Preoperative Evaluation and Management Practice Questions

Q: Which of the following drugs are commonly used in pre-anaesthetic medication?

All of the above. **Explanation:** Pre-anaesthetic medication refers to the administration of drugs prior to anesthesia to allay anxiety, provide sedation, induce amnesia, and minimize the side effects of anesthetic agents. * **Diazepam (Benzodiazepine):** It is primarily used for its **anxiolytic and sedative** properties. It also provides anterograde amnesia, which helps in reducing the patient’s psychological trauma associated with the surgical environment. * **Scopolamine (Anticholinergic/Antimuscarinic):** Also known as Hyoscine, it is used to **reduce salivary and bronchial secretions** (antisialogogue effect). It is particularly valued in pre-medication for its potent **amnestic and sedative** effects compared to atropine, and it helps prevent vagal bradycardia. * **Morphine (Opioid):** It is used to provide **pre-operative analgesia**, especially in patients with pre-existing pain or those undergoing painful procedures (e.g., regional blocks). It also contributes to sedation and reduces the dose requirement of induction agents. Since all three drugs serve specific, essential roles in preparing a patient for surgery, **Option D** is the correct answer. **High-Yield Clinical Pearls for NEET-PG:** * **Glycopyrrolate** is often preferred over Atropine/Scopolamine as an antisialogogue because it does not cross the blood-brain barrier (no CNS side effects). * **Midazolam** is the most common benzodiazepine used today due to its shorter half-life and superior water solubility. * **H2 Blockers (Ranitidine) or Proton Pump Inhibitors (Pantoprazole)** are often added to pre-medication to reduce gastric volume and acidity (Mendelson’s Syndrome prophylaxis). * **Clonidine/Dexmedetomidine (α2 agonists)** are increasingly used to provide sedation and blunt the sympathetic response to intubation.

Q: Which of the following is NOT contained in Ringer's lactate solution?

Bicarbonate. **Explanation:** Ringer’s Lactate (RL), also known as Hartmann’s solution, is a balanced salt solution used for fluid resuscitation. The correct answer is **Bicarbonate** because RL does not contain pre-formed bicarbonate. Instead, it contains **Sodium Lactate**. Once infused, the lactate is metabolized by the liver into bicarbonate, providing a buffering effect against metabolic acidosis. **Breakdown of Options:** * **Sodium (A):** RL contains approximately **130 mEq/L** of Sodium. This is slightly hyponatremic compared to plasma (135–145 mEq/L). * **Potassium (B):** RL contains **4 mEq/L** of Potassium, which mimics physiological plasma levels. * **Chloride (C):** RL contains **109 mEq/L** of Chloride. This is lower than Normal Saline (154 mEq/L), making RL less likely to cause hyperchloremic metabolic acidosis. * **Bicarbonate (D):** Bicarbonate is unstable in plastic bags and can precipitate with calcium. Therefore, lactate is used as a stable precursor. **High-Yield Clinical Pearls for NEET-PG:** 1. **Composition:** Na⁺ (130), Cl⁻ (109), Lactate (28), K⁺ (4), and **Calcium (3)**. 2. **Osmolarity:** RL is slightly **hypotonic** (273 mOsm/L) compared to plasma (285–295 mOsm/L). 3. **Contraindications:** * Avoid in **Traumatic Brain Injury (TBI)** due to hypotonicity (may increase cerebral edema). * Do not co-administer with **blood transfusions** in the same line; the Calcium in RL can bind with the Citrate anticoagulant in blood, leading to clot formation. * Use with caution in severe liver failure (impaired lactate metabolism).

Q: Plasma expanders are primarily indicated in which of the following conditions?

