Pre-operative evaluation — MCQs

Q: A 45-year-old woman on warfarin for mechanical mitral valve replacement (INR therapeutic at 2.8) presents with acute cholecystitis requiring surgery within 24 hours. She has no history of thromboembolism beyond the indication for her valve. Apply the appropriate perioperative anticoagulation management.

Stop warfarin, bridge with therapeutic heparin, operate when INR <1.5. ***Stop warfarin, bridge with therapeutic heparin, operate when INR <1.5*** - Patients with a **mechanical mitral valve** are considered **high-risk** for thromboembolism and require **bridging therapy** with heparin when warfarin is discontinued. - For surgery within 24 hours, **IV unfractionated heparin** is preferred over LMWH because it can be stopped 4-6 hours before the procedure and reversed quickly if needed. *Stop warfarin and proceed when INR <1.5* - This approach is inappropriate for **high-risk** patients as it leaves them unprotected from **thromboembolic events** for several days while the INR drops. - A **mechanical mitral valve** has a higher thrombogenicity than an aortic valve, necessitating active bridging during the perioperative window. *Give vitamin K, fresh frozen plasma, and proceed emergently* - This is reserved for **life-threatening bleeding** or true **emergent surgeries** (within minutes to hours) where there is no time for heparin bridging. - **Acute cholecystitis** mentioned as requiring surgery within 24 hours is classified as **urgent**, not emergent, allowing time for a more controlled heparin bridge. *Continue warfarin and accept increased bleeding risk* - Operating with an **INR of 2.8** carries a significant and unacceptable risk of **intraoperative hemorrhage** for abdominal surgery. - Standard surgical practice requires an **INR <1.5** to ensure adequate **hemostasis** and safety during dissection and cautery. *Stop warfarin, bridge with low-molecular-weight heparin, proceed in 12 hours* - **LMWH** has a longer half-life than unfractionated heparin, making it less ideal for surgery planned within a **24-hour window** where flexibility is needed. - Proceeding in 12 hours is often insufficient for the **INR to normalize** naturally from a therapeutic level of 2.8 without reversal agents.

Q: A 72-year-old man with type 2 diabetes on metformin and glipizide is scheduled for coronary artery bypass grafting in 3 days. His HbA1c is 8.2%, fasting glucose is 185 mg/dL, and creatinine is 1.8 mg/dL. He will require contrast angiography the day before surgery. Apply the appropriate perioperative glycemic management.

Stop both oral agents and start insulin 48 hours before contrast. ***Stop both oral agents and start insulin 48 hours before contrast*** - **Metformin** must be discontinued 48 hours prior to contrast administration and major surgery to prevent **lactic acidosis**, particularly in patients with **renal impairment** (Creatinine 1.8 mg/dL). - **Sulfonylureas** (glipizide) should be stopped to prevent prolonged **hypoglycemia** during the fasting (NPO) period associated with surgery and procedures. *Continue current medications until day of surgery* - Continuing **Metformin** carries a high risk of lactic acidosis if the patient develops **contrast-induced nephropathy** or perioperative renal failure. - Keeping the patient on oral agents fails to address the sub-optimal glycemic control (HbA1c 8.2%) required for high-risk **cardiac surgery**. *Stop metformin, continue glipizide, and start insulin therapy* - **Glipizide** has a significant risk of causing **hypoglycemia** when the patient is fasting for angiography and surgery; it provides no flexibility for titration. - Discontinuing only one agent while the patient is in a **hyperglycemic state** (Glucose 185 mg/dL) will not achieve the tight control necessary to reduce **surgical site infections**. *Add insulin to current regimen without stopping oral agents* - Adding **insulin** to oral agents increases the risk of unpredictable **hypoglycemic episodes** in a perioperative setting. - **Metformin** remains contraindicated in the presence of planned **iodinated contrast** and elevated creatinine levels. *Stop glipizide only and continue metformin with increased hydration* - Hydration alone does not mitigate the risk of **metformin-associated lactic acidosis** in a patient with an existing **creatinine of 1.8 mg/dL** undergoing contrast studies. - This approach ignores the standard safety guidelines which prioritize the early cessation of **biguanides** before major cardiovascular procedures.

