Postoperative Care — MCQs
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What oxygen concentration should be supplemented in all post-operative patients?
A 35-year-old patient is given excessive intravenous Benzodiazepine. She suddenly becomes agitated, combative, and exhibits involuntary movements. The anesthesiologist determines that she is having a reaction to the drug which has been given in excess. What is the next step in management?
Peri-operative respiratory failure is most commonly associated with which type?
A newborn developed respiratory depression in a postoperative ward. Which of the following medications can cause this side effect?
Which of the following solutions is a colloid?
Which of the following plasma expanders, similar to albumin with a molecular weight of 30,000, causes fewer hypersensitivity reactions but should be used with caution?
Which of the following is consistent with return of muscle tone adequate to protect the airway from aspiration after reversal from anesthesia?
Which of the following is not considered an ideal method for postoperative analgesia?
What is a cause of postoperative hypertension?
Three weeks after surgery to implant a mechanical aortic valve, a 70-year-old man develops chest pain, fever, and leukocytosis. On examination, the JVP is increased, there is a mechanical S2 sound, and a pericardial friction rub. Which of the following is the most likely diagnosis?
Postoperative Care Indian Medical PG Practice Questions and MCQs
Question 1: What oxygen concentration should be supplemented in all post-operative patients?
- A. 50-60%
- B. 40-45%
- C. 30-35% (Correct Answer)
- D. 20-25%
Explanation: **Explanation:** In the immediate postoperative period, patients are at high risk for **postoperative hypoxemia** due to several factors: residual effects of anesthetic agents (causing respiratory depression), splinting due to pain, and ventilation-perfusion (V/Q) mismatch caused by atelectasis. **Why 30-35% is the Correct Answer:** Standard practice in the Post-Anesthesia Care Unit (PACU) is to provide supplemental oxygen to maintain an arterial oxygen saturation ($SaO_2$) above 94%. An inspired oxygen concentration ($FiO_2$) of **30-35%** is generally sufficient to prevent hypoxemia in most healthy patients without causing complications. This is typically achieved using a simple face mask (5-6 L/min) or nasal prongs (2-4 L/min). **Analysis of Incorrect Options:** * **A & B (40-60%):** These concentrations are unnecessarily high for routine cases. High $FiO_2$ levels can lead to **absorption atelectasis** (where high oxygen replaces nitrogen in the alveoli, causing them to collapse) and can mask hypoventilation by maintaining saturation despite rising $CO_2$ levels. * **D (20-25%):** Room air is 21%. Providing only 20-25% oxygen offers little to no margin of safety against the physiological shunts and decreased Functional Residual Capacity (FRC) common after surgery. **High-Yield Clinical Pearls for NEET-PG:** * **Diffusion Hypoxia:** Specifically seen after Nitrous Oxide ($N_2O$) use; $N_2O$ rushes out of the blood into the alveoli, diluting oxygen. This is prevented by giving **100% $O_2$ for 5-10 minutes** at the end of surgery. * **Target Saturation:** In patients with COPD or chronic hypercapnia, the target $SaO_2$ is lower (88-92%) to avoid suppressing the hypoxic respiratory drive. * **Most common cause of early post-op hypoxemia:** Atelectasis and decreased FRC.
Question 2: A 35-year-old patient is given excessive intravenous Benzodiazepine. She suddenly becomes agitated, combative, and exhibits involuntary movements. The anesthesiologist determines that she is having a reaction to the drug which has been given in excess. What is the next step in management?
