Preoperative Evaluation and Management — MCQs

A 32-year-old ex-heroin addict with hepatitis C requires an urgent laparotomy for the treatment of a perforated duodenal ulcer. The patient is undergoing treatment with naltrexone. The results of pre-operative coagulation studies include an INR for the prothrombin time of 1.8 and a platelet count of 85,000/cubic mm. Given this scenario, which of the following post-operative analgesic techniques would be most appropriate?

Q38Easy

Which oral hypoglycemic drug should be discontinued prior to general anesthesia and surgery?

Q39Medium

Which of the following represents an abnormal preoperative pulmonary function test finding in a patient with severe kyphoscoliosis?

Q40Medium

What is the target hemoglobin level to be maintained in patients with underlying serious heart disease?

Preoperative Evaluation and Management Indian Medical PG Practice Questions and MCQs

Question 31: A patient who is a heavy smoker is scheduled for elective hernia repair. How long before surgery should smoking be stopped?

A. 4 days
B. 10 days
C. 3-4 weeks
D. 6-8 weeks (Correct Answer)

Explanation: **Explanation:** The primary goal of preoperative smoking cessation is to reduce the risk of postoperative pulmonary complications (PPCs). **1. Why 6-8 weeks is correct:** Smoking cessation for **6-8 weeks** is the minimum duration required to significantly reduce the incidence of PPCs. This timeframe allows for: * **Restoration of ciliary function:** Improving the clearance of secretions. * **Reduction in sputum production:** Decreasing airway irritability and mucus plugging. * **Improvement in small airway function:** Enhancing gas exchange and lung compliance. * **Immune recovery:** Improving macrophage function to prevent postoperative pneumonia. **2. Analysis of incorrect options:** * **A & B (4-10 days):** While short-term abstinence (12–48 hours) is beneficial for cardiovascular health (it reduces carboxyhemoglobin levels and shifts the oxyhemoglobin dissociation curve to the right, improving oxygen delivery), it is **insufficient** to reduce pulmonary complications. In fact, stopping for only 1-2 weeks may paradoxically increase secretions and coughing due to the "awakening" of cilia. * **C (3-4 weeks):** While some physiological recovery begins, clinical studies show that the risk of PPCs does not significantly drop until the 6-8 week mark. **3. High-Yield Clinical Pearls for NEET-PG:** * **12-24 hours:** Carboxyhemoglobin levels normalize; heart rate and blood pressure stabilize. * **48 hours:** Ciliary function begins to recover. * **Paradoxical effect:** Short-term cessation (<4 weeks) may lead to increased sputum production and reactive airways; however, surgery should **never** be postponed solely because a patient stopped smoking recently. * **Nicotine Replacement Therapy (NRT):** It is generally recommended to help patients quit, as the benefits of quitting outweigh the risks of nicotine during the perioperative period.

Question 32: Which of the following does not represent a significant anaesthetic problem in the morbidly obese patient?

A. Difficulties in endotracheal intubation
B. Suboptimal arterial oxygen tension
C. Increased metabolism of volatile agents
D. Decreased cardiac output relative to total body mass (Correct Answer)

Explanation: In morbid obesity, the cardiovascular system undergoes significant compensatory changes to meet the metabolic demands of excess adipose tissue. **Explanation of the Correct Answer (Option D):** Contrary to the option, morbidly obese patients actually have an **increased cardiac output (CO)**. To supply the metabolic needs of the additional tissue, stroke volume and total blood volume increase. The CO increases by approximately **20–30 mL/kg of excess body fat**. While the CO is high, the "reserve" is low, often leading to eccentric left ventricular hypertrophy and eventual "obesity cardiomyopathy." Therefore, a *decreased* cardiac output relative to mass is physiologically incorrect. **Analysis of Incorrect Options:** * **A. Difficulties in endotracheal intubation:** Obese patients often have a short, thick neck, redundant pharyngeal tissue, and limited atlanto-occipital extension, making them high-risk for difficult mask ventilation and intubation. * **B. Suboptimal arterial oxygen tension:** Functional Residual Capacity (FRC) is significantly reduced (often below closing capacity), leading to early airway closure, ventilation-perfusion (V/Q) mismatch, and shunting. This results in lower baseline PaO2. * **C. Increased metabolism of volatile agents:** Obese patients have increased stores of adipose tissue where halogenated agents can accumulate. Furthermore, there is often an increased rate of hepatic metabolism (e.g., increased defluorination of agents like halothane or sevoflurane), potentially increasing the risk of metabolite-induced organ toxicity. **High-Yield Clinical Pearls for NEET-PG:** * **Most sensitive indicator** of respiratory depression in obesity: **Functional Residual Capacity (FRC)**. * **Induction:** Always perform **Pre-oxygenation** in the **Ramped Position** (Head-Elevated Laryngoscopy Position - HELP). * **Drug Dosing:** Use **Lean Body Weight (LBW)** for induction agents (Propofol) and **Total Body Weight (TBW)** for maintenance and Suxamethonium. * **Obesity Hypoventilation Syndrome (Pickwickian Syndrome):** Defined by BMI >30, daytime hypercapnia (PaCO2 >45 mmHg), and sleep-disordered breathing.

