NEET-PG 2015 - Surgery Practice Questions

Q: What type of respiratory failure is most commonly observed in post-operative patients?

Hypoxemic respiratory failure. ***Hypoxemic respiratory failure*** - **Hypoxemic respiratory failure** (Type I) is characterized by a **PaO2 less than 60 mmHg** with a normal or low PaCO2, often due to **V/Q mismatch** and **shunt**. - Post-operative patients frequently develop **atelectasis**, **pneumonia**, or **pulmonary edema**, leading to impaired gas exchange and reduced oxygenation. - This is the **most commonly observed type** in the immediate post-operative period. *Hypercapnic respiratory failure* - **Hypercapnic respiratory failure** (Type II) is primarily due to **alveolar hypoventilation**, resulting in a **PaCO2 greater than 50 mmHg**. - While it can occur post-operatively, it is less common than hypoxemic failure and is typically seen with significant **sedation**, **neuromuscular blockade**, or severe **obstructive lung disease**. *Mixed respiratory failure* - **Mixed respiratory failure** involves both **hypoxemia** and **hypercapnia**, indicating severe impairment in both oxygenation and ventilation. - Although it can occur in severe post-operative complications, it is not the *most commonly observed initial presentation* compared to isolated hypoxemia. *Perioperative respiratory failure* - **Perioperative respiratory failure** (Type III) occurs specifically in the surgical setting and involves atelectasis from changes in chest wall mechanics. - While this occurs in the post-operative context, the term is less commonly used, and the **underlying mechanism is primarily hypoxemic** in nature.

Q: What is the most common cause of lateral aberrant thyroid tissue?

Metastatic thyroid carcinoma. ***Metastatic thyroid carcinoma*** - **Metastatic papillary thyroid carcinoma** to cervical lymph nodes is the most common cause of lateral aberrant thyroid tissue - The term "lateral aberrant thyroid" is a **historical misnomer** that has been abandoned in modern thyroid surgery - What was previously thought to be ectopic thyroid tissue in lateral neck nodes is virtually always **metastatic disease** - Papillary thyroid carcinoma commonly metastasizes to **regional lymph nodes**, which then contain thyroid follicular cells - This represents **lymph node metastases**, not developmental ectopia *Ectopic thyroid tissue due to developmental anomalies* - True developmental ectopia of thyroid tissue in the **lateral neck is extremely rare to nonexistent** - The thyroid gland originates from the **foramen cecum in the midline** and descends along the thyroglossal duct - Developmental ectopic thyroid occurs in **midline structures** (lingual thyroid, thyroglossal duct remnants), not laterally - The concept of "lateral aberrant thyroid" as a developmental anomaly has been **disproven** *Thyroid tissue in the mediastinum* - Mediastinal thyroid tissue represents **substernal or retrosternal goiter** that has descended into the chest - This describes a different anatomical location (mediastinum vs. lateral neck) - Not related to lateral cervical masses *Lingual thyroid* - Lingual thyroid is ectopic thyroid tissue located at the **base of the tongue** - This is a **midline structure**, not a lateral neck finding - Represents failure of thyroid descent during embryological development

Q: What is the optimal timing for administering antibiotic prophylaxis before surgery?

30-60 minutes before incision. ***30-60 minutes before incision*** - This is the **optimal timing** recommended by WHO, CDC, and major surgical guidelines for most commonly used prophylactic antibiotics (cefazolin, cefuroxime). - Ensures **peak tissue and serum concentrations** are achieved at the time of incision, providing maximum protection against surgical site infections. - Based on **pharmacokinetic principles**: the antibiotic must be present at bactericidal concentrations in tissues when bacterial contamination occurs. - Studies show this timing significantly reduces surgical site infection rates compared to other timings. *Immediately before induction of anesthesia* - While acceptable in some protocols, this may be too early if there is a delay between induction and incision. - Could result in **declining antibiotic levels** by the time the incision is made, especially for antibiotics with shorter half-lives. *2-3 hours before surgery* - This is **too early** for most antibiotics. - Tissue levels may have already **declined below therapeutic concentrations** by the time of incision. - Does not provide adequate protection during the critical period of bacterial contamination. *Immediately after surgery* - This is **treatment, not prophylaxis**. - Offers **no preventive benefit** against intraoperative contamination. - By this time, bacteria introduced during surgery have already adhered to tissues and begun forming biofilms.

