Complications in Anesthesia Practice Questions

Q: Malignant hyperthermia is due to

All of the options. ***All of the options*** - Malignant hyperthermia is a rare, **life-threatening condition** triggered by exposure to certain anesthetic agents, including **volatile inhalational anesthetics** (like isoflurane and halothane) and the **depolarizing muscle relaxant succinylcholine (scoline)**. - The condition is characterized by a rapid, uncontrollable increase in body temperature, muscle rigidity, and metabolic acidosis due to an uncontrolled release of **calcium** from the sarcoplasmic reticulum in muscle cells. *Isoflurane* - **Isoflurane** is a **volatile inhalational anesthetic** known to be a potent trigger for malignant hyperthermia in susceptible individuals. - It works by affecting ion channels in nerve cells, but in MH-susceptible individuals, it can induce massive calcium release in skeletal muscle. *Halothane* - **Halothane**, another **volatile inhalational anesthetic**, was historically one of the most common triggers for malignant hyperthermia. - While it is less commonly used today due to its potential for liver toxicity and cardiac arrhythmias, it remains a significant trigger for MH. *Scoline* - **Scoline** (also known as **succinylcholine**) is a **depolarizing muscle relaxant** and is a well-known trigger for malignant hyperthermia. - It acts on acetylcholine receptors, causing initial muscle fasciculations followed by prolonged relaxation, but in MH-susceptible patients, it can initiate an uncontrolled calcium release in muscle cells.

Q: Most preferred safe inducing agent in malignant hyperthermia-susceptible patients is

Propofol. **Propofol** - Propofol is a **non-triggering agent** for malignant hyperthermia (MH) and is considered safe for use in susceptible patients. - It is a commonly used intravenous anesthetic that does not interfere with the **ryanodine receptor** (RyR1) or calcium homeostasis in skeletal muscle, which are central to MH pathophysiology. *Halothane* - Halothane is a **volatile anesthetic** that is a potent trigger for malignant hyperthermia. - It directly causes excessive calcium release from the **sarcoplasmic reticulum** in susceptible individuals, leading to uncontrolled muscle contraction and hypermetabolism. *Thiopentone* - Thiopentone, while an intravenous anesthetic, is still considered to have a **theoretical, albeit rare, risk** of triggering MH due to historical reports and its structural similarity to some triggers, though it's generally considered less risky than volatile agents. - However, newer, safer alternatives like propofol are preferred to completely avoid any potential risk in MH-susceptible patients. *Etomidate* - Etomidate is an intravenous anesthetic that is generally considered **safe** in malignant hyperthermia-susceptible patients as it also does not trigger the condition. - While safe, **propofol is often preferred** due to its more favorable pharmacokinetic profile for continuous infusion and broader applicability in induction and maintenance of anesthesia.

Q: All the following cause malignant hyperpyrexia except?

N20. ***N2O*** - **Nitrous oxide (N2O)**, or laughing gas, is an inhaled anesthetic that does not trigger **malignant hyperthermia (MH)**. - It is often used as a carrier gas or adjunct during anesthesia, even in patients susceptible to MH, as it does not affect **ryanodine receptors**. *Methoxyflurane* - **Methoxyflurane** is a volatile inhaled anesthetic known to trigger **malignant hyperthermia (MH)** in susceptible individuals. - It causes an uncontrolled release of **calcium** from the sarcoplasmic reticulum in muscle cells, leading to severe hypermetabolism. *Isoflurane* - **Isoflurane** is a commonly used volatile inhaled anesthetic that can induce **malignant hyperthermia (MH)** in genetically predisposed individuals. - Like other volatile agents, it activates **ryanodine receptors** in skeletal muscle, leading to excessive muscle contraction and heat production. *Halothane* - **Halothane** is a potent volatile inhaled anesthetic historically associated with a high incidence of triggering **malignant hyperthermia (MH)**. - Its use has largely been replaced by newer agents due to concerns about MH and **hepatotoxicity**.

Q: Drug causing malignant hyperthermia:(Asked twice in the exam)

Suxamethonium. ***Suxamethonium*** - **Suxamethonium** (succinylcholine) is a potent trigger for **malignant hyperthermia** (MH) in susceptible individuals due to its depolarizing action on skeletal muscle. - MH is a pharmacogenetic disorder characterized by a rapid and uncontrolled increase in **skeletal muscle metabolism**, leading to severe hyperthermia, muscle rigidity, and acidosis. *Thiopentone* - **Thiopentone** is an intravenous anesthetic that acts as a GABA-A receptor agonist, primarily causing central nervous system depression. - It is **not associated** with triggering malignant hyperthermia. *Propofol* - **Propofol** is a widely used intravenous anesthetic known for its rapid onset and recovery. - It is **not a known trigger** for malignant hyperthermia and is often considered a safe alternative for susceptible patients. *Cisatracurium* - **Cisatracurium** is a nondepolarizing neuromuscular blocker that competitively antagonizes acetylcholine at the neuromuscular junction. - It does **not trigger malignant hyperthermia** and is frequently used in patients with a history of MH.