- A. Protamine
- B. Flumazenil (Correct Answer)
- C. Buprenorphine
- D. Morphine
Explanation: ### Explanation **Correct Answer: B. Flumazenil** **Mechanism and Rationale:** The patient is experiencing a **paradoxical reaction** to benzodiazepines (BZDs). While BZDs are typically used for sedation and anxiolysis, excessive doses or specific patient factors can trigger agitation, combativeness, and involuntary movements. **Flumazenil** is a specific **competitive antagonist** at the benzodiazepine receptor site on the GABA-A receptor complex. It rapidly reverses both the sedative effects and the paradoxical reactions caused by BZDs. In clinical practice, it is the "gold standard" antidote for BZD overdose or to reverse deep sedation postoperatively. **Analysis of Incorrect Options:** * **A. Protamine:** This is the specific antagonist used to reverse the anticoagulant effects of **Heparin**. It has no role in managing sedative toxicity. * **C. Buprenorphine:** A partial opioid agonist-antagonist used primarily for pain management or opioid de-addiction. It would not reverse BZD-induced symptoms. * **D. Morphine:** An opioid agonist. Giving morphine to an already agitated or over-sedated patient could worsen respiratory depression and complicate the clinical picture. **High-Yield Clinical Pearls for NEET-PG:** * **Half-life Caution:** Flumazenil has a shorter half-life (approx. 1 hour) than most benzodiazepines (e.g., Diazepam). **Resedation** can occur, so the patient must be monitored closely for several hours. * **Contraindication:** Avoid Flumazenil in patients with a history of **seizures** or those on long-term BZDs, as it can precipitate acute withdrawal seizures. * **Dosage:** The initial recommended dose is 0.2 mg IV over 15 seconds, repeated as necessary up to 1 mg. * **Paradoxical Reactions:** These are more common in pediatric and geriatric populations, or those with psychiatric comorbidities.
Question 3: Peri-operative respiratory failure is most commonly associated with which type?
- A. Type 1
- B. Type 2
- C. Type 3 (Correct Answer)
- D. Type 4
Explanation: **Explanation:** Respiratory failure is classified into four types based on the underlying pathophysiology. In the peri-operative setting, **Type 3 Respiratory Failure** is the most characteristic and common form. **Why Type 3 is Correct:** Type 3 respiratory failure is specifically defined as **Peri-operative Respiratory Failure**. It is primarily caused by **atelectasis** (collapse of alveoli). During surgery, factors such as general anesthesia, use of muscle relaxants, upper abdominal incisions, and pain lead to a decrease in Functional Residual Capacity (FRC). This causes the small airways to close, especially in dependent lung zones, leading to ventilation-perfusion (V/Q) mismatch and hypoxemia. **Analysis of Incorrect Options:** * **Type 1 (Hypoxemic):** Characterized by $PaO_2 < 60$ mmHg with normal or low $PaCO_2$. It is seen in conditions like pneumonia or pulmonary edema. While it can occur post-operatively, it is not the specific "peri-operative" classification. * **Type 2 (Hypercapnic/Ventilatory):** Characterized by $PaCO_2 > 45$ mmHg. It is caused by pump failure (e.g., COPD, neuromuscular disorders, or opioid overdose). * **Type 4 (Shock):** This occurs in patients who are intubated and ventilated during the resuscitation of shock (hypovolemic, septic, or cardiogenic) to reduce the metabolic demand of breathing muscles. **High-Yield Clinical Pearls for NEET-PG:** * **Management of Type 3:** Best managed with incentive spirometry, early mobilization, adequate analgesia (to prevent splinting), and PEEP (Positive End-Expiratory Pressure). * **Risk Factors:** Upper abdominal and thoracic surgeries carry the highest risk due to diaphragmatic dysfunction. * **Key Distinction:** Remember the "Rule of 4": Type 1 (Oxygenation), Type 2 (Ventilation), Type 3 (Atelectasis/Peri-operative), Type 4 (Shock/Hypoperfusion).
Question 4: A newborn developed respiratory depression in a postoperative ward. Which of the following medications can cause this side effect?
- A. Opioid (Correct Answer)
- B. Propofol
- C. Furosemide
- D. Heparin
Explanation: **Explanation:** **1. Why Opioids are the Correct Answer:** Opioids (such as morphine or fentanyl) are potent analgesics commonly used for postoperative pain management. However, they are notorious for causing **dose-dependent respiratory depression** by acting on **μ-receptors** in the medullary respiratory centers. This action decreases the sensitivity of the brainstem to carbon dioxide (CO₂). Newborns are particularly vulnerable due to an immature blood-brain barrier, reduced metabolic clearance, and a higher sensitivity of their respiratory centers to opioid-induced depression. **2. Why Other Options are Incorrect:** * **Propofol:** While propofol is a potent intravenous anesthetic that causes respiratory depression and apnea, it is used for the **induction and maintenance** of anesthesia. It has an extremely short half-life (minutes); therefore, it is unlikely to be the primary cause of delayed respiratory depression in a postoperative ward setting once the patient has emerged. * **Furosemide:** This is a loop diuretic used to treat fluid overload or heart failure. Its primary side effects are electrolyte imbalances (hypokalemia) and dehydration, not direct respiratory center depression. * **Heparin:** This is an anticoagulant used to prevent thromboembolism. Its main complication is hemorrhage; it has no effect on the respiratory drive. **Clinical Pearls for NEET-PG:** * **Antidote:** The specific antagonist for opioid-induced respiratory depression is **Naloxone** (dose: 0.01 mg/kg in neonates). * **Neonatal Physiology:** Newborns have a higher chest wall compliance and lower functional residual capacity (FRC), making them desaturate faster during periods of hypoventilation. * **Monitoring:** The earliest sign of opioid toxicity in a postoperative ward is often a **decreased respiratory rate (bradypnea)** and sedation.
