Minimally invasive oncologic surgery US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Minimally invasive oncologic surgery. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Minimally invasive oncologic surgery US Medical PG Question 1: A 64-year-old woman presents to the surgical oncology clinic as a new patient for evaluation of recently diagnosed breast cancer. She has a medical history of type 2 diabetes mellitus for which she takes metformin. Her surgical history is a total knee arthroplasty 7 years ago. Her family history is insignificant. Physical examination is notable for an irregular nodule near the surface of her right breast. Her primary concern today is which surgical approach will be chosen to remove her breast cancer. Which of the following procedures involves the removal of a portion of a breast?
- A. Arthroplasty
- B. Lumpectomy (Correct Answer)
- C. Vasectomy
- D. Mastectomy
- E. Laminectomy
Minimally invasive oncologic surgery Explanation: ***Lumpectomy***
- A **lumpectomy** is a surgical procedure that removes the **breast cancer tumor** and a small margin of surrounding healthy tissue, preserving most of the breast.
- This procedure is a common treatment for early-stage breast cancer and is often followed by radiation therapy.
*Arthroplasty*
- **Arthroplasty** is a surgical procedure to **repair or replace a joint**, typically due to arthritis or injury.
- The patient's history of a total knee arthroplasty indicates this procedure was performed on her knee, not her breast.
*Vasectomy*
- A **vasectomy** is a surgical procedure for **male sterilization**, involving the cutting and sealing of the vas deferens.
- This procedure is unrelated to breast cancer treatment or breast surgery.
*Mastectomy*
- A **mastectomy** involves the **complete surgical removal of the entire breast**, often including the nipple and areola.
- While it is a breast surgery, it removes the *entire* breast, not just a portion.
*Laminectomy*
- A **laminectomy** is a surgical procedure that removes a portion of the **vertebra (lamina)** to relieve pressure on the spinal cord or nerves.
- This procedure is for spinal conditions and is entirely unrelated to breast cancer surgery.
Minimally invasive oncologic surgery US Medical PG Question 2: A 27-year-old man is brought to the emergency department after a motor vehicle accident. He was the unrestrained driver in a head on collision. The patient is responding incoherently and is complaining of being in pain. He has several large lacerations and has been impaled with a piece of metal. IV access is unable to be obtained and a FAST exam is performed. His temperature is 98.2°F (36.8°C), blood pressure is 90/48 mmHg, pulse is 150/min, respirations are 13/min, and oxygen saturation is 98% on room air. Which of the following is the best next step in management?
- A. Reattempt intravenous access
- B. Obtain intraosseous access (Correct Answer)
- C. Place a central line
- D. Administer oral fluids
- E. Exploratory laparotomy
Minimally invasive oncologic surgery Explanation: ***Obtain intraosseous access***
- The patient is in **hypotensive shock** (BP 90/48 mmHg, HR 150/min) after a severe trauma, and **IV access cannot be obtained**. **Intraosseous (IO) access** provides a rapid and reliable route for fluid and medication administration in emergent situations when peripheral IV access is difficult or impossible.
- While central line placement is also a viable option, **IO access is generally faster and easier to establish** in an emergency setting by a wide range of providers, making it the **best initial step** when peripheral IV fails.
*Reattempt intravenous access*
- Although obtaining IV access is critical, the question states that it "is unable to be obtained," implying initial attempts have failed or are proving too difficult/time-consuming given the patient's critical state.
- Persisting with repeated attempts risks significant delay in resuscitation, which is detrimental for a patient in shock.
*Place a central line*
- A central line provides reliable access for fluid and medication, but its placement is generally **more time-consuming** and technically challenging than IO access, especially in an agitated, unstable patient in a chaotic emergency setting.
- The immediate priority is rapid access for fluids to address the patient's shock, for which IO is superior in terms of speed of establishment.
*Administer oral fluids*
- The patient is **unstable**, **incoherently responding**, and likely has significant internal injuries given the mechanism of injury (head-on collision, impalement).
