Postoperative Care — MCQs

Postoperative Care Indian Medical PG Practice Questions and MCQs

Question 21: Which of the following drugs is believed to be effective in the treatment of postoperative shivering?

A. Ondansetron
B. Diclofenac sodium
C. Pethidine (Correct Answer)
D. Paracetamol

Explanation: **Explanation:** Postoperative shivering (POS) is a common complication occurring in up to 40% of patients recovering from general or regional anesthesia. It is primarily a thermoregulatory response to perioperative hypothermia, though it can also occur due to the effects of volatile anesthetics on the hypothalamus. **Why Pethidine is the Correct Answer:** **Pethidine (Meperidine)** is considered the **gold standard** and the most effective drug for treating postoperative shivering. Unlike other opioids, pethidine has unique **agonist activity at the κ (kappa) opioid receptors** and also acts on α-2 adrenoceptors. These actions significantly lower the shivering threshold (the core temperature at which the body initiates shivering) more effectively than it lowers the vasoconstriction threshold. A low dose (10–25 mg IV) usually stops shivering within minutes. **Analysis of Incorrect Options:** * **Ondansetron:** While some studies suggest 5-HT3 antagonists may have a minor role in preventing shivering by modulating central temperature regulation, they are not the primary treatment of choice compared to pethidine. * **Diclofenac Sodium & Paracetamol:** These are Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and antipyretics. They work by inhibiting prostaglandin synthesis to reduce fever (resetting an elevated set-point), but they do not influence the thermoregulatory shivering threshold in a hypothermic postoperative patient. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism of Shivering:** Volatile anesthetics cause peripheral vasodilation, leading to a redistribution of heat from the core to the periphery. * **Other Drugs for Shivering:** Clonidine (α-2 agonist), Tramadol, and Dexmedetomidine are also used, but Pethidine remains the classic MCQ answer. * **Adverse Effects of Shivering:** It increases oxygen consumption by up to 200–500%, which can be critical in patients with limited cardiac reserve (risk of myocardial ischemia). * **Non-Pharmacological Treatment:** Forced-air warming blankets (Bair Hugger) are the most effective preventive measure.

Question 22: What is the most common rhythm disturbance during the early post-operative period?

A. Bradycardia
B. Ventricular fibrillation
C. Tachycardia (Correct Answer)
D. Complete heart block

Explanation: **Explanation:** **Sinus tachycardia** is the most frequently encountered cardiac rhythm disturbance in the early postoperative period. This is primarily due to a heightened sympathetic nervous system response triggered by various physiological stressors. **Why Tachycardia is the Correct Answer:** The early postoperative phase (recovery room/PACU) is characterized by several stimuli that increase catecholamine release. The most common triggers include: * **Pain:** Inadequate analgesia is the leading cause of postoperative tachycardia. * **Hypovolemia:** Due to surgical blood loss or inadequate fluid replacement. * **Sympathetic Stimulation:** Resulting from emergence from anesthesia, tracheal extubation, or bladder distension. * **Hypoxia and Hypercapnia:** Respiratory insufficiency leads to compensatory tachycardia. **Analysis of Incorrect Options:** * **Bradycardia:** While it can occur due to residual effects of opioids, neostigmine (if not properly reversed with anticholinergics), or the oculocardiac reflex, it is statistically less common than tachycardia. * **Ventricular Fibrillation (VF):** This is a terminal, life-threatening arrhythmia. While it can occur in patients with severe electrolyte imbalances or myocardial ischemia, it is rare in the general postoperative population. * **Complete Heart Block:** This is a severe conduction defect usually seen in patients with pre-existing structural heart disease or during specific cardiac surgeries; it is not a common routine postoperative finding. **High-Yield Clinical Pearls for NEET-PG:** * **First Step in Management:** Always treat the underlying cause (e.g., provide analgesia for pain, fluids for hypovolemia, or oxygen for hypoxia) rather than just suppressing the heart rate. * **Most Common Arrhythmia requiring treatment:** While sinus tachycardia is most common overall, **Atrial Fibrillation** is the most common *new-onset* sustained arrhythmia, especially after thoracic or cardiac surgery. * **Key Association:** Postoperative tachycardia increases myocardial oxygen demand and can precipitate ischemia in high-risk patients.

