Complications in Anesthesia Practice Questions

Q: A 45-year-old woman undergoing general anesthesia for cholecystectomy suddenly develops tachycardia (140/min), rising end-tidal CO2 (65 mm Hg), muscle rigidity, and temperature increasing from 98.6°F to 104°F (37°C to 40°C) within 20 minutes. Her father reportedly died during surgery years ago. Apply the appropriate immediate intervention.

Discontinue triggering agents and administer dantrolene. ***Discontinue triggering agents and administer dantrolene*** - The patient is experiencing **Malignant Hyperthermia (MH)**, a hypermetabolic crisis triggered by **volatile anesthetics** or **succinylcholine**, characterized by rising **end-tidal CO2**, tachycardia, and muscle rigidity. - Immediate management requires stopping the trigger and administering **dantrolene**, which acts by inhibiting **calcium release** from the **ryanodine receptor (RYR1)** in the sarcoplasmic reticulum. *Administer broad-spectrum antibiotics* - While fever and tachycardia can suggest sepsis, the rapid onset of **hypercapnia** and **muscle rigidity** under anesthesia is pathognomonic for **Malignant Hyperthermia**. - Antibiotics will not treat the underlying **hypermetabolic state** caused by uncontrolled intracellular calcium levels. *Hyperventilate and administer neuromuscular blockers* - Though hyperventilation with **100% oxygen** is part of supportive care, common neuromuscular blockers like **succinylcholine** can actually trigger or worsen the crisis. - Rigidity in MH is caused by direct calcium-induced contraction at the **myocyte level**, so typical paralytics may be ineffective and do not address the primary pathology. *Apply external cooling and continue anesthesia* - Cooling is a necessary supportive measure, but **continuing anesthesia** with triggering agents is lethal due to the ongoing metabolic storm. - External cooling alone cannot stop the **intracellular calcium surge** that drives the rapid rise in body temperature. *Continue surgery and administer antipyretics* - Antipyretics like acetaminophen work on the **hypothalamic set point** and are ineffective for the **peripheral heat production** seen in MH. - MH is a medical emergency with a high mortality rate; surgery must be **aborted** or transitioned to non-triggering agents (like TIVA) immediately.

Q: Propofol infusion syndrome is characterized by

Bradycardia. **Explanation:** **Propofol Infusion Syndrome (PRIS)** is a rare but potentially fatal complication associated with high-dose (>4 mg/kg/hr) and long-term (>48 hours) infusions of propofol. **Why Bradycardia is Correct:** The pathophysiology of PRIS involves the inhibition of mitochondrial oxidative phosphorylation and fatty acid oxidation. This creates a severe energy deficit in cardiac and skeletal muscles. The hallmark cardiac manifestation is **refractory bradycardia**, which often progresses to asystole. This bradycardia is typically preceded by ECG changes such as right bundle branch block and Brugada-like ST-segment elevation in the precordial leads (V1-V3). **Analysis of Incorrect Options:** * **A. Hypokalemia:** Incorrect. PRIS is characterized by **Hyperkalemia**. This occurs due to extensive rhabdomyolysis (muscle breakdown) resulting from the metabolic failure of myocytes. * **B. Hypolipidemia:** Incorrect. PRIS causes **Hypertriglyceridemia**. Since propofol is delivered in a lipid emulsion, and PRIS impairs lipid metabolism, serum triglyceride levels rise significantly. * **D. Tachycardia:** Incorrect. While early stress responses might show transient tachycardia, the diagnostic feature and terminal event of PRIS is progressive, treatment-resistant bradycardia. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Pentad of PRIS:** Cardiomyopathy (Bradycardia/Heart Failure), Metabolic Acidosis (Anion gap), Rhabdomyolysis, Hyperkalemia, and Renal Failure. * **Risk Factors:** High doses, prolonged duration, critical illness, concomitant use of glucocorticoids or catecholamines, and low carbohydrate intake. * **Management:** Immediate cessation of propofol infusion and supportive care (hemodialysis for hyperkalemia/acidosis and pacing for bradycardia).

Q: A 'Mill Wheel Murmur' is heard in which of the following conditions?

