Complications in Anesthesia Practice Questions

Q: Which of the following is NOT a complication of massive blood transfusion?

Hypercalcemia. **Explanation:** Massive blood transfusion (MBT) is defined as the replacement of one total blood volume within 24 hours or 10 units of PRBCs within 24 hours. The correct answer is **Hypercalcemia** because MBT actually causes **Hypocalcemia**. **1. Why Hypercalcemia is the Correct Answer (The Concept):** Stored blood contains **Sodium Citrate** as an anticoagulant. When large volumes are infused rapidly, the citrate binds to the patient’s ionized calcium, forming calcium citrate. This leads to a decrease in serum ionized calcium levels (**Hypocalcemia**). It is a classic complication, especially in patients with impaired liver function who cannot metabolize citrate efficiently. **2. Why the other options are complications:** * **Hyperkalemia (Option A):** During storage, the RBC membrane becomes leaky, causing potassium to move from the intracellular to the extracellular space. Therefore, stored blood has high potassium levels. * **Acidosis (Option C):** Stored blood is acidic due to the accumulation of lactic acid and the presence of Citrate-Phosphate-Dextrose (CPD) preservative. * **Alkalosis (Option B):** While initial infusion causes acidosis, the late metabolic response is **Metabolic Alkalosis**. This occurs because the liver metabolizes the infused citrate into bicarbonate. **Clinical Pearls for NEET-PG:** * **Hypothermia:** The most common complication of MBT (due to cold blood infusion). * **Dilutional Coagulopathy:** MBT leads to a deficiency of platelets and Factors V and VIII. * **TRALI:** Transfusion-Related Acute Lung Injury is the leading cause of transfusion-related mortality. * **Shift to Left:** Stored blood has low 2,3-DPG, shifting the Oxygen Dissociation Curve to the left (increased affinity, decreased release to tissues).

Q: Which of the following is true about malignant hyperthermia?

Hyperkalemia. **Explanation:** **Malignant Hyperthermia (MH)** is a life-threatening pharmacogenetic hypermetabolic disorder of skeletal muscle, triggered by volatile anesthetics (e.g., Halothane, Sevoflurane) and depolarizing muscle relaxants (Succinylcholine). **Why Hyperkalemia is Correct:** The pathophysiology involves a defect in the **Ryanodine receptor (RYR1)**, leading to an uncontrolled release of calcium from the sarcoplasmic reticulum. This causes sustained muscle contraction, leading to massive ATP consumption, rhabdomyolysis (muscle breakdown), and cell death. As muscle cells rupture, intracellular contents—most notably **Potassium**—are released into the bloodstream, resulting in acute **Hyperkalemia**. This is a critical complication as it can lead to fatal cardiac arrhythmias. **Analysis of Incorrect Options:** * **Hypernatremia (A):** Sodium levels are not typically elevated in the acute phase of MH. * **Hypercalcemia (B):** While there is a massive increase in *intracellular* calcium, serum calcium levels often decrease (hypocalcemia) later in the process as it precipitates in damaged tissues. * **Hypothermia (D):** MH is characterized by a rapid, uncontrolled rise in core body temperature (hyperthermia), often increasing at a rate of 1–2°C every five minutes. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest Sign:** Increase in **EtCO₂** (End-tidal Carbon Dioxide) despite increased ventilation. * **Early Clinical Sign:** Masseter muscle rigidity (Trismus) following Succinylcholine administration. * **Drug of Choice:** **Dantrolene** (Mechanism: Inhibits RYR1 receptors to prevent calcium release). * **Safe Agents:** Nitrous oxide, Propofol, Etomidate, and non-depolarizing neuromuscular blockers (e.g., Vecuronium). * **Associated Conditions:** Central Core Disease, King-Denborough Syndrome.

Q: A patient presents with sudden onset of breathlessness after subclavian vein cannulation. On examination, breath sounds are absent while the chest is hyper-resonant on percussion on one side. What is the most likely cause?