Question 23: In intravenous hyperalimentation, which of the following are administered?

A. Hypertonic saline
B. Fats
C. Amino acids (Correct Answer)
D. Dextrose

Explanation: **Explanation:** Intravenous hyperalimentation, commonly known as **Total Parenteral Nutrition (TPN)**, is the intravenous administration of all necessary nutrients to patients who cannot achieve adequate nutrition through the enteral route. The primary goal is to maintain a positive nitrogen balance and prevent muscle wasting. **Why Amino Acids are the Correct Answer:** In the context of this specific question (often sourced from classic medical entrance exams), **Amino Acids** are highlighted as the essential component for "hyperalimentation" because they provide the building blocks for protein synthesis. While TPN is a mixture, the term "hyperalimentation" historically emphasizes the aggressive provision of nitrogen (via amino acids) alongside calories to reverse catabolic states. **Analysis of Incorrect Options:** * **Hypertonic Saline (A):** This is used for treating severe hyponatremia or reducing intracranial pressure, not for nutritional support. * **Fats (B) & Dextrose (D):** While both are vital components of a standard TPN regimen (Dextrose as the primary carbohydrate source and Fats as a concentrated energy source), they are often considered "caloric supplements." In many standardized MCQ formats for this topic, Amino Acids are prioritized as the definitive "nutritive" element that defines the "alimentation" (nourishment) aspect of the therapy. **NEET-PG High-Yield Pearls:** * **Route:** TPN is typically administered via a **Central Venous Line** (e.g., Subclavian vein) because the high osmolarity (>800-900 mOsm/L) would cause thrombophlebitis in peripheral veins. * **Most Common Complication:** Catheter-related sepsis (usually *Staphylococcus aureus* or *Candida*). * **Most Common Metabolic Complication:** Hyperglycemia. * **Refeeding Syndrome:** Characterized by severe **Hypophosphatemia**, hypomagnesemia, and hypokalemia when nutrition is restarted in a starved patient. * **Monitoring:** Liver function tests should be monitored as TPN can cause cholestasis and fatty liver.

Question 24: A female, 12 hours post open cholecystectomy under general anesthesia, presents with dyspnea and crepitations in the right lower lobe. What is the probable cause?

A. Drug-induced collapse
B. Atelectasis (Correct Answer)
C. Pulmonary edema
D. Myocardial infarction

Explanation: ### Explanation **Correct Option: B. Atelectasis** Atelectasis (alveolar collapse) is the most common cause of postoperative fever and respiratory distress within the first **24–48 hours** after surgery. * **Mechanism:** In upper abdominal surgeries (like open cholecystectomy), diaphragmatic dysfunction, pain-induced splinting, and the effects of general anesthesia lead to shallow breathing and decreased functional residual capacity (FRC). This results in the collapse of small airways, typically in the basal lobes. * **Clinical Presentation:** Patients present with dyspnea, tachypnea, and characteristic **fine crepitations** (crackles) over the affected area. **Why other options are incorrect:** * **A. Drug-induced collapse:** While opioids can cause respiratory depression, they typically present with a decreased respiratory rate (bradypnea) and sedation rather than localized crepitations. * **C. Pulmonary edema:** This usually presents with bilateral diffuse crackles, frothy sputum, and signs of fluid overload or cardiac failure, rather than localized findings in the right lower lobe. * **D. Myocardial infarction:** While possible, it is rare in a young female post-cholecystectomy without prior history. It would more likely present with chest pain and ECG changes rather than isolated basal crepitations. **High-Yield Clinical Pearls for NEET-PG:** * **Timeline:** Atelectasis is the most common cause of fever on **Postoperative Day 1 (POD 1)**. * **Risk Factors:** Upper abdominal and thoracic surgeries carry the highest risk due to proximity to the diaphragm. * **Prevention/Treatment:** Incentive spirometry, early mobilization, and adequate analgesia (to prevent splinting) are the mainstays of management. * **Mnemonic (5 W’s of Post-op Fever):** **W**ind (Atelectasis - Day 1-2), **W**ater (UTI - Day 3), **W**alking (DVT/PE - Day 5), **W**ound (Infection - Day 7), **W**onder drugs (Drug fever).

Question 25: A patient who underwent surgery under general anesthesia without intraoperative complications complains of respiratory difficulty and low PO2 postoperatively. The patient is unable to lift their head or legs. What is the most likely cause?

