General Anesthesia Practice Questions

Q: Which anesthetic agent is known for providing smooth induction?

Isoflurane. ***Isoflurane*** - **Isoflurane** is frequently chosen for its capacity to induce a **smooth and rapid loss of consciousness**, primarily due to its low blood solubility which facilitates quick changes in anesthetic depth. - Its **minimal irritation** to the respiratory tract and **stable cardiovascular profile** during induction contribute to a smoother process for the patient. *Sevoflurane* - While sevoflurane also offers a **smooth and rapid induction** due to its low solubility, it is sometimes associated with a higher incidence of **airway irritation** (e.g., coughing) compared to isoflurane, especially in children. - It is known for its **pleasant odor**, making it a good choice for mask induction in pediatric patients. *Halothane* - **Halothane** provides a relatively smooth induction but has a higher risk of **hepatotoxicity** and cardiac arrhythmias, which have led to its decreased use. - Its higher blood solubility means a **slower onset and offset** compared to modern volatile agents like isoflurane. *Enflurane* - **Enflurane** can cause **CNS excitation** at deeper levels of anesthesia, potentially leading to seizures, making its induction less smooth and predictable. - It also has a greater potential to cause **myocardial depression** and arrhythmias than isoflurane.

Q: Which inhalational anesthetic agent is known to be hepatotoxic?

Halothane. ***Halothane*** - Halothane is historically known for causing **halothane hepatitis**, a severe and sometimes fatal liver injury. - This toxicity is thought to be due to its metabolism to **trifluoroacetyl (TFA) halides**, which can bind to hepatocyte proteins, leading to an immune reaction. *Enflurane* - Enflurane can cause a small amount of **nephrotoxicity** due to fluoride ion production, but it is not typically associated with significant hepatotoxicity. - Its metabolism is limited, resulting in lower fluoride levels compared to older agents but still can be a concern in patients with renal impairment. *Desflurane* - Desflurane is minimally metabolized and is considered one of the safest inhalational agents in terms of organ toxicity. - Due to its low solubility and rapid elimination, it has a very low risk of causing **organ damage**, including the liver. *Sevoflurane* - Sevoflurane is generally considered safe for the liver and is widely used, particularly in pediatric anesthesia. - While it undergoes some metabolism to fluoride ions, it is not associated with significant **hepatotoxicity** in clinical practice, though it can interact with desiccated CO2 absorbents to produce Compound A.

Q: Which inhalational anesthetic has the highest global warming potential?

Desflurane. ***Desflurane*** - **Desflurane** has the highest global warming potential among commonly used volatile anesthetics due to its high **infrared absorbance** and long **atmospheric lifetime**. - Its environmental impact is a recognized concern, leading to efforts to reduce its use in clinical practice. *Isoflurane* - **Isoflurane** has a lower global warming potential and atmospheric lifetime compared to **desflurane**. - While it contributes to greenhouse gas emissions, its impact is less significant than desflurane. *Sevoflurane* - **Sevoflurane** has the lowest global warming potential and the shortest atmospheric lifetime among the modern volatile anesthetics. - It is often considered a more **environmentally friendly** option compared to desflurane and isoflurane. *Halothane* - **Halothane** is an older inhalational anesthetic that is rarely used today due to concerns about **hepatotoxicity** and **cardiac arrhythmias**. - Although it has ozone-depleting potential due to its chlorine content, its global warming potential is less than desflurane and its clinical use is negligible.

Q: Which anaesthetic drug contributes to green house effect?

Desflurane. **Desflurane** - **Desflurane** has the highest **global warming potential (GWP)** among commonly used volatile anesthetics, primarily due to its long atmospheric half-life and potent infrared absorption. - Its environmental impact is also amplified by its high **minimum alveolar concentration (MAC)** and low blood solubility, requiring higher delivered concentrations for anesthesia. *Enflurane* - **Enflurane** has a lower GWP compared to desflurane and is less commonly used in modern practice. - While it contributes to the greenhouse effect, its impact is significantly less than that of desflurane due to differences in chemical structure and atmospheric persistence. *Sevoflurane* - **Sevoflurane** has a relatively low GWP and a short atmospheric half-life compared to desflurane, making it a more environmentally friendly option among volatile anesthetics. - Although it still contributes to atmospheric warming, its overall environmental impact is considerably less than desflurane's. *Halothane* - **Halothane** is a potent greenhouse gas but is no longer used in many parts of the world due to concerns about hepatotoxicity and its significant ozone-depleting potential. - While it contributes to atmospheric warming, its current lack of clinical use limits its ongoing contribution to the greenhouse effect compared to currently utilized agents.

