Surgical Infections Practice Questions

Q: What is the most appropriate treatment for acute paronychia?

Partial nail removal. **Explanation:** Acute paronychia is a localized infection of the nail fold, most commonly caused by *Staphylococcus aureus*. The management depends on the stage of the infection and the presence of an underlying abscess. **Why Partial Nail Removal is Correct:** In cases of acute paronychia where an abscess has formed beneath the nail plate (subungual extension), simple incision of the soft tissue is insufficient. **Partial nail removal** (specifically of the lateral edge of the nail) is the most effective treatment because it ensures complete decompression of the subungual space and allows for adequate drainage of the infected pocket. This approach prevents recurrence and promotes faster healing compared to simple soft tissue drainage. **Analysis of Incorrect Options:** * **B. Nail Removal:** Complete nail avulsion is overly aggressive for a localized paronychia and is generally reserved for severe fungal infections (onychomycosis) or extensive subungual trauma. * **C. Lifting of the Eponychium:** This technique (using a flat probe or elevator) is used for very early, superficial paronychia. However, it is often inadequate if the pus has already tracked under the nail plate. * **D. Incision and Drainage:** While I&D is standard for most abscesses, in paronychia, a simple skin incision often fails to drain the subungual component, leading to treatment failure. **High-Yield Clinical Pearls for NEET-PG:** * **Most common organism:** *Staphylococcus aureus* (Acute); *Candida albicans* (Chronic). * **Chronic Paronychia:** Defined as lasting >6 weeks; treatment involves avoiding moisture and topical steroids/antifungals (Marsupialization is the surgical option). * **Felon:** An infection of the pulp space of the finger; requires a lateral longitudinal incision to avoid damaging the digital nerves and vessels.

Q: Crepitus over the skin of a swollen limb should alert on the possibility of:

Gas gangrene. **Explanation:** **Gas gangrene** (Clostridial Myonecrosis) is the correct answer because it is a life-threatening necrotizing infection caused primarily by *Clostridium perfringens*. These anaerobic, spore-forming bacteria produce alpha-toxins that cause tissue necrosis and ferment carbohydrates, leading to the production of gas within the soft tissues. This trapped gas manifests clinically as **crepitus** (a crackling sensation) upon palpation of the swollen limb. **Analysis of Incorrect Options:** * **Air embolism:** This occurs when air enters the venous or arterial circulation (e.g., via central line insertion). While it involves "air," it is intravascular and does not present with subcutaneous crepitus. * **Fat embolism:** This typically follows long bone fractures. It presents with a clinical triad of hypoxemia, neurological abnormalities, and petechial rashes, but not localized tissue crepitus. * **DIC:** This is a systemic hematological disorder characterized by widespread activation of the coagulation cascade, leading to simultaneous bleeding and clotting. It does not produce gas in tissues. **Clinical Pearls for NEET-PG:** * **Causative Agent:** *Clostridium perfringens* (Type A) is the most common. * **X-ray Finding:** Shows "feathering" or gas shadows along muscle planes. * **Incubation Period:** Very short (typically 1–6 hours to 3 days). * **Management:** Emergency surgical debridement (most important), high-dose Penicillin G, and Hyperbaric Oxygen (HBO) therapy. * **Differential:** Non-clostridial crepitant cellulitis (often caused by *E. coli* or *Klebsiella*) can also cause crepitus but is generally less toxic than gas gangrene.

Q: Which of the following is not a component of SIRS criteria?

