A 76-year-old hypertensive man who used to smoke 20 cigarettes a day for 40 years but quit 5 years ago presents to his family physician with a painless ulcer on the sole of his left foot, located at the base of his 1st toe. He has a history of pain in his left leg that awakens him at night and is relieved by dangling his foot off the side of the bed. His wife discovered the ulcer last week while doing his usual monthly toenail trimming. On physical exam, palpation of the patient’s pulses reveals the following:
Right foot
Femoral 4+
Popliteal 3+
Dorsalis Pedis 2+
Posterior Tibial 1+
Left foot
Femoral 4+
Popliteal 2+
Dorsalis Pedis 0
Posterior Tibial 0
Pulse detection by Doppler ultrasound revealed decreased flow in the left posterior tibial artery, but no flow could be detected in the dorsalis pedis. What is the most likely principal cause of this patient’s ulcer?
Q62
A trauma 'huddle' is called. Morphine is administered for pain. Low-flow oxygen is begun. A traumatic diaphragmatic rupture is suspected. Infusion of 0.9% saline is begun. Which of the following is the most appropriate next step in management?
Q63
A 66-year-old woman is brought to the emergency department 4 hours after falling and hitting her head while skiing. Initially, she refused treatment, but an hour ago she began to develop a severe headache, nausea, and right leg weakness. She has osteopenia. Her only medication is a daily multivitamin. She has no visual changes and is oriented to person, time, and place. Her temperature is 37.2°C (99°F), pulse is 72/min, respirations are 18/min and regular, and blood pressure is 128/75 mm Hg. Examination shows a 5-cm bruise on the left side of her skull. The pupils are equal, round, and reactive to light and accommodation. Muscle strength is 0/5 in her right knee and foot. Which of the following is the most likely cause of this patient's symptoms?
Q64
A previously healthy 27-year-old man is brought to the emergency department 35 minutes after being involved in a high-speed motor vehicle collision in which he was an unrestrained passenger. He was ambulatory at the accident scene, with stable vital signs and no major external injuries except abrasions to both upper extremities. On arrival, he is alert and oriented. His temperature is 37.3°C (99.1°F), pulse is 88/min, respirations are 14/min, and blood pressure is 128/74 mm Hg. Abdominal examination shows ecchymosis over the upper abdomen, with tenderness to palpation over the left upper quadrant. There is no guarding or rigidity. Rectal examination is unremarkable. A CT scan of the abdomen with intravenous contrast shows a subcapsular splenic hematoma comprising 8% of the surface area, with no contrast extravasation and minimal blood in the peritoneal cavity. Which of the following is the next best step in management?
Q65
A 79-year-old man is brought to the emergency department after he noted the abrupt onset of weakness accompanied by decreased sensation on his left side. His symptoms developed rapidly, peaked within 1 minute, and began to spontaneously resolve 10 minutes later. Upon arrival in the emergency room 40 minutes after the initial onset of symptoms, they had largely resolved. The patient has essential hypertension, type 2 diabetes mellitus, chronic obstructive pulmonary disease, and a 50 pack-year smoking history. He also had an ST-elevation myocardial infarction 3 years ago. His brain CT scan without contrast is reported as normal. Carotid duplex ultrasonography reveals 90% stenosis of the right internal carotid. His transthoracic echocardiogram does not reveal any intracardiac abnormalities. Which of the following interventions is most appropriate for this patient's condition?
Q66
An unconscious middle-aged man is brought to the emergency department. He is actively bleeding from the rectum. He has no past medical history. At the hospital, his pulse is 110/min, the blood pressure is 90/60 mm Hg, the respirations are 26/min, and the oxygen saturation is 96% at room air. His extremities are cold. Resuscitation is started with IV fluids and cross-matched blood arranged. His vitals are stabilized after resuscitation and blood transfusion. His hemoglobin is 7.6 g/dL, hematocrit is 30%, BUN is 33 mg/dL, and PT/aPTT is within normal limits. A nasogastric tube is inserted, which drains bile without blood. Rectal examination and proctoscopy reveal massive active bleeding, without any obvious hemorrhoids or fissure. The physician estimates the rate of bleeding at 2-3 mL/min. What is the most appropriate next step in diagnosis?
