A 60-year-old rock musician presents to the office because he has been feeling increasingly tired for the past 6 months. He has a history of intravenous drug use and alcohol abuse. He states that he feels quite tired, but he otherwise has no complaints. Physical examination is noncontributory. His laboratory values are normal other than moderately elevated liver enzymes. Which of the following additional tests should you order first?

Hepatitis E virus-specific IgM antibodies

Hepatitis D virus-specific IgG antibody

Hepatitis A virus-specific IgM antibodies

A 65-year-old man presents to his primary care physician for a pre-operative evaluation. He is scheduled for cataract surgery in 3 weeks. His past medical history is notable for diabetes, hypertension, and severe osteoarthritis of the right knee. His medications include metformin, hydrochlorothiazide, lisinopril, and aspirin. His surgeon ordered blood work 1 month ago, which showed a hemoglobin of 14.2 g/dL, INR of 1.2, and a hemoglobin A1c of 6.9%. His vital signs at the time of the visit show BP: 130/70 mmHg, Pulse: 80, RR: 12, and T: 37.2 C. He has no current complaints and is eager for his surgery. Which of the following is the most appropriate course of action for this patient at this time?

Medically clear the patient for surgery

Tell the patient he will have to delay his surgery for at least 1 year

Repeat the patient's CBC and coagulation studies

Schedule the patient for a stress test and ask him to delay surgery for at least 6 months

A student health coordinator plans on leading a campus-wide HIV screening program that will be free for the entire undergraduate student body. The goal is to capture as many correct HIV diagnoses as possible with the fewest false positives. The coordinator consults with the hospital to see which tests are available to use for this program. Test A has a sensitivity of 0.92 and a specificity of 0.99. Test B has a sensitivity of 0.95 and a specificity of 0.96. Test C has a sensitivity of 0.98 and a specificity of 0.93. Which of the following testing schemes should the coordinator pursue?

Test C on the entire student body followed by Test A on those who are positive

Test A on the entire student body followed by Test B on those who are positive

Test A on the entire student body followed by Test C on those who are positive

Test C on the entire student body followed by Test B on those who are positive

Test B on the entire student body followed by Test A on those who are positive

A 17-year-old woman presents to the emergency department with dysuria. She denies any hematuria or dyspareunia. Her last menstrual period was 3 weeks ago, and she denies any recent sexual activity. Her temperature is 99.7°F (37.6°C), blood pressure is 127/67 mmHg, pulse is 90/min, and respirations are 17/min. An unusual odor is detected on inspection of the vagina and some gray discharge is noted. Speculum exam reveals a normal cervix and a bimanual exam is unremarkable for adnexal masses or tenderness. What is the next best step in management?

Urinalysis, urine culture, KOH prep, and urine pregnancy test

Urinalysis, KOH prep, and nucleic acid amplification tests for N. gonorrhea and C. trachomatis

Urinalysis, urine culture, and potassium hydroxide prep (KOH)

A 69-year-old man is scheduled to undergo radical retropubic prostatectomy for prostate cancer in 2 weeks. He had a myocardial infarction at the age of 54 years. He has a history of GERD, unstable angina, hyperlipidemia, and severe osteoarthritis in the left hip. He is unable to climb up stairs or walk fast because of pain in his left hip. He had smoked one pack of cigarettes daily for 30 years but quit 25 years ago. He drinks one glass of wine daily. Current medications include aspirin, metoprolol, lisinopril, rosuvastatin, omeprazole, and ibuprofen as needed. His temperature is 36.4°C (97.5°F), pulse is 90/min, and blood pressure is 136/88 mm Hg. Physical examination shows no abnormalities. A 12-lead ECG shows Q waves and inverted T waves in leads II, III, and aVF. His B-type natriuretic protein is 84 pg/mL (N < 125). Which of the following is the most appropriate next step in management to assess this patient's perioperative cardiac risk?

Radionuclide myocardial perfusion imaging

24-hour ambulatory ECG monitoring

A 66-year-old man with severe aortic stenosis (valve area 0.7 cm², mean gradient 55 mmHg) and Class III heart failure requires emergent hemicolectomy for perforated diverticulitis with peritonitis. He is hemodynamically stable on pressors. Cardiology states he is high-risk for valve replacement but could undergo TAVR in 2-3 weeks. The surgeon believes he needs surgery within 6-8 hours. Evaluate the management approach.

