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Respiratory Distress, Emergency Medicine

Basics

Description

- Bioterrorist threats: - Anthrax - Pneumonic plague - Tularemia - Viral hemorrhagic fevers

- Respiratory failure is the most common cause of cardiac arrest in infants. - Croup syndromes include: - Viral - Spasmodic - Bacterial - Congenital defects - Noninflammatory causes (foreign body, gastroesophageal reflux, trauma, tumors)

- Epiglottitis: - Highest incidence at ages 2 " 4 yr - Abrupt onset - Fever - Respiratory distress and stridor - Difficulty swallowing oral secretions - Restlessness and anxiety

- Treat underlying etiology as appropriate. - CHF or pulmonary edema: - Diuretics - Nitroglycerin - Nitroprusside if hypertensive - Pulmonary artery catheter if severe - Noninvasive positive-pressure ventilation (NPPV/BiPAP) or intubation if severe

- ARDS, aspiration, toxic lung injury: - Mechanical ventilation as needed - Steroids controversial

- Croup: - Cool, misted air or oxygen - Steroids - Racemic epinephrine - Antibiotics for bacterial infection

- Anaphylaxis, angioedema: - IV steroids - H1/H2-blockers - SQ or IV epinephrine - Early intubation

- Cardiac: - Treat dysrhythmias or ischemia - Anticoagulation or thrombolysis for PE - Pericardiocentesis for tamponade - NSAIDs or aspirin for pericarditis

- Transtracheal jet ventilation if unable to intubate (cricothyrotomy not recommended in children <10 yr) - Bronchiolitis: - Bronchodilators - Antivirals for respiratory syncytial virus - Antibiotics for infection

- Continued supplemental oxygen requirement - Cardiac or hemodynamic instability: - Requiring IV therapy or hydration - Requiring close airway observation or repeated treatments - Respiratory isolation

Respiratory distress, shortness of breath, or dyspnea is a common complaint for patients presenting to the ED.

Etiology

  • Upper airway obstruction:EpiglottitisCroup syndromesLaryngotracheobronchitisForeign bodyAngioedemaRetropharyngeal abscess
  • Cardiovascular:Pulmonary edema/CHFDysrhythmiasCardiac ischemiaPulmonary embolusPericarditisTamponadeAir embolism
  • Pulmonary:AsthmaChronic obstructive pulmonary disease (COPD)/emphysemaPneumoniaInfluenzaBronchiolitisAspirationAdult respiratory distress syndrome (ARDS)Pulmonary edemaPleural effusionToxic inhalation injury
  • Trauma:PneumothoraxTension pneumothoraxRib fracturesPulmonary contusionFat embolism with long-bone fractures
  • Neuromuscular:Guillain " Barre syndromeMyasthenia gravis
  • Metabolic/systemic/toxic:AnaphylaxisAnemiaAcidosisHyperthyroidismSepsisSeptic emboli from IV drug use or infected indwelling linesSalicylate intoxicationDrug overdoseAmphetaminesCocaineSympathomimeticObesity
  • Psychogenic:Anxiety disorderHyperventilation syndrome
  • Bioterrorist threats:AnthraxPneumonic plagueTularemiaViral hemorrhagic fevers
  • Respiratory failure is the most common cause of cardiac arrest in infants.
  • Croup syndromes include:ViralSpasmodicBacterialCongenital defectsNoninflammatory causes (foreign body, gastroesophageal reflux, trauma, tumors)
  • Most common cause of upper airway obstruction:<6 mo: Congenital laryngomalacia>6 mo: Viral croup
  • Epiglottitis:Highest incidence at ages 2 " 4 yrAbrupt onsetFeverRespiratory distress and stridorDifficulty swallowing oral secretionsRestlessness and anxiety
  • Amniotic fluid embolism during or after delivery
  • Septic embolism from septic abortion or postpartum uterine infection

Diagnosis

Signs and Symptoms

  • Tachypnea
  • Dyspnea
  • Tachycardia
  • Anxiety
  • Diaphoresis
  • Cough ( "barking, " productive)
  • Stridor
  • Hoarse voice
  • Difficulty swallowing or handling oral secretions
  • Upper airway rhonchi (wheezes)
  • Lower airway crackles (rales)
  • Increased work of breathing
  • Accessory and intercostal muscle use
  • Hypoxemia
  • Hypocapnia or hypercapnia if severe
  • Respiratory acidosis
  • Cyanosis
  • Lethargy, then obtundation