Q67
A 25-year-old man comes to the emergency department with right knee pain. He was playing soccer when an opposing player tackled him from the side and they both fell down. He immediately heard a popping sound and felt severe pain in his right knee that prevented him from standing or walking. On physical examination, his right knee is swollen and there is local tenderness, mostly at the medial aspect. External rotation of the right knee elicits a significant sharp pain with a locking sensation. Which of the following structures is most likely injured?
Q68
A 45-year-old man in respiratory distress presents to the emergency department. He sustained a stab to his left chest and was escorted to the nearest hospital. The patient appears pale and has moderate difficulty with breathing. His O2 saturation is 94%. The left lung is dull to percussion. CXRs are ordered and confirm the likely diagnosis. His blood pressure is 95/57 mm Hg, the respirations are 22/min, the pulse is 87/min, and the temperature is 36.7°C (98.0°F). His chest X-ray is shown. Which of the following is the next best step in management for this patient?
Q69
A 22-year-old man presents to the emergency department after being tackled in a game of football. The patient was hit from behind and fell to the ground. After the event, he complained of severe pain in his knee. The patient has a past medical history of anabolic steroid use. His current medications include whey protein supplements, multivitamins, and fish oil. His temperature is 99.5°F (37.5°C), blood pressure is 137/68 mmHg, pulse is 100/min, respirations are 17/min, and oxygen saturation is 98% on room air. On physical exam, you see a muscular young man clutching his knee in pain. The knee is inflamed and erythematous. When valgus stress is applied to the leg, there is some laxity when compared to the contralateral leg. The patient is requesting surgery for his injury. Arthrocentesis is performed and demonstrates no abnormalities of the synovial fluid. Which of the following physical exam findings is most likely to be seen in this patient?
Q70
A 40-year-old sailor is brought to a military treatment facility 20 minutes after being involved in a navy ship collision. He appears ill. He reports a sensation that he needs to urinate but is unable to void. His pulse is 140/min, respirations are 28/min, and blood pressure is 104/70 mm Hg. Pelvic examination shows ecchymoses over the scrotum and perineum. There is tenderness over the suprapubic region and blood at the urethral meatus. Digital rectal examination shows a high-riding prostate. Abdominal ultrasound shows a moderately distended bladder. X-rays of the pelvis show fractures of all four pubic rami. Which of the following is the most likely cause of this patient's symptoms?
Trauma/Emergencies US Medical PG Practice Questions and MCQs
Question 61: A 76-year-old hypertensive man who used to smoke 20 cigarettes a day for 40 years but quit 5 years ago presents to his family physician with a painless ulcer on the sole of his left foot, located at the base of his 1st toe. He has a history of pain in his left leg that awakens him at night and is relieved by dangling his foot off the side of the bed. His wife discovered the ulcer last week while doing his usual monthly toenail trimming. On physical exam, palpation of the patient’s pulses reveals the following:
Right foot
Femoral 4+
Popliteal 3+
Dorsalis Pedis 2+
Posterior Tibial 1+
Left foot
Femoral 4+
Popliteal 2+
Dorsalis Pedis 0
Posterior Tibial 0
Pulse detection by Doppler ultrasound revealed decreased flow in the left posterior tibial artery, but no flow could be detected in the dorsalis pedis. What is the most likely principal cause of this patient’s ulcer?
A. An occluded posterior tibial artery on the left foot
B. An occlusion of the first dorsal metatarsal artery
C. A narrowing of the superficial femoral artery (Correct Answer)
D. An occlusion of the deep plantar artery
E. An absent dorsalis pedis pulse with an absent posterior tibial pulse in the left foot
Explanation: ***A narrowing of the superficial femoral artery***
- The patient's history of **claudication** (pain relieved by dangling the foot) and severely diminished pulses (0 in dorsalis pedis and posterior tibial) in the left foot indicates significant **peripheral artery disease (PAD)**.