Q: Which of the following is NOT a feature of membranous urethral injury?

Perineal butterfly hematoma. ***Perineal butterfly hematoma*** - A **perineal butterfly hematoma** is more characteristic of an injury to the **anterior urethra**, specifically the bulbar urethra, often caused by a straddle injury. - It occurs due to the extravasation of blood into the subcutaneous tissue of the perineum, outlining the shape of a butterfly. *blood at the meatus* - **Blood at the meatus** is a classic sign of urethral injury, regardless of the segment (anterior or posterior). - It indicates disruption of the urethral mucosa and bleeding from the damaged blood vessels. *Retention of urine* - **Retention of urine** can occur due to either a complete or partial urethral transection, preventing normal urine flow. - The inability to void can lead to bladder distension and is a significant symptom in assessing urethral trauma severity. *Pelvic fracture* - **Pelvic fractures** are frequently associated with **membranous urethral injuries** because the membranous urethra is fixed within the pelvic ring. - Shear forces from pelvic trauma can cause the prostatomembranous junction to avulse.

Q: Which of the following statements about Hirschsprung disease is incorrect?

The non-peristaltic affected segment is dilated. ***The non-peristaltic affected segment is dilated*** - In Hirschsprung disease, the **aganglionic segment** is typically **constricted** and **narrow**, not dilated, due to continuous contraction without relaxation. - The healthy colon proximal to the affected segment becomes dilated due to the obstruction caused by the constricted, aganglionic segment. *Absence of Ganglion cells in the involved segment* - This statement is **correct**. Hirschsprung disease is fundamentally characterized by the **absence of intramural ganglion cells** (Meissner and Auerbach plexuses) in a segment of the distal colon. - This aganglionosis results in a failure of relaxation and normal peristalsis in the affected bowel segment. *Swenson, Duhamel, and Soave are surgical procedures for this condition* - This statement is **correct**. These are the classic and most common **pull-through surgical procedures** used to treat Hirschsprung disease. - They involve resecting the aganglionic segment and pulling the normal, ganglionated bowel down to the anus. *Mainly presents in infancy* - This statement is **correct**. Hirschsprung disease is primarily a **congenital condition** and is typically diagnosed in newborns and infants. - Common presenting symptoms include **failure to pass meconium** within the first 24-48 hours of life, abdominal distension, and bilious vomiting.

Q: Under what guidelines is treatment started for a patient presenting with appendicular mass on a CT scan?

Ochsner Sherren Regimen. ***Ochsner Sherren Regimen*** - The **Ochsner Sherren regimen** is a conservative management approach specifically used for patients presenting with an **appendicular mass** (a palpable mass formed by the inflamed appendix, omentum, and small bowel loops). - This regimen involves **nil by mouth**, **intravenous fluids**, **antibiotics**, and **analgesia**, with close observation to allow the inflammation to subside before potential interval appendectomy. *Conservative management and discharge* - While the Ochsner Sherren regimen is a form of conservative management, simply stating "conservative management and discharge" is incomplete and potentially dangerous for a patient with an **appendicular mass**. - **Discharge** is not appropriate without a period of observation and specific medical interventions like antibiotics, as there's a risk of abscess formation or perforation. *Kocher's Regimen* - **Kocher's regimen** is not a recognized treatment protocol for an appendicular mass. - The term "Kocher" is more commonly associated with a **surgical incision** (Kocher incision for cholecystectomy) or a **maneuver** (Kocher maneuver for duodenal mobilization). *Immediate Laparotomy* - **Immediate laparotomy** is generally contraindicated in the presence of a well-formed **appendicular mass**. - Operating on a friable, inflamed mass can disrupt the natural containment, leading to widespread peritonitis and increased morbidity. The Ochsner Sherren regimen aims to cool down the inflammation first.

