Postoperative Care — MCQs

Postoperative Care Indian Medical PG Practice Questions and MCQs

Question 31: Which of the following intravenous fluids should not be used in the first 24 hours after surgery?

A. 5% dextrose
B. Isotonic saline (Correct Answer)
C. Ringer's lactate
D. All of the above

Explanation: **Explanation:** The correct answer is **Isotonic Saline (0.9% NaCl)**. **Why Isotonic Saline is avoided in the first 24 hours:** The immediate postoperative period is characterized by a **"Stress Response to Surgery."** This neuroendocrine response involves the release of **Antidiuretic Hormone (ADH)** and **Aldosterone**. 1. **ADH** causes water retention. 2. **Aldosterone** causes significant sodium and water retention while promoting potassium excretion. Administering Isotonic Saline (which contains 154 mEq/L of Na+) during this phase exacerbates sodium loading. Since the body is already in a "salt-saving" mode, excess saline leads to interstitial edema, pulmonary congestion, and delayed wound healing. Modern guidelines (like ERAS) prefer balanced salt solutions or restricted fluid strategies during this window. **Analysis of other options:** * **5% Dextrose:** While not used for volume replacement, it provides free water and prevents ketosis. It is often used in maintenance fluids postoperatively because the body needs water more than sodium in the first 24 hours. * **Ringer’s Lactate (RL):** RL is a balanced crystalloid with a lower sodium content (131 mEq/L) compared to Normal Saline. It is generally the fluid of choice for intraoperative and early postoperative replacement as it is more physiological. **NEET-PG High-Yield Pearls:** * **Standard Maintenance Fluid:** In the first 24 hours post-op, the body requires approximately **1.5–2 L of water** but very little sodium. * **Potassium:** Should generally **not** be added to IV fluids in the first 24 hours unless there is a documented deficit, as tissue trauma and the stress response already elevate serum potassium levels. * **Fluid of Choice for Resuscitation:** Ringer's Lactate is preferred over Normal Saline to avoid **Hyperchloremic Metabolic Acidosis.**

Question 32: Which of the following does not cause vomiting in a post-operative patient?

A. Ingested blood
B. N2O
C. Acetaminophen (Correct Answer)
D. Opioids

Explanation: **Explanation:** Postoperative Nausea and Vomiting (PONV) is a common complication influenced by patient factors, surgical type, and anesthetic agents. **Why Acetaminophen is the Correct Answer:** Acetaminophen (Paracetamol) is a non-opioid analgesic that acts primarily on the central nervous system to inhibit prostaglandin synthesis. Unlike opioids or volatile anesthetics, it has **no emetogenic potential**. In fact, its use is a key component of "Opioid-Sparing Analgesia" in ERAS (Enhanced Recovery After Surgery) protocols, specifically to **reduce** the incidence of PONV by decreasing the requirement for emetogenic opioids. **Analysis of Incorrect Options:** * **Ingested Blood (Option A):** Blood is a potent gastric irritant. In surgeries involving the oropharynx (e.g., tonsillectomy or dental surgery), swallowed blood triggers the chemoreceptors in the stomach, leading to postoperative vomiting. * **Nitrous Oxide (N2O) (Option B):** N2O is known to increase PONV through multiple mechanisms: middle ear pressure changes, sympathetic stimulation, and activation of the dopaminergic system in the CTZ (Chemoreceptor Trigger Zone). * **Opioids (Option D):** Opioids are a leading cause of PONV. They directly stimulate the CTZ in the area postrema of the medulla, increase vestibular sensitivity, and delay gastric emptying. **High-Yield Clinical Pearls for NEET-PG:** 1. **Apfel Score:** The most validated tool to predict PONV risk. Factors include: Female gender, Non-smoker status, History of PONV/Motion sickness, and Postoperative opioid use. 2. **Emetogenic Anesthetics:** Volatile inhalational agents (Isoflurane, Sevoflurane) and N2O are highly emetogenic. **Propofol** is the only anesthetic with significant **anti-emetic** properties. 3. **Gold Standard Prophylaxis:** 5-HT3 receptor antagonists (e.g., Ondansetron) are the first-line treatment for PONV.

Question 33: What is the most potent antiemetic agent used in the preoperative period?