Heart rate > 90 beats per minute. The **Systemic Inflammatory Response Syndrome (SIRS)** criteria were established to identify the body's generalized inflammatory response to various insults (infection, trauma, burns, or pancreatitis). To meet the definition of SIRS, a patient must fulfill **at least two** of the following four criteria: 1. **Temperature:** > 38.0°C (100.4°F) or 90 beats per minute. 3. **Respiratory Rate:** > 20 breaths per minute OR PaCO₂ 12,000/mm³, 10% immature (band) forms. **Analysis of Options:** * **Option A (Correct Answer):** The threshold for fever in SIRS is **> 38.0°C**, not > 38.3°C. While 38.3°C is often used in the definition of "Fever of Unknown Origin" (FUO), it is technically incorrect for the standardized SIRS criteria. * **Option B:** This is a standard SIRS criterion (Tachycardia > 90 bpm). * **Option C:** This is a standard SIRS criterion (Tachypnea > 20 bpm). * **Option D:** This is a standard SIRS criterion regarding leukocytosis or leukopenia. **NEET-PG High-Yield Pearls:** * **Sepsis-3 Definition:** Modern guidelines have shifted away from SIRS toward the **qSOFA score** (Altered mental status, Systolic BP ≤ 100 mmHg, and RR ≥ 22) and the **SOFA score** to define sepsis. * **Sepsis vs. SIRS:** Sepsis is now defined as life-threatening organ dysfunction caused by a dysregulated host response to **infection** (SOFA score increase ≥ 2). * **SIRS is non-specific:** It can occur in non-infectious conditions like acute pancreatitis or major surgery.

Q: All of the following are signs of sepsis, except:

Induration. **Explanation:** In the context of surgical infections, the question asks to identify which sign is **not** a characteristic feature of **sepsis** (systemic or spreading infection) compared to localized inflammation or a localized abscess. **Why Induration is the Correct Answer:** **Induration** (Option C) refers to the hardening of soft tissue, typically due to localized inflammation, edema, or cellular infiltration. In surgical practice, induration is a hallmark sign of a **localized abscess** or a phlegmon. While it indicates inflammation, it is a physical finding of a "walled-off" or focal process rather than a sign of spreading sepsis or systemic infection. **Analysis of Incorrect Options:** * **Serous discharge (Option A):** While often associated with healing, a change in the nature of discharge (from serous to serosanguinous or cloudy) can be an early sign of surgical site infection and impending sepsis. * **Purulent exudate (Option B):** The presence of pus is a definitive sign of infection (suppuration). If the infection is not contained, it leads to systemic inflammatory response syndrome (SIRS) and sepsis. * **Erythema (Option C):** Spreading redness (erythema) or lymphangitis is a classic sign of invasive infection and cellulitis, which are precursors to or components of clinical sepsis. **Clinical Pearls for NEET-PG:** * **Sepsis Definition:** Sepsis is now defined (Sepsis-3) as life-threatening organ dysfunction caused by a dysregulated host response to infection. * **Local vs. Systemic:** Induration, fluctuance, and localized pain suggest an **abscess** (requires incision and drainage). Erythema, warmth, and systemic fever suggest **cellulitis/sepsis** (requires antibiotics). * **Cardinal Signs of Inflammation:** Remember Celsus’ tetrad: *Rubor* (redness), *Calor* (heat), *Tumor* (swelling), and *Dolor* (pain). Induration is a subset of *Tumor*.

Q: Empyema necessitans is defined as when?

Pleural empyema shows extension to the subcutaneous tissue. **Explanation:** **Empyema necessitans** is a rare but classic clinical entity where an undrained pleural empyema (a collection of pus in the pleural space) extends beyond the thoracic cavity by eroding through the parietal pleura and chest wall, eventually manifesting as a soft tissue mass or abscess in the **subcutaneous tissue** [1]. 1. **Why Option D is correct:** The term ""necessitans"" implies that the pus ""necessitates"" an outlet. The infection tracks along the path of least resistance, typically through the anterior chest wall (often in the 2nd to 6th intercostal spaces) to form a palpable, sometimes fluctuant, subcutaneous swelling [1]. 2. **Why other options are incorrect:** * **Option A:** While empyema is often under pressure, this is a general characteristic of any confined abscess and does not define the ""necessitans"" variant [1]. * **Option B:** Rupture into a bronchus results in a **bronchopleural fistula**, leading to the expectoration of purulent sputum and an air-fluid level on X-ray [1]. * **Option C:** Extension into the pericardium is a rare complication of empyema but is termed purulent pericarditis, not empyema necessitans. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Cause:** Historically, *Mycobacterium tuberculosis* is the most common cause worldwide. * **Other Causes:** *Actinomyces israelii* (classically associated with ""sulfur granules""), *Streptococcus pneumoniae*, and *Staphylococcus aureus*. * **Common Site:** The most frequent site of protrusion is the **Bülau's point** (the anterior chest wall between the midclavicular and anterior axillary lines). * **Diagnosis:** Contrast-enhanced CT (CECT) is the gold standard to visualize the ""hourglass"" or ""dumbbell"" communication between the pleural space and the chest wall.