Q: What is the definition of conscious sedation?

Sedation with ability to respond to verbal commands. ***Sedation with ability to respond to verbal commands*** - Conscious sedation involves a drug-induced depression of consciousness during which the patient **retains the ability to respond purposefully to verbal commands**. - This level of sedation ensures that the patient's **airway reflexes** and **ventilatory function** remain intact. *CNS depression with unconsciousness* - This describes **general anesthesia** or **deep sedation**, where the patient is unable to respond purposefully to verbal commands. - In such states, spontaneous ventilation may be **inadequate**, and **airway support** is often required. *Sedation with inability to respond to verbal commands* - This definition aligns with **deep sedation** or **general anesthesia**, where the patient's consciousness is significantly depressed. - At this level, patients may require assistance in maintaining a **patent airway** and adequate ventilation. *None of the options* - This option is incorrect because one of the provided definitions accurately describes conscious sedation. - The definition of conscious sedation is well-established in clinical practice, emphasizing the **preservation of responsiveness**.

Q: Which of the following anesthetic agents is most notable for its analgesic properties?

Ketamine. ***Ketamine*** - **Ketamine** is unique among general anesthetics for its significant **analgesic properties**, which stem from its action as an **NMDA receptor antagonist**. - Its ability to provide pain relief makes it useful in scenarios where both **anesthesia** and **analgesia** are desired, such as for painful procedures or in trauma settings. *Propofol* - While **propofol** is a widely used intravenous anesthetic, it lacks intrinsic **analgesic properties**. Its primary effects are **sedation** and **hypnosis**. - Pain during propofol injection is common, and other analgesics are usually co-administered for painful procedures. *Thiopentone* - **Thiopentone** is an ultrashort-acting barbiturate primarily used for **induction of anesthesia** due to its rapid onset and profound hypnotic effects. - It has **no analgesic properties** and can even lower the pain threshold, requiring concurrent administration of analgesics.

Q: Which of the following anesthetics is known to increase intraocular pressure?

Ketamine. ***Ketamine*** - **Ketamine** is known to increase **intraocular pressure (IOP)**, making it generally avoided in patients with **glaucoma** or those undergoing ocular surgery. - This effect is due to its influence on sympathetic nervous system activity and extraocular muscle tone. *Thiopental* - **Thiopental**, a barbiturate, typically causes a **reduction in intraocular pressure**, which can be beneficial in certain ocular procedures. - Its mechanism involves decreasing cerebral blood flow and metabolic rate, indirectly leading to a decrease in IOP. *Alfentanil* - **Alfentanil**, an opioid, generally has **minimal to no significant effect on intraocular pressure**. - Its primary actions are analgesia and sedation, without direct impact on oculomotor tone or fluid dynamics. *Propofol* - **Propofol** is known to **decrease intraocular pressure**, making it a favorable agent for ophthalmic surgery. - This effect is attributed to a reduction in cerebral blood flow and an inhibition of aqueous humor production.

Q: What is the drug of choice for reversing muscle relaxants after anesthesia?

Neostigmine. ***Neostigmine*** - **Neostigmine** is an **acetylcholinesterase inhibitor** that increases the amount of acetylcholine at the neuromuscular junction, thereby reversing the effects of non-depolarizing muscle relaxants. - It is often co-administered with an **anticholinergic agent** like atropine or glycopyrrolate to counteract its muscarinic side effects (e.g., bradycardia, increased secretions). *Pralidoxine* - **Pralidoxine (2-PAM)** is an **oxime cholinesterase reactivator** used primarily to treat organophosphate poisoning. - It works by regenerating acetylcholinesterase that has been inhibited by organophosphates, which is not the mechanism of action required for reversing typical muscle relaxants. *Atropine* - **Atropine** is an **anticholinergic drug** that blocks muscarinic acetylcholine receptors. - While it is often given with neostigmine to counteract muscarinic side effects like bradycardia, it does not directly reverse the neuromuscular blockade caused by muscle relaxants. *None of the options* - This option is incorrect because **neostigmine** is a well-established and commonly used drug for reversing non-depolarizing muscle relaxants.

