Surgery

1344 questions

Question 881Question →

A 52-year-old man is transported to the trauma center by helicopter after a high-speed head-on motor vehicle collision. On arrival, he is confused and diaphoretic. His blood pressure is 82/54 mm Hg, heart rate is 128/min, and respiratory rate is 22/min. Oxygen saturation is 97% on a nonrebreather mask. The airway is secure, and breath sounds are present and equal bilaterally. The abdomen is grossly distended and rigid to palpation. Pelvic compression does not elicit instability. Intravenous access is established, and rapid fluid resuscitation with warmed crystalloid is initiated. A focused assessment with sonography for trauma (FAST) examination reveals an anechoic stripe in the hepatorenal recess. Which of the following is the most appropriate next step in management?

Show answer & explanation

Answer: Exploratory laparotomy

Answer

Exploratory laparotomy
This patient presents with hypovolemic shock (hypotension, tachycardia, diaphoresis) following blunt abdominal trauma. The focused assessment with sonography for trauma (FAST) reveals an anechoic stripe in the hepatorenal recess (Morison's pouch), which confirms the presence of intraperitoneal fluid (blood). In the setting of hemodynamic instability and a positive FAST, the immediate standard of care is exploratory laparotomy to identify and control the source of intra-abdominal hemorrhage.

Step-by-Step Solution

1
Assess the patient's hemodynamic status.
The patient is hemodynamically unstable, evidenced by a blood pressure of 82/54 mm Hg, heart rate of 128/min, confusion, and diaphoresis.
Hemodynamic stability is the primary decision branch point in the ATLS algorithm for evaluating blunt abdominal trauma.
2
Evaluate the primary survey findings to localize the source of bleeding.
The patient has a grossly distended and rigid abdomen with a positive FAST exam indicating intraperitoneal fluid (blood).
A positive FAST exam confirms that the peritoneal cavity is the source of the hemorrhagic shock.
3
Determine the definitive next step in management.
The patient must undergo an immediate exploratory laparotomy.
A hemodynamically unstable patient with evidence of ongoing intra-abdominal hemorrhage requires prompt surgical exploration to achieve definitive hemostasis.

Key Concept

Hemodynamically unstable patients with blunt abdominal trauma and evidence of intraperitoneal hemorrhage on a FAST exam require immediate exploratory laparotomy.
Question 882Question →

A 29-year-old woman is evaluated in the post-anesthesia care unit (PACU) due to severe agitation and a rapidly rising temperature. She just underwent an emergency laparoscopic appendectomy for a perforated appendix. Her medical history is significant for major depressive disorder, for which she takes sertraline daily. Intraoperative medications included propofol, succinylcholine, desflurane, fentanyl, and ondansetron. Reversal of neuromuscular blockade was achieved with sugammadex. Her temperature is 39.6∘C39.6^\circ\text{C} (103.3∘F103.3^\circ\text{F}), blood pressure is 168/96 mmHg168/96\text{ mmHg}, pulse is 138/min138/\text{min}, and respiratory rate is 24/min24/\text{min}. On physical examination, she is diaphoretic, flushed, and disoriented. Neurologic examination reveals marked hyperreflexia in the bilateral lower extremities, spontaneous myoclonus, and inducible ocular clonus. Her muscle tone is increased, particularly in the lower extremities, but there is no "lead-pipe" rigidity. An arterial blood gas analysis shows a normal partial pressure of carbon dioxide (PaCO2PaCO_2). Administration of a medication with which of the following mechanisms of action is the most appropriate targeted therapy for this patient's current condition?

Show answer & explanation

Answer: Antagonism of 5−HT2A5-\text{HT}_{2A} receptors

Answer

Antagonism of 5-HT2A receptors (such as Cyproheptadine)
The correct answer describes the mechanism of action of cyproheptadine. This patient is suffering from classic Serotonin Syndrome (SS), precipitated by the combination of her home SSRI (sertraline) and serotonergic intraoperative medications (fentanyl and ondansetron). SS is characterized by the triad of autonomic hyperactivity (tachycardia, hyperthermia, diaphoresis), altered mental status, and neuromuscular irritability. The presence of hyperreflexia, spontaneous myoclonus, and inducible ocular clonus is highly specific for SS. The specific targeted antidote for moderate-to-severe SS is cyproheptadine, which exerts its primary therapeutic effect through the antagonism of 5−HT1A5-\text{HT}_{1A} and 5−HT2A5-\text{HT}_{2A} receptors.

Step-by-Step Solution

1
Analyze the patient's medication history.
The patient takes a home SSRI (sertraline) and received fentanyl and ondansetron intraoperatively. All three medications possess strong serotonergic activity.
Identifying potential drug interactions is critical in the immediate postoperative period.
2
Correlate medications with the physical examination findings.
The combination of autonomic hyperactivity (tachycardia, hyperthermia, diaphoresis), altered mental status, and profound neuromuscular irritability (hyperreflexia, myoclonus, ocular clonus) definitively establishes a diagnosis of Serotonin Syndrome.
Neuromuscular findings are key to distinguishing toxidromes.
3
Differentiate the presentation from Malignant Hyperthermia (MH).
Although the patient received succinylcholine and desflurane (classic MH triggers), MH presents with hyporeflexia, lead-pipe rigidity (often masseter spasm), and severe hypercapnia (elevated PaCO2). The patient's hyperreflexia, clonus, and normal PaCO2 rule out MH.
MH and Serotonin Syndrome are both life-threatening PACU emergencies that cause hyperthermia but require completely different antidotes.
4
Determine the targeted pharmacologic therapy.
For moderate-to-severe Serotonin Syndrome that does not respond to supportive care and benzodiazepines, the antidote of choice is cyproheptadine, which works primarily via antagonism of 5-HT2A receptors.
To reverse the specific neuroreceptor overstimulation causing the crisis.

Key Concept

Differentiating perioperative toxidromes (Serotonin Syndrome vs. Malignant Hyperthermia) and applying the correct mechanism-specific antidote.
Question 883Question →

Correlate the following classic clinical findings in blunt trauma patients with their most likely associated underlying injury.

Click a left item, then click its matching right item

Items

Referred left shoulder pain following blunt abdominal trauma
Hypotension, jugular venous distention, and muffled heart sounds
Transverse linear ecchymosis across the lower abdomen after a motor vehicle collision
Palpable subcutaneous emphysema and a systolic precordial crunching sound

Matches

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Answer

Referred left shoulder pain correlates with Splenic laceration. Hypotension, JVD, and muffled heart sounds correlate with Cardiac tamponade. Transverse lower abdominal ecchymosis correlates with Mesenteric or hollow viscus injury. Subcutaneous emphysema with a crunching sound correlates with Tracheobronchial tree disruption.
Each classic trauma sign accurately correlates with a distinct pathophysiological process. Identifying these signs allows for rapid diagnosis and prioritization during the ATLS primary survey. Splenic laceration causes diaphragmatic irritation; tamponade restricts cardiac filling; seatbelts cause mesenteric shearing; and airway disruption introduces air into the mediastinum.