History

  • Previous history of asthma, COPD, cardiac disease, or dysrhythmia, CHF, foreign-body aspiration, or toxic exposure
  • Recent fever or upper respiratory tract infection, cough, sputum production, sore throat, systemic disease, anxiety disorder
  • Recent chest or long-bone trauma
  • IV drug use or indwelling catheters
  • Recurrent fevers, night sweats, weight loss

Physical Exam

  • Observe: Mental status, level of distress, work of breathing, jugular venous pressure, skin color
  • Feel/palpate: Distal pulses, heart perioperative MI, chest wall, peripheral edema
  • Percuss: Lungs for dullness or resonance, abdominal distention, or hepatomegaly
  • Auscultate: Heart sounds, murmurs, lung wheezes or crackles, neck for upper airway stridor, abdomen bowel sounds
  • Evaluate retractions, behavior, respiratory rate, breath sounds, and skin color.
  • Weak cry, expiratory grunting, nasal flaring, tachypnea and tachycardia, retractions, and cyanosis in neonates

Essential Workup

  • Pulse oximetry
  • Cardiac and BP monitoring
  • EKG if suspected cardiac etiology

Diagnosis Tests & Interpretation

Lab

  • ABG for severity and acid " base determination
  • CBC
  • Electrolytes, BUN/creatinine, glucose
  • Sputum cultures, smears, and Gram stain
  • Blood cultures for fever or sepsis
  • B-type natriuretic peptide (BNP) for undifferentiated shortness of breath or CHF severity
  • Venous thromboembolus test (VTE) for low-risk PE
  • HIV
  • Seasonal and "novel " flu testing
  • Urinary output monitoring for CHF
  • Toxicology screen or salicylate level if suspected

Imaging

  • CXR for:PneumoniaPneumothoraxHyperinflationAtelectasisCHF/pulmonary edemaAbscess/cavitary lesions/other infiltratesTuberculosis
  • Ultrasound for:Lung and rib evaluation using linear transducerPneumothoraxHemothorax/pleural effusionCHFRib fractures
  • Echocardiography using phased array transducer:Cardiac effusion/tamponadeCHF/cardiac dilatationRV dilatation for PE
  • Spirometry (peak expiratory flow rates) for asthma, COPD
  • Neck CT or radiographs to assess epiglottis and soft-tissue spaces, foreign body
  • CT angiography or ventilation/perfusion scan for pulmonary embolus
  • Chest/neck radiograph may show foreign body or "steeple sign " in croup syndromes.
  • Chest fluoroscopy may be used to assess inspiratory and expiratory excursions if foreign body is suspected.

Diagnostic Procedures/Surgery

  • Fiberoptic laryngoscopy to assess epiglottis, vocal cords, and pharyngeal space
  • Bronchoscopy for foreign body in trachea or bronchus
  • Pulmonary artery (Swan-Ganz) catheter for severe CHF, ARDS, pulmonary edema

Differential Diagnosis

See Etiology.

Treatment

Pre-Hospital

  • Assume a position of comfort for patient.
  • 100% oxygen:Assisted bag-valve mask (BMV) ventilation if obtunded
  • Airway adjunct devices (oral or nasal) to maintain patency if tolerated
  • Intubation for severe respiratory distress
  • Needle aspiration of suspected tension pneumothorax

Initial Stabilization/Therapy

  • ABCs
  • Ensure patent airway; BVM assist or intubate for severe distress or arrest
  • IV fluids if hypotensive
  • 100% oxygen by face mask:Use cautiously in patients with severe COPD or chronic CO2 retention.
  • Monitor BP, heart rate, respirations, pulse oximetry
  • Advanced cardiac life support for dysrhythmias or arrest

