General Surgery Principles — MCQs

General Surgery Principles Indian Medical PG Practice Questions and MCQs

Question 721: A Heimlich valve is used for the drainage of which condition?

A. Pneumothorax (Correct Answer)
B. Hemothorax
C. Empyema
D. Malignant pleural effusion

Explanation: ### Explanation **Correct Answer: A. Pneumothorax** The **Heimlich valve** (also known as a flutter valve) is a small, one-way rubber valve designed for the management of **pneumothorax**. It consists of a rubber sleeve inside a plastic casing that opens during expiration (allowing air to escape the pleural space) and collapses during inspiration (preventing air from re-entering). The primary advantage of this device is **patient mobility**. Unlike a traditional underwater seal drain (Bulau drain), it does not require a bulky collection bottle or suction, allowing for outpatient management of simple or tension pneumothoraces. **Why the other options are incorrect:** * **B. Hemothorax:** Blood is viscous and prone to clotting. A Heimlich valve is narrow and can easily become occluded by clots, leading to a tension pneumothorax. Large-bore chest tubes with underwater seal drainage are required. * **C. Empyema:** Pus is thick and contains debris. This would quickly clog the flutter valve mechanism, making it ineffective and dangerous. * **D. Malignant pleural effusion:** These require large-volume drainage or pleurodesis. While indwelling pleural catheters (like PleurX) are used for home management, the Heimlich valve is specifically designed for air, not chronic fluid accumulation. **High-Yield Clinical Pearls for NEET-PG:** * **Directionality:** The most common error in clinical practice is connecting the valve backward; the "blue" or "nozzle" end must point away from the patient. * **Tension Pneumothorax:** While the Heimlich valve can treat it, the immediate emergency management is **needle decompression** (traditionally 2nd ICS in MCL, though ATLS 10th ed. now recommends the 4th/5th ICS mid-axillary line). * **Indication:** It is ideal for "spontaneous pneumothorax" in stable patients to avoid prolonged hospitalization.

Question 722: What is the most common cause of mediastinitis?

A. Tracheal rupture
B. Esophageal rupture (Correct Answer)
C. Drugs
D. Idiopathic

Explanation: **Explanation:** **Mediastinitis** is a life-threatening inflammatory condition of the mediastinum, most commonly caused by an infection. **Why Esophageal Rupture is Correct:** Esophageal perforation (Option B) is the **most common cause** of acute mediastinitis. The esophagus lacks a serosal layer, allowing luminal contents (saliva, gastric acid, and bacteria) to leak directly into the mediastinal space. This leads to rapid chemical irritation followed by polymicrobial infection. The most frequent site of perforation is the left posterolateral aspect of the distal esophagus (**Boerhaave Syndrome**) or iatrogenic injury during endoscopy. **Analysis of Incorrect Options:** * **Tracheal Rupture (A):** While it can cause pneumomediastinum, it is a much rarer cause of clinical mediastinitis compared to the esophagus, as the tracheobronchial tree is relatively sterile compared to the upper GI tract. * **Drugs (C):** Certain drugs (e.g., drug-induced esophagitis) can cause inflammation, but they do not typically lead to mediastinitis unless they cause a full-thickness perforation. * **Idiopathic (D):** Chronic fibrosing mediastinitis can sometimes be idiopathic, but acute mediastinitis almost always has a clear precipitating event (trauma, surgery, or perforation). **NEET-PG High-Yield Pearls:** * **Most common iatrogenic cause:** Endoscopy/instrumentation. * **Clinical Triad (Mackler’s Triad):** Vomiting, chest pain, and subcutaneous emphysema (pathognomonic for Boerhaave Syndrome). * **Hamman’s Sign:** A "crunching" sound heard over the precordium synchronous with the heartbeat, indicating mediastinal emphysema. * **Radiology:** Chest X-ray may show a widened mediastinum or "V-sign of Naclerio." * **Mortality:** Extremely high if treatment is delayed beyond 24 hours.

Question 723: A pressure sore extends into the subcutaneous tissue but underlying structures are not involved. What is the stage of this pressure sore?

