Download - Approach to Dyspnea
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