Question 5: Which of the following solutions is a colloid?
- A. Normal saline
- B. Albumin (Correct Answer)
- C. Ringer lactate
- D. Dextrose 5%
Explanation: **Explanation:** Intravenous fluids are broadly classified into two categories based on their molecular size and behavior in the vascular compartment: **Crystalloids** and **Colloids**. **Why Albumin is the Correct Answer:** Albumin is a natural **colloid**. Colloids contain large, high-molecular-weight particles (proteins or polymers) that do not easily cross the semi-permeable capillary membrane. Because these molecules remain in the intravascular space, they exert **oncotic pressure**, effectively drawing fluid into and maintaining volume within the blood vessels. Albumin (available in 5% or 25% concentrations) is the gold standard natural colloid used for rapid volume expansion. **Analysis of Incorrect Options:** * **Normal Saline (0.9% NaCl):** An isotonic **crystalloid**. It contains small electrolytes that freely cross capillary membranes. Only about 25% of the infused volume remains intravascularly after 30–60 minutes. * **Ringer Lactate (RL):** A balanced salt **crystalloid**. It is the fluid of choice for most surgical patients and trauma, but like saline, it redistributes into the interstitial space. * **Dextrose 5% (D5W):** A hypotonic **crystalloid**. Once the glucose is metabolized, it becomes "free water," distributing across all body compartments (including intracellularly), making it poor for volume resuscitation. **High-Yield Clinical Pearls for NEET-PG:** * **Colloid vs. Crystalloid Ratio:** To achieve the same intravascular volume expansion, you need roughly **3 to 4 times** the volume of crystalloids compared to colloids. * **Synthetic Colloids:** These include Hydroxyethyl Starches (HES), Gelatins, and Dextrans. Note that HES is now restricted due to risks of acute kidney injury (AKI) and coagulopathy. * **Indication:** Colloids are preferred when rapid volume expansion is needed with minimal interstitial edema (e.g., severe hemorrhage or hypoalbuminemia).
Question 6: Which of the following plasma expanders, similar to albumin with a molecular weight of 30,000, causes fewer hypersensitivity reactions but should be used with caution?
- A. Hydroxy ethyl starch (HES)
- B. Dextran
- C. Polygeline (Correct Answer)
- D. Polypyrrolidone
Explanation: **Explanation:** **Polygeline** (commercially known as Haemaccel) is a synthetic colloid derived from degraded bovine gelatin. It has an average molecular weight of approximately **30,000 Daltons**, which is similar to the effective oncotic pressure exerted by albumin. It is widely used as a plasma expander because it is iso-oncotic and does not interfere with cross-matching. While it is generally safer than older colloids, it must be used with caution because it can trigger **histamine release**, leading to flushing, urticaria, or hypotension (though true anaphylaxis is rarer than with Dextrans). **Analysis of Other Options:** * **Hydroxyethyl Starch (HES):** These are larger molecules (MW 130,000–450,000). While effective for volume expansion, they are associated with significant risks of **nephrotoxicity** and coagulopathy. * **Dextran:** These are glucose polymers. Dextran 70 and Dextran 40 are notorious for causing **severe anaphylactoid reactions** (due to pre-formed antibodies) and interfering with blood grouping/cross-matching. * **Polypyrrolidone (PVP):** Historically used as a plasma expander, it is now obsolete due to its tendency to be stored in the reticuloendothelial system for long periods, causing potential organ damage. **High-Yield Clinical Pearls for NEET-PG:** * **Gelatins (Polygeline):** Unique because they contain **Calcium (6.25 mmol/L)**; therefore, they should not be infused through the same line as citrated blood to avoid clotting. * **Maximum Dose:** Unlike HES, there is no strict maximum dose for gelatins, but they have a short duration of action (2–4 hours). * **Renal Safety:** Gelatins are generally considered safer for the kidneys compared to HES in critically ill patients.