A. Stage 1
B. Stage 2
C. Stage 3 (Correct Answer)
D. Stage 4

Explanation: **Explanation:** Pressure sores (decubitus ulcers) are staged based on the depth of tissue destruction. The correct answer is **Stage 3** because it involves **full-thickness skin loss** extending into the **subcutaneous tissue**, but without involving the underlying fascia, muscle, or bone. **Breakdown of Stages:** * **Stage 1:** Non-blanchable erythema of intact skin. The skin is not broken, but there is localized redness (usually over a bony prominence). * **Stage 2:** Partial-thickness skin loss involving the epidermis, dermis, or both. It clinically presents as a shallow open ulcer with a red-pink wound bed or as an intact/ruptured serum-filled blister. * **Stage 3 (Correct):** Full-thickness tissue loss. Subcutaneous fat may be visible, but bone, tendon, or muscle are **not** exposed. Slough may be present but does not obscure the depth of tissue loss. * **Stage 4:** Full-thickness tissue loss with **exposed bone, tendon, or muscle**. Osteomyelitis or osteitis may occur. **High-Yield Clinical Pearls for NEET-PG:** 1. **Unstageable:** If the wound bed is covered by slough (yellow, tan, gray, green, or brown) or eschar (tan, brown, or black), the true depth cannot be determined until it is debrided. 2. **Most Common Sites:** Sacrum (most common overall), followed by the greater trochanter and ischial tuberosity. 3. **Prevention:** The most effective preventive measure is frequent repositioning (every 2 hours) and using pressure-relieving devices (e.g., air mattresses). 4. **Deep Tissue Injury:** Purple or maroon localized area of discolored intact skin or blood-filled blister due to damage of underlying soft tissue from pressure/shear.

Question 724: What is the best treatment for gas gangrene?

A. Surgical debridement
B. Debridement with tetanus toxin
C. Debridement with IV penicillin (Correct Answer)
D. Debridement with polyvalent antitoxin

Explanation: **Explanation:** Gas gangrene (Clostridial Myonecrosis) is a life-threatening, rapidly progressive infection caused primarily by *Clostridium perfringens*. The management strategy is built on the principle that this is a surgical emergency requiring both mechanical removal of necrotic tissue and targeted antimicrobial therapy. **Why Option C is Correct:** The cornerstone of treatment is **emergency surgical debridement** (to remove the anaerobic environment and necrotic muscle) combined with **high-dose IV Penicillin G**. Penicillin remains the drug of choice because *Clostridia* are highly sensitive to it. Often, Clindamycin is added to inhibit the production of bacterial exotoxins, but the standard "best" answer in surgical textbooks remains debridement plus Penicillin. **Analysis of Incorrect Options:** * **Option A:** While debridement is the most critical step, surgery alone is insufficient. Antibiotics are mandatory to control the systemic spread of the infection. * **Option B:** Tetanus toxoid/antitoxin is used for prophylaxis against *Clostridium tetani*. While wound management includes tetanus prophylaxis, it does not treat the active myonecrosis caused by *C. perfringens*. * **Option C:** Polyvalent antitoxin (Gas Gangrene Antitoxin) was historically used but is now considered **ineffective** and is no longer recommended in modern clinical practice due to high risk of serum sickness and lack of proven benefit. **High-Yield NEET-PG Pearls:** * **Clinical Sign:** "Crepitus" on palpation and "Dishwater pus" (serosanguinous discharge) with a sickly sweet odor. * **X-ray Finding:** Feather-like appearance of muscles due to gas (CO2 and H2) between muscle fibers. * **Hyperbaric Oxygen (HBO):** Often used as an adjunct to increase tissue oxygen tension, which is lethal to anaerobic *Clostridia*. * **Incubation Period:** Very short, typically < 24 hours.

Question 725: All of the following are false regarding Vacuum Assisted Closure, EXCEPT?

A. Due to negative pressure, bacterial counts decrease and cell proliferation increases in the wound. (Correct Answer)
B. Continuous pressure of +125 mm Hg is applied.
C. It causes interstitial edema, thereby increasing blood flow and promoting better healing.
D. Suitable for use over malignancy if present in the wound.