Step-by-Step Solution

1
Evaluate the mechanism of referred left shoulder pain.
Identify that it is caused by left hemidiaphragmatic irritation (phrenic nerve, C3-C5), which is classically caused by a bleeding spleen.
The spleen is located in the left upper quadrant, and rupture directly irritates the left diaphragm.
2
Analyze the triad of hypotension, JVD, and muffled heart sounds.
Recognize this as Beck triad, the classic clinical presentation of cardiac tamponade.
Pericardial fluid restricts ventricular filling, leading to obstructive shock and elevated right-sided pressures.
3
Interpret the significance of a seatbelt mark on the abdomen.
Correlate this specific ecchymosis with high-energy deceleration, leading to crushing or shearing of intra-abdominal contents.
Hollow viscera and the mesentery are particularly vulnerable to these specific shearing forces.
4
Determine the source of a precordial crunch (Hamman sign) and subcutaneous air.
Identify pneumomediastinum, most commonly resulting from injury to a major airway structure.
Disruption of the tracheobronchial tree allows air to track upward into the mediastinum and soft tissues of the chest.

Key Concept

Recognition of classic physical examination findings in trauma and their anatomical correlations.
Estimated Time:45s
Question 884Question →

A 78-year-old woman is evaluated in the emergency department for a 3-day history of progressively worsening abdominal distension, nausea, and vomiting of brown, foul-smelling fluid. She has not had a bowel movement or passed flatus for 48 hours. Her medical history includes hypertension, diet-controlled type 2 diabetes mellitus, and multiple episodes of right upper quadrant pain after meals over the past year. Her temperature is 37.8°C (100.0°F), blood pressure is 105/65 mmHg, pulse is 112/min, and respirations are 20/min. Physical examination shows a significantly distended, tympanitic abdomen with high-pitched, tinkling bowel sounds. There is diffuse tenderness to palpation but no guarding or rebound tenderness.

Laboratory studies reveal:
TestResult
Leukocyte count11,500/mm³
Sodium132 mEq/L
Potassium3.1 mEq/L
Blood urea nitrogen42 mg/dL
Creatinine1.6 mg/dL

A non-contrast computed tomography scan of the abdomen demonstrates dilated small bowel loops up to the distal ileum, air in the biliary tree, and a 3.5-cm radiopaque structure in the right lower quadrant. Which of the following is the most appropriate next step in management?

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Answer: Exploratory laparotomy with enterolithotomy

Answer

Exploratory laparotomy with enterolithotomy
This patient's clinical presentation and imaging findings (pneumobilia, small bowel obstruction, and an ectopic radiopaque stone in the right lower quadrant) are classic for gallstone ileus (Rigler's triad). This condition occurs when a large gallstone erodes through the gallbladder wall into the adjacent duodenum, creating a cholecystoduodenal fistula. The stone travels through the small intestine and typically impacts at the narrowest point, the terminal ileum, causing a mechanical obstruction. The most appropriate management is emergent exploratory laparotomy with enterolithotomy (surgical extraction of the stone) to relieve the obstruction. A one-stage procedure including cholecystectomy and fistula repair is generally avoided in the acute setting due to a significantly higher mortality rate, especially in elderly patients with multiple comorbidities.

Step-by-Step Solution

1
Identify the diagnosis based on the clinical presentation and imaging findings.
The patient has gallstone ileus, characterized by a mechanical small bowel obstruction, pneumobilia, and an ectopic gallstone (Rigler's triad).
The CT scan shows dilated small bowel, air in the biliary tree, and a 3.5-cm radiopaque mass in the right lower quadrant, which is diagnostic for a gallstone impacted at the terminal ileum.
2
Determine the appropriate surgical management.
The treatment of choice is enterolithotomy alone.
The immediate life-saving goal is to relieve the bowel obstruction. A one-stage procedure (including cholecystectomy and fistula repair) carries a very high mortality rate in elderly, frail patients and should only be performed in highly selected, stable patients.

Key Concept

Gallstone ileus diagnosis and surgical management
Question 885Question →

A 31-year-old woman is brought to the emergency department after a high-speed motor vehicle collision. She was an unrestrained front-seat passenger, and her knees forcibly struck the dashboard during the impact. She is in severe distress and complains of excruciating right hip pain. Vital signs are temperature 37.1°C (98.8°F), pulse 105/min, blood pressure 122/78 mm Hg, and respirations 18/min. On physical examination, the right lower extremity is shortened, adducted, and internally rotated. Peripheral pulses are 2+ and symmetric. Neurologic examination reveals decreased sensation to pinprick over the dorsum of the right foot and an inability to actively dorsiflex the right ankle. Anteroposterior radiographs of the pelvis demonstrate a posterior dislocation of the right femoral head with no obvious displaced acetabular or femoral neck fractures. Which of the following is the most appropriate next step in management?

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Answer: Urgent closed reduction of the hip

Answer

The most appropriate next step in management is urgent closed reduction of the hip.
Posterior hip dislocations are orthopedic emergencies. The mechanism (dashboard injury) and presentation (shortened, adducted, internally rotated leg) are classic. The sciatic nerve is frequently stretched or compressed by the displaced femoral head, causing foot drop and dorsal foot numbness. The standard of care is immediate closed reduction (ideally within 6 hours) to relieve pressure on the nerve and significantly reduce the risk of avascular necrosis of the femoral head.

Step-by-Step Solution

1
Identify the injury pattern based on the physical examination and mechanism.
The patient has a shortened, adducted, and internally rotated right lower extremity after a dashboard injury, which is the classic presentation of a posterior hip dislocation.
Recognizing the specific anatomic deformity is necessary to guide emergent management and anticipate potential complications.
2
Correlate the neurologic deficit with the anatomical injury.
Foot drop and dorsal foot numbness indicate a sciatic nerve injury (specifically the peroneal division), which is a known complication of posterior hip dislocations due to posterior displacement of the femoral head.
Understanding the cause of the nerve deficit confirms that the primary problem is mechanical compression or stretch from the dislocated joint.
3
Determine the most appropriate immediate intervention.
Urgent closed reduction is required to relieve tension on the sciatic nerve and restore blood supply to the femoral head.
Delaying reduction for advanced imaging or pursuing unnecessary surgical exploration increases the risk of permanent neurologic disability and avascular necrosis.

