Complications in Anesthesia Practice Questions

Q: Which of the following is NOT true about malignant hyperthermia?

Bradycardia is a common occurrence.. **Malignant Hyperthermia (MH)** is a life-threatening pharmacogenetic hypermetabolic disorder of skeletal muscle, primarily triggered by volatile anesthetics and succinylcholine. ### **Explanation of Options** * **D. Bradycardia is a common occurrence (Correct Answer):** This statement is **false**. In MH, the hypermetabolic state leads to sympathetic overactivity. **Tachycardia** is actually the earliest and most consistent clinical sign. Bradycardia only occurs as a terminal event due to severe hyperkalemia or myocardial failure. * **A. Succinylcholine is the most common precipitating agent:** This is true. Succinylcholine (a depolarizing muscle relaxant) and volatile inhalational anesthetics (like Halothane, Isoflurane, and Sevoflurane) are the primary triggers that cause uncontrolled calcium release from the sarcoplasmic reticulum. * **B. Dantrolene is the treatment of choice:** This is true. Dantrolene is a postsynaptic muscle relaxant that binds to the **Ryanodine Receptor (RYR1)**, inhibiting the release of calcium. It is the gold-standard treatment. * **C. End-tidal carbon dioxide (EtCO2) is increased:** This is true. An unexplained, rapid rise in EtCO2 (despite increasing minute ventilation) is often the **first sign** of MH, reflecting the massive increase in metabolic rate and CO2 production. ### **High-Yield Clinical Pearls for NEET-PG** * **Inheritance:** Autosomal Dominant; most commonly associated with a mutation in the **RYR1 gene**. * **Early Signs:** Tachycardia, tachypnea, and **Masseter Muscle Rigidity (MMR)** following succinylcholine administration. * **Late Signs:** Hyperthermia (can rise 1°C every 5 minutes), rhabdomyolysis, and cola-colored urine (myoglobinuria). * **Safe Agents:** Nitrous oxide, Propofol, Etomidate, Thiopental, and all local anesthetics. * **Gold Standard Diagnosis:** Caffeine-Halothane Contracture Test (CHCT) on a muscle biopsy.

Q: What is the most common anesthetic complication occurring within the first 24 hours after surgery under general anesthesia?

Atelectasis. **Explanation:** **Atelectasis** is the most common postoperative pulmonary complication (PPC) following general anesthesia, typically occurring within the first 24–48 hours. **Why Atelectasis is the Correct Answer:** During general anesthesia, several factors contribute to the collapse of alveoli: 1. **Reduced Functional Residual Capacity (FRC):** Induction of anesthesia and the use of muscle relaxants cause the diaphragm to shift cephalad, reducing FRC by approximately 20%. 2. **Compression Atelectasis:** The weight of the heart and abdominal contents compresses dependent lung regions. 3. **Absorption Atelectasis:** High concentrations of inspired oxygen ($FiO_2$) wash out nitrogen (the "structural gas" of the alveoli), leading to rapid alveolar collapse. 4. **Mucociliary Dysfunction:** Anesthetic agents impair the clearance of secretions, leading to small airway obstruction. **Analysis of Incorrect Options:** * **Hypertension:** While common in the immediate recovery period due to pain, emergence excitement, or hypercarbia, it is a transient hemodynamic sign rather than a primary systemic complication. * **Renal Failure:** Postoperative acute kidney injury (AKI) is a serious but relatively rare complication, usually associated with major vascular surgery, pre-existing renal disease, or prolonged hypotension. * **Cardiac Arrest:** This is a catastrophic but rare event (incidence approx. 1 in 10,000–20,000 cases), not a "common" complication. **NEET-PG High-Yield Pearls:** * **Most common cause of postoperative fever (Day 1-2):** Atelectasis. * **Prevention:** Preoperative smoking cessation (ideally >8 weeks), incentive spirometry, and early mobilization. * **Recruitment Maneuvers:** Applying positive pressure (e.g., 40 $cmH_2O$ for 40 seconds) intraoperatively can help reopen collapsed alveoli. * **Site of Surgery:** The risk of atelectasis is highest in upper abdominal and thoracic surgeries.