Iatrogenic pneumothorax. **Explanation:** The clinical presentation of sudden breathlessness following central venous cannulation, combined with **absent breath sounds** and **hyper-resonance** on percussion, is the classic triad for a **Pneumothorax**. 1. **Why Option A is correct:** Subclavian vein cannulation carries a high risk of pleural injury due to the close anatomical proximity of the lung apex (cupula) to the vein. When the pleura is punctured, air enters the pleural space, causing the lung to collapse. Hyper-resonance occurs because the chest cavity is filled with air instead of solid lung tissue, and breath sounds disappear because air conduction is interrupted. 2. **Why other options are incorrect:** * **Subclavian vein air embolus:** While it causes sudden breathlessness and hypotension, it would present with a characteristic "mill-wheel murmur" on auscultation and clear breath sounds. * **Malposition of cannula:** This usually presents as difficulty in aspirating blood or infusing fluids, but it does not cause acute respiratory distress or hyper-resonance unless associated with a complication like hydrothorax. * **Cardiac arrhythmia:** This may occur if the guidewire irritates the endocardium, but it would present with palpitations or ECG changes, not focal chest percussion findings. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Chest X-ray (PA view) in expiration showing a visceral pleural line. * **Immediate Management:** If tension pneumothorax is suspected clinically, do not wait for an X-ray; perform immediate needle decompression in the 2nd intercostal space (mid-clavicular line) or 5th intercostal space (anterior axillary line). * **Incidence:** The subclavian approach has a higher risk of pneumothorax compared to the internal jugular vein (IJV) approach.

Q: Emergence delirium with ketamine has an increased incidence in all of the following conditions except:

Dose of ketamine less than 1 mg/kg. **Explanation:** Emergence delirium (or emergence reactions) is a well-known side effect of ketamine, characterized by vivid dreams, hallucinations, and postoperative confusion. The incidence of these reactions is significantly influenced by patient demographics and pharmacological factors. **Why Option C is the correct answer:** The incidence of emergence delirium is **dose-dependent**. Higher doses of ketamine (typically **>2 mg/kg IV**) are associated with a higher frequency of reactions. Conversely, using a lower dose (less than 1 mg/kg) or administering ketamine as part of a multi-modal anesthetic regimen actually reduces the risk. Therefore, a dose less than 1 mg/kg is a protective factor, not a risk factor. **Analysis of Incorrect Options (Risk Factors):** * **Age > 15 years:** Emergence delirium is significantly more common in adults than in children. Pediatric patients generally tolerate ketamine better with fewer psychological disturbances. * **Female gender:** Studies have shown that females have a higher predisposition to experiencing vivid dreams and delirium following ketamine administration compared to males. * **History of personality disorders:** Patients with a history of psychiatric illness, high neuroticism scores, or frequent dreaming are at a significantly higher risk for severe emergence reactions. **High-Yield Clinical Pearls for NEET-PG:** * **Prevention:** Benzodiazepines (specifically **Midazolam**) are the most effective agents for preventing ketamine-induced emergence delirium. * **Mechanism:** Ketamine causes "dissociative anesthesia" by antagonizing NMDA receptors and stimulating the limbic system. * **Environment:** Keeping the patient in a quiet, dark recovery area can help minimize the intensity of the reaction.

Q: Which of the following is NOT a risk factor associated with post-operative nausea and vomiting following strabismus surgery?

Age less than 3 years. **Explanation:** Post-operative nausea and vomiting (PONV) is a common complication following pediatric ophthalmic procedures, particularly strabismus surgery, due to the **oculo-emetic reflex**. **Why Option A is the Correct Answer:** While it may seem counterintuitive, the incidence of PONV is actually **lower in children under the age of 3 years**. The risk increases significantly after age 3 and peaks during puberty. In the pediatric population, the risk of PONV is generally considered to be age-dependent, with infants being relatively "protected" compared to older children and adolescents. **Analysis of Incorrect Options:** * **Duration of Anesthesia (Option B):** The risk of PONV increases with the duration of surgery and anesthesia. Procedures lasting longer than 30 minutes are a well-documented independent risk factor. * **History of PONV (Option C):** A personal or family history of PONV is one of the strongest predictors for its occurrence in future procedures, indicating a lower threshold in the vomiting center. * **History of Motion Sickness (Option D):** There is a strong correlation between motion sickness and PONV. Patients susceptible to motion-induced emesis are significantly more likely to experience nausea following anesthesia. **High-Yield Clinical Pearls for NEET-PG:** * **Strabismus Surgery:** This is the surgical procedure with the highest incidence of PONV in children (up to 70% without prophylaxis). * **Oculo-emetic Reflex:** Triggered by traction on extraocular muscles (medial rectus most commonly), leading to bradycardia (oculocardiac reflex) and vomiting. * **Risk Factors (Apfel Score for Adults):** Female gender, non-smoker, history of PONV/motion sickness, and use of postoperative opioids. * **Prevention:** Use of Propofol for induction/maintenance (TIVA), adequate hydration, and prophylactic antiemetics (e.g., Dexamethasone or Ondansetron).