Key Concept

Emergent closed reduction of posterior hip dislocations to prevent avascular necrosis and relieve sciatic nerve traction.
Estimated Time:1m 0s
Question 886Question →

During morning rounds, a 74-year-old male is evaluated in the surgical intensive care unit due to progressive dyspnea and mild confusion. The patient is 72 hours status post an uncomplicated Billroth II subtotal gastrectomy for a refractory peptic ulcer. His past medical history is significant for essential hypertension and osteoarthritis. He has received a total of 7.5 L7.5\text{ L} of isotonic crystalloid since the operation and has had a cumulative urine output of 1.8 L1.8\text{ L}. Vital signs demonstrate a temperature of 37.9∘C37.9^\circ\text{C} (100.2∘F100.2^\circ\text{F}), blood pressure of 162/94 mm Hg162/94\text{ mm Hg}, pulse of 118/min118/\text{min}, and respiratory rate of 28/min28/\text{min}. Pulse oximetry shows an oxygen saturation of 87%87\% on room air. Physical examination reveals elevated jugular venous pressure. Lung auscultation demonstrates bilateral basilar crackles and diffuse expiratory wheezing. The abdomen is soft, mildly tender at the incision site, and non-distended, with intact surgical dressings and no erythema. Which of the following are the most appropriate immediate steps in the management of this patient? (Select exactly two options)

Select all that apply

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Answer: Administer intravenous furosemide; Initiate noninvasive positive-pressure ventilation

Answer

The correct management steps are to administer intravenous furosemide and initiate noninvasive positive-pressure ventilation.
The patient is experiencing acute decompensated heart failure due to fluid overload, a classic postoperative complication occurring around days 3 to 4 as third-spaced fluids mobilize back into the intravascular space. The massive positive fluid balance, hypoxia, jugular venous distention, basilar crackles, and wheezing (cardiac asthma) strongly point to cardiogenic pulmonary edema. Initial management includes reducing preload with loop diuretics and providing respiratory support with noninvasive positive-pressure ventilation to immediately improve oxygenation and decrease the work of breathing.

Step-by-Step Solution

1
Analyze the patient's fluid balance and timeline.
The patient received 7.5 L7.5\text{ L} of fluids with only 1.8 L1.8\text{ L} of output and is currently on postoperative day 3.
Third-spaced fluids characteristically mobilize back into the intravascular compartment between postoperative days 3 and 4, greatly increasing the risk of hypervolemia and volume overload.
2
Interpret the physical examination and vital sign findings.
Hypoxia, elevated jugular venous pressure, basilar crackles, and wheezing are identified.
These signs collectively indicate increased right-sided heart pressures and pulmonary edema, confirming a diagnosis of acute decompensated heart failure rather than an infectious or primary pulmonary process.
3
Determine the immediate management for postoperative pulmonary edema.
Select interventions that reduce preload and improve oxygenation.
Intravenous loop diuretics (furosemide) reduce intravascular volume, while noninvasive positive-pressure ventilation improves alveolar gas exchange and reduces the work of breathing.

Key Concept

Postoperative fluid overload and the mobilization of third-spaced fluids (typically occurring on postoperative days 3-4) can precipitate acute decompensated heart failure, requiring acute management with loop diuretics and noninvasive respiratory support.
Question 887Question →

A 45-year-old woman is brought to the emergency department due to progressively worsening abdominal pain. Two days ago, she developed diffuse, crampy abdominal pain associated with nausea and bilious vomiting. Over the past 4 hours, the pain has become severe and constant. She has not passed flatus or stool for 24 hours. Her past medical history is notable for an open abdominal hysterectomy performed four years ago. Her temperature is 38.9°C (102°F), blood pressure is 85/50 mmHg, pulse is 125/min, and respirations are 22/min. Physical examination reveals a distended abdomen that is rigid, with diffuse rebound tenderness and involuntary guarding. Laboratory studies show a leukocyte count of 19,500/mm³ and a serum lactate level of 4.8 mmol/L. Which of the following is the most appropriate next step in management?

Show answer & explanation

Answer: Immediate exploratory laparotomy

Answer

Immediate exploratory laparotomy is the correct next step in management.
The correct action is immediate exploratory laparotomy. This patient's initial presentation (crampy pain, bilious vomiting, obstipation, prior abdominal surgery) is classic for a small bowel obstruction (SBO) caused by postoperative adhesions. However, her clinical status has deteriorated, marked by a transition to severe, constant pain. The presence of fever, hemodynamic instability (hypotension, tachycardia), rigid abdomen with rebound tenderness (peritonitis), pronounced leukocytosis, and lactic acidosis strongly indicates that the SBO has become complicated by bowel ischemia, strangulation, or full perforation. In any patient presenting with an acute abdomen characterized by peritonitis and shock, emergent surgical exploration is the standard of care to resect nonviable tissue and control contamination.

Step-by-Step Solution

1
Identify the underlying primary diagnosis.
The patient has a small bowel obstruction, likely secondary to adhesions from her previous open hysterectomy.
Crampy abdominal pain, bilious vomiting, obstipation, and a history of abdominal surgery are classic presenting symptoms of a mechanical small bowel obstruction.
2
Evaluate the clinical presentation for signs of complications.
The patient exhibits severe, constant pain, fever, hypotension, tachycardia, peritoneal signs (rigidity, rebound tenderness), leukocytosis, and lactic acidosis.
These specific clinical and laboratory markers indicate that the obstruction has progressed to bowel ischemia, strangulation, or perforation.
3
Determine the most appropriate management based on the patient's stability and exam.
The patient requires urgent surgical exploration.
Hemodynamically unstable patients with an acute surgical abdomen (peritonitis) must undergo immediate laparotomy without delaying for further imaging or attempting conservative measures.

Key Concept

Management of complicated small bowel obstruction
Estimated Time:1m 0s
Question 888Question →

Match each clinical trauma presentation with the most appropriate next step in definitive diagnosis or management.

Click a left item, then click its matching right item

Items

35-year-old male with a stab wound to Zone II of the neck, presenting with an expanding pulsatile hematoma and stridor.
45-year-old male in hemorrhagic shock following a motorcycle collision. FAST is negative, CXR is clear, and he remains hypotensive despite a pelvic binder and blood transfusion.
50-year-old male after a high-speed motor vehicle collision with unequal upper extremity blood pressures. He is hemodynamically stable with a widened mediastinum on chest X-ray.
22-year-old male with a severe crush injury to the pelvis. Physical examination reveals blood at the urethral meatus and a high-riding prostate on digital rectal examination.

Matches

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Answer

Stab wound with hard signs matches with immediate surgical exploration; unstable pelvic fracture with negative FAST matches with pelvic angiography with embolization; stable patient with widened mediastinum matches with CT angiography of the chest; pelvic injury with meatal blood matches with retrograde urethrography.
Each presentation maps to a specific therapeutic or diagnostic pathway: hard signs in neck trauma dictate surgery; unstable pelvic bleeding without an intraperitoneal source requires angiography; stable blunt aortic injury requires CT angiography; and signs of urethral injury mandate retrograde urethrography prior to any catheterization attempt.