Explanation: **Explanation:** Vacuum-Assisted Closure (VAC), also known as Negative Pressure Wound Therapy (NPWT), is a sophisticated wound management system that utilizes controlled sub-atmospheric pressure to promote healing. **Why Option A is Correct:** The application of negative pressure creates a mechanical strain on the wound bed (macrostrain and microstrain). This mechanical stimulus triggers **cell proliferation** and angiogenesis. Simultaneously, the continuous removal of wound exudate and debris leads to a significant **reduction in bacterial colonization** and bioburden, creating an optimal environment for granulation tissue formation. **Analysis of Incorrect Options:** * **Option B:** The standard therapeutic pressure used in VAC is **negative pressure** (sub-atmospheric), typically **-125 mm Hg**, not positive pressure. * **Option C:** VAC actually **reduces interstitial edema** by actively removing excess fluid. Reducing edema decreases localized capillary compression, which subsequently **increases microvascular blood flow** to the wound. * **Option D:** Malignancy in the wound is a **strict contraindication** for VAC. Because VAC stimulates cellular proliferation and angiogenesis, it can potentially accelerate tumor growth or spread. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** It works via "Microdeformation" (cell stretching) and "Macrodeformation" (wound contraction). * **Contraindications:** Malignancy, untreated osteomyelitis, non-enteric/unexplored fistulas, and necrotic tissue with eschar. * **Safety:** Never place the foam directly over exposed major blood vessels or organs due to the risk of erosion and hemorrhage. * **Components:** Sterile open-cell foam dressing, adhesive semi-occlusive drape, and a suction pump.

Question 726: What is true regarding 10-0 sutures?

A. Thicker than 1-0 sutures
B. Synthetic sutures (Correct Answer)
C. Diameter is 0.9 mm
D. Stronger than 1-0 sutures

Explanation: **Explanation:** The sizing of surgical sutures is governed by the **United States Pharmacopeia (USP)** standards. Understanding the numbering system is crucial for surgical practice and exam preparation. **1. Why "Synthetic sutures" is correct:** Sutures as fine as **10-0** are almost exclusively made from synthetic materials such as **Nylon (Ethilon)** or **Polypropylene (Prolene)**. Natural materials like silk or catgut cannot be manufactured to such microscopic diameters while maintaining sufficient tensile strength. These ultra-fine synthetic monofilaments are essential in microsurgery to minimize tissue trauma and inflammatory response. **2. Why the other options are incorrect:** * **Options A & D (Thicker/Stronger than 1-0):** In the USP system, as the number of "zeros" increases, the diameter and tensile strength decrease. Therefore, a **10-0** suture is significantly **thinner and weaker** than a **1-0** (also written as 0) suture. 1-0 is used for heavy tissue like fascia, while 10-0 is used for delicate structures. * **Option C (Diameter is 0.9 mm):** The diameter of a 10-0 synthetic suture is approximately **0.02 mm** (20 micrometers). A diameter of 0.9 mm would correspond to a very thick suture, such as a size 5. **High-Yield Clinical Pearls for NEET-PG:** * **Common Use:** 10-0 sutures are the gold standard for **ophthalmic surgery** (e.g., corneal repair) and **microvascular anastomosis** (nerves and small vessels). * **The "Zero" Rule:** * Numbers without zeros (1, 2, 3...) = Increasing thickness. * Numbers with zeros (2-0, 3-0... 10-0) = Decreasing thickness. * **Memory Aid:** Think of "0" as a negative sign; the more "zeros" you add, the smaller the suture becomes. * **Smallest Suture:** 11-0 and 12-0 are the smallest available, used in ultra-fine microscopic work.

Question 727: Capitonnage is used in the treatment of which of the following conditions?

