USMLE Step 3 Quiz: Postoperative And Post Trauma Care

What this quiz covers

This quiz focuses on Postoperative And Post Trauma Care, giving you a quick way to practice the rules, question types, and explanations that matter most for USMLE Step 3.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Ascending cholangitis.
2. TPN-induced cholestasis.
3. Acute pancreatitis.
4. Acute acalculous cholecystitis. (correct answer)

Explanation: When you encounter a critically ill patient with gallbladder symptoms but no stones on imaging, think acute acalculous cholecystitis (AAC). This condition typically affects patients with severe illness, prolonged fasting, or TPN use—exactly what we see here. This patient's presentation perfectly fits AAC: he's critically ill with severe burns, has been on prolonged TPN (12 days), and shows the classic triad of fever, right upper quadrant pain, and leukocytosis. The ultrasound findings of gallbladder wall thickening >4mm, distension, and pericholecystic fluid without stones clinch the diagnosis. AAC occurs because critical illness and prolonged fasting lead to gallbladder stasis and ischemia, causing inflammation without obstruction. Looking at the wrong answers: (A) Ascending cholangitis would present with Charcot's triad (fever, jaundice, RUQ pain) and typically requires biliary obstruction—you'd expect dilated bile ducts on imaging. (B) TPN-induced cholestasis causes jaundice and elevated bilirubin rather than acute inflammatory symptoms with normal bile ducts. (C) Acute pancreatitis would cause epigastric pain radiating to the back with elevated lipase/amylase, not the focused RUQ tenderness and gallbladder changes seen here. For USMLE Step 3, remember that AAC is a high-yield diagnosis in ICU patients. Key associations include major surgery, burns, sepsis, prolonged fasting, and TPN use. Unlike calculous cholecystitis, stones are absent, but the inflammatory findings on imaging are the same. Early recognition is crucial since AAC can rapidly progress to perforation.

Question 2

1. Internal hernia with small bowel obstruction. (correct answer)
2. Marginal ulcer at the gastrojejunostomy.
3. Gastric dumping syndrome.
4. Acute calculous cholecystitis.

Explanation: When you encounter post-bariatric surgery patients with acute abdominal pain, think systematically about the unique complications these procedures create. Roux-en-Y gastric bypass creates several potential spaces where bowel can become trapped, making internal hernias a significant long-term risk. This patient's presentation strongly suggests internal hernia with small bowel obstruction. The severe, cramping periumbilical pain with non-bilious vomiting is classic for small bowel obstruction. The tachycardia indicates physiologic stress, while the absence of peritoneal signs suggests obstruction without perforation. Crucially, plain abdominal x-rays are often normal in early small bowel obstruction, especially when caused by internal hernias where bowel loops can appear deceptively normal on plain films. Option B, marginal ulcer at the gastrojejunostomy, typically presents with epigastric pain, often related to eating, and may cause hematemesis or melena rather than this obstruction pattern. Option C, gastric dumping syndrome, occurs shortly after eating and involves cramping with diarrhea, sweating, and palpitations - not the sustained severe pain described here. Option D, acute calculous cholecystitis, would cause right upper quadrant pain with possible Murphy's sign, not periumbilical cramping. For Step 3, remember that internal hernias are the most common cause of bowel obstruction in post-Roux-en-Y patients, often presenting months to years after surgery. When plain films are unremarkable but clinical suspicion is high, CT scan is the next step. Don't be fooled by normal plain films in suspected small bowel obstruction.

Question 3

1. Increase the demand dose on the PCA pump.
2. Obtain an urgent X-ray of the tibia and fibula.
3. Administer an intravenous bolus of ketorolac.
4. Immediately notify the orthopedic surgeon for possible fasciotomy. (correct answer)

Explanation: When you encounter progressive, severe post-operative pain in an extremity that's unresponsive to opioids, think compartment syndrome—a surgical emergency requiring immediate recognition and intervention. This patient presents classic signs of compartment syndrome: progressively worsening pain despite adequate analgesia, tense and tender lower leg, numbness in the first web space (deep peroneal nerve distribution), and severe pain with passive toe dorsiflexion. The mechanism involves increased pressure within fascial compartments that compromises circulation and nerve function. Tibial fractures, especially with intramedullary nailing, carry significant compartment syndrome risk due to bleeding and swelling in tight fascial spaces. Option D is correct because compartment syndrome requires emergency fasciotomy to relieve pressure and prevent permanent damage to muscles, nerves, and potentially limb loss. Every hour of delay increases morbidity. Option A is wrong because increasing morphine won't address the underlying pathophysiology and may mask important clinical signs. Pain from compartment syndrome is characteristically severe and opioid-resistant. Option B wastes critical time. While hardware complications exist, the clinical picture clearly suggests compartment syndrome, not implant failure. Option C is incorrect because ketorolac, though helpful for post-operative pain, cannot relieve compartment syndrome. NSAIDs may also increase bleeding risk in this setting. Study tip: Remember the "5 P's" of compartment syndrome: Pain (especially with passive stretch), Pressure, Pallor, Paresthesias, and Pulselessness. However, don't wait for all signs—severe pain with passive stretch is the earliest and most reliable indicator requiring immediate surgical consultation.