Air embolism. **Explanation:** The **Mill Wheel Murmur** is a pathognomonic clinical sign of a **Venous Air Embolism (VAE)**. It is a loud, splashing, churning sound heard over the precordium, caused by the mixing of air and blood within the right ventricle. This "gas lock" obstructs the outflow of blood from the right ventricle into the pulmonary artery, leading to acute right heart failure and cardiovascular collapse. **Why the other options are incorrect:** * **Aortic Dissection:** Typically presents with a tearing chest pain radiating to the back. If a murmur is present, it is usually the diastolic murmur of **aortic regurgitation** (if the dissection involves the aortic root). * **Coarctation of Aorta:** Characterized by a systolic murmur heard best over the **left infraclavicular area and the back** (interscapular), often associated with radio-femoral delay. * **Abdominal Aortic Aneurysm (AAA):** Usually presents as a pulsatile abdominal mass. If a sound is heard, it is an **abdominal bruit**, not a precordial murmur. **High-Yield Clinical Pearls for NEET-PG:** * **Most Sensitive Monitor for VAE:** Transesophageal Echocardiography (TEE). * **Most Sensitive Non-Invasive Monitor:** Precordial Doppler (placed at the 2nd–6th intercostal space, right of the sternum). * **Early Sign:** Decrease in End-Tidal CO2 (ETCO2) due to increased dead space. * **Management:** Place the patient in **Durant’s Position** (Left lateral decubitus and Trendelenburg) to trap air in the apex of the right ventricle, away from the pulmonary outflow tract. Aspirate air via a Central Venous Catheter.

Q: A surgical resident has accidentally administered an intra-arterial injection of thiopental sodium to a patient. The arm has blanched below the level of the injection. Which of the following is NOT recommended for the management?

Immediately remove the needle and apply a warm towel. **Explanation:** Accidental intra-arterial injection of Thiopental sodium (an alkaline solution with pH 10.5) is a medical emergency. It causes immediate **intense pain, vasospasm, and crystal formation**, leading to thrombosis and distal limb ischemia (blanching). **Why Option A is the Correct Answer (The "NOT" recommended action):** The most critical rule in managing intra-arterial injection is **NOT to remove the needle immediately**. The needle should be left in situ to serve as a portal for administering emergency vasodilators (like 1% Procaine, Lidocaine, or Papaverine) directly into the affected artery to counteract vasospasm and dilute the drug. **Analysis of Incorrect Options (Recommended Managements):** * **Option B (Brachial Plexus Block):** This is recommended as it produces sympathetic blockade, leading to vasodilation and improved collateral circulation, while also providing pain relief. * **Option C (IV Heparin):** Systemic anticoagulation is essential to prevent the progression of thrombosis caused by the endarteritis and crystal deposition. * **Option D (Analgesics):** Severe pain triggers further sympathetic-mediated vasoconstriction; therefore, aggressive pain management is a standard part of the protocol. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism of Injury:** Thiopental crystals precipitate in the blood (due to pH change), causing mechanical obstruction and a chemical endarteritis. * **First Step:** Leave the needle in place. * **Drug of Choice for Vasodilation:** **Papaverine** or **1% Procaine** (Procaine is also an acid, which helps neutralize the alkaline Thiopental). * **Other Treatments:** Stellat ganglion block, Phenoxybenzamine, and elevating the limb (to improve venous drainage).

Q: Which position is best for patients with suspected air embolism?

Left Lateral Decubitus with Trendelenburg. **Explanation:** The correct position for managing a suspected venous air embolism (VAE) is the **Left Lateral Decubitus with Trendelenburg position**, also known as the **Durant’s Maneuver**. **1. Why it is correct:** When air enters the venous circulation, it travels to the right atrium and then the right ventricle. In the right ventricle, air can form an "air lock" in the pulmonary outflow tract, obstructing blood flow to the lungs and causing cardiovascular collapse. * **Left Lateral Decubitus:** By placing the patient on their left side, the right ventricular outflow tract (RVOT) is positioned inferior to the right ventricular body. This causes the air bubble to float upward, away from the RVOT, and remain trapped in the apex of the right ventricle. * **Trendelenburg (Head-down):** This further helps in trapping the air in the apex and increases venous pressure, preventing further air entry if the source is above the heart level. **2. Why other options are incorrect:** * **Supine:** In this position, air can easily move from the right atrium into the RVOT, increasing the risk of a fatal air lock. * **Left Lateral:** While helpful, it is incomplete without the Trendelenburg tilt, which provides the gravitational advantage needed to keep air away from the pulmonary artery. * **Trendelenburg:** Alone, this does not prevent the air from migrating into the pulmonary circulation as effectively as when combined with the left lateral tilt. **3. Clinical Pearls for NEET-PG:** * **Most sensitive monitor:** Transesophageal Echocardiography (TEE). * **Most sensitive non-invasive monitor:** Precordial Doppler (placed at the 3rd–6th intercostal space, right sternal border). * **Classic Sign:** "Mill-wheel murmur" (a late sign heard via esophageal stethoscope). * **Immediate Management:** 100% Oxygen, Durant's maneuver, and aspiration of air via a Central Venous Catheter (if present).

