Ambulatory Anesthesia — MCQs

Ambulatory Anesthesia Indian Medical PG Practice Questions and MCQs

Question 21: What is the anesthetic of choice for day care surgery?

A. Thiopentone
B. Nitrous oxide
C. Propofol (Correct Answer)
D. Halothane

Explanation: ### Explanation The primary goal of **Ambulatory (Day Care) Anesthesia** is to ensure a rapid, smooth recovery with minimal side effects, allowing the patient to be discharged safely on the same day. **Why Propofol is the Correct Choice:** Propofol is considered the "gold standard" for day care surgery due to its unique pharmacokinetic profile. It has a **rapid onset** and a **very short duration of action** (due to rapid redistribution and high metabolic clearance). Most importantly, it possesses significant **anti-emetic properties**, which reduces the incidence of Postoperative Nausea and Vomiting (PONV)—the leading cause of delayed discharge and unplanned hospital admission after ambulatory surgery. It also ensures a "clear-headed" recovery with minimal psychomotor impairment. **Analysis of Incorrect Options:** * **A. Thiopentone:** While it has a rapid onset, it undergoes slow metabolism and can lead to a "hangover effect" due to accumulation in fatty tissues, delaying recovery and discharge. * **B. Nitrous Oxide:** Although it has low solubility and fast elimination, it is associated with an increased risk of PONV and is a gas, not a primary induction agent for total intravenous anesthesia (TIVA). * **C. Halothane:** This inhalational agent has a slow onset/offset compared to modern agents (like Sevoflurane) and carries risks of hepatotoxicity and sensitization of the myocardium to catecholamines. **High-Yield Clinical Pearls for NEET-PG:** * **Ideal Inhalational Agent for Day Care:** Sevoflurane (due to low blood-gas solubility and non-irritant nature). * **Gold Standard for TIVA:** Propofol. * **Fastest Recovery:** Desflurane (lowest blood-gas solubility), though it can cause airway irritation. * **Discharge Criteria:** The **Aldrete Score** or **PADSS** (Post-Anesthetic Discharge Scoring System) is used to determine if a patient is fit for home discharge.

Question 22: Tracheostomy reduces dead space by which mechanism?

A. By-passing the upper airway (Correct Answer)
B. Increasing the V/Q ratio
C. Reducing airflow resistance
D. By all of the above mechanisms

Explanation: ### Explanation **Correct Option: A. By-passing the upper airway** **Mechanism:** Dead space refers to the volume of inspired air that does not participate in gas exchange. In a healthy adult, the **anatomical dead space** (approximately 2 ml/kg or 150 ml) consists of the upper airway (nose, pharynx, larynx) and the conducting lower airway (trachea, bronchi). A tracheostomy involves creating a surgical opening in the trachea (usually between the 2nd and 4th tracheal rings). By placing a tube directly into the trachea, the **entire upper airway** (nasopharynx, oropharynx, and larynx) is bypassed. This significantly shortens the path air travels, reducing the anatomical dead space by approximately **30% to 50%**. This reduction decreases the work of breathing and improves alveolar ventilation, which is particularly beneficial in patients with borderline respiratory reserve. **Analysis of Incorrect Options:** * **B. Increasing the V/Q ratio:** The Ventilation-Perfusion (V/Q) ratio is a measure of efficiency in gas exchange at the alveolar level. While reducing dead space improves effective ventilation, it does not inherently "increase" the V/Q ratio across the lungs in a physiological sense; rather, it optimizes it by reducing wasted ventilation. * **C. Reducing airflow resistance:** While a tracheostomy *does* reduce airway resistance (by bypassing the narrow glottic opening and upper airway), this is a separate physical benefit. Reducing resistance facilitates easier air movement but is not the mechanism by which dead space volume is physically removed. **High-Yield Clinical Pearls for NEET-PG:** * **Dead Space Calculation:** Anatomical dead space is roughly equal to the weight of the patient in pounds (e.g., 150 lbs = 150 ml). * **Equipment Dead Space:** In anesthesia, adding heat and moisture exchangers (HME) or long corrugated tubes *increases* mechanical dead space. * **Physiological Dead Space:** Measured using **Bohr’s Equation** ($Vd/Vt = (PaCO_2 - PeCO_2) / PaCO_2$). * **Tracheostomy vs. Intubation:** Both bypass the upper airway, but a tracheostomy reduces dead space more effectively than an endotracheal tube due to the shorter length of the tube.

Question 23: Which of the following induction agents is used to produce a 'street-fit' person following surgery?

A. Midazolam
B. Propofol (Correct Answer)
C. Alfentanyl
D. Thiopentone

Explanation: **Explanation:** The term **'street-fit'** refers to a state where a patient is sufficiently recovered from anesthesia to be discharged safely, exhibiting clear mentation, stable gait, and minimal postoperative side effects. **Why Propofol is the Correct Answer:** Propofol is the gold standard induction agent for **Ambulatory (Day-care) Anesthesia**. Its pharmacokinetic profile is characterized by a rapid onset and, more importantly, a very rapid redistribution and clearance. Unlike other agents, it is associated with a "clear-headed" recovery, minimal "hangover" effect, and significant **anti-emetic properties**. This allows patients to meet discharge criteria (the Aldrete score) much faster, making them 'street-fit' shortly after the procedure. **Analysis of Incorrect Options:** * **Midazolam:** A benzodiazepine used for premedication. It has a longer duration of action and can cause prolonged psychomotor impairment and anterograde amnesia, delaying discharge. * **Alfentanyl:** An opioid analgesic. While it has a rapid onset, opioids carry the risk of postoperative nausea, vomiting (PONV), and respiratory depression, which are detrimental to early discharge. * **Thiopentone:** A barbiturate that was previously the standard for induction. However, it has a high "hangover" effect due to its slow metabolism and accumulation in adipose tissue, leading to prolonged drowsiness. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice for Day-care Surgery:** Propofol (Induction) and Sevoflurane (Inhalation). * **Propofol Infusion Syndrome (PRIS):** Look for metabolic acidosis, rhabdomyolysis, and cardiac failure during prolonged high-dose infusions. * **Anti-emetic dose of Propofol:** 10–20 mg IV (sub-hypnotic dose). * **Pain on injection:** A common side effect of Propofol, often mitigated by using a large vein or pre-treating with Lidocaine.

Question 24: A 20-year-old patient presents in early pregnancy for medical termination of pregnancy in a day care facility. What is the anesthetic induction agent of choice?

A. Thiopentone
B. Ketamine
C. Propofol (Correct Answer)
D. Diazepam

Explanation: **Explanation:** The correct answer is **Propofol**. The primary goal of ambulatory (day-care) anesthesia is a rapid, smooth induction followed by a quick, clear-headed recovery with minimal side effects, allowing for early discharge. **Why Propofol is the drug of choice:** 1. **Pharmacokinetics:** It has a very short context-sensitive half-life and rapid redistribution, leading to the fastest recovery and "clear-headed" emergence among induction agents. 2. **Anti-emetic properties:** Post-operative nausea and vomiting (PONV) is a leading cause of delayed discharge in day-care surgery. Propofol possesses intrinsic anti-emetic properties, making it ideal for procedures like MTP where hormonal changes already increase the risk of vomiting. 3. **Suppression of airway reflexes:** It effectively suppresses laryngeal reflexes, facilitating the insertion of a Laryngeal Mask Airway (LMA), which is commonly used in short procedures. **Why other options are incorrect:** * **Thiopentone:** It has a "hangover effect" due to its slower metabolism and accumulation in fat stores, leading to delayed psychomotor recovery compared to Propofol. * **Ketamine:** Associated with emergence delirium, hallucinations, and increased secretions. It also lacks the rapid recovery profile required for day-care settings. * **Diazepam:** As a benzodiazepine, it has a long duration of action and causes significant residual sedation, making it unsuitable for rapid discharge. **Clinical Pearls for NEET-PG:** * **Gold Standard:** Propofol is the "Gold Standard" for Total Intravenous Anesthesia (TIVA) and ambulatory anesthesia. * **MTP specific:** For MTP, Propofol is preferred because it does not significantly interfere with uterine contractions (unlike high-dose volatile anesthetics). * **Pain on injection:** The most common side effect of Propofol; can be mitigated by using a large vein or pre-administering Lidocaine.

Question 25: Which is the best anesthetic agent for outpatient anesthesia?

A. Fentanyl
B. Morphine
C. Alfentanyl (Correct Answer)
D. Pethidine

Explanation: **Explanation:** The primary goal of **Ambulatory (Day-care) Anesthesia** is to ensure a rapid onset of action, stable intraoperative period, and, most importantly, a **rapid recovery** with minimal side effects to allow for early discharge. **Why Alfentanyl is the Correct Answer:** Alfentanyl is a synthetic opioid derivative of fentanyl. It is considered the best choice among the options for outpatient procedures due to its unique pharmacokinetics: * **Ultra-short duration of action:** It has a very small volume of distribution and a rapid clearance rate. * **Rapid Onset:** It has a low $pK_a$ (6.5), meaning a high fraction of the drug is unionized at physiological pH, allowing it to cross the blood-brain barrier almost instantly. * **Short Recovery Time:** Its effect wears off quickly, leading to faster mobilization and discharge compared to other opioids. **Why the Other Options are Incorrect:** * **Fentanyl:** While commonly used, it has a longer elimination half-life and a tendency to accumulate in fat stores (context-sensitive half-life), which can lead to delayed respiratory depression or drowsiness. * **Morphine:** It has a slow onset and a long duration of action (4–6 hours). It also carries a high risk of postoperative nausea and vomiting (PONV) and urinary retention, both of which are major "discharge-delaying" factors. * **Pethidine:** It has a long duration of action and produces a metabolite, **normeperidine**, which can cause CNS toxicity (seizures). It also causes significant tachycardia and PONV. **High-Yield NEET-PG Pearls:** * **Ideal Inhalational Agent for Day-care:** Desflurane (fastest recovery) or Sevoflurane. * **Ideal IV Induction Agent:** Propofol (due to its anti-emetic properties and rapid clear-headed recovery). * **Fastest Acting Opioid:** Remifentanil (metabolized by plasma esterases), but if not in options, Alfentanyl is the preferred choice for short procedures. * **Discharge Criteria:** The **Aldrete Score** or **PADSS** (Post-Anesthetic Discharge Scoring System) is used to evaluate readiness for discharge.

Question 26: A patient is scheduled for laparoscopic surgery under general anesthesia in a day care setting. Which of the following factors makes him unsuitable for day care surgery?

A. The patient has had general anesthesia in the past without complications
B. The surgical procedure is expected to last slightly over 1 hour
C. No attendant is available at home to care for the patient postoperatively (Correct Answer)
D. Home is 45 minutes away from the hospital

Explanation: ***No attendant is available at home to care for the patient postoperatively***- Discharge following **general anesthesia** (GA) in a day care setting requires a responsible adult to escort the patient home and remain with them for the subsequent **24 hours** to monitor for complications.- Lack of a competent adult caregiver is a **strict contraindication** for ambulatory surgery requiring GA, as the patient's judgment and motor skills remain significantly impaired.*Home is 45 minutes away from the hospital*- The proximity criterion for day care surgery typically specifies that the patient should live within a **reasonable travel time** (often 60–90 minutes) of the hospital for accessible emergency readmission.- A 45-minute travel time falls well within acceptable limits and therefore does not make the patient unsuitable.*The surgical procedure is expected to last slightly over 1 hour*- For most day care protocols, surgical procedures should usually last less than **2 hours** to minimize recovery time and risks associated with prolonged anesthesia.- A procedure lasting slightly over 1 hour is considered standard and fully compatible with **ambulatory surgery** guidelines.*The patient has had general anesthesia in the past without complications*- Prior uncomplicated exposure to **general anesthesia** is viewed as a favorable predictive factor, suggesting a reduced risk of rare but severe anesthetic reactions like **Malignant Hyperthermia**.- This historical data actually increases the patient's suitability for a day care setting, rather than ruling it out.

Question 27: Which of the following is the most common drug used in day care surgery/TIVA?

A. Sodium thiopentone
B. Ketamine
C. Propofol (Correct Answer)
D. Halothane

Explanation: ***Propofol***- **Propofol** is the anesthetic of choice for **TIVA** (Total Intravenous Anesthesia) and day care surgery due to its favorable pharmacokinetics, including rapid onset and smooth awakening.- Its **ultra-short duration of action** and rapid metabolic clearance ensure a quick, clear-headed recovery, which is essential for minimizing post-anesthesia care unit (PACU) time and facilitating early discharge.*Sodium thiopentone*- Although used for induction, **sodium thiopentone** has a longer context-sensitive half-time than propofol, resulting in **slower emergence** and potential for prolonged postoperative drowsiness.- Due to its slower recovery profile and higher risk of **residual sedation**, it is generally not preferred for short procedures in day care settings.*Halothane*- **Halothane** is a volatile **inhalational anesthetic** and, therefore, cannot be used for TIVA, which requires intravenous agents.- Modern volatile agents have largely replaced halothane due to the risk of severe side effects, notably cardiovascular depression and potentially fatal **halothane-induced hepatotoxicity**.*Ketamine*- **Ketamine** provides excellent analgesia and cardiovascular stability (sympathomimetic effects), but it frequently causes **psychomimetic side effects** (emergence delirium, hallucinations) during recovery, which are undesirable in day care.- Full Ketamine anesthesia often requires concurrent use with benzodiazepines (midazolam) to mitigate emergence phenomena, making it less suitable as a sole agent for smooth, rapid day care surgery recovery.

Question 28: Which of the following is used for day care surgery?

A. Thiopentone
B. Ketamine
C. Etomidate
D. Propofol (Correct Answer)

Explanation: ***Propofol*** - **Propofol** is favored for **day care surgery** due to its **rapid onset** and **rapid recovery** profile, allowing patients to be discharged quickly. - It produces a **clear-headed recovery** with less postoperative nausea and vomiting compared to other agents. *Thiopentone* - **Thiopentone** has a **longer recovery time** and greater potential for **postoperative sedation** and **nausea**, making it less suitable for day care surgery. - Its use often leads to a **delayed discharge** from the recovery unit. *Ketamine* - **Ketamine** can cause **psychomimetic effects** (e.g., hallucinations, vivid dreams) and **delirium** during emergence, which are undesirable for day care procedures. - It also leads to **increased heart rate** and **blood pressure**, which may prolong recovery and observation time. *Etomidate* - **Etomidate** is known to cause **adrenocortical suppression** and can be associated with **pain on injection** and **myoclonus**, which are not ideal for routine day care use. - While it has a relatively **stable cardiovascular profile**, these side effects limit its widespread use in short procedures where rapid, smooth recovery is paramount.

Question 29: Which of the following is an advantage of using desflurane in outpatient surgery?

A. Lower cost compared to other agents
B. Rapid emergence from anesthesia (Correct Answer)
C. Reduced risk of postoperative nausea and vomiting
D. Better hemodynamic stability

Explanation: ***Rapid emergence from anesthesia*** - Desflurane has a **very low blood-gas partition coefficient**, which means it is poorly soluble in blood and thus rapidly eliminated from the body. - This property allows for a quicker reduction in anesthetic concentration in the brain once the administration is stopped, leading to a **faster recovery of consciousness** and protective reflexes, which is highly desirable in outpatient settings. *Lower cost compared to other agents* - Desflurane is generally considered one of the **more expensive inhalational anesthetics** due to its complex manufacturing process and specialized vaporizer requirements. - While cost can vary by region and supplier, it is typically not chosen for its economic advantage compared to agents like isoflurane or sevoflurane. *Reduced risk of postoperative nausea and vomiting* - While all volatile anesthetics can contribute to **postoperative nausea and vomiting (PONV)**, desflurane has not been shown to significantly reduce its incidence compared to other agents like sevoflurane. - Factors such as patient history, co-administered opioids, and surgical type play a more dominant role in determining PONV risk. *Better hemodynamic stability* - Desflurane is known for causing **dose-dependent decreases in systemic vascular resistance and blood pressure**, and rapid increases in concentration can lead to significant sympathetic stimulation, resulting in **tachycardia and hypertension**. - Its cardiovascular profile is generally considered less stable than some other agents, particularly sevoflurane, which is often preferred for its better hemodynamic stability.

Question 30: Which of the following drugs is not typically used for day care surgery?

A. Desflurane
B. Sevoflurane
C. Atracurium (Correct Answer)
D. Propofol

Explanation: ***Atracurium*** - **Atracurium** is a **non-depolarizing neuromuscular blocking agent** used to provide muscle relaxation during surgery and intubation. - While its effects are reversible, the duration of action and potential for residual weakness or the need for a reversal agent make it **less ideal for day case surgery** where rapid recovery and discharge are paramount. *Propofol* - **Propofol** is a widely used **intravenous anesthetic** known for its rapid onset and offset of action. - Its favorable pharmacokinetic profile allows for **quick recovery and minimal hangover effect**, making it highly suitable for day case surgery. *Sevoflurane* - **Sevoflurane** is an **inhaled anesthetic** with a low blood-gas solubility, leading to rapid induction and emergence from anesthesia. - Its **predictable and quick recovery profile** makes it a preferred choice for day case surgical procedures. *Desflurane* - **Desflurane** is another **inhaled anesthetic** characterized by its very low blood-gas solubility, resulting in the **fastest awakening and recovery** among volatile anesthetics. - This rapid emergence is highly beneficial for day case surgery, facilitating **prompt patient discharge**.

Practice by Chapter

Patient Selection for Ambulatory Surgery

Practice Questions

Preoperative Assessment for Outpatients

Practice Questions

Anesthetic Techniques for Ambulatory Surgery

Practice Questions

Fast-Track Recovery Protocols

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Post-Discharge Analgesia

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Preventing PONV in Outpatients

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Perioperative Management of Sleep Apnea

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Discharge Criteria

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Common Complications After Ambulatory Surgery

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Management of Diabetic Patients

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Geriatric Ambulatory Anesthesia

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Quality Improvement in Ambulatory Surgery

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