# Clinical Cases: Approach to the Undifferentiated Patient

## Case 1: The "Sick" Patient - Rapid Primary Survey Saves a Life

### Patient Demographics
- **Age:** 58 years
- **Sex:** Male
- **Occupation:** Truck driver

### Chief Complaint
"I don't feel right."

### History of Present Illness
EMS brings a 58-year-old male found slumped in his cab at a truck stop. Bystander called 911 after noticing him unresponsive for "a few minutes." On EMS arrival, patient was lethargic with weak pulse. Limited history available - coworker reports patient complained of chest discomfort earlier in the day.

### Initial Assessment (Triage and First Impression)

**ESI Level:** 1 - Immediate life-saving intervention required

**First Impression (Across the Room):**
- Appearance: Pale, diaphoretic, obtunded
- Work of breathing: Shallow respirations
- Circulation: Mottled extremities, cool skin

**Vital Signs:**
- Heart rate: 42 bpm, irregular
- Blood pressure: 78/50 mmHg
- Respiratory rate: 8 breaths/min
- SpO2: 88% on room air
- Temperature: 36.1C
- GCS: 10 (E2V4M4)

### Primary Survey (ABCDE)

**Airway:**
- Patent but tenuous due to altered mental status
- No stridor or obstruction
- Jaw thrust performed, improved air exchange

**Breathing:**
- Shallow, slow respirations
- Clear bilateral breath sounds
- No accessory muscle use (concerning - may indicate fatigue)
- Bag-valve-mask ventilation initiated

**Circulation:**
- Weak central pulses, absent peripheral pulses
- Capillary refill >5 seconds
- No external hemorrhage
- Two large-bore IVs placed
- 12-lead ECG obtained immediately

**Disability:**
- GCS 10 (E2V4M4)
- Pupils: 4mm, sluggishly reactive bilaterally
- Glucose: 142 mg/dL
- Moving all extremities, no focal deficits noted

**Exposure:**
- Cool, clammy skin
- No trauma, rashes, or obvious abnormalities
- Warm blankets applied

### Resuscitation Priorities

**Immediate Interventions:**
1. High-flow oxygen via BVM
2. IV access x2 (18-gauge)
3. Continuous cardiac monitoring
4. 12-lead ECG STAT

**ECG Findings:**
- Third-degree AV block with ventricular escape rhythm at 38 bpm
- ST elevation in leads II, III, aVF (inferior STEMI)

**Working Diagnosis:**
Cardiogenic shock secondary to inferior STEMI with complete heart block

### Secondary Survey

**SAMPLE History (from coworker):**
- Symptoms: Chest pressure this morning, "didn't think it was serious"
- Allergies: None known
- Medications: Metformin, lisinopril
- Past Medical History: Type 2 diabetes, hypertension
- Last Meal: Coffee 2 hours ago
- Events: Complained of chest discomfort, then became unresponsive

**Focused Physical Examination:**
- Neck: JVD present, no bruits
- Cardiac: Bradycardic, no murmurs
- Lungs: Clear, no crackles
- Abdomen: Soft, non-tender
- Extremities: Cool, mottled, no edema

### Diagnostic Testing

**Point-of-Care:**
- Lactate: 6.2 mmol/L (elevated - tissue hypoperfusion)
- Troponin: Pending (treatment not delayed)
- ABG: pH 7.28, pCO2 32, pO2 68, HCO3 16

**Labs:**
- CBC: WBC 12.4, Hgb 14.2, Plt 245
- BMP: Na 138, K 5.1, Cr 1.8
- Initial troponin: 2.4 ng/mL (elevated)

### Management

**Immediate Treatment:**
1. Atropine 1mg IV - no response to heart block
2. Transcutaneous pacing initiated - capture at 80mA
3. Dopamine infusion started for blood pressure support
4. Aspirin 325mg given (crushed, via NG)
5. Heparin bolus administered
6. Emergent cardiology consultation

**Disposition:**
- Cardiac catheterization lab activated
- Successful PCI to RCA with stent placement
- Temporary transvenous pacemaker placed
- ICU admission

### Teaching Points

1. **The "sick" gestalt:** This patient's vague complaint of "not feeling right" combined with abnormal appearance triggered immediate high-acuity response
2. **Primary survey saves lives:** Systematic ABCDE approach identified cardiogenic shock requiring immediate intervention
3. **ECG within 10 minutes:** Door-to-ECG time is critical - identified STEMI and complete heart block
4. **Shock classification guides treatment:** Cardiogenic shock requires different approach than hypovolemic - cautious fluids, focus on underlying cause
5. **Clinical decision-making under uncertainty:** Treatment began before definitive diagnosis based on clinical picture

### Clinical Image
![Third Degree Heart Block with Inferior STEMI](case_01_image.jpg)

**Image Description:** 12-lead ECG demonstrating third-degree atrioventricular block with slow ventricular escape rhythm and ST-segment elevation in leads II, III, and aVF consistent with inferior STEMI.

**Attribution:** Image from Wikimedia Commons, ECG demonstrating complete heart block. Licensed under CC BY-SA 4.0. Source: https://commons.wikimedia.org/wiki/File:Complete_heart_block.png

---

## Case 2: Systematic Secondary Survey Reveals Occult Pathology

### Patient Demographics
- **Age:** 72 years
- **Sex:** Female
- **Occupation:** Retired teacher

### Chief Complaint
"I'm just so weak, I can barely stand up."

### History of Present Illness
A 72-year-old woman is brought by her daughter for progressive weakness over 3 days. She has been unable to care for herself and has had poor oral intake. Daughter notes patient has been "confused" and not acting like herself.