- The superficial femoral artery is a common site for atherosclerotic narrowing, which would impede blood flow to the lower leg and foot, leading to **ischemic ulcers**.
*An occluded posterior tibial artery on the left foot*
- While there is diminished flow in the posterior tibial artery, the symptoms like **claudication** and the presence of a **painless ulcer** on the sole of the foot suggest a more proximal and significant arterial obstruction.
- An isolated posterior tibial artery occlusion usually doesn't cause such widespread distal ischemia without involvement of other major arteries.
*An occlusion of the first dorsal metatarsal artery*
- An occlusion here would primarily affect the dorsal aspect of the foot or possibly the first toe, but it is unlikely to cause a **painless ulcer on the sole** of the foot or the described **claudication symptoms**.
- While contributing to local ischemia, it's generally a more distal and less significant cause of such pervasive symptoms.
*An occlusion of the deep plantar artery*
- The deep plantar artery is a branch of the **dorsalis pedis artery** and primarily supplies the plantar arch and toes.
- Its occlusion alone would not explain the severe **claudication** and diffuse absence of pulses in both the dorsalis pedis and posterior tibial arteries.
*An absent dorsalis pedis pulse with an absent posterior tibial pulse in the left foot*
- While this finding is present and crucial, it describes the *result* of significant ischemia in the foot, not the *principal cause*.
- The underlying cause of these absent pulses and the resulting ulcer is a more proximal obstruction in the arterial supply to the lower limb.
Question 62: A trauma 'huddle' is called. Morphine is administered for pain. Low-flow oxygen is begun. A traumatic diaphragmatic rupture is suspected. Infusion of 0.9% saline is begun. Which of the following is the most appropriate next step in management?
A. Chest fluoroscopy
B. Barium study
C. CT of the chest, abdomen, and pelvis (Correct Answer)
D. MRI chest and abdomen
E. ICU admission and observation
Explanation: ***CT of the chest, abdomen, and pelvis***
- A suspected **traumatic diaphragmatic rupture** requires a comprehensive imaging study to assess the diaphragm, surrounding organs, and potential associated injuries.
- **CT scan** of the chest, abdomen, and pelvis provides detailed anatomical information, can identify herniated abdominal contents, and is essential for surgical planning in trauma settings.
*Chest fluoroscopy*
- While fluoroscopy can detect diaphragmatic motion, it is **less sensitive** for identifying tears or herniated contents in the **acute trauma setting**.
- It does not provide the comprehensive view of surrounding organs and associated injuries often needed in trauma.
*Barium study*
- A barium study is primarily used to evaluate the **gastrointestinal tract**, but it is generally **not the initial imaging modality** for diaphragmatic rupture due to its limited ability to visualize the diaphragm itself or other solid organ injuries.
- It would be performed after suspicion is increased or for very specific indications, not as a primary diagnostic tool.
*MRI chest and abdomen*
- While MRI offers excellent soft tissue contrast, its use in **acute trauma** is limited by **longer acquisition times**, potential contraindications with metallic implants (though less common in acute trauma), and lower availability compared to CT.
- CT remains the **gold standard** for rapid, comprehensive imaging in unstable trauma patients.
*ICU admission and observation*
- While observation in the ICU is important for monitoring and supportive care, it is **not the next step for diagnosis** of a suspected diaphragmatic rupture.
- Definitive diagnosis through imaging (CT) is crucial before determining specific management strategies, including potential surgical intervention.
Question 63: A 66-year-old woman is brought to the emergency department 4 hours after falling and hitting her head while skiing. Initially, she refused treatment, but an hour ago she began to develop a severe headache, nausea, and right leg weakness. She has osteopenia. Her only medication is a daily multivitamin. She has no visual changes and is oriented to person, time, and place. Her temperature is 37.2°C (99°F), pulse is 72/min, respirations are 18/min and regular, and blood pressure is 128/75 mm Hg. Examination shows a 5-cm bruise on the left side of her skull. The pupils are equal, round, and reactive to light and accommodation. Muscle strength is 0/5 in her right knee and foot. Which of the following is the most likely cause of this patient's symptoms?