Severe trauma. ### Explanation **Correct Answer: B. Severe trauma** **1. Why Severe Trauma is Correct:** Plasma expanders (colloids or crystalloids) are primarily indicated for **acute hypovolemia** to restore intravascular volume and maintain tissue perfusion. In severe trauma, patients often suffer from acute hemorrhage or fluid loss, leading to hypovolemic shock. Plasma expanders increase the oncotic pressure (in the case of colloids) or provide rapid volume replacement (crystalloids), thereby stabilizing hemodynamics and preventing multi-organ failure. **2. Why Other Options are Incorrect:** * **A. Severe Anemia:** The primary deficit here is oxygen-carrying capacity (hemoglobin), not necessarily intravascular volume. The treatment of choice is **Packed Red Blood Cell (PRBC) transfusion**, not plasma expanders, which would further dilute the remaining hemoglobin. * **C. Pulmonary Edema:** This condition is characterized by fluid overload in the lungs. Administering plasma expanders would worsen the hydrostatic pressure and exacerbate the edema. Management involves **diuretics** and fluid restriction. * **D. Cardiac Failure:** In heart failure, the pump is failing, and the patient is often in a state of fluid overload (congestive heart failure). Adding volume with plasma expanders increases preload, which can lead to acute decompensation. **3. High-Yield Clinical Pearls for NEET-PG:** * **Ideal Plasma Expander:** Should be iso-oncotic with plasma, have a long half-life, be non-pyrogenic, and not interfere with blood grouping/cross-matching. * **Dextran Warning:** Dextran-40/70 can interfere with blood cross-matching and may cause acute renal failure or coagulopathy. * **Hydroxyethyl Starch (HES):** Its use is now restricted in critically ill patients due to the risk of renal injury and increased mortality. * **Gelatins:** These have the shortest duration of action among colloids and carry a higher risk of anaphylactoid reactions.

Q: A patient is undergoing preoperative airway assessment. Upon opening the mouth, visibility is limited up to the soft palate. According to the modified Mallampati classification, what is the grade of this airway?

Grade III. ### Explanation The **Modified Mallampati Classification** is a clinical tool used to predict the ease of endotracheal intubation by assessing the relationship between the size of the tongue and the oral cavity. **Correct Answer: Grade III** In **Grade III**, the clinician can visualize the **soft palate and the base of the uvula**. Since the question states visibility is limited up to the soft palate (implying the faucial pillars and the rest of the uvula are obscured by the tongue), it fits the criteria for Grade III. This grade suggests a potentially difficult airway. **Analysis of Incorrect Options:** * **Grade I (Option A):** Full visibility of the soft palate, fauces, entire uvula, and anterior/posterior tonsillar pillars. * **Grade B (Option II):** Visibility of the soft palate, fauces, and the upper portion (tip) of the uvula. * **Grade D (Option IV):** Only the hard palate is visible. The soft palate is not visible at all. This indicates a very high probability of a difficult intubation. **Clinical Pearls for NEET-PG:** * **Method:** The test is performed with the patient sitting upright, head in a neutral position, mouth opened maximally, and **tongue protruded without phonation** (saying "Ah" can falsely improve the grade). * **Samsoon and Young's Modification:** The original Mallampati had 3 classes; Samsoon and Young added Class IV. * **Predictive Value:** While a high Mallampati score (III or IV) is a good predictor of a difficult glottic view (Cormack-Lehane Grade 3 or 4), it should be used in conjunction with other tests like the **Thyromental Distance (<6 cm)** and **inter-incisor gap (<3 cm)** for better accuracy.

Q: A 65-year-old man with a history of myocardial infarction is scheduled for elective cholecystectomy. His weight is 73 kg and height is 6'2". His packed cell volume is 35%. What is the maximal allowable blood loss for the procedure?