Question 33: Which of the following medications can be continued on the day of surgery?

A. Heparin
B. Statins (Correct Answer)
C. Warfarin
D. Amitriptyline

Explanation: **Explanation:** The management of perioperative medications is a high-yield topic for NEET-PG, focusing on balancing the risk of withdrawal syndromes against the risk of surgical complications (like bleeding). **1. Why Statins (Option B) are correct:** Statins (HMG-CoA reductase inhibitors) should be **continued** on the day of surgery. Beyond their lipid-lowering effects, statins possess "pleiotropic effects," including anti-inflammatory properties and plaque stabilization. Continuing statins perioperatively reduces the risk of major adverse cardiovascular events (MACE) and postoperative mortality, especially in patients undergoing vascular surgery. **2. Why the other options are incorrect:** * **Heparin (Option A):** While Heparin has a short half-life, it is typically held prior to surgery to minimize intraoperative bleeding. For patients at high risk of thromboembolism, "bridging therapy" is used, but the dose is timed to ensure normal coagulation during the procedure. * **Warfarin (Option C):** This must be stopped **5 days** prior to surgery to allow the INR to normalize (<1.5). Failure to stop Warfarin poses a significant risk of uncontrollable surgical hemorrhage. * **Amitriptyline (Option D):** As a Tricyclic Antidepressant (TCA), it is generally **tapered and stopped** (usually 24–48 hours prior) because it can interact with anesthetic agents (e.g., sympathomimetics) leading to hypertensive crises or cardiac arrhythmias. **Clinical Pearls for NEET-PG:** * **Continue:** Antihypertensives (except ACEIs/ARBs), Beta-blockers (do not start acutely, but do not stop), Statins, and Thyroid medications. * **Stop:** ACE inhibitors/ARBs (24 hours prior to avoid refractory hypotension), Oral Hypoglycemics (on the morning of surgery), and Antiplatelets (Clopidogrel: 5–7 days prior). * **Steroids:** Never stop; patients on chronic steroids need "stress doses" to prevent adrenal crisis.

Question 34: Once pheochromocytoma is diagnosed, what is administered preoperatively?

A. Alpha adrenergic agonist
B. Alpha adrenergic blocker (Correct Answer)
C. Beta adrenergic blocker
D. Beta adrenergic blocker

Explanation: **Explanation:** The management of Pheochromocytoma is a high-yield topic in NEET-PG, focusing on the prevention of intraoperative hypertensive crises. **Why Alpha-Blockers are the Correct Choice:** Pheochromocytoma is a catecholamine-secreting tumor. Preoperative preparation requires **Alpha-adrenergic blockade** (e.g., Phenoxybenzamine or Prazosin) to be started at least 10–14 days before surgery. This achieves two goals: 1. **Vasodilation:** It counteracts the intense vasoconstriction caused by norepinephrine, thereby controlling blood pressure. 2. **Volume Expansion:** Chronic vasoconstriction leads to a contracted intravascular volume. Alpha-blockade allows for "re-expansion" of plasma volume, preventing profound hypotension after the tumor is removed. **Analysis of Incorrect Options:** * **Alpha-adrenergic agonist:** These (e.g., Phenylephrine) would cause further vasoconstriction, leading to a life-threatening hypertensive crisis. * **Beta-adrenergic blocker:** These are used **only after** adequate alpha-blockade is established. If given alone, they cause "unopposed alpha-stimulation," where the blockade of vasodilatory Beta-2 receptors leaves Alpha-1 receptors free to cause massive, lethal vasoconstriction. **Clinical Pearls for NEET-PG:** * **The Golden Rule:** Always "Alpha before Beta." Start Beta-blockers (e.g., Propranolol) only if tachycardia persists after 2–3 days of alpha-blockade. * **Roizen’s Criteria:** Used to judge the adequacy of preoperative blockade (BP <160/90 mmHg, absence of ST-T changes, and no more than one PVC every 5 minutes). * **Drug of Choice:** **Phenoxybenzamine** (non-selective, irreversible alpha-blocker) is the traditional gold standard. * **Intraoperative Crisis:** Managed with **Phentolamine** (bolus) or **Sodium Nitroprusside** (infusion).

Question 35: A 48-year-old patient with a history of stable angina becomes dyspneic after walking 3 km. To which ASA physical status classification system class does this patient belong?

A. I
B. II
C. III (Correct Answer)
D. IV

Explanation: ### Explanation The **ASA Physical Status Classification System** is a global standard used to assess a patient's preoperative physical state and predict perioperative risk. **Why Option C (ASA III) is Correct:** ASA III is defined as a patient with **severe systemic disease** that results in **functional limitation**. In this clinical scenario, the patient has stable angina (a chronic systemic condition). The key indicator is the development of dyspnea after walking 3 km. While the patient is "stable," the fact that their systemic disease limits their physical activity (functional limitation) categorizes them as ASA III. **Why Other Options are Incorrect:** * **Option A (ASA I):** Reserved for a normal, healthy, non-smoking patient with no systemic disease and minimal/no alcohol use. * **Option B (ASA II):** Represents a patient with **mild systemic disease** without substantive functional limitations. Examples include well-controlled DM/HTN, social drinking, or pregnancy. If the patient could walk long distances without symptoms, they might fall here. * **Option C (ASA IV):** Represents a patient with severe systemic disease that is a **constant threat to life**. Examples include unstable angina, recent MI (<3 months), or symptomatic CHF. **High-Yield Clinical Pearls for NEET-PG:** * **ASA V:** A moribund patient not expected to survive without the operation (e.g., ruptured aortic aneurysm). * **ASA VI:** A declared brain-dead patient whose organs are being removed for donor purposes. * **The "E" Suffix:** Added to any classification if the surgery is an **Emergency** (e.g., ASA IIE). * **Functional Capacity:** Often measured in METs (Metabolic Equivalents). Walking 3 km (roughly 2 miles) at a brisk pace is ~3-4 METs. Limitation at this level confirms "substantive" functional impairment.

Question 36: What is considered the ideal colloidal solution?

A. Dextran
B. Plasma
C. Albumin (Correct Answer)
D. Hydroxyethyl starch

Explanation: **Explanation:** The "ideal" colloid is defined as a solution that provides effective volume expansion, remains in the intravascular space for a predictable duration, and has a superior safety profile with minimal side effects. **Why Albumin is the Correct Answer:** Albumin (specifically the 5% or 25% concentration) is considered the **gold standard or "ideal" colloid** because it is a naturally occurring plasma protein. It accounts for 70–80% of the normal plasma oncotic pressure. It is non-antigenic (when human-derived), does not interfere with blood grouping or coagulation, and carries no risk of nephrotoxicity. Furthermore, it possesses antioxidant and anti-inflammatory properties, making it physiologically superior to synthetic alternatives. **Analysis of Incorrect Options:** * **Dextran:** Associated with a high risk of anaphylaxis, interference with blood cross-matching, and impairment of platelet aggregation (increased bleeding). * **Plasma (FFP):** While natural, it is not used as a primary volume expander due to the risk of transfusion-transmitted infections (TTIs), TRALI (Transfusion-Related Acute Lung Injury), and the need for ABO compatibility. * **Hydroxyethyl Starch (HES):** Synthetic colloids like HES are associated with dose-dependent coagulopathy and significant risk of acute kidney injury (AKI), leading to "black box" warnings in critically ill patients. **NEET-PG High-Yield Pearls:** * **Intravascular Half-life:** Albumin remains in the circulation for approximately 16 hours in healthy individuals. * **Colloid vs. Crystalloid:** Colloids have a smaller volume of distribution (intravascular only) compared to crystalloids, requiring less volume (1:1 ratio) for resuscitation. * **SAFE Study:** This landmark trial proved that albumin is as safe as saline for fluid resuscitation, except in patients with Traumatic Brain Injury (TBI), where it may increase mortality.

Question 37: A 32-year-old ex-heroin addict with hepatitis C requires an urgent laparotomy for the treatment of a perforated duodenal ulcer. The patient is undergoing treatment with naltrexone. The results of pre-operative coagulation studies include an INR for the prothrombin time of 1.8 and a platelet count of 85,000/cubic mm. Given this scenario, which of the following post-operative analgesic techniques would be most appropriate?