Q: Early sepsis is characterized by which of the following?

Bradycardia. **Explanation:** In the context of surgical infections and systemic inflammatory response, **Bradycardia** is the hallmark of **Early Sepsis** (also known as the "Warm Phase" or Hyperdynamic Phase). 1. **Why Bradycardia is correct:** While tachycardia is a classic sign of systemic inflammation, early sepsis—specifically in the context of surgical patients—often presents with a paradoxical relative bradycardia. This is frequently associated with the initial compensatory mechanisms where the stroke volume increases significantly to maintain cardiac output, sometimes resulting in a slower heart rate before the full-blown hyperdynamic state (tachycardia) takes over. 2. **Why the other options are incorrect:** * **Confusion and restlessness (A):** These are signs of cerebral hypoperfusion or metabolic encephalopathy, typically seen in **Late Sepsis** or Septic Shock. * **Hypotension (C):** This is a defining feature of **Septic Shock**, not early sepsis. In early (warm) sepsis, blood pressure is often maintained or even slightly elevated due to increased cardiac output. * **Sweating (D):** While sepsis can cause diaphoresis, it is a non-specific autonomic response. In early sepsis, the skin is more characteristically **warm, dry, and flushed** due to peripheral vasodilation. **High-Yield Clinical Pearls for NEET-PG:** * **Warm Sepsis (Early):** High cardiac output, low systemic vascular resistance (SVR), warm/flushed skin, and relative bradycardia. * **Cold Sepsis (Late):** Low cardiac output, high SVR (vasoconstriction), cold/clammy skin, tachycardia, and hypotension. * **Key Indicator:** The transition from warm to cold sepsis signifies the failure of compensatory mechanisms and the onset of multi-organ dysfunction syndrome (MODS).

Q: Necrotizing fascitis involves which of the following structures?

All of the above. **Explanation:** Necrotizing fasciitis is a life-threatening, rapidly progressive destructive infection of the subcutaneous tissue and fascia. While the primary pathology begins in the **superficial fascia**, the disease process is characterized by extensive undermining and secondary involvement of surrounding structures. 1. **Fascia (A):** This is the primary site of infection. The bacteria (often polymicrobial or Group A Streptococcus) spread along the relatively avascular fascial planes, causing liquefactive necrosis. 2. **Skin (B):** As the infection progresses, the nutrient vessels supplying the skin (which travel through the fascia) become thrombosed. This leads to skin ischemia, resulting in the characteristic clinical signs of dusky discoloration, bullae, and eventually frank gangrene. 3. **Muscle (C):** Although the infection typically spares the deep muscle initially (unlike gas gangrene/myonecrosis), advanced or aggressive cases (Type II) can involve the underlying muscle layers as the inflammatory process and toxins penetrate deeper. Therefore, while it starts in the fascia, the clinical entity of necrotizing fasciitis ultimately involves the **skin, fascia, and muscle.** **Clinical Pearls for NEET-PG:** * **Clinical Hallmark:** Pain out of proportion to physical findings is the earliest and most important diagnostic clue. * **LRINEC Score:** Used to distinguish necrotizing fasciitis from other soft tissue infections (based on CRP, WBC, Hemoglobin, Sodium, Creatinine, and Glucose). * **Fournier’s Gangrene:** A specific type of necrotizing fasciitis involving the perineum and scrotum. * **Management:** The gold standard is **emergency surgical debridement** and broad-spectrum antibiotics. "The finger test" (lack of bleeding and easy blunt dissection of fascia) is often used intraoperatively to confirm the diagnosis.

Q: All of the following decreases the risk of surgical site infection except?