Q: All of the following are true regarding post-spinal headache, EXCEPT?

Associated with photophobia. **Explanation:** Post-Dural Puncture Headache (PDPH) is a common complication following spinal anesthesia or accidental dural puncture during epidural placement. **1. Why Option D is the Correct Answer (The Exception):** While PDPH is characterized by severe headache, it is **not typically associated with photophobia**. Photophobia is a hallmark of meningeal irritation (meningitis) or migraine. If a patient presents with photophobia, fever, and neck stiffness after spinal anesthesia, clinicians should prioritize ruling out **meningitis** rather than assuming PDPH. **2. Analysis of Incorrect Options:** * **Option A (Occurs within 48 hours):** This is true. PDPH typically manifests within 12 to 48 hours post-procedure. It rarely occurs immediately or after 5-7 days. * **Option B (Increased by sitting upright):** This is the **pathognomonic feature** of PDPH. It is a "postural headache" that worsens significantly when the patient sits or stands and is relieved by lying flat (supine). * **Option C (Due to CSF leak):** This is the underlying pathophysiology. Persistent leakage of CSF through the dural hole leads to **low intracranial pressure**. This causes traction on pain-sensitive intracranial structures (vessels and nerves) when the patient is upright. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Young age, female gender, pregnancy, and use of large-bore/cutting needles (e.g., Quincke). * **Prevention:** Use of small-gauge (25G-27G) and **non-cutting (pencil-point)** needles like **Sprotte or Whitacre**. * **Treatment:** Conservative management includes bed rest, hydration, and caffeine. The **Gold Standard** treatment for persistent PDPH is an **Epidural Blood Patch**.

Q: Which intravenous anesthetic agent does not cause histamine release?

Etomidate. **Explanation:** The release of histamine from mast cells is a common side effect of several intravenous anesthetics, leading to clinical signs such as flushing, tachycardia, hypotension, and bronchospasm. **Why Etomidate is the Correct Answer:** **Etomidate** is a carboxylated imidazole derivative known for its remarkable **hemodynamic stability**. It does not trigger histamine release, making it the induction agent of choice for patients with reactive airway disease (asthma) or those with limited cardiac reserve (valvular heart disease, hypovolemia). **Analysis of Incorrect Options:** * **Thiopentone (Option A):** A barbiturate notorious for causing significant histamine release. It is strictly contraindicated in patients with porphyria and should be avoided in asthmatics due to the risk of bronchospasm. * **Propofol (Option B):** While generally safe, propofol can occasionally cause histamine release. Furthermore, its formulation (containing soybean oil and egg lecithin) can trigger allergic reactions in sensitive individuals. * **Ketamine (Option D):** Although ketamine is a bronchodilator (due to sympathomimetic effects), it can occasionally trigger minor histamine release. However, in the context of NEET-PG questions, Etomidate is the classic answer for "no histamine release." **High-Yield Clinical Pearls for NEET-PG:** * **Etomidate Side Effects:** While it lacks histamine release, it is associated with **adrenocortical suppression** (inhibits 11-beta-hydroxylase) and a high incidence of **myoclonus** and postoperative nausea/vomiting (PONV). * **Drug of Choice:** Etomidate is the drug of choice for **cardiac induction** and **trauma** patients due to minimal effect on blood pressure. * **Muscle Relaxants:** Among NMBAs, **Mivacurium** and **Atracurium** are the most common culprits for histamine release; **Vecuronium** and **Rocuronium** do not cause it.

Q: Which statement is false regarding malignant hyperpyrexia?