A. Local anesthetic-based epidural analgesia.
B. Ketamine patient-controlled analgesia. (Correct Answer)
C. Intramuscular Methadone.
D. Fentanyl-based epidural analgesia.

Explanation: ### Explanation This clinical scenario presents a complex challenge involving **coagulopathy** and **opioid antagonist therapy**. **1. Why Ketamine PCA is Correct:** * **Naltrexone Interaction:** Naltrexone is a long-acting competitive opioid antagonist. Standard opioids (like fentanyl or methadone) will be ineffective at normal doses and would require dangerously high levels to overcome the competitive blockade, risking sudden respiratory depression as the naltrexone wears off. * **Non-Opioid Mechanism:** Ketamine acts primarily on **NMDA receptors**, providing potent analgesia that is completely independent of the mu-opioid receptor. This makes it an ideal choice for patients on naltrexone. * **Safety in Coagulopathy:** Unlike neuraxial techniques, intravenous PCA does not carry the risk of spinal hematoma in a patient with an elevated INR (1.8) and thrombocytopenia (85,000/mm³). **2. Why the Other Options are Incorrect:** * **Options A & D (Epidural Analgesia):** These are contraindicated due to the patient’s **coagulopathy** (INR >1.5 and Platelets <100,000). Performing neuraxial anesthesia in this setting poses a high risk of **epidural hematoma**, which can lead to permanent neurological deficits. * **Option C (Intramuscular Methadone):** Methadone is an opioid agonist. Its effect will be blocked by the patient's naltrexone. Additionally, IM injections should be avoided in patients with coagulopathy due to the risk of hematoma formation. **3. Clinical Pearls for NEET-PG:** * **ASRA Guidelines:** For neuraxial blocks, a platelet count of **>100,000/mm³** and an INR **<1.5** are generally considered safe thresholds. * **Naltrexone Management:** Ideally, oral naltrexone should be discontinued **24–72 hours** before elective surgery to allow opioid receptors to become available. In urgent cases, non-opioid adjuncts (Ketamine, NSAIDs, Dexmedetomidine) are mainstay. * **Ketamine:** Known as a "dissociative anesthetic," it preserves airway reflexes and sympathetic tone, making it useful in hemodynamically unstable patients (though it should be used cautiously in severe liver disease/Hepatitis C due to hepatic metabolism).

Question 38: Which oral hypoglycemic drug should be discontinued prior to general anesthesia and surgery?

A. Pioglitazone
B. Metformin (Correct Answer)
C. Glibenclamide
D. Gliclazide

Explanation: **Explanation:** The correct answer is **Metformin**. **Why Metformin?** Metformin is a biguanide that inhibits mitochondrial respiration, leading to an increase in lactate production. During the perioperative period, factors such as hypotension, dehydration, hemorrhage, or renal hypoperfusion can occur. These conditions predispose the patient to **Lactic Acidosis**, a rare but life-threatening complication associated with Metformin. To mitigate this risk, Metformin is typically discontinued **24 to 48 hours** before elective major surgery. It is restarted only after renal function has stabilized and oral intake is resumed. **Analysis of Incorrect Options:** * **Glibenclamide & Gliclazide (Sulfonylureas):** These drugs stimulate insulin secretion and carry a high risk of **hypoglycemia** during periods of fasting (NPO status). While they are held on the **morning of the surgery**, they do not carry the same risk of metabolic acidosis as Metformin. * **Pioglitazone (Thiazolidinediones):** These drugs improve insulin sensitivity. While they can cause fluid retention, they do not pose an acute metabolic risk during anesthesia and are generally omitted only on the day of surgery. **Clinical Pearls for NEET-PG:** * **SGLT-2 Inhibitors (e.g., Empagliflozin):** These must be stopped **3–4 days** prior to surgery due to the risk of **euglycemic ketoacidosis**. * **Insulin Management:** Long-acting insulin is usually continued at a reduced dose (60-80%), while short-acting insulin is held while the patient is NPO. * **Gold Standard:** For major surgeries, the preferred method of glycemic control is a **Glucose-Insulin-Potassium (GIK) infusion** or a sliding scale insulin protocol.

Question 39: Which of the following represents an abnormal preoperative pulmonary function test finding in a patient with severe kyphoscoliosis?