Ed Treatment/Procedures

  • Treat underlying etiology as appropriate.
  • CHF or pulmonary edema:DiureticsNitroglycerinNitroprusside if hypertensivePulmonary artery catheter if severeNoninvasive positive-pressure ventilation (NPPV/BiPAP) or intubation if severe
  • Asthma, bronchiolitis, COPD:BronchodilatorsSteroidsAntibiotics for infectionAntivirals for influenzaNPPV or intubation if severe
  • ARDS, aspiration, toxic lung injury:Mechanical ventilation as neededSteroids controversial
  • Pneumonia:AntibioticsRespiratory isolation for TB
  • Pneumothorax:Immediate decompression if suspected tension pneumothoraxAspiration or tube thoracostomy (see Pneumothorax)
  • Pleural effusion:Determine etiologyDiagnostic and symptomatic thoracentesis
  • Croup:Cool, misted air or oxygenSteroidsRacemic epinephrineAntibiotics for bacterial infection
  • Epiglottitis:Immediate airway stabilization with intubation or tracheostomy in OR if possibleAntibiotics for Haemophilus influenzae
  • Anaphylaxis, angioedema:IV steroidsH1/H2-blockersSQ or IV epinephrineEarly intubation
  • Retropharyngeal abscess:DrainageIV antibioticsENT consult
  • Cardiac:Treat dysrhythmias or ischemiaAnticoagulation or thrombolysis for PEPericardiocentesis for tamponadeNSAIDs or aspirin for pericarditis
  • Neuromuscular:Support ventilationPyridostigminebromide or neostigmine for myasthenia gravis
  • Metabolic/toxic:
  • Psychogenic:
  • Transtracheal jet ventilation if unable to intubate (cricothyrotomy not recommended in children <10 yr)
  • Bronchiolitis:BronchodilatorsAntivirals for respiratory syncytial virusAntibiotics for infection
  • Spasmodic croup:Very sensitive to misted air
  • Bacterial croup (membranous laryngotracheobronchitis):Treat Staphylococcus aureus.
  • Supportive oxygen therapy and heparin for PE or amniotic fluid embolism
  • IV antibiotics for septic embolism

Medication

Refer to specific etiologies

Follow-Up

Disposition

Admission Criteria

  • Continued supplemental oxygen requirement
  • Cardiac or hemodynamic instability:Requiring IV therapy or hydrationRequiring close airway observation or repeated treatmentsRespiratory isolation
  • As required by underlying cause or significant comorbid disease

Discharge Criteria

  • Correction of underlying disease
  • Stable airway
  • Acute supplemental oxygen not required

Issues for Referral

Refer to specific etiologies

Pearls and Pitfalls

  • Consider immune-compromised state.
  • Consider "novel " flu strains (H1N1).
  • Start antibiotic treatment within 6 hr of ED arrival (JCAHO Quality Measure).

Additional Reading

  • Ausiello D, Goldman L, eds. Cecil Textbook of Medicine. 22nd ed. Philadelphia, PA: WB Saunders; 2004:492 " 583, 1523 " 1524.
  • Barton ED, Collings J, DeBlieux PMC, et al., eds. Emergency Medicine: Clinical Essentials. 2nd ed. Philadelphia, PA: Elsevier Saunders; 2009:43 " 49, 173, 398, 414 " 434, 476 " 486, 1351 " 1368.
  • Sigillito RJ, DeBlieux PM. Evaluation and initial management of the patient in respiratory distress. Emerg Med Clin North Am. 2003;21(2):239 " 258.
  • Williams SA, Hutson HR, Speals HL. Dyspnea. In: Emergency Medicine: Concepts and Clinical Practice. 4th ed. St. Louis, MO: Mosby; 1998:1460 " 1469.

Codes

ICD9

  • 786.00 Respiratory abnormality, unspecified
  • 786.05 Shortness of breath
  • 786.09 Other respiratory abnormalities
  • 464.4 Croup
  • 464.30 Acute epiglottitis without mention of obstruction
  • 490 Bronchitis, not specified as acute or chronic
  • 519.8 Other diseases of respiratory system, not elsewhere classified

ICD10

  • R06.00 Dyspnea, unspecified
  • R06.02 Shortness of breath
  • R06.09 Other forms of dyspnea
  • J05.0 Acute obstructive laryngitis [croup]
  • J05.10 Acute epiglottitis without obstruction
  • J40 Bronchitis, not specified as acute or chronic
  • J98.8 Other specified respiratory disorders

SNOMED

  • 271825005 Respiratory distress (finding)
  • 267036007 Dyspnea (finding)
  • 230145002 difficulty breathing (finding)
  • 71186008 Croup (disorder)
  • 68372009 Upper respiratory tract obstruction (disorder)
  • 80384002 Epiglottitis (disorder)
  • 85915003 Laryngotracheobronchitis