Approach to Dyspnea

Indiana University Department of Emergency Medicine

MS IV Lecture Series

General Approach

H&P DDx Tests Treatment

General Approach

Assess severity

Immediate interventions

Further history

Additional treatment

General Approach• Intervention may be needed immediately,

before evaluation is complete Intubation CPAP/Bi-PAP Nebs Chest tube Others

Assessing the severity:

What are signs of respiratory distress?

Assessing the severity:

• Vitals (tachypnea, abnormal HR)• Pulse oximetry• Position

Supine: reassuring; Tripod: worrisome• Speech – words per sentence• Retractions, accessory muscle use• Altered LOC, agitation• Diaphoresis

Respiratory Distress

Immediate intervention

1. Intubate if not protecting airway

Respiratory Distress

Immediate intervention

2. Treat presumed etiology – educated guess based on:

• Brief history• Known PMHx (a 20 yo with hx asthma is unlikely

to be presenting with acute CHF)• Chest exam• Portable CXR

Respiratory Distress

Immediate intervention

3. Gather more data as the pt stabilizes Refine treatment

History

Onset• Sudden onset

consider PE, pneumothorax

History

Associated chest pain?• Consider MI, PE, PTX, Pneumonia

History

Orthopnea or PND?• Consider CHF

History

Systemic symptoms? • Fever• Weight loss• Night sweats• Anxiety

History

Past medical history• COPD• CHF• Asthma• Cancer• HIV• PE risk factors

Physical Examination

• Respiratory rate (check it yourself)

• Signs of respiratory distress

• Auscultation

Physical Examination

Beware: all that wheezes is not asthma• Pulmonary edema (“cardiac wheezing”)• Foreign body• Pulmonary infection• PE• Anaphylaxis• Many others

Ancillary TestingCXR Helpful for most patients with acute SOB• Infiltrates• Effusions• Pneumothorax• Pulmonary edema• Foreign bodies• Masses

Ancillary TestingCXR Helpful for most patients with acute SOB• Infiltrates• Effusions• Pneumothorax• Pulmonary edema• Foreign bodies• Masses

Ancillary Testing

CXR is not necessary in asthma exacerbations unless complication or alternative dx suspected

Ancillary Testing

Other tests as dictated by the H&P:

• Cardiac etiology suspected EKG Cardiac markers BNP (CHF)

Ancillary Testing

Other tests as dictated by the H&P:

• D-dimer or CT if PE suspected

Ancillary Testing

Other tests as dictated by the H&P:

• Non-cardiopulmonary causes of dyspnea CBC (anemia) Metabolic Panel (metabolic acidosis)

Ancillary Testing

Other tests as dictated by the H&P:

• ABG usually not helpful

Arterial Blood Gas• Does it help determine the etiology of SOB?

Arterial Blood Gas• Critical Care. 2011; 15(3)• Retrospective analysis of 530 ED patients with

acute dyspnea• Results:

“ABG analysis parameters were neither useful to distinguish between patients with pulmonary disorders and other causes of dyspnea nor to identify specific disorders responsible for dyspnea”

Case #1• 15 yo male presents with severe SOB

gradually worsening all day, associated with non-productive cough but no chest pain.

• PMHx: Asthma• Meds: Albuterol MDI (took 6 doses today)

Case #1• Sitting up in bed, visibly dyspneic, diaphoretic• VS: 1001F 110 28 146/86 95% RA• Normal mental status• Speaking in 3-4 word sentences• Chest: + retractions, diffuse wheezing

What treatments do you want to start?

Treatment of Asthma Exacerbations

Beta-agonists are the cornerstone• Albuterol, others• Usually given via nebulizer in ED

Intermittent dosing, usually 5mg/dose Continuous neb

Somewhat more efficacious in severe asthma

Cochrane Database Syst Rev. 2003;(4):CD001115.

Treatment of Asthma Exacerbations

What about Levalbuterol (Xopenex)?