A. Prolonged action of muscle relaxant (Correct Answer)
B. Respiratory acidosis
C. Pulmonary embolism
D. Fentanyl-induced chest rigidity

Explanation: ### Explanation The clinical presentation of respiratory difficulty combined with the **inability to lift the head or legs** (skeletal muscle weakness) in the immediate postoperative period is a classic sign of **Residual Neuromuscular Blockade** (Prolonged action of muscle relaxants). **1. Why Option A is Correct:** Muscle relaxants (like Vecuronium or Atracurium) target nicotinic acetylcholine receptors at the neuromuscular junction. If these are not fully reversed (e.g., inadequate Neostigmine dose) or if the patient has impaired metabolism (e.g., pseudocholinesterase deficiency for Succinylcholine), residual paralysis occurs. The **"5-second head lift"** test is a standard clinical bedside assessment; the inability to perform this indicates that at least 50% of receptors are still occupied, leading to hypoventilation and low $PO_2$. **2. Why Other Options are Incorrect:** * **Respiratory Acidosis:** This is a *consequence* of hypoventilation, not the primary cause of the motor weakness described. * **Pulmonary Embolism:** While it causes low $PO_2$ and respiratory distress, it does not cause symmetrical skeletal muscle paralysis (inability to lift limbs). * **Fentanyl-induced Chest Rigidity:** This typically occurs during **induction** (rapid IV bolus) rather than postoperatively. It involves truncal rigidity that makes ventilation difficult, but it wouldn't present as generalized flaccid-like weakness in the recovery room. **Clinical Pearls for NEET-PG:** * **Gold Standard Monitoring:** Train-of-Four (TOF) monitoring. A **TOF ratio > 0.9** is required for safe extubation. * **Clinical Tests for Recovery:** Sustained head lift for 5 seconds, strong hand grip, and effective cough. * **Reversal Agents:** Neostigmine (acetylcholinesterase inhibitor) or **Sugammadex** (specific reversal for Rocuronium/Vecuronium). * **Dual Block:** Seen with Phase II block of Succinylcholine; treated similarly to non-depolarizing block.

Question 26: Which of the following drugs is believed to be effective in the treatment of post-operative shivering?

A. Ondansetron
B. Diclofenac Sodium
C. Pethidine (Correct Answer)
D. Paracetamol

Explanation: **Explanation:** **Postoperative Shivering (POS)** is a common complication following general or spinal anesthesia, occurring in up to 40% of patients. It increases oxygen consumption, CO2 production, and cardiac output, making its management crucial. **Why Pethidine (Meperidine) is the Correct Answer:** Pethidine is considered the **gold standard** and the most effective drug for treating postoperative shivering. Unlike other opioids, pethidine acts on **kappa (κ) receptors** in addition to mu (μ) receptors. Its unique efficacy stems from its ability to significantly **lower the shivering threshold** (the core temperature at which the body initiates shivering) more effectively than any other drug. A low dose (10–25 mg IV) usually provides rapid relief. **Analysis of Incorrect Options:** * **Ondansetron (A):** While some studies suggest 5-HT3 antagonists may have a prophylactic role in preventing shivering by modulating central temperature regulation, they are not the primary treatment of choice compared to pethidine. * **Diclofenac Sodium (B) & Paracetamol (D):** These are Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and non-opioid analgesics. While excellent for postoperative pain management, they do not act on the thermoregulatory center in the hypothalamus to suppress the shivering reflex. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism of POS:** Primarily due to intraoperative core hypothermia and the effects of volatile anesthetics on the hypothalamus. * **Other drugs used:** Tramadol, Clonidine, and Dexmedetomidine are also used, but Pethidine remains the most classic answer. * **Non-pharmacological management:** Forced-air warming blankets (Bair Hugger) are the most effective preventive measure. * **Pethidine Side Effect:** Be cautious of its metabolite, **normeperidine**, which can lower the seizure threshold (especially in renal failure).

Question 27: Shivering is observed in the early postoperative period. What is the cause?

