Shortness of breath resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Steven Bellm, M.D. [2]

Shortness of breath resident survival guide Microchapters
Overview
Definitions
Causes
FIRE
Diagnosis and Treatment

Overview

Dyspnea is a symptom, it must generally be distinguished from signs that clinicians typically invoke as evidence of respiratory distress, such as tachypnea, use of accessory muscles, and intercostal retractions.

Respiratory discomfort may arise from many clinical conditions, but also may be a manifestation of poor cardiovascular fitness in our increasingly sedentary population. Diagnosis and treatment of the underlying cause of dyspnea is the preferred and most direct approach to improve this symptom, but there are many patients for whom the cause is unclear or for whom dyspnea persists despite optimal treatment.

Definitions

• Dyspnea

A subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity.

• Tachypnea

A respiratory rate greater than normal.

• Bradypnea

A respiratory rate smaller than normal.

• Hyperpnea

Increased minute ventilation to meet metabolic requirements.

• Hyperventilation

It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide.

• Dyspnea on exertion

Dyspnea caused by physical effort or exertion.

• Orthopnea

Dyspnea caused by a recumbent position.

• Paroxysmal nocturnal dyspnea

Dyspnea that starts suddenly while reclining at night.

• Platypnea

Dyspnea that starts in an upright position.

• Trepopnea

Dyspnea that starts in one lateral decubitus position as opposed to the other.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Life-threatening causes of the upper airway

• Aspiration foreign body
• Angioedema
• Anaphylaxis
• Infections of the pharynx and neck
• Airway trauma

• Life-threatening pulmonary causes

• Pulmonary embolism
• COPD
• Asthma
• Pneumothorax and pneumomediastinum
• Pneumonia
• Adult Respiratory Distress Syndrome
• Chest trauma
• Pulmonary hemorrhage

• Life-threatening cardiac causes

• Acute coronary syndrome
• Acute decompensated heart failure
• Flash pulmonary edema
• High output failure
• Cardiomyopathy
• Cardiac arrhythmia
• Valvular dysfunction
• Cardiac tamponade

• Life-threatening neurologic causes

• Stroke
• Neuromuscular disease

• Life-threatening toxic and metabolic causes

• Poisoning
• Salicylate poisoning
• Carbon monoxide poisoning
• Toxin related metabolic acidosis
• Diabetic ketoacidosis
• Sepsis
• Anemia
• Acute chest syndrome- in patients with sickle cell disease

Miscellaneous Causes

• Lung cancer
• Pleural effusion
• Intraabdominal infection
• Ascites
• Pregnancy
• Morbid obesity
• Hyperventilation and anxiety

FIRE: Focused Initial Rapid Evaluation

A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention.

Dyspnea

Initial evaluation: ❑   Check Vital Signs: ❑  Heart rate ❑  Respiratory rate ❑  Blood pressure ❑   Danger signs: Depressed mental status, cyanosis, inability to maintain respiratory effort, use of accessory muscles, abnormal chest movement ❑  Action items ❑   Supplement oxygen ❑   IV access and pulse oximetry ❑  ECG/cardiac monitor ❑  ± Continuous waveform capnography ❑  Lab measurements: ❑  ABG, SaO2, A-a gradient ❑  WBC, Hgb, Hct, Platelets ❑  BUN, Cr, K, Mg, Phos ❑  Glucose ❑  D-Dimer, NT-proBNP, Troponin ❑  Keep airway managment equipment ready

Signs for rapidly reversible causes?

Yes

Tension pneumothorax: ❑  Signs: ❑  Chest pain ❑  Hypotension ❑  Tracheal deviation ❑  Jugular-venous distension ❑  Quieter breath sounds/hyperresonant percussion ❑  Tachycardia/tachypnea ❑  Treatment: ❑  Immediate chest decompression by needle or tube thoracostomy

Upper airway foreign body aspieation: ❑  Signs: ❑  Coughing, cyanosis ❑  Treatment: ❑  Bronchoscopy/Laryngoscopy

Pericardial tamponade: ❑  Signs(Becks's triade): ❑  Hypotension ❑  Muffled heart sounds ❑  Jugular-venous distension ❑  Treatment: ❑  Pericardiocentesis

No

Ability to maintain own airway?

No

Action items: ❑  Try to assess ventilation ❑  Check breath sounds ❑  Endotracheal intubation/cricothyrotomy and mechanical ventilation

Yes

Chest x-ray

Assess breath sounds, obtain history and physical exam

Proceed to Complete Diagnostic Approach

Complete Diagnostic Approach and Treatment

A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention

History and symptpms: ❑  Shortness of breath ❑  Grunting or wheezing sounds while breathing ❑  Exposure to something the patient may be allergic to may cause shortness of breath ❑  Exercise may cause shortness of breath ❑  Onset:Sudden or slowly? ❑  Duration:Slowly progress over weeks to months? ❑  Positional Changes:Shortness of breath may worsen when the patient changes body position. Sometimes it is worse when you lie flat (orthopnea). Sometimes breathing difficulty occur while the patient is resting. Is there a paroxysmal nocturnal dyspnea? ❑  Trauma? ❑  Past medical illness?

