St. Georges Hospital Emergency Setting

Asthma in Emergency setting St. Georges Hospital Emergency
Department
Cezar Darwiche FY1

Asthma
 Chronic inflammatory disease of the

airways

 Episodic cough, wheezing, dyspnea
 Type I hypersensitivity reaction (Ag cross

links IgE on pre-sensitized mast cells and basophils triggering release of vasoactive amines) Types
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Extrinsic
- Onset in childhood
-Triggered by inhaled allergen exposure:
Dust mites
Cockroaches
Cat antigen
Molds and pollens

Types
 Intrinsic

Early adulthood
• Triggered by viral infections, nonspecific irritants • Obesity risk factor
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Types
 Exercise-induced

Bronchospasm lasting 10-20 mins after exercise • Triggered by drying/ cooling of airways
• Requires prophylaxis
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Types
 Triad Asthma

Samter’s Syndrome
• Asthma
• Nasal polyps
• Aspirin or NSAID sensitivity
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Types
 Cough-variant asthma

May present with cough in absence of wheezing • One of the 3 most common causes of chronic cough (GERD, postnasal drip)
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Types
 Occupational asthma

“Monday morning” symptoms which abate during weekends
• Worse in the evening after work
• Commonly epoxy resins, plastics and rubber, metals, lab animals
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Refractory asthma
Chronic unremitting
Chronic exposure
B-blockers (even Timolol eye drops)
Aspirin containing drugs
GERD
Fungal infections
ABPA
Churg-strauss

Types
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Disorders that mimic asthma
Congestive heart failure
Mitral stenosis
Laryngeal tumors
Subglottic stenosis
Wegener’s
Vocal cord dysfunction
Left atrial enlargement with vagus impingement

Diagnosis
 History of wheezing with specific triggers
 Obstructive lung disease on PFTs that

normalize when asymptomatic
 DLCO normal between episodes
 Negative Methacoline challenge test effectively rules out asthma

Treatment
 Goals

Avoid symptoms
• Minimize use of short-acting bronchodilators • Prevent nocturnal awakening
• Minimize side-effects
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Treatment
 Four components

Monitor symptoms and pulmonary function
• Control environmental exposures
• Educate patient on trigger avoidance and treament • Drugs
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Emergency management
 Acute severe asthma

Peak flow (PEF) 33-50% best or predicted
• RR>25/min
• HR>110/min
• Inability to complete sentences in 1 breath
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Emergency management
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Life threatening asthma
Peak flow (PEF) <33% best or predicted
SaO2 <92% paO2 <60mmHg
PH <7.35
Silent chest
Cyanosis
Bradycardia, arrthymia, hypotension
Confusion, coma

Emergency management
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Management
Sit patient up (beware COPD exacerbation)
High flow O2 (100% non-rebreathing)
High dose nebulized B2 agonist (salbutamol
5mg or terbutaline 10mg)
WITH nebulized anticholinergic (Ipratropium
Bromide 0.5mg) for acute severe or life threatening Here given as Combivent

Emergency management
 Management

Corticosteroids
• Prednisolone 40-60mg PO
• Or Hydrocortisone 100mg IV
• Consider IV Aminophylline if poor response •

Emergency management
 Obtain CXR if:
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Suspected pneumothorax
Suspected consolidation
Life-threatening asthma
Failure to respond satisfactorily
Requirement for ventilation

Emergency management
 If improving

40-60% O2
• prednisolone 40-50mg/ 24hrs PO
• Nebulized salbutamol every 4hrs
• Monitor peak flow
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Emergency management
 If not improving after 15mins

Continue 100% O2
• Repeat steroids
• Salbutamol nebulizers every 15min or
10mg continuous per hour
• Ipratropium 0.5mg every 4-6hrs
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Emergency management
 If patient still not improving at &gt;30mins

Consider MgSO4 1.2-2g IV over 20mins
• Aminophylline IV
• Transfer to ICU for ventilation
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Emergency management
 Monitoring

Repeat PEF 15-30mins after treatment
• Pulse oximetry monitoring maintain SaO2
&gt;92%
• ABG within 2hrs if initial PaCO2 was normal/raised or initial PaO2 &lt;60mmHg
• Record PEF pre and post B2 agonist in hospital at least 4 times
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Emergency management
 Patient has improved

Stop Aminophylline over 12-24hrs
• Reduce nebulized Salbutamol and switch to inhaled B2 agonist
• Stop oral steroids and initiate inhaled
• Monitor PEF
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Emergency management
 Cardiac Arrest in Acute severe ashtma

Usually PEA
 Due to :
• Prolonged severe hypoxia
• Hypoxia related arrythmia
• Tension pneumothorax
• Acidosis and hyperkalemia
• Follow ACLS guidelines
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