# Clinical Cases: Respiratory Emergencies

## Case 1: Massive Pulmonary Embolism

### Patient Demographics
- **Age:** 42 years
- **Sex:** Female
- **Occupation:** Accountant

### Chief Complaint
"I suddenly can't breathe and I feel like I'm going to die."

### History of Present Illness
A 42-year-old female presents with acute onset of severe dyspnea that began 30 minutes ago while at her desk at work. She describes sudden shortness of breath, chest tightness, and a feeling of impending doom. She had a 10-hour flight from Europe 5 days ago and has been on oral contraceptives for 15 years. She denies cough, hemoptysis, fever, or leg pain/swelling.

### Initial Assessment

**ESI Level:** 1 - Hemodynamically unstable

**Vital Signs:**
- Heart rate: 128 bpm
- Blood pressure: 78/52 mmHg
- Respiratory rate: 32 breaths/min
- SpO2: 82% on room air
- Temperature: 37.1C

**First Impression:**
- Acutely distressed, tripod positioning
- Cyanotic lips
- Diaphoretic
- Speaks in single words

### Physical Examination

**Cardiovascular:**
- Tachycardic, regular rhythm
- Loud P2 (pulmonic component)
- JVD present
- Cool extremities

**Pulmonary:**
- Tachypneic with accessory muscle use
- Clear breath sounds bilaterally
- No wheezes, crackles, or rhonchi

**Extremities:**
- Left calf mildly swollen
- No cord palpable
- Negative Homan's sign (unreliable)

### Clinical Decision Rules

**Wells Score for PE:**
- Clinical signs of DVT: +3
- PE most likely diagnosis: +3
- Heart rate >100: +1.5
- Immobilization/surgery: 0
- Previous DVT/PE: 0
- Hemoptysis: 0
- Malignancy: 0
- **Total: 7.5 (High probability)**

**Note:** PERC rule not applicable - high clinical probability

### Diagnostic Evaluation

**ECG:**
- Sinus tachycardia at 128 bpm
- S1Q3T3 pattern (classic but not sensitive)
- Right axis deviation
- Right ventricular strain pattern (T-wave inversions V1-V4)

**ABG (on 15L non-rebreather):**
- pH: 7.48
- pCO2: 28 mmHg
- pO2: 58 mmHg
- HCO3: 22 mEq/L
- A-a gradient: 55 (markedly elevated)

**Bedside Echocardiography:**
- Right ventricular dilation (RV:LV >1:1)
- Septal flattening ("D-sign")
- McConnell's sign (RV free wall akinesis with apical sparing)
- Moderate tricuspid regurgitation
- Estimated RVSP: 55 mmHg

**CT Pulmonary Angiography:**
- Saddle embolus at main pulmonary artery bifurcation
- Additional emboli in bilateral lower lobe arteries
- RV/LV ratio 1.4 (RV strain)

### Diagnosis

**Massive (High-Risk) Pulmonary Embolism** with:
- Hemodynamic instability (SBP <90)
- Right ventricular dysfunction
- Evidence of DVT (provoked by OCP + long-haul flight)

### Management

**Risk Stratification:**
- Massive PE (hemodynamic instability) = highest risk
- Thrombolysis indicated

**Immediate Treatment:**
1. High-flow oxygen via non-rebreather
2. IV access x2, fluid bolus 500mL (cautiously)
3. Unfractionated heparin bolus 80 units/kg
4. Vasopressor support with norepinephrine

**Systemic Thrombolysis:**
- Alteplase 100mg IV over 2 hours
- BP improved to 102/68 after 30 minutes
- SpO2 improved to 94% on 6L NC

**Post-Thrombolysis:**
- Heparin infusion restarted (no bolus)
- Transitioned to DOAC (rivaroxaban) after 5 days
- OCP discontinued permanently

### Hospital Course

**Repeat Echo (48 hours):**
- Normalized RV size and function
- RVSP: 35 mmHg

**Lower Extremity Ultrasound:**
- Acute DVT in left popliteal vein

**Discharge:**
- Rivaroxaban 15mg BID x21 days, then 20mg daily
- Duration: Minimum 3 months, consider extended given provoked PE
- Hypercoagulability workup as outpatient

### Teaching Points

1. **Hypoxia out of proportion to exam:** Clear lungs with severe hypoxemia = think PE
2. **Massive PE = thrombolysis:** Hemodynamic instability is the indication
3. **Bedside echo for risk stratification:** RV dysfunction guides treatment urgency
4. **CT-PA is gold standard:** But don't delay treatment in unstable patients
5. **Anticoagulation timing:** Start heparin BEFORE CT if high clinical suspicion

### Clinical Image
![CT Pulmonary Angiography Saddle Embolus](case_01_image.jpg)

**Image Description:** CT pulmonary angiography demonstrating a large saddle pulmonary embolus at the bifurcation of the main pulmonary artery with extension into bilateral pulmonary arteries.