Q: Phase II block is seen with:

SCh infusion. ***SCh infusion*** - A **prolonged infusion or high dose** of succinylcholine (SCh) can lead to a **Phase II block**, a desensitizing block resembling that of a non-depolarizing neuromuscular blocker. - This occurs due to the **persistent presence of SCh** at the neuromuscular junction, which initially depolarizes the endplate (Phase I) but eventually leads to **receptor desensitization** and repolarization, preventing further muscle contraction. *Single dose SCh* - A **single bolus dose of succinylcholine** typically produces a **Phase I block**, characterized by initial muscle fasciculations followed by flaccid paralysis due to persistent depolarization of the motor endplate. - It resolves relatively quickly as **succinylcholine is rapidly hydrolyzed** by pseudocholinesterase, usually not leading to a prolonged desensitization characteristic of Phase II. *Mivacurium* - **Mivacurium** is an intermediate-acting, **non-depolarizing neuromuscular blocker**. - Its mechanism of action involves **competitively binding to nicotinic acetylcholine receptors** at the neuromuscular junction, thereby preventing acetylcholine from binding and initiating muscle contraction, which is fundamentally different from a Phase II block caused by prolonged depolarization. *None of the options* - This option is incorrect because **SCh infusion** is a recognized cause of Phase II block. - The phenomenon of Phase II block is a well-established pharmacological response to **excessive and prolonged exposure** to depolarizing neuromuscular blockers like succinylcholine.

Q: Which anaesthetic agent has maximum MAC ?

Nitrous Oxide (N2O). ***Nitrous Oxide (N2O)*** - **Nitrous Oxide** has the highest **minimum alveolar concentration (MAC)** of all commonly used inhalational anesthetics, approximately 104%. - A high MAC indicates **low potency**, meaning that a large concentration is required to achieve anesthetic effects. *Ether* - **Ether** has a MAC of about 1.92%, which is significantly lower than that of Nitrous Oxide. - Its use has largely been replaced due to its flammability, slow induction, and recovery times. *Methoxyfluorane* - **Methoxyfluorane** is known for having a very low MAC, around 0.16%, making it the most potent inhalational anesthetic. - Due to its high potency and significant nephrotoxicity, its use is now very limited. *Halothane* - **Halothane** has a MAC of approximately 0.75%. - While it was a widely used inhalational anesthetic, it has largely been replaced due to concerns about **halothane hepatitis** and arrhythmogenicity.

Question 1

Which anesthetic agent is known for providing smooth induction?

Accepted Answer

Isoflurane

Answer

Halothane

Answer

Enflurane

Answer

Sevoflurane

Question 2

Which inhalational anesthetic agent is known to be hepatotoxic?

Accepted Answer

Halothane

Answer

Enflurane

Answer

Desflurane

Answer

Sevoflurane

Question 3

Which inhalational anesthetic has the highest global warming potential?

Accepted Answer

Desflurane

Answer

Isoflurane

Answer

Sevoflurane

Answer

Halothane

Question 4

Which anaesthetic drug contributes to green house effect?

Accepted Answer

Desflurane

Answer

Enflurane

Answer

Sevoflurane

Answer

Halothane

Question 5

What is the definition of conscious sedation?

Accepted Answer

Sedation with ability to respond to verbal commands

Answer

CNS depression with unconsciousness

Answer

Sedation with inability to respond to verbal commands

Answer

None of the options

Question 6

Which of the following anesthetic agents is most notable for its analgesic properties?

Accepted Answer

Ketamine

Answer

Thiopentone

Answer

Propofol

Answer

None of the options

Question 7

Which of the following anesthetics is known to increase intraocular pressure?

Accepted Answer

Ketamine

Answer

Thiopental

Answer

Alfentanil

Answer

Propofol

Question 8

What is the drug of choice for reversing muscle relaxants after anesthesia?

Accepted Answer

Neostigmine

Answer

Pralidoxine

Answer

Atropine

Answer

None of the options

Question 9

Phase II block is seen with:

Accepted Answer

SCh infusion

Answer

Single dose SCh

Answer

Mivacurium

Answer

None of the options

Question 10

Which anaesthetic agent has maximum MAC ?

Accepted Answer

Nitrous Oxide (N2O)

Answer

Ether

Answer

Methoxyfluorane

Answer

Halothane

General Anesthesia — MCQs

General Anesthesia — MCQs

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