the British Thoracic Society (# denotes minor changes).

Features of acute severe asthma:
  • Peak expiratory flow (PEF) 33–50% of best (use % predicted if recent best unknown).
  • Can't complete sentences in one breath.
  • Respiration >25breaths/minute.
  • Pulse >110beats/minute.
Life-threatening features:
  • PEF <33% of best or predicted.
  • SpO2 <92%
  • Silent chest, cyanosis, or feeble respiratory effort.
  • Bradycardia, dysrhythmia, or hypotension. #
  • Exhaustion, confusion, or coma. #

If patient has any life-threatening feature:

Measure arterial blood gases. No other investigations are needed for immediate management.

Blood gas markers of a life-threatening attack:

  • Normal (4.6–6kPa, 35–45mmHg) PaCO2
  • Severe hypoxia: PaO2 <8kPa (60mmHg) irrespective of treatment with oxygen.
  • A low pH (or high H+).

Caution: Patients with severe or life-threatening attacks may not be distressed and may not have all these abnormalities. The presence of any should alert the doctor.

Near fatal asthma:
  • Raised PaCO2
  • Requiring IPPV with raised inflation pressures. #
  • Oxygen to maintain SpO2 94–98%. (CO2 retention is not usually aggravated by oxygen therapy in asthma). #
  • Salbutamol 5mg or terbutaline 10mg via an oxygen-driven nebuliser.
  • Ipratropium bromide 0.5mg via an oxygen-driven nebuliser.
  • Prednisolone oral 40–50mg or hydrocortisone IV 100mg or both if very ill. #
  • No sedatives of any kind.
  • Chest radiograph only if pneumothorax or consolidation are suspected or patient requires IPPV. #
  • Discuss with senior clinician and ICU team.
  • Add IV magnesium sulphate 1.2–2g infusion over 20 minutes (unless already given).
  • Give nebulised Beta2 agonist more frequently e.g. salbutamol 5mg up to every 15–30 minutes or 10mg continuously hourly. #
  • Oxygen to maintain SpO2 94–98%.
  • Prednisolone oral 40–50mg each day or hydrocortisone IV 100mg 6 hourly.
  • Nebulised Beta2 agonist and ipratropium 4–6 hourly.
  • Continue oxygen and steroids.
  • Give nebulised Beta2 agonist more frequently e.g. salbutamol 5mg up to every 15–30 minutes #
  • Continue ipratropium 0.5mg 4–6 hourly until patient is improving.
  • Discuss patient with senior clinician and ICU team.
  • IV magnesium sulphate 1.2–2g over 20 minutes (unless already given). #
  • Senior clinician may consider use of IV Salbutamol or IV aminophylline or progression to IPPV (see Appendix 2 for details on preparation and administration).
  • Repeat measurement of PEF 15–30 minutes after starting treatment.
  • Oximetry: maintain SpO2 94–98%.
  • Repeat blood gas measurements within 1 hour of starting treatment if:
    • initial PaO2 <8kpa (60mmHg) unless subsequent SpO2 >92%
    • PaCO2 normal or raised
    • patient deteriorates
  • Chart PEF before and after giving Beta2 agonists and at least 4 times daily during hospital stay.

Transfer to ICU accompanied by doctor prepared to intubate if:

  • Deteriorating PEF, worsening or persisting hypoxia, or hypercapnea.
  • Exhaustion, feeble respirations, confusion or drowsiness. #
  • Coma or respiratory arrest. #

When discharged from hospital, patients should have:

  • Been on discharge medication for 24 hours and have had inhaler technique checked and recorded.
  • PEF >75% of best or predicted and PEF diurnal variability <25% unless discharge is agreed with respiratory physician.
  • Treatment with oral and inhaled steroids in addition to bronchodilators.
  • Own PEF meter and written asthma action plan.
  • GP follow up arranged within 2 working days.
  • Follow up appointment in respiratory clinic within 4 weeks.

Patients with severe asthma (indicated by need for admission) and adverse behavioural or psychological features are at risk of further severe or fatal attacks:

  • Determine reason(s) for exacerbation and admission.
  • Send details of admission, discharge and potential best PEF to GP.

Please refer all patients admitted with a new diagnosis or exacerbation of asthma to the respiratory nurse specialists for education and inhaler technique prior to discharge.

For peak expiratory flow in normal adults, see the peak flow chart