**Attribution:** Image from Radiopaedia.org, Case courtesy of Dr. Matt Skalski. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/saddle-pulmonary-embolism

---

## Case 2: Severe Asthma Exacerbation with Impending Respiratory Failure

### Patient Demographics
- **Age:** 28 years
- **Sex:** Male
- **Occupation:** Graduate student

### Chief Complaint
"I can't breathe... my inhaler... isn't working."

### History of Present Illness
A 28-year-old male with history of severe persistent asthma presents with progressive dyspnea over 6 hours. He has been using his rescue inhaler "every 20 minutes" without relief. He had an upper respiratory infection 3 days ago. He was intubated for asthma 2 years ago. Currently unable to speak in full sentences.

### Initial Assessment

**ESI Level:** 1 - Impending respiratory failure

**Vital Signs:**
- Heart rate: 132 bpm
- Blood pressure: 142/88 mmHg
- Respiratory rate: 36 breaths/min
- SpO2: 88% on room air
- Peak flow: Unable to perform

**First Impression:**
- Tripod position
- Severe respiratory distress
- Speaking single words between gasps
- Diaphoretic, exhausted appearance

### Physical Examination

**Pulmonary:**
- Severe accessory muscle use
- Paradoxical abdominal breathing (concerning)
- Bilateral diffuse expiratory wheezes
- Prolonged expiratory phase
- **OMINOUS:** Decreasing breath sounds ("silent chest" developing)

**Cardiovascular:**
- Tachycardic
- Pulsus paradoxus: 18 mmHg

**Mental Status:**
- Alert but anxious
- Difficulty following commands (fatigue)

### Severity Assessment

**Signs of Impending Respiratory Failure:**
- Previous intubation (major risk factor)
- Unable to speak in sentences
- Exhaustion/fatigue
- Decreasing air movement despite effort
- Paradoxical breathing
- Altered mental status (developing)

### Management

**Immediate Treatment (concurrent, not sequential):**

1. **Continuous nebulized albuterol** (10-15mg/hour)
2. **Ipratropium bromide** 0.5mg nebulized (first 3 doses)
3. **IV methylprednisolone** 125mg
4. **Magnesium sulfate** 2g IV over 20 minutes
5. **Heliox** 70:30 initiated (if available)
6. **IV access x2**
7. **Prepare for intubation** (ketamine, succinylcholine at bedside)

**Response at 30 minutes:**
- Slight improvement: SpO2 91% on high-flow
- Still severe distress
- Peak flow: 90 L/min (15% predicted)

**BiPAP Trial:**
- Settings: IPAP 12, EPAP 5
- Patient cooperative
- SpO2 improved to 94%
- Respiratory rate decreased to 28
- Visible reduction in accessory muscle use

**Response at 60 minutes:**
- Significant improvement
- Speaking in short phrases
- Peak flow: 180 L/min (30% predicted)

### Arterial Blood Gas (60 minutes)

- pH: 7.34
- pCO2: 48 mmHg
- pO2: 72 mmHg
- HCO3: 24 mEq/L

**Note:** Normalizing CO2 in severe asthma can indicate fatigue - but clinical picture improving

### Continued Management

**Hours 2-4:**
- Continuous nebs transitioned to q1h nebs
- BiPAP weaned to nasal cannula
- Repeat steroids: Prednisone 60mg PO
- Peak flow improved to 320 L/min (55% predicted)

**Disposition:**
- Admitted to step-down unit (prior intubation = high risk)
- Continued bronchodilators and steroids
- Peak flow monitoring q4h
- Pulmonology consultation for outpatient follow-up

### Discharge (Day 3)

**Medications:**
- Prednisone 40mg daily x5 days
- Albuterol MDI with spacer PRN
- Budesonide/formoterol (controller) - uptitrated

**Education:**
- Asthma action plan reviewed
- Peak flow meter prescribed
- Follow-up in 1 week

### Teaching Points

1. **Prior intubation = high risk:** These patients can decompensate rapidly
2. **Silent chest is ominous:** Indicates severe obstruction, not improvement
3. **Continuous nebs in severe exacerbation:** Don't wait between treatments
4. **Magnesium for severe asthma:** IV MgSO4 provides additional bronchodilation
5. **BiPAP before intubation:** Can often avoid intubation if patient cooperative
6. **Normal CO2 in acute asthma is concerning:** Usually hyperventilate; normal suggests fatigue
7. **Ketamine for intubation:** Bronchodilatory properties make it ideal for asthmatic patients

### Clinical Image
![Chest X-ray Hyperinflation in Asthma](case_02_image.jpg)

**Image Description:** Chest radiograph demonstrating hyperinflated lung fields with flattened diaphragms, consistent with severe obstructive lung disease (acute asthma exacerbation).