A. Choledochal cyst
B. Dermoid cyst
C. Hydatid cyst (Correct Answer)
D. Renal cyst

Explanation: **Explanation:** **Capitonnage** is a surgical technique specifically used in the management of **Hydatid cysts** (caused by *Echinococcus granulosus*), most commonly in the liver or lungs. After the cyst contents and the germinal layer (endocyst) are evacuated, a residual cavity remains. Capitonnage involves obliterating this "dead space" by suturing the walls of the redundant pericyst from the inside out. This prevents the accumulation of serum or bile, which reduces the risk of post-operative abscess formation and biliary fistulas. **Analysis of Options:** * **A. Choledochal cyst:** These are congenital dilatations of the biliary tree. Treatment typically involves complete excision of the cyst followed by biliary reconstruction (e.g., Roux-en-Y Hepaticojejunostomy), not cavity obliteration. * **B. Dermoid cyst:** These are germ cell tumors containing adnexal structures. Treatment is simple surgical excision (cystectomy). * **D. Renal cyst:** Simple renal cysts are usually asymptomatic and left alone; if large or symptomatic, they are treated via aspiration or laparoscopic de-roofing (marsupialization), not capitonnage. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic for Hydatid Surgery:** The steps are Protect (with hypertonic saline/scolicidal agents), Aspirate, Re-evacuate, and Obliterate (Capitonnage). * **Scolicidal agents:** Hypertonic saline (20%) is most common; Cetrimide and Silver Nitrate are also used. Formalin is avoided due to the risk of sclerosing cholangitis. * **PAIR Technique:** A minimally invasive alternative (Puncture, Aspiration, Injection of scolicidal, Re-aspiration). * **Water-lily sign:** A classic radiological finding on MRI/CT indicating a ruptured endocyst floating in the pericyst.

Question 728: Which statement regarding antibiotic prophylaxis is true?

A. Antibiotic prophylaxis is not indicated for clean-contaminated surgery.
B. Antibiotic prophylaxis is not indicated for gastric ulcer surgery.
C. Antibiotic prophylaxis is indicated for colorectal surgery. (Correct Answer)
D. Local irrigation with antibiotics is contraindicated when systemic antibiotics are given.

Explanation: ### Explanation **1. Why Option C is Correct:** The primary goal of antibiotic prophylaxis is to reduce the incidence of Surgical Site Infections (SSI) by ensuring therapeutic drug levels in the tissue at the time of incision. **Colorectal surgery** is classified as **Clean-Contaminated** (or Contaminated if there is spillage), involving entry into a colonized viscus with a high bacterial load (anaerobes and Gram-negative bacilli). Prophylaxis is mandatory here as it significantly reduces the high baseline risk of infection. **2. Why Other Options are Incorrect:** * **Option A:** Antibiotic prophylaxis **is indicated** for all clean-contaminated surgeries (e.g., cholecystectomy, elective GI surgery) and certain clean surgeries involving implants or prosthetics. * **Option B:** Gastric ulcer surgery is a **Clean-Contaminated** procedure. While the stomach is normally sterile due to acid, conditions like gastric ulcers, malignancy, or use of H2 blockers increase bacterial colonization, making prophylaxis necessary. * **Option D:** Local irrigation with antibiotics is **not contraindicated**; in fact, it is sometimes used as an adjunct in heavily contaminated wounds (e.g., peritonitis), though it does not replace the need for systemic administration. **3. NEET-PG High-Yield Pearls:** * **Timing:** The most crucial factor. Antibiotics must be administered **within 60 minutes before the skin incision** (except Vancomycin/Fluoroquinolones, which require 120 minutes). * **Duration:** A single preoperative dose is usually sufficient. It should **not exceed 24 hours** postoperatively for most procedures. * **Wound Classification & Prophylaxis:** * **Clean:** No prophylaxis (unless implant/prosthesis used). * **Clean-Contaminated:** Prophylaxis indicated. * **Contaminated/Dirty:** Requires **therapeutic** antibiotics (treatment, not just prophylaxis).