- Oral fluids would be **ineffective** and potentially dangerous (risk of aspiration) in this critical, hemodynamically unstable patient who requires immediate intravenous fluid resuscitation.
*Exploratory laparotomy*
- While the patient likely has significant internal injuries requiring surgical intervention (impalement, hypovolemic shock), an **exploratory laparotomy** is a definitive treatment step, not the *best next step in management* for immediate resuscitation.
- **Hemodynamic stabilization** with fluid resuscitation must occur *before* or *simultaneously with* definitive surgical intervention to improve survival chances.
Minimally invasive oncologic surgery US Medical PG Question 3: Patient 1 – A 26-year-old woman presents to her primary care physician for an annual exam. She currently does not have any acute concerns and says her health has been generally well. Medical history is significant for asthma, which is managed with an albuterol inhaler. Her last pap smear was unremarkable. She is currently sexually active with one male and consistently uses condoms. She occasionally smokes marijuana and drinks wine once per week. Her mother recently passed away from advanced ovarian cancer. Her sister is 37-years-old and was recently diagnosed with breast cancer and ovarian cancer. Physical examination is remarkable for a mildly anxious woman.
Patient 2 – A 27-year-old woman presents to her primary care physician for an annual exam. She says that she would like to be screened for breast cancer since two of her close friends were recently diagnosed. She noticed she has a small and mobile mass on her left breast, which increases in size and becomes tender around her time of menses. Family history is remarkable for hypertension in the father. The physical exam is significant for a small, well-defined, and mobile mass on her left breast that is not tender to palpation.
Which of the following is the best next step in management for patient 1 and 2?
- A. Patient 1 – Breast ultrasound. Patient 2 – Return in 3 months for a clinical breast exam
- B. Patient 1 – Reassurance. Patient 2 – Breast ultrasound
- C. Patient 1 – CA-125 testing. Patient 2 – BRCA testing
- D. Patient 1 – BRCA testing. Patient 2 – Breast ultrasound (Correct Answer)
- E. Patient 1 – Breast and ovarian ultrasound. Patient 2 – Mammography
Minimally invasive oncologic surgery Explanation: ***Patient 1 – BRCA testing. Patient 2 – Breast ultrasound***
- Patient 1 has a strong family history of early-onset **breast and ovarian cancer** (**mother and sister**), suggesting a high probability of an inherited genetic mutation, such as **BRCA1/2**, which warrants genetic testing.
- Patient 2 presents with a **small, mobile, well-defined breast mass** that is likely benign, and a **breast ultrasound** is the appropriate initial imaging for further characterization in a young woman.
*Patient 1 – Breast ultrasound. Patient 2 – Return in 3 months for a clinical breast exam*
- Patient 1's primary concern is genetic predisposition due to family history, an **ultrasound** is not the initial or primary screening method for future cancer risk.
- Patient 2 has a palpable mass; waiting 3 months for a **clinical breast exam** without initial imaging (ultrasound) is not appropriate for evaluating a new breast lump.
*Patient 1 – Reassurance. Patient 2 – Breast ultrasound*
- Patient 1's family history of **early-onset breast and ovarian cancer** is a significant risk factor; therefore, simple **reassurance** without further investigation is inappropriate.
- While a **breast ultrasound** is appropriate for Patient 2, the recommendation for Patient 1 is incorrect.
*Patient 1 – CA-125 testing. Patient 2 – BRCA testing*
- **CA-125** is a tumor marker primarily used for monitoring ovarian cancer treatment or recurrence, not for initial screening in asymptomatic individuals, especially in a young woman with no active symptoms.
- **BRCA testing** is indicated for Patient 1 due to family history, but not for Patient 2 who has a likely benign breast mass and no significant family history.
*Patient 1 – Breast and ovarian ultrasound. Patient 2 – Mammography*
- Regular **breast and ovarian ultrasounds** are not recommended as primary screening tools for genetic risk in asymptomatic high-risk individuals like Patient 1.