Step-by-Step Solution

1
Analyze the penetrating neck trauma presentation.
Identify 'hard signs' of aerodigestive and vascular injury.
Hard signs in any zone of the neck dictate immediate operative intervention over diagnostic imaging.
2
Evaluate the hemodynamically unstable blunt trauma patient.
Recognize that hemorrhagic shock with a negative FAST and clear CXR localizes the bleeding to the retroperitoneum.
Laparotomy is ineffective for retroperitoneal bleeding from pelvic fractures; angiography is required.
3
Assess the hemodynamically stable MVC patient.
Identify high suspicion for blunt aortic injury.
Hemodynamic stability permits transportation to the CT scanner for definitive non-invasive imaging.
4
Examine the pelvic crush injury presentation.
Identify contraindications to blind Foley catheterization.
Catheterization can worsen a urethral tear; imaging of the urethra is the required next step.

Key Concept

Algorithms for acute trauma management based on mechanism of injury, anatomic location, and hemodynamic stability.
Question 889Question →

In the emergency trauma setting, acute musculoskeletal injuries frequently compromise adjacent anatomical structures. Match each acute orthopedic injury pattern with its most commonly associated critical neurovascular consequence or expected physical examination finding.

Click a left item, then click its matching right item

Items

Midshaft humeral fracture
Anterior glenohumeral dislocation
Fibular head and neck fracture
Posterior tibiofemoral dislocation

Matches

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Answer

Midshaft humeral fracture matches with weakness in wrist extension. Anterior glenohumeral dislocation matches with flattening of the shoulder contour. Fibular head and neck fracture matches with weakness in ankle dorsiflexion. Posterior tibiofemoral dislocation matches with asymmetrical or absent distal pulses.
Correct matching pairs are derived directly from classical anatomical relationships tested on the USMLE. The radial nerve's course in the spiral groove links it to the midshaft humerus. The axillary nerve's path through the quadrangular space links it to anterior shoulder dislocations. The common fibular nerve's superficial wrap around the fibula dictates its vulnerability in fibular neck fractures. Finally, the rigid fixation of the popliteal artery makes it the most critical structure evaluated following any knee dislocation.

Step-by-Step Solution

1
Analyze the anatomical relationships for a midshaft humeral fracture.
Identify the radial nerve in the spiral groove, leading to wrist and finger extensor weakness.
Structural proximity determines the most likely neurovascular complication.
2
Evaluate the structures at risk during an anterior glenohumeral dislocation.
Identify the axillary nerve wrapping below the joint, affecting deltoid muscle function and lateral sensation.
Anterior and inferior displacement of the humeral head stretches structures in the quadrangular space.
3
Examine the superficial anatomy of the lateral lower leg near the knee.
Recognize the common fibular (peroneal) nerve tightly crossing the fibular neck, leading to foot drop when injured.
Subcutaneous nerves crossing bones are highly vulnerable to direct trauma and fractures.
4
Consider the vascular tethering in major joint dislocations, specifically the knee.
Identify the popliteal artery's fixed nature across the popliteal fossa, making it susceptible to disruption during tibiofemoral dislocation.
Vascular injuries are the most limb-threatening immediate consequence in high-energy knee trauma.

Key Concept

Specific orthopedic injuries reliably predict particular neurovascular deficits based on strict anatomical tethering and proximity of nerves and vessels to bone.
Question 890Question →

A 25-year-old male is brought to the emergency department after falling 20 feet from a roof. He is unconscious, hypotensive, and has obvious facial trauma. Arrange the following steps of his initial assessment and management in the correct chronological order according to Advanced Trauma Life Support (ATLS) protocols.

Drag items to arrange them in the correct order

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Answer

The correct chronological sequence for the ATLS primary survey is: Airway and cervical spine stabilization, Breathing and ventilation, Circulation and hemorrhage control, Disability (neurologic evaluation), and Exposure/environmental control.
The Advanced Trauma Life Support (ATLS) primary survey follows a strict chronological protocol designed to identify and treat the most rapidly fatal injuries first. The sequence is 'ABCDE': Airway maintenance with cervical spine restriction, Breathing and ventilation, Circulation with hemorrhage control, Disability (neurologic status), and Exposure/environmental control. Adhering to this order ensures that hypoxia and severe shock are reversed before focusing on focal neurologic deficits or hidden, less acute injuries.

Step-by-Step Solution

1
Prioritize the airway and cervical spine
Assess airway patency and secure the airway with manual in-line cervical spine stabilization.
Airway compromise is the most rapidly fatal complication in trauma. Cervical spine injury must be assumed in any high-energy blunt trauma.
2
Ensure adequate oxygenation and ventilation
Evaluate chest wall motion, auscultate breath sounds, and apply supplemental oxygen.
Once the airway is patent, oxygen delivery to the lungs must be confirmed to prevent hypoxia.
3
Assess and support hemodynamics
Assess peripheral pulses, control any compressible hemorrhage, and establish large-bore intravenous access.
Hemorrhagic shock is the most common cause of preventable death in trauma; it must be addressed immediately after oxygenation.
4
Perform a rapid neurologic evaluation
Determine the Glasgow Coma Scale score and evaluate bilateral pupillary responses.
A baseline neurologic status is needed to identify traumatic brain injury and signs of increased intracranial pressure.
5
Expose the patient fully
Completely undress the patient to inspect for hidden injuries while actively preventing hypothermia.
Full exposure is necessary to avoid missing hidden trauma, but hypothermia exacerbates trauma-induced coagulopathy and must be prevented.

Key Concept

Advanced Trauma Life Support (ATLS) Primary Survey Sequence
Question 891Question →

A 34-year-old woman is brought to the emergency department after falling approximately 15 feet from a roof. Upon arrival, she is lethargic but responsive to painful stimuli. Her blood pressure is 78/45 mmHg, and her heart rate is 132/min. Oxygen saturation is 96% on room air. Her airway is clear, and breath sounds are present and equal bilaterally. The abdomen appears distended and is tense on palpation. A bedside focused assessment with sonography in trauma (FAST) reveals a significant amount of anechoic fluid surrounding the spleen and liver. Which of the following is the most appropriate next step in management?

Show answer & explanation

Answer: Immediate surgical exploration of the abdomen

Answer

The most appropriate next step is immediate surgical exploration of the abdomen.
The correct answer is immediate surgical exploration because the patient presents with classic signs of hemorrhagic shock following blunt trauma, and the positive ultrasound localizes the bleeding to the peritoneal cavity. In this scenario, time is critical, and immediate operative hemorrhage control is the definitive treatment.

