Preoperative Evaluation and Management — MCQs

A 58-year-old male factory worker scheduled to undergo a left inguinal hernia repair is noted to have a severe chronic cough. Pulmonary function tests revealed reduction of forced expiratory volume in 1 second (FEV1) and reduction of FEV1/forced vital capacity (FVC) ratio associated with emphysema. Before rescheduling surgery, which of the following would improve residual pulmonary function?

Q44Medium

Which is the most potent antiemetic agent used in the preoperative period?

Q45Easy

Which drug is used to control secretions during general anesthesia?

Q46Easy

What is the concentration of Potassium in Ringer Lactate solution?

Q47Medium

Which of the following statements regarding preoperative modification of drugs is incorrect?

Q48Medium

Which of the following patients should have their surgery deferred for further cardiac evaluation?

Q49Easy

Which of the following statements about Ringer lactate is true?

Q50Easy

Which of the following is NOT part of routine preoperative preparation?

Preoperative Evaluation and Management Indian Medical PG Practice Questions and MCQs

Question 41: Anesthetic management of a 30-year-old lady with myasthenia gravis includes all of the following except?

A. Regional anesthesia
B. Corticosteroids
C. Dose of anticholinesterase to be decreased
D. Generous doses of opioids (Correct Answer)

Explanation: **Explanation:** The anesthetic management of **Myasthenia Gravis (MG)** focuses on minimizing respiratory depression and managing the altered response to neuromuscular blocking agents. **Why "Generous doses of opioids" is the correct (except) option:** Patients with MG have significant bulbar and respiratory muscle weakness. **Opioids** cause dose-dependent respiratory depression and can suppress the cough reflex, leading to a high risk of postoperative respiratory failure and aspiration. Therefore, opioids should be used very cautiously (titrated to effect) or avoided in favor of multimodal analgesia; "generous doses" are contraindicated. **Analysis of other options:** * **Regional Anesthesia (A):** This is often the preferred technique (where applicable) as it avoids the need for systemic neuromuscular blockers and airway manipulation, reducing the risk of a myasthenic crisis. * **Corticosteroids (B):** Many MG patients are on chronic steroid therapy to manage their autoimmune condition. These should be continued perioperatively, and "stress doses" may be required to prevent adrenal insufficiency. * **Dose of Anticholinesterase (C):** Pyridostigmine is often reduced or withheld on the morning of surgery to avoid interactions with muscle relaxants and to minimize vagotonic effects (like excessive secretions/bradycardia), though this is tailored to the patient's severity. **High-Yield NEET-PG Pearls:** 1. **Muscle Relaxant Response:** MG patients are **exquisitely sensitive** to Non-depolarizing Muscle Relaxants (NDMRs) like Vecuronium (use 1/10th dose) and **resistant** to Depolarizing agents (Succinylcholine). 2. **Osserman Classification:** Used to grade the severity of MG. 3. **Predictors of Post-op Ventilation:** Disease duration >6 years, chronic respiratory disease, pyridostigmine dose >750mg/day, and Vital Capacity <2.9L. 4. **Reversal:** Sugammadex is preferred over Neostigmine to avoid cholinergic crisis.

Question 42: Which of the following is NOT a true anaesthetic implication of obesity?

A. There is a high risk of regurgitation.
B. There is a decrease in cardiac output. (Correct Answer)
C. There is an increased risk of perioperative hypoxemia.
D. There is a high risk of renal disease.

Explanation: **Explanation:** **1. Why Option B is the Correct Answer (The Concept):** In obese patients, **cardiac output actually increases**, not decreases. To meet the high metabolic demands of excess adipose tissue, there is a compensatory increase in total blood volume and stroke volume. This leads to a hyperdynamic circulation. Over time, this chronic volume overload can cause left ventricular hypertrophy and eventually "obesity cardiomyopathy," but the baseline physiological state is one of increased cardiac output. **2. Analysis of Incorrect Options:** * **Option A (High risk of regurgitation):** True. Obesity is associated with increased intra-abdominal pressure, a higher incidence of hiatal hernia, and increased gastric volume with low pH. This makes these patients "full stomach" risks, necessitating rapid sequence induction (RSI). * **Option C (Increased risk of perioperative hypoxemia):** True. Obesity reduces Functional Residual Capacity (FRC), often below the Closing Capacity (CC). This leads to atelectasis and intrapulmonary shunting. Furthermore, increased oxygen consumption ($VO_2$) causes rapid desaturation during apnea. * **Option D (High risk of renal disease):** True. Obesity is a known independent risk factor for chronic kidney disease (CKD) due to hyperfiltration injury, and it is frequently associated with comorbidities like hypertension and Type 2 Diabetes. **3. High-Yield Clinical Pearls for NEET-PG:** * **Respiratory:** The most common respiratory change is a **decrease in FRC** (specifically the Expiratory Reserve Volume). * **Airway:** Neck circumference is a better predictor of difficult intubation than BMI in obese patients. * **Induction:** Use **Lean Body Weight (LBW)** for induction agents (Propofol) and **Total Body Weight (TBW)** for maintenance and succinylcholine. * **Positioning:** The **"Ramped Position"** (Head-Elevated Laryngoscopy Position - HELP) is essential to align the oral, pharyngeal, and laryngeal axes.

Question 43: A 58-year-old male factory worker scheduled to undergo a left inguinal hernia repair is noted to have a severe chronic cough. Pulmonary function tests revealed reduction of forced expiratory volume in 1 second (FEV1) and reduction of FEV1/forced vital capacity (FVC) ratio associated with emphysema. Before rescheduling surgery, which of the following would improve residual pulmonary function?

A. Trial of ipratropium bromide bronchodilator therapy (Correct Answer)
B. Cromolyn
C. Cough suppressants
D. Bilateral carotid body resection

Explanation: ### **Explanation** The patient presents with clinical and spirometric evidence of **Chronic Obstructive Pulmonary Disease (COPD)**, specifically emphysema (obstructive pattern: ↓FEV1 and ↓FEV1/FVC ratio). In patients with COPD, the primary goal of preoperative optimization is to reduce airway resistance and improve airflow. **1. Why Option A is Correct:** In COPD, increased vagal tone is a major reversible component of airway obstruction. **Ipratropium bromide**, an inhaled anticholinergic (muscarinic antagonist), is considered the first-line bronchodilator for COPD. It works by blocking M3 receptors, leading to decreased cyclic GMP and bronchodilation. Preoperative optimization with bronchodilators improves FEV1, reduces the work of breathing, and enhances the clearance of secretions, thereby reducing postoperative pulmonary complications (PPCs). **2. Why the Other Options are Incorrect:** * **B. Cromolyn:** This is a mast cell stabilizer used primarily for the prophylaxis of extrinsic (allergic) asthma. It has no role in the acute bronchodilation or management of established emphysema. * **C. Cough Suppressants:** These are generally contraindicated preoperatively in COPD patients. Suppressing a productive cough leads to the retention of secretions, atelectasis, and an increased risk of postoperative pneumonia. * **D. Bilateral Carotid Body Resection:** While historically researched to reduce the sensation of dyspnea, it is not a standard or recommended clinical practice. It can dangerously impair the ventilatory response to hypoxia. ### **Clinical Pearls for NEET-PG:** * **Smoking Cessation:** Ideally, smoking should be stopped **8 weeks** before surgery to reduce PPCs and improve ciliary function. Stopping for only 24–48 hours reduces carboxyhemoglobin levels (shifting the oxyhemoglobin curve to the right) but may transiently increase secretions. * **Gold Standard:** For COPD, **anticholinergics** (Ipratropium) are often more effective than β2-agonists (Salbutamol). * **PFT Predictors:** An **FEV1 < 50%** of predicted or a **PaCO2 > 45 mmHg** indicates a significantly high risk for postoperative respiratory failure.

Question 44: Which is the most potent antiemetic agent used in the preoperative period?

A. Glycopyrrolate
B. Hyoscine (Correct Answer)
C. Atropine
D. Metoclopramide

Explanation: ### Explanation The correct answer is **Hyoscine (Scopolamine)**. **Why Hyoscine is the Correct Choice:** Hyoscine is a tertiary amine anticholinergic that effectively crosses the blood-brain barrier. It acts primarily on the **muscarinic receptors in the vestibular apparatus** and the nucleus tractus solitarius. Among the options provided, it is the most potent agent for preventing **Postoperative Nausea and Vomiting (PONV)**, particularly when motion sickness or vestibular stimulation is a factor. In clinical practice, it is often administered as a transdermal patch (1.5 mg) preoperatively to provide sustained antiemetic effects for up to 72 hours. **Analysis of Incorrect Options:** * **Glycopyrrolate:** A quaternary ammonium compound that does **not** cross the blood-brain barrier. While it is excellent for reducing secretions (antisialagogue), it has no central antiemetic effect. * **Atropine:** A tertiary amine that crosses the blood-brain barrier but has minimal effect on the vomiting center compared to Hyoscine. It is primarily used to treat bradycardia or as an antisialagogue. * **Metoclopramide:** A dopamine (D2) antagonist. While it has prokinetic and antiemetic properties, its potency in preventing PONV is significantly lower than Hyoscine or 5-HT3 antagonists (like Ondansetron). **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice for Motion Sickness:** Hyoscine (Scopolamine). * **Antisialagogue Potency:** Scopolamine > Glycopyrrolate > Atropine. * **Sedative Potency:** Scopolamine > Atropine > Glycopyrrolate (Zero). * **Tachycardia Potency:** Atropine > Glycopyrrolate > Scopolamine. * **Central Anticholinergic Syndrome:** Caused by Atropine/Hyoscine; treated with **Physostigmine** (a tertiary amine acetylcholinesterase inhibitor).

Question 45: Which drug is used to control secretions during general anesthesia?

A. Hyoscine
B. Glycopyrrolate (Correct Answer)
C. Pethidine
D. Lorazepam

Explanation: **Explanation:** The primary goal of using an antisialagogue in anesthesia is to reduce salivary and bronchial secretions, ensuring a clear airway and preventing laryngospasm during induction and intubation. **Why Glycopyrrolate is the correct answer:** Glycopyrrolate is a **synthetic quaternary ammonium anticholinergic**. It is the preferred drug for controlling secretions because: * **Potency:** It is more potent than atropine in reducing secretions. * **Safety Profile:** Being a quaternary ammonium compound, it does not cross the blood-brain barrier. This avoids central anticholinergic syndrome (confusion, sedation) and makes it safer for elderly patients. * **Stability:** It causes less tachycardia compared to atropine, providing better hemodynamic stability. **Analysis of Incorrect Options:** * **Hyoscine (Scopolamine):** While it has potent antisialagogue effects, it is a tertiary amine that crosses the blood-brain barrier, causing significant sedation and amnesia. It is more commonly used for motion sickness or as a pre-medication for its sedative properties. * **Pethidine:** This is an opioid analgesic used for pain relief and to treat post-operative shivering. It has no significant effect on reducing secretions. * **Lorazepam:** This is a benzodiazepine used primarily for its anxiolytic and amnestic properties during premedication; it does not possess anticholinergic properties. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice:** Glycopyrrolate is the drug of choice to be co-administered with **Neostigmine** during the reversal of neuromuscular blockade to counteract muscarinic side effects (bradycardia, salivation). * **Atropine vs. Glycopyrrolate:** Atropine is preferred in emergencies (like sinus bradycardia) due to its rapid onset, whereas Glycopyrrolate is preferred for routine secretion control. * **Contraindication:** Anticholinergics should be used with caution in patients with narrow-angle glaucoma and tachyarrhythmias.

Question 46: What is the concentration of Potassium in Ringer Lactate solution?

A. 1 mEq/L
B. 4 mEq/L (Correct Answer)
C. 2 mEq/L
D. 6 mEq/L

Explanation: **Explanation:** Ringer’s Lactate (RL), also known as Hartmann’s solution, is a balanced salt solution designed to mimic the electrolyte composition of human plasma. It is the fluid of choice for perioperative maintenance and resuscitation in most surgical cases. **Why 4 mEq/L is correct:** The concentration of **Potassium (K⁺) in Ringer’s Lactate is exactly 4 mEq/L**. This concentration is intentionally set to match the normal physiological range of potassium in human extracellular fluid (3.5–5.0 mEq/L). Because it contains potassium, RL should be used with caution in patients with renal failure or pre-existing hyperkalemia. **Analysis of Incorrect Options:** * **A (1 mEq/L) & C (2 mEq/L):** These concentrations are too low to maintain physiological homeostasis and do not reflect the standard formulation of RL. * **D (6 mEq/L):** This concentration exceeds the normal physiological limit. Infusing a fluid with 6 mEq/L of potassium as a primary maintenance fluid could potentially induce iatrogenic hyperkalemia. **High-Yield Clinical Pearls for NEET-PG:** * **Composition of RL (per Liter):** Na⁺ (130–131 mEq), Cl⁻ (109–111 mEq), K⁺ (4 mEq), Ca²⁺ (3 mEq), and Lactate (28 mEq). * **Osmolarity:** RL is slightly hypotonic compared to plasma (approx. 273 mOsm/L). * **Metabolism:** The lactate in RL is converted by the **liver** into bicarbonate, making it useful in treating metabolic acidosis. * **Contraindication:** RL should not be used as a diluent for blood transfusions because the **Calcium** in it can react with the anticoagulant (CPDA) in blood bags, leading to clot formation.