- **Mammography** is less sensitive in young women (under 30) due to higher breast tissue density, making **ultrasound** the preferred initial imaging for Patient 2.
Minimally invasive oncologic surgery US Medical PG Question 4: A 45-year-old man undergoes elective vasectomy for permanent contraception. The procedure is performed under local anesthesia. There are no intra-operative complications and he is discharged home with ibuprofen for post-operative pain. This patient is at increased risk for which of the following complications?
- A. Prostatitis
- B. Seminoma
- C. Testicular torsion
- D. Sperm granuloma (Correct Answer)
- E. Inguinal hernia
Minimally invasive oncologic surgery Explanation: **Sperm granuloma**
- A **sperm granuloma** can occur after vasectomy due to the extravasation of sperm from the severed vas deferens, leading to a foreign body granulomatous reaction.
- This complication presents as a **palpable, tender nodule** at the vasectomy site and is a relatively common long-term issue.
*Prostatitis*
- **Prostatitis** is an inflammation of the prostate gland, and there is no direct mechanistic link or increased risk following a vasectomy.
- It is typically caused by bacterial infection or non-infectious inflammatory processes, unrelated to the **vas deferens** ligation.
*Seminoma*
- **Seminoma** is a type of testicular germ cell tumor, and extensive research has shown no increased risk of developing testicular cancer after vasectomy.
- The procedure does not alter the cellular processes or environment within the testicles that predispose to germ cell tumor formation.
*Testicular torsion*
- **Testicular torsion** is a urological emergency involving the twisting of the spermatic cord, which cuts off blood supply to the testis.
- This condition is not associated with vasectomy; it typically occurs due to an anatomical abnormality (e.g., **bell-clapper deformity**) or trauma.
*Inguinal hernia*
- An **inguinal hernia** is a protrusion of abdominal contents through a weakness in the abdominal wall, specifically in the inguinal canal.
- Vasectomy is a superficial procedure that does not involve manipulating or weakening the abdominal wall in a way that would increase the risk of an inguinal hernia.
Minimally invasive oncologic surgery US Medical PG Question 5: A 68-year-old man presents with a 3-month history of difficulty starting urination, weak stream, and terminal dribbling. The patient has no history of serious illnesses and is not under any medications currently. The patient’s father had prostate cancer at the age of 58 years. Vital signs are within normal range. Upon examination, the urinary bladder is not palpable. Further examination reveals normal anal sphincter tone and a bulbocavernosus muscle reflex. Digital rectal exam (DRE) shows a prostate size equivalent to 2 finger pads with a hard nodule and without fluctuance or tenderness. The prostate-specific antigen (PSA) level is 5 ng/mL. Image-guided biopsy indicates prostate cancer. MRI shows tumor confined within the prostate. Radionuclide bone scan reveals no abnormalities. Which of the following interventions is the most appropriate next step in the management of this patient?
- A. Radiation therapy + androgen deprivation therapy (Correct Answer)
- B. Finasteride + tamsulosin
- C. Chemotherapy + androgen deprivation therapy
- D. Radical prostatectomy + chemotherapy
- E. Radical prostatectomy + radiation therapy
Minimally invasive oncologic surgery Explanation: ***Radiation therapy + androgen deprivation therapy***
- This patient presents with **localized prostate cancer** (tumor confined to the prostate with no evidence of metastasis) that requires definitive treatment.
- The presence of a **hard nodule on DRE** with a **family history of early-onset prostate cancer** (father diagnosed at age 58) suggests potentially **intermediate-risk disease** that may warrant combination therapy.
- **Radiation therapy with androgen deprivation therapy (ADT)** is an evidence-based, guideline-recommended treatment for localized prostate cancer, particularly for intermediate to high-risk cases, and has been shown to improve overall survival and disease-free survival compared to radiation alone.
- This approach is appropriate for a 68-year-old patient and avoids surgical morbidity while providing excellent oncological outcomes.
*Radical prostatectomy + radiation therapy*
- While **radical prostatectomy** is a valid primary treatment for localized prostate cancer, combining it upfront with radiation therapy is **not standard practice**.
