# Clinical Cases: Surgical Emergencies

## Case 1: Small Bowel Obstruction with Strangulation

### Patient Presentation
**Demographics:** 68-year-old female

**Chief Complaint:** Severe abdominal pain, nausea, and vomiting for 12 hours

**History of Present Illness:**
Mrs. Patterson presents to the emergency department with acute onset of severe, crampy abdominal pain that began 12 hours ago. She has had multiple episodes of bilious vomiting and has not passed gas or stool since symptom onset. The pain has become constant over the past 4 hours and is now localized to the left lower quadrant. She has a history of open hysterectomy 15 years ago for uterine fibroids.

**Past Medical History:**
- Hypertension
- Type 2 diabetes mellitus (on metformin)
- Hyperlipidemia
- Prior abdominal surgery (TAH-BSO, 2009)

**Physical Examination:**
- Vitals: T 38.4C, HR 118, BP 98/62, RR 22, SpO2 96% RA
- General: Appears distressed, diaphoretic
- Abdomen: Distended, tympanic, diffuse tenderness with focal peritoneal signs in left lower quadrant, well-healed Pfannenstiel scar
- Bowel sounds: High-pitched, hyperactive

**Laboratory Studies:**
- WBC: 18,200 with left shift (85% neutrophils)
- Lactate: 4.8 mmol/L (elevated)
- BUN/Cr: 28/1.4 (baseline 1.0)
- Glucose: 245 mg/dL
- Lipase: Normal

### Clinical Questions

1. **What imaging study should be ordered, and what findings would you expect?**

   **Recommended Imaging:** CT abdomen/pelvis with IV contrast (oral contrast optional given clinical picture)

   **Expected Findings in SBO:**
   | Finding | Significance |
   |---------|--------------|
   | Dilated small bowel (>3cm) | Confirms obstruction |
   | Transition point | Identifies location of obstruction |
   | Small bowel feces sign | Suggests complete obstruction |
   | Decompressed distal bowel | Confirms complete obstruction |

   **Findings Concerning for Strangulation:**
   | Finding | Significance |
   |---------|--------------|
   | Closed-loop configuration | Two adjacent transition points - HIGH RISK |
   | Bowel wall thickening | Suggests edema/ischemia |
   | Mesenteric haziness | Inflammatory changes |
   | Reduced/absent wall enhancement | Suggests ischemia |
   | Pneumatosis intestinalis | Air in bowel wall - LATE FINDING |
   | Portal venous gas | OMINOUS - indicates necrosis |

   **This patient's CT shows:** Closed-loop obstruction in the left lower quadrant with a transition point at a band adhesion, surrounding mesenteric stranding, and reduced enhancement of the involved segment consistent with strangulated small bowel obstruction.

2. **This patient has signs concerning for strangulation. What are the clinical indicators of strangulation in SBO?**

   **Clinical Signs of Strangulation:**

   | Category | Finding | Present in This Patient |
   |----------|---------|------------------------|
   | Vital signs | Tachycardia, hypotension | Yes - HR 118, BP 98/62 |
   | Pain | Constant (not colicky), severe | Yes - became constant |
   | Exam | Focal peritoneal signs | Yes - LLQ peritonitis |
   | Fever | Temperature >38C | Yes - 38.4C |
   | Labs | Elevated lactate | Yes - 4.8 |
   | Labs | Leukocytosis | Yes - 18,200 |
   | Labs | Metabolic acidosis | Check ABG |

   **Assessment:** Multiple clinical indicators suggest strangulation - this patient requires EMERGENT surgical intervention.

3. **What are the key differences between operative and non-operative management of SBO?**

   **Management Algorithm:**

   | Feature | Non-Operative Management | Operative Management |
   |---------|-------------------------|---------------------|
   | Obstruction type | Partial | Complete |
   | Signs of strangulation | Absent | Present |
   | Closed-loop | No | Yes |
   | Peritoneal signs | No | Yes |
   | Prior response | History of resolving with conservative Rx | First presentation or failed conservative |
   | Time limit | 48-72 hours trial | Immediate if strangulated |

   **Non-Operative Management Components:**
   - NPO status
   - Nasogastric tube decompression
   - IV fluid resuscitation
   - Serial abdominal exams (q4-6h)
   - Water-soluble contrast study (Gastrografin) - both diagnostic and therapeutic

   **This Patient:** Meets criteria for emergent surgery due to signs of strangulation.

4. **Outline your surgical consultation and communication with the OR team.**

   **Structured Surgical Consultation (SBAR format):**

   **Situation:** "I am the sub-intern caring for Mrs. Patterson in the ED. She has a strangulated small bowel obstruction requiring emergent surgical intervention."