Q: Which of the following is not seen in scoline apnea?

It occurs due to deficiency of acetylcholinesterase. ***It occurs due to deficiency of acetylcholinesterase*** - **Scoline apnea** is caused by a deficiency of **pseudocholinesterase (butyrylcholinesterase)**, not acetylcholinesterase. - **Pseudocholinesterase** is responsible for metabolizing **succinylcholine**, while acetylcholinesterase breaks down acetylcholine at the neuromuscular junction. *It is due to succinylcholine* - **Scoline apnea** is indeed triggered by the administration of **succinylcholine** in individuals with a genetic defect in **pseudocholinesterase**. - Without proper metabolism by pseudocholinesterase, succinylcholine prolongs its action, leading to prolonged neuromuscular blockade. *Patients usually do not die of scoline apnea if they are properly managed* - With appropriate management, which involves **mechanical ventilation** until the succinylcholine is metabolized, patients typically recover fully from scoline apnea. - The primary risk is respiratory failure due to prolonged paralysis, which can be managed by supportive care. *It can be inherited* - The deficiency of **pseudocholinesterase** that causes scoline apnea is an **autosomal recessive inherited disorder**. - Genetic testing can identify individuals who are at risk for this condition.

Q: Anaesthetic death rate more than what level calls for scrutiny of staff or equipment?

1 in 5000. ***1 in 5000*** - Historically, an anaesthetic death rate exceeding **1 in 5,000** was considered a benchmark for initiating scrutiny into staffing, equipment, and protocols. - This threshold indicates a potential systemic issue rather than isolated incidents, necessitating a thorough review to ensure **patient safety**. *1 in 500* - A death rate of **1 in 500** is significantly higher than accepted norms for anaesthesia and would be considered an exceptionally alarming rate, indicating severe and immediate concerns about safety. - This rate would suggest a widespread and critical failure in care, far exceeding the threshold for mere "scrutiny." *1 in 1000* - While concerning, a death rate of **1 in 1,000** is still much higher than the point at which detailed scrutiny is typically triggered for anaesthetic practice. - Modern anaesthesia aims for much lower mortality rates, so even this figure would warrant investigation but doesn't precisely match the historical threshold for concern. *None of the options* - The option is incorrect because **1 in 5000** is indeed a recognized threshold that historically prompted scrutiny of anaesthetic practice. - This standard has been an important reference point, although modern practice strives for even lower mortality rates.

Q: Problems which may result from hypotensive anesthesia include:

All of the options. ***All of the options*** - Hypotensive anesthesia is a technique used to reduce **blood pressure** during surgery, aiming to decrease **blood loss** and improve the **surgical field visibility**. - While beneficial, it carries inherent risks including **deep vein thrombosis (DVT), reactionary hemorrhage**, and complications like **retraction anemia** if not managed properly. *Deep vein thrombosis (DVT)* - While hypotension might seem to reduce the risk by lowering **blood flow velocity**, prolonged immobility and potential for **venous stasis** during any surgery, especially under hypotension, can increase DVT risk. - The combination of **endothelial dysfunction** and **hypercoagulability** often seen in surgical patients, coupled with reduced peripheral blood flow due to hypotension, can contribute to DVT formation. *Reactionary hemorrhage* - This is a common post-operative complication where bleeding restarts hours after surgery. With hypotensive anesthesia, **blood vessels** are constricted and may not be actively bleeding during the surgery. - As the patient's **blood pressure** returns to normal post-operatively, these previously undetected bleeds can manifest as significant **hemorrhage** due to the increased pressure. *Retraction anemia* - This term is less commonly used in medical literature. However, it likely refers to the complications arising from prolonged tissue retraction during surgery, which, when combined with reduced **perfusion** from hypotensive anesthesia, can lead to **tissue ischemia** or damage akin to anemia in the affected area. - The reduced **oxygen delivery** to tissues during hypotensive states, especially when further compromised by retraction, may result in localized tissue injury or contribute to systemic complications if severe or prolonged.

Q: Which of the following is the most potent trigger of malignant hyperthermia?

