Acute asthma exacerbation: Difference between revisions

No edit summary
 
(48 intermediate revisions by 14 users not shown)
Line 1: Line 1:
''For pediatrics patients see [[Asthma (peds)]]''
{{Adult top}} [[asthma (peds)]]
==Background==
==Background==
[[File:Bronchial anatomy with description.png|thumb| A - Alveoli
AS - Septum alveolare
BR - Bronchus respiratorius
BT - Bronchus terminalis
D - Mucous gland
DA - Ductus alveolaris
M - Musculus
N - Nervus
PA - Branch of Arteria pulm.
PV - Branch of Vena pulm.]]
[[File:Asthma attack-illustration NIH.jpg|thumb|Comparison of normal airway (B) to airway during asthma symptoms (C).]]
[[File:Asthma attack-illustration NIH.jpg|thumb|Comparison of normal airway (B) to airway during asthma symptoms (C).]]
*Quickly establish severity of current presentation and history of severe exacerbations (e.g. need for ICU, [[intubation]], etc)
[[File:Features of airway remodeling in asthma.jpg|thumb|Features of remodeling in asthma.]]
*Establish severity of current presentation based of vital signs, clinical presentation, and history of prior severe exacerbations (e.g. need for hospitalization, ICU admission, [[intubation]], etc.)
*Identify any treatable precipitant (e.g. [[pneumonia]], [[URI]], [[GERD]], exposure to irritants, [[aspirin]]/[[NSAIDs]])
*Identify any treatable precipitant (e.g. [[pneumonia]], [[URI]], [[GERD]], exposure to irritants, [[aspirin]]/[[NSAIDs]])
*''Status asthmaticus'' is a life-threatening form of asthma in which progressively worsening reactive airways are unresponsive to usual appropriate therapy leading to pulmonary insufficiency.
*''Status asthmaticus'' is a life-threatening form of asthma in which progressively worsening reactive airways are unresponsive to usual appropriate therapy leading to pulmonary insufficiency.
Line 18: Line 29:


==Differential Diagnosis==
==Differential Diagnosis==
{{Wheeze DDX}}
{{SOB DDX}}
{{SOB DDX}}


==Evaluation==
==Evaluation==
[[File:CXR3354 IM-1609-1001.png|thumb|[[CXR]] with hyperinflated lungs consistent with broncoconstriction.]]
===Workup===
*For uncomplicated exacerbations in patients with known asthma, [[CXR]] is ''not'' routinely indicated.<ref>Sakr M, et al. A Quality Improvement Initiative to Minimize Unnecessary Chest X-Ray Utilization in Pediatric Asthma Exacerbations. Pediatr Qual Saf. 2024 Apr 3;9(2):e721. doi: 10.1097/pq9.0000000000000721.</ref><ref>Sher et al. Int J Crit Care Emerg Med 2022, 8:142</ref>
*Consider [[CXR]] if:
**Asymmetric lung auscultation findings, after treatment with albuterol
**Poor response to medications/treatment, if history and exam are not consistent with asthma
**Worsening symptoms
**Unexplained [[fever]]
**[[Chest pain]]
===Diagnosis===
*Normally a clinical diagnosis
*Normally a clinical diagnosis
*[[ABG]] unlikely to add to clinical decision making unless pulse oximetry unavailable
*[[ABG]] unlikely to add to clinical decision making unless pulse oximetry unavailable
**However, a blood gas with a normal or elevated CO2 suggest impending respiratory failure (asthmatics typically hypocapneic during exacerbation)


===Consider [[CXR]] if===
===Classification===
*[[Fever]] >102.2°
{| class="wikitable"
*Worsening symptoms
|+ Clinical classification (≥ 12 years old)<ref>Yawn BP (September 2008). "Factors accounting for asthma variability: achieving optimal symptom control for individual patients" (PDF). Primary Care Respiratory Journal. 17 (3): 138–47. doi:10.3132/pcrj.2008.00004. PMC 6619889. PMID 18264646.</ref>
*Poor response to medications/treatment
|-
*1st wheeze
! scope="col" style="width:6em;" | Severity
*[[Chest pain]]
! scope="col" style="width:4em;" | Symptom frequency
! scope="col" style="width:4em;" | Night-time symptoms
! scope="col" style="width:4em;" | %FEV<sub>1</sub> of predicted
! scope="col" style="width:4em;" | FEV<sub>1</sub> variability
! scope="col" style="width:4em;" | SABA use
|-
! scope="row" | Intermittent
| ≤2/week
| ≤2/month
| ≥80%
| <20%
| ≤2 days/week
|-
! scope="row" | Mild persistent
| >2/week
| 3–4/month
| ≥80%
| 20–30%
| >2 days/week
|-
! scope="row" | Moderate persistent
| Daily
| >1/week
| 60–80%
| >30%
| daily
|-
! scope="row" | Severe persistent
| Continuously
| Frequent (7/week)
| <60%
| >30%
| ≥twice/day
|}