Proceed with colectomy under invasive monitoring with cardiology backup

Delay surgery, perform urgent TAVR, then colectomy in 2-3 weeks

Perform colostomy only under local anesthesia, defer resection

Medical management of perforation with antibiotics pending TAVR

Simultaneous TAVR and emergency colectomy in hybrid OR

A 35-year-old woman scheduled for thyroidectomy for papillary thyroid cancer is found to have prolonged aPTT (52 seconds, normal 25-35) on routine preoperative labs. PT/INR is normal. She has history of two first-trimester miscarriages but denies personal bleeding history. Further testing reveals lupus anticoagulant positivity. Evaluate the perioperative hemostatic management.

Proceed with surgery without additional precautions as bleeding risk is not increased

Cancel surgery and treat with anticoagulation indefinitely

Administer fresh frozen plasma preoperatively to correct aPTT

Start therapeutic anticoagulation and bridge perioperatively

Delay surgery, perform comprehensive thrombophilia workup, individualize management

A 48-year-old woman with newly diagnosed pheochromocytoma (4 cm right adrenal mass) is scheduled for laparoscopic adrenalectomy. Initial blood pressure is 180/110 mmHg with episodes of hypertension to 220/120 mmHg, headaches, and palpitations. Plasma metanephrines are markedly elevated. Evaluate the optimal preoperative preparation timeline and management.

Alpha-blockade for 7-14 days, then beta-blockade, volume expansion, then surgery

Urgent surgery within 48 hours with IV phentolamine available

Beta-blockade first to control heart rate, then surgery in one week

Combined alpha-beta blocker (labetalol) for one week, then surgery

Calcium channel blocker for blood pressure control and immediate surgery

Preoperative laboratory testing for USMLE Step 2 CK: High-Yield Surgery Lessons

Core Principles - Less is More

Paradigm Shift: Move away from routine, "shotgun" testing towards a selective, evidence-based approach.
Guiding Factors: Base decisions on a thorough history and physical (H&P), patient comorbidities, and the procedural risk (e.g., low, intermediate, high).
Primary Goal: Only order tests if the results will directly influence perioperative management (e.g., delay/cancel surgery, change anesthetic technique, or require new interventions).
Avoid testing in asymptomatic patients undergoing low-risk surgery, as it rarely provides clinical benefit.

⭐ In an asymptomatic patient, an abnormal preoperative lab result is more likely to be a false positive than a true indicator of disease.

Test Indications - The 'Who & Why'

Routine testing for healthy patients undergoing low-risk surgery is not indicated. Tests are ordered based on patient comorbidities, medication use, and the procedural risk.

Test	High-Yield Indications
CBC (Hemoglobin/Hematocrit, Platelets)	* Anticipated major blood loss (>500 mL) * Signs/symptoms of anemia or bleeding disorder * Chronic conditions: renal disease, cancer
BMP (Electrolytes, Creatinine, Glucose)	* Age >65 years * Known renal or adrenal disease * Medications: Diuretics, ACE-I/ARBs, Digoxin * Diabetes Mellitus
PT/PTT/INR	* Anticoagulant use (e.g., Warfarin, Heparin) * Known liver disease (cirrhosis) * Personal or family history of bleeding diathesis
LFTs (AST, ALT, Alk Phos, Bilirubin)	* Known acute or chronic liver disease * High-risk history: significant alcohol use, viral hepatitis exposure
β-hCG	* All females of childbearing potential ⚠️ Always perform, even if patient reports contraception or last menstrual period.

Clinical Pathway - A Testing Algorithm

⭐ Routine preoperative testing in healthy, asymptomatic patients undergoing low-risk surgery is not recommended as it rarely changes management and can lead to unnecessary workup.

Guiding Principle: Test only when results will influence perioperative management.
Low-Risk Surgery Examples: Endoscopy, cataract, superficial procedures.
High-Risk Surgery Examples: Major vascular, intraperitoneal, intrathoracic surgeries.
Specific Indications:
- CBC: For surgeries with high expected blood loss (EBL) or in patients with a history/symptoms of anemia.
- BMP/Electrolytes: For patients on diuretics, ACE-I/ARBs, or with known renal disease.
- ECG: Baseline for men > 45y, women > 55y, or with known cardiac disease, HTN, or DM.

High-Yield Points - ⚡ Biggest Takeaways

Avoid routine preoperative labs in healthy, asymptomatic patients.

Testing is guided by patient history, comorbidities, and surgical risk.

CBC for major surgery with high blood loss or known anemia.

PT/PTT/INR for patients on anticoagulants or with liver disease.

BMP for patients with CKD, on diuretics, or with diabetes.

ECG for patients with cardiac risk factors undergoing moderate-to-high risk surgery.

Urine hCG is essential for all women of childbearing potential.

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