Low end tidal carbon dioxide is an early sign.. **Explanation:** Malignant Hyperthermia (MH) is a life-threatening pharmacogenetic hypermetabolic disorder of skeletal muscle, triggered by volatile anesthetics and succinylcholine. **Why Option D is the correct answer (False statement):** The hallmark of MH is a massive increase in metabolic rate. Therefore, a **rapid rise in End-Tidal CO₂ (ETCO₂)**—often doubling or tripling—is the **earliest and most sensitive clinical sign**. Low ETCO₂ would be seen in conditions like pulmonary embolism or cardiac arrest, not MH. **Analysis of other options:** * **Option A:** **Dantrolene sodium** is the definitive treatment. It acts by binding to the ryanodine receptor (RYR1), inhibiting the release of calcium from the sarcoplasmic reticulum. * **Option B:** All **volatile inhalational anesthetics** (Halothane, Isoflurane, Sevoflurane, Desflurane) and the depolarizing muscle relaxant **Succinylcholine** are absolute contraindications in MH-susceptible patients. * **Option C:** The clinical triad of MH includes **muscle rigidity** (due to persistent calcium release), **hyperthermia** (a late but classic sign), and **mixed respiratory/metabolic acidosis** (due to excessive CO₂ and lactate production). **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Autosomal Dominant. * **Genetic Mutation:** Most commonly involving the **RYR1 gene** (Ryanodine receptor). * **Earliest Sign:** Unexplained rise in ETCO₂. * **Early Physical Sign:** Masseter muscle rigidity (MMR) following succinylcholine administration. * **Late Signs:** Hyperthermia (can rise 1°C every 5 minutes), rhabdomyolysis, and cola-colored urine (myoglobinuria). * **Safe Agents:** Nitrous oxide, Propofol, Etomidate, Ketamine, and all Local Anesthetics. * **Gold Standard Test:** Caffeine Halothane Contracture Test (CHCT).

Q: What is the most common complication of surgery performed in the lithotomy position?

Damage to lower limb nerves. ### **Explanation** The **lithotomy position** is frequently used for gynecological, urological, and proctological surgeries. It involves placing the patient’s legs in stirrups, which inherently risks pressure-related injuries and nerve stretching. **1. Why "Damage to lower limb nerves" is correct:** Peripheral nerve injury is the most common complication of this position. The **Common Peroneal Nerve** is the most frequently injured nerve due to compression against the lateral support (stirrup) at the neck of the fibula. Other nerves at risk include the **Saphenous nerve** (medial compression), **Femoral nerve** (excessive hip flexion/abduction), and **Sciatic nerve** (stretching due to knee extension and hip flexion). **2. Why the other options are incorrect:** * **Damage to upper limb nerves:** While brachial plexus injuries can occur in any position (especially Trendelenburg), they are not the *most common* complication specific to the lithotomy position. * **Hypotension:** Hypotension is more common when legs are *lowered* from the lithotomy position (due to venous pooling). While in the position, venous return actually increases, which can sometimes cause transient hypertension. * **Distal gangrene:** This is a rare and extreme complication associated with **Compartment Syndrome**. While lithotomy increases intracompartmental pressure, frank gangrene is far less common than nerve injury. ### **High-Yield Clinical Pearls for NEET-PG:** * **Most common nerve injured:** Common Peroneal Nerve (leads to foot drop). * **Compartment Syndrome:** Risk increases if the surgery lasts **>2–4 hours**. * **Physiological Change:** Functional Residual Capacity (FRC) decreases as abdominal contents push against the diaphragm. * **Prevention:** Ensure adequate padding at the fibular head and avoid hip flexion greater than 90 degrees.

Q: Which of the following anesthetic agents can cause hepatitis?