Step-by-Step Solution

1
Assess the patient's hemodynamic status.
The patient is hypotensive (78/45 mmHg) and tachycardic (132/min), indicating hemodynamic instability and shock.
Hemodynamic status determines whether a trauma patient can safely undergo advanced diagnostic imaging or requires immediate intervention.
2
Evaluate the mechanism of injury and primary survey findings.
The patient suffered blunt trauma from a fall. The airway is clear and breathing is equal, pointing toward the abdomen as the source of shock due to distension and tenseness.
Identifying the likely source of hemorrhage directs the focus of the secondary assessment and immediate treatment.
3
Interpret the bedside ultrasound (FAST) results.
The FAST exam is positive, showing anechoic fluid (blood) around the spleen and liver.
A positive FAST in a hemodynamically unstable patient confirms intra-abdominal hemorrhage.
4
Determine the definitive management.
The combination of blunt trauma, hemodynamic instability, and a positive FAST exam mandates emergency surgical intervention.
Immediate operative control of bleeding is life-saving and takes precedence over further diagnostic studies.

Key Concept

Hemodynamically unstable patients with blunt abdominal trauma and a positive FAST exam require immediate exploratory surgery.
Question 892Question →

A 41-year-old man is evaluated on the surgical floor due to a new-onset fever and abdominal discomfort. He is currently on postoperative day 7 following an emergency laparoscopic appendectomy for ruptured appendicitis. The patient was tolerating a regular diet until yesterday, when he developed anorexia, nausea, and a progressively worsening ache in his right lower quadrant. His temperature is 39.2∘C39.2^\circ\text{C} (102.6∘F102.6^\circ\text{F}), pulse is 112/min112/\text{min}, respirations are 18/min18/\text{min}, and blood pressure is 118/76 mm Hg118/76\text{ mm Hg}. Physical examination reveals a mildly distended abdomen with focal deep tenderness in the right lower quadrant. There is no rebound tenderness or guarding. Bowel sounds are hypoactive. The laparoscopic port incisions are clean, dry, and intact with no surrounding erythema, induration, or purulent drainage. Laboratory studies show a leukocyte count of 17,500/mm317,500/\text{mm}^3 with 85%85\% neutrophils. Which of the following is the most appropriate next step in management?

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Answer: Computed tomography scan of the abdomen and pelvis

Answer

Computed tomography scan of the abdomen and pelvis
The correct answer is to obtain a computed tomography (CT) scan of the abdomen and pelvis. This patient's presentation of a high fever, localized abdominal pain, and marked leukocytosis on postoperative day 7 following a contaminated surgery (ruptured appendicitis) is highly suspicious for an intra-abdominal abscess. Deep organ-space infections typically manifest between postoperative days 5 and 7. Because the patient is hemodynamically stable and lacks generalized peritonitis, the standard of care is to confirm the diagnosis and localize the collection using a CT scan. Once identified, the abscess can usually be managed with CT-guided percutaneous drain placement and targeted antibiotics.

Step-by-Step Solution

1
Analyze the patient's postoperative timeline and presentation.
The patient has a high fever, leukocytosis, and focal abdominal pain on postoperative day 7 following an operation for a contaminated field (ruptured appendicitis).
Establishing the postoperative day helps narrow the differential diagnosis for postoperative fever (the '5 Ws'). Deep space infections typically present 5-7 days after surgery.
2
Evaluate the physical examination findings.
The abdominal exam shows focal right lower quadrant tenderness but no generalized peritonitis. The surgical incisions are benign.
The lack of incisional erythema rules out a superficial surgical site infection. The focal deep tenderness points to an intra-abdominal collection.
3
Determine the optimal diagnostic modality.
A CT scan of the abdomen and pelvis with contrast is selected.
CT imaging is highly sensitive for detecting intra-abdominal abscesses and can simultaneously provide a target for therapeutic percutaneous drainage in a stable patient.

Key Concept

Intra-abdominal abscess is a common complication occurring roughly 5 to 7 days after abdominal surgery, particularly in contaminated cases like ruptured appendicitis. Diagnosis is confirmed via CT scan, which can also guide percutaneous drainage.
Question 893Question →

Match the following complex trauma patient presentations with the most appropriate definitive next step in their diagnostic or therapeutic management. Assume all patients have established, secure airways and are receiving appropriate initial fluid resuscitation.

Click a left item, then click its matching right item

Items

A 40-year-old woman is hypotensive (blood pressure 74/40 mm Hg) following a crush injury. Primary survey reveals an unstable pelvic ring. A pelvic binder is applied, and 2 units of uncrossmatched packed red blood cells are given, but severe hypotension persists. FAST examination shows no intraperitoneal fluid.
A 33-year-old man sustains a knife wound to the left 5th intercostal space at the midclavicular line. His hemodynamics are completely stable. Breath sounds are equal bilaterally. FAST examination and initial chest radiograph are unremarkable.
A 27-year-old man sustains a stab wound to the anterior neck at the level of the cricoid cartilage. Hemodynamics are stable. There is no expanding hematoma, and he has no respiratory distress. Subcutaneous emphysema is palpable near the wound.
A 50-year-old man is admitted after a 7,200-volt electrical injury. He has deep, full-thickness burns on his right arm and left leg. An indwelling urinary catheter drains dark, red-brown urine. Hemodynamics are stable.

Matches

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Answer

The correct pairings are: 1) Hypotensive pelvic crush injury + negative FAST matches with Pelvic angiography with embolization. 2) Stable left lower chest stab wound matches with Diagnostic laparoscopy. 3) Stable anterior neck stab wound with subcutaneous emphysema matches with CTA of the neck. 4) High-voltage electrical injury with dark urine matches with IV fluids targeted to 75-100 mL/hr urine output.
Each trauma presentation describes a critical branch point in ATLS algorithms. The pelvic fracture patient requires hemorrhage control outside the peritoneal cavity. The thoracoabdominal stab patient risks a delayed diaphragmatic hernia, requiring direct visualization. The neck trauma patient is stable, permitting safe imaging over unnecessary surgery. The electrical burn patient is suffering from myoglobinuria, changing the resuscitation target to preserve kidney function.

Step-by-Step Solution

1
Analyze the pelvic trauma scenario
Identified hemorrhagic shock driven by a retroperitoneal source.
The patient is unstable despite a pelvic binder and transfusion. The negative FAST effectively rules out significant intraperitoneal bleeding, localizing the life-threatening hemorrhage to the retroperitoneal space, which necessitates angiography/embolization.
2
Evaluate the penetrating chest trauma scenario
Identified the injury in the thoracoabdominal 'box' requiring diaphragmatic assessment.
Any penetrating injury between the nipple line (4th ICS) and the umbilicus risks entering the abdominal cavity. Diaphragmatic injuries are frequently missed on CT and x-ray; therefore, diagnostic laparoscopy is mandated in stable patients.
3
Assess the penetrating neck trauma scenario
Differentiated between 'hard' and 'soft' signs of neck injury.
The presence of subcutaneous emphysema is a soft sign. Because the patient is stable without hard signs (such as pulsatile bleeding, expanding hematoma, or stridor), immediate exploration is avoided in favor of precise non-invasive imaging via CTA.
4
Determine fluid management for the electrical burn
Recognized rhabdomyolysis requiring high-volume flush.
The dark urine indicates myoglobinuria from muscle breakdown beneath the skin. This specific complication of electrical burns requires maintaining a urine output of 75-100 mL/hr to prevent renal tubular obstruction, overriding normal Parkland thermal burn guidelines.