Question 4

1. Administer a single oral dose of tamsulosin.
2. Encourage ambulation and increased oral fluid intake.
3. Insert an indwelling Foley catheter to be left in for 3 days.
4. Perform a one-time, in-and-out bladder catheterization. (correct answer)

Explanation: When you encounter postoperative urinary retention, especially after spinal anesthesia in elderly men with BPH, you're dealing with a common but urgent complication that requires immediate relief to prevent bladder injury and patient discomfort. This patient has classic acute urinary retention with 700 mL in his bladder (normal capacity is 300-500 mL) and inability to void despite strong urge. The combination of spinal anesthesia (which temporarily impairs bladder function), his age, BPH history, and recent surgery creates the perfect storm for retention. Option D is correct because immediate bladder decompression is essential. A one-time, in-and-out catheterization provides instant relief without the infection risks of an indwelling catheter. Many patients regain normal voiding function once the spinal anesthesia completely wears off. Option A (tamsulosin) won't work fast enough - alpha-blockers take days to weeks for full effect, and this patient needs immediate relief. Option B (ambulation and fluids) is counterproductive - adding more fluid to an already overdistended bladder worsens the situation, and walking won't overcome the mechanical/neurological obstruction. Option C (indwelling Foley for 3 days) is unnecessarily invasive for what might be temporary retention; it significantly increases infection risk and isn't the first-line approach. For Step 3, remember that urinary retention with volumes >500-600 mL requires immediate catheterization. Always try the least invasive effective intervention first - straight catheterization before indwelling catheters unless multiple attempts are expected.

Question 5

1. Obtain blood cultures and start empiric broad-spectrum antibiotics.
2. Perform a CT scan of the abdomen and pelvis with oral and IV contrast. (correct answer)
3. Administer aggressive incentive spirometry and chest physiotherapy.
4. Request an urgent surgical consultation for exploratory laparotomy.

Explanation: The patient's presentation on postoperative day 5 with fever, tachycardia, localized abdominal pain, and leukocytosis is highly concerning for an intra-abdominal abscess or an anastomotic leak. A CT scan of the abdomen and pelvis with contrast is the most appropriate next step to confirm the diagnosis and guide further management, such as percutaneous drainage or surgical intervention. While antibiotics are necessary, they should be initiated after or concurrently with imaging to identify the source. Incentive spirometry targets atelectasis, which typically presents earlier (POD 1-2). Exploratory laparotomy is premature without first confirming the diagnosis with imaging.

Question 6

1. Diffusely dilated loops of both small and large bowel on abdominal x-ray.
2. A clear transition point with dilated proximal bowel and decompressed distal bowel on CT scan. (correct answer)
3. A serum potassium level of 3.2 mEq/L on laboratory testing.
4. Passage of a small amount of watery stool after a suppository.

Explanation: Differentiating prolonged postoperative ileus from an early mechanical small bowel obstruction is critical. While both can present with nausea, vomiting, and distention, the key feature of a mechanical obstruction is a discrete point of blockage. A CT scan showing a transition point with proximal dilation and distal collapse is the hallmark of mechanical obstruction. In contrast, ileus is characterized by generalized hypomotility of the entire gastrointestinal tract, which appears as diffusely dilated loops of both small and large bowel on imaging. Hypokalemia can cause or worsen an ileus but is not specific for obstruction.

Question 7

1. Synchronized electrical cardioversion.
2. An intravenous bolus of amiodarone.
3. An intravenous bolus of metoprolol. (correct answer)
4. An oral loading dose of digoxin.

Explanation: The patient has new-onset postoperative atrial fibrillation with a rapid ventricular response but is hemodynamically stable. The primary goal is rate control. Intravenous beta-blockers (e.g., metoprolol) or non-dihydropyridine calcium channel blockers (e.g., diltiazem) are the first-line agents for acute rate control in this setting. Synchronized cardioversion is reserved for hemodynamically unstable patients. Amiodarone is typically a second-line agent for rate control or can be used for rhythm control. Digoxin has a slow onset of action and is not ideal for acute management.

