USMLE Step 2 CK Surgical Emergencies: Torsion, Mesenteric Ischemia, Pancreatitis and Variceal Bleeding

Step 2 CK loves “next best step” questions about emergencies. The key is to spot the case that cannot wait: torsion goes straight to surgery, mesenteric ischemia needs CT angiography, and an unstable patient needs resuscitation first. Read the table, then try these 10 clinical cases.

Surgical emergencies at a glance

Emergency Key clue Next step
Testicular torsion Sudden pain, high-riding testis, absent cremasteric reflex Surgery now (do not wait for ultrasound)
Ovarian torsion Sudden one-sided pelvic pain, enlarged ovary, low blood flow Emergency laparoscopy
Acute mesenteric ischemia Pain out of proportion to exam, atrial fibrillation, high lactate CT angiography
Ischemic colitis Pain then bloody stool after aortic surgery or low blood flow Supportive care; CT and colonoscopy
Severe acute pancreatitis Shock or low oxygen despite fluids ICU care
Variceal bleeding Alcohol use, vomiting blood, shock Fluids, IV octreotide, antibiotics, then banding
Malignant hyperthermia Rigidity, fever, high CO2 after anesthesia Stop the trigger, give dantrolene

Question 1: Sudden scrotal pain

A 29-year-old man has sudden, severe scrotal pain and nausea. The testis is high-riding with a horizontal lie, and the cremasteric reflex is absent. What is the best next step?

A. Oral antibiotics
B. Scrotal ultrasound before any intervention
C. Supportive care and discharge
D. Immediate surgical exploration

Correct answer: D. Immediate surgical exploration

This is testicular torsion, a surgical emergency. When the clinical picture is clear, do not delay surgery for imaging. The testis is most likely to be saved if it is untwisted within 6 hours. Both testes are fixed (orchiopexy) during the operation.

Torsion vs epididymitis: torsion starts suddenly, the testis rides high, the cremasteric reflex is absent and lifting the scrotum does not help (negative Prehn sign). Epididymitis comes on gradually, often with fever or dysuria, the reflex is present, and lifting the scrotum may ease the pain.

Why the other options are wrong:

  • Antibiotics treat epididymitis, not torsion.
  • Ultrasound wastes time when the diagnosis is clear; it is used only when the diagnosis is uncertain.
  • Discharge would lead to loss of the testis.

Question 2: One-sided pelvic pain with an enlarged ovary

A 24-year-old woman has sudden, severe one-sided lower abdominal pain and nausea. Ultrasound shows an enlarged ovary with decreased blood flow. What is the best next step?

A. Broad-spectrum antibiotics
B. Emergency laparoscopy
C. Repeat ultrasound in 24 hours
D. Start oral contraceptives

Correct answer: B. Emergency laparoscopy

This is ovarian torsion. An ovarian cyst or mass (often over 5 cm) makes the ovary twist on its blood supply. Like testicular torsion, it is a surgical emergency: laparoscopy to untwist the ovary and save it. Doppler blood flow can look normal in some cases, so a strong clinical picture still needs surgery.

Why the other options are wrong:

  • Antibiotics are for pelvic inflammatory disease or abscess.
  • Waiting 24 hours risks losing the ovary.
  • Oral contraceptives may prevent new cysts but do not treat torsion.

Question 3: PID that gets worse

A 31-year-old woman has pelvic pain and fever for 2 days. She has purulent cervical discharge and cervical motion tenderness. Her pregnancy test is negative. She is diagnosed with pelvic inflammatory disease (PID) and started on antibiotics. Two days later, she returns with worse pain and a tender adnexal mass. What is the most likely diagnosis?

A. Appendicitis
B. Ectopic pregnancy
C. Ovarian torsion
D. Tubo-ovarian abscess

Correct answer: D. Tubo-ovarian abscess

PID that does not improve on antibiotics and now has an adnexal mass suggests a tubo-ovarian abscess. It is confirmed by ultrasound or CT. Treatment is hospital admission with IV antibiotics, and drainage if the abscess is large (about 7 cm or more) or does not respond. A ruptured abscess is a surgical emergency.

Why the other options are wrong:

  • Appendicitis does not cause cervical discharge and cervical motion tenderness.
  • Ectopic pregnancy is ruled out by the negative pregnancy test.
  • Ovarian torsion starts suddenly and is not usually caused by PID.