Key Concept

Advanced Trauma Life Support (ATLS) algorithms prioritize interventions based on hemodynamic stability and specific anatomical vulnerability: retroperitoneal pelvic bleeding requires embolization, thoracoabdominal wounds require definitive ruling out of diaphragmatic injury, stable neck wounds require CTA, and electrical burns require aggressive fluid flushing for rhabdomyolysis.

Alternative Method

For the pelvic fracture patient, if angiography is unavailable or severely delayed, preperitoneal pelvic packing in the operating room is an equally valid and rapidly accessible alternative definitive step.
Estimated Time:2m 0s
Question 894Question →

A 62-year-old man presents to the emergency department with a 3-day history of progressively worsening left lower quadrant abdominal pain, subjective fevers, and nausea. He has a history of diet-controlled type 2 diabetes and hypertension. His temperature is 38.6∘C38.6^\circ\text{C} (101.5∘F101.5^\circ\text{F}), blood pressure is 128/82 mm Hg128/82\text{ mm Hg}, pulse is 98/min98/\text{min}, and respirations are 18/min18/\text{min}. Physical examination demonstrates marked tenderness to palpation in the left lower quadrant with localized guarding, but no diffuse rigidity or generalized rebound tenderness. Bowel sounds are hypoactive. Laboratory results show a leukocyte count of 16,500/mm316,500/\text{mm}^3 with a left shift.

Arrange the following management steps in the most appropriate chronological order for this patient's anticipated clinical course.

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Answer

The correct chronological sequence begins with medical stabilization using intravenous fluids and antibiotics, followed by a diagnostic CT scan of the abdomen and pelvis. Upon identification of a large abscess, source control is achieved via percutaneous catheter drainage. Finally, an elective interval sigmoid colectomy is performed 6 to 8 weeks later.
The standard of care for a patient presenting with symptoms of acute complicated diverticulitis relies on a strict algorithmic approach. Immediate priorities are the ABCs, IV fluid resuscitation, and empiric broad-spectrum antibiotics to manage potential sepsis. Once initial stabilization is complete, a contrast-enhanced CT of the abdomen and pelvis is required to visualize any complications. For a Hinchey II presentation (a large pelvic or pericolic abscess, typically defined as >3 to 4 cm), image-guided percutaneous drainage is indicated. This achieves crucial source control while avoiding the severe morbidity of acute surgery in a highly inflamed operative field. After the inflammation subsides (usually 6 to 8 weeks later), the patient undergoes an elective interval sigmoid colectomy to prevent recurrence. The delayed timeline allows the surgeon to perform a primary anastomosis rather than a diverting colostomy.

Step-by-Step Solution

1
Initiate intravenous fluid resuscitation and broad-spectrum intravenous antibiotics.
The patient is hemodynamically supported and systemic bacterial spread is mitigated.
Sepsis protocols and empiric treatment must precede diagnostic imaging in patients presenting with signs of systemic infection and acute abdomen.
2
Obtain a computed tomography (CT) scan of the abdomen and pelvis with intravenous contrast.
The imaging identifies the exact presence, location, and extent of the diverticular complication.
A precise diagnosis is required to determine whether the patient needs conservative medical management, minimally invasive drainage, or emergent surgery.
3
Perform image-guided percutaneous catheter drainage.
The infected pericolic or pelvic fluid collection is successfully evacuated.
This provides essential source control for large abscesses while completely avoiding the high morbidity and stoma risk associated with operating on severely inflamed, friable bowel.
4
Schedule an elective interval sigmoid colectomy.
The diseased bowel segment is removed safely in a controlled, elective setting.
Resection prevents future life-threatening recurrences of complicated diverticulitis; operating in an uninflamed field allows for a primary anastomosis without needing a temporary colostomy.

Key Concept

The sequential management of complicated diverticulitis with a large abscess (Hinchey stage II) prioritizes immediate medical stabilization, CT diagnosis, minimally invasive source control via percutaneous drainage, and delayed definitive surgical resection.
Question 895Question →

A 52-year-old male with a surgical history of an open appendectomy 10 years ago presents with severe, colicky abdominal pain, intractable vomiting, and failure to pass flatus for the past 24 hours. Vital signs reveal a heart rate of 105/min and blood pressure of 115/75 mmHg. Examination shows a distended, tympanitic abdomen without rebound tenderness or guarding. Arrange the following interventions in the most appropriate chronological order for his initial evaluation and management.

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Answer

The correct sequence is to first initiate NPO status and IV fluids, then insert a nasogastric tube, followed by obtaining a CT scan, and finally admitting the patient for serial examinations.
The standard sequence for managing a stable patient with a suspected uncomplicated small bowel obstruction is to first address their volume status (NPO and IV fluids). Next, a nasogastric tube should be placed to relieve the symptoms of obstruction and prevent pulmonary aspiration. Once stabilized and decompressed, it is safe to transport the patient for a CT scan to confirm the diagnosis and verify that there is no bowel compromise. Finally, because there is no evidence of peritonitis, the patient is admitted for conservative, nonoperative management.

Step-by-Step Solution

1
Initiate nil per os (NPO) status and begin intravenous fluid resuscitation.
Restores intravascular volume and improves hemodynamics.
Patients with bowel obstruction are significantly volume-depleted; addressing circulation and hemodynamic stability is always the first step.
2
Insert a nasogastric tube.
Decompresses the stomach.
Relieves symptomatic distension and minimizes the risk of aspirating gastric contents while the patient is supine for subsequent imaging.
3
Obtain a computed tomography (CT) scan of the abdomen and pelvis.
Provides definitive imaging of the obstruction.
Delineates the etiology, locates the transition point, and rules out surgical emergencies such as strangulation or closed-loop obstruction.
4
Admit the patient to the surgical service for serial clinical examinations.
Initiates conservative management.
Uncomplicated small bowel obstructions are typically managed nonoperatively with bowel rest and close observation for any clinical deterioration.

Key Concept

The initial management of an uncomplicated small bowel obstruction strictly prioritizes hemodynamic stabilization, followed by symptomatic bowel decompression, diagnostic imaging, and finally, nonoperative observation.
Question 896Question →

A 41-year-old factory worker is evaluated in the resuscitation bay following an industrial explosion inside an enclosed warehouse. Physical examination reveals singed facial hair, hoarseness, carbonaceous sputum, and extensive blistering over the anterior chest and both upper extremities.

