Version May 2024
| Clinical danger signs |
| Use of accessory muscles of respiration; brief, fragmented speech; inability to lie supine; profound diaphoresis; agitation; severe symptoms that fail to improve with initial emergency treatment |
| Life-threatening airway obstruction can still occur when these signs are NOT present |
| Signs of imminent respiratory arrest: cyanosis, inability to maintain respiratory effort, and depressed mental status |
| Assessment |
| Measurement of expiratory airflow (peak expiratory flow rate or PEFR) is the best measure of severity; PEFR <40% predicted (or <200 L/minute in most adults) indicates severe obstruction; patients in severe distress are often unable to perform peak flow tests |
| Severe hypoxemia (eg, SpO2 ≤95% despite high flow O2 treatment by nonrebreather mask) portends imminent respiratory arrest or possibly severe complication (eg, pneumothorax); continuous pulse oximetry monitoring should be performed |
| Patients in extremis should be managed clinically without waiting for arterial blood gases (ABGs). ABGs can aid assessment of hypercapnia or impending respiratory failure: hypercapnia usually does not occur unless PEF is <25% of normal (generally <100 to 150 L/min). |
| Chest radiograph is generally unhelpful; obtain if complications suspected (eg, pneumonia, pneumothorax), diagnosis is in doubt, or patient is high-risk (eg, IV drug abuser, immunosuppressed, chronic pulmonary disease, heart failure) |
| Standard treatments |
| Inhaled beta agonist: give albuterol 2.5 to 5 mg by nebulization every 20 minutes for three doses, then 2.5 to 5 mg every one to four hours as needed, or give 4 to 8 puffs by metered dose inhaler (MDI) with spacer every 20 minutes for three doses, then every one to four hours as needed. Alternatively, for severe exacerbations, 10 to 15 mg can be administered by continuous nebulization over one hour. |
| Oxygen: give sufficient oxygen to maintain SpO2 ≥92% (>95% in pregnancy) |
| IV: establish intravenous access; give IV boluses of isotonic saline if patient is dehydrated due to reduced intake and prolonged episode |
| Ipratropium bromide: give 500 mcg by nebulization every 20 minutes for 3 doses OR 4 to 8 puffs by MDI with spacer every 20 minutes for 3 doses; then may administer additional doses hourly as needed for up to 3 hours |
| Systemic glucocorticoids: for patients with impending respiratory failure, give methylprednisolone 60 to 125 mg IV. For the majority of less severe asthma exacerbations, give prednisone 40 to 60 mg orally; alternatives include: dexamethasone 6 to 10 mg IV or hydrocortisone 150 to 200 mg IV; glucocorticoids may be given IM or orally if IV access is unavailable. |
| Magnesium sulfate: give 2 g (8 mmol) IV over 20 minutes for life-threatening exacerbations and severe exacerbations that are unimproved after one hour of intensive bronchodilator therapy |
| Additional treatments |
| Epinephrine: for patients suspected of having an anaphylactic reaction or unable to use inhaled bronchodilators for severe asthma exacerbation, give epinephrine 0.3 to 0.5 mg IM (eg, 0.3 to 0.5 mL of 1 mg/mL [may be labeled 1:1000] solution) into the mid-outer thigh (vastus lateralis muscle); if needed can repeat every 20 minutes for up to 3 doses; give epinephrine OR terbutaline but not both |
| Terbutaline: may give 0.25 mg by SC injection every 20 minutes times 3 doses for patients unable to use inhaled bronchodilators; give terbutaline OR epinephrine but not both |
| Endotracheal intubation and ventilation |
| The decision to intubate during the first few minutes of a severe asthma attack is clinical. Slowing of the respiratory rate, depressed mental status, inability to maintain respiratory effort, or severe hypoxemia suggests the patient requires intubation. In the absence of anticipated intubation difficulty, rapid sequence intubation is preferred. Nasal intubation is not recommended. |
| The goal of mechanical ventilation is to maintain adequate oxygenation and ventilation while minimizing elevations in airway pressures. This is accomplished by using low tidal volumes (6 to 8 mL/kg), and low respiratory rates (10 to 12/minute). In some patients, elevations in PaCO2 must be tolerated to avoid barotrauma (ie, permissive hypercapnia).* |
آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟
