Complications in Anesthesia Practice Questions

Q: A 42-year-old male was undergoing elective hernioplasty. End tidal carbon dioxide (ETC02) was found to be increased. Abdominal wall gradually showed rigidity, along with the presence of tachycardia and tachypnea. Blood gas analysis shows an increased mixed acidosis, along with a serum lactate of 3.4 mmol/L. Which of the following has most likely resulted in the present situation?

Malignant hyperthermia. ***Malignant hyperthermia*** - The triad of **increased ETCO2**, **muscle rigidity**, and **tachycardia/tachypnea** during anesthesia strongly indicates malignant hyperthermia. - The **increased mixed acidosis** and **hyperlactatemia** are consequences of the uncontrolled hypermetabolic state in skeletal muscle. *Pheochromocytoma* - While it can cause **tachycardia** and **hypertension**, it does not typically present with the immediate increase in **ETCO2** and profound **muscle rigidity** seen in this scenario. - It is characterized by excessive catecholamine release, which would largely cause **hypertension** and not metabolic acidosis with a rise in ETC02 without any form of ventilation problem. *Complication of serotonergic drugs (SS)* - **Serotonin syndrome** is associated with altered mental status, autonomic instability (tachycardia, labile blood pressure), and neuromuscular abnormalities such as **hyperreflexia** and **clonus**, but typically not during surgical anesthesia with volatile agents. - **Muscle rigidity** can occur, but the dramatic increase in **ETCO2** and rapid onset during surgery point away from serotonin syndrome. *Complication of antipsychotic medication (NMS)* - **Neuroleptic Malignant Syndrome (NMS)** involves severe muscle rigidity, fever, and autonomic dysfunction, similar to malignant hyperthermia. - However, NMS usually develops over days to weeks after exposure to neuroleptics, not acutely during anesthesia, and **ETC02** is not a primary diagnostic criterion.

Q: The anesthetic agent which can cause massive hepatic necrosis?

Halothane. ***Halothane*** - Halothane can be metabolized into toxic intermediates through oxidative pathways, leading to **halothane hepatitis** or fulminant hepatic necrosis. - This idiosyncratic reaction is more likely after repeated exposures and presents as severe liver injury, possibly due to **immune-mediated mechanisms** triggered by trifluoroacetylated proteins. *N 2 O* - **Nitrous oxide** (N2O) is generally considered very safe regarding hepatic effects and does not cause massive hepatic necrosis. - Its primary metabolism involves no significant liver pathways that would generate toxic metabolites affecting hepatocytes. *Methoxyflurane* - Methoxyflurane is known to cause **nephrotoxicity** due to its metabolism to fluoride ions, which can impair renal concentrating ability. - While it can be hepatotoxic, its effects are generally less severe and less common than halothane-induced necrosis, with **renal toxicity** being its most prominent adverse effect. *Isoflurane* - Isoflurane is a commonly used volatile anesthetic with a **very low incidence of hepatotoxicity** compared to halothane. - It undergoes minimal metabolism, reducing the likelihood of producing toxic metabolites that could harm the liver.

Q: Muscle pain after anaesthesia is caused by –

Suxamethonium. ***Suxamethonium*** - **Suxamethonium** (succinylcholine) is a depolarizing neuromuscular blocker that can cause **postoperative myalgia** due to generalized muscle fasciculations before paralysis. - This muscle pain is a common side effect, especially in young, muscular patients, and is thought to be due to uncoordinated muscle contractions and microscopic muscle damage. *D-tubocurare* - **D-tubocurare** is a non-depolarizing neuromuscular blocker that **does not cause muscle fasciculations** and therefore is not typically associated with postoperative muscle pain. - Its mechanism involves competitive blockade of acetylcholine receptors at the neuromuscular junction without causing depolarization. *All of the options* - This option is incorrect because **only suxamethonium** among the listed drugs is commonly associated with muscle pain after anesthesia. - Non-depolarizing agents like d-tubocurare and vecuronium do not cause the fasciculations that lead to myalgia. *Vecuronium* - **Vecuronium** is an intermediate-acting, non-depolarizing neuromuscular blocker that achieves muscle relaxation without causing initial fasciculations. - As a result, it is not associated with the **postoperative muscle pain** seen with suxamethonium.

Q: All are management of PDPH except-

Stool softeners. ***Stool softeners*** - While **stool softeners** may be prescribed to prevent **straining** in patients experiencing PDPH, they do not directly treat the underlying cause or symptoms of PDPH. - The primary goal of PDPH management is to re-establish **CSF pressure** and relieve headache, which stool softeners do not achieve. *Analgesic + caffeine* - **Caffeine** is a common component of PDPH management as it causes **cerebral vasoconstriction**, which can help alleviate the headache. - **Analgesics** (e.g., NSAIDs, opioids) are used to manage the pain associated with PDPH. *Intravenous / oral fluids* - Increasing **fluid intake**, both oral and intravenous, helps to promote **CSF production** and potentially increase intracranial pressure, thereby alleviating PDPH symptoms. - This is a supportive measure for rehydration and to potentially restore **CSF volume**. *Upright position* - An **upright position** typically **worsens** PDPH symptoms because it increases the gravitational pull on the CSF, further lowering intracranial pressure. - Patients with PDPH are usually advised to maintain a **supine (flat)** position to minimize headache severity.