Q: A postpartum lady, 48 hours after a cesarean section, presents with headache and signs of meningism. The headache is relieved upon lying down. What is the immediate treatment?

Epidural blood patch. **Explanation:** The patient is presenting with a classic case of **Post-Dural Puncture Headache (PDPH)**, a common complication following neuraxial anesthesia (spinal or accidental dural puncture during epidural). The hallmark sign is a **postural headache**—worsened by standing/sitting and relieved by lying flat—often accompanied by neck stiffness (meningism), nausea, or photophobia. **Why Option A is Correct:** The **Epidural Blood Patch (EBP)** is the **gold standard and definitive treatment** for PDPH. It involves injecting 15–20 ml of autologous venous blood into the epidural space near the site of the dural puncture. The blood clots, "patching" the dural hole to stop further Cerebrospinal Fluid (CSF) leakage and increasing the pressure in the epidural space, which restores intracranial pressure. **Why Other Options are Incorrect:** * **B. Lumbar Puncture:** This would involve another dural puncture, potentially worsening the CSF leak and the headache. * **C. Foot end elevation:** While horizontal positioning provides symptomatic relief, foot-end elevation (Trendelenburg) is not a definitive treatment and may increase intracranial venous pressure without fixing the leak. * **D. Sumatriptan:** While used for migraines, it is not the primary treatment for PDPH. Conservative medical management usually involves hydration, caffeine, and simple analgesics (NSAIDs). **High-Yield Clinical Pearls for NEET-PG:** * **Pathophysiology:** CSF leak → Low CSF pressure → Traction on pain-sensitive intracranial structures (vessels and nerves). * **Needle Type:** Incidence is lower with **non-cutting (pencil-point)** needles like **Sprotte** or **Whitacre** compared to cutting needles (Quincke). * **Timing:** PDPH typically presents within 48–72 hours. * **Cranial Nerve Involvement:** The **6th Cranial Nerve (Abducens)** is most commonly affected due to its long intracranial course, leading to diplopia.

Q: Postoperative shivering is treated with:

Pethidine. **Explanation:** **1. Why Pethidine is the Correct Answer:** Postoperative shivering (POS) is a common complication following general or spinal anesthesia, primarily caused by the core-to-peripheral redistribution of heat and the lowering of the shivering threshold by anesthetic agents. **Pethidine (Meperidine)** is considered the **drug of choice** for treating POS. Its unique efficacy lies in its potent **agonist action at the κ (kappa) opioid receptors**, which significantly lowers the shivering threshold in the hypothalamus. While other opioids (like Morphine or Fentanyl) act primarily on μ (mu) receptors and have limited effect on shivering, Pethidine’s kappa-receptor activity makes it highly effective at low doses (10–25 mg IV). **2. Why the Other Options are Incorrect:** * **A. Diazepam:** This is a benzodiazepine used for sedation and anxiolysis. While it may reduce muscle tension, it does not act on the thermoregulatory center to stop the shivering reflex. * **B. Antihistaminics:** These are used for allergic reactions or as mild sedatives (e.g., Diphenhydramine). They have no clinical role in modulating the thermoregulatory set point. * **C. Anticholinergics:** Drugs like Atropine or Glycopyrrolate are used to reduce secretions or treat bradycardia. They do not influence the shivering mechanism. **3. High-Yield Clinical Pearls for NEET-PG:** * **Non-Pharmacological Management:** Forced-air warming (Bair Hugger) is the most effective way to prevent and treat perioperative hypothermia. * **Other Drugs for Shivering:** If Pethidine is unavailable, **Tramadol**, **Clonidine**, and **Dexmedetomidine** (α2 agonists) are effective alternatives. * **Mechanism of POS:** It increases oxygen consumption by up to 200–500%, which can be dangerous in patients with limited cardiac reserve (CAD). * **Key Association:** Pethidine is also the only opioid that possesses local anesthetic-like properties.

Q: Which of the following is NOT true regarding shivering after neuraxial anesthesia?