A 66-year-old man with severe aortic stenosis (valve area 0.7 cm², mean gradient 55 mmHg) and Class III heart failure requires emergent hemicolectomy for perforated diverticulitis with peritonitis. He is hemodynamically stable on pressors. Cardiology states he is high-risk for valve replacement but could undergo TAVR in 2-3 weeks. The surgeon believes he needs surgery within 6-8 hours. Evaluate the management approach.

A 35-year-old woman scheduled for thyroidectomy for papillary thyroid cancer is found to have prolonged aPTT (52 seconds, normal 25-35) on routine preoperative labs. PT/INR is normal. She has history of two first-trimester miscarriages but denies personal bleeding history. Further testing reveals lupus anticoagulant positivity. Evaluate the perioperative hemostatic management.

A 48-year-old woman with newly diagnosed pheochromocytoma (4 cm right adrenal mass) is scheduled for laparoscopic adrenalectomy. Initial blood pressure is 180/110 mmHg with episodes of hypertension to 220/120 mmHg, headaches, and palpitations. Plasma metanephrines are markedly elevated. Evaluate the optimal preoperative preparation timeline and management.

A 70-year-old woman presents for preoperative evaluation before elective abdominal aortic aneurysm repair (5.8 cm). She has no cardiac symptoms but has diabetes, hypertension, and peripheral vascular disease. Her functional capacity is limited by arthritis - she walks only 50 feet before stopping due to joint pain, not dyspnea or chest discomfort. Analyze the appropriate cardiac risk stratification strategy.

A 58-year-old man with Child-Pugh class B cirrhosis (score 8) due to hepatitis C presents with symptomatic inguinal hernia. He has mild ascites controlled with diuretics, no encephalopathy, albumin 2.9 g/dL, bilirubin 2.4 mg/dL, and INR 1.6. He requests surgical repair. Analyze the perioperative risk and management approach.

A 62-year-old man scheduled for elective total hip replacement has a hemoglobin of 9.5 g/dL (baseline 14 g/dL). Workup reveals MCV 72 fL, ferritin 15 ng/mL, and positive fecal occult blood test. He denies any GI symptoms. Colonoscopy 5 years ago was normal. Analyze the most appropriate preoperative approach.

A 45-year-old woman on warfarin for mechanical mitral valve replacement (INR therapeutic at 2.8) presents with acute cholecystitis requiring surgery within 24 hours. She has no history of thromboembolism beyond the indication for her valve. Apply the appropriate perioperative anticoagulation management.

A 72-year-old man with type 2 diabetes on metformin and glipizide is scheduled for coronary artery bypass grafting in 3 days. His HbA1c is 8.2%, fasting glucose is 185 mg/dL, and creatinine is 1.8 mg/dL. He will require contrast angiography the day before surgery. Apply the appropriate perioperative glycemic management.

A 55-year-old woman with chronic obstructive pulmonary disease (FEV1 45% predicted) requires elective cholecystectomy for symptomatic cholelithiasis. She uses home oxygen at 2 L/min and has had two hospitalizations for COPD exacerbations in the past year. She smokes half a pack of cigarettes daily. Apply the most appropriate preoperative pulmonary optimization strategy.

Q10

A 68-year-old man with a history of myocardial infarction 4 months ago is scheduled for elective inguinal hernia repair. He reports mild chest discomfort with climbing two flights of stairs but denies rest symptoms. His medications include aspirin, metoprolol, and atorvastatin. ECG shows Q waves in leads II, III, and aVF. Apply the appropriate preoperative cardiac risk stratification for this patient.

Pre-operative evaluation US Medical PG Practice Questions and MCQs

Question 1: A 66-year-old man with severe aortic stenosis (valve area 0.7 cm², mean gradient 55 mmHg) and Class III heart failure requires emergent hemicolectomy for perforated diverticulitis with peritonitis. He is hemodynamically stable on pressors. Cardiology states he is high-risk for valve replacement but could undergo TAVR in 2-3 weeks. The surgeon believes he needs surgery within 6-8 hours. Evaluate the management approach.