A. Chloroform
B. Halothane (Correct Answer)
C. Trichloroethylene
D. Ether

Explanation: **Explanation:** Postoperative shivering (POS) is a common complication following general anesthesia, and **Halothane** is classically associated with this phenomenon. **Why Halothane is the Correct Answer:** Halothane, a potent volatile anesthetic, causes significant peripheral vasodilation and depression of the hypothalamic thermoregulatory center. This leads to a rapid drop in core body temperature (hypothermia). As the patient emerges from anesthesia, the thermoregulatory center regains function and detects the low core temperature, triggering a compensatory shivering response to generate heat. Additionally, Halothane is known to increase muscle sensitivity to cold, further predisposing the patient to "Halothane shakes." **Analysis of Incorrect Options:** * **Chloroform:** While it is a potent anesthetic, it is largely obsolete due to severe hepatotoxicity and arrhythmogenic potential. It is not the primary agent associated with the specific clinical presentation of postoperative shivering in modern literature. * **Trichloroethylene (Trilene):** Used historically for analgesia (e.g., in obstetrics), it is rarely used now due to its reaction with soda lime (forming toxic phosgene) and is not a classic cause of POS. * **Ether:** Diethyl ether is a sympathetic stimulant. While it can cause postoperative nausea and vomiting (PONV), it does not typically cause the profound thermoregulatory depression seen with Halothane. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** POS is primarily a thermoregulatory response to core hypothermia, though non-thermoregulatory factors (pain, alkalosis) may contribute. * **Drug of Choice:** **Pethidine (Meperidine)** is the gold standard treatment for postoperative shivering (dose: 10–25 mg IV). It acts on κ-opioid receptors to lower the shivering threshold. * **Other Agents:** Clonidine, Tramadol, and Dexmedetomidine are also effective in managing POS. * **Complications:** Shivering is detrimental because it increases oxygen consumption by up to 200–500%, which can trigger myocardial ischemia in high-risk patients.

Question 28: After successful resuscitation and achieving stable spontaneous circulation, what is the next appropriate step?

A. Measure blood glucose
B. Assess central nervous system involvement (Correct Answer)
C. Evaluate spontaneous respiratory effort
D. Assess volume status

Explanation: **Explanation:** The primary goal immediately following **Return of Spontaneous Circulation (ROSC)** is the optimization of post-cardiac arrest care to improve neurological outcomes. **Why Option B is Correct:** The brain is the organ most sensitive to ischemia. Once hemodynamics are stabilized (ROSC), the immediate priority is to **assess the Central Nervous System (CNS)**. This involves evaluating the patient's level of consciousness and pupillary reflexes. If the patient is not following commands (comatose), **Targeted Temperature Management (TTM)**—formerly known as therapeutic hypothermia—must be initiated. TTM is a high-yield intervention that reduces cerebral metabolic rate and prevents secondary brain injury, significantly improving survival and functional recovery. **Why Other Options are Incorrect:** * **Option A (Blood Glucose):** While hyperglycemia is common post-arrest and should be managed, it is a secondary metabolic concern, not the immediate priority after achieving stability. * **Option C (Respiratory Effort):** Most patients post-ROSC require mechanical ventilation to optimize oxygenation ($PaO_2$ 75–100 mmHg) and capnography ($EtCO_2$ 35–45 mmHg). Assessing spontaneous effort is part of ongoing care but follows the initial neurological triage for TTM. * **Option D (Volume Status):** Volume status is typically addressed *during* the resuscitation phase to achieve ROSC. Once circulation is "stable" (as per the question), the focus shifts from hemodynamics to neuroprotection. **High-Yield Clinical Pearls for NEET-PG:** * **TTM Goal:** Maintain a constant temperature between **32°C and 36°C** for at least 24 hours. * **Post-ROSC Oxygenation:** Avoid hyperoxia; maintain $SpO_2$ between **92-98%**. * **Hemodynamic Target:** Maintain Mean Arterial Pressure (MAP) **>65 mmHg**. * **Gold Standard:** A 12-lead ECG should be obtained immediately post-ROSC to rule out ST-elevation myocardial infarction (STEMI).

Question 29: A risk score for predicting postoperative nausea and vomiting after inhalational anesthesia comprises all of the following factors except?