780ml. ### Explanation The **Maximal Allowable Blood Loss (MABL)** is the amount of blood a patient can lose before their hemoglobin/hematocrit falls below a safe threshold, necessitating a blood transfusion. To calculate MABL, use the following formula: **MABL = [EBV × (Hct₀ - Hct_f)] / Hct_avg** 1. **Estimate Blood Volume (EBV):** For an adult male, EBV is approximately **70 ml/kg**. * EBV = 73 kg × 70 ml/kg = **5,110 ml**. 2. **Identify Hematocrit Values:** * Initial Hematocrit (**Hct₀**) = 35% (given). * Minimum acceptable Hematocrit (**Hct_f**): In a 65-year-old with a history of Myocardial Infarction (MI), the target hematocrit is generally **30%** to ensure adequate oxygen delivery to the myocardium. 3. **Calculate Average Hematocrit (Hct_avg):** (35 + 30) / 2 = **32.5%**. 4. **Final Calculation:** * MABL = [5,110 × (35 - 30)] / 32.5 * MABL = [5,110 × 5] / 32.5 = 25,550 / 32.5 ≈ **786 ml**. * The closest option is **780 ml (Option D)**. --- ### Analysis of Incorrect Options * **Options A, B, and C:** These values result from using incorrect EBV constants (e.g., 60 or 65 ml/kg) or assuming a lower "trigger" hematocrit (e.g., 21% or 24%). In a patient with ischemic heart disease, a higher trigger (30%) is mandatory, leading to a lower allowable loss than in a healthy young adult. --- ### High-Yield Clinical Pearls for NEET-PG * **EBV Constants:** Premature (95 ml/kg), Full-term neonate (85 ml/kg), Infant (80 ml/kg), Adult Male (70 ml/kg), Adult Female (65 ml/kg). * **Transfusion Trigger:** While 7 g/dL (Hct 21%) is the standard trigger for healthy patients, **10 g/dL (Hct 30%)** is the threshold for those with significant cardiopulmonary disease or elderly patients. * **Fluid Replacement:** Replace blood loss with crystalloids at a **3:1 ratio** or colloids/blood at a **1:1 ratio**.

Q: A nurse is assessing the motor function of an unconscious male client. Which of the following would the nurse plan to use to test the client's peripheral response to pain?

Nail bed pressure. **Explanation:** In the assessment of an unconscious patient, distinguishing between **central** and **peripheral** painful stimuli is crucial for evaluating neurological integrity and the Glasgow Coma Scale (GCS) motor component. **1. Why Nail Bed Pressure is Correct:** To test a **peripheral response**, the stimulus must be applied to a limb. Applying pressure to the nail bed (using a pen or similar object) triggers a spinal reflex or a purposeful withdrawal/localization response. This helps determine if the patient can perceive pain in the extremities and whether the motor pathway from the brain to the peripheral nerves is intact. **2. Analysis of Incorrect Options:** * **A. Sternal Rub:** This is a **central stimulus**. It involves firm pressure on the sternum and is used to assess the brain's overall arousal level rather than peripheral nerve function. * **C. Pressure on the Orbital Rim:** This involves applying pressure to the supraorbital notch. It is a **central stimulus** used to elicit a response from the cranial nerves and the brainstem. * **D. Squeezing the Sternocleidomastoid (Trapezius Squeeze):** Squeezing the trapezius muscle or the sternocleidomastoid is considered a **central stimulus** because it targets the proximal midline structures. **NEET-PG High-Yield Pearls:** * **Central Stimulus:** Used to elicit the "Best Motor Response" in GCS (e.g., Trapezius squeeze, Supraorbital pressure, Sternal rub). * **Peripheral Stimulus:** Used specifically to check for localized nerve injury or spinal cord integrity (e.g., Nail bed pressure). * **Clinical Caution:** Avoid repeated sternal rubs as they can cause bruising and tissue damage. Supraorbital pressure is contraindicated in patients with suspected frontal skull fractures. * **GCS Motor Scoring:** Localization (M5) requires the patient to move a limb toward a central stimulus, whereas Withdrawal (M4) is a flexion response to a peripheral stimulus.

Q: Which one of the following drugs has been shown to offer protection from gastric aspiration syndrome in a patient with symptoms of efflux?