Halothane. ***Halothane*** - **Halothane** is a volatile anesthetic agent and the **most potent trigger** of malignant hyperthermia, directly acting on the **ryanodine receptor (RyR1)** to cause massive calcium release from the sarcoplasmic reticulum. - It has extensive historical documentation as the **primary MH trigger** and is used as the reference standard in MH susceptibility testing. *Suxamethonium* - **Suxamethonium** (succinylcholine) is a depolarizing neuromuscular blocking agent that can trigger malignant hyperthermia but is considered a **secondary trigger** compared to volatile anesthetics. - While it can independently cause MH episodes, volatile agents like **halothane** are recognized as more potent and primary triggers in current medical literature. *Thiopentone* - **Thiopentone** (thiopental) is an intravenous barbiturate anesthetic that is **safe** in patients susceptible to malignant hyperthermia. - It does not interact with the **ryanodine receptor (RyR1)** or cause uncontrolled calcium release, making it a preferred induction agent in MH-susceptible patients. *Isoflurane* - **Isoflurane** is a volatile anesthetic agent and a **potent trigger** of malignant hyperthermia, similar to halothane in its mechanism of action. - While equally potent as halothane, **halothane** is considered the classic reference trigger due to its historical significance and extensive research documentation.

Q: Malignant hyperthermia is most commonly precipitated by:

Succinyl choline. ***Succinyl choline*** - **Malignant hyperthermia** is an inherited disorder characterized by a rapid and severe rise in body temperature, muscle rigidity, and other metabolic derangements, most commonly triggered by **volatile anesthetic agents** (like halothane, sevoflurane) and the depolarizing muscle relaxant **succinylcholine**. - **Succinylcholine** triggers uncontrolled calcium release from the sarcoplasmic reticulum in susceptible individuals, leading to sustained muscle contraction and excessive heat production. *Dantrolene sodium* - **Dantrolene sodium** is the specific **antidote** for malignant hyperthermia, acting to inhibit calcium release from the sarcoplasmic reticulum. - It is used to **treat** malignant hyperthermia, not to precipitate it. *Gallamine* - **Gallamine** is a historical example of a **nondepolarizing neuromuscular blocker**; these agents generally do not trigger malignant hyperthermia. - It works by competing with acetylcholine at the neuromuscular junction, not by direct calcium release. *Pancuronium* - **Pancuronium** is a **nondepolarizing neuromuscular blocker** that blocks acetylcholine receptors, but it is not known to trigger malignant hyperthermia. - Like other nondepolarizing agents, it does not directly cause the sustained muscle contraction seen in malignant hyperthermia.

Question 1

Malignant hyperthermia is due to

Accepted Answer

All of the options

Answer

Isoflurane

Answer

Halothane

Answer

Scoline

Question 2

Most preferred safe inducing agent in malignant hyperthermia-susceptible patients is

Accepted Answer

Propofol

Answer

Halothane

Answer

Thiopentone

Answer

Etomidate

Question 3

All the following cause malignant hyperpyrexia except?

Accepted Answer

N20

Answer

Methoxyflurane

Answer

Isoflurane

Answer

Halothane

Question 4

Drug causing malignant hyperthermia:(Asked twice in the exam)

Accepted Answer

Suxamethonium

Answer

Thiopentone

Answer

Propofol

Answer

Cisatracurium

Question 5

Which of the following is not seen in scoline apnea?

Accepted Answer

It occurs due to deficiency of acetylcholinesterase

Answer

It is due to succinylcholine

Answer

Patients usually do not die of scoline apnea if they are properly managed

Answer

It can be inherited

Question 6

Anaesthetic death rate more than what level calls for scrutiny of staff or equipment?

Accepted Answer

1 in 5000

Answer

1 in 500

Answer

1 in 1000

Answer

None of the options

Question 7

Problems which may result from hypotensive anesthesia include:

Accepted Answer

All of the options

Answer

Deep vein thrombosis

Answer

Reactionary hemorrhage

Answer

Retraction anemia

Question 8

Which of the following is the most potent trigger of malignant hyperthermia?

Accepted Answer

Halothane

Answer

Thiopentone

Answer

Isoflurane

Answer

Suxamethonium

Question 9

Malignant hyperthermia is most commonly precipitated by:

Accepted Answer

Succinyl choline

Answer

Dantrolene sodium

Answer

Gallamine

Answer

Pancuronium

Question 10

A 12-year-old boy with a femur fracture after a motor vehicle collision undergoes operative repair. After induction of anesthesia, he develops a fever of 40degC (104degF), shaking rigors, and blood-tinged urine. Which of the following is the best treatment option?

Accepted Answer

Administration of dantrolene sodium and termination of the procedure

Answer

Administration of intravenous steroids and an antihistamine agent with continuation of the procedure

Answer

Administration of dantrolene sodium and continuation with the procedure

Answer

Alkalinization of the urine, administration of mannitol, and continuation with the procedure

Complications in Anesthesia — MCQs

Complications in Anesthesia — MCQs

On this page

Practice by Chapter

Want unlimited practice?