Question 8

1. Reassure her that this is a normal stress response that will resolve with time.
2. Prescribe a short-term course of alprazolam to use as needed for anxiety.
3. Recommend she begin a graded exposure program by sitting in a parked car daily.
4. Refer her to a mental health professional for trauma-focused psychotherapy. (correct answer)

Explanation: When you encounter a patient presenting with trauma-related symptoms following a significant event, you need to systematically assess the duration, severity, and functional impact to distinguish between normal stress responses and clinical disorders like PTSD. This patient presents with classic PTSD symptoms occurring 6 weeks post-trauma: intrusive memories (re-experiencing), nightmares, avoidance behaviors (won't get in cars), emotional numbing (detachment from others), and hypervigilance ("on edge"). Crucially, these symptoms are causing significant functional impairment (can't return to work) and have persisted beyond the typical acute stress response timeframe. PTSD requires specialized trauma-focused psychotherapy as first-line treatment, making referral to a mental health professional (D) the most appropriate intervention. Option A is incorrect because while some initial stress response is normal, symptoms persisting 6 weeks with functional impairment indicate a clinical disorder requiring active treatment. Option B represents poor practice - benzodiazepines like alprazolam can actually worsen PTSD outcomes by interfering with natural fear extinction and increasing dependency risk. Option C is premature and potentially harmful; graded exposure should only be conducted by trained professionals as part of structured therapy, not as self-directed treatment. For USMLE Step 3, remember that PTSD diagnosis requires symptoms lasting more than one month with functional impairment. Always choose evidence-based treatments: trauma-focused psychotherapy (like CPT or EMDR) is first-line, not medications or reassurance. Watch for questions that tempt you toward benzodiazepines for trauma - they're typically contraindicated.

Question 9

1. A long-acting opioid, such as oxycodone ER.
2. An oral corticosteroid taper over two weeks.
3. A tricyclic antidepressant, such as amitriptyline. (correct answer)
4. A muscle relaxant, such as cyclobenzaprine.

Explanation: This patient's constellation of symptoms—severe burning pain (hyperalgesia), pain from a non-painful stimulus (allodynia), and autonomic dysfunction (changes in skin color, temperature, swelling)—following trauma is classic for Complex Regional Pain Syndrome (CRPS). Management is multimodal, including physical therapy. First-line pharmacologic treatments are aimed at neuropathic pain and include tricyclic antidepressants (e.g., amitriptyline, nortriptyline), gabapentinoids (gabapentin, pregabalin), and topical agents. Opioids are not first-line and are generally avoided for chronic neuropathic pain.

Question 10

1. Begin an infusion of norepinephrine.
2. Administer intravenous hydrocortisone. (correct answer)
3. Obtain an urgent abdominal CT to rule out a bile leak.
4. Administer broad-spectrum antibiotics for sepsis.

Explanation: This patient's chronic use of high-dose corticosteroids has likely caused suppression of the hypothalamic-pituitary-adrenal (HPA) axis. The stress of surgery can precipitate an acute adrenal crisis in such patients if they do not receive perioperative stress-dose steroids. The presentation of refractory hypotension, fever, hyponatremia, and hyperkalemia is classic for adrenal crisis. The most critical and life-saving intervention is the immediate administration of intravenous hydrocortisone. While vasopressors and antibiotics may also be needed, treating the underlying adrenal insufficiency is paramount.

Question 11

1. Obtain a CT pulmonary angiography (CTPA). (correct answer)
2. Obtain a ventilation-perfusion (V/Q) scan.
3. Measure a serum D-dimer level.
4. Perform a transthoracic echocardiogram.