==Management==
==Management==
===[[Oxygen]] PRN===
*Titrate to an arterial oxygen saturation >90% (>95% in pregnant women and with coexistent heart disease)
===[[Albuterol]]===
===[[Albuterol]]===
''Favor continuous nebulization to decrease the chance of admission when compared to intermittent dosing''<ref>Camargo CA et al. Continuous versus intermittent beta- agonists for acute asthma. Cochrane Database Syst Rev. 2003;(4):CD001115. PMID: 14583926.</ref>
''Favor continuous nebulization to decrease the chance of admission when compared to intermittent dosing''<ref>Camargo CA et al. Continuous versus intermittent beta- agonists for acute asthma. Cochrane Database Syst Rev. 2003;(4):CD001115. PMID: 14583926.</ref>
Line 39: Line 99:
**If using intermitent nebs at home PTA, start on continuous
**If using intermitent nebs at home PTA, start on continuous
*MDI
*MDI
**4-8 puffs q20min up to 4h, then q1-4hr as needed
**6-12 puffs q20min up to 4h, then q1-4hr as needed
*Levalbuterol is pure R-enantiomer, whereas racemic albuterol as above is 50:50 mix of R and S albuterol
*Levalbuterol is pure R-enantiomer, whereas racemic albuterol as above is 50:50 mix of R and S albuterol
**Most clinical studies fail to show benefit over racemic albuterol<ref>Ralston ME, Euwema MS, Knecht KR, Ziolkowski TJ, Coakley TA, Cline SM. Comparison of levalbuterol and racemic albuterol combined with ipratropium bromide in acute pediatric asthma: a randomized controlled trial. J Emerg Med. 2005;29(1):29-35.</ref><ref>Qureshi F, Zaritsky A, Welch C, Meadows T, Burke BL.Clinical efficacy of racemic albuterol versus levalbuterol for the treatment of acute pediatric asthma. Ann Emerg Med. 2005;46(1):29-36.</ref>
**Most clinical studies fail to show benefit over racemic albuterol<ref>Ralston ME, Euwema MS, Knecht KR, Ziolkowski TJ, Coakley TA, Cline SM. Comparison of levalbuterol and racemic albuterol combined with ipratropium bromide in acute pediatric asthma: a randomized controlled trial. J Emerg Med. 2005;29(1):29-35.</ref><ref>Qureshi F, Zaritsky A, Welch C, Meadows T, Burke BL.Clinical efficacy of racemic albuterol versus levalbuterol for the treatment of acute pediatric asthma. Ann Emerg Med. 2005;46(1):29-36.</ref>
*Levalbuterol at 5x the cost, may not warrant the small benefits seen in some studies
*Levalbuterol at 5x the cost, may not warrant the small benefits seen in some studies
*In severe asthma exacerbation, be aware of lactic acidosis that develops due to pathology and the added lactic acidosis from albuterol
*In severe asthma exacerbation, be aware of lactic acidosis that develops due to pathology and the added lactic acidosis from [https://albuterolhfa.com albuterol],
**Manifests as worsening respiratory distress, tachypnea, compensatory increase in ventilation
**Manifests as worsening respiratory distress, tachypnea, compensatory increase in ventilation
**Ensure adequate intravascular volume, but carefully volume expand as acute asthma may increase ADH secretion<ref>Qureshi F. Management of children with acute asthma in the emergency department. Pediatr Emerg Care. 1999;15(3):206-214.</ref>
**Ensure adequate intravascular volume, but carefully volume expand as acute asthma may increase ADH secretion<ref>Qureshi F. Management of children with acute asthma in the emergency department. Pediatr Emerg Care. 1999;15(3):206-214.</ref>
*Rarely, clinically important [[hypokalemia]], alongside hyperglycemia and leukocytosis, may result from repeated beta agonists and sympathomimetics<ref>Leikin JB et al. Hypokalemia after pediatric albuterol overdose: a case series. Am J Emerg Med. 1994 Jan;12(1):64-6.</ref>
*Rarely, clinically important [[hypokalemia]], alongside hyperglycemia and leukocytosis, may result from repeated beta agonists and sympathomimetics<ref>Leikin JB et al. Hypokalemia after pediatric albuterol overdose: a case series. Am J Emerg Med. 1994 Jan;12(1):64-6.</ref>
===[[Ipratropium]]<ref>Goggin N, Macarthur C, Parkin PC. Randomized trial of the addition of ipratropium bromide to albuterol and corticosteroid therapy in children hospitalized because of an acute asthma exacerbation. Arch Pediatr Adolesc Med. 2001;155(12):1329-1334.</ref><ref>Rodrigo GJ, Rodrigo C. The role of anticholinergics in acute asthma treatment: an evidence-based evaluation. Chest. 2002;121(6):1977-1987.</ref>===
===[[Ipratropium]]<ref>Goggin N, Macarthur C, Parkin PC. Randomized trial of the addition of ipratropium bromide to albuterol and corticosteroid therapy in children hospitalized because of an acute asthma exacerbation. Arch Pediatr Adolesc Med. 2001;155(12):1329-1334.</ref><ref>Rodrigo GJ, Rodrigo C. The role of anticholinergics in acute asthma treatment: an evidence-based evaluation. Chest. 2002;121(6):1977-1987.</ref>===
*0.25-0.5mg q20min x2-3 doses
*0.25-0.5mg q20min x2-3 doses
*Only shown to the effective in the acute setting to reduce hospitalization rates and improve lung function
*Only shown to be effective in the acute setting to reduce hospitalization rates and improve lung function
*No benefit of adding to inpatient, hospitalized regimens
*No benefit of adding to inpatient, hospitalized regimens
===[[Steroids]]===
===[[Steroids]]===
Should be given in the first hour with effects to reduce admission and rate of relapses<ref name="Rowe">Rowe BH et al. Magnesium sulfate for treating exac- erbations of acute asthma in the emergency depart- ment. Cochrane Database Syst Rev. 2000;(2):CD001490. PMID: 10796650.</ref>
''Should be given in the first hour with effects to reduce admission and rate of relapses<ref name="Rowe">Rowe BH et al. Magnesium sulfate for treating exac- erbations of acute asthma in the emergency depart- ment. Cochrane Database Syst Rev. 2000;(2):CD001490. PMID: 10796650.</ref>'' Options include:
*[[Dexamethasone]]
*[[Dexamethasone]]
**As effective as [[prednisone]] especially in children <ref>Keeney, et al. Dexamethasone for Acute Asthma Exacerbations in Children: A Meta-analysis. Pediatrics. 2013-2273</ref>
**As effective as [[prednisone]] especially in children <ref>Keeney, et al. Dexamethasone for Acute Asthma Exacerbations in Children: A Meta-analysis. Pediatrics. 2013-2273</ref>
**Single dose dexamethasone may be equally effective to 5 days of [[prednisone]] in adults<ref>Rehrer MW et al. A randomized controlled noninferiority trial of single dose of oral dexamethasone versus 5 days of oral [[prednisone]] in acute adult asthma. Ann Emerg Med 2016 Apr 22.</ref>
**'''Single dose dexamethasone may be equally effective to 5 days of [[prednisone]] in adults'''<ref>Rehrer MW et al. A randomized controlled noninferiority trial of single dose of oral dexamethasone versus 5 days of oral [[prednisone]] in acute adult asthma. Ann Emerg Med 2016 Apr 22.</ref>
**0.6mg/kg IV or PO (max 16mg); 2nd dose 24hr later
**0.6mg/kg IV or PO (max 16mg); 2nd dose 24hr later may be an equally good option as single dose therapy <ref>Kratitz J et al. Two Days of Dexamethasone Versus 5 Days of Prednisone in the Treatment of Acute Asthma: A Randomized Controlled Trial. Ann Emerg Med. 2011 Aug;58(2):200-4. PMID: 2133409</ref>
*[[Prednisone]]
*[[Prednisone]]
**40-80mg/day in one or two divided doses x5d
**40-60mg /day x5d
*[[Methylprednisolone]]
*[[Methylprednisolone]]
**1mg/kg IV q 4–6hr
**1mg/kg IV q 4–6hr
Line 69: Line 129:


===[[Magnesium]]===
===[[Magnesium]]===
*25-75 mg/kg over 30 min (2-3 gm IV in most adults)
*25-75 mg/kg over 30 min (2-3 g IV in most adults)
*Duration of action approximately 20 min, beware of hypotension in rapid administration due to smooth muscle relaxation mechanism
*Duration of action approximately 20 min, beware of hypotension in rapid administration due to smooth muscle relaxation mechanism
*In patients with moderate to severe asthma there is a decreased rate of admission with an NNT of 2<ref name="Rowe"></ref>
*In patients with moderate to severe asthma there is a decreased rate of admission with an NNT of 2<ref name="Rowe"></ref>
 
*High-dose, prolonged magnesium may expedite discharge from the ED in non-infectious asthma in pediatric study<ref>Irazuzta J et al. High-Dose Magnesium Sulfate Infusion for Severe Asthma in the Emergency Department: Efficacy Study. Pediatric Critical Care Medicine. 17(2):e29–e33, FEBRUARY 2016.</ref>
===Leukotriene Modifiers===
**50 mg/kg/hr for 4 hours
*Zafirlukast (20 mg bid) and [[montelukast]] (10 mg/day)
**MAX 8,000 mg for 4 hours, monitor for cardiopulmonary complications
**No interventions or discontinuations of magnesium sulfate due to adverse events in the study
**NNT of 2-3, for hospital discharge before 24 hours


===Other Beta-Agonists===
===Other Beta-Agonists===
Line 84: Line 146:
*1:1000 0.01 mg/kg (max 0.5mg) subQ  or IM Q20min x3
*1:1000 0.01 mg/kg (max 0.5mg) subQ  or IM Q20min x3
*Nebulized racemic epinephrine 0.03 mL/kg (2.25% solution) diluted in 3-5 mL NS via jet nebulizer q3-4hr PRN shown to be as safe as nebulized albuterol<ref>Plint AC, Osmond MH, Klassen TP. The efficacy of nebulized racemic epinephrine in children with acute asthma: a randomized, double-blind trial. Acad Emerg Med. 2000;7(10):1097-1103.</ref>
*Nebulized racemic epinephrine 0.03 mL/kg (2.25% solution) diluted in 3-5 mL NS via jet nebulizer q3-4hr PRN shown to be as safe as nebulized albuterol<ref>Plint AC, Osmond MH, Klassen TP. The efficacy of nebulized racemic epinephrine in children with acute asthma: a randomized, double-blind trial. Acad Emerg Med. 2000;7(10):1097-1103.</ref>
*In severe, life-threatening asthma, IV epinephrine may be safe to consider, substantiated only by a case series of adults in 2003, however<ref>Smith D et al. Intravenous epinephrine in life-threatening asthma. Annals of Emerg Med. May 2003. Volume 41, Issue 5, Pages 706–711.</ref>
*Epinephrine infusion for adults at 5mcg/min (0.05mcg/kg/min for pediatrics) after requiring multiple epinephrine doses.


====[[Terbutaline]]====
====[[Terbutaline]]====
Line 92: Line 156:
**Elevated troponins q4hrs during infusion, more common in cTnI vs. cTnT, with EKG changes of ischemia should prompt re-evaluation for stopping infusion<ref>Kalyanaraman M et al. Serial cardiac troponin concentrations as marker of cardiac toxicity in children with status asthmaticus treated with intravenous terbutaline. Pediatr Emerg Care. 2011 Oct;27(10):933-6.</ref>
**Elevated troponins q4hrs during infusion, more common in cTnI vs. cTnT, with EKG changes of ischemia should prompt re-evaluation for stopping infusion<ref>Kalyanaraman M et al. Serial cardiac troponin concentrations as marker of cardiac toxicity in children with status asthmaticus treated with intravenous terbutaline. Pediatr Emerg Care. 2011 Oct;27(10):933-6.</ref>
*Some experts have nebulized IV form<ref>Lin YZ, Hsieh KH, Chang LF, Chu CY.Terbutaline nebulization and epinephrine injection in treating acute asthmatic children. Pediatr Allergy Immunol. 1996;7(2):95-99.</ref><ref>Rodrigo GJ, Nannini LJ. Comparison between nebulized adrenaline and beta2 agonists for the treatment of acute asthma. A meta-analysis of randomized trials. Am J Emerg Med. 2006;24(2):217-222.</ref>
*Some experts have nebulized IV form<ref>Lin YZ, Hsieh KH, Chang LF, Chu CY.Terbutaline nebulization and epinephrine injection in treating acute asthmatic children. Pediatr Allergy Immunol. 1996;7(2):95-99.</ref><ref>Rodrigo GJ, Nannini LJ. Comparison between nebulized adrenaline and beta2 agonists for the treatment of acute asthma. A meta-analysis of randomized trials. Am J Emerg Med. 2006;24(2):217-222.</ref>
**5 mg of IV form [[terbutaline]]
**[[Terbutaline]] 5 mg IV
**However, significantly higher cost than albuterol
**More expensive than albuterol
 