- **Adjuvant radiation** is only considered **after surgery** if pathology reveals adverse features such as positive surgical margins, extracapsular extension, or seminal vesicle invasion—findings that cannot be determined preoperatively.
- For localized disease, treatment is either surgery **or** radiation, not both simultaneously.
*Finasteride + tamsulosin*
- **Finasteride** (a 5-alpha-reductase inhibitor) and **tamsulosin** (an alpha-blocker) are used to manage **benign prostatic hyperplasia (BPH)** symptoms.
- These medications do not treat prostate cancer and are inappropriate once malignancy is confirmed by biopsy.
*Chemotherapy + androgen deprivation therapy*
- **Chemotherapy** (e.g., docetaxel) is reserved for **metastatic castration-resistant prostate cancer** or metastatic hormone-sensitive disease.
- This patient has **localized disease** with negative bone scan and MRI showing tumor confined to the prostate, making chemotherapy inappropriate.
*Radical prostatectomy + chemotherapy*
- While **radical prostatectomy** can be appropriate for localized prostate cancer, **chemotherapy** is not used adjuvantly for localized disease without metastasis.
- Chemotherapy is reserved for advanced, metastatic, or castration-resistant disease.
Minimally invasive oncologic surgery US Medical PG Question 6: A 43-year-old woman presents to your clinic for the evaluation of an abnormal skin lesion on her forearm. The patient is worried because her mother passed away from melanoma. You believe that the lesion warrants biopsy for further evaluation for possible melanoma. Your patient is concerned about her risk for malignant disease. What is the most important prognostic factor of melanoma?
- A. Depth of invasion of atypical cells (Correct Answer)
- B. S-100 tumor marker present
- C. Evolution of lesion over time
- D. Age at presentation
- E. Level of irregularity of the borders
Minimally invasive oncologic surgery Explanation: ***Depth of invasion of atypical cells***
- The **Breslow depth**, which measures the vertical thickness of the melanoma from the granular layer of the epidermis to the deepest part of the tumor, is the **single most important prognostic factor** for localized melanoma.
- A greater depth of invasion correlates directly with a higher risk of **metastasis** and a poorer prognosis due to increased likelihood of reaching dermal lymphatics or blood vessels.
*S-100 tumor marker present*
- While **S-100 protein** is a marker expressed in melanoma cells and can be used to detect metastatic disease (e.g., in lymph nodes), its mere presence does not serve as the primary prognostic indicator for the primary lesion itself.
- S-100 reflects the presence of melanoma cells but does not provide information about the **depth or biological aggressiveness** of the initial tumor.
*Evolution of lesion over time*
- The **evolution or change** in a lesion (e.g., in size, shape, color, new symptoms) is a crucial diagnostic criterion for identifying suspicious lesions for biopsy.
- While important for diagnosis, it is not a direct prognostic factor once melanoma is confirmed; the **pathological features** after biopsy, particularly depth, determine prognosis.
*Age at presentation*
- **Age** can influence treatment decisions and overall health status, but it is not the most important independent prognostic factor for melanoma.
- Prognosis is primarily driven by tumor-specific characteristics rather than the patient's age.
*Level of irregularity of the borders*
- **Border irregularity** is one of the ABCDE criteria (Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolving) used to identify suspicious pigmented lesions.
- It is a diagnostic indicator that warrants further investigation but does not independently determine **prognosis** as definitively as the Breslow depth after biopsy.
Minimally invasive oncologic surgery US Medical PG Question 7: Three days after undergoing laparoscopic colectomy, a 67-year-old man reports swelling and pain in his right leg. He was diagnosed with colon cancer 1 month ago. His temperature is 38.5°C (101.3°F). Physical examination shows swelling of the right leg from the ankle to the thigh. There is no erythema or rash. Which of the following is likely to be most helpful in establishing the diagnosis?
