AQ-ERE

Heart & Thorax12 min readv1.0 · reviewed 10 June 2026Pending partner review (Notfallguru)

Dyspnea & Respiratory Failure

A structured approach to acute dyspnea: from ruling out the five killers to treating the most likely cause without delay.

Killers — rule out first

Airway obstruction
Stridor, acute hoarseness, foreign body, angioedema — secure the airway first.
Tension pneumothorax
Unilateral absent breath sounds + hypotension + tracheal shift — immediate needle decompression.
Massive pulmonary embolism
Hypoxia with a clinically "clean" chest and right-heart strain.
Acute cardiogenic pulmonary edema (SCAPE)
Severe distress + diffuse crackles + hypertension — early CPAP and nitrates.
Near-fatal asthma
Silent chest, exhaustion, altered consciousness — prepare for ventilation and call for help now.

Red flags

SpO₂ below 90% despite oxygen
Respiratory rate above 30/min or below 8/min
Single-word speech and accessory muscle use
Altered consciousness or visible exhaustion
Central cyanosis
Shock signs: hypotension, pallor, tachycardia

First steps

Immediate ABCDE assessmentAction
Airway patent? Work of breathing and chest symmetry? Pulse, pressure, consciousness. Treat each problem as you find it before moving on.
Titrated oxygenDrug
Target 94–98% for most, 88–92% when at risk of hypercapnia (COPD). Never withhold oxygen from a hypoxic patient for fear of CO₂ retention.
Sit the patient up + continuous monitoringAction
Upright position, continuous SpO₂/rhythm/BP monitoring. A distressed patient is never left alone.
ECG within 10 minutesDiagnostic
Detects ischemia, arrhythmia, and right-heart strain. Add an arterial blood gas when available.
Chest X-ray or POCUSDiagnostic
Bedside lung ultrasound (when available) rapidly separates edema, pneumothorax, and effusion.
IV access and bloodsAction
CBC, electrolytes, renal function, CRP; troponin and D-dimer as the clinical context dictates.
Treat the most likely cause nowAction
Do not wait for the full picture: bronchodilators for wheeze, CPAP and nitrates for edema, needle decompression for tension pneumothorax.

Clinical pearls

A normal SpO₂ does not exclude danger when work of breathing is severe — patients compensate until they suddenly collapse.

Hypoxia with a clean chest on auscultation? Think pulmonary embolism.

A patient who refuses to lie flat usually has pulmonary edema or true distress — believe them.

Transport sitting upright. Start oxygen early and never delay transport for non-lifesaving procedures. Pre-alert the ED for every critical case; start NIV in the ambulance when available and appropriate.

Differential diagnosis

Condition	Clues	Urgency
Cardiogenic pulmonary edema	Bilateral crackles, cardiac history, hypertension, relief on sitting up.	Immediate
Acute asthma	Diffuse expiratory wheeze, asthma history, bronchodilator response.	Immediate
Pneumothorax	Sudden pleuritic pain, unilateral absent sounds, tall thin patient or trauma.	Immediate
Pulmonary embolism	Unexplained hypoxia, thrombotic risk factors, pleuritic pain, tachycardia.	Immediate
COPD exacerbation	Smoker, known COPD, increased sputum, wheeze with poor air entry.	Urgent
Pneumonia	Fever, purulent sputum, focal crackles, raised inflammatory markers.	Urgent

Cardiogenic pulmonary edemaImmediate
Bilateral crackles, cardiac history, hypertension, relief on sitting up.
Acute asthmaImmediate
Diffuse expiratory wheeze, asthma history, bronchodilator response.
PneumothoraxImmediate
Sudden pleuritic pain, unilateral absent sounds, tall thin patient or trauma.
Pulmonary embolismImmediate
Unexplained hypoxia, thrombotic risk factors, pleuritic pain, tachycardia.
COPD exacerbationUrgent
Smoker, known COPD, increased sputum, wheeze with poor air entry.
PneumoniaUrgent
Fever, purulent sputum, focal crackles, raised inflammatory markers.

Conditions in detail

Acute worsening of respiratory symptoms beyond usual daily variation, often infection-triggered. The core danger is hypercapnic respiratory failure.

Diagnostic workup

Diagnostic0/4

ABG: respiratory acidosis (pH < 7.35 with raised CO₂)?
Chest X-ray to exclude coexisting pneumonia or pneumothorax
ECG + electrolytes and renal function
Purulent sputum? (guides the antibiotic decision)

Therapy

Therapy0/5

Oxygen titrated to 88–92%
Nebulized bronchodilators, repeated to response
Early systemic corticosteroid
NIV when respiratory acidosis persists despite initial therapy
Antibiotic for purulent sputum or pneumonia

Illustrative adult dosing

Drug	Dose	Route	Notes
Salbutamol	2.5–5 mg nebulized	Nebulizer	Repeat every 20 min as needed
Ipratropium	0.5 mg nebulized	Nebulizer	Add in moderate–severe cases
Prednisolone	40 mg PO	Oral	Or hydrocortisone 100 mg IV if oral not possible

Teaching examples — subject to clinical review and local protocol before adoption.