===[[Oxygen]] PRN===
*Titrate to an arterial oxygen saturation >90% (>95% in pregnant women and with coexistent heart disease)


===[[Non-invasive ventilation]]===
===[[Non-invasive ventilation]]===
*Consider as alternative to intubation
*Consider as alternative to intubation or pre-oxygenation prior to intubation
*Alleviates muscle fatigue which leads to larger tidal volumes
*Alleviates muscle fatigue which leads to larger tidal volumes
*May drive nebulized treatments deeper into airways
*May drive nebulized treatments deeper into airways
Line 106: Line 167:
**PEEP 0-3, only enough to match patient's auto-PEEP
**PEEP 0-3, only enough to match patient's auto-PEEP


===Heliox===
===[[Intubation]] and Invasive [[Ventilation]]===
*60 to 80% helium is blended with 20 to 40% oxygen
[[File:Breath stacking.jpg|thumbnail|A-B) Breath stacking and mounting lung volumes, C-D) Normal tracing]]
*Heliox improves non laminar flow and may increases the diffusion of carbon dioxide by improving ventilation<ref>Kass JE: Heliox redux. Chest 2003; 123:673.</ref>
*Relative indications include worsening hypercapnea, exhaustion, altered mental status, CO<sub>2</sub> narcosis without any specific number endpoint on blood gases, refractory hypoxemia, status asthmaticus
 
===[[Intubation]]===
*Relative indications include worsening hypercapnea, exhaustion, altered mental status, CO2 narcosis without any specific number endpoint on blood gases
*Consider induction with [[Ketamine]]
*Consider induction with [[Ketamine]]
**Provides bronchodilation and sedation however it does promote secretions  
**Provides bronchodilation and sedation however it does promote secretions  
Line 118: Line 176:
*Ventilation of asthmatic patients requires deep sedation
*Ventilation of asthmatic patients requires deep sedation
**[[Benzos]], [[propofol]], or [[ketamine]] (1mg/kg/hr)
**[[Benzos]], [[propofol]], or [[ketamine]] (1mg/kg/hr)
**Avoid paralysis if possible, given higher rates of complication<ref> Adnet F, Dhissi G, Borron SW, et al. Complication profiles f adult asthmatics requiring paralysis during mechanical ventilation. Intensive Care Med. 2001;27(11):1729-1736.</ref>
**Avoid long-term administration of neuromuscular blocking agents such as succinylcholine for prolonged periods in ICU (>12 hours), if possible, given higher rates of complication<ref> Adnet F, Dhissi G, Borron SW, et al. Complication profiles of adult asthmatics requiring paralysis during mechanical ventilation. Intensive Care Med. 2001;27(11):1729-1736.</ref>
**A large ET tube is preferred (>8.0 mm)
**A large ET tube is preferred (>8.0 mm)
*[[Ventilation settings]]
 
*'''Initial [[ventilation settings]] - severe asthma'''
**Assist-control ventilation
**Assist-control ventilation
**Resp rate
**Resp rate
***Start slow to avoid air-trapping
***Start slow to avoid air-trapping
***RR ~ 8-10 in adults
***RR ~ 8-10 in adults
**Make sure plateau pressure <30, with inspiratory hold
**'''Goal: obtaining a pH above 7.2 and plateau pressure below 30 cmH<sub>2</sub>O'''<ref>Stather DR, Stewart TE. Clinical review: Mechanical ventilation in severe asthma. Crit Care. 2005;9(6):581-587.</ref>
**If >30 must lower respiratory rate
**If Pplat >30 must lower respiratory rate
***If Pplat under 30 cannot be maintained, other causes of decreased respiratory system compliance must be considered (i.e. pneumothorax, misplaced endotracheal tube, pulmonary edema, etc.)
**May require "permissive hypoventilation"
**May require "permissive hypoventilation"
***Sacrifice MV for full exhalation
***Sacrifice MV for full exhalation
***Lower I:E ratio
***Lower I:E ratio
***Low peak pressure/avoidance of breath stacking more important than correcting CO2 <ref> Darioli, et al. Mechanical Controlled hypoventilation in status asthmaticus. Am Rev Respir Dis. 1984; 129 (3) 385-7 </ref>
***Low peak pressure/avoidance of breath stacking more important than correcting CO2 <ref> Darioli, et al. Mechanical Controlled hypoventilation in status asthmaticus. Am Rev Respir Dis. 1984; 129 (3) 385-7 </ref>
**Tidal volume 6-8cc/kg ideal wt
**Tidal volume 6-8mL/kg ideal wt
**PEEP 0
**PEEP 0-5 cmH<sub>2</sub>O
**Flow rate 80-100L/min
**Flow rate 80-100L/min
**Keep FiO2 minimum to achieve SpO2 > 90%
**Keep FiO2 minimum to achieve SpO2 > 90%
Line 139: Line 199:
**Most common cause of post-intubation hypotension<ref>Williams TJ, Tuxen DV, Scheinkestel CD, et al. Risk factors for morbidity in mechanically ventilated patients with acute severe asthma. Am Rev Respir Dis. 1992;146(3):607-615.</ref>
**Most common cause of post-intubation hypotension<ref>Williams TJ, Tuxen DV, Scheinkestel CD, et al. Risk factors for morbidity in mechanically ventilated patients with acute severe asthma. Am Rev Respir Dis. 1992;146(3):607-615.</ref>
**Check ventilator tracing
**Check ventilator tracing
[[File:Breath stacking.jpg|thumbnail|A-B) Breath stacking and mounting lung volumes, C-D) Normal tracing]]