Question 7: Which of the following is consistent with return of muscle tone adequate to protect the airway from aspiration after reversal from anesthesia?
- A. TOF ratio of 0.7
- B. No fade detectable on Double Burst Tetanic Stimulation
- C. Return of normal resting minute ventilation
- D. Five seconds sustained head lift (Correct Answer)
Explanation: The assessment of neuromuscular recovery is critical in anesthesia to prevent **Postoperative Residual Curarization (PORC)**, which significantly increases the risk of airway obstruction and aspiration. ### **Why Option D is Correct** The **5-second sustained head lift** is considered the "gold standard" clinical test for assessing the recovery of the pharyngeal and laryngeal muscles. These muscles are more sensitive to neuromuscular blockers than the diaphragm. A patient who can sustain a head lift for 5 seconds demonstrates sufficient strength in the accessory muscles of respiration and airway protectors to maintain patency and prevent aspiration. ### **Analysis of Incorrect Options** * **Option A (TOF ratio of 0.7):** Historically, 0.7 was the target, but modern evidence shows that a **TOF ratio of >0.9** is required to ensure the return of upper airway reflexes. At a ratio of 0.7, significant impairment of pharyngeal function and a blunted hypoxic ventilatory response still persist. * **Option B (No fade on DBS):** While Double Burst Stimulation (DBS) is more sensitive than a standard TOF for detecting manual fade, the absence of fade on DBS only correlates to a TOF ratio of approximately 0.6. This is insufficient to guarantee airway protection. * **Option C (Normal minute ventilation):** The diaphragm is the most resistant muscle to neuromuscular blockers and recovers much earlier than the pharyngeal muscles. A patient may have a normal tidal volume and minute ventilation while still being unable to protect their airway. ### **High-Yield Clinical Pearls for NEET-PG** * **Order of Muscle Recovery:** Diaphragm (First) → Intercostals → Large limb muscles → Small muscles (Hand) → Pharyngeal/Laryngeal muscles (Last). * **Most Sensitive Clinical Test:** 5-second sustained head lift or sustained leg lift. * **Most Sensitive Objective Monitor:** Quantitative TOF ratio >0.9. * **Adductor Pollicis:** The standard muscle used for peripheral nerve stimulation (Ulnar nerve). Note that recovery of the adductor pollicis lags behind the diaphragm but precedes the pharyngeal muscles.
Question 8: Which of the following is not considered an ideal method for postoperative analgesia?
- A. Patient-controlled analgesia
- B. Continuous epidural infusion with local anesthetics
- C. Intercostal nerve block
- D. Cryoanalgesia (Correct Answer)
Explanation: **Explanation:** The correct answer is **D. Cryoanalgesia**. **Why Cryoanalgesia is not ideal:** Cryoanalgesia involves the application of extreme cold (using a cryoprobe) to peripheral nerves to achieve long-term sensory blockade. While it provides prolonged pain relief, it is **not** considered an ideal method for routine postoperative analgesia due to the high risk of **permanent nerve damage** and the development of **secondary neuropathic pain** or chronic neuralgias. The destruction of the myelin sheath can lead to aberrant nerve regeneration, making it less favorable compared to reversible pharmacological methods. **Analysis of Incorrect Options:** * **A. Patient-controlled analgesia (PCA):** This is a gold standard for postoperative pain. It allows patients to self-administer small doses of opioids (usually IV), ensuring better titration, higher patient satisfaction, and avoiding the "peaks and valleys" of intermittent IM injections. * **B. Continuous epidural infusion:** This is highly effective, especially for major thoracic and abdominal surgeries. Using local anesthetics (often with opioids) provides superior analgesia, reduces the stress response to surgery, and facilitates early mobilization. * **C. Intercostal nerve block:** This is an excellent technique for postoperative pain following thoracic or upper abdominal incisions. It significantly improves respiratory mechanics by reducing splinting, though it carries a small risk of pneumothorax. **High-Yield Clinical Pearls for NEET-PG:** * **Multimodal Analgesia:** The current "best practice" which combines different classes of analgesics (NSAIDs, Paracetamol, Opioids, and Regional blocks) to minimize side effects. * **PCA Safety:** The most important safety feature of a PCA pump is the **"Lock-out interval,"** which prevents accidental overdose. * **Epidural Analgesia:** It is the most effective method for reducing postoperative pulmonary complications in high-risk patients.
