Acute Sever Asthma introduction and management.ppt
- 1. Acute Severe Asthma Dr. Abdu Alhmadi
- 2. Definition of severe asthma • Patients who need high dose inhaled CCS and long-acting ß2 agonists and: – are still uncontrolled – experience frequent acute exacerbations – and/or often require emergency treatment and/or hospitalization
- 3. Bronchial Asthma Spirometric abnormalities Central airway narrowing Bronchoconstriction Gas exchange abnormalities Distal airway narrowing Airway Inflammation Treatments must be directed towards these two components: Smooth muscle spasm Inflammation, edema, plugs
- 4. Features of a severe asthma exacerbation One or more present: • Use of accessory muscles of respiration • Pulsus paradoxicus >25 mm Hg • Pulse > 110 BPM • Inability to speak sentences • Respiratory rate >25 - 30 breaths/min • PEFR or FEV1 < 50% predicted • SaO2 <91- 92%
- 5. Risk factors for fatal or near-fatal asthma attacks • Previous episode of near-fatal asthma • Multiple prior ER visits or hospitalizations • Poor compliance with medical treatments • Allergy • Recent use of oral corticosteroid (OCS) • Inadequate therapy: – Excessive use of β-agonists – No inhaled corticosteroid (ICS) – Concomitant β-blockers Y
- 6. Physical findings in severe asthma exacerbations • Tachypnea. . Hypotention. • Bradycardia or arrythmias. • Tachycardia. • Wheeze, or silent chest • Hyperinflation • Accessory muscle use • Pulsus paradoxicus • Diaphoresis (profuse sweating) • Cyanosis • Sweating • Obtundation (altered mental state)
- 7. Causes of asthma exacerbations • Lower or upper respiratory infections • Cessation or reduction of medication • Concomitant medication, e.g. β-blocker • Allergen or pollutant exposure
- 8. Differential diagnosis • COPD • Bronchitis • Bronchiectasis • Endobronchial diseases • Foreign bodies • Extra- or intra-thoracic tracheal obstruction • Carcinoid syndrome • .vocal cord ddysfunction • Vaso-vagal reaction • Cardiogenic pulmonary edema • Non-cardiogenic pulmonary edema • Pneumonia • Pulmonary emboli • Chemical pneumonitis • Hyperventilation syndrome
- 9. Stages of asthma exacerbations Stage 1: Symptoms • Somewhat short of breath • Can lie down and sleep through the night • Cannot perform full physical activities without shortness of breath Signs • Some wheezes on examination • Respiratory rate, 18 • Pulse 100 • Peak flows and spirometry reduced by 10%
- 10. Stages of asthma exacerbations Stage 2: Symptoms • Less able to do physical activity due to shortness of breath • Dyspnea on walking stairs • May wake up at night short of breath • Uncomfortable on lying down • Some use of accessory muscles of respiration Signs • Wheezing • Respiratory rate 19-20 • Pulse 111 • Peak flows and spirometry reduced by 20+%
- 11. Stages of asthma exacerbations Stage 3: Symptoms • Unable to perform physical activity without shortness of breath • Cannot lie down without dyspnea • Speaks in short sentences • Using accessory muscles Signs • Wheezing • Respiratory rate 20-25 • Pulse 120 • Peak flows and spirometry reduced by 30+%
- 12. Stages of asthma exacerbations Stage 4: Symptoms • Sitting bent forward • Unable to ambulate without shortness of breath • Single word sentences • Mentally-oriented and alert • Use of accessory muscles Signs • Wheezing less pronounced than anticipated • Respiratory rate 25-30 • Pulse 125+ • Peak flows and spirometry reduced by 40+% • SaO2 91- 92%
- 13. Stages of asthma exacerbations Stage 5: Symptoms • Reduced consciousness • Dyspnea • Silent chest – no wheezing Signs • Fast, superficial respiration • Respiratory rate >30 • Unable to perform pek flows or spirometry • Pulse 130 - 150+ • SAO2 <90
- 14. Severity of asthma as graded by % predicted FEV1 FEV% predicted Severity • 70 - 100 Mild • 60 - 69 Moderate • 50 - 59 Moderately severe • 35 - 49 Severe • < 35 Very severe: (life-threatening)
- 15. Acute severe asthma - clinical assessment • Respiratory frequency: (count) – Speech: sentences, single words • Auxiliary respiratory muscle use • Posture: sitting, can patient lie down? • Airway patency: rhonchi, silent chest (PEF) • Respiration: cyanosis (SaO2, blood gases) • General appearance, effort of breathing: activity level (pulse rate)
- 16. Acute severe asthma - monitoring • Clinical condition • PEF or FEV1 • PaO2 and PaCO2
- 17. Acute severe asthma Admission and close monitoring in hospital unit: • Clinical stage 4 • PEF or FEV1 < 30% of personal best (if unknown < 30% predicted) • PaCO2 > 6 kPa • PaO2 < 8 kPa • Poor response to initial treatment
- 18. Acute severe asthma treatment Oxygen by nasal cannulae or mask Inhaled broncodilator should be administered at regular Intervals: Nebulised ß2-agonist combined with anticholinergic each 20 mins in the first hour, then hourly as necessary Systemic steroid should be utilised: Oral (50-75mg prednisolone) or i.v. corticosteroid (80 mg Methylprednisolone); repeat after 12 hours; over the following days 40 mg prednisolone or equivalent is usually maintained Start inhaled high dose steroid as soon as possible
- 19. Acute severe asthma treatment Dangerous, or at least ineffective Dangerous:Sedation Ineffective: Mucolytics Physiotherapy Antihistamines
- 20. Acute severe asthma treatment Consider: Infusion of Beta-2-agonist Infusion of theophylline Antibiotics – not all acute asthma exacerbations require antibiotics Fluids