   **Background:** "68-year-old female with prior TAH-BSO presenting with 12 hours of SBO symptoms. CT shows closed-loop obstruction with signs of strangulation."

   **Assessment:** "Clinical picture of strangulation - tachycardia, hypotension, fever, peritoneal signs, lactate 4.8, leukocytosis."

   **Recommendation:** "Patient needs emergent exploratory laparotomy. I have obtained consent, type and screen is sent, and she has large-bore IV access. Blood bank is aware. She is currently receiving volume resuscitation."

   **OR Communication Checklist:**
   - [ ] Notify charge nurse of emergent case
   - [ ] Confirm equipment: laparotomy tray, bowel resection instruments, stapler available
   - [ ] Anesthesia aware of hemodynamic status and aspiration risk
   - [ ] Blood products: Type and crossmatch 2 units pRBC
   - [ ] Antibiotic timing: Administer within 60 minutes of incision

### Clinical Image

![Upright X-ray demonstrating small bowel obstruction](case_01_image.jpg)

*Image: Upright abdominal radiograph demonstrating multiple dilated loops of small bowel with air-fluid levels consistent with small bowel obstruction. The presence of multiple air-fluid levels at different heights within the same loop (differential air-fluid levels) suggests complete obstruction. Source: Wikimedia Commons.*

**Image Attribution:** Upright X-ray demonstrating small bowel obstruction. Wikimedia Commons. Public Domain.
**URL:** https://commons.wikimedia.org/wiki/File:Upright_X-ray_demonstrating_small_bowel_obstruction.jpg

---

## Case 2: Ruptured Abdominal Aortic Aneurysm

### Patient Presentation
**Demographics:** 74-year-old male

**Chief Complaint:** Sudden onset severe back pain

**History of Present Illness:**
Mr. Thompson is a 74-year-old male brought by EMS with sudden onset of severe back pain that began 45 minutes ago while he was gardening. He describes the pain as "tearing" in nature, radiating from his mid-back to his left flank. He felt lightheaded and nearly lost consciousness shortly after the pain began. EMS reports his blood pressure was 78/50 in the field but improved to 92/60 after 1 liter of normal saline.

**Past Medical History:**
- Known 5.8 cm infrarenal AAA (last surveillance 6 months ago)
- Hypertension (poorly controlled)
- 50 pack-year smoking history
- COPD
- Coronary artery disease (prior MI, 3 years ago)

**Physical Examination:**
- Vitals: T 36.2C, HR 124, BP 88/52, RR 28, SpO2 94% on 4L NC
- General: Pale, diaphoretic, appearing acutely ill
- Cardiovascular: Tachycardic, distant heart sounds
- Abdomen: Mildly distended, palpable pulsatile mass in epigastrium, diffuse tenderness
- Extremities: Mottled bilateral lower extremities, diminished femoral pulses
- Mental status: Confused, answering questions inappropriately

### Clinical Questions

1. **What is your immediate differential diagnosis, and how do you prioritize evaluation?**

   **Differential Diagnosis for Sudden Severe Back Pain + Hypotension:**
   | Diagnosis | Key Features | Probability |
   |-----------|--------------|-------------|
   | **Ruptured AAA** | Known AAA, pulsatile mass, shock | HIGH |
   | Aortic dissection | Tearing pain, pulse deficit | Consider |
   | Acute MI | Prior CAD, but pain atypical | Less likely |
   | Acute pancreatitis | No risk factors provided | Less likely |
   | Perforated viscus | Usually peritoneal signs | Less likely |

   **Critical Point:** In a hemodynamically UNSTABLE patient with known AAA presenting with this clinical picture, the diagnosis of ruptured AAA is presumed. **Do NOT delay for CT scan** - patient should go directly to OR.