A. Upward brainstem herniation
B. Extracranial herniation
C. Uncal herniation
D. Subfalcine herniation (Correct Answer)
E. Tonsillar herniation
Explanation: ***Subfalcine herniation***
- The patient's presentation with a **traumatic brain injury** followed by **delayed neurological symptoms** including severe headache, nausea, and contralateral leg weakness suggests a mass effect on the brain.
- **Subfalcine herniation** occurs when the **cingulate gyrus** is pushed under the **falx cerebri**, often compressing the **anterior cerebral artery** and causing **contralateral leg weakness** as seen in this patient.
*Upward brainstem herniation*
- This type of herniation typically involves the cerebellum moving upward through the **tentorial incisura**, often presenting with **oculomotor nerve dysfunction** and **loss of consciousness**.
- The patient's mental status is preserved, and she does not exhibit typical signs of brainstem compression.
*Extracranial herniation*
- **Extracranial herniation** refers to brain tissue protruding outside the cranial vault, usually through a **skull defect** or after **craniectomy**.
- This patient has no mention of a skull defect or prior surgery that would predispose her to this type of herniation.
*Uncal herniation*
- **Uncal herniation** involves the medial temporal lobe (uncus) moving over the **tentorium cerebelli**, classically causing ipsilateral **fixed and dilated pupil** due to **oculomotor nerve (CN III) compression**.
- The patient's pupils are equal, round, and reactive to light, which rules out major uncal herniation.
*Tonsillar herniation*
- **Tonsillar herniation** involves the **cerebellar tonsils** descending through the **foramen magnum**, compressing the brainstem and often leading to **respiratory and cardiac irregularities**.
- The patient's vital signs are stable, and she does not have respiratory or cardiac symptoms indicative of tonsillar herniation.
Question 64: A previously healthy 27-year-old man is brought to the emergency department 35 minutes after being involved in a high-speed motor vehicle collision in which he was an unrestrained passenger. He was ambulatory at the accident scene, with stable vital signs and no major external injuries except abrasions to both upper extremities. On arrival, he is alert and oriented. His temperature is 37.3°C (99.1°F), pulse is 88/min, respirations are 14/min, and blood pressure is 128/74 mm Hg. Abdominal examination shows ecchymosis over the upper abdomen, with tenderness to palpation over the left upper quadrant. There is no guarding or rigidity. Rectal examination is unremarkable. A CT scan of the abdomen with intravenous contrast shows a subcapsular splenic hematoma comprising 8% of the surface area, with no contrast extravasation and minimal blood in the peritoneal cavity. Which of the following is the next best step in management?
A. Discharge home and follow up closely
B. Coil embolization of short gastric vessels
C. Exploratory laparotomy and splenectomy
D. Hospitalization and frequent ultrasounds (Correct Answer)
E. Laparoscopic splenectomy
Explanation: ***Hospitalization and frequent ultrasounds***
- The patient has a **small, contained splenic hematoma** (grade I-II) and remains **hemodynamically stable**, which are key indicators for **nonoperative management (NOM)** in blunt splenic trauma. Frequent ultrasounds can monitor for expansion of the hematoma or development of free fluid.
- **Serial physical exams** and **vital signs monitoring** are crucial to detect any signs of splenic injury progression or hemodynamic instability, which would necessitate a change in management.
*Discharge home and follow up closely*
- Discharging a patient with a documented **splenic hematoma**, even if small and stable, carries a significant risk of **delayed rupture** or progression of the injury, making it an unsafe initial management strategy.
- While the patient is currently stable, internal bleeding can worsen rapidly, requiring close observation in a hospital setting for at least 24-48 hours.
*Coil embolization of short gastric vessels*
- **Angioembolization** is typically indicated for **higher-grade splenic injuries** (grades III-V), active contrast extravasation, pseudoaneurysms, or continued bleeding despite nonoperative management.
- In this case, there is **no contrast extravasation** and the injury is low-grade, making embolization an overly aggressive first-line intervention.