Question 47: Which of the following statements regarding preoperative modification of drugs is incorrect?

A. Lithium should be stopped 2-3 days before surgery.
B. Low-dose aspirin should be stopped 7 days before surgery. (Correct Answer)
C. Tricyclic antidepressants can be continued until the day of operation.
D. Oral anticoagulants should be stopped 4 days before surgery.

Explanation: **Explanation:** The correct answer is **B** because the current clinical guidelines recommend that **low-dose aspirin (75–150 mg)** should generally be **continued** throughout the perioperative period, especially in patients with coronary artery disease or drug-eluting stents. The risk of major adverse cardiac events (MACE) from stopping aspirin often outweighs the risk of surgical bleeding. It is only stopped (usually for 7–10 days) in specific "closed-space" surgeries where even minor bleeding is catastrophic, such as intracranial, posterior chamber of the eye, or deep spinal procedures. **Analysis of other options:** * **A. Lithium:** It is traditionally stopped **48–72 hours** before major surgery because it prolongs the action of neuromuscular blocking agents and carries a risk of toxicity due to perioperative dehydration and electrolyte shifts. * **C. Tricyclic Antidepressants (TCAs):** These can be **continued** until the day of surgery. However, the anesthesiologist must be cautious as TCAs increase sympathetic tone, potentially leading to exaggerated responses to indirect-acting sympathomimetics (like ephedrine) and an increased risk of arrhythmias. * **D. Oral Anticoagulants (e.g., Warfarin):** These are typically stopped **4–5 days** prior to surgery to allow the INR to normalize (<1.5). High-risk patients may require "bridging therapy" with Heparin. **High-Yield Clinical Pearls for NEET-PG:** * **Continue:** Beta-blockers, Calcium channel blockers, Statins, and most Antiepileptics. * **Stop on the day of surgery:** ACE inhibitors and ARBs (due to risk of refractory hypotension), and Oral Hypoglycemic Agents (Metformin is stopped 24–48 hours prior to avoid lactic acidosis). * **MAO Inhibitors:** Traditionally stopped 2 weeks prior, but modern practice often allows continuation with strict avoidance of Pethidine (risk of Serotonin Syndrome).

Question 48: Which of the following patients should have their surgery deferred for further cardiac evaluation?

A. A 60-year-old chronic smoker and diabetic with uncontrolled blood sugar and hypertension (BP=159/100).
B. A 55-year-old female patient with Mobitz type 2 heart block rhythm. (Correct Answer)
C. A 70-year-old male patient with congestive heart failure who has a history of dyspnea on exertion.
D. A 45-year-old female patient who has shortness of breath while climbing upstairs.

Explanation: This question tests your ability to identify **Active Cardiac Conditions** that necessitate the postponement of non-emergency surgery for evaluation and treatment according to the ACC/AHA guidelines. ### **Explanation of the Correct Answer** **Option B** is correct because **Mobitz Type II Second-degree AV block** is considered a high-grade heart block and an "Active Cardiac Condition." Unlike Mobitz Type I (Wenckebach), Type II is unstable, often progresses to complete heart block suddenly, and carries a high risk of perioperative cardiac arrest. Such patients require a preoperative cardiology consultation and often the placement of a permanent or temporary pacemaker before proceeding with elective surgery. ### **Analysis of Incorrect Options** * **Option A:** While the patient has multiple risk factors (smoking, diabetes, hypertension), a BP of 159/100 mmHg is classified as Stage 2 hypertension but is **not** a reason to defer surgery. Generally, surgery is deferred only if BP is >180/110 mmHg (Stage 3). * **Option C:** A history of CHF with dyspnea on exertion suggests "compensated" heart failure. If the patient is stable and not in acute/decompensated failure (e.g., no orthopnea or rales), they can often proceed after a focused assessment. * **Option D:** Shortness of breath while climbing stairs indicates a functional capacity of ≥4 METs (Metabolic Equivalents). Patients who can perform >4 METs of activity without significant symptoms generally have a low risk of perioperative cardiac events and do not require further testing. ### **High-Yield Clinical Pearls for NEET-PG** * **Active Cardiac Conditions (Defer Surgery):** Unstable angina, Decompensated CHF, Significant Arrhythmias (e.g., Mobitz II, 3rd-degree block, symptomatic SVT), and Severe Valvular Disease (especially Aortic Stenosis). * **METS Score:** If a patient can climb two flights of stairs or walk uphill (>4 METs), they usually do not need further cardiac stress testing. * **Hypertension Cut-off:** Elective surgery is typically postponed if Diastolic BP >110 mmHg or Systolic BP >180 mmHg.