A. Reduced RV and TLC (Correct Answer)
B. Reduced FEV1/FVC
C. Reduced FEV25-75
D. Increased FRC

Explanation: **Explanation:** Kyphoscoliosis is a classic example of an **Extrapulmonary Restrictive Lung Disease**. The spinal deformity leads to a distorted thoracic cage, reduced chest wall compliance, and displacement of abdominal contents, which collectively limit lung expansion. **1. Why Option A is Correct:** In restrictive lung diseases, the primary pathology is the inability to inhale a normal volume of air. This leads to a **proportional reduction in all lung volumes and capacities**. Specifically: * **TLC (Total Lung Capacity):** Reduced because the chest wall cannot expand fully. * **RV (Residual Volume):** Reduced in kyphoscoliosis due to the mechanical compression of the lungs (unlike obstructive diseases where RV increases due to air trapping). * **VC (Vital Capacity):** Significantly decreased, often used as a marker for the severity of the deformity. **2. Why Incorrect Options are Wrong:** * **B & C (Reduced FEV1/FVC and FEV25-75):** These are hallmarks of **Obstructive Lung Disease** (e.g., Asthma, COPD). In restrictive disease, the FEV1/FVC ratio is typically **normal or even increased** because both values decrease proportionately, or the increased elastic recoil of the lung tissue keeps airways open during expiration. * **D (Increased FRC):** Functional Residual Capacity is **decreased** in kyphoscoliosis. An increased FRC is seen in conditions with hyperinflation or air trapping (Obstructive diseases). **Clinical Pearls for NEET-PG:** * **PFT Pattern:** Restrictive = ↓ Volumes (TLC, VC, FRC, RV) + Normal/↑ FEV1/FVC Ratio. * **Surgical Risk:** Patients with a Vital Capacity **< 45%** of predicted or those with associated pulmonary hypertension are at high risk for postoperative respiratory failure. * **Complication:** Long-standing kyphoscoliosis leads to **cor pulmonale** and chronic alveolar hypoventilation (Type 2 Respiratory Failure).

Question 40: What is the target hemoglobin level to be maintained in patients with underlying serious heart disease?

A. 8 g/dl
B. 9 g/dl
C. 10 g/dl
D. 11 g/dl (Correct Answer)

Explanation: **Explanation:** The correct answer is **11 g/dl**. **1. Underlying Medical Concept:** In healthy individuals, the body can tolerate lower hemoglobin levels (the "restrictive" strategy of 7–8 g/dl) because the heart can increase cardiac output to compensate for reduced oxygen-carrying capacity. However, patients with **serious heart disease** (e.g., ischemic heart disease, severe valvular disease, or heart failure) have a limited "cardiac reserve." They cannot significantly increase their stroke volume or heart rate without risking myocardial ischemia or failure. To ensure adequate myocardial oxygen delivery and prevent perioperative complications, a higher "liberal" hemoglobin threshold is maintained. Current guidelines and standard anesthetic teaching (including Miller’s Anesthesia) suggest maintaining hemoglobin at **approximately 10–11 g/dl** in this specific high-risk subset. **2. Analysis of Incorrect Options:** * **A (8 g/dl):** This is the standard "restrictive" transfusion trigger for most stable, hospitalized patients without significant comorbidities. * **B (9 g/dl):** While safer than 8 g/dl, it is still considered suboptimal for patients with active ischemia or severe cardiac limitations. * **C (10 g/dl):** This is a common threshold, but in the context of NEET-PG and standard textbook definitions for "serious heart disease," **11 g/dl** is the specific target often cited to provide a safety margin. **3. Clinical Pearls for NEET-PG:** * **The "10/30 Rule":** Traditionally, transfusion was indicated if Hb <10 g/dl or Hct <30%. This is now obsolete for healthy patients but remains a relevant benchmark for those with significant cardiopulmonary disease. * **Oxygen Delivery ($DO_2$):** Remember that $DO_2 = CO \times CaO_2$. If Cardiac Output ($CO$) is fixed due to heart disease, we must maximize the Arterial Oxygen Content ($CaO_2$), which is primarily determined by Hemoglobin. * **Elderly Patients:** In patients over 65 without heart disease, a target of 9–10 g/dl is generally acceptable.

Practice by Chapter

Preoperative Assessment Framework

Practice Questions

ASA Physical Status Classification

Practice Questions

Preoperative Laboratory Testing

Practice Questions

Cardiovascular Evaluation

Practice Questions

Pulmonary Evaluation

Practice Questions

Assessment of the Difficult Airway

Practice Questions

Medication Management

Practice Questions

NPO Guidelines

Practice Questions

Perioperative Anticoagulation Management

Practice Questions

Premedication

Practice Questions

Informed Consent

Practice Questions

Risk Stratification

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free