• R-enantiomer of albuterol• Purported to have fewer side effects

Not consistently demonstrated in clinical studies• Albuterol generally well tolerated• Levalbuterol is expensive

Treatment of Asthma: Steroids• Corticosteroids treat the underlying airway

inflammation• Improvement is seen within hours

Give first dose in the ED• Demonstrated to decrease hospital admissions

• NNT=8 for moderate/severe exacerbations

Cochrane Database Syst Rev.2001;(1):CD002178

Treatment of Asthma: Steroids

• Systemic steroids are better than inhaled for acute exacerbations

• PO appears to be equivalent to IV

Treatment of Asthma: Steroids• Discharge patient with a 5-7 day “burst”

• Prevents relapses• No taper necessary• Prednisone 40-60 mg/day

Treatment of Asthma: Anticholinergics• Ipratropium (atrovent)

• MDI or Neb • Decrease airway secretions and smooth

muscle tone• Slower onset and less effective

bronchodilation than the b2-agonists• Minimal absorption; good side effect profile

• Small benefit when used with b2-agonists over using b2-agonists alone• More effective in severe asthma

• Usual dose: 0.5mg neb x 3• Mix with albuterol

Treatment of Asthma: Anticholinergics

Asthma: other therapies

Methylxanthines (theophylline)• Narrow therapeutic index• No clear benefit over b2-agonists alone• No longer used

Asthma: other therapies

• Antibiotics: not helpful• IV fluids: no evidence that they improve

sputum clearance

Asthma: other therapiesMagnesium• Bronchodilation• Clinical effect: studies are mixed

• Improved pulmonary function• No impact on hospital admission

• Seems to be more helpful in severe asthma

Emerg Med J. 2007;24(12):823-30.

Asthma: other therapies

Intubation/mechanical ventilation

• Only as a last resort• Complications from barotrauma common• Not curative

Asthma: other therapies

Intubation/mechanical ventilation

• Ketamine = induction agent of choice• bronchodilator

• Conventional tidal volumes and rate result in hyperinflation• difficulty getting the air out• permissive hypercapnia

Asthma: other therapies

Non-invasive positive pressure ventilation• Bi-PAP, CPAP• May prevent the need for intubation in

severe exacerbations

Severe Asthma

• What are some risk factors for severe exacerbations/death? Prior intubation or ICU admit Multiple hospitalizations or ED visits for

asthma Current use of systemic steroids Frequent use of rescue MDI Comorbidities

Case #2• 71 yo F presents with progressively

increasing dyspnea for 4 days, much worse this morning. Mild non-productive cough. No chest pain.

• + orthopnea: slept in chair last night• PMHx: DM, CAD, GERD

Case #2

• Vitals: 99F 106 212/104 32 87%RA

• Awake, alert, anxious, sweaty, dyspneic

• Diffuse rales

• CXR:

Diagnosis? Acute

Decompensated CHF

What treatments do you want to begin?

CHF exacerbation: therapy

Nitrates• Reduce preload• Cornerstone of therapy in the

ED• SL, transdermal, or IV• Large amounts can be given SL

very quickly

CHF exacerbation: therapy

Furosemide (Lasix)• Reduces preload

• diuresis • venodilation

CHF exacerbation: therapyMorphine• Time-honored treatment for CHF• Mechanism

• decreased preload • decreased catecholamines• anxiolysis

• Respiratory depression• Not a first-line (or even necessary) treatment

CHF exacerbation: therapy

ACEIs

• Effective in long-term management of CHF• Beneficial in acute exacerbations as well• Captopril may be given SL

Acad Emerg Med.1996;3:205-212

CHF exacerbation: therapy

Noninvasive positive pressure ventilation • CPAP: Continuous Positive Airway Pressure• Bi-PAP: Bi-level Positive Airway Pressure

• Different inspiratory (IPAP) and expiratory (EPAP) pressure levels

• Delivered via tight-fitting mask over nose or mouth and nose

CHF exacerbation: therapyNIPPV • Decreases work of breathing• Increases functional residual capacity• Decreases preload (decreased venous

return)• Benefit

Decreases need for intubation Earlier resolution of symptoms NO mortality benefit

Health Technol Assess 2009;13(33):1–106

Case #2

• Patient given O2, nitrates, furosemide, and SL captopril with excellent improvement

• EKG: sinus tach, o/w normal• CBC, BMP, cardiac markers normal• BNP 2480 pg/ml

B-type Natriuretic Peptide

• Produced in response to elevated ventricular pressures

• Part of the neurohormonal response to LV dysfunction

• Basis for the drug nesiritide

B-type Natriuretic Peptide

• A diagnostic test/biomarker for acute CHF• Not always helpful in the acute setting

• Some cases are clinically obvious• May help in dyspnea where the cause is unclear• False positives (PE)• Role still evolving

What about the Blood Pressure?(A few words about BP in acute CHF exacerbations)

• Elevated blood pressure (often very high) is the rule• Increased sympathetic outflow

• The BP does not need to be treated per se• Most of the therapies for acute CHF result in

lower BP, but treating the BP number is not the goal

What about the Blood Pressure?(A few words about BP in acute CHF exacerbations)

Low BP + CHF = Cardiogenic Shock = Sick Vasopressors

Case #3• 66 yo M with hx COPD and continued

smoking presents with several days of increased dyspnea, cough, and sputum production

• VS 986F 92 22 152/88 95% RA• No distress• Diffuse wheezing• CXR:

Treatment?