Question 4: Pain out of proportion to the exam

A 72-year-old woman with atrial fibrillation has sudden, severe abdominal pain. Her abdomen is soft with little tenderness. Lactate is high. What is the best next diagnostic step?

A. Abdominal ultrasound
B. Colonoscopy
C. CT angiography
D. Plain abdominal X-ray

Correct answer: C. CT angiography

Pain out of proportion to the physical exam in a patient with atrial fibrillation is acute mesenteric ischemia until proven otherwise, most often from an embolus to the superior mesenteric artery. CT angiography is the test of choice. Treatment is fluids, heparin, and urgent restoration of blood flow (embolectomy or endovascular therapy), with removal of any dead bowel.

Why the other options are wrong:

  • Ultrasound and plain X-ray are not reliable for this diagnosis; X-ray findings appear late.
  • Colonoscopy does not show the small bowel or the mesenteric arteries and is risky in ischemic bowel.

Question 5: Bloody stool after aneurysm repair

A 76-year-old woman has abdominal pain followed by bright red blood per rectum. She recently had repair of an abdominal aortic aneurysm. What is the most likely diagnosis?

A. Diverticular bleeding
B. Infectious colitis
C. Ischemic colitis
D. Ulcerative colitis

Correct answer: C. Ischemic colitis

Ischemic colitis happens when blood flow to the colon drops. AAA repair can tie off the inferior mesenteric artery. The watershed areas are most at risk: the splenic flexure and the rectosigmoid junction. The typical story is crampy pain followed by bloody diarrhea. Most cases improve with fluids, bowel rest and observation.

Why the other options are wrong:

  • Diverticular bleeding is usually painless.
  • Infectious colitis does not fit the timing after vascular surgery.
  • Ulcerative colitis is a chronic disease that usually starts in young adults.

Question 6: Gallstone pancreatitis that is settling down

A 61-year-old man has sudden, severe abdominal pain after a large meal. The pain goes through to his back. Lipase is very high. Ultrasound shows gallstones without a dilated bile duct. He improves with fluids and pain control. What is the most appropriate next step?

A. Cholecystectomy during the same hospital stay
B. ERCP
C. Immediate laparotomy
D. Start antibiotics

Correct answer: A. Cholecystectomy during the same hospital stay

In mild gallstone pancreatitis without cholangitis or a blocked bile duct, the patient gets supportive care and then cholecystectomy during the same admission. If surgery is delayed, many patients have another attack within weeks.

Why the other options are wrong:

  • ERCP is for cholangitis or a persistently blocked common bile duct.
  • Laparotomy is not needed in uncomplicated pancreatitis.
  • Antibiotics are not routine in pancreatitis; they are used for infected necrosis or cholangitis.

Question 7: Pancreatitis with shock and low oxygen

A 64-year-old man has severe epigastric pain going through to his back. He has fever and a fast heart rate. Lipase is 1,800 U/L and ultrasound shows gallstones. Despite IV fluids and pain control, over the next 12 hours he becomes hypotensive and his oxygen level falls. What is the best next step?

A. Broad-spectrum antibiotics now
B. ERCP now
C. Start oral feeding
D. Transfer to the ICU for aggressive supportive care

Correct answer: D. Transfer to the ICU for aggressive supportive care

This is severe acute pancreatitis with organ failure (shock and respiratory failure, which can be ARDS). He needs ICU care: fluids, oxygen or ventilation, and close monitoring. Early feeding through the gut (when possible) is preferred later over IV nutrition.

Why the other options are wrong:

  • Antibiotics are not routine; give them only if infected necrosis or cholangitis is suspected.
  • ERCP is for cholangitis or a bile duct that stays blocked.
  • Oral feeding is not safe in an unstable patient with falling oxygen.

Question 8: Fever and free air after colon surgery

A 57-year-old man has a colon resection. On day 3 after surgery he develops fever, a fast heart rate and abdominal pain. His blood pressure is 88/50 mm Hg. The abdomen is distended and tender. CT shows free air and a fluid collection. What is the best next step?