===Asthma [[cardiac arrest|Arrest]]===
===Asthma [[cardiac arrest|Arrest]]===
Line 146: Line 205:
*Consider empiric bilateral [[chest tube]]s or rapid ultrasound to identify [[pneumothorax]]
*Consider empiric bilateral [[chest tube]]s or rapid ultrasound to identify [[pneumothorax]]
*[[IVF]] bolus
*[[IVF]] bolus
===[[Antibiotics]]===
*Administration of antibiotics only when physical exam or ancillary testing supportive of bacterial infection
*Antibiotics may be considered for select patients and may improve symptoms and peak expiratory flow, further understanding needed to identify which patients may be most likely to benefit <ref>Ganti L, Rosario J, Do Antibiotics Improve Outcomes in Patients With Acute Asthma Exacerbations? An of Emrg Med. 2019; 74(5) : 711–712.</ref>
===Heliox===
*60 to 80% helium is blended with 20 to 40% oxygen
*Heliox improves laminar flow and may increase the diffusion of carbon dioxide by improving ventilation<ref>Kass JE: Heliox redux. Chest 2003; 123:673.</ref>
===Leukotriene Modifiers===
*''Not'' indicated for acute treatment
*Zafirlukast (20 mg bid) and [[montelukast]] (10 mg/day)


==Outpatient Treatment==
==Outpatient Treatment==
New guidelines by Global Initiative for Asthma (GINA) 2019 endorse the use of an ICS-LABA combined product as both rescue and maintenance inhaler based off of a 2018 meta analysis <ref>Sobieraj, Diana M., et al. “Association of Inhaled Corticosteroids and Long-Acting β-Agonists as Controller and Quick Relief Therapy With Exacerbations and Symptom Control in Persistent Asthma.” Jama, vol. 319, no. 14, Oct. 2018, p. 1485., doi:10.1001/jama.2018.2769.</ref>
*GINA recommends budesonide or beclomethasone as the inhaled corticosteroid, and formoterol as the long acting beta agonist. The only U.S. formulation meeting this recommendation is [[Symbicort]] (budesonide-formoterol).
{|class="wikitable"
{|class="wikitable"
| align="center" style="background:*f0f0f0;"|'''Severity'''
| align="center" style="background:*f0f0f0;"|'''Severity'''
Line 173: Line 247:


==Disposition==
==Disposition==
*'''Discharge''' - if symptoms resolve
===Discharge===
*If symptoms resolve
**Often, patients will still have mild wheezing, but should have complete resolution of tachypnea, hypoxia, and work of breathing if being discharged
**Often, patients will still have mild wheezing, but should have complete resolution of tachypnea, hypoxia, and work of breathing if being discharged
**A short course of glucocorticoids decreases chance of relapse<ref>Chapman K. Effect of a short course of [[prednisone]] in the prevention of early relapse after the emergency room treatment of acute asthma. NEJM. 1991;324(12):788</ref> - [[prednisone]] in adults (40-60 mg/day for 5-10 days without tapering) or dexamethasone (0.6mg/kg) in children  
**A short course of glucocorticoids decreases chance of relapse<ref>Chapman K. Effect of a short course of [[prednisone]] in the prevention of early relapse after the emergency room treatment of acute asthma. NEJM. 1991;324(12):788</ref> - [[prednisone]] in adults (40-60 mg/day for 5-10 days without tapering) or dexamethasone (0.6mg/kg) in children  
*'''Admit''' - if symptoms persist or are severe
 
===Admit===
*If symptoms persist or are severe
*Classically disposition is based on peak flow measurements - however, these measurements are often not available in the ED
*Classically disposition is based on peak flow measurements - however, these measurements are often not available in the ED
**Predicted = (30 x age (yrs)) + 30
**Predicted = (30 x age (yrs)) + 30
Line 190: Line 267:


==External Links==
==External Links==
*[https://emcrit.org/ibcc/asthma/ Internet Book of Critical Care - Asthma]
*[http://emcrit.org/podcasts/severe-asthmatic/ EMCrit - The Severe Asthmatic]
*[http://emcrit.org/podcasts/severe-asthmatic/ EMCrit - The Severe Asthmatic]


Latest revision as of 20:47, 13 August 2025

This page is for adult patients. For pediatric patients, see: asthma (peds)

Background

A - Alveoli AS - Septum alveolare BR - Bronchus respiratorius BT - Bronchus terminalis D - Mucous gland DA - Ductus alveolaris M - Musculus N - Nervus PA - Branch of Arteria pulm. PV - Branch of Vena pulm.
Comparison of normal airway (B) to airway during asthma symptoms (C).
Features of remodeling in asthma.
  • Establish severity of current presentation based of vital signs, clinical presentation, and history of prior severe exacerbations (e.g. need for hospitalization, ICU admission, intubation, etc.)
  • Identify any treatable precipitant (e.g. pneumonia, URI, GERD, exposure to irritants, aspirin/NSAIDs)
  • Status asthmaticus is a life-threatening form of asthma in which progressively worsening reactive airways are unresponsive to usual appropriate therapy leading to pulmonary insufficiency.

Clinical Features

  • Dyspnea, wheezing, and cough (+/- sputum production)
  • Prolonged expiration
  • Accessory muscle use
  • Sign of impending ventilatory failure:
    • Paradoxical respiration (chest deflation and abdominal protrusion during inspiration)
    • Altered mental status
    • "Silent chest"
  • Low peak flows
  • Cyanosis is uncommon (respiratory alkalosis -> left shift of the oxyhemoglobin dissociation curve)

Differential Diagnosis

Bronchoconstriction

Acute dyspnea

Emergent

Non-Emergent

Evaluation

CXR with hyperinflated lungs consistent with broncoconstriction.