Q: A 45-year-old female underwent a modified radical mastectomy with axillary clearance for breast cancer. Post-surgery, she is unable to lift her arm above her head. Which nerve is most likely to be injured?

Long thoracic nerve of Bell. ***Long thoracic nerve of Bell*** - Injury to the **long thoracic nerve** (nerve to the serratus anterior) leads to **paralysis of the serratus anterior muscle**. - This muscle is crucial for **upward rotation and protraction of the scapula**, which is essential for arm elevation above the head and preventing **'winging' of the scapula**. *Intercostobrachial nerve* - Injury to the **intercostobrachial nerve** typically causes **sensory loss** or numbness in the medial upper arm. - It does not primarily affect motor function or the ability to lift the arm. *Nerve to latissimus Dorsi* - The **thoracodorsal nerve** innervates the **latissimus dorsi muscle**, which is involved in adduction, extension, and internal rotation of the arm. - Injury to this nerve would impair these movements but not directly prevent arm elevation above the head. *Lateral Pectoral nerve* - The **lateral pectoral nerve** supplies the **pectoralis major muscle**, primarily its clavicular head. - Injury would weaken adduction and flexion of the arm, but the inability to lift the arm above the head strongly points to serratus anterior dysfunction.

Q: A high-riding prostate is indicative of which injury?

Membranous Urethral Injury. ***Membranous Urethral Injury*** - A **high-riding prostate** is a classic sign of **membranous urethral injury**, often resulting from **pelvic fractures**. - The disruption of the **urethra** above the perineal membrane causes the prostate to be displaced superiorly and appear "high." *Extraperitoneal Bladder rupture* - This typically occurs with **pelvic fractures** and involves urine leaking into the **retropubic space**. - While associated with pelvic trauma, it does not directly cause a high-riding prostate; the bladder itself may be ruptured, but the relative position of the prostate is not significantly altered. *Intraperitoneal Bladder Rupture* - This type of rupture usually results from a direct blow to a **full bladder** and involves urine extravasating into the **peritoneal cavity**. - It does not cause a high-riding prostate, as the injury is to the dome of the bladder, not the structures supporting the prostate. *Bulbar Urethral Injury* - A **bulbar urethral injury** usually results from a **straddle injury** and is located in the anterior urethra. - This type of injury does not affect the anatomical position of the prostate, which is posterior and superior to the bulbar urethra.

Q: A 45-year-old male presenting with penile cancer extending up to the glans penis is treated with which of the following surgical options?

Partial penectomy with a 2 cm margin. ***Partial penectomy with a 2 cm margin*** - For **penile cancer** confined to the glans, **partial penectomy** is the standard surgical approach to achieve local control while preserving penile length. - Historically, a **2 cm tumor-free margin** was recommended as the standard of care (reflected in older guidelines and exam questions). - **Modern evidence** suggests that narrower margins of **5-8 mm** are oncologically safe with comparable local control rates, but the **2 cm margin** was the traditional teaching and remains the expected answer for this question context. *Simple circumcision* - **Simple circumcision** is indicated for benign conditions like **phimosis** or **premalignant lesions** (carcinoma in situ), not for invasive cancer. - It does not provide adequate oncological clearance for **invasive penile cancer** and carries a high risk of **local recurrence**. *Partial penectomy with a 4 cm margin* - A **4 cm margin** is excessively radical and would result in unnecessary loss of penile length and function. - Even by historical standards, this exceeds the recommended **2 cm margin** and would cause significant functional and psychological morbidity. *Partial penectomy with inguinal lymph node dissection* - **Inguinal lymph node dissection** is indicated when there is **clinical or radiological evidence of lymph node metastasis** or high-risk pathological features. - Without evidence of nodal involvement, routine prophylactic lymphadenectomy is not performed due to significant morbidity (lymphedema, wound complications). - The question does not specify nodal involvement, making this option unnecessarily aggressive.