- 21. Acute severe asthma – treatment options Standard treatment: Oxygen Inhaled beta-2-agonist +/- anticholinergic Systemic corticosteroid Additional options: Systemic beta-2-agonist and/or theophylline, antibiotics, fluids Nonstandard treatment: Antileukotrienes; Magnesium sulphate; Heliox; . Extreme intervention: Intubation and controlled hypoventilation/other strategy Anesthesia-sedation; Bronchial lavage
- 22. Treatment of asthma exacerbations oral corticosteroids • Oral corticosteroids are the most powerful medications available to reduce airway inflammation • Use until attack has completely abated: – PEFR and FEV1 at baseline levels – Symptoms gone • Taper to QOD and determine if patient can remain well if corticosteroids are withdrawn completely
- 23. Oxygen • Oxygen must be considered as a drug in a situation of acute asthma • reducing hypoxic pulmonary vasoconstriction • ventilation-perfusion mismatch
- 24. Inhaled B2 agonist • There is evidence suggesting that continuous administration of nebulised β2-agonists may have a better and prolonged bronchodilatory effect compared to intermittent therapy • β2-agonist should be administered until development of significant side effects, a strategy requiring close monitoring
- 25. • Nebulizes Salbuterol, 2.5 mg (diluted to 4 mL), in uncomplicated asthma, double the concentration in severe cases • Undiluted drug for severe status asthmaticus.
- 26. Ipratropium bromide • The combination of nebulised IB with a nebulised ß2 agonist has been shown to result in greater bronchodilatation than a ß2 agonist alone. • The most severely affected patients benefit the most, and IB should be considered in combination with inhaled ß2 agonists : • More severe forms of asthma • Early in the acute attack, • If there is an incomplete response to inhaled ß2 agonists on their own • May be repeated every 20 min for the first hour and every four hours thereafter
- 27. IV Salbutamol • The use of IV salbutamol (15 mcg/kg as a once-off dose) in the early management of acute severe asthma has been shown to reduce the duration of the exacerbation and hasten the discharge from hospital . • In the intensive care unit IV salbutamol by continuous infusion is effective and probably safer than aminophylline. • Side effect • Cardiovascular in nature • hypokalemia
- 28. IV aminophelline • The positive effect from theophylline infusion on acute asthma is well documented, as are the potential for side effects and severe or even fatal complications • May be used in cases of near fatal or life threatening asthma in the intensive care unit. • Inhaled drugs may have limited effect in nearly complete airway obstruction and have practical limitations in ventilated patient. a 6-mg/kg aminophylline load followed by a 1-mg/kg/h infusion.
- 29. Adrenalline • Adrenaline 0.01 ml/kg of a 1:1000 solution administered subcutaneously may be used in patients who are moribund on presentati on to the ED, or where inhaled therapy is n ot available.
- 30. Magnesium sulphate • Magnesium cause smooth muscle relaxation secondary to inhibition of calcium uptake. • A single dose of IV magnesium sulphate has been shown to be safe a nd effective in those patients with acute severe asthma who have had a poor response to initial therapy. • The response to magnesium appears to be best in patients who pres ent with very severe illness. • The dose is 25 - 50 mg/kg/dose (maximum 2 g) by slow IV infusion.
- 31. • Treat the condition symptomatically • Determine what caused the exacerbation: – inhalant allergen – food allergen – drug reaction (ASA, vaccination, etc) – infection – worsening of a chronic condition: - poor therapy compliance - treatment needs adjustment
- 32. Prevention of relapse and recurrence of asthma exacerbation - definition Relapse: Reappearance of asthma symptoms that require unscheduled care within 3 weeks of an asthma exacerbation Recurrence: Reappearance of asthma symptoms that require unscheduled care more than 3 weeks after the asthma exacerbation
- 33. Prevention of relapse and recurrence of asthma exacerbation Patients treated for an asthma exacerbation are at risk for subsequent severe attacks: (unscheduled doctor visits, Emergency Department visits, hospitalization, asthma death) Proper asthma care can reduce this risk: a) Pharmacological intervention with ICS b) Patient education – knowledge and skills c) Self management plans and follow up
- 34. THANKS
Editor's Notes
- #2: Patients at high risk of serious asthma-related morbidity and mortality generally have severe disease and remain symptomatic despite high-dose inhaled corticosteroids. These patients experience frequent acute exacerbations of their underlying disease, and often require emergency treatment and/or hospitalization. As such, their management accounts for up to half of the total direct and indirect costs of asthma. New treatment options that would permit improved disease control in these high-risk patients, thereby minimizing the incidence and frequency of serious asthma exacerbations, would have significant clinical and socioeconomic implications. [next slide]
- #8: Embolus - singular, emboli - plural - need only mention it once
- #9: Stages of asthma exacerbations will be illustrated, with separate slides for stages 1 through 5
- #19: I think divide these into
- #20: I think need clarifying statement next to antibiotic - not all acute exacerbations need these!