Question 49: Which of the following statements about Ringer lactate is true?

A. Chloride (Cl-) concentration is 111 mEq/L
B. Sodium (Na+) concentration is 45 mEq/L
C. Potassium (K+) concentration is 5 mEq/L
D. Lactate concentration is 29 mEq/L (Correct Answer)

Explanation: **Explanation:** Ringer’s Lactate (RL), also known as Hartmann’s solution, is a balanced salt solution frequently used in perioperative fluid management. It is designed to be more physiological than Normal Saline (0.9% NaCl) by mimicking the electrolyte composition of human plasma. **1. Why Option D is Correct:** The lactate concentration in Ringer’s Lactate is exactly **28–29 mEq/L**. In the body, this lactate is metabolized by the liver into bicarbonate, which acts as a buffer against metabolic acidosis. This makes RL the fluid of choice for large-volume resuscitation and replacement of extracellular fluid losses. **2. Why the Other Options are Incorrect:** * **Option A (Chloride):** The chloride concentration in RL is **109 mEq/L**, not 111 mEq/L. This lower chloride content (compared to 154 mEq/L in Normal Saline) helps prevent hyperchloremic metabolic acidosis. * **Option B (Sodium):** The sodium concentration is **130–131 mEq/L**. A concentration of 45 mEq/L is seen in hypotonic solutions like 1/3rd Normal Saline. * **Option C (Potassium):** The potassium concentration is **4 mEq/L**, which is similar to normal plasma levels. 5 mEq/L is the upper limit of normal plasma potassium but is not the standard concentration in RL. **High-Yield Clinical Pearls for NEET-PG:** * **Osmolarity:** RL is slightly **hypotonic** (approx. 273 mOsm/L) compared to plasma (285–295 mOsm/L). * **Calcium Content:** RL contains **3 mEq/L of Calcium**. Therefore, it should **not** be administered in the same line as citrated blood products, as the calcium can bind to the citrate anticoagulant and cause clot formation. * **Contraindications:** Avoid RL in patients with severe liver disease (unable to metabolize lactate) or in cases of head injury (due to its slight hypotonicity, which may worsen cerebral edema).

Question 50: Which of the following is NOT part of routine preoperative preparation?

A. Diazepam
B. Midazolam
C. Atropine
D. Erythropoietin (Correct Answer)

Explanation: **Explanation:** The goal of routine preoperative preparation is to alleviate patient anxiety, provide sedation, and minimize autonomic reflexes or secretions. **Why Erythropoietin is the correct answer:** Erythropoietin is a glycoprotein hormone that stimulates red blood cell production. It is **not** a routine preoperative medication. Its use is strictly limited to specific clinical scenarios, such as patients with chronic kidney disease or those undergoing major elective surgery with anticipated high blood loss who refuse blood transfusions (e.g., Jehovah’s Witnesses). It requires weeks to be effective and carries risks of hypertension and thromboembolism, making it unsuitable for routine immediate preoperative use. **Why the other options are incorrect:** * **Diazepam & Midazolam (Benzodiazepines):** These are the most common agents used for **pre-anesthetic medication**. They provide anxiolysis and anterograde amnesia. Midazolam is preferred due to its shorter half-life and water solubility (less pain on injection). * **Atropine (Anticholinergic):** While no longer used "universally" for every patient, it remains a standard component of preoperative preparation to reduce salivary and bronchial secretions (antisialagogue effect) and to prevent reflex bradycardia during induction or surgery. **High-Yield NEET-PG Pearls:** * **Ideal time for Pre-medication:** Usually 60–90 minutes before induction. * **Midazolam:** Most common pre-medicant; provides excellent amnesia. * **Glycopyrrolate:** Often preferred over Atropine as an antisialagogue because it does not cross the blood-brain barrier (no central anticholinergic syndrome). * **Aspiration Prophylaxis:** Routine in "at-risk" patients using H2 blockers (Ranitidine) or Proton Pump Inhibitors (Pantoprazole) and prokinetics (Metoclopramide).

Practice by Chapter

Preoperative Assessment Framework

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ASA Physical Status Classification

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Preoperative Laboratory Testing

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Cardiovascular Evaluation

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Pulmonary Evaluation

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Assessment of the Difficult Airway

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Medication Management

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NPO Guidelines

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Perioperative Anticoagulation Management

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Premedication

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Informed Consent

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Risk Stratification

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