# Clinical Cases: Preoperative Evaluation

## Case 1: High-Risk Cardiac Patient Requiring Urgent Surgery

### Patient Demographics
- **Age:** 72 years
- **Sex:** Male
- **Occupation:** Retired construction worker

### Chief Complaint
"I have severe abdominal pain and bloating for the past day."

### History of Present Illness
The patient presents to the emergency department with a 24-hour history of progressive abdominal distension, crampy abdominal pain, nausea, and obstipation. He has not passed gas or had a bowel movement since symptoms began. He reports a history of colon cancer treated with sigmoid resection 5 years ago. He has been experiencing increasing abdominal discomfort over the past week, initially attributed to constipation.

### Past Medical History
- Coronary artery disease with myocardial infarction 8 months ago, treated with drug-eluting stents to LAD and RCA
- On dual antiplatelet therapy (aspirin and clopidogrel)
- Congestive heart failure with ejection fraction 35%
- Type 2 diabetes mellitus on insulin
- Hypertension
- Chronic kidney disease stage 3 (baseline creatinine 1.8 mg/dL)
- Sigmoid colon cancer (T3N1M0), status post sigmoid resection with primary anastomosis 5 years ago

### Medications
- Aspirin 81 mg daily
- Clopidogrel 75 mg daily
- Metoprolol 50 mg twice daily
- Lisinopril 20 mg daily
- Atorvastatin 80 mg daily
- Furosemide 40 mg daily
- Insulin glargine 30 units at bedtime
- Insulin lispro with meals

### Physical Examination
- **Vitals:** BP 148/88 mmHg, HR 98 bpm, RR 20/min, Temp 37.8C, SpO2 95% on room air
- **General:** Elderly male in moderate distress, appears uncomfortable
- **Cardiovascular:** Irregular rhythm, S1 and S2 present, no murmurs, JVP elevated to 10 cm
- **Pulmonary:** Bibasilar crackles, no wheezing
- **Abdomen:** Distended, tympanitic, diffuse tenderness without peritoneal signs, high-pitched bowel sounds, well-healed midline surgical scar
- **Extremities:** 2+ bilateral lower extremity edema

### Laboratory Results
- WBC: 12,400/uL (84% neutrophils)
- Hemoglobin: 10.2 g/dL
- Platelets: 245,000/uL
- Creatinine: 2.4 mg/dL (baseline 1.8)
- BUN: 42 mg/dL
- Glucose: 215 mg/dL
- Sodium: 134 mEq/L
- Potassium: 5.1 mEq/L
- Lactate: 2.8 mmol/L
- BNP: 890 pg/mL
- Troponin I: 0.04 ng/mL (normal <0.04)

### Imaging
- **Abdominal X-ray:** Dilated small bowel loops with multiple air-fluid levels, no free air
- **CT Abdomen/Pelvis with contrast:** Small bowel obstruction with transition point at prior surgical anastomosis site, concerning for adhesive obstruction. No evidence of strangulation or bowel wall compromise.

### Preoperative Risk Assessment

**Revised Cardiac Risk Index (RCRI):**
- High-risk surgery: +1
- History of ischemic heart disease: +1
- History of congestive heart failure: +1
- Creatinine >2 mg/dL: +1
- Insulin-dependent diabetes: +1
- **Total: 5 points** (estimated major cardiac event risk >9%)

**Functional Capacity Assessment:**
- Patient reports difficulty climbing one flight of stairs (functional capacity <4 METs)
- Limited by dyspnea and fatigue

**ASA Physical Status:** Class IV (severe systemic disease that is a constant threat to life)

### Preoperative Optimization Plan

1. **Cardiology consultation:** Emergent evaluation given high cardiac risk; recent MI and stents require careful antiplatelet management
2. **Antiplatelet management:** Continue aspirin; hold clopidogrel for 5-7 days if surgery can be delayed; if urgent surgery required, proceed with increased bleeding risk
3. **Heart failure optimization:** IV diuresis for volume overload, maintain beta-blocker
4. **Renal protection:** Avoid nephrotoxins, ensure adequate hydration, minimize contrast exposure
5. **Glycemic control:** Transition to insulin drip for perioperative glucose management
6. **Anemia workup:** Consider transfusion if hemoglobin drops below 8 g/dL
7. **Electrolyte correction:** Monitor potassium closely, correct hyperkalemia if worsens
8. **ICU bed reservation:** High likelihood of requiring postoperative intensive monitoring