*Exploratory laparotomy and splenectomy*
- **Laparotomy** and **splenectomy** are reserved for patients with **hemodynamic instability** that doesn't respond to resuscitation, signs of ongoing significant hemorrhage, or higher-grade injuries unsuitable for nonoperative management.
- The patient is currently **hemodynamically stable** and has a low-grade splenic injury, making immediate surgery unnecessary and potentially leading to higher morbidity without clear benefit.
*Laparoscopic splenectomy*
- Similar to open splenectomy, **laparoscopic splenectomy** is a surgical intervention used for significant splenic injuries that fail nonoperative management or cause hemodynamic instability.
- Given the patient's **stable condition** and low-grade injury, immediate surgical removal of the spleen is not indicated and would remove the opportunity for spleen preservation.
Question 65: A 79-year-old man is brought to the emergency department after he noted the abrupt onset of weakness accompanied by decreased sensation on his left side. His symptoms developed rapidly, peaked within 1 minute, and began to spontaneously resolve 10 minutes later. Upon arrival in the emergency room 40 minutes after the initial onset of symptoms, they had largely resolved. The patient has essential hypertension, type 2 diabetes mellitus, chronic obstructive pulmonary disease, and a 50 pack-year smoking history. He also had an ST-elevation myocardial infarction 3 years ago. His brain CT scan without contrast is reported as normal. Carotid duplex ultrasonography reveals 90% stenosis of the right internal carotid. His transthoracic echocardiogram does not reveal any intracardiac abnormalities. Which of the following interventions is most appropriate for this patient's condition?
A. Carotid stenting (Correct Answer)
B. Warfarin
C. Low molecular weight heparin
D. Hypercoagulability studies
E. Aspirin and clopidogrel
Explanation: ***Carotid stenting***
- The patient experienced a **transient ischemic attack (TIA)** with **90% stenosis of the right internal carotid artery**, which is a high-grade stenosis.
- **Carotid revascularization** is highly recommended for symptomatic patients with **high-grade carotid stenosis** (70–99%) to prevent future strokes.
- Both **carotid endarterectomy (CEA)** and **carotid stenting** are acceptable options. In this elderly patient (79 years) with significant comorbidities (COPD, prior MI, 50 pack-year smoking history), **carotid stenting** may be preferred as it avoids the surgical risks of general anesthesia and neck dissection.
*Warfarin*
- **Warfarin** is primarily used for preventing strokes in patients with **atrial fibrillation** or mechanical heart valves.
- It is **not the first-line treatment** for stroke prevention directly caused by symptomatic carotid artery stenosis.
*Low molecular weight heparin*
- **Low molecular weight heparin (LMWH)** is typically used for acute treatment of **deep vein thrombosis** and **pulmonary embolism**, or in certain acute coronary syndromes.
- It does not address the underlying **structural issue of severe carotid stenosis** for long-term stroke prevention.
*Hypercoagulability studies*
- While hypercoagulability can cause strokes, the patient's symptoms are clearly attributed to **severe carotid stenosis**.
- These studies are usually reserved for patients with strokes of **unexplained etiology**, especially younger patients, or those with unusual clot locations.
*Aspirin and clopidogrel*
- **Dual antiplatelet therapy (aspirin and clopidogrel)** is often used after a TIA or minor stroke, but typically for a limited duration (e.g., 21-90 days), and it is an adjunct to revascularization in severe carotid stenosis.
- Although important for **secondary stroke prevention**, it does not address the critical **90% carotid stenosis** that warrants revascularization.
Question 66: An unconscious middle-aged man is brought to the emergency department. He is actively bleeding from the rectum. He has no past medical history. At the hospital, his pulse is 110/min, the blood pressure is 90/60 mm Hg, the respirations are 26/min, and the oxygen saturation is 96% at room air. His extremities are cold. Resuscitation is started with IV fluids and cross-matched blood arranged. His vitals are stabilized after resuscitation and blood transfusion. His hemoglobin is 7.6 g/dL, hematocrit is 30%, BUN is 33 mg/dL, and PT/aPTT is within normal limits. A nasogastric tube is inserted, which drains bile without blood. Rectal examination and proctoscopy reveal massive active bleeding, without any obvious hemorrhoids or fissure. The physician estimates the rate of bleeding at 2-3 mL/min. What is the most appropriate next step in diagnosis?