Treatment of COPD Exacerbations

• Similar to asthma

• Oxygen – treat significant hypoxia • Optimal goal unclear; reasonable to tolerate some

degree of “permissive hypoxia.”

Treatment of COPD Exacerbations• Inhaled beta-agonists• Ipratropium

Smooth muscle relaxation Decreased secretions Particularly effective in COPD

• Systemic corticosteroids• Beneficial for both admitted and discharged

patients

Treatment of COPD ExacerbationsAntibiotics• Infection may play a role in exacerbations• Antibiotics are beneficial, but effect is small• Many appropriate choices

• Similar to pneumonia treatment• Doxycycline • FQs, Macrolides OK but more expensive

Treatment of COPD Exacerbations

• Bi-PAP or CPAP useful in more severe cases

Case #4

• 33 yo M

• “My throat is swelling shut and I can’t breathe!”

• Symptoms began 2 hours ago

• Also notes difficulty swallowing

Case #4

What are some signs/symptoms of acute upper airway obstruction?

Acute Upper Airway ObstructionStridorMuffled or “hot potato”

voiceDroolingRetractions/accessory

muscle useAgitation/anxiety/AMSHypoxia is a late finding

Case #4• Denies fever, cough, chest pain• Mild sore throat yesterday• PMHx: HTN, NIDDM• Meds: HCTZ, lisinopril, metformin

• No new meds• Vitals: 990F 88 24 162/98 99%RA

• Differential dx?

Acute Upper Airway Obstruction

• Angioedema

• Infections:EpiglottitisRetropharyngeal abscessPeritonsillar abscessLudwig’s angina

• Foreign body

• Trauma• Inhalation or

ingestion injury

Case #4

Diagnosis?

Angioedema:Subdermal, localized, well-demarcated, non-pitting edema

Angioedema

1. Drug related• ACEI most common

• May occur years after the drug is started

2. Hereditary• C1 inhibitor deficiency

3. Idiopathic

Angioedema: pathophysiology

All types result in elevated bradykinin levels

C1 inhibitor deficiency

increased bradykinin production

ACEI

decreased bradykinin inactivation

Angioedema: pathophysiology

• Not histamine mediated Antihistamines and steroids are

generally ineffective therapy

Angioedema: treatment

Airway management is critical• Most do not require intubation• Airway obstruction can occur• Monitor closely• Be prepared

• Call for assistance• Difficult airway equipment

Angioedema: treatment

Hereditary• FFP

• Contains some C1-inhibitor• Evidence for efficacy is weak

Angioedema: treatmentHereditary• Newer drugs are effective but very

expensive ($$$$ thousands per dose) Plasma-derived or recombinant C1-INH Kallikrein inhibitors Bradykinin receptor antagonists

Angioedema: treatment

ACEI-induced• Stop the ACEI• Role of other drugs unclear

Case #5• 16 month old presents with 2 days of

cough and dyspnea.• PMHx: “possible asthma”• Meds: prn albuterol

Case #5• VS: 1002F 128 34 97%RA• Well-appearing, non-toxic• Tachypneic, retractions• Faint wheezes on exam

• What is your differential?

Case #5• Asthma• Bronchiolitis• Croup• Pneumonia• Foreign body• Congenital heart disease• Others

Esophagus or trachea? Think of the larynx/cords as a coin slot

Foreign Bodies• 6 mo - 4 yo most common

• Coins, hot dogs, grapes, nuts, candy

• Wide spectrum of presentations, depending on object and location

Foreign Bodies: CXR• Radiolucent objects are

more difficult to find• If in a mainstem bronchus,

may create ball-valve effect, resulting in asymmetric hyperinflation

• Bronchoscopy = Gold Standard

Summary• Many patients with dyspnea will require

intervention based on minimal information• All that wheezes is not asthma• Beta-agonists are the cornerstone of acute

asthma management• Always consider foreign bodies in the

differential for dyspnea