**Attribution:** Image from Radiopaedia.org, Case courtesy of Dr. Jeremy Jones. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/asthma-exacerbation-chest-radiograph

---

## Case 3: Tension Pneumothorax

### Patient Demographics
- **Age:** 22 years
- **Sex:** Male
- **Occupation:** College athlete

### Chief Complaint
"Sudden chest pain and I can't breathe."

### History of Present Illness
A 22-year-old tall, thin male basketball player develops sudden onset of right-sided chest pain and severe dyspnea during practice. The pain is sharp, pleuritic, and he feels like he "can't get enough air." No trauma occurred. He has never had this before. He is a non-smoker.

### Initial Assessment

**ESI Level:** 1 - Critical, rapidly deteriorating

**Vital Signs (initial):**
- Heart rate: 124 bpm
- Blood pressure: 102/68 mmHg
- Respiratory rate: 36 breaths/min
- SpO2: 84% on room air

**Vital Signs (5 minutes later):**
- Heart rate: 140 bpm
- Blood pressure: 74/50 mmHg
- Respiratory rate: 40 breaths/min
- SpO2: 78%
- Patient becoming confused

### Physical Examination

**Pulmonary:**
- Severe respiratory distress
- **Absent breath sounds on right**
- **Hyperresonance to percussion on right**
- Trachea deviating to left (late sign)

**Cardiovascular:**
- Tachycardic
- **Distended neck veins** (JVD)
- Weak peripheral pulses

### Clinical Diagnosis

**TENSION PNEUMOTHORAX**

**Classic findings present:**
- Absent breath sounds (affected side)
- Hyperresonance (affected side)
- Hypotension (obstructive shock)
- JVD (impaired venous return)
- Tracheal deviation (late sign - toward unaffected side)

**This is a CLINICAL diagnosis - do NOT delay for imaging**

### Management

**Immediate Needle Decompression:**
- 14-gauge angiocatheter
- Location: 2nd intercostal space, midclavicular line, RIGHT side
- Above the rib (avoid neurovascular bundle)
- Rush of air heard - immediate improvement

**Post-Decompression Vitals:**
- BP: 98/62 mmHg
- HR: 110 bpm
- SpO2: 92% on high-flow O2
- Mental status improved

**Tube Thoracostomy (Chest Tube):**
- Location: 5th intercostal space, anterior axillary line (triangle of safety)
- 28 French chest tube inserted
- Connected to water seal/suction at -20 cm H2O
- Large air leak noted initially

### Imaging

**Chest X-ray (post-chest tube):**
- Chest tube in good position
- Lung re-expanded
- Small residual apical pneumothorax
- No effusion

### Hospital Course

- Air leak resolved by day 2
- Chest tube removed day 3
- Follow-up CXR: Complete resolution
- Discharged day 4

### Discussion with Patient

**Primary Spontaneous Pneumothorax:**
- Common in tall, thin young males
- Often due to rupture of apical blebs
- Recurrence risk: 30% within 5 years
- Smoking would significantly increase risk

**Activity Restrictions:**
- No flying for 2 weeks after resolution
- No scuba diving (permanent consideration)
- Sports: Can resume after 2-3 weeks if asymptomatic

**Return Precautions:**
- Sudden chest pain or dyspnea = return immediately
- May need surgical pleurodesis if recurrent

### Teaching Points

1. **Tension pneumothorax is a CLINICAL diagnosis:** Don't wait for CXR
2. **Needle decompression is temporizing:** Must be followed by chest tube
3. **Remember the anatomy:** 2nd ICS midclavicular OR 4th-5th ICS anterior axillary
4. **Absent breath sounds + hemodynamic instability = decompress immediately**
5. **Primary spontaneous pneumothorax:** Think tall, thin, young males
6. **Bedside ultrasound:** Absent lung sliding can rapidly confirm pneumothorax

### Clinical Image
![Tension Pneumothorax Chest X-ray](case_03_image.jpg)

**Image Description:** Chest radiograph demonstrating a large right-sided tension pneumothorax with complete lung collapse, mediastinal shift to the left, and depression of the right hemidiaphragm.

**Attribution:** Image from Wikimedia Commons, Chest X-ray showing tension pneumothorax. Licensed under CC BY-SA 3.0. Source: https://commons.wikimedia.org/wiki/File:Tension_pneumothorax_chest_X-ray.jpg