Q: Which does not cause malignant hyperthermia –

N2O. ***N2O*** - **Nitrous oxide** is a weak inhaled anesthetic and does not trigger **malignant hyperthermia** (MH). - Its mechanism of action does not involve the **ryanodine receptor** or calcium release, which are central to MH pathophysiology. *Enflurane* - **Enflurane** is a volatile inhaled anesthetic that is a known trigger for **malignant hyperthermia**. - It induces uncontrolled **intracellular calcium release** in skeletal muscle, leading to hypermetabolism. *Desflurane* - **Desflurane** is another potent volatile inhaled anesthetic and a classic trigger agent for **malignant hyperthermia**. - Its use can result in a rapid onset of MH symptoms due to its quick pharmacokinetics. *Isoflurane* - **Isoflurane** is also a volatile inhaled anesthetic and is well-established as a trigger for **malignant hyperthermia**. - Like other volatile agents, it can bind to the **ryanodine receptor** (RyR1), causing excessive calcium efflux.

Q: Mendelsons syndrome is:

Aspiration of gastric contents. ***Aspiration of gastric contents*** - Mendelson's syndrome refers to a chemical pneumonitis resulting from the **aspiration of acidic gastric contents** into the respiratory tract. - This typically occurs during **anesthesia**, sedation, or altered consciousness when airway reflexes are blunted. *Allergic reaction to inhalational anesthetics* - Allergic reactions to anesthetics are distinct from Mendelson's syndrome and involve an **immunological response**, not direct chemical burn. - Symptoms would include rash, bronchospasm, and hypotension, rather than pneumonitis from aspiration. *Aspiration of nasal secretions* - While aspiration of nasal secretions can occur, it's generally less irritating and does not typically lead to the severe inflammatory lung injury characteristic of Mendelson's syndrome, which is specifically due to **acidic gastric contents**. - Nasal secretions are usually **less acidic** and contain different microbial flora. *Complications from improper intubation* - Improper intubation can lead to complications such as **esophageal intubation**, trauma to the airway, or vocal cord damage. - These are **mechanical injuries** or misplacements and are distinct from aspiration pneumonitis caused by gastric contents.

Q: A postspinal headache is due to -

CSF leak from dura. ***CSF leak from dura*** - A post-dural puncture headache (PDPH) occurs due to the **leakage of cerebrospinal fluid (CSF)** through the puncture site in the dura mater, leading to **intracranial hypotension**. - This reduction in CSF pressure causes the brain to sag, resulting in tension on pain-sensitive structures like blood vessels and meninges, especially when the patient is in an **upright position**. *Injury to spinal cord* - Injury to the spinal cord would typically manifest as **neurological deficits** such as weakness, sensory loss, or paralysis below the level of injury, not primarily a headache. - The spinal cord itself is insensitive to pain, and direct injury is an **uncommon complication** of spinal procedures, distinct from the mechanism of headache. *Raised intracranial pressure* - Raised intracranial pressure typically causes headaches that are **worse when lying down** or with activities that increase pressure (e.g., coughing), often accompanied by focal neurological signs or papilledema. - A postspinal headache is a classic example of a headache caused by **low intracranial pressure**, making this option incorrect. *Meningitis* - Meningitis is an inflammation of the meninges, causing severe headache, **neck stiffness (nuchal rigidity)**, fever, and photophobia. - While a lumbar puncture can sometimes introduce infection (a rare complication), a typical postspinal headache is **aseptic** and primarily due to CSF leakage, not meningeal inflammation.

Q: HR-180, BP-60/40, temp-39.5°C, ETCO2-65 post induction. Most likely diagnosis:

Malignant hyperthermia. ***Malignant hyperthermia*** - The rapid onset of **tachycardia (HR-180)**, **hyperthermia (temp-39.5°C)**, and profoundly elevated **ETCO2 (65 mmHg)** immediately following anesthetic induction is the classic presentation of malignant hyperthermia. - This condition is a pharmacogenetic disorder, triggered by volatile anesthetics (e.g., isoflurane) and succinylcholine, leading to uncontrolled skeletal muscle metabolism and hypercapnia. *Thyroid storm* - While thyroid storm can cause **tachycardia** and **hyperthermia**, the sudden and dramatic rise in **ETCO2** is not a characteristic feature. - Onset is typically less abrupt and often associated with pre-existing hyperthyroidism or a precipitating event like surgery or infection, rather than immediate post-induction. *Anaphylaxis* - Anaphylaxis typically presents with **hypotension (BP-60/40)**, **tachycardia**, and often features like **bronchospasm**, **rash**, or **angioedema**. - Although it can cause **bronchospasm** leading to increased ETCO2, the extreme elevation to 65 mmHg is less typical, and **profound hyperthermia** is not a primary symptom. *Septic shock* - **Septic shock** is characterized by **hypotension** and **tachycardia**, often accompanied by **fever**, but its onset is usually prolonged over hours to days. - A sudden increase in **ETCO2** to 65 mmHg immediately post-induction is uncharacteristic for sepsis, which relates to an exaggerated, systemic inflammatory response to infection.

Q: Regarding the Royal College of Anaesthetists' 4th National Project, which of the following statements is true?

20% of cases involved ICU patients.. ***20% of cases involved ICU patients.*** - The 4th National Audit Project (NAP4) found that **20% of major airway complication events occurred in the intensive care unit (ICU)**, involving patients who were already critically ill. - This highlighted the significant burden of airway complications in the ICU setting, often related to **difficult intubation** or **tracheostomy management**. *Capnography is essential for monitoring.* - While **capnography is an essential monitoring tool** for confirming tracheal intubation and detecting dislodgement, its absence was not the primary focus or sole cause of the adverse outcomes reported in NAP4. - NAP4 emphasized multiple factors contributing to harm, not just the lack of a single monitoring device. *Airway complications are more prevalent in the operating room.* - NAP4 revealed that a significant proportion of **major airway complications occurred outside the operating room**, particularly in the emergency department, intensive care unit, and wards. - This project highlighted that **airway expertise and equipment are often less readily available** in these non-operating room settings. *ICU complications often have a higher incidence of death.* - NAP4 did indeed report a high incidence of death or brain damage following airway complications, particularly in the **ICU and emergency department**, due to factors like patient co-morbidities and delays in expert assistance. - However, the statement that 20% of cases involved ICU patients is a direct statistical finding from the report.

Q: Among the following anesthetic agents, which is most commonly associated with anaphylaxis?

Propofol. ***Propofol*** - **Propofol** is an anesthetic agent commonly associated with **anaphylaxis**, although the exact mechanism is not fully understood. - Anaphylactic reactions to propofol can range from mild cutaneous symptoms to severe cardiovascular collapse. *N2O* - **Nitrous oxide (N2O)** is a gaseous anesthetic that is generally considered to have a very **low incidence of allergic reactions** or anaphylaxis. - Its primary role is as an analgesic and sedative, rather than a potent sole anesthetic. *Althesin* - **Althesin** (alfaxalone and alphadolone) is a neurosteroid anesthetic that was formerly associated with a **high incidence of anaphylactic reactions**, leading to its withdrawal from many markets. - The high rate of anaphylaxis was largely attributed to its solvent, **Cremophor EL**. *Halothane* - **Halothane** is a volatile anesthetic that was historically linked to **halothane hepatitis**, a severe idiosyncratic liver injury, rather than anaphylaxis. - While allergic reactions are possible with any drug, halothane is not primarily known for causing anaphylactic events.

Question 1

A 42-year-old male was undergoing elective hernioplasty. End tidal carbon dioxide (ETC02) was found to be increased. Abdominal wall gradually showed rigidity, along with the presence of tachycardia and tachypnea. Blood gas analysis shows an increased mixed acidosis, along with a serum lactate of 3.4 mmol/L. Which of the following has most likely resulted in the present situation?

Accepted Answer

Malignant hyperthermia

Answer

Pheochromocytoma

Answer

Complication of serotonergic drugs (SS)

Answer

Complication of antipsychotic medication (NMS)

Question 2

The anesthetic agent which can cause massive hepatic necrosis?

Accepted Answer

Halothane

Answer

N 2 O

Answer

Methoxyflurane

Answer

Isoflurane

Question 3

Muscle pain after anaesthesia is caused by –

Accepted Answer

Suxamethonium

Answer

D-tubocurare

Answer

All of the options

Answer

Vecuronium

Question 4

All are management of PDPH except-

Accepted Answer

Stool softeners

Answer

Analgesic + caffeine

Answer

Intravenous / oral fluids

Answer

Upright position

Question 5

Which does not cause malignant hyperthermia –

Accepted Answer

N2O

Answer

Enflurane

Answer

Desflurane

Answer

Isoflurane

Question 6

Mendelsons syndrome is:

Accepted Answer

Aspiration of gastric contents

Answer

Allergic reaction to inhalational anesthetics

Answer

Aspiration of nasal secretions

Answer

Complications from improper intubation

Question 7

A postspinal headache is due to -

Accepted Answer

CSF leak from dura

Answer

Injury to spinal cord

Answer

Raised intracranial pressure

Answer

Meningitis

Question 8

HR-180, BP-60/40, temp-39.5°C, ETCO2-65 post induction. Most likely diagnosis:

Accepted Answer

Malignant hyperthermia

Answer

Thyroid storm

Answer

Anaphylaxis

Answer

Septic shock

Question 9

Regarding the Royal College of Anaesthetists' 4th National Project, which of the following statements is true?

Accepted Answer

20% of cases involved ICU patients.

Answer

Capnography is essential for monitoring.

Answer

Airway complications are more prevalent in the operating room.

Answer

ICU complications often have a higher incidence of death.

Question 10

Among the following anesthetic agents, which is most commonly associated with anaphylaxis?

Accepted Answer

Propofol

Answer

Althesin

Answer

N2O

Answer

Halothane

Complications in Anesthesia — MCQs

Complications in Anesthesia — MCQs

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