Warning

NIV is the lifesaving intervention in hypercapnic respiratory failure — do not delay it hoping for spontaneous improvement.

Severity is judged by speech, consciousness, SpO₂, and respiratory rate — not wheeze loudness; a silent chest is a peri-arrest sign.

Therapy

Therapy0/5

Oxygen to 94–98%
Repeated or continuous nebulized salbutamol in severe attacks
Systemic steroid within the first hour
IV magnesium sulfate in severe non-responding cases
Early ICU escalation at any sign of exhaustion

Illustrative adult dosing

Drug	Dose	Route	Notes
Salbutamol	5 mg nebulized	Nebulizer	Back-to-back or continuous
Magnesium sulfate⚠ Critical	2 g IV over 20 min	IV	Severe attacks

Teaching examples — subject to clinical review before adoption.

Airway management chart — Illustrative figure: airway management sequence in respiratory failure — to be replaced by the approved chart after review.

Escalation principles in acute asthma:

Reassess every 15–20 minutes after each bronchodilator round:
- Improving speech and consciousness?
- Less accessory-muscle use?
- Better SpO₂ and respiratory rate?
Signs mandating immediate ICU involvement:
- Exhaustion or drowsiness
- Silent chest despite therapy
- Failing oxygenation despite high-flow oxygen
Revisit the killers and the differentials when there is no response — it may not be asthma.

Full guideline reference: GINA — ginasthma.org

Typical patient: sudden severe distress with hypertension and diffuse crackles. Priority is ventilatory support and afterload reduction — not diuretics alone.

Therapy

Therapy0/5

Sit fully upright + oxygen
Early CPAP/NIV — reduces intubation need
Nitrates when systolic pressure is adequate (≈ > 110 mmHg)
Loop diuretic when clearly fluid-overloaded
Hunt the trigger: ischemia, arrhythmia, severe hypertension

Grade severity with CRB-65 to guide disposition, and start antibiotics early in severe disease.

CRB-65

0 / 4

One point per criterion — guides admission decision.

New confusion+1
Respiratory rate ≥ 30/min+1
Systolic < 90 or diastolic ≤ 60 mmHg+1
Age ≥ 65 years+1

Interpretation

0: usually home treatment · 1–2: consider admission · 3–4: severe — assess ICU need.

Therapy

Therapy0/3

Antibiotic within the first hour in severe/septic cases
Guided IV fluids and antipyretics as needed
Oxygen to the appropriate target

Estimate clinical probability before D-dimer or imaging; in massive PE with hemodynamic collapse, thrombolysis is lifesaving.

Info

Hypoxia with no obvious cause on imaging and auscultation = pulmonary embolism until proven otherwise.

Tension pneumothorax is a clinical diagnosis, not a radiological one.

Warning

Suspected tension pneumothorax: immediate needle decompression then chest drain — never wait for the X-ray.

References

ERC Guidelines 2021 — Adult advanced life support (2021)Open source in new tab
GOLD Report 2024 — COPD diagnosis & management (2024)Open source in new tab
GINA 2024 — Global strategy for asthma management (2024)Open source in new tab
ESC Guidelines 2021 — Acute and chronic heart failure (2021)Open source in new tab

Governance & review

Author: Dr. Lina Hassan; Medical Director
Scientific review: Dr. Hassan Karim; Project Director
Last reviewed: 10 June 2026
Version: 1.0

بنية العرض مقتبسة من Notfallguru.de بموافقة فريقه — المحتوى بانتظار مراجعتهم

This content is an educational reference and does not replace clinical judgement or local protocols.

Heart & Thorax12 min readv1.0 · reviewed 10 June 2026Pending partner review (Notfallguru)

Dyspnea & Respiratory Failure

A structured approach to acute dyspnea: from ruling out the five killers to treating the most likely cause without delay.

Killers — rule out first

Airway obstruction
Stridor, acute hoarseness, foreign body, angioedema — secure the airway first.
Tension pneumothorax
Unilateral absent breath sounds + hypotension + tracheal shift — immediate needle decompression.
Massive pulmonary embolism
Hypoxia with a clinically "clean" chest and right-heart strain.
Acute cardiogenic pulmonary edema (SCAPE)
Severe distress + diffuse crackles + hypertension — early CPAP and nitrates.
Near-fatal asthma
Silent chest, exhaustion, altered consciousness — prepare for ventilation and call for help now.