2. **Describe the initial resuscitation strategy for ruptured AAA.**

   **Damage Control Resuscitation Principles:**

   | Component | Target | Rationale |
   |-----------|--------|-----------|
   | **Permissive hypotension** | SBP 70-90 mmHg | Higher pressure increases ongoing hemorrhage |
   | **Massive transfusion protocol** | Activate immediately | 1:1:1 ratio pRBC:FFP:platelets |
   | **Limit crystalloid** | 1-2L maximum | Dilutional coagulopathy, hypothermia |
   | **Maintain temperature** | >35C | Prevent lethal triad |
   | **Tranexamic acid** | 1g IV | Consider if available |

   **Immediate Actions:**
   1. Two large-bore IVs (14-16 gauge)
   2. Type and crossmatch 6 units pRBC STAT
   3. Activate massive transfusion protocol
   4. Call vascular surgery immediately
   5. Alert OR that patient is coming NOW
   6. Hold off on aggressive fluid resuscitation

3. **The vascular surgeon is 15 minutes away. What should you be doing during this time?**

   **Sub-Intern Responsibilities While Awaiting Surgeon:**

   | Task | Action |
   |------|--------|
   | Airway | Maintain current status; prepare for RSI if mental status declines |
   | Access | Ensure 2 large-bore IVs, consider placing arterial line |
   | Blood | Confirm blood bank has MTP activated, O-negative blood available |
   | Consent | Obtain emergent consent from patient or family (telephone consent if needed) |
   | Documentation | Document timeline of events, vitals, interventions |
   | Communication | Keep family informed of critical nature |
   | OR preparation | Confirm OR is ready, equipment available (cell saver, warming devices) |

   **Do NOT:**
   - Leave patient unattended
   - Delay for additional imaging if unstable
   - Over-resuscitate with crystalloid

4. **What are the key prognostic factors for ruptured AAA?**

   **Prognostic Factors Affecting Survival:**

   | Factor | Better Prognosis | Worse Prognosis |
   |--------|------------------|-----------------|
   | Hemodynamic status | Stable or responds to resuscitation | Refractory shock |
   | Mental status | Alert | Obtunded/unconscious |
   | Time to OR | <60 minutes from rupture | Prolonged delay |
   | Age | <70 years | >80 years |
   | Comorbidities | Minimal | Significant cardiac/renal disease |
   | Cardiac arrest | No | Pre-operative CPR |

   **Overall Statistics:**
   - Ruptured AAA mortality: ~50% (even with repair)
   - Elective AAA repair mortality: 1-2%
   - This contrast emphasizes the importance of surveillance and elective repair

### Clinical Image

![CT showing ruptured AAA](case_02_image.jpg)

*Image: CT angiography demonstrating a ruptured infrarenal abdominal aortic aneurysm with retroperitoneal hematoma. The contrast extravasation indicates active hemorrhage. In hemodynamically unstable patients, CT should not delay operative intervention. Source: Wikimedia Commons.*

**Image Attribution:** Abdominal aortic aneurysm CT. Wikimedia Commons. CC BY-SA 3.0.
**URL:** https://commons.wikimedia.org/wiki/File:Aortic_aneurysm_CT.jpg

---

## Summary Points

1. **Small Bowel Obstruction Classification:** Differentiate partial vs. complete, simple vs. strangulated, and closed-loop configurations - each determines management urgency

2. **Strangulation Signs:** Constant pain, focal peritoneal signs, fever, tachycardia, elevated lactate, and leukocytosis indicate bowel compromise requiring emergent surgery

3. **SBO Management Decision:** Non-operative trial (48-72 hours) is appropriate for partial obstruction without strangulation; complete obstruction with strangulation requires immediate surgery

4. **Ruptured AAA Recognition:** Classic triad of hypotension, back/abdominal pain, and pulsatile mass - but all three present in minority of cases; maintain high suspicion

5. **Permissive Hypotension:** In hemorrhagic shock from ruptured AAA, target SBP 70-90 mmHg to prevent exacerbation of bleeding while maintaining minimal vital organ perfusion

6. **Massive Transfusion:** Activate MTP early; use balanced 1:1:1 blood product ratios; limit crystalloid to prevent dilutional coagulopathy

7. **Time-Critical Decisions:** Unstable patients with presumed surgical emergency proceed to OR without waiting for confirmatory imaging

8. **Communication:** Use structured approaches (SBAR) for surgical consultation; clear communication with OR, blood bank, and family is essential