Halothane. **Explanation:** **Halothane** is the correct answer because it is classically associated with **Halothane Hepatitis**, a rare but severe immune-mediated adverse reaction. **Why Halothane?** Halothane undergoes significant hepatic metabolism (up to 20%) by the Cytochrome P450 system. This process produces **trifluoroacetylated (TFA) proteins**. In susceptible individuals, these act as haptens, triggering an immune response that leads to massive hepatic necrosis. There are two types: * **Type I:** Minor, transient elevation of transaminases. * **Type II:** Fulminant hepatic failure (high mortality), typically occurring 2–14 days after repeat exposure. **Analysis of Incorrect Options:** * **Cyclopropane:** An older, flammable gas primarily known for causing "Cyclopropane shock" (hypotension upon discontinuation) and sensitizing the myocardium to catecholamines, but it is not hepatotoxic. * **Isoflurane & Enflurane:** These are newer halogenated ethers. While they also produce TFA-protein adducts, they do so at a much lower rate (Isoflurane <0.2%, Enflurane ~2%) compared to Halothane. Consequently, the risk of hepatitis is extremely negligible. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Multiple exposures to halothane (most important), obesity, female gender, and middle age. * **Metabolism:** Halothane is metabolized to **trifluoroacetic acid**. * **Other Side Effects:** Halothane causes "Halothane Shakes" (shivering), sensitizes the heart to adrenaline (arrhythmias), and is a potent trigger for **Malignant Hyperthermia**. * **Preferred Agent in Liver Disease:** **Atracurium/Cisatracurium** (muscle relaxants) are preferred due to Hoffman elimination. For induction, **Sevoflurane** is safer as it does not produce TFA-protein adducts.

Question 1

Which of the following is NOT true about malignant hyperthermia?

Accepted Answer

Bradycardia is a common occurrence.

Answer

Succinylcholine is the most common precipitating agent.

Answer

Dantrolene is the treatment of choice.

Answer

End-tidal carbon dioxide is increased.

Question 2

What is the most common anesthetic complication occurring within the first 24 hours after surgery under general anesthesia?

Accepted Answer

Atelectasis

Answer

Hypertension

Answer

Renal failure

Answer

Cardiac arrest

Question 3

All of the following are true regarding post-spinal headache, EXCEPT?

Accepted Answer

Associated with photophobia

Answer

Occurs within 48 hours

Answer

Increased by sitting upright

Answer

Due to cerebrospinal fluid (CSF) leak

Question 4

Which intravenous anesthetic agent does not cause histamine release?

Accepted Answer

Etomidate

Answer

Thiopentone

Answer

Propofol

Answer

Ketamine

Question 5

Which statement is false regarding malignant hyperpyrexia?

Accepted Answer

Low end tidal carbon dioxide is an early sign.

Answer

Dantrolene sodium is the drug of choice.

Answer

Isoflurane is an absolute contraindication.

Answer

Characterized by muscle rigidity, hyperthermia, and metabolic acidosis.

Question 6

Which of the following is NOT a risk factor for the development of surgery-associated chronic kidney disease?

Accepted Answer

Spinal anaesthesia

Answer

Older age

Answer

Congestive cardiac failure (CCF)

Answer

Emergency procedures

Question 7

Which of the following is least useful in the treatment of local anesthetic-induced convulsions?

Accepted Answer

Phenytoin sodium

Answer

Thiopentone sodium

Answer

Midazolam

Answer

Propofol

Question 8

Which one of the following drugs does not produce central anticholinergic syndrome?

Accepted Answer

Glycopyrrolate

Answer

Atropine sulphate

Answer

Antihistamines

Answer

Tricyclic antidepressants

Question 9

What is the most common complication of surgery performed in the lithotomy position?

Accepted Answer

Damage to lower limb nerves

Answer

Damage to upper limb nerves

Answer

Hypotension

Answer

Distal gangrene

Question 10

Which of the following anesthetic agents can cause hepatitis?

Accepted Answer

Halothane

Answer

Cyclopropane

Answer

Isoflurane

Answer

Enflurane

Complications in Anesthesia — MCQs

Complications in Anesthesia — MCQs

On this page

Practice by Chapter

Want unlimited practice?