Workup

  • For uncomplicated exacerbations in patients with known asthma, CXR is not routinely indicated.[1][2]
  • Consider CXR if:
    • Asymmetric lung auscultation findings, after treatment with albuterol
    • Poor response to medications/treatment, if history and exam are not consistent with asthma
    • Worsening symptoms
    • Unexplained fever
    • Chest pain

Diagnosis

  • Normally a clinical diagnosis
  • ABG unlikely to add to clinical decision making unless pulse oximetry unavailable
    • However, a blood gas with a normal or elevated CO2 suggest impending respiratory failure (asthmatics typically hypocapneic during exacerbation)

Classification

Clinical classification (≥ 12 years old)[3]
Severity Symptom frequency Night-time symptoms %FEV1 of predicted FEV1 variability SABA use
Intermittent ≤2/week ≤2/month ≥80% <20% ≤2 days/week
Mild persistent >2/week 3–4/month ≥80% 20–30% >2 days/week
Moderate persistent Daily >1/week 60–80% >30% daily
Severe persistent Continuously Frequent (7/week) <60% >30% ≥twice/day

Management

Oxygen PRN

  • Titrate to an arterial oxygen saturation >90% (>95% in pregnant women and with coexistent heart disease)

Albuterol

Favor continuous nebulization to decrease the chance of admission when compared to intermittent dosing[4]

  • Nebulizer
    • Intermittent: 2.5-5mg q20min x3, then 2.5-10mg q1-4hr as needed OR
    • Continuous: 0.5mg/kg/hr (max 15mg/hr)[5]
    • If using intermitent nebs at home PTA, start on continuous
  • MDI
    • 6-12 puffs q20min up to 4h, then q1-4hr as needed
  • Levalbuterol is pure R-enantiomer, whereas racemic albuterol as above is 50:50 mix of R and S albuterol
    • Most clinical studies fail to show benefit over racemic albuterol[6][7]
  • Levalbuterol at 5x the cost, may not warrant the small benefits seen in some studies
  • In severe asthma exacerbation, be aware of lactic acidosis that develops due to pathology and the added lactic acidosis from albuterol,
    • Manifests as worsening respiratory distress, tachypnea, compensatory increase in ventilation
    • Ensure adequate intravascular volume, but carefully volume expand as acute asthma may increase ADH secretion[8]
  • Rarely, clinically important hypokalemia, alongside hyperglycemia and leukocytosis, may result from repeated beta agonists and sympathomimetics[9]

Ipratropium[10][11]

  • 0.25-0.5mg q20min x2-3 doses
  • Only shown to be effective in the acute setting to reduce hospitalization rates and improve lung function
  • No benefit of adding to inpatient, hospitalized regimens

Steroids

Should be given in the first hour with effects to reduce admission and rate of relapses[12] Options include:

  • Dexamethasone
    • As effective as prednisone especially in children [13]
    • Single dose dexamethasone may be equally effective to 5 days of prednisone in adults[14]
    • 0.6mg/kg IV or PO (max 16mg); 2nd dose 24hr later may be an equally good option as single dose therapy [15]
  • Prednisone
    • 40-60mg /day x5d
  • Methylprednisolone
    • 1mg/kg IV q 4–6hr
    • Only use IV if cannot tolerate PO since equal effectiveness between dosing routes[16]
    • Oral and IV steroids are safe during pregnancy (though technically Category C)
  • Inhaled corticosteroids may be considered as a rescue effort for severe asthma, given over a 90 min period[17][18]

Magnesium

  • 25-75 mg/kg over 30 min (2-3 g IV in most adults)
  • Duration of action approximately 20 min, beware of hypotension in rapid administration due to smooth muscle relaxation mechanism
  • In patients with moderate to severe asthma there is a decreased rate of admission with an NNT of 2[12]
  • High-dose, prolonged magnesium may expedite discharge from the ED in non-infectious asthma in pediatric study[19]
    • 50 mg/kg/hr for 4 hours
    • MAX 8,000 mg for 4 hours, monitor for cardiopulmonary complications
    • No interventions or discontinuations of magnesium sulfate due to adverse events in the study
    • NNT of 2-3, for hospital discharge before 24 hours

Other Beta-Agonists

  • Inhalation is preferred route of administration, but adequate drug delivery to small airways may be hampered in severe attacks
  • Terbutaline and epinephrine can be administered IM/IV/SubQ
  • Need to monitor for arrhythmias, tachycardia, hypertension, cardiac ischemia[20]

Epinephrine

  • 1:1000 0.01 mg/kg (max 0.5mg) subQ or IM Q20min x3
  • Nebulized racemic epinephrine 0.03 mL/kg (2.25% solution) diluted in 3-5 mL NS via jet nebulizer q3-4hr PRN shown to be as safe as nebulized albuterol[21]
  • In severe, life-threatening asthma, IV epinephrine may be safe to consider, substantiated only by a case series of adults in 2003, however[22]
  • Epinephrine infusion for adults at 5mcg/min (0.05mcg/kg/min for pediatrics) after requiring multiple epinephrine doses.

Terbutaline

  • Longer-acting beta2-agonist promoting bronchodilation
  • Caution in elderly/CHF with greater potential for cardiotoxicity
  • 0.25mg subQ/IM q20min x 3
    • Then followed by infusion at 1 µg/kg/min, titrated up by increments of 1 to max of 10 1 µg/kg/min
    • Elevated troponins q4hrs during infusion, more common in cTnI vs. cTnT, with EKG changes of ischemia should prompt re-evaluation for stopping infusion[23]
  • Some experts have nebulized IV form[24][25]

Non-invasive ventilation

  • Consider as alternative to intubation or pre-oxygenation prior to intubation
  • Alleviates muscle fatigue which leads to larger tidal volumes
  • May drive nebulized treatments deeper into airways
  • Maximize inspiratory support
    • Inspiratory pressure 8
    • PEEP 0-3, only enough to match patient's auto-PEEP