Q: Which of the following statements about Branchial cysts is true:

Most common site is lateral neck. ***Most common site is lateral neck*** - **Branchial cleft cysts** typically present as a mass in the **lateral neck**, anterior to the sternocleidomastoid muscle. - They are congenital anomalies resulting from incomplete obliteration of the branchial clefts during embryonic development. *50-70% are seen in lungs* - This statement is incorrect; branchial cysts are **cervical anomalous masses** arising from the branchial apparatus, not primarily found in the lungs. - Lung lesions are more commonly associated with congenital pulmonary airway malformations or bronchogenic cysts, which differ in origin. *They are premalignant lesions* - Branchial cysts are generally **benign lesions** and do not typically transform into malignancy. - While rare cases of carcinoma arising within a branchial cleft cyst have been reported, they are not considered routinely premalignant. *Infection is uncommon in branchial cysts* - Conversely, infection is a **common complication** of branchial cysts, often leading to sudden enlargement, pain, and erythema. - The presence of internal fluid and epithelial lining makes them susceptible to bacterial colonization and subsequent abscess formation.

Question 1

What type of respiratory failure is most commonly observed in post-operative patients?

Accepted Answer

Hypoxemic respiratory failure

Answer

Hypercapnic respiratory failure

Answer

Mixed respiratory failure

Answer

Perioperative respiratory failure

Question 2

What is the most common cause of lateral aberrant thyroid tissue?

Accepted Answer

Metastatic thyroid carcinoma

Answer

Ectopic thyroid tissue due to developmental anomalies

Answer

Thyroid tissue in the mediastinum

Answer

Lingual thyroid

Question 3

What is the optimal timing for administering antibiotic prophylaxis before surgery?

Accepted Answer

30-60 minutes before incision

Answer

Immediately before induction of anesthesia

Answer

2-3 hours before surgery

Answer

Immediately after surgery

Question 4

Which of the following is NOT a feature of membranous urethral injury?

Accepted Answer

Perineal butterfly hematoma

Answer

blood at the meatus

Answer

Retention of urine

Answer

Pelvic fracture

Question 5

Which of the following statements about Hirschsprung disease is incorrect?

Accepted Answer

The non-peristaltic affected segment is dilated

Answer

Absence of ganglion cells in the involved segment

Answer

Mainly presents in infancy

Answer

Swenson, Duhamel, and Soave are surgical procedures for this condition

Question 6

Under what guidelines is treatment started for a patient presenting with appendicular mass on a CT scan?

Accepted Answer

Ochsner Sherren Regimen

Answer

Conservative management and discharge

Answer

Kocher's Regimen

Answer

Immediate Laparotomy

Question 7

A 45-year-old female underwent a modified radical mastectomy with axillary clearance for breast cancer. Post-surgery, she is unable to lift her arm above her head. Which nerve is most likely to be injured?

Accepted Answer

Long thoracic nerve of Bell

Answer

Intercostobrachial nerve

Answer

Nerve to latissimus Dorsi

Answer

Lateral Pectoral nerve

Question 8

A high-riding prostate is indicative of which injury?

Accepted Answer

Membranous Urethral Injury

Answer

Extraperitoneal Bladder rupture

Answer

Intraperitoneal Bladder Rupture

Answer

Bulbar Urethral Injury

Question 9

A 45-year-old male presenting with penile cancer extending up to the glans penis is treated with which of the following surgical options?

Accepted Answer

Partial penectomy with a 2 cm margin

Answer

Simple circumcision

Answer

Partial penectomy with a 4 cm margin

Answer

Partial penectomy with inguinal lymph node dissection

Question 10

Which of the following statements about Branchial cysts is true:

Accepted Answer

Most common site is lateral neck

Answer

50-70% are seen in lungs

Answer

They are premalignant lesions

Answer

Infection is uncommon in branchial cysts

NEET-PG 2015 — Surgery