Question 729: Hyponatremia in multiple myeloma is:

A. True
B. Relative
C. Absolute
D. Pseudo (Correct Answer)

Explanation: **Explanation:** **Pseudohyponatremia** is the correct answer because Multiple Myeloma is characterized by extreme **hyperproteinemia** (specifically monoclonal paraproteins). In a laboratory setting, serum is composed of water (~93%) and solids like proteins and lipids (~7%). Sodium is restricted to the water phase. When proteins are pathologically elevated (as in Multiple Myeloma), the solid fraction increases, displacing the water fraction. Standard laboratory techniques (like flame photometry or indirect ion-selective electrodes) dilute the total volume, leading to a falsely low sodium reading per unit of total volume, even though the actual sodium concentration in the serum water remains normal. **Analysis of Options:** * **Relative Hyponatremia (B):** This usually refers to dilutional hyponatremia (e.g., SIADH or CHF) where total body water increases relative to sodium. In Myeloma, there is no actual excess of water. * **Absolute Hyponatremia (C):** This implies a true deficit in total body sodium or a true excess of water. In pseudohyponatremia, the measured low sodium is a laboratory artifact, not a physiological state. * **True Hyponatremia (A):** This is incorrect because the serum osmolality in these patients is typically normal (isotonic hyponatremia). **High-Yield Clinical Pearls for NEET-PG:** * **Causes of Pseudohyponatremia:** Hyperproteinemia (Multiple Myeloma, IVIG therapy) and Hyperlipidemia (Chylomicronemia). * **Diagnostic Tip:** To confirm pseudohyponatremia, measure **Serum Osmolality** (it will be normal) or use **Direct Ion-Selective Electrode (Direct ISE)**, which does not require sample dilution and provides the true sodium level. * **Multiple Myeloma Triad:** Anemia, Bone pain (lytic lesions), and Renal insufficiency. Always check for "M-spike" on protein electrophoresis.

Question 730: Gastrojejernostomy surgery belongs to which of the following categories?

A. Clean surgery
B. Contaminated surgery
C. Clean-contaminated surgery (Correct Answer)
D. Dirty surgery

Explanation: ### Explanation The classification of surgical wounds is based on the degree of microbial contamination at the time of surgery, which predicts the risk of postoperative surgical site infection (SSI). **1. Why Clean-Contaminated is Correct:** Gastrojejunostomy involves an elective opening into the gastrointestinal tract (a hollow viscus) under controlled conditions without significant spillage. By definition, **Clean-Contaminated (Class II)** surgeries are those where the respiratory, alimentary, genital, or urinary tracts are entered under controlled conditions and without unusual contamination. Since the stomach and jejunum are part of the alimentary tract, this procedure falls into Class II. **2. Why Other Options are Incorrect:** * **Clean (Class I):** These are uninfected operative wounds in which no inflammation is encountered and the respiratory, alimentary, genital, or urinary tracts are **not** entered (e.g., Hernioplasty, Thyroidectomy). * **Contaminated (Class III):** These involve open, fresh, accidental wounds, or operations with major breaks in sterile technique or gross spillage from the GI tract. It also includes acute, non-purulent inflammation (e.g., inflamed appendectomy). * **Dirty (Class IV):** These involve old traumatic wounds with retained devitalized tissue or those involving existing clinical infection or perforated viscera (e.g., Peritonitis due to perforated peptic ulcer). **3. Clinical Pearls for NEET-PG:** * **SSI Risk:** Clean (<2%), Clean-Contaminated (<10%), Contaminated (15-20%), Dirty (up to 40%). * **Prophylactic Antibiotics:** Usually administered for Class II and III. For Class I, they are only given if a prosthetic implant is used (e.g., Mesh in Hernioplasty). * **Cholecystectomy:** Elective is Clean-Contaminated; if there is acute inflammation or bile spillage, it becomes Contaminated. * **Vagotomy:** If done alone (without drainage like GJ), it is a **Clean** surgery. Once the GI lumen is opened (GJ), it becomes **Clean-Contaminated**.

Practice by Chapter

Wound Healing and Care

Practice Questions

Surgical Infections

Practice Questions

Fluid and Electrolyte Management

Practice Questions

Nutrition in Surgical Patients

Practice Questions

Hemostasis and Blood Transfusion

Practice Questions

Surgical Instruments and Equipment

Practice Questions

Sutures and Stapling Devices

Practice Questions

Minimal Access Surgery Principles

Practice Questions

Surgical Complications

Practice Questions

Anesthesia Principles for Surgeons

Practice Questions

Surgical Oncology Principles

Practice Questions

Evidence-Based Surgery

Practice Questions

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