Intubation and Invasive Ventilation

A-B) Breath stacking and mounting lung volumes, C-D) Normal tracing
  • Relative indications include worsening hypercapnea, exhaustion, altered mental status, CO2 narcosis without any specific number endpoint on blood gases, refractory hypoxemia, status asthmaticus
  • Consider induction with Ketamine
    • Provides bronchodilation and sedation however it does promote secretions
    • Ketamine is the preferred induction agent for intubation in an asthmatic.
    • Dosing 1-2mg/kg
  • Ventilation of asthmatic patients requires deep sedation
    • Benzos, propofol, or ketamine (1mg/kg/hr)
    • Avoid long-term administration of neuromuscular blocking agents such as succinylcholine for prolonged periods in ICU (>12 hours), if possible, given higher rates of complication[26]
    • A large ET tube is preferred (>8.0 mm)
  • Initial ventilation settings - severe asthma
    • Assist-control ventilation
    • Resp rate
      • Start slow to avoid air-trapping
      • RR ~ 8-10 in adults
    • Goal: obtaining a pH above 7.2 and plateau pressure below 30 cmH2O[27]
    • If Pplat >30 must lower respiratory rate
      • If Pplat under 30 cannot be maintained, other causes of decreased respiratory system compliance must be considered (i.e. pneumothorax, misplaced endotracheal tube, pulmonary edema, etc.)
    • May require "permissive hypoventilation"
      • Sacrifice MV for full exhalation
      • Lower I:E ratio
      • Low peak pressure/avoidance of breath stacking more important than correcting CO2 [28]
    • Tidal volume 6-8mL/kg ideal wt
    • PEEP 0-5 cmH2O
    • Flow rate 80-100L/min
    • Keep FiO2 minimum to achieve SpO2 > 90%
  • Use bronchodilators even when intubated
  • Monitor for breath stacking (inspiratory holds, plateau pressures)
    • Most common cause of post-intubation hypotension[29]
    • Check ventilator tracing

Asthma Arrest

  • Disconnect ventilator
  • Decompress chest
  • Consider empiric bilateral chest tubes or rapid ultrasound to identify pneumothorax
  • IVF bolus

Antibiotics

  • Administration of antibiotics only when physical exam or ancillary testing supportive of bacterial infection
  • Antibiotics may be considered for select patients and may improve symptoms and peak expiratory flow, further understanding needed to identify which patients may be most likely to benefit [30]

Heliox

  • 60 to 80% helium is blended with 20 to 40% oxygen
  • Heliox improves laminar flow and may increase the diffusion of carbon dioxide by improving ventilation[31]

Leukotriene Modifiers

  • Not indicated for acute treatment
  • Zafirlukast (20 mg bid) and montelukast (10 mg/day)

Outpatient Treatment

New guidelines by Global Initiative for Asthma (GINA) 2019 endorse the use of an ICS-LABA combined product as both rescue and maintenance inhaler based off of a 2018 meta analysis [32]

  • GINA recommends budesonide or beclomethasone as the inhaled corticosteroid, and formoterol as the long acting beta agonist. The only U.S. formulation meeting this recommendation is Symbicort (budesonide-formoterol).
Severity Day Sx Night Sx Treatment (WHO 2008 Formulary)[33]
Mild intermittent, > 80% peak flow < 2/wk < 2/mo Albuterol MDI 100-200 mcg PRN QID
Mild persistent, > 80% peak flow >2/wk >2/mo Albuterol MDI 100-200 mcg PRN QID AND

Beclometasone 100-250 mcg bid

Moderate persistent, 60-80% peak flow Daily with exacerbations weekly > 1/wk Albuterol MDI 100-200 mcg PRN QID AND

Beclometasone 100-500 mcg BID AND

Salmeterol inhaled 50 mcg bid

Severe persistent, < 60% peak flow Continuous daily Frequent Albuterol MDI 100-200 mcg PRN QID AND

Beclometasone 1mg BID (high dose) AND

Salmeterol inhaled 50 mcg BID AND (if needed)

theophylline, leukotriene antagonist, or PO prednisolone with taper

Disposition

Discharge

  • If symptoms resolve
    • Often, patients will still have mild wheezing, but should have complete resolution of tachypnea, hypoxia, and work of breathing if being discharged
    • A short course of glucocorticoids decreases chance of relapse[34] - prednisone in adults (40-60 mg/day for 5-10 days without tapering) or dexamethasone (0.6mg/kg) in children

Admit

  • If symptoms persist or are severe
  • Classically disposition is based on peak flow measurements - however, these measurements are often not available in the ED
    • Predicted = (30 x age (yrs)) + 30
    • PEF >70% predicted → high likelihood of successful discharge
    • PEF <40% predicted → should be admitted