### Clinical Decision
After 24 hours of nasogastric decompression, IV fluids, and bowel rest, the patient's obstruction did not resolve. Repeat CT showed persistent obstruction without signs of bowel compromise. Given the failure of conservative management and need for surgical intervention in a high-risk patient:

- Cardiology cleared patient for urgent surgery with acceptable but elevated risk
- Clopidogrel held; aspirin continued
- BNP trending down with diuresis
- Creatinine improved to 2.1 mg/dL with hydration
- Patient and family counseled extensively on risks including MI, heart failure exacerbation, renal failure, and death (estimated perioperative mortality 5-10%)

### Operative Course
Exploratory laparotomy with lysis of adhesions. Dense adhesive band identified at prior anastomotic site causing complete obstruction. Bowel viable after release. No resection required. Estimated blood loss 150 mL.

### Postoperative Course
- ICU admission for 48 hours of hemodynamic monitoring
- Troponin peaked at 0.12 ng/mL (demand ischemia, not STEMI)
- Managed with rate control and aspirin continuation
- Creatinine returned to baseline by POD 3
- Returned to floor POD 2, diet advanced POD 4
- Discharged POD 7 with close cardiology follow-up

### Clinical Image
![Preoperative ECG Assessment](case_01_image.jpg)

**Image Description:** A 12-lead electrocardiogram demonstrating findings relevant to preoperative cardiac evaluation. Assessment of rhythm, rate, and evidence of ischemia or prior infarction is essential in high-risk surgical patients.

**Attribution:** Image from Wikimedia Commons, public domain. Source: https://commons.wikimedia.org/wiki/File:ECG_12derivations.png

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## Case 2: Preoperative Optimization of Diabetic Patient

### Patient Demographics
- **Age:** 58 years
- **Sex:** Female
- **Occupation:** Office manager

### Chief Complaint
"I need surgery for a hernia that keeps getting stuck."

### History of Present Illness
The patient presents for preoperative evaluation prior to elective incisional hernia repair. She developed an incisional hernia following open cholecystectomy 3 years ago. Over the past year, the hernia has enlarged significantly and she has experienced three episodes of incarceration requiring emergency department visits for manual reduction. Her most recent episode was 2 weeks ago. She is now scheduled for elective mesh hernia repair.

### Past Medical History
- Type 2 diabetes mellitus for 15 years with HbA1c 9.2%
- Peripheral neuropathy
- Chronic kidney disease stage 2 (creatinine 1.3 mg/dL)
- Obesity (BMI 38)
- Obstructive sleep apnea on CPAP
- Former smoker (quit 6 months ago, 30 pack-year history)

### Preoperative Optimization

**Glycemic Optimization:**
- HbA1c 9.2% indicates poor glycemic control
- Goal: HbA1c <8% prior to elective surgery
- Surgery delayed 6 weeks for intensive diabetes management
- Endocrinology consultation for medication adjustment
- Patient started on GLP-1 agonist in addition to metformin
- Repeat HbA1c at 6 weeks: 7.8%

**Smoking Cessation:**
- Patient quit 6 months ago - excellent
- Mucociliary function typically recovers by 8 weeks
- Reduced wound complication risk with cessation

**Weight Optimization:**
- Discussed weight loss goals
- Referred to bariatric medicine
- Lost 8 kg over 6-week optimization period
- Reduced surgical difficulty and wound complications

**Sleep Apnea Management:**
- CPAP compliance verified
- Instructed to bring CPAP device to hospital
- Anesthesia notified for airway planning
- Postoperative continuous pulse oximetry ordered

### Outcome
Surgery performed after 6-week optimization period. Laparoscopic incisional hernia repair with mesh completed without complication. Patient discharged same day with CPAP use continued. Follow-up at 2 weeks showed well-healed incisions and no recurrence at 6 months.

### Teaching Points
1. Elective surgery allows time for preoperative optimization
2. HbA1c >8% associated with increased surgical site infections
3. Smoking cessation at any time before surgery improves outcomes
4. OSA patients require special perioperative precautions
5. Weight loss reduces technical difficulty and wound complications