Red flags

SpO₂ below 90% despite oxygen
Respiratory rate above 30/min or below 8/min
Single-word speech and accessory muscle use
Altered consciousness or visible exhaustion
Central cyanosis
Shock signs: hypotension, pallor, tachycardia

First steps

Immediate ABCDE assessmentAction
Airway patent? Work of breathing and chest symmetry? Pulse, pressure, consciousness. Treat each problem as you find it before moving on.
Titrated oxygenDrug
Target 94–98% for most, 88–92% when at risk of hypercapnia (COPD). Never withhold oxygen from a hypoxic patient for fear of CO₂ retention.
Sit the patient up + continuous monitoringAction
Upright position, continuous SpO₂/rhythm/BP monitoring. A distressed patient is never left alone.
ECG within 10 minutesDiagnostic
Detects ischemia, arrhythmia, and right-heart strain. Add an arterial blood gas when available.
Chest X-ray or POCUSDiagnostic
Bedside lung ultrasound (when available) rapidly separates edema, pneumothorax, and effusion.
IV access and bloodsAction
CBC, electrolytes, renal function, CRP; troponin and D-dimer as the clinical context dictates.
Treat the most likely cause nowAction
Do not wait for the full picture: bronchodilators for wheeze, CPAP and nitrates for edema, needle decompression for tension pneumothorax.

Clinical pearls

A normal SpO₂ does not exclude danger when work of breathing is severe — patients compensate until they suddenly collapse.

Hypoxia with a clean chest on auscultation? Think pulmonary embolism.

A patient who refuses to lie flat usually has pulmonary edema or true distress — believe them.

Differential diagnosis

Condition	Clues	Urgency
Cardiogenic pulmonary edema	Bilateral crackles, cardiac history, hypertension, relief on sitting up.	Immediate
Acute asthma	Diffuse expiratory wheeze, asthma history, bronchodilator response.	Immediate
Pneumothorax	Sudden pleuritic pain, unilateral absent sounds, tall thin patient or trauma.	Immediate
Pulmonary embolism	Unexplained hypoxia, thrombotic risk factors, pleuritic pain, tachycardia.	Immediate
COPD exacerbation	Smoker, known COPD, increased sputum, wheeze with poor air entry.	Urgent
Pneumonia	Fever, purulent sputum, focal crackles, raised inflammatory markers.	Urgent

Cardiogenic pulmonary edemaImmediate
Bilateral crackles, cardiac history, hypertension, relief on sitting up.
Acute asthmaImmediate
Diffuse expiratory wheeze, asthma history, bronchodilator response.
PneumothoraxImmediate
Sudden pleuritic pain, unilateral absent sounds, tall thin patient or trauma.
Pulmonary embolismImmediate
Unexplained hypoxia, thrombotic risk factors, pleuritic pain, tachycardia.
COPD exacerbationUrgent
Smoker, known COPD, increased sputum, wheeze with poor air entry.
PneumoniaUrgent
Fever, purulent sputum, focal crackles, raised inflammatory markers.

Conditions in detail

Acute worsening of respiratory symptoms beyond usual daily variation, often infection-triggered. The core danger is hypercapnic respiratory failure.

Diagnostic workup

Diagnostic0/4

ABG: respiratory acidosis (pH < 7.35 with raised CO₂)?
Chest X-ray to exclude coexisting pneumonia or pneumothorax
ECG + electrolytes and renal function
Purulent sputum? (guides the antibiotic decision)

Therapy

Therapy0/5

Oxygen titrated to 88–92%
Nebulized bronchodilators, repeated to response
Early systemic corticosteroid
NIV when respiratory acidosis persists despite initial therapy
Antibiotic for purulent sputum or pneumonia

Illustrative adult dosing

Drug	Dose	Route	Notes
Salbutamol	2.5–5 mg nebulized	Nebulizer	Repeat every 20 min as needed
Ipratropium	0.5 mg nebulized	Nebulizer	Add in moderate–severe cases
Prednisolone	40 mg PO	Oral	Or hydrocortisone 100 mg IV if oral not possible

Teaching examples — subject to clinical review and local protocol before adoption.

Warning

NIV is the lifesaving intervention in hypercapnic respiratory failure — do not delay it hoping for spontaneous improvement.

Severity is judged by speech, consciousness, SpO₂, and respiratory rate — not wheeze loudness; a silent chest is a peri-arrest sign.

Therapy

Therapy0/5

Oxygen to 94–98%
Repeated or continuous nebulized salbutamol in severe attacks
Systemic steroid within the first hour
IV magnesium sulfate in severe non-responding cases
Early ICU escalation at any sign of exhaustion

Illustrative adult dosing

Drug	Dose	Route	Notes
Salbutamol	5 mg nebulized	Nebulizer	Back-to-back or continuous
Magnesium sulfate⚠ Critical	2 g IV over 20 min	IV	Severe attacks

Teaching examples — subject to clinical review before adoption.

