Acute severe asthma

Acute severe asthma : who is at most risk ? Previous life-threatening attacks Severe disease (3 or >3 drugs for control; emergency steroid in past ; ever admitted in last 1 year) Psychiatric morbidity Non-compliance Requiring 2 or > 2 Bronchodilator inhalers monthly

Near fatal episodes Misuse of drugs/alcohol Psychiatric illness Denial Non compliance Learning difficulties Previous admission to ICU for asthma Brittle asthma Social isolation, income and employment difficulties Previous self discharge from hospital Br Med J 2005;330585-9

What is acute severe asthma ? ANYONE OF: PEF 33-50% best or predicted RR 25/min Heart rate  110/min Inability to complete sentences in one breath

What is life threatening asthma ? ANYONE OF: PEF < 33% best or predicted Sat O2 < 92% PaO2< 55 mm Hg Normal PaCO2 Silent chest Cyanosis Feeble respiratory effort Heart rate  110/min Inability to complete sentences in one breath

Contd……. Bradycardia Dysrhythmia Hypotension Exhaustion Confusion Coma

What is near fatal asthma? Increased PaCO2 Requiring mechanical ventilation

What is brittle asthma? Type 1… > 40% diurnal variability in PEF for > 50% of the time over a period > 150 days despite intense therapy Type 2 … sudden severe attacks on a background of apparently well controlled asthma

Criteria for hospital admission Near fatal attack  ADMIT IN ICU Life threatening attack  ADMIT IN ICU Severe attack persisting after initial treatment Previous near fatal or brittle attack Concerns about compliance Living alone Psychological problems Physical disability / learning difficulty Pregnancy Presentation at night

Hospital Treatment – Immediate action CBC (to r/o infection) Chest X-ray (to r/o pneumothorax) Oxygen (40-60%) β2 agonist –nebulised or MDI + spacer Inhaled Ipratropium can be added if required Systemic steroid (Prednisolone / Hydrocortisone) Inhaled steroids to be continued or started as soon as posible Avoid sedation

Nebulised salbutamol 5 mg or 0.15 - 0.3 mg/kg salbutamol hourly (to a maximum of 10 mg per hour have been used in trials so far) Nebulised Ipratropium bromide 250-500 mcg 6 hourly

Acute severe asthma…continues Oxygen continues Nebulised ß2-agonist (5 mg salbutamol every 20 minutes or continuously at 5-10mg/hr) Nebulised ipratropium bromide (500 mcg 4-6 hrly ) Combination of above two

Acute severe Asthma Treatment (Contd.) Obtain IV access Start steroids (4 mg/kg hydrocortisone loading dose, then 100 mg 6 hrly) Antibiotics ( not routinely ) Adequate hydration Still deteriorating - Start Aminophylline infusion (0.5 - 0.7 mg/kg/hr)

Acute severe Asthma Treatment (Contd.) Adrenaline (0.1 mg sc) Cautious CPAP (ideally BiPAP) Mechanical ventilation 6 - 10 RR Low TV (6 - 10 ml / kg) I:E ratio 1:3 or longer Maintain PaO2 > 60 mmHg Allow PaCO2 to rise, provided pH > 7.2 Adequate sedation and paralysis

Management of acute severe Asthma in children > 2 years High O2 concentrations β2 agonist –nebulised or MDI + spacer Systemic steroids ( Oral / IV ) IV Bronchodilators ( Salbutamol 15μg/kg bolus or continuous infusion of 1-2μg/kg/min upto 5μg/kg/min in PICU)

Treatment (general practice) Oxygen (Check Room air O2 saturation if available) Nebulised salbutamol 5 mg Prednisolone (30-60 mg) or IV Hydrocortisone 200 mg Nebulised Ipratropium Bromide (500 mcg) SC Terbutaline / IV Aminophylline (5mg/kg bolus over 20 mins.) Arrange for ambulance

Acute Asthma Emergency Department Management Initial Assessment History, Physical Examination, PEF or FEV1 Initial Therapy Bronchodilators , O2 if needed Good Response Incomplete/Poor Response Respiratory Failure Add Systemic Glucocorticosteroids Observe for at least 1 hour Good Response Poor Response If Stable, Discharge to Home Discharge Admit to Hospital Admit to ICU

Instructions / points on discharge Been on discharge medication for 24 hours Inhaler technique checked PEFR diurnal variability < 25% Oral + inhaled steroids / bronchodilators ? PEFR meter Follow-up appointment < 48 hrs with GP

‘Treat acute severe asthma at least 4 days before it occurs’ Thomas Petty

PREVENT ACUTE ATTACKS OF ASTHMA BY TAKING REGULAR INHALED CORTICOSTEROID TREATMENT