Arrange the following acute management steps in the correct chronological sequence according to standard trauma life support protocols.

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Answer

The correct sequence follows the ATLS primary and secondary survey priorities: Securing the airway (endotracheal intubation) comes first, followed by establishing circulation (IV access), then exposure (removing clothing), and finally the secondary survey (TBSA calculation).
In any trauma or severe burn scenario, management strictly adheres to the ABCDE primary survey. Airway (A) takes absolute precedence, especially in this scenario where signs of inhalation injury (hoarseness, carbonaceous sputum, enclosed space fire) necessitate immediate intubation before glottic edema prevents it. Circulation (C) follows to prepare for required fluid resuscitation. Exposure (E) involves removing clothing to halt the burning process. Only after the primary survey is completed does the secondary survey begin, which includes detailed calculations of burn size (TBSA) to guide the Parkland formula.

Step-by-Step Solution

1
Evaluate the patient for immediate life-threatening airway compromise.
Identify a high risk for impending airway obstruction due to inhalation injury (hoarseness, carbonaceous sputum).
Airway ('A') is the first step in the trauma primary survey and takes absolute precedence.
2
Assess and secure hemodynamic stability.
Prepare for massive fluid resuscitation by establishing large-bore vascular access.
Circulation ('C') is addressed immediately after airway and breathing are secured.
3
Expose the patient completely.
Remove all clothing and jewelry.
Exposure ('E') halts the burning process, prevents constriction from edema, and allows for a complete physical examination.
4
Perform the secondary survey.
Calculate the Total Body Surface Area (TBSA) affected by the thermal injury.
Detailed assessment of the injury extent occurs only after life-threatening primary survey issues are fully managed.

Key Concept

Advanced Trauma Life Support (ATLS) Primary Survey in Burn Management
Question 897Question →

A 64-year-old man is evaluated on the surgical ward due to a change in his clinical status. He was admitted 24 hours ago for a small bowel obstruction secondary to adhesions from a prior open sigmoidectomy. On admission, he reported intermittent, crampy abdominal pain. He was placed on nil per os (NPO) status, and treatment with intravenous fluid resuscitation and nasogastric tube decompression was initiated. Over the past 4 hours, the patient reports that his abdominal pain has worsened, becoming severe and continuous rather than colicky. His temperature is 38.6°C (101.5°F), blood pressure is 105/65 mm Hg, and pulse is 118/min. Physical examination reveals a distended abdomen with focal rigidity, guarding, and marked rebound tenderness in the periumbilical region. Bowel sounds are absent. Laboratory studies show a leukocyte count of 17,500/mm317,500/mm^3 with 15% bands, and a serum lactate level of 4.2 mmol/L4.2 \text{ mmol/L}. Which of the following is the most appropriate next step in the management of this patient?

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Answer: Immediate exploratory laparotomy

Answer

Immediate exploratory laparotomy
The correct answer is immediate exploratory laparotomy. This patient initially presented with an uncomplicated small bowel obstruction (SBO) and was appropriately managed with a trial of conservative therapy (nasogastric decompression, NPO status, intravenous fluids). However, he has now developed the classic triad of findings indicating a strangulated SBO: fever, tachycardia, and continuous, severe abdominal pain (replacing the previous colicky pain). The presence of peritonitis (rigidity, rebound tenderness), marked leukocytosis with bandemia, and lactic acidosis confirms that the bowel has become ischemic. A strangulated bowel obstruction is an absolute surgical emergency. Conservative management must be abandoned immediately in favor of emergent exploratory laparotomy to resect necrotic or compromised bowel, re-establish continuity, and prevent overwhelming sepsis.

Step-by-Step Solution

1
Evaluate the patient's baseline presentation and recent clinical changes.
A patient with an uncomplicated small bowel obstruction has developed severe, continuous pain, fever, tachycardia, and localized peritonitis over a 4-hour period.
Tracking clinical trajectory is essential to identify failure of conservative management.
2
Interpret the objective vital signs and laboratory findings.
The patient demonstrates systemic inflammatory response (fever, tachycardia, severe leukocytosis with a left shift) and tissue hypoperfusion/ischemia (elevated serum lactate).
These findings distinguish a simple obstruction from a strangulated obstruction.
3
Determine the definitive treatment based on the diagnosis of a strangulated small bowel obstruction.
The patient requires emergent surgical exploration to resect ischemic or necrotic bowel.
Conservative management is no longer appropriate and will lead to bowel perforation, sepsis, and death if surgery is delayed.

Key Concept

Recognition and surgical management of a strangulated small bowel obstruction.
Question 898Question →

During bedside rounds in the surgical intensive care unit, a 68-year-old female patient suddenly develops severe shortness of breath and lightheadedness. Her surgical history is significant for a frontotemporal craniotomy performed three days ago to resect a large meningioma. Current vital signs show a temperature of 37.2°C, blood pressure of 76/44 mmHg, pulse of 132/min, and respirations of 28/min. Oxygen saturation is 85% on room air. Physical examination reveals clear lung fields bilaterally and an elevated jugular venous pressure. A stat electrocardiogram demonstrates sinus tachycardia with new-onset T-wave inversions in leads V1−V4V_1-V_4. Arrange the following management steps in the most appropriate chronological order.

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Answer

The correct chronological sequence is to first administer oxygen and IV fluids, then perform a bedside echocardiogram, actively withhold anticoagulation/thrombolytics due to surgical contraindications, proceed with a mechanical thrombectomy, and finally place an IVC filter.
The patient is experiencing a massive pulmonary embolism (PE), defined by a suspected PE presenting with hemodynamic instability. The immediate first step is supportive resuscitation with oxygen and intravenous fluids to maximize right ventricular preload. Because the patient is unstable, transporting her for a CT pulmonary angiogram is contraindicated; instead, a bedside echocardiogram should be obtained to rapidly assess for right ventricular strain. Once massive PE is confirmed, standard therapy is systemic thrombolysis. However, this patient is 3 days postoperative from a craniotomy, which is an absolute contraindication to both thrombolysis and systemic anticoagulation due to the extreme risk of catastrophic intracranial hemorrhage. Therefore, these therapies must be explicitly withheld, and the patient must undergo emergent catheter-directed mechanical thrombectomy (or surgical embolectomy) to clear the obstruction. Finally, to prevent future emboli in a patient who cannot be anticoagulated, an IVC filter must be placed.