Physical examination: ❑  Vital signs: ❑  Fever, Tachypnea, Hypopnea, Tachycardia, Hypotension? ❑  General appearance: ❑  Cachexia, obesity, pregnancy, barrel chest, "sniffing" position, "tripoding" position, traumatic injury? ❑  Neck: ❑  Jugular venous distension, stridor? ❑  Skin and nails: ❑  Tobacco stains, clubbing, pallid skin, muscle wasting, bruising, subcutaneous emphysema, hives, rashes? ❑  Lungs: ❑  Wheezing, crackles, rales, unilateral decrease, hemoptysis, Friction rub, abnormal respiratory pattern? ❑  Heart: ❑  Heart murmurs, S3, S4, muffled heart sounds? ❑  Extremities: ❑  Peripheral edema, palpation of peripheral arteries, signs for cyanosis, swelling or tenderness? ❑  Neurologic examination: ❑  Focal deficit, symmetrical deficit, diffuse weakness, hyporeflexia, ascending weakness? ❑  Any pain or panic symptoms?

Laboratory findings: The following tests are performed to evaluate dyspnea: ❑  Arterial blood gases, pulse oximetry, waveform capnography: ❑  Hypoxia, hyperventilation, CO² retention, obstructive or restrictive respiratory pattern, metabolic vs. respiratory acidosis, A-a gradient, elevated carboxyhemoglobin? ❑  Complete blood count: ❑  WBC, Hgb, Hct, anemia, polycythemia, smear, platelets? ❑  Chemistry: ❑  BUN, Cr, K, Mg, Phos, Glucose, D-Dimer, Troponin, NT-proBNP, thyroid function tests?

Imaging and aditional tests: ❑  Cardiac: ❑  ECG (ischemia, dysrhythmia, S¹Q³T³, right sided heart strain) ❑  Echocardiogram (pulmonary hypertension, valvular disorders, wall motion abnormalities related to ischemia, intracrdiac shunts) ❑  Cardiopulmonary exercise testing ❑  Pulmonary function test/ spirometry ❑  Radiologic: ❑  CXR (bone structures, mass, diaphragm, mediastinum, cardiac silhouette, soft tissue, lung parenchyma) ❑  V/Q scan (PE?) ❑  Pulmonary angiogram (PE?) ❑  CT (mass lesion, adenopathy, trauma, PE?) ❑  MRI (PE, bony and soft tissue lesions, vascular abnormality?) ❑  Soft tissue neck radiography (epiglottitis, foreign body?) ❑  Ultrasound (pneumothorax, pleural effusion, impaired cardiac function or pericardial effusion?) ❑  Fiberoptic: ❑  Bronchoscopy (mass lesions, foreign body, intervention?) ❑  Laryngoscopy (mass lesion, edema epiglottis foreign body?)

Differential diagnosis based on history, physical examination, labaratory and test findings

Chest trauma: Treatment as fast as possible. ❑  Tension pneumothorax: Immediate chest decompression by needle or tube thoracostomy ❑  Pulmonary contusion, multiple rib fractures: Pain management ❑  Inhalation injury: Early endotracheal intubation

Anaphylaxis: ❑  Secure airway if needed: endotracheal intubation, cricothyrotomy ❑  Epinephrine IV (extreme) if needed, SQ ❑  Steroids IV ❑  Diphenhydramine IV ❑  Inhaled beta-agonist ❑  Consider inhaled racemic epinephrine, heliox ❑  H¹/H² blocker IV

Pneumonia: ❑  Blood/sputum cultures ❑  Initiate appropriate empirical antibiotic, antifungal or antiviral medication promptly ❑  Isolation if needed

Cardiac: ❑  Dysrhythmia: antiarrhythmics or cardioversion ❑  Coronary heart disease: nitrates, ASA, pain management, thrombolysis, beta-blockade, PCA ❑  Heart failure: diuretics, nitrates, morphine, ACE

Pulmonary embolism: ❑  Initiate anticoagulation with IV heparin or subcutaneous low-molecular-weight heparin ❑  Consider systemic thrombolysis if unstable ❑  Consider interventional clot lysis with pulmonary angiography

Asthma or COPD exacerbation: ❑  Inhaled beta-agonist ❑  Steroids IV ❑  Consider other adrenergics ❑  Treat concurrent infection ❑  Counsel smoking cessation if appropiate

In Case of respiratory failure

❑  CPAP/BiPAP (short term) or endotracheal intubation, and mechanical ventilation ❑  Treat underlying causes

References