A. Delay surgery, perform urgent TAVR, then colectomy in 2-3 weeks
B. Proceed with colectomy under invasive monitoring with cardiology backup (Correct Answer)
C. Perform colostomy only under local anesthesia, defer resection
D. Medical management of perforation with antibiotics pending TAVR
E. Simultaneous TAVR and emergency colectomy in hybrid OR

Explanation: ***Proceed with colectomy under invasive monitoring with cardiology backup*** - Perforated diverticulitis with **peritonitis** is an immediate surgical emergency requiring intervention within hours to prevent **sepsis** and death. - Management of **severe aortic stenosis** in non-cardiac emergencies involves **invasive hemodynamic monitoring** to maintain a fixed cardiac output, adequate **preload**, and stable **systemic vascular resistance**. *Delay surgery, perform urgent TAVR, then colectomy in 2-3 weeks* - Waiting 2-3 weeks for a **TAVR** is not feasible for a patient with **peritonitis**, as the risk of mortality from untreated perforation is nearly 100%. - **TAVR** requires a recovery period and often **antiplatelet therapy**, which would further complicate and delay the necessary abdominal surgery. *Perform colostomy only under local anesthesia, defer resection* - **Local anesthesia** is insufficient for managing generalized **peritonitis** and would not allow for the necessary thorough abdominal washout and source control. - A simple colostomy without **resection** of the perforated segment fails to eliminate the source of **fecal contamination**, leading to persistent sepsis. *Medical management of perforation with antibiotics pending TAVR* - Antibiotics alone are inadequate for **Hinchey III/IV peritonitis**; the lack of **source control** results in high mortality regardless of cardiac status. - The patient is already on **pressors**, indicating that the septic process is advanced and requires mechanical/surgical correction rather than conservative medical therapy. *Simultaneous TAVR and emergency colectomy in hybrid OR* - Combining a **clean-contaminated** or dirty surgery (colectomy) with a sterile cardiac procedure (TAVR) carries an unacceptable risk of **prosthetic valve infection**. - The physiological stress of both procedures simultaneously would likely exceed the patient's **hemodynamic compensatory** mechanisms in the setting of acute sepsis.

Question 2: A 35-year-old woman scheduled for thyroidectomy for papillary thyroid cancer is found to have prolonged aPTT (52 seconds, normal 25-35) on routine preoperative labs. PT/INR is normal. She has history of two first-trimester miscarriages but denies personal bleeding history. Further testing reveals lupus anticoagulant positivity. Evaluate the perioperative hemostatic management.

A. Cancel surgery and treat with anticoagulation indefinitely
B. Proceed with surgery without additional precautions as bleeding risk is not increased (Correct Answer)
C. Administer fresh frozen plasma preoperatively to correct aPTT
D. Start therapeutic anticoagulation and bridge perioperatively
E. Delay surgery, perform comprehensive thrombophilia workup, individualize management

Explanation: ***Proceed with surgery without additional precautions as bleeding risk is not increased*** - **Lupus anticoagulant** is an in-vitro laboratory artifact that causes a **prolonged aPTT** but is actually associated with a **prothrombotic state** rather than a bleeding risk. - Since the patient has no personal history of bleeding and the **PT/INR** is normal, she can safely proceed with thyroidectomy without correction of the laboratory values. *Cancel surgery and treat with anticoagulation indefinitely* - Primary **anticoagulation** is generally reserved for patients with a history of **venous or arterial thrombosis**, not just isolated laboratory findings or miscarriages without confirmed APS diagnosis. - **Cancer surgery** should not be indefinitely delayed for an asymptomatic laboratory abnormality that does not increase operative mortality. *Administer fresh frozen plasma preoperatively to correct aPTT* - **Fresh frozen plasma (FFP)** is used to replace clotting factors, but the aPTT prolongation here is due to **antiphospholipid antibodies** interfering with the assay, not a factor deficiency. - Administering FFP will not significantly correct the **aPTT** and exposes the patient to unnecessary risks like **TRALI** or volume overload. *Start therapeutic anticoagulation and bridge perioperatively* - **Therapeutic anticoagulation** is contraindicated immediately before surgery due to the high risk of **intraoperative hemorrhage**, especially in delicate areas like the neck. - Bridging is only indicated for patients with a high-risk history of **thromboembolism** who are already on chronic anticoagulation. *Delay surgery, perform comprehensive thrombophilia workup, individualize management* - While the patient likely has **Antiphospholipid Syndrome (APS)** based on miscarriages and LA positivity, a full workup is not required to establish **hemostatic safety** for the procedure. - **Lupus anticoagulant** is already identified; further testing will not change the fact that the patient does not have a clinical **bleeding diathesis**.