A. Exploratory laparotomy with segmental bowel resection
B. Radiolabeled RBC scan
C. Colonoscopy
D. Mesenteric angiography (Correct Answer)
E. EGD
Explanation: ***Mesenteric angiography***
- Mesenteric angiography is indicated for **active lower GI bleeding** when the bleeding rate is high (2-3 mL/min) and colonoscopy is challenging due to massive bleeding. It can localize the source of bleeding and allow for therapeutic embolization.
- The patient's presentation with **massive rectal bleeding**, signs of hypovolemia, and the exclusion of upper GI bleeding (bile without blood in NG tube) points to a lower GI source.
*Exploratory laparotomy with segmental bowel resection*
- This is an **invasive surgical procedure** typically reserved for cases where other less invasive diagnostic and therapeutic methods have failed, or in cases of uncontrolled life-threatening hemorrhage.
- Doing an exploratory laparotomy without clear localization of the bleeding site carries significant risks and may lead to unnecessary bowel resections.
*Radiolabeled RBC scan*
- A radiolabeled RBC scan is a highly sensitive diagnostic tool for **detecting intermittent or slow GI bleeding**, but it requires a very low rate of bleeding (as low as 0.1 mL/min).
- Given the patient's **active and massive bleeding** (2-3 mL/min), a more rapid and precise localization method like angiography is preferred.
*Colonoscopy*
- While colonoscopy is the primary diagnostic tool for lower GI bleeding, it is often **challenging to perform effectively in the presence of massive active bleeding**, as the view can be obscured by blood.
- The patient's hemodynamic instability has been corrected, but the high bleeding rate makes a diagnostic colonoscopy difficult.
*EGD*
- EGD (Esophagogastroduodenoscopy) is used to diagnose **upper GI bleeding**, which has been effectively ruled out by the nasogastric tube draining bile without blood.
- This procedure would not be helpful for localizing a lower GI bleeding source.
Question 67: A 25-year-old man comes to the emergency department with right knee pain. He was playing soccer when an opposing player tackled him from the side and they both fell down. He immediately heard a popping sound and felt severe pain in his right knee that prevented him from standing or walking. On physical examination, his right knee is swollen and there is local tenderness, mostly at the medial aspect. External rotation of the right knee elicits a significant sharp pain with a locking sensation. Which of the following structures is most likely injured?
A. Medial meniscus tear (Correct Answer)
B. Posterior cruciate ligament
C. Medial collateral ligament
D. Anterior cruciate ligament
E. Lateral meniscus tear
Explanation: ***Medial meniscus tear***
- The injury mechanism (tackle from the side) and symptoms (popping sound, severe pain, swelling, locking sensation, and pain on external rotation) are highly characteristic of a **meniscal tear**.
- **Locking** and pain with specific rotational movements are classic signs of a meniscal injury, and the **medial meniscus** is more frequently injured due to its stronger attachment to the **medial collateral ligament** and less mobility.
*Posterior cruciate ligament*
- Injuries to the **PCL** typically result from direct trauma to the anterior aspect of the tibia with the knee flexed, or from hyperextension, neither of which is consistent with the described injury mechanism.
- A torn PCL primarily causes posterior instability of the tibia, and a **locking sensation** is less common.
*Medial collateral ligament*
- An **MCL injury** is usually caused by a valgus stress (force from the side, pushing the knee inward), which could occur from a lateral tackle.
- While it would cause pain and swelling, an isolated MCL injury does not typically present with a **popping sound**, **locking sensation**, or pain exacerbated by **external rotation** in the same manner as a meniscal tear.
*Anterior cruciate ligament*
- **ACL tears** commonly result from non-contact or contact injuries involving sudden deceleration, cutting, or jumping, often accompanied by a **popping sound**.
- While it causes instability and swelling, an ACL tear generally does not present with a **mechanical locking sensation**; rather, patients often complain of feeling the knee "give way."