Explanation: When you encounter a patient with acute onset pleuritic chest pain and dyspnea following major surgery, pulmonary embolism (PE) should be your primary concern. This 62-year-old woman has classic risk factors: recent orthopedic surgery, immobilization, and advanced age. Despite prophylactic anticoagulation, breakthrough PE can still occur, especially after high-risk procedures like knee arthroplasty. The correct answer is A because CT pulmonary angiography (CTPA) is the gold standard diagnostic test for PE in hemodynamically stable patients. It provides rapid, accurate visualization of pulmonary vessels and can detect emboli directly. Given her clear clinical presentation and intermediate-to-high pretest probability, immediate imaging is warranted. Option B, V/Q scanning, is primarily used when CTPA is contraindicated (renal insufficiency, contrast allergy) or unavailable. It's less specific and takes longer to complete. Option C, D-dimer measurement, would likely be elevated but lacks specificity in postoperative patients due to ongoing inflammation and healing processes. A negative D-dimer might be useful to rule out PE in low-risk patients, but this patient's high pretest probability makes it unhelpful. Option D, echocardiography, might show right heart strain in severe PE but cannot diagnose PE directly and wouldn't be the initial diagnostic test. Remember: In postoperative patients with suspected PE and intermediate-to-high pretest probability, proceed directly to CTPA rather than using screening tests like D-dimer. Time is critical, and definitive imaging provides both diagnosis and guides immediate treatment decisions.

Question 12

1. Continue IV fluids alone until bowel sounds return.
2. Initiate total parenteral nutrition (TPN) via his central line.
3. Place a nasojejunal feeding tube and begin trophic enteral feeds. (correct answer)
4. Initiate full-strength gastric feeds via his nasogastric tube.

Explanation: Early enteral nutrition (within 24-48 hours) is strongly recommended in critically ill patients to maintain gut mucosal integrity, reduce septic complications, and modulate the stress response. Waiting for bowel sounds to return is an outdated practice. TPN is associated with more complications (e.g., infection, cholestasis) and should be avoided if the gut is usable. Since the patient likely has a gastric ileus, post-pyloric feeding via a nasojejunal (or dobhoff) tube is the preferred method to deliver enteral nutrition. Starting with trophic ('trickle') feeds is a common strategy to assess tolerance.

Question 13

1. He can be scheduled for ileostomy reversal in 2 to 4 weeks.
2. He will require lifelong total parenteral nutrition.
3. A contrast enema or flexible sigmoidoscopy should be performed prior to ileostomy reversal. (correct answer)
4. The anastomosis should be resected and a permanent end colostomy created.

Explanation: Before reversing a diverting ileostomy, especially after an anastomotic leak, it is mandatory to confirm the integrity and healing of the downstream anastomosis. This is typically done with a contrast study (e.g., water-soluble contrast enema) or endoscopy to ensure there is no persistent leak, stricture, or other pathology. Proceeding with reversal without this confirmation would be unsafe. Scheduling reversal is premature. Lifelong TPN is not indicated. A permanent colostomy is not necessary if the leak has healed and the anastomosis is intact.

Question 14

1. Administer a low dose of intravenous haloperidol. (correct answer)
2. Apply soft wrist restraints to both arms.
3. Administer a low dose of intravenous lorazepam.
4. Request a neurology consultation for an emergent head CT.

Explanation: This patient is experiencing postoperative delirium, a common complication in elderly surgical patients. After ruling out and correcting underlying medical causes (hypoxia, electrolyte imbalance, infection, etc.), management focuses on non-pharmacologic strategies. When these fail and the patient's agitation poses a safety risk, a low-dose antipsychotic agent like haloperidol is the preferred pharmacologic treatment. Benzodiazepines (e.g., lorazepam) should be avoided as they can worsen delirium in the elderly (unless treating alcohol withdrawal). Restraints are a last resort and can exacerbate agitation.

Question 15

1. Administer systemic thrombolysis if no absolute contraindications are present (correct answer)
2. Schedule outpatient V/Q scan because CT contrast may worsen kidney function
3. Give nebulized bronchodilators for presumed postoperative bronchospasm
4. Start oral anticoagulation only and avoid parenteral therapy initially

Explanation: This question tests USMLE Step 3 competencies in postoperative and post-trauma care, focusing on management strategies and complication prevention. Understanding the principles of postoperative care involves recognizing common complications and appropriate interventions based on clinical guidelines. In this scenario, the patient presents with sudden dyspnea, syncope, hypotension, tachycardia, and RV dilation on echo two days after knee surgery, necessitating consideration of massive pulmonary embolism management. Choice A is correct because it directly addresses the patient's current clinical needs, aligning with best practices for thrombolysis in hemodynamically unstable PE. Choice B is incorrect because it reflects a common misconception, such as delaying for outpatient imaging, leading to inadequate management and mortality risk. To enhance learning, students should focus on mastering complication recognition and prioritization of care, utilizing scenario-based practice to reinforce decision-making skills and prevent common clinical pitfalls.