Q: Post-anesthetic muscle soreness is most commonly caused by which of the following medications?

Suxamethonium. **Explanation:** **Suxamethonium (Succinylcholine)** is the correct answer. It is a depolarizing neuromuscular blocker that works by mimicking acetylcholine at the motor endplate. Upon administration, it causes a characteristic disorganized contraction of muscle fibers known as **fasciculations**. These intense, unsynchronized contractions lead to micro-trauma of the muscle fibers and the release of lactic acid, resulting in **post-operative myalgia (muscle soreness)**. This is most commonly seen in the neck, shoulders, and abdominal muscles, particularly in young adults undergoing ambulatory surgery. **Analysis of Incorrect Options:** * **Gallamine & D-tubocurarine (d-TC):** These are non-depolarizing neuromuscular blockers (NDMRs). They act as competitive antagonists at the nicotinic receptors and do not cause depolarization or fasciculations; therefore, they do not cause muscle soreness. In fact, a small "pre-curarizing" dose of an NDMR is often used to *prevent* suxamethonium-induced soreness. * **Dantrolene:** This is a muscle relaxant that acts directly on the Ryanodine receptor (RyR1) to inhibit calcium release from the sarcoplasmic reticulum. It is the drug of choice for treating Malignant Hyperthermia and actually reduces muscle contraction rather than causing soreness. **Clinical Pearls for NEET-PG:** * **Incidence:** Muscle soreness is more common in females and "early-ambulated" patients (outpatient procedures). * **Prevention:** Pre-treatment with a small dose of non-depolarizing relaxant (e.g., Vecuronium or d-TC) or NSAIDs can reduce the severity of myalgia. * **Biochemical marker:** Post-suxamethonium soreness is often associated with a transient rise in serum **creatine phosphokinase (CPK)** and myoglobinuria.

Q: A patient undergoing eye surgery received propofol for intravenous anesthesia and succinylcholine as a muscle relaxant. Recovery from anesthesia was uneventful. However, 8 hours post-surgery, the patient complained of leg pain upon walking. What is the most likely cause of this symptom?

Succinylcholine. ### Explanation The correct answer is **Succinylcholine**. **Why Succinylcholine is the cause:** The patient is experiencing **postoperative myalgia (POM)**, a well-known side effect of Succinylcholine (Suxamethonium). Succinylcholine is a depolarizing neuromuscular blocker that acts by mimicking acetylcholine at the motor endplate. This causes disorganized muscle contractions known as **fasciculations** before paralysis occurs. These fasciculations lead to microscopic muscle fiber damage and the release of prostaglandins and lactic acid, resulting in muscle pain. * **Timing:** Typically occurs 12–24 hours post-surgery (though can start sooner). * **Location:** Most common in the neck, shoulders, and abdominal muscles, but often felt in the legs upon mobilization. * **Risk Factors:** Young adults, females, and patients undergoing minor/ambulatory surgery (early mobilization exacerbates the pain). **Why other options are incorrect:** * **Propofol:** While propofol can cause pain on injection, it does not cause delayed systemic muscle pain. * **Post-surgical pain:** Pain from eye surgery (ophthalmic) would be localized to the periorbital area, not the legs. * **Early mobilization:** While walking triggers the sensation of myalgia, it is the *inciting agent* (Succinylcholine) that is the underlying cause. **High-Yield Clinical Pearls for NEET-PG:** * **Prevention:** Pre-treatment with a small dose of a **non-depolarizing muscle relaxant (NDMR)** (e.g., Vecuronium or Rocuronium) can reduce the severity of fasciculations and subsequent myalgia. * **Contraindications:** Avoid Succinylcholine in patients with burns, massive trauma, or upper motor neuron lesions due to the risk of **hyperkalemia**. * **Association:** Succinylcholine is a potent trigger for **Malignant Hyperthermia**.

Q: What is true about post-spinal headache?