*Lateral meniscus tear*
- While a **lateral meniscus tear** can also cause popping, pain, and locking, the mechanism described (tackle from the side, implying a valgus force) typically puts more stress on the **medial aspect** of the knee.
- Pain on **external rotation** is more indicative of a medial meniscal injury compared to a lateral one, which would more likely be aggravated by internal rotation.
Question 68: A 45-year-old man in respiratory distress presents to the emergency department. He sustained a stab to his left chest and was escorted to the nearest hospital. The patient appears pale and has moderate difficulty with breathing. His O2 saturation is 94%. The left lung is dull to percussion. CXRs are ordered and confirm the likely diagnosis. His blood pressure is 95/57 mm Hg, the respirations are 22/min, the pulse is 87/min, and the temperature is 36.7°C (98.0°F). His chest X-ray is shown. Which of the following is the next best step in management for this patient?
A. ABG
B. Needle aspiration
C. CT scan
D. Thoracotomy
E. Chest tube insertion (Correct Answer)
Explanation: ***Chest tube insertion***
- The patient presents with **respiratory distress**, a **stab wound to the chest**, and the chest X-ray likely shows a **hemothorax** or **pneumothorax**, as indicated by the dullness to percussion and the imaging description.
- **Chest tube insertion** is the definitive treatment for significant hemothorax or pneumothorax, allowing for drainage of blood/air and lung re-expansion.
*ABG*
- While an **arterial blood gas (ABG)** can provide information about oxygenation and ventilation, it is a diagnostic test and not a primary therapeutic intervention for acute respiratory distress due to chest trauma.
- Addressing the underlying cause (hemothorax/pneumothorax) is paramount before detailed physiologic assessment, which might delay life-saving treatment.
*Needle aspiration*
- **Needle aspiration** (thoracentesis or needle decompression) can be used for simple pneumothorax or small effusions but is generally insufficient for a large hemothorax or tension pneumothorax, especially in a patient with signs of hypovolemic shock (low BP).
- Given the stab wound and patient's unstable status, a more definitive and continuous drainage method is required.
*CT scan*
- A **CT scan** provides detailed imaging but is generally not indicated in an unstable patient with acute chest trauma who likely has a life-threatening condition like hemothorax or pneumothorax.
- Delaying definitive treatment for further imaging in an unstable patient can be detrimental.
*Thoracotomy*
- **Thoracotomy** is an invasive surgical procedure indicated for massive hemothorax (e.g., >1500 mL blood drainage immediately or >200 mL/hr for 2-4 hours) or ongoing hemorrhage not controlled by a chest tube.
- It is a more aggressive step and not the first-line intervention in this scenario, where a chest tube is typically needed first to assess the extent of bleeding and lung re-expansion.
Question 69: A 22-year-old man presents to the emergency department after being tackled in a game of football. The patient was hit from behind and fell to the ground. After the event, he complained of severe pain in his knee. The patient has a past medical history of anabolic steroid use. His current medications include whey protein supplements, multivitamins, and fish oil. His temperature is 99.5°F (37.5°C), blood pressure is 137/68 mmHg, pulse is 100/min, respirations are 17/min, and oxygen saturation is 98% on room air. On physical exam, you see a muscular young man clutching his knee in pain. The knee is inflamed and erythematous. When valgus stress is applied to the leg, there is some laxity when compared to the contralateral leg. The patient is requesting surgery for his injury. Arthrocentesis is performed and demonstrates no abnormalities of the synovial fluid. Which of the following physical exam findings is most likely to be seen in this patient?
A. Anterior displacement of the femur relative to the tibia
B. Severe pain with compression of the patella
C. Anterior displacement of the tibia relative to the femur
D. A palpable click with passive motion of the knee (Correct Answer)
E. Laxity to varus stress
Explanation: ***A palpable click with passive motion of the knee***
- The patient's presentation with a **football injury**, **severe knee pain**, **inflammation**, and **laxity with valgus stress** (suggesting MCL injury) points towards significant knee trauma. A palpable click can indicate a torn meniscus, which is a common accompanying injury in such forceful knee trauma, particularly with a simultaneous MCL tear.