### Initial Assessment

**ESI Level:** 2 - High-risk situation requiring urgent evaluation

**First Impression:**
- Appearance: Frail, lethargic, responds slowly
- Work of breathing: Normal respiratory effort
- Circulation: Pale skin, dry mucous membranes

**Vital Signs:**
- Heart rate: 102 bpm, regular
- Blood pressure: 92/58 mmHg
- Respiratory rate: 22 breaths/min
- SpO2: 94% on room air
- Temperature: 38.4C (101.1F)
- GCS: 14 (E4V4M6)

### Primary Survey

**Airway:** Patent, speaking in sentences
**Breathing:** Tachypneic but no distress, lungs with crackles at right base
**Circulation:** Tachycardic, weak peripheral pulses, dry mucous membranes
**Disability:** Oriented to person only, no focal deficits, glucose 168
**Exposure:** No rashes, skin turgor decreased

### Secondary Survey

**SAMPLE History:**
- Symptoms: Weakness, confusion, decreased appetite, "burning with urination" 5 days ago
- Allergies: Penicillin (rash)
- Medications: Amlodipine, atorvastatin, metformin
- PMH: HTN, hyperlipidemia, type 2 DM
- Last Meal: "A few bites" yesterday
- Events: Progressive decline over several days

**OPQRST for Weakness:**
- Onset: Gradual, 3-4 days
- Provocation: Worse with standing
- Quality: Generalized, "no energy"
- Radiation: N/A
- Severity: Unable to perform ADLs
- Timing: Progressive

**Comprehensive Physical Examination:**

**Head/Neck:**
- No meningismus
- No JVD
- Dry mucous membranes

**Cardiovascular:**
- Tachycardic, regular
- No murmurs
- Weak peripheral pulses

**Pulmonary:**
- Crackles at right base
- No wheezes

**Abdominal:**
- Soft, mild suprapubic tenderness
- No guarding or rebound
- Normoactive bowel sounds

**Genitourinary:**
- Foley placed - cloudy, foul-smelling urine

**Extremities:**
- No edema
- Decreased skin turgor

**Neurological:**
- Oriented x1 (baseline per daughter: fully oriented)
- No focal deficits
- Moving all extremities symmetrically

### Differential Diagnosis (VITAMINS Approach)

- **V**ascular: Unlikely given gradual onset
- **I**nfectious: UTI progressing to urosepsis - HIGH SUSPICION
- **T**oxic/Metabolic: Dehydration, electrolyte abnormality
- **A**utoimmune: Less likely
- **M**etabolic: DKA, HHS possible
- **I**atrogenic: Medication effect
- **N**eoplastic: Less likely for acute presentation
- **S**eizure: No witnessed seizure activity

### Diagnostic Testing

**Point-of-Care:**
- Lactate: 4.1 mmol/L (elevated)
- Glucose: 168 mg/dL

**Urinalysis:**
- Positive leukocyte esterase
- Positive nitrites
- >100 WBC/hpf
- Bacteria present

**Labs:**
- WBC: 18.2 with 88% neutrophils, 12% bands
- Cr: 2.1 (baseline 0.9)
- BUN: 42
- Na: 131, K: 5.4

**Imaging:**
- Chest X-ray: Right lower lobe infiltrate (aspiration vs. early pneumonia)
- CT Abdomen/Pelvis: Pyelonephritis changes, no abscess

### Diagnosis

**Sepsis secondary to complicated urinary tract infection (pyelonephritis)** with:
- Acute kidney injury
- Possible aspiration pneumonia
- Altered mental status (septic encephalopathy)

### Management

**Hour-1 Bundle:**
1. Lactate: 4.1 (remeasure in 2-4 hours)
2. Blood cultures x2 drawn before antibiotics
3. Broad-spectrum antibiotics: Ceftriaxone 2g IV + Azithromycin 500mg IV
4. 30 mL/kg crystalloid bolus (1.5L for 50kg patient)
5. Reassess perfusion status

**Response to Resuscitation:**
- After 2L NS: BP 108/68, HR 88
- Repeat lactate: 2.8 mmol/L (improving)
- Mental status improving

**Disposition:**
- Admitted to medical floor with sepsis protocol
- Continued antibiotics, hydration
- Daily reassessment

### Teaching Points

1. **Atypical presentations in elderly:** Weakness and confusion may be the only signs of serious infection
2. **Secondary survey thoroughness:** Suprapubic tenderness and UA findings identified the source
3. **Sepsis recognition:** qSOFA score (altered mental status, tachypnea, hypotension) prompted sepsis bundle
4. **Response to resuscitation:** Improvement in vital signs and lactate indicated adequate initial resuscitation
5. **Disposition based on trajectory:** Clinical improvement allowed floor admission vs. ICU

### Clinical Image
![Chest X-ray with Right Lower Lobe Infiltrate](case_02_image.jpg)

**Image Description:** Portable chest radiograph demonstrating a right lower lobe infiltrate consistent with pneumonia, likely aspiration-related in setting of altered mental status.

**Attribution:** Image from Radiopaedia.org, Case courtesy of Dr. Henry Knipe. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/right-lower-lobe-pneumonia