Question 3: A 48-year-old woman with newly diagnosed pheochromocytoma (4 cm right adrenal mass) is scheduled for laparoscopic adrenalectomy. Initial blood pressure is 180/110 mmHg with episodes of hypertension to 220/120 mmHg, headaches, and palpitations. Plasma metanephrines are markedly elevated. Evaluate the optimal preoperative preparation timeline and management.

A. Urgent surgery within 48 hours with IV phentolamine available
B. Alpha-blockade for 7-14 days, then beta-blockade, volume expansion, then surgery (Correct Answer)
C. Beta-blockade first to control heart rate, then surgery in one week
D. Combined alpha-beta blocker (labetalol) for one week, then surgery
E. Calcium channel blocker for blood pressure control and immediate surgery

Explanation: ***Alpha-blockade for 7-14 days, then beta-blockade, volume expansion, then surgery*** - Optimal preoperative preparation requires **phenoxybenzamine** (a non-competitive alpha-blocker) for 7-14 days to stabilize blood pressure and restore **intravascular volume**. - **Beta-blockers** are only added after adequate alpha-blockade to manage tachycardia; **volume expansion** via high-salt diet/IV fluids prevents post-resection hypotension. *Urgent surgery within 48 hours with IV phentolamine available* - Urgent surgery without proper preparation carries a high risk of **intraoperative hypertensive crisis** due to catecholamine release during tumor manipulation. - **Phentolamine** is used for acute crisis management but does not replace the requirement for preoperative **long-acting alpha-blockade** to stabilize the patient. *Beta-blockade first to control heart rate, then surgery in one week* - Initiating beta-blockade first is contraindicated because it can lead to **unopposed alpha-adrenergic stimulation**, causing a severe hypertensive crisis. - Beta-blockers must only be introduced after the patient has achieved **adequate alpha-receptor blockade** to prevent peripheral vasoconstriction. *Combined alpha-beta blocker (labetalol) for one week, then surgery* - Labetalol has a much higher **beta-to-alpha blockade ratio** (approx 7:1), which can still result in worsening hypertension through **unopposed alpha-stimulation**. - Standard of care mandates selective or non-selective **alpha-blockers** as the primary agent rather than mixed agents for initial stabilization. *Calcium channel blocker for blood pressure control and immediate surgery* - While **Calcium Channel Blockers** (CCBs) can supplement blood pressure control, they are not the gold standard for blocking the systemic effects of massive **catecholamine surges**. - Immediate surgery is globally avoided in elective cases to ensure the patient is not **volume depleted**, which would lead to vascular collapse after tumor removal.

Question 4: A 70-year-old woman presents for preoperative evaluation before elective abdominal aortic aneurysm repair (5.8 cm). She has no cardiac symptoms but has diabetes, hypertension, and peripheral vascular disease. Her functional capacity is limited by arthritis - she walks only 50 feet before stopping due to joint pain, not dyspnea or chest discomfort. Analyze the appropriate cardiac risk stratification strategy.

A. Proceed directly to surgery as she has no cardiac symptoms
B. Order pharmacologic stress test due to inability to assess functional capacity (Correct Answer)
C. Obtain preoperative coronary angiography given multiple risk factors
D. Start beta-blocker therapy and proceed with surgery in one week
E. Calculate revised cardiac risk index only and proceed based on score

Explanation: ***Order pharmacologic stress test due to inability to assess functional capacity*** - For patients undergoing **high-risk surgery** (like AAA repair) with unknown/poor functional capacity (< 4 METs), **pharmacologic stress testing** is indicated if it will change management. - This patient has multiple **RCRI risk factors** (diabetes, PVD) and her arthritis prevents an assessment of exercise tolerance, making non-invasive testing