- A. D-dimer level
- B. Compression ultrasonography (Correct Answer)
- C. CT pulmonary angiography
- D. Transthoracic echocardiography
- E. Blood cultures
Minimally invasive oncologic surgery Explanation: ***Compression ultrasonography***
- This patient's presentation with **unilateral leg swelling and pain** after surgery, especially given his recent **colon cancer diagnosis** (a hypercoagulable state), is highly suspicious for a **deep vein thrombosis (DVT)**.
- **Compression ultrasonography** is the gold standard, non-invasive imaging modality for diagnosing DVT, allowing direct visualization of thrombi and assessing venous compressibility.
*D-dimer level*
- While a **positive D-dimer** indicates recent or ongoing clot formation, it is **non-specific** and can be elevated in many conditions, including surgery, cancer, and infection.
- A normal D-dimer can rule out DVT in low-probability patients, but a high D-dimer in a high-probability patient (like this case) requires further imaging for confirmation, making it less definitive than ultrasound.
*CT pulmonary angiography*
- This imaging is used to diagnose a **pulmonary embolism (PE)**, which is a complication of DVT, but the primary symptoms here are localized to the leg.
- While PE is a concern, diagnosing the source (DVT) in the leg is the immediate priority for treatment and prevention of future complications.
*Transthoracic echocardiography*
- **Echocardiography** evaluates cardiac structure and function and can sometimes detect large clots in the right heart leading to PE, but it is not the primary diagnostic tool for DVT in the leg.
- It would be done if signs of cardiac strain or shunting associated with acute PE were prominent, which is not the case here.
*Blood cultures*
- **Blood cultures** are used to diagnose **bacteremia or sepsis**, which might explain a fever, but the prominent, unilateral leg swelling and pain are not typical for a primary infectious cause in the leg without local signs of cellulitis or abscess.
- While a low-grade fever is present, the absence of erythema or rash makes a primary infectious etiology less likely than DVT given the risk factors.
Minimally invasive oncologic surgery US Medical PG Question 8: An obese 52-year-old man is brought to the emergency department because of increasing shortness of breath for the past 8 hours. Two months ago, he noticed a mass on the right side of his neck and was diagnosed with laryngeal cancer. He has smoked two packs of cigarettes daily for 27 years. He drinks two pints of rum daily. He appears ill. He is oriented to person, place, and time. His temperature is 37°C (98.6°F), pulse is 111/min, respirations are 34/min, and blood pressure is 140/90 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 89%. Examination shows a 9-cm, tender, firm subglottic mass on the right side of the neck. Cervical lymphadenopathy is present. His breathing is labored and he has audible inspiratory stridor but is able to answer questions. The lungs are clear to auscultation. Arterial blood gas analysis on room air shows:
pH 7.36
PCO2 45 mm Hg
PO2 74 mm Hg
HCO3- 25 mEq/L
He has no advanced directive. Which of the following is the most appropriate next step in management?