- While the primary injury might involve ligaments, the absence of synovial fluid abnormalities upon arthrocentesis makes a pure ligamentous tear without associated meniscal damage less likely to produce a palpable click, and given the forceful impact, meniscal injury is highly probable.
*Anterior displacement of the femur relative to the tibia*
- This finding would indicate a **posterior cruciate ligament (PCL) injury**, which typically results from a direct blow to the tibiofemoral joint while the knee is in flexion, or a hyperextension injury.
- The mechanism described (hit from behind with valgus stress) and the laxity to valgus stress are not consistent with a PCL injury.
*Severe pain with compression of the patella*
- Severe pain with patellar compression is characteristic of **patellofemoral pain syndrome** or **chondromalacia patellae**, which are typically overuse injuries or degenerative conditions.
- This finding is less likely to be the primary presentation following acute, forceful traumatic injury to the knee resulting in ligamentous laxity.
*Anterior displacement of the tibia relative to the femur*
- This is the classic sign of an **anterior cruciate ligament (ACL) tear**, which is tested using the **Lachman test** or **anterior drawer test**.
- While an ACL tear can occur in football, the described injury mechanism ("hit from behind" and "valgus stress") is more indicative of MCL damage, and an isolated ACL tear does not directly correlate with the valgus laxity observed.
*Laxity to varus stress*
- Laxity to varus stress indicates an injury to the **lateral collateral ligament (LCL)**.
- The clinical presentation specifically mentions laxity with **valgus stress**, which points to a medial collateral ligament (MCL) injury, not an LCL injury.
Question 70: A 40-year-old sailor is brought to a military treatment facility 20 minutes after being involved in a navy ship collision. He appears ill. He reports a sensation that he needs to urinate but is unable to void. His pulse is 140/min, respirations are 28/min, and blood pressure is 104/70 mm Hg. Pelvic examination shows ecchymoses over the scrotum and perineum. There is tenderness over the suprapubic region and blood at the urethral meatus. Digital rectal examination shows a high-riding prostate. Abdominal ultrasound shows a moderately distended bladder. X-rays of the pelvis show fractures of all four pubic rami. Which of the following is the most likely cause of this patient's symptoms?
A. Tearing of the anterior urethra
B. Rupture of the corpus cavernosum
C. Tearing of the posterior urethra (Correct Answer)
D. Tearing of the ureter
E. Rupture of the bladder
Explanation: ***Tearing of the posterior urethra***
- The combination of **pelvic fractures**, **blood at the urethral meatus**, inability to void despite a sensation to do so, and a **high-riding prostate** are classic signs of posterior urethral injury.
- The posterior urethra, particularly the membranous portion, is vulnerable to shear forces and tearing during severe pelvic trauma.
*Tearing of the anterior urethra*
- Anterior urethral injuries are typically associated with a **straddle injury** or direct trauma to the perineum, not necessarily pelvic fractures.
- While blood at the meatus can occur, the **high-riding prostate** and extensive pelvic fractures point away from an isolated anterior injury.
*Rupture of the corpus cavernosum*
- This is usually a result of "penile fracture" during sexual intercourse and presents with sudden pain, detumescence, and a characteristic "eggplant" deformity, which are not described here.
- It does not explain the inability to void, high-riding prostate, or association with pelvic fractures.
*Tearing of the ureter*
- Ureteral injuries are typically associated with penetrating trauma or iatrogenic injury during surgery; they rarely occur with blunt pelvic trauma of this nature.
- Symptoms would include flank pain, hematuria, or urine leakage into the retroperitoneum, not significant urethral bleeding or a high-riding prostate.
*Rupture of the bladder*
- Bladder rupture can be intra- or extraperitoneal and is often associated with pelvic fractures. However, it typically causes gross hematuria and often free fluid in the peritoneum (intraperitoneal rupture) or extravasation into the space of Retzius (extraperitoneal rupture).
- While a distended bladder is noted, the presence of **blood at the urethral meatus** and a **high-riding prostate** strongly implicate urethral injury rather than primarily bladder rupture.
