What is the initial assessment and management of an adult presenting with acute unexplained shortness of breath?

Initial Assessment and Management of Acute Unexplained Shortness of Breath in Adults

For an adult presenting with acute unexplained shortness of breath, immediately assess for life-threatening conditions using the ABCDE approach: ensure scene safety, check responsiveness by tapping shoulders and shouting, simultaneously assess breathing and pulse within 10 seconds, and if the patient is unresponsive with absent or only gasping respirations, immediately begin high-quality CPR at 100-120 compressions per minute with 5-6 cm depth while activating emergency services. 1, 2, 3

Immediate Life-Threat Assessment (First 10-30 Seconds)

Scene Safety and Responsiveness

• Verify scene safety before approaching to avoid becoming a second victim 2
• Check responsiveness by gently shaking the patient's shoulders while asking loudly "Are you all right?" 1
• If unresponsive with no breathing or only gasping, this indicates cardiac arrest requiring immediate CPR 4, 1

Simultaneous Breathing and Circulation Check (Maximum 10 Seconds)

• Look for chest movements, listen at the victim's mouth for breath sounds, and feel for air on your cheek while simultaneously checking the carotid pulse at a single site 1
• Occasional gasps do not count as normal breathing and should be treated as absent breathing 4, 1
• If no pulse is definitively palpated within 10 seconds, immediately begin chest compressions 1, 2
• Critical pitfall: Do not check bilateral carotid pulses simultaneously or sequentially, as this wastes time and is not supported by guidelines 1

If Cardiac Arrest is Identified

Immediate Actions (Within First Minute)

• Activate the emergency response system immediately 2
• Begin high-quality chest compressions at 100-120 compressions per minute with depth of 5-6 cm 2
• Ensure complete chest recoil between compressions 2
• Place patient on firm surface with rescuer kneeling beside the victim's chest 4
• Hand position should be at the center of the chest 2

CPR Protocol

• Use 30:2 compression-to-ventilation ratio for single rescuer or two healthcare providers in adults 2
• Minimize interruptions, keeping pauses less than 10 seconds 2
• Apply defibrillator pads as soon as available without interrupting compressions 4, 2
• For shockable rhythms (VF/pulseless VT), deliver one shock immediately and resume CPR for 2 minutes 2
• Administer epinephrine 1 mg IV/IO every 3-5 minutes for all cardiac arrest rhythms 2

If Patient is Responsive with Acute Shortness of Breath

Airway Assessment

• Open the airway using head tilt-chin lift maneuver by placing one hand on the forehead and gently tilting the head back while lifting the chin 1
• If trauma to the neck is suspected, use jaw thrust without head extension instead 1
• Remove any visible obstruction from the mouth, including dislodged dentures, but leave well-fitting dentures in place 1

Breathing Assessment

• Assess respiratory rate, depth, and work of breathing 3
• Look for use of accessory muscles, paradoxical breathing, or cyanosis 3
• Administer 100% oxygen at 15 L/min immediately for any patient with significant respiratory distress 2
• Auscultate lung fields for wheezes, crackles, or diminished breath sounds 5

Circulation Assessment

• Check pulse rate, rhythm, and quality 3
• Assess blood pressure and capillary refill 3
• Establish IV access for potential medication administration 3

Disability (Neurological) Assessment

• Assess level of consciousness using AVPU (Alert, Voice, Pain, Unresponsive) 3
• Check for confusion, agitation, or altered mental status which may indicate hypoxia 3

Exposure

• Expose the chest to look for trauma, asymmetry, or signs of respiratory distress 3
• Check for jugular venous distension suggesting heart failure or tension pneumothorax 3

Critical Differential Diagnoses to Consider

The most common life-threatening causes requiring immediate identification include:

• Cardiac arrest (unresponsive, absent/gasping respirations) 4, 1
• Acute coronary syndrome (chest pain, diaphoresis, ECG changes) 5
• Pulmonary embolism (sudden onset, pleuritic chest pain, risk factors) 6, 5
• Tension pneumothorax (absent breath sounds, tracheal deviation, hypotension) 5
• Acute heart failure (orthopnea, crackles, elevated JVP) 7
• COPD/asthma exacerbation (wheezing, prolonged expiration, history) 6, 5
• Pneumonia (fever, productive cough, focal findings) 6

Common Pitfalls to Avoid

• Do not spend excessive time on pulse checks; if uncertain after 10 seconds, start chest compressions immediately 1
• Do not delay CPR to obtain a detailed history, as the priority is immediate assessment and intervention 2
• Do not assume the patient's history always indicates the cause; a 78-year-old with known COPD and pneumonia was found to have a foreign body obstruction on bronchoscopy 6
• Do not perform violent shaking during responsiveness checks, as this could cause head or cervical spine injuries 1
• Avoid delays in moving to the next assessment step if initial maneuvers are unsuccessful 1

Simultaneous Team-Based Approach

When multiple rescuers are available, actions should occur simultaneously rather than sequentially:

• One rescuer checks responsiveness and breathing while another activates emergency services 4
• A third rescuer retrieves the defibrillator while a fourth prepares bag-mask ventilation equipment 4
• This parallel approach minimizes time to critical interventions 4