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

Explanation: **Explanation:** **Metoclopramide** is the correct answer because it is a potent **prokinetic and antiemetic** agent. It acts via a dual mechanism: centrally, it blocks dopamine ($D_2$) receptors in the Chemoreceptor Trigger Zone (CTZ), and peripherally, it increases lower esophageal sphincter tone and promotes gastric emptying. In the preoperative period, it is specifically used to reduce gastric volume and prevent Mendelson’s syndrome (aspiration pneumonitis), making it the most effective choice among the options for managing perioperative nausea and vomiting (PONV). **Analysis of Incorrect Options:** * **Glycopyrrolate:** An anticholinergic used primarily as an antisialogogue (to reduce secretions) and to prevent bradycardia. It does not cross the blood-brain barrier and has no significant antiemetic properties. * **Hyoscine (Scopolamine):** While it has antiemetic properties (especially for motion sickness), it is primarily used in anesthesia for its sedative and amnestic effects. It is less potent than metoclopramide for general PONV prophylaxis. * **Atropine:** An anticholinergic used to treat bradycardia and reduce secretions. It actually relaxes the lower esophageal sphincter, which can theoretically increase the risk of reflux, unlike metoclopramide. **High-Yield Clinical Pearls for NEET-PG:** * **Mendelson’s Syndrome:** Aspiration of gastric contents (pH < 2.5, volume > 25ml). Metoclopramide is a key component of "aspiration prophylaxis." * **Drug of Choice for PONV:** While metoclopramide is potent, **Ondansetron** ($5-HT_3$ antagonist) is currently considered the gold standard/first-line for PONV prophylaxis in modern practice. * **Contraindication:** Metoclopramide is contraindicated in patients with intestinal obstruction or pheochromocytoma.

Question 34: A patient receiving an opioid analgesic in the labor ward requires close monitoring. Which medication should be readily available in case of an emergency?

A. Naloxone (Correct Answer)
B. Lignocaine
C. Diphenhydramine
D. Fentanyl

Explanation: **Explanation:** **1. Why Naloxone is the Correct Answer:** Naloxone is a **pure opioid antagonist** that competes with opioids at the mu (μ), kappa (κ), and delta (δ) receptors. In the labor ward, opioids (like Pethidine or Morphine) are commonly used for analgesia but carry a significant risk of **respiratory depression** in both the mother and the neonate (as opioids cross the placenta). Naloxone is the gold-standard treatment for reversing opioid-induced respiratory depression and toxicity. It has a rapid onset (1–2 minutes IV) and is essential for emergency resuscitation. **2. Analysis of Incorrect Options:** * **Lignocaine:** A local anesthetic and Class Ib anti-arrhythmic. It is used for epidurals or treating ventricular arrhythmias, not for reversing opioid effects. * **Diphenhydramine:** An antihistamine used for allergic reactions or opioid-induced pruritus (itching). While it treats a side effect, it cannot reverse life-threatening respiratory depression. * **Fentanyl:** A potent synthetic opioid agonist. Administering this would worsen opioid toxicity rather than treat it. **3. NEET-PG High-Yield Pearls:** * **Duration of Action:** Naloxone has a shorter half-life (30–60 mins) than most opioids. Therefore, **"renarcotization"** (re-sedation) can occur, necessitating repeated doses or a continuous infusion. * **Neonatal Dose:** If used for neonatal resuscitation following maternal opioid administration, the dose is typically 0.1 mg/kg. * **Opioid Withdrawal:** In opioid-dependent patients, naloxone can precipitate acute, severe withdrawal symptoms (abstinence syndrome). * **Other Antagonists:** Naltrexone (oral, long-acting, used for addiction) and Nalmefene (long-acting IV antagonist).

Question 35: Therapeutic hypothermia is of benefit in preventing neurological complications in which of the following conditions?

A. Sepsis
B. Poly-trauma
C. Cardiac arrest (Correct Answer)
D. Ischemic stroke

Explanation: **Explanation:** **Therapeutic Hypothermia (Targeted Temperature Management - TTM)** is a cornerstone in neuroprotection following **Cardiac Arrest**. The underlying medical concept is the reduction of cerebral metabolic rate for oxygen ($CMRO_2$). For every $1^\circ C$ drop in core temperature, the cerebral metabolic rate decreases by approximately 6-7%. This reduction helps mitigate secondary brain injury by decreasing excitatory neurotransmitter release (like glutamate), reducing free radical production, and stabilizing the blood-brain barrier. * **Cardiac Arrest (Correct):** Current guidelines (ILCOR/AHA) recommend TTM (32°C to 36°C) for adults who remain unresponsive after ROSC (Return of Spontaneous Circulation) from both shockable and non-shockable rhythms to improve neurological outcomes. * **Sepsis (Incorrect):** While fever management is important, induced hypothermia can impair immune function and worsen coagulopathy, potentially increasing mortality in septic patients. * **Poly-trauma (Incorrect):** Hypothermia is part of the "Lethal Triad" in trauma (along with acidosis and coagulopathy). It inhibits the coagulation cascade, leading to increased bleeding risk. * **Ischemic Stroke (Incorrect):** While theoretically beneficial, large clinical trials have not yet established TTM as a standard of care for acute ischemic stroke due to complications like pneumonia and lack of clear mortality benefit compared to cardiac arrest. **High-Yield Pearls for NEET-PG:** * **Target Temperature:** 32°C to 36°C for at least 24 hours. * **Adverse Effects of TTM:** Shivering (increases $O_2$ consumption), "Cold Diuresis" (hypokalemia, hypomagnesemia), bradycardia, and increased risk of wound infection. * **Rewarming:** Must be slow (0.25°C to 0.5°C per hour) to prevent rebound hyperkalemia and cerebral edema.

Question 36: Which of the following is the most significant risk factor for postoperative nausea and vomiting?

A. Female gender (Correct Answer)
B. Smoking
C. Age over 60 years
D. Surgery on the breast

Explanation: **Explanation:** Postoperative Nausea and Vomiting (PONV) is a common complication affecting approximately 30% of surgical patients. The most widely accepted tool for predicting risk is the **Apfel Simplified Risk Score**, which identifies four independent predictors. **1. Why Female Gender is Correct:** Female gender is the **strongest independent risk factor** for PONV. Adult females are approximately three times more likely to experience PONV than males. This is attributed to hormonal influences, specifically the fluctuations in estrogen and progesterone levels which sensitize the chemoreceptor trigger zone (CTZ) and the vomiting center. **2. Analysis of Incorrect Options:** * **Smoking:** Interestingly, **non-smoking status** is the risk factor. Smoking actually has a protective effect against PONV, likely due to the induction of hepatic enzymes or desensitization of dopamine receptors. * **Age over 60 years:** PONV is more common in **younger adults**. The incidence actually decreases as age increases; it is relatively rare in the elderly. * **Surgery on the breast:** While certain surgeries (laparoscopic, gynecological, breast, and strabismus surgery) are associated with higher PONV rates, **patient-related factors** (like gender) are statistically more significant predictors than the type of surgery itself. **Clinical Pearls for NEET-PG:** * **Apfel Score Criteria:** 1) Female gender, 2) Non-smoker, 3) History of PONV or motion sickness, 4) Use of postoperative opioids. * **Risk Probability:** 1 factor = 20%, 2 = 40%, 3 = 60%, 4 = 80% risk. * **Gold Standard Prophylaxis:** Combination therapy (e.g., 5-HT3 antagonists like Ondansetron + Dexamethasone) is superior to monotherapy for high-risk patients. * **Anesthetic Technique:** Using Propofol for Total Intravenous Anesthesia (TIVA) significantly reduces PONV risk compared to volatile anesthetics and nitrous oxide.

Question 37: Peri-operative respiratory failure is an example of

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

Explanation: ***Type III respiratory failure*** - This is often termed **peri-operative respiratory failure**, characterized by **atelectasis**, **reduced functional residual capacity**, and abnormal gas exchange post-surgery. - It results from the effects of anesthesia, surgery, and pain on respiratory mechanics, leading to **poor lung expansion** and hypoxemia. *Type II respiratory failure* - Characterized by **hypercapnia (high PCO2)** and **hypoxemia (low PO2)**, indicating inadequate alveolar ventilation. - Common causes include conditions like **COPD exacerbations** or **neuromuscular disorders** impacting the respiratory pump. *Type I respiratory failure* - Defined by **hypoxemia (low PO2)** with normal or low PCO2, indicating a primary problem with oxygenation. - Examples include **pulmonary edema** or **pneumonia**, where gas exchange is impaired at the alveolar-capillary membrane. *Type IV respiratory failure* - This categorization refers to **shock-related respiratory failure**, where inadequate oxygen delivery to respiratory muscles leads to their failure. - It is typically seen in states of **severe circulatory collapse**, such as septic or cardiogenic shock, and is not directly related to the peri-operative period in the way Type III is.

