A 56-year-old previously healthy woman with no other past medical history is post-operative day one from an open reduction and internal fixation of a fractured right radius and ulna after a motor vehicle accident. What is one of the primary ways of preventing postoperative pneumonia in this patient?

In-hospital intravenous antibiotics

A 76-year-old woman presents to the primary care physician for a regular check-up. History reveals that she has had episodes of mild urinary incontinence over the past 2 years precipitated by sneezing or laughing. However, over the past week, her urinary incontinence has occurred during regular activities. Her blood pressure is 140/90 mm Hg, heart rate is 86/min, respiratory rate is 22/min, and temperature is 37.7°C (99.9°F). Physical examination is remarkable for suprapubic tenderness. Urinalysis reveals 15 WBCs/HPF, positive nitrites, and positive leukocyte esterase. Which of the following is the best next step for this patient?

Ultrasound scan of the kidneys, urinary tract, and bladder

Start empirical antibiotic therapy

A general surgery intern is paged to the bedside of a 59-year-old male who underwent a successful sigmoidectomy for treatment of recurrent diverticulitis. The patient's nurse just recorded a temperature of 38.7 C, and relates that the patient is complaining of chills. The surgery was completed 8 hours ago and was complicated by extensive bleeding, with an estimated blood loss of 1,700 mL. Post-operative anemia was diagnosed after a hemoglobin of 5.9 g/dL was found; 2 units of packed red blood cells were ordered, and the transfusion was initiated 90 minutes ago. The patient's vital signs are as follows: T 38.7 C, HR 88, BP 138/77, RR 18, SpO2 98%. Physical examination does not show any abnormalities. After immediately stopping the transfusion, which of the following is the best management of this patient's condition?

Monitor patient and administer acetaminophen

Hydrate with 1 L bolus of normal saline followed by maintenance fluids at 125 cc/hr

Start supplemental oxygen by nasal cannula

Initiate broad spectrum antibiotics

A 68-year-old woman presents to the hospital for an elective right hemicolectomy. She is independently mobile and does her own shopping. She has had type 2 diabetes mellitus for 20 years, essential hypertension for 15 years, and angina on exertion for 6 years. She has a 30-pack-year history of smoking. The operation was uncomplicated. On post-op day 5, she becomes confused. She has a temperature of 38.5°C (101.3°F), respiratory rate of 28/min, and oxygen saturation of 92% on 2 L of oxygen. She is tachycardic at 118/min and her blood pressure is 110/65 mm Hg. On chest auscultation, she has coarse crackles in the right lung base. Her surgical wound appears to be healing well, and her abdomen is soft and nontender. Which of the following is the most likely diagnosis?

Multiple organ dysfunction syndrome

Non-infectious systemic inflammatory response syndrome (SIRS)

A 62-year-old man is brought to the emergency department with fatigue, dry cough, and shortness of breath for 3 days. He reports a slight fever and has also had 3 episodes of watery diarrhea earlier that morning. Last week, he attended a business meeting at a hotel and notes some of his coworkers have also become sick. He has a history of hypertension and hyperlipidemia. He takes atorvastatin, hydrochlorothiazide, and lisinopril. He appears in mild distress. His temperature is 102.1°F (38.9°C), pulse is 56/min, respirations are 16/min, and blood pressure is 150/85 mm Hg. Diffuse crackles are heard in the thorax. Examination shows a soft and nontender abdomen. Laboratory studies show: Hemoglobin 13.5 g/dL Leukocyte count 15,000/mm3 Platelet count 130,000/mm3 Serum Na+ 129 mEq/L Cl- 100 mEq/L K+ 4.6 mEq/L HCO3- 22 mEq/L Urea nitrogen 14 mg/dL Creatinine 1.3 mg/dL An x-ray of the chest shows infiltrates in both lungs. Which of the following is the most appropriate next step in diagnosis?