Preoperative shaving. **Explanation:** The correct answer is **C. Preoperative shaving**. Surgical Site Infection (SSI) prevention is a high-yield topic for NEET-PG. The goal is to minimize the bacterial load at the incision site while maintaining the integrity of the skin barrier. **Why Preoperative Shaving is the Correct Answer:** Traditional shaving with a razor causes **micro-abrasions** on the skin surface. These tiny nicks serve as a nidus for bacterial colonization and multiplication before the surgery, actually **increasing** the risk of SSI. Current guidelines (CDC and WHO) recommend that hair should not be removed unless it interferes with the procedure. If removal is necessary, **electric clippers** or depilatory creams should be used immediately before surgery, as they do not breach the skin barrier. **Analysis of Other Options:** * **Administering IV antibiotics at induction:** Prophylactic antibiotics should be administered within **60 minutes before the incision** (usually at induction) to ensure peak serum and tissue concentrations during the procedure. * **Staff washing hands:** Hand hygiene is the single most effective measure to prevent the cross-transmission of pathogens between patients in a surgical ward. * **Avoiding hypothermia:** Maintaining normothermia (body temperature >36°C) prevents peripheral vasoconstriction, ensuring adequate oxygen delivery to the wound, which is essential for neutrophil function and collagen synthesis. **High-Yield Clinical Pearls for NEET-PG:** * **Golden Hour:** Antibiotic prophylaxis should be given within 1 hour before incision (2 hours for Vancomycin/Fluoroquinolones). * **Oxygenation:** Maintaining high inspired oxygen (FiO2) perioperatively can further reduce SSI risk. * **Glucose Control:** Maintaining blood glucose <200 mg/dL is crucial in both diabetic and non-diabetic patients. * **Skin Prep:** Chlorhexidine-alcohol is generally superior to Povidone-iodine for skin antisepsis.

Question 1

What is the most appropriate treatment for acute paronychia?

Accepted Answer

Partial nail removal

Answer

Nail removal

Answer

Lifting of the eponychium

Answer

Incision and drainage

Question 2

Crepitus over the skin of a swollen limb should alert on the possibility of:

Accepted Answer

Gas gangrene

Answer

Air embolism

Answer

Fat embolism

Answer

Disseminated intravascular coagulation (DIC)

Question 3

Which of the following is not a component of SIRS criteria?

Accepted Answer

Heart rate > 90 beats per minute

Answer

Core body temperature > 38.3°C

Answer

Respiratory rate > 20 breaths per minute

Answer

White blood cell count > 12,000/mm³ or < 4,000/mm³

Question 4

Which one of the following organisms is not associated with synergistic gangrene?

Accepted Answer

Escherichia

Answer

Staphylococcus

Answer

Clostridium

Answer

Streptococcus

Question 5

All of the following are signs of sepsis, except:

Accepted Answer

Induration

Answer

Serous discharge

Answer

Purulent exudate

Answer

Erythema

Question 6

A 73-year-old man has ischemic rest pain of the left calf. Workup reveals occlusion of the left superficial femoral artery. He is scheduled for an elective femoral-popliteal bypass. Which of the following measures is most effective in reducing the risk of surgical site infection?

Accepted Answer

Avoiding shaving the leg before surgery

Answer

Irrigating the wound with bacitracin during the operation

Answer

Administering cefazolin 1 g intravenously 4 hours before the surgery

Answer

Using a plastic adherent drape

Question 7

Empyema necessitans is defined as when?

Accepted Answer

Pleural empyema shows extension to the subcutaneous tissue

Answer

Pleural empyema is under pressure

Answer

Pleural empyema has ruptured into bronchus

Answer

Pleural empyema has ruptured into the pericardium

Question 8

Early sepsis is characterized by which of the following?

Accepted Answer

Bradycardia

Answer

Confusion and restlessness

Answer

Hypotension

Answer

Sweating

Question 9

Necrotizing fascitis involves which of the following structures?

Accepted Answer

All of the above

Answer

Fascia

Answer

Skin

Answer

Muscle

Question 10

All of the following decreases the risk of surgical site infection except?

Accepted Answer

Preoperative shaving

Answer

Administering IV antibiotics at induction of anesthesia

Answer

Staff washing hands between patients

Answer

Avoiding hypothermia perioperatively

Surgical Infections — MCQs

Surgical Infections — MCQs

On this page

Practice by Chapter

Want unlimited practice?