A. Female gender
B. Prior history of motion sickness
C. Non-smoking status
D. Obesity (Correct Answer)

Explanation: The question refers to the **Apfel Simplified Risk Score**, which is the gold standard for predicting Postoperative Nausea and Vomiting (PONV) in adults undergoing inhalational anesthesia. ### **Explanation of the Correct Answer** **D. Obesity:** While intuitively linked to many surgical complications, multiple large-scale clinical trials have demonstrated that **Obesity (BMI > 30 kg/m²)** is **not** an independent risk factor for PONV. Therefore, it is not included in the Apfel scoring system. ### **Analysis of Incorrect Options** The Apfel score consists of four independent predictors, each assigned 1 point. The options below are the established risk factors: * **A. Female Gender:** Women are approximately 3 times more likely to suffer from PONV than men (likely due to hormonal influences). * **B. Prior History of PONV or Motion Sickness:** Patients with a sensitive "vomiting center" or vestibular system have a significantly higher baseline risk. * **C. Non-smoking Status:** Interestingly, smoking appears to have a protective effect against PONV (potentially due to enzyme induction or desensitization of nicotinic receptors). Thus, being a **non-smoker** is a risk factor. * *(Note: The fourth factor not listed in the options is the use of **Postoperative Opioids**).* ### **Clinical Pearls for NEET-PG** * **Apfel Score Interpretation:** * 0 factors: 10% risk * 1 factor: 21% risk * 2 factors: 39% risk * 3 factors: 61% risk * 4 factors: 79% risk * **Pediatric Equivalent:** The **Zeev-Pohl Score** is used for children (factors include: surgery duration >30 mins, age >3 years, strabismus surgery, and history of PONV). * **Emetogenic Anesthetics:** Nitrous oxide and volatile inhalational agents (Isoflurane, Sevoflurane) are major triggers; **Propofol** is the only anesthetic with anti-emetic properties. * **Surgery Type:** Laparoscopic, gynecological, and strabismus surgeries carry the highest PONV risk.

Question 30: Which of the following complications is most likely to occur after receiving several units of blood transfusion?

A. Metabolic alkalosis (Correct Answer)
B. Metabolic acidosis
C. Respiratory alkalosis
D. Respiratory acidosis

Explanation: **Explanation:** The correct answer is **Metabolic Alkalosis**. This occurs primarily due to the metabolism of **sodium citrate**, which is used as an anticoagulant in stored blood bags. 1. **Mechanism of Correct Answer:** Each unit of whole blood or packed red blood cells contains a significant amount of citrate. Once transfused, the liver metabolizes citrate into **bicarbonate (HCO₃⁻)**. In massive transfusions (typically defined as >10 units in 24 hours or >4 units in 1 hour), the sudden load of bicarbonate exceeds the kidney's excretory capacity, leading to an increase in blood pH and metabolic alkalosis. 2. **Why Incorrect Options are Wrong:** * **Metabolic Acidosis:** While stored blood is slightly acidic due to the accumulation of lactic acid and pyruvic acid over time, this is transient. Once transfused, the metabolic conversion of citrate to bicarbonate quickly shifts the balance toward alkalosis. Acidosis is only seen in the initial phase of a massive transfusion or in patients with severe liver failure who cannot metabolize citrate. * **Respiratory Alkalosis/Acidosis:** These are primary disorders of ventilation (CO₂ elimination). Blood transfusion does not directly affect the respiratory drive or CO₂ exchange in a way that would predictably cause these conditions as a primary metabolic consequence. **High-Yield Clinical Pearls for NEET-PG:** * **Citrate Toxicity:** Rapid transfusion can lead to hypocalcemia because citrate chelates ionized calcium. Always monitor for signs like prolonged QT interval or tetany. * **Potassium Shift:** Stored blood contains high extracellular potassium (due to RBC lysis). However, post-transfusion, as the cells become active and the alkalosis persists, **hypokalemia** is more common than hyperkalemia. * **Hypothermia:** Transfusing cold blood can shift the oxyhemoglobin dissociation curve to the left, further complicating tissue oxygen delivery.

Practice by Chapter

Post-Anesthesia Care Unit Operations

Practice Questions

Emergence and Recovery from Anesthesia

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Postoperative Respiratory Care

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Postoperative Pain Management

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Postoperative Nausea and Vomiting

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Postoperative Cognitive Dysfunction

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Fluid Management in PACU

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Temperature Management

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Discharge Criteria

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Common PACU Complications

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Fast-Track Recovery

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Postoperative Delirium

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