See Also

External Links

References

  1. ↑ Sakr M, et al. A Quality Improvement Initiative to Minimize Unnecessary Chest X-Ray Utilization in Pediatric Asthma Exacerbations. Pediatr Qual Saf. 2024 Apr 3;9(2):e721. doi: 10.1097/pq9.0000000000000721.
  2. ↑ Sher et al. Int J Crit Care Emerg Med 2022, 8:142
  3. ↑ Yawn BP (September 2008). "Factors accounting for asthma variability: achieving optimal symptom control for individual patients" (PDF). Primary Care Respiratory Journal. 17 (3): 138–47. doi:10.3132/pcrj.2008.00004. PMC 6619889. PMID 18264646.
  4. ↑ Camargo CA et al. Continuous versus intermittent beta- agonists for acute asthma. Cochrane Database Syst Rev. 2003;(4):CD001115. PMID: 14583926.
  5. ↑ National Asthma Education and Prevention Program (NAEPP), “Expert Panel Report 3 (EPR-3): Guidelines for the Diagnosis and Management of Asthma,” Clinical Practice Guidelines, National Institutes of Health, National Heart, Lung, and Blood Institute, NIH Publication No. 08-4051, prepublication 2007; available at http://www.nhlbi.nih.gov/guidelines/asthma/asthgdln.htm.
  6. ↑ Ralston ME, Euwema MS, Knecht KR, Ziolkowski TJ, Coakley TA, Cline SM. Comparison of levalbuterol and racemic albuterol combined with ipratropium bromide in acute pediatric asthma: a randomized controlled trial. J Emerg Med. 2005;29(1):29-35.
  7. ↑ Qureshi F, Zaritsky A, Welch C, Meadows T, Burke BL.Clinical efficacy of racemic albuterol versus levalbuterol for the treatment of acute pediatric asthma. Ann Emerg Med. 2005;46(1):29-36.
  8. ↑ Qureshi F. Management of children with acute asthma in the emergency department. Pediatr Emerg Care. 1999;15(3):206-214.
  9. ↑ Leikin JB et al. Hypokalemia after pediatric albuterol overdose: a case series. Am J Emerg Med. 1994 Jan;12(1):64-6.
  10. ↑ Goggin N, Macarthur C, Parkin PC. Randomized trial of the addition of ipratropium bromide to albuterol and corticosteroid therapy in children hospitalized because of an acute asthma exacerbation. Arch Pediatr Adolesc Med. 2001;155(12):1329-1334.
  11. ↑ Rodrigo GJ, Rodrigo C. The role of anticholinergics in acute asthma treatment: an evidence-based evaluation. Chest. 2002;121(6):1977-1987.
  12. ↑ 12.0 12.1 Rowe BH et al. Magnesium sulfate for treating exac- erbations of acute asthma in the emergency depart- ment. Cochrane Database Syst Rev. 2000;(2):CD001490. PMID: 10796650.
  13. ↑ Keeney, et al. Dexamethasone for Acute Asthma Exacerbations in Children: A Meta-analysis. Pediatrics. 2013-2273
  14. ↑ Rehrer MW et al. A randomized controlled noninferiority trial of single dose of oral dexamethasone versus 5 days of oral prednisone in acute adult asthma. Ann Emerg Med 2016 Apr 22.
  15. ↑ Kratitz J et al. Two Days of Dexamethasone Versus 5 Days of Prednisone in the Treatment of Acute Asthma: A Randomized Controlled Trial. Ann Emerg Med. 2011 Aug;58(2):200-4. PMID: 2133409
  16. ↑ Rowe BH, Keller JL, Oxman AD. Effectiveness of steroid therapy in acute exacerbations of asthma: a meta-analysis. Am J Emerg Med. Jul 1992;10(4):301-10
  17. ↑ Rodrigo GJ. Inhaled Corticosteroids as Rescue Medication in Acute Severe Asthma. Expert Rev Clin Immunol. 2008;4(6):723-729.
  18. ↑ Volovitz B. Inhaled budesonide in the management of acute worsenings and exacerbations of asthma: a review of the evidence. Respir Med. 2007 Apr;101(4):685-95.
  19. ↑ Irazuzta J et al. High-Dose Magnesium Sulfate Infusion for Severe Asthma in the Emergency Department: Efficacy Study. Pediatric Critical Care Medicine. 17(2):e29–e33, FEBRUARY 2016.
  20. ↑ Scarfone RJ, Friedlaender EY.beta2-Agonists in acute asthma: the evolving state of the art. Pediatr Emerg Care. 2002;18(6):442-427.
  21. ↑ Plint AC, Osmond MH, Klassen TP. The efficacy of nebulized racemic epinephrine in children with acute asthma: a randomized, double-blind trial. Acad Emerg Med. 2000;7(10):1097-1103.
  22. ↑ Smith D et al. Intravenous epinephrine in life-threatening asthma. Annals of Emerg Med. May 2003. Volume 41, Issue 5, Pages 706–711.
  23. ↑ Kalyanaraman M et al. Serial cardiac troponin concentrations as marker of cardiac toxicity in children with status asthmaticus treated with intravenous terbutaline. Pediatr Emerg Care. 2011 Oct;27(10):933-6.
  24. ↑ Lin YZ, Hsieh KH, Chang LF, Chu CY.Terbutaline nebulization and epinephrine injection in treating acute asthmatic children. Pediatr Allergy Immunol. 1996;7(2):95-99.
  25. ↑ Rodrigo GJ, Nannini LJ. Comparison between nebulized adrenaline and beta2 agonists for the treatment of acute asthma. A meta-analysis of randomized trials. Am J Emerg Med. 2006;24(2):217-222.
  26. ↑ Adnet F, Dhissi G, Borron SW, et al. Complication profiles of adult asthmatics requiring paralysis during mechanical ventilation. Intensive Care Med. 2001;27(11):1729-1736.
  27. ↑ Stather DR, Stewart TE. Clinical review: Mechanical ventilation in severe asthma. Crit Care. 2005;9(6):581-587.
  28. ↑ Darioli, et al. Mechanical Controlled hypoventilation in status asthmaticus. Am Rev Respir Dis. 1984; 129 (3) 385-7
  29. ↑ Williams TJ, Tuxen DV, Scheinkestel CD, et al. Risk factors for morbidity in mechanically ventilated patients with acute severe asthma. Am Rev Respir Dis. 1992;146(3):607-615.
  30. ↑ Ganti L, Rosario J, Do Antibiotics Improve Outcomes in Patients With Acute Asthma Exacerbations? An of Emrg Med. 2019; 74(5) : 711–712.
  31. ↑ Kass JE: Heliox redux. Chest 2003; 123:673.
  32. ↑ Sobieraj, Diana M., et al. “Association of Inhaled Corticosteroids and Long-Acting β-Agonists as Controller and Quick Relief Therapy With Exacerbations and Symptom Control in Persistent Asthma.” Jama, vol. 319, no. 14, Oct. 2018, p. 1485., doi:10.1001/jama.2018.2769.
  33. ↑ Stuart MC et al. WHO Model Formulary 2008. http://www.who.int/selection_medicines/list/WMF2008.pdf.
  34. ↑ Chapman K. Effect of a short course of prednisone in the prevention of early relapse after the emergency room treatment of acute asthma. NEJM. 1991;324(12):788
Retrieved from "https://www.wikem.org/w/index.php?title=Acute_asthma_exacerbation&oldid=377663"