Question 16

1. Apply an abdominal binder tightly and instruct the patient to remain on strict bed rest.
2. Obtain an urgent CT scan of the abdomen and pelvis to assess the extent of fascial separation.
3. Cover the wound with sterile gauze soaked in saline and prepare for urgent surgical repair. (correct answer)
4. Administer a dose of IV antibiotics and obtain fluid for culture from the wound.

Explanation: This patient's presentation is classic for abdominal fascial dehiscence, a surgical emergency where the fascial closure fails, potentially leading to evisceration (protrusion of abdominal contents). The immediate action is to cover the wound with sterile, saline-soaked dressings to protect the underlying viscera from desiccation and contamination. The patient should be made NPO and prepared for an urgent return to the operating room for fascial re-closure. Imaging would delay definitive treatment, and an abdominal binder is insufficient. Antibiotics are important but not the most immediate life-saving step.

Question 17

1. Prescribe a 10-day course of oral cephalexin and apply warm compresses.
2. Open the incision over the fluctuant area, obtain a culture, and pack the wound open. (correct answer)
3. Obtain an ultrasound of the incision and wait for results before intervening.
4. Admit the patient to the hospital for intravenous vancomycin.

Explanation: The patient has a superficial surgical site infection with abscess formation, indicated by the area of fluctuance. The cornerstone of management for an abscess is incision and drainage. Antibiotics alone are insufficient. In an outpatient setting, this can be done by removing a few sutures/staples, gently probing to drain the purulent collection, obtaining a culture, and lightly packing the wound to allow it to drain and heal by secondary intention. Imaging is not necessary for a clinically obvious superficial abscess. Hospital admission and IV antibiotics are reserved for patients with systemic signs of infection (high fever, tachycardia, hypotension) or deep/complex infections.

Question 18

1. Reassure the patient that bladder spasms are common after catheter removal.
2. Obtain a urinalysis and urine culture, and start empiric antibiotics. (correct answer)
3. Perform a renal ultrasound to evaluate for hydronephrosis.
4. Start empiric oral metronidazole for possible C. difficile infection.

Explanation: The combination of new urinary symptoms (dysuria, frequency) and fever in a patient who was recently catheterized is highly suggestive of a catheter-associated urinary tract infection (CAUTI). Even though the catheter has been removed, the infection may have been acquired during its placement. The most appropriate management is to obtain a urinalysis and urine culture to guide therapy and to start empiric antibiotics targeted at common uropathogens (e.g., E. coli). Reassurance is inappropriate given the fever. Renal ultrasound is not indicated for an uncomplicated UTI. The symptoms are not consistent with C. difficile colitis.

Question 19

1. Administer large-volume crystalloid bolus and reassess after 3 liters
2. Activate massive transfusion protocol and proceed to emergent operative control (correct answer)
3. Order CT abdomen/pelvis with contrast to localize bleeding source
4. Start therapeutic heparin for suspected pulmonary embolism causing shock

Explanation: This question tests USMLE Step 3 competencies in postoperative and post-trauma care, focusing on management strategies and complication prevention. Understanding the principles of postoperative care involves recognizing common complications and appropriate interventions based on clinical guidelines. In this scenario, the patient presents with hypotension, tachycardia, positive FAST, low hemoglobin, and elevated lactate after MVC, necessitating consideration of hemorrhagic shock management. Choice B is correct because it directly addresses the patient's current clinical needs, aligning with best practices for massive transfusion and operative control in unstable trauma. Choice A is incorrect because it reflects a common misconception, such as relying solely on crystalloids, leading to inadequate management and dilutional coagulopathy. To enhance learning, students should focus on mastering complication recognition and prioritization of care, utilizing scenario-based practice to reinforce decision-making skills and prevent common clinical pitfalls.

Question 20

1. Arrange for urgent cardiac catheterization and possible percutaneous coronary intervention.
2. Initiate a therapeutic-dose intravenous heparin infusion. (correct answer)
3. Administer intravenous thrombolytic therapy with alteplase.
4. Administer a 1-liter bolus of normal saline to improve preload.

Explanation: This patient has a perioperative non-ST-elevation myocardial infarction (NSTEMI), characterized by atypical symptoms, new ECG changes, and an elevated troponin level. The management must balance the risk of coronary thrombosis against the high risk of bleeding from the recent partial nephrectomy. Thrombolytics are absolutely contraindicated. Urgent cardiac catheterization is associated with a very high bleeding risk and is typically deferred unless there is hemodynamic instability or refractory ischemia. The standard of care involves medical management, including antiplatelet therapy (aspirin) and anticoagulation (e.g., a heparin infusion), along with beta-blockers and statins, while carefully monitoring for bleeding.