Step-by-Step Solution

1
Recognize hemodynamic instability in the setting of a suspected pulmonary embolism
The patient requires immediate bedside resuscitation rather than transport for imaging
Profound hypotension and hypoxia necessitate urgent airway and circulatory management with oxygen and intravenous fluids to maximize right heart preload.
2
Select the appropriate diagnostic modality for an unstable patient
A bedside transthoracic echocardiogram is performed
CT pulmonary angiography is unsafe in unstable patients. Echocardiography can rapidly demonstrate right ventricular strain, confirming the diagnosis of a massive PE.
3
Evaluate for contraindications to standard medical therapy
Systemic thrombolysis and therapeutic anticoagulation are actively withheld
The patient is 3 days postoperative from a craniotomy, which represents an absolute contraindication to thrombolytics and heparin due to the extreme risk of fatal intracranial bleeding.
4
Determine the definitive acute intervention
Catheter-directed mechanical thrombectomy is ordered
Because standard pharmacological interventions are contraindicated, the clot must be removed mechanically or surgically to relieve the right ventricular outflow obstruction and restore cardiac output.
5
Implement secondary prevention
An inferior vena cava (IVC) filter is placed
The patient remains at high risk for subsequent emboli but cannot be therapeutically anticoagulated, making an IVC filter the standard of care for secondary prophylaxis.

Key Concept

Algorithm for Massive Pulmonary Embolism with Absolute Contraindications to Anticoagulation
Estimated Time:2m 0s
Question 899Question →

A 31-year-old woman is evaluated in the emergency department after a paragliding collision with a mountain ridge. Upon arrival, she is lethargic and diaphoretic. Her temperature is 36.4°C (97.5°F), blood pressure is 78/42 mm Hg, pulse is 134/min, and respiratory rate is 24/min. Oxygen saturation is 96% on 15 L/min via non-rebreather mask. The airway is unobstructed, and breath sounds are clear and symmetric bilaterally. There is no active external bleeding. Physical examination reveals a large ecchymosis over the left flank. The abdomen is markedly distended, rigid, and diffusely tender with guarding. A focused assessment with sonography for trauma (FAST) demonstrates a large volume of anechoic fluid in the hepatorenal space (Morison pouch) and splenorenal recess. Intravenous access is rapidly secured and fluid resuscitation is initiated. Which of the following is the most appropriate next step in the management of this patient?

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Answer: Immediate celiotomy

Answer

Immediate celiotomy
The correct answer is immediate celiotomy. This patient presents with class III or IV hemorrhagic shock following severe blunt abdominal trauma. The combination of hemodynamic instability (hypotension, tachycardia) and a positive FAST scan indicating intraperitoneal free fluid (blood) constitutes an absolute indication for immediate surgical exploration. Celiotomy will allow the surgical team to rapidly identify the injured organ (e.g., spleen or liver) and obtain source control of the bleeding.

Step-by-Step Solution

1
Identify the patient's hemodynamic status.
The patient is in hemorrhagic shock, evidenced by severe hypotension (78/42 mm Hg), tachycardia (134/min), and altered mental status (lethargy).
Determining hemodynamic stability is the critical branch point in the blunt abdominal trauma management algorithm.
2
Analyze the physical examination and imaging findings.
The patient has a rigid, distended abdomen and a FAST examination that is positive for significant free fluid in the peritoneal cavity.
A positive FAST in the setting of trauma confirms that the source of the patient's hemorrhagic shock is intra-abdominal bleeding.
3
Determine the definitive management based on established trauma guidelines.
The patient must be transferred directly to the operating room for an immediate celiotomy.
Hemodynamically unstable patients with confirmed intra-abdominal hemorrhage require immediate surgical intervention for bleeding control.

Key Concept

Hemodynamically unstable patients with blunt abdominal trauma and a positive focused assessment with sonography for trauma (FAST) require immediate surgical exploration to control life-threatening hemorrhage.
Question 900Question →

A 13-year-old boy is brought to the pediatric orthopedic clinic by his parents due to a two-month history of a persistent left-sided limp and intermittent, dull pain in his left knee. The pain is worse after walking long distances and improves with rest. He denies any history of trauma, recent illnesses, fevers, or night sweats. He is at the 95th percentile for weight and 60th percentile for height. Vital signs are within normal limits.

On physical examination, the patient has an antalgic gait. Inspection of the left knee reveals no swelling, erythema, or deformity. Palpation of the left knee and thigh elicits no tenderness, and knee range of motion is full and painless. However, when the examiner passively flexes the patient's left hip to 90 degrees, the thigh obligatorily rotates outward. Internal rotation of the left hip is limited compared to the right and elicits mild discomfort. Distal pulses are 2+ bilaterally, and sensation is intact throughout both lower extremities.

Which of the following is the most appropriate next step in management?

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Answer: Bilateral anteroposterior and frog-leg lateral radiographs of the pelvis

Answer

Bilateral anteroposterior and frog-leg lateral radiographs of the pelvis
The correct next step in management is obtaining bilateral anteroposterior and frog-leg lateral radiographs of the pelvis. This patient's demographic profile (obese, adolescent male) and physical exam findings (obligatory external rotation with hip flexion, loss of internal rotation) are pathognomonic for Slipped Capital Femoral Epiphysis (SCFE). Because the obturator nerve provides sensory innervation to both the hip joint capsule and the medial aspect of the knee, patients with SCFE frequently present with isolated referred knee or thigh pain. A normal knee exam in the setting of persistent knee pain should always prompt a careful evaluation of the hip. Plain radiographs are the initial diagnostic modality of choice. Bilateral views are necessary because SCFE occurs bilaterally in 20% to 40% of cases. The frog-leg lateral view is particularly sensitive for detecting early, subtle posterior displacement of the femoral head relative to the femoral neck.

Step-by-Step Solution

1
Analyze the clinical presentation.
The patient is an obese adolescent male presenting with chronic, afebrile knee pain and a limp.
Identifying demographic risk factors (obesity, early adolescence) is crucial for narrowing the pediatric orthopedic differential diagnosis.
2
Correlate symptoms with physical examination findings.
Despite the complaint of knee pain, the knee exam is completely normal. The hip exam reveals restricted internal rotation and obligatory external rotation upon flexion.
This discrepancy indicates that the knee pain is referred from the hip, a classic presentation caused by the shared sensory distribution of the obturator nerve.
3
Formulate a diagnosis and select the initial diagnostic modality.
The clinical picture is highly suspicious for Slipped Capital Femoral Epiphysis (SCFE). The gold standard initial step is plain radiography of the pelvis.
Bilateral anteroposterior and frog-leg lateral views are required to visualize the posterior and inferior displacement of the femoral head. Both hips must be imaged because SCFE presents bilaterally in a significant percentage of patients.

Key Concept

Patients with Slipped Capital Femoral Epiphysis (SCFE) often present with referred knee pain and a normal knee exam; diagnosis requires high clinical suspicion, recognition of restricted internal hip rotation, and bilateral pelvic radiographs.
Estimated Time:1m 15s
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