Question 38: Emergence delirium is associated with –

A. Halothane
B. Pentothal sodium
C. Droperidol
D. Ketamine (Correct Answer)

Explanation: ***Ketamine*** - **Ketamine**, an N-methyl-D-aspartate (NMDA) receptor antagonist, is known to cause **emergent delirium** or **psychotic reactions** during recovery from anesthesia due to its dissociative properties. - This adverse effect is more common in adults and can manifest as **hallucinations**, **vivid dreams**, and **confusion**, particularly when used as a sole anesthetic agent. *Halothane* - **Halothane** is an inhalational anesthetic that was associated with relatively slow emergence, but not typically with **delirium** as a prominent feature. - Its primary concern was **hepatotoxicity** (halothane hepatitis) and **malignant hyperthermia**, rather than emergence delirium. *Pentothal sodium* - **Pentothal sodium** (thiopental) is a short-acting barbiturate used for induction of anesthesia, known for rapid onset and offset. - While it can cause some **post-operative drowsiness**, it is not primarily associated with **emergent delirium**; instead, it provides a smooth and calm recovery. *Droperidol* - **Droperidol** is an antipsychotic and antiemetic agent often used to prevent post-operative nausea and vomiting, and can cause **sedation**. - It is known to **reduce** the incidence of emergence delirium caused by other agents, rather than causing it itself.

Question 39: In the immediate post operative period the common cause of respiratory insufficiency could be because of the following, except -

A. Mild Hypovolemia (Correct Answer)
B. Residual effect of muscle relaxant
C. Overdose of narcotic analgesic
D. Myocardial infarction

Explanation: ***Mild Hypovolemia*** - While significant **hypovolemia** can lead to systemic complications, *mild hypovolemia* itself does not directly cause *respiratory insufficiency* in the immediate postoperative period without other complicating factors. - Hypovolemia primarily affects **cardiovascular stability** and tissue perfusion, not directly the mechanics or drive of respiration unless it progresses to **shock**. *Residual effect of muscle relaxant* - **Residual neuromuscular blockade** can lead to *diaphragmatic weakness* and impaired accessory muscle function, causing insufficient ventilation and respiratory distress. - This is a common cause of *postoperative respiratory insufficiency*, especially if reversal agents are inadequate or not administered. *Overdose of narcotic analgesic* - **Narcotic overdose** depresses the *respiratory drive* in the brainstem, leading to decreased respiratory rate and depth, which can result in **hypoventilation** and *respiratory insufficiency*. - This is a significant concern in the immediate postoperative period due to pain management requirements. *Myocardial infarction* - A *myocardial infarction* can lead to **cardiogenic pulmonary edema** due to impaired cardiac function, resulting in fluid accumulation in the lungs and *respiratory insufficiency*. - Postoperative myocardial infarction is a serious complication that directly impacts respiratory function through its effect on **pulmonary hemodynamics**.

Question 40: A postoperative patient with pH 7.25, MAP (mean arterial pressure) 60 mm Hg is treated with?

A. Only normal saline
B. fluid restriction
C. Fluid therapy with CVP monitoring (Correct Answer)
D. I.V. sodium bicarbonate

Explanation: ***Fluid therapy with CVP monitoring*** - The patient's **MAP of 60 mmHg** indicates **hypotension** and potential **hypovolemic shock**, while pH 7.25 suggests **acidosis**, which could be metabolic due to poor perfusion. Initial treatment should focus on **restoring circulating volume** to improve blood pressure and organ perfusion. - **Central venous pressure (CVP) monitoring** is crucial to guide fluid resuscitation. It helps assess the patient's fluid status and ensures that enough fluid is given to improve cardiac output without causing fluid overload, especially in a severely ill patient. *Only normal saline* - While normal saline is used for fluid resuscitation, simply stating "only normal saline" is insufficient because it doesn't address the **critical need for monitoring** to guide treatment. - The amount and rate of fluid administration need to be carefully controlled based on the patient's response and hemodynamic parameters. *Fluid restriction* - **Fluid restriction** would be contraindicated in this patient because the **low MAP** suggests **hypovolemia or cardiogenic shock**, requiring fluid repletion, not restriction. - Restricting fluids could further worsen hypotension and organ hypoperfusion, leading to increased acidosis and organ damage. *I.V. sodium bicarbonate* - Administering **I.V. sodium bicarbonate** to correct acidosis without addressing the underlying cause of hypotension and poor perfusion is generally not recommended. - The acidosis (pH 7.25) is likely due to **poor tissue oxygenation and lactic acid production** from inadequate blood flow; correcting this with fluids will resolve the acidosis.

Practice by Chapter

Post-Anesthesia Care Unit Operations

Practice Questions

Emergence and Recovery from Anesthesia

Practice Questions

Postoperative Respiratory Care

Practice Questions

Postoperative Pain Management

Practice Questions

Postoperative Nausea and Vomiting

Practice Questions

Postoperative Cognitive Dysfunction

Practice Questions

Fluid Management in PACU

Practice Questions

Temperature Management

Practice Questions

Discharge Criteria

Practice Questions

Common PACU Complications

Practice Questions

Fast-Track Recovery

Practice Questions

Postoperative Delirium

Practice Questions

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