Question 9: What is a cause of postoperative hypertension?
- A. Pre-operative hypertension
- B. Inadequate analgesia
- C. Phaeochromocytoma
- D. All of the above (Correct Answer)
Explanation: Postoperative hypertension is a common clinical scenario defined as a 20% or greater increase in blood pressure compared to baseline. It typically occurs within the first two hours of recovery and is primarily driven by **sympathetic nervous system overactivity**. **Explanation of Options:** * **Pre-operative hypertension (Option A):** This is the single most significant predictor of postoperative hypertension. Patients with poorly controlled baseline BP have an exaggerated sympathetic response to surgical stress and intubation, leading to labile hemodynamics. * **Inadequate analgesia (Option B):** Pain is the most common reversible cause. Acute pain triggers the release of catecholamines (epinephrine and norepinephrine) and activates the renin-angiotensin-aldosterone system (RAAS), resulting in tachycardia and peripheral vasoconstriction. * **Phaeochromocytoma (Option C):** While rare, this catecholamine-secreting tumor can cause life-threatening hypertensive crises postoperatively, especially if triggered by surgical stress, certain anesthetic agents, or tumor manipulation. **Why "All of the above" is correct:** Postoperative hypertension is multifactorial. Other common triggers include hypercarbia (CO2 retention), hypoxia, bladder distension (autonomic reflex), and emergence delirium. Since all listed options independently contribute to elevated blood pressure, "All of the above" is the correct choice. **High-Yield Clinical Pearls for NEET-PG:** * **First-line management:** Always rule out and treat "reversible causes" first (e.g., provide analgesia, empty the bladder, or provide oxygen). * **Pharmacotherapy:** If BP remains high despite addressing triggers, **Labetalol** (alpha and beta-blocker) or **Esmolol** (short-acting beta-blocker) are often preferred for rapid control. * **Risk:** Uncontrolled postoperative hypertension can lead to myocardial ischemia, surgical site bleeding (hematoma), or cerebrovascular accidents (stroke).
Question 10: Three weeks after surgery to implant a mechanical aortic valve, a 70-year-old man develops chest pain, fever, and leukocytosis. On examination, the JVP is increased, there is a mechanical S2 sound, and a pericardial friction rub. Which of the following is the most likely diagnosis?
- A. Infection in the aortic valve
- B. Post pericardiotomy syndrome (Correct Answer)
- C. Cytomegalovirus (CMV) infection
- D. Pulmonary embolism
Explanation: **Explanation:** The clinical presentation of fever, chest pain, leukocytosis, and a pericardial friction rub occurring 1–6 weeks after cardiac surgery is classic for **Post-pericardiotomy Syndrome (PPS)**. **1. Why Post-pericardiotomy Syndrome is Correct:** PPS is an immune-mediated pleuropericarditis triggered by damage to the pericardium and the presence of blood in the pericardial space. The 3-week timeline is the "sweet spot" for this delayed hypersensitivity reaction. Key diagnostic features seen in this patient include: * **Pericardial Friction Rub:** Pathognomonic for pericarditis. * **Increased JVP:** Suggests pericardial effusion or tamponade physiology. * **Systemic Inflammation:** Fever and leukocytosis. **2. Why Other Options are Incorrect:** * **Infection in the aortic valve (Endocarditis):** While fever and leukocytosis occur, the presence of a **mechanical S2** indicates the valve is functioning normally. Endocarditis usually presents with a new murmur (regurgitation) rather than a friction rub. * **CMV Infection:** Known as "Post-perfusion syndrome" (due to bypass/transfusions), it presents with fever and atypical lymphocytosis but does not cause a pericardial friction rub or signs of pericarditis. * **Pulmonary Embolism:** While it causes chest pain and tachycardia, it would not typically cause a pericardial friction rub or a high-grade fever 3 weeks post-op without other localizing signs. **Clinical Pearls for NEET-PG:** * **Treatment:** The first-line treatment for PPS is **NSAIDs (Aspirin)** and **Colchicine**. Steroids are reserved for refractory cases. * **Triad of PPS:** Fever, pleuritic chest pain, and pericardial/pleural effusion. * **Differentiation:** Unlike early postoperative pericarditis (which occurs within 48–72 hours due to surgical trauma), PPS is a delayed immunological phenomenon.
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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