Metoclopramide. **Explanation:** The primary goal in preventing **Mendelson’s Syndrome (Gastric Aspiration Syndrome)** is to reduce gastric volume and increase gastric pH. **Metoclopramide (Option B)** is the correct answer because it is a **prokinetic agent**. It acts as a dopamine ($D_2$) antagonist and stimulates the release of acetylcholine in the gastrointestinal tract. This increases the Lower Esophageal Sphincter (LES) tone and enhances gastric emptying (gastric motility). By physically clearing the stomach of liquid contents, it directly reduces the volume available for aspiration, offering protection in patients with reflux symptoms. **Analysis of Incorrect Options:** * **Ondansetron (Option A):** A $5-HT_3$ receptor antagonist used primarily as an anti-emetic. While it prevents postoperative nausea and vomiting (PONV), it has no effect on gastric pH, volume, or motility. * **Sodium Citrate (Option C):** This is a non-particulate antacid. While it effectively **increases gastric pH** (making the aspirate less acidic), it actually **increases total gastric volume**. Therefore, it does not "clear" the stomach like a prokinetic. * **Atropine (Option D):** An anticholinergic that actually **decreases** LES tone and delays gastric emptying, potentially increasing the risk of aspiration. **NEET-PG High-Yield Pearls:** * **Mendelson’s Syndrome Criteria:** Gastric volume $> 25\text{ ml}$ ($0.4\text{ ml/kg}$) and pH $< 2.5$. * **Prophylaxis Triad:** H2 blockers (e.g., Ranitidine) to decrease acid production, Metoclopramide to decrease volume, and Sodium Citrate to neutralize existing acid. * **Sodium Citrate** is preferred over particulate antacids (like Magnesium hydroxide) because if aspirated, particulate antacids cause severe foreign-body pneumonitis.

Question 1

Which of the following drugs are commonly used in pre-anaesthetic medication?

Accepted Answer

All of the above

Answer

Diazepam

Answer

Scopolamine

Answer

Morphine

Question 2

Which of the following is NOT contained in Ringer's lactate solution?

Accepted Answer

Bicarbonate

Answer

Sodium

Answer

Potassium

Answer

Chloride

Question 3

Plasma expanders are primarily indicated in which of the following conditions?

Accepted Answer

Severe trauma

Answer

Severe anemia

Answer

Pulmonary edema

Answer

Cardiac failure

Question 4

Which of the following is contraindicated in renal failure?

Accepted Answer

Midazolam

Answer

Pancuronium

Answer

Pethidine

Answer

Enflurane

Question 5

A patient has an ASA score of 3. What does this score indicate regarding their systemic disease and activity limitations?

Accepted Answer

Severe systemic disease that limits activity but is not incapacitating.

Answer

Mild systemic disease with no limitation of activity.

Answer

Moribund state with an expected survival of less than 24 hours, even with surgery.

Answer

Incapacitating systemic disease that poses a threat to life.

Question 6

In patients with liver disease, what is the preferred anesthetic agent?

Accepted Answer

Isoflurane

Answer

Halothane

Answer

Ether

Answer

None of the above

Question 7

A patient is undergoing preoperative airway assessment. Upon opening the mouth, visibility is limited up to the soft palate. According to the modified Mallampati classification, what is the grade of this airway?

Accepted Answer

Grade III

Answer

Grade I

Answer

Grade II

Answer

Grade IV

Question 8

A 65-year-old man with a history of myocardial infarction is scheduled for elective cholecystectomy. His weight is 73 kg and height is 6'2". His packed cell volume is 35%. What is the maximal allowable blood loss for the procedure?

Accepted Answer

780ml

Answer

600ml

Answer

680ml

Answer

700ml

Question 9

A nurse is assessing the motor function of an unconscious male client. Which of the following would the nurse plan to use to test the client's peripheral response to pain?

Accepted Answer

Nail bed pressure

Answer

Sternal rub

Answer

Pressure on the orbital rim

Answer

Squeezing of the sternocleidomastoid muscle

Question 10

Which one of the following drugs has been shown to offer protection from gastric aspiration syndrome in a patient with symptoms of efflux?

Accepted Answer

Metoclopramide

Answer

Ondansetron

Answer

Sodium citrate

Answer

Atropine

Preoperative Evaluation and Management — MCQs

Preoperative Evaluation and Management — MCQs

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