- A. Comfort care measures
- B. Cricothyroidotomy (Correct Answer)
- C. Tracheostomy
- D. Intramuscular epinephrine
- E. Tracheal stenting
Minimally invasive oncologic surgery Explanation: ***Correct: Cricothyroidotomy***
- This patient has **impending complete airway obstruction** evidenced by inspiratory stridor, severe tachypnea (34/min), hypoxia (O2 sat 89%), and a large obstructing laryngeal mass
- **Cricothyroidotomy** is the emergent surgical airway procedure of choice when there is **imminent or actual complete upper airway obstruction** and endotracheal intubation cannot be safely performed
- The subglottic mass makes endotracheal intubation **extremely dangerous** - instrumentation could precipitate complete obstruction and inability to ventilate
- Cricothyroidotomy provides **immediate airway access** (can be performed in 30-60 seconds) below the level of obstruction, making it life-saving in this emergency
- In the "cannot intubate, cannot ventilate" scenario, cricothyroidotomy is the definitive emergency intervention per ATLS and airway management guidelines
*Incorrect: Tracheostomy*
- While tracheostomy provides definitive airway management, it is a **controlled, elective procedure** typically performed in the OR that takes 20-30 minutes
- This patient requires **immediate airway access** - waiting for OR setup and performing tracheostomy risks complete airway collapse and death
- Tracheostomy may be performed later as a planned procedure once the airway is secured with cricothyroidotomy
- The presence of stridor indicates **critical airway narrowing** requiring emergency intervention, not elective surgery
*Incorrect: Comfort care measures*
- The patient is **alert and oriented** without an advanced directive indicating wishes for comfort care only
- This is an **acute, reversible condition** with appropriate emergency airway intervention
- Presumed consent applies in life-threatening emergencies when the patient cannot formally consent but intervention would be life-saving
- Comfort care would be inappropriate without documented patient wishes or irreversible terminal condition
*Incorrect: Intramuscular epinephrine*
- Epinephrine is indicated for **anaphylaxis** or angioedema causing airway edema from allergic/inflammatory mechanisms
- This patient has **mechanical obstruction** from a solid tumor mass, which will not respond to epinephrine
- Epinephrine causes vasoconstriction and reduces mucosal edema but cannot reduce tumor mass
- Would delay definitive airway management and not address the underlying problem
*Incorrect: Tracheal stenting*
- Tracheal stenting requires **bronchoscopy** in a controlled setting and is used for palliation of tracheal narrowing
- Cannot be performed emergently in an unstable patient with impending airway obstruction
- The obstruction is at the **laryngeal/subglottic level**, not typically amenable to emergency stenting
- Requires time for procedure setup and sedation, which this patient cannot afford given the critical airway emergency
Minimally invasive oncologic surgery US Medical PG Question 9: A 47-year-old man is admitted to the emergency room after a fight in which he was hit in the head with a hammer. The witnesses say that the patient initially lost consciousness, but regained consciousness by the time emergency services arrived. On admission, the patient complained of a diffuse headache. He opened his eyes spontaneously, was verbally responsive, albeit confused, and was able to follow commands. He could not elevate his left hand and leg. He did not remember the events prior to the loss of consciousness and had difficulty remembering information, such as the names of nurses or doctors. His airway was not compromised. The vital signs are as follows: blood pressure, 180/100 mm Hg; heart rate, 59/min; respiratory rate, 12/min; temperature 37.0℃ (98.6℉); and SaO2, 96% on room air. The examination revealed bruising in the right frontotemporal region. The pupils are round, equal, and show a poor response to light. The neurologic examination shows hyperreflexia and decreased power in the left upper and lower limbs. There is questionable nuchal rigidity, but no Kernig and Brudzinski signs. The CT scan is shown in the image. Which of the following options is recommended for this patient?
- A. Lumbar puncture
- B. Decompressive craniectomy
- C. Administration of levetiracetam
- D. Administration of methylprednisolone
- E. Surgical evacuation of the clots (Correct Answer)
Minimally invasive oncologic surgery Explanation: ***Surgical evacuation of the clots***
- The CT scan image shows a **biconvex (lenticular) hyperdensity** consistent with an **epidural hematoma (EDH)**, which typically results from arterial bleeding (often from the **middle meningeal artery**). This patient's **"lucid interval"** (initial loss of consciousness, regain consciousness, then deterioration) is classic for EDH.
- Given the patient's neurological deterioration (left-sided weakness, pupillary changes, confusion, memory issues) and signs of increased intracranial pressure (hypertension, bradycardia - part of Cushing's triad), urgent surgical evacuation of the hematoma is indicated to relieve pressure and prevent herniation.
*Lumbar puncture*
- A lumbar puncture is **contraindicated** in the setting of suspected or confirmed **increased intracranial pressure (ICP)**, as it can precipitate **cerebral herniation**.
- The CT scan clearly demonstrates a space-occupying lesion, making a lumbar puncture unnecessary and potentially dangerous.
*Decompressive craniectomy*
- While decompressive craniectomy is a neurosurgical procedure used to reduce ICP, it is generally considered when other measures have failed or in cases of **diffuse brain swelling** or large **intracerebral hematomas** not amenable to simple evacuation.