Shivering is associated with decreased oxygen consumption.. ### Explanation **1. Why Option D is the correct answer (The False Statement):** Shivering is an involuntary, oscillatory muscular activity aimed at generating heat through metabolic work. Contrary to the statement, shivering causes a **massive increase in oxygen consumption** (up to 200–500%) and a significant rise in carbon dioxide production. In patients with limited cardiopulmonary reserve, this increased metabolic demand can lead to hypoxemia, lactic acidosis, and myocardial ischemia. **2. Analysis of Incorrect Options (True Statements):** * **Option A:** The vigorous muscular contractions associated with shivering lead to an increase in central venous pressure, which directly translates to a rise in **intra-ocular pressure (IOP)** and **intra-cranial pressure (ICP)**. This is particularly dangerous in patients with glaucoma or head injuries. * **Option B:** **Meperidine (Pethidine)** is the gold standard and most effective drug for treating post-anesthetic shivering. It acts primarily via **kappa (κ) opioid receptors** to lower the shivering threshold. * **Option C:** Shivering triggers a sympathetic "stress response," leading to a surge in **plasma catecholamines**. This causes tachycardia and hypertension, which can precipitate arrhythmias or heart failure in susceptible individuals. **3. NEET-PG High-Yield Pearls:** * **Mechanism in Neuraxial Anesthesia:** Shivering occurs due to **core-to-peripheral redistribution of heat** (vasodilation below the block level) and a decrease in the shivering threshold by the hypothalamus. * **Drug of Choice:** Meperidine (25 mg IV). Other agents include Tramadol, Clonidine, and Dexmedetomidine. * **Non-Pharmacological Prevention:** Forced-air warming blankets and pre-warming intravenous fluids are the most effective preventive measures. * **Grading:** Shivering is often graded using the **Bedside Shivering Assessment Scale (BSAS)**.

Question 1

Which of the following is NOT a complication of massive blood transfusion?

Accepted Answer

Hypercalcemia

Answer

Hyperkalemia

Answer

Alkalosis

Answer

Acidosis

Question 2

A patient who faints during extraction should be positioned in which of the following positions?

Accepted Answer

Trendelenburg position

Answer

Lateral position

Answer

Horizontal position

Answer

Dorsosacral position

Question 3

Which of the following is true about malignant hyperthermia?

Accepted Answer

Hyperkalemia

Answer

Hypernatremia

Answer

Hypercalcemia

Answer

Hypothermia

Question 4

Vasodilation and continuous intravenous fluid administration during surgery and anesthesia can cause which of the following?

Accepted Answer

Hypothermia

Answer

Seizure

Answer

Hypotension

Answer

Vomiting

Question 5

A patient presents with sudden onset of breathlessness after subclavian vein cannulation. On examination, breath sounds are absent while the chest is hyper-resonant on percussion on one side. What is the most likely cause?

Accepted Answer

Iatrogenic pneumothorax

Answer

Subclavian vein air embolus

Answer

Malposition of cannula

Answer

Cardiac arrhythmia

Question 6

Emergence delirium with ketamine has an increased incidence in all of the following conditions except:

Accepted Answer

Dose of ketamine less than 1 mg/kg

Answer

Age greater than 15 years

Answer

Female gender

Answer

A history of personality disorders

Question 7

Which of the following is NOT a risk factor associated with post-operative nausea and vomiting following strabismus surgery?

Accepted Answer

Age less than 3 years

Answer

Duration of anesthesia greater than 30 minutes

Answer

Personal or family history of post-operative nausea and vomiting

Answer

Personal or family history of motion sickness

Question 8

A postpartum lady, 48 hours after a cesarean section, presents with headache and signs of meningism. The headache is relieved upon lying down. What is the immediate treatment?

Accepted Answer

Epidural blood patch

Answer

Lumbar puncture

Answer

Foot end elevation

Answer

Sumatriptan

Question 9

Postoperative shivering is treated with:

Accepted Answer

Pethidine

Answer

Diazepam

Answer

Antihistaminics

Answer

Anticholinergics

Question 10

Which of the following is NOT true regarding shivering after neuraxial anesthesia?

Accepted Answer

Shivering is associated with decreased oxygen consumption.

Answer

Shivering increases intra-ocular and intra-cranial pressures.

Answer

Intravenous meperidine is used in its treatment.

Answer

A marked increase in plasma catecholamines can cause cardiovascular complications.

Complications in Anesthesia — MCQs

Complications in Anesthesia — MCQs

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