A. Broad-spectrum antibiotics only
B. Percutaneous drainage
C. Return to the operating room
D. Supportive care and observation

Correct answer: C. Return to the operating room

This is an anastomotic leak with peritonitis and shock. A leak typically appears days 3 to 7 after bowel surgery. With diffuse peritonitis and an unstable patient, the answer is to return to the operating room (along with fluids and antibiotics).

Why the other options are wrong:

  • Antibiotics alone or observation are not enough in an unstable patient with peritonitis.
  • Percutaneous drainage is used only for a small, contained leak in a stable patient.

Question 9: Fever and rigidity after anesthesia

A 71-year-old man develops high fever, muscle rigidity, a fast heart rate and confusion while recovering from general anesthesia for hip surgery. Labs show very high creatine kinase, high potassium and acidosis. What is the most likely diagnosis?

A. Malignant hyperthermia
B. Neuroleptic malignant syndrome
C. Serotonin syndrome
D. Thyroid storm

Correct answer: A. Malignant hyperthermia

Malignant hyperthermia is an inherited reaction (often a RYR1 mutation, autosomal dominant) to volatile anesthetics or succinylcholine. Uncontrolled calcium release in muscle causes rigidity, high fever, rising end-tidal CO2, high CK, high potassium and acidosis. Treatment: stop the trigger, give IV dantrolene, cool the patient and treat the high potassium.

Why the other options are wrong:

  • Neuroleptic malignant syndrome follows antipsychotic drugs and develops over days.
  • Serotonin syndrome follows serotonergic drugs and causes clonus and hyperreflexia, not lead-pipe rigidity.
  • Thyroid storm does not cause rigidity or a very high CK.

Question 10: Vomiting blood with a history of alcohol use

A 60-year-old man with long-term alcohol use is vomiting large amounts of bright red blood. He is hypotensive and tachycardic. Bleeding esophageal varices are suspected. What is the best initial management?

A. Start a β-blocker
B. Endoscopic band ligation before any other treatment
C. IV fluids, blood as needed and IV octreotide
D. IV proton pump inhibitor alone

Correct answer: C. IV fluids, blood as needed and IV octreotide

The first step in any major GI bleed is to stabilize the patient: two large IV lines, fluids and blood. For suspected variceal bleeding, also give IV octreotide (lowers portal pressure) and IV antibiotics such as ceftriaxone (prevents infection and lowers death rates in cirrhosis). Endoscopic band ligation follows within 12 hours, once the patient is stable.

Why the other options are wrong:

  • β-blockers (propranolol, nadolol) are for preventing bleeding, not for active bleeding with low blood pressure.
  • Banding comes after resuscitation, not before.
  • A PPI alone is the treatment for a peptic ulcer, not for varices.

Key takeaways

  • Testicular torsion: go to surgery without waiting for ultrasound; best within 6 hours.
  • Ovarian torsion: emergency laparoscopy.
  • PID that gets worse on antibiotics with a mass: tubo-ovarian abscess.
  • Pain out of proportion plus atrial fibrillation: mesenteric ischemia, so order CT angiography.
  • Bloody diarrhea after AAA repair: ischemic colitis (splenic flexure, rectosigmoid).
  • Gallstone pancreatitis: cholecystectomy in the same admission. Severe pancreatitis with organ failure: ICU.
  • Fever and shock 3 to 7 days after bowel surgery: anastomotic leak, back to the operating room.
  • Malignant hyperthermia: dantrolene. Variceal bleeding: resuscitation, octreotide, antibiotics, then banding.

More USMLE practice questions

Repeated USMLE Questions Step 2 CK Review Vol 1 book cover

Want 100+ more clinical questions like these?

Get Repeated USMLE Questions Step 2 CK Review Vol 1 by Dr. Ray Makar

Buy on Amazon →

As an Amazon Associate, I earn from qualifying purchases.

Written and reviewed by Dr. Ray Makar, MD, dermatologist with 20 years of clinical practice. Last reviewed: November 2026. For exam preparation only, not medical advice.

FREE USMLE PDFs

Get 80 free practice questions

Four free sampler PDFs by Dr. Ray Makar: Step 1 (Pathology & Pharmacology) and Step 2 CK (Medicine, Surgery & Pediatrics), in both Review style and USMLE style, with answers and explanations. Also useful for NEET-PG, INI-CET and FMGE.

Download the free PDFs See the full books →

Leave a Comment