Low incidence with thin (25 G) needles. **Post-Dural Puncture Headache (PDPH)** is a common complication following spinal anesthesia, caused by the persistent leakage of cerebrospinal fluid (CSF) through the dural hole. This leads to low CSF pressure and compensatory cerebral vasodilation. ### **Explanation of Options** * **Correct Option (C):** The incidence of PDPH is directly proportional to the diameter of the needle used. Using **thinner needles (e.g., 25 G, 27 G)** or non-cutting (pencil-point) needles like **Whitacre or Sprotte** significantly reduces the size of the dural rent, thereby lowering the incidence of headache. * **Option A:** PDPH is typically **occipital or frontal**, but it characteristically radiates to the neck and shoulders. * **Option B:** A hallmark of PDPH is its **orthostatic nature**. It is worsened by sitting or standing and is characteristically **relieved by lying flat**. * **Option D:** Abdominal compression (or the Girdle test) actually **decreases** the severity of the headache. It increases intra-abdominal pressure, which is transmitted to the epidural space, thereby reducing CSF leakage and increasing intracranial pressure. ### **High-Yield Clinical Pearls for NEET-PG** * **Gold Standard Treatment:** **Epidural Blood Patch** (15–20 ml of autologous blood injected into the epidural space). * **Needle Type:** Pencil-point needles (Whitacre/Sprotte) have a lower incidence of PDPH compared to cutting-tip needles (Quincke) because they separate rather than cut dural fibers. * **Risk Factors:** Young age, female gender, pregnancy, and a history of previous PDPH. * **Conservative Management:** Bed rest, aggressive hydration, oral/IV caffeine (causes cerebral vasoconstriction), and analgesics.

Question 1

A 45-year-old woman undergoing general anesthesia for cholecystectomy suddenly develops tachycardia (140/min), rising end-tidal CO2 (65 mm Hg), muscle rigidity, and temperature increasing from 98.6°F to 104°F (37°C to 40°C) within 20 minutes. Her father reportedly died during surgery years ago. Apply the appropriate immediate intervention.

Accepted Answer

Discontinue triggering agents and administer dantrolene

Answer

Administer broad-spectrum antibiotics

Answer

Hyperventilate and administer neuromuscular blockers

Answer

Apply external cooling and continue anesthesia

Answer

Continue surgery and administer antipyretics

Question 2

Propofol infusion syndrome is characterized by

Accepted Answer

Bradycardia

Answer

Hypokalemia

Answer

Hypolipidemia

Answer

Tachycardia

Question 3

A 'Mill Wheel Murmur' is heard in which of the following conditions?

Accepted Answer

Air embolism

Answer

Aortic dissection

Answer

Coarctation of aorta

Answer

Abdominal aortic aneurysm

Question 4

A surgical resident has accidentally administered an intra-arterial injection of thiopental sodium to a patient. The arm has blanched below the level of the injection. Which of the following is NOT recommended for the management?

Accepted Answer

Immediately remove the needle and apply a warm towel

Answer

Perform a brachial plexus block on the affected side

Answer

Administer IV heparin

Answer

Administer analgesics

Question 5

With respect to cardiac arrests occurring during anesthesia, which of the following statements are correct?

Accepted Answer

The most common preceding arrhythmia is bradycardia and the most common cause is failure of ventilation.

Answer

The most common preceding arrhythmia is bradycardia and most occur during emergence from anesthesia.

Answer

The most common preceding arrhythmia is bradycardia.

Answer

The most common preceding arrhythmia is bradycardia and most are considered unpreventable and untreatable.

Question 6

Which position is best for patients with suspected air embolism?

Accepted Answer

Left Lateral Decubitus with Trendelenburg

Answer

Supine

Answer

Left Lateral

Answer

Trendelenburg

Question 7

Post-anesthetic muscle soreness is most commonly caused by which of the following medications?

Accepted Answer

Suxamethonium

Answer

Gallamine

Answer

D-tubocurarine (d-TC)

Answer

Dantrolene

Question 8

A patient undergoing eye surgery received propofol for intravenous anesthesia and succinylcholine as a muscle relaxant. Recovery from anesthesia was uneventful. However, 8 hours post-surgery, the patient complained of leg pain upon walking. What is the most likely cause of this symptom?

Accepted Answer

Succinylcholine

Answer

Propofol

Answer

Post-surgical pain

Answer

Early mobilization

Question 9

While inserting a central venous catheter, a patient develops respiratory distress. Which of the following is the most likely cause?

Accepted Answer

Pneumothorax

Answer

Hemothorax

Answer

Hypovolemia

Answer

Pleural effusion

Question 10

What is true about post-spinal headache?

Accepted Answer

Low incidence with thin (25 G) needles

Answer

Frontal location

Answer

Worse when lying down

Answer

Increased by abdominal compression

Complications in Anesthesia — MCQs

Complications in Anesthesia — MCQs

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