Escalation principles in acute asthma:

Reassess every 15–20 minutes after each bronchodilator round:
- Improving speech and consciousness?
- Less accessory-muscle use?
- Better SpO₂ and respiratory rate?
Signs mandating immediate ICU involvement:
- Exhaustion or drowsiness
- Silent chest despite therapy
- Failing oxygenation despite high-flow oxygen
Revisit the killers and the differentials when there is no response — it may not be asthma.

Full guideline reference: GINA — ginasthma.org

Typical patient: sudden severe distress with hypertension and diffuse crackles. Priority is ventilatory support and afterload reduction — not diuretics alone.

Therapy

Therapy0/5

Sit fully upright + oxygen
Early CPAP/NIV — reduces intubation need
Nitrates when systolic pressure is adequate (≈ > 110 mmHg)
Loop diuretic when clearly fluid-overloaded
Hunt the trigger: ischemia, arrhythmia, severe hypertension

Grade severity with CRB-65 to guide disposition, and start antibiotics early in severe disease.

CRB-65

0 / 4

One point per criterion — guides admission decision.

New confusion+1
Respiratory rate ≥ 30/min+1
Systolic < 90 or diastolic ≤ 60 mmHg+1
Age ≥ 65 years+1

Interpretation

0: usually home treatment · 1–2: consider admission · 3–4: severe — assess ICU need.

Therapy

Therapy0/3

Antibiotic within the first hour in severe/septic cases
Guided IV fluids and antipyretics as needed
Oxygen to the appropriate target

Estimate clinical probability before D-dimer or imaging; in massive PE with hemodynamic collapse, thrombolysis is lifesaving.

Info

Hypoxia with no obvious cause on imaging and auscultation = pulmonary embolism until proven otherwise.

Tension pneumothorax is a clinical diagnosis, not a radiological one.

Warning

Suspected tension pneumothorax: immediate needle decompression then chest drain — never wait for the X-ray.

References

ERC Guidelines 2021 — Adult advanced life support (2021)Open source in new tab
GOLD Report 2024 — COPD diagnosis & management (2024)Open source in new tab
GINA 2024 — Global strategy for asthma management (2024)Open source in new tab
ESC Guidelines 2021 — Acute and chronic heart failure (2021)Open source in new tab

Governance & review

Author: Dr. Lina Hassan; Medical Director
Scientific review: Dr. Hassan Karim; Project Director
Last reviewed: 10 June 2026
Version: 1.0

بنية العرض مقتبسة من Notfallguru.de بموافقة فريقه — المحتوى بانتظار مراجعتهم

This content is an educational reference and does not replace clinical judgement or local protocols.

Dyspnea & Respiratory Failure

Killers — rule out first

Red flags

First steps

Clinical pearls

Prehospital

Differential diagnosis

Conditions in detail

Diagnostic workup

Therapy

Illustrative adult dosing

Therapy

Illustrative adult dosing

Therapy

CRB-65

Interpretation

Therapy

References

Governance & review

Dyspnea & Respiratory Failure

Killers — rule out first

Red flags

First steps

Clinical pearls

Prehospital

Differential diagnosis

Conditions in detail

Diagnostic workup

Therapy

Illustrative adult dosing

Therapy

Illustrative adult dosing

Therapy

CRB-65

Interpretation

Therapy

References

Governance & review

1Killers — rule out first

2Red flags

3First steps

4Clinical pearls

5Prehospital

6Differential diagnosis

7Conditions in detail

COPD exacerbation

Diagnostic workup

Therapy

Illustrative adult dosing

Acute asthma

Therapy

Illustrative adult dosing

Acute cardiogenic pulmonary edema

Therapy

Community-acquired pneumonia

CRB-65

Interpretation

Therapy

Pulmonary embolism

Pneumothorax

8References

9Governance & review

1Killers — rule out first

2Red flags

3First steps

4Clinical pearls

5Prehospital

6Differential diagnosis

7Conditions in detail

COPD exacerbation

Diagnostic workup

Therapy

Illustrative adult dosing

Acute asthma

Therapy

Illustrative adult dosing

Acute cardiogenic pulmonary edema

Therapy

Community-acquired pneumonia

CRB-65

Interpretation

Therapy

Pulmonary embolism

Pneumothorax

8References

9Governance & review

Killers — rule out first

Red flags

First steps

Clinical pearls

Prehospital

Differential diagnosis

Conditions in detail

References

Governance & review

Killers — rule out first

Red flags

First steps

Clinical pearls

Prehospital

Differential diagnosis

Conditions in detail

References

Governance & review