Asthma exacerbation resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Abdurahman Khalil, M.D. [2]

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Common Causes

• Viral infections
• Exposure to allergen
• Environmental pollutants
• Occupational irritants and sensitizers
• Medications:aspirin

Diagnosis

Characterize the symptoms:

Examine the patient: ❑ O2 saturation (pulse oximetry) ❑ Spirometry Arterial blood gas (ABG) (PaO2/PCO2 )

Classify the severity

Mild: Symptoms: ❑ Breathlessness while walking ❑ Speaks full sentences Signs: ❑ Tachypnea ❑ End expiratory wheezing ❑ Pulse < 100/min ❑ FEV1 ≥ 70% ❑ Pulse oximetry > 95 % ❑ ABG Normal

Moderate: Symptoms: ❑ Breathlessness at rest, prefers sitting ❑ Speaks phrases ❑ Usually agitated Signs: ❑ Tachypnea ❑ Using accessory muscles of respiration ❑ Expiratory wheezing ❑ Pulse 100-120/min ❑ Pulsus paradoxus may be present ❑ FEV1 40-69 % ❑ Pulse oximetry 90-95 % ❑ ABG: PaO2 ≥ 60 mm Hg PCO2 < 42 mm Hg

Severe: Symptoms: ❑ Breathlessness at rest, sits upright ❑ Speaks words ❑ Usually agitated Signs: ❑ Tachypnea ≥ 30/min ❑ Using accessory muscles of respiration ❑ Wheezing throughout inhalation and exhalation ❑ Pulse > 120/min ❑ Pulsus paradoxus present ❑ FEV1 < 40 % ❑ Pulse oximetry < 90 % ❑ ABG: PaO2 < 60 mm Hg PCO2 ≥ 42 mm Hg

Imminent respiratory arrest: Symptoms: ❑ Drowsy or confused Signs: ❑ Paradoxical thoracoabdominal movement ❑ Wheeze absent ❑ Bradycardia ❑ Pulsus paradoxus absent due to resp. fatigue ❑ FEV1 < 25 %

Management

Moderate exacerbation FEV1/PEF 40-60% Dyspnea with daily activities

Severe exacerbation FEV1/PEF<40% Dyspnea at rest

Respiratory arrest Intubation & mechanical ventilation 100%O2 SABA & Ipratropium IV corticosteroids

O2(target>90%sat) Inhaled SABA every 60mins PO corticosteroids

O2(>90%sat) SABA+Ipratropium continuous PO corticosteroids consider adjunct therapy

Good response FEV1/PEF>70% No distress Stable after 60 mins of Rx Normal H&P

Incomplete response FEV1/PEF 40-60% Mild-mod symptoms

Poor response FEV1/PEF<40% PCO2≥42 mm Hg Confusion and severe symptoms

Discharge

Admit to ward

Admit to ICU

Intubation &ventilation IV Corticosteroids SABA

• SABA:short acting beta agonist
• FEV1:forced expiratory volume for the for the first second
• PEF: Expiratory peak flow

Do's

• In severe exacerbation unresponsive to initial management, consider using IV Mg sulfate

Don'ts

Not recommended medications during hospitalization or emergency care settings

• Methylxanthine
• Antibiotics(except for comorbid conditions)
• Excessive hydration
• Mucolytics
• Chest physical therapy
• Sedation