Direct immunofluorescent antibody test

Three days after undergoing an open cholecystectomy, a 73-year-old man has fever and abdominal pain. He has hypertension, type 2 diabetes mellitus, chronic obstructive pulmonary disease, and benign prostatic hyperplasia. He had smoked one pack of cigarettes daily for 40 years but quit 1 year ago. He does not drink alcohol. Prior to admission to the hospital, his medications included lisinopril, metformin, ipratropium, and tamsulosin. He appears acutely ill and lethargic. His temperature is 39.5°C (103.1°F), pulse is 108/min, respirations are 18/min, and blood pressure is 110/84 mm Hg. He is oriented only to person. Examination shows a 10-cm subcostal incision that appears dry and non-erythematous. Scattered expiratory wheezing is heard throughout both lung fields. His abdomen is distended with tenderness to palpation over the lower quadrants. Laboratory studies show: Hemoglobin 10.1 g/dl Leukocyte count 19,000/mm3 Serum Glucose 180 mg/dl Urea Nitrogen 25 mg/dl Creatinine 1.2 mg/dl Lactic acid 2.5 mEq/L (N = 0.5 - 2.2 mEq/L) Urine Protein 1+ RBC 1–2/hpf WBC 32–38/hpf Which of the following is the most likely underlying mechanism of this patient's current condition?

Intraabdominal abscess formation

Postoperative fever evaluation for USMLE Step 2 CK: High-Yield Surgery Lessons

Post-op Fever Causes - The 5 W's

A systematic approach to diagnosing postoperative fever based on the timing of its onset.

5 Ws of Postoperative Fever

📌 Mnemonic	Timeframe (Post-Op)	Cause	Key Findings
Wind	24-48 hrs	Atelectasis	Low-grade fever, tachypnea, decreased breath sounds.
Water	>48-72 hrs	Urinary Tract Infection (UTI)	Dysuria, frequency, urgency. Often related to Foley catheters.
Wound	>72 hrs (Day 5-7)	Surgical Site Infection (SSI)	Localized pain, erythema, warmth, purulent drainage.
Walking	>72 hrs (Day 7-10)	DVT / Pulmonary Embolism	DVT: Unilateral leg swelling, pain. PE: Pleuritic chest pain, SOB.
Wonder Drugs	Variable (>1 week)	Drug fever, blood products	Fever of unknown origin, often a diagnosis of exclusion. May see rash.

Diagnostic Workup - From Fever to Finding

Initial Steps: Thorough physical exam focusing on surgical site, lungs, abdomen, calves, and all access lines (IVs, central lines, Foley).
Core Labs & Imaging:
- CBC with differential (for leukocytosis).
- Blood cultures (x2, from separate sites).
- Urinalysis and urine culture.
- Chest X-ray, especially with pulmonary signs.

⭐ Always obtain at least two sets of blood cultures from different venipuncture sites before starting empiric antibiotics to maximize diagnostic yield.

Management Principles - Dousing the Flames

General Measures:
- Administer antipyretics (acetaminophen) for symptomatic control.
- Ensure euvolemia and correct electrolyte abnormalities.
- Remove potential sources of infection (e.g., central lines, Foley catheters) if clinically indicated.
Targeted Treatment (by cause):
- Wind (Atelectasis/Pneumonia): Aggressive pulmonary toilet, incentive spirometry. For pneumonia, start empiric antibiotics (e.g., vancomycin + piperacillin-tazobactam).
- Water (UTI): Replace catheter if still needed; start antibiotics based on local resistance patterns (e.g., ceftriaxone).
- Wound (SSI): Open wound for drainage, perform dressing changes. Add antibiotics for significant cellulitis or systemic signs.
- Walking (VTE): Initiate therapeutic anticoagulation (e.g., heparin or LMWH).
- Wonder Drugs: Discontinue the offending agent.

⭐ In a patient with a surgical abscess, source control (incision and drainage) is the most critical step and should not be delayed for antibiotic therapy alone.

Postoperative Fever Etiologies

High‑Yield Points - ⚡ Biggest Takeaways

The "5 Ws" mnemonic is crucial for timing fever: Wind, Water, Walking, Wound, Wonder Drugs.

Atelectasis (Wind) is the most frequent cause in the first 48 hours.

UTIs (Water) are common after day 3, especially with Foley catheters.

DVT/PE (Walking) is a risk around days 5-7; suspect with leg swelling or pleuritic chest pain.

Surgical site infections (Wound) typically manifest after day 7.

Drug fever is a diagnosis of exclusion; an abscess is a late cause requiring a CT scan.

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