- In this case of a localized epidural hematoma with a clear surgical target, direct evacuation is the primary and most effective intervention.
*Administration of levetiracetam*
- Levetiracetam is an **anticonvulsant** used to prevent seizures. While seizures can occur after traumatic brain injury, there is no indication that the patient is currently seizing.
- Prophylactic anticonvulsants are sometimes used in severe TBI, but addressing the life-threatening hematoma takes **precedence** over seizure prophylaxis.
*Administration of methylprednisolone*
- **Corticosteroids** like methylprednisolone are generally **contraindicated** in traumatic brain injury (TBI) as studies have shown **worse outcomes** and increased mortality.
- They are primarily used for their **anti-inflammatory effects** in conditions like spinal cord injury or vasogenic edema from tumors, not for acute head trauma with hematoma.
Minimally invasive oncologic surgery US Medical PG Question 10: A 28-year-old woman is brought to the emergency department 30 minutes after being involved in a high-speed motor vehicle collision in which she was the unrestrained driver. On arrival, she is semiconscious and incoherent. She has shortness of breath and is cyanotic. Her pulse is 112/min, respirations are 59/min, and blood pressure is 128/89 mm Hg. Examination shows a 3-cm (1.2-in) laceration on the forehead and multiple abrasions over the thorax and abdomen. There is crepitation on palpation of the thorax on the right. Auscultation of the lung shows decreased breath sounds on the right side. A crunching sound synchronous with the heartbeat is heard best over the precordium. There is dullness on percussion of the right hemithorax. The lips and tongue have a bluish discoloration. There is an open femur fracture on the left. The remainder of the examination shows no abnormalities. Arterial blood gas analysis on room air shows:
pH 7.31
PCO2 55 mm Hg
PO2 42 mm Hg
HCO3- 22 mEq/L
O2 saturation 76%
The patient is intubated and mechanically ventilated. Infusion of 0.9% saline is begun. Which of the following is the most likely diagnosis?
- A. Pulmonary embolism
- B. Flail chest
- C. Tension pneumothorax
- D. Bronchial rupture (Correct Answer)
- E. Hemopneumothorax
Minimally invasive oncologic surgery Explanation: ***Bronchial rupture***
- The presence of a **mediastinal crunching sound (Hamman's sign)** synchronous with the heartbeat, along with **subcutaneous emphysema (crepitation)** and a significant mechanism of injury (high-speed MVA), points strongly towards a bronchial injury.
- **Decreased breath sounds** and **dullness to percussion** on the right side, combined with severe hypoxemia and hypercapnia, suggest a major airway disruption leading to air trapping and potential collapse of the lung.
*Pulmonary embolism*
- While pulmonary embolism can cause **dyspnea** and **hypoxemia**, it typically presents with clear lung auscultation and does not cause **crepitation** or a **mediastinal crunching sound**.
- The mechanism of injury and immediate onset of symptoms are more consistent with a traumatic injury rather than an embolic event.
*Flail chest*
- **Flail chest** involves paradoxical movement of a segment of the chest wall due to multiple rib fractures, which would lead to respiratory distress and crepitation.
- However, flail chest does not typically cause a **mediastinal crunching sound** or the severe degree of hypoxemia and hypercapnia seen with a major airway injury without other concomitant severe lung injury.
*Tension pneumothorax*
- A **tension pneumothorax** would cause severe respiratory distress, diminished breath sounds, and tracheal deviation (which is not described).
- While it can cause crepitation (subcutaneous emphysema) and hypoxemia, it usually presents with **hyperresonance** to percussion, not dullness, and does not produce a **mediastinal crunching sound** as prominently.
*Hemopneumothorax*
- A **hemopneumothorax** would explain **decreased breath sounds** and **dullness to percussion** due to the presence of blood and air in the pleural space.
- However, it would not typically cause a **mediastinal crunching sound** (Hamman's sign), which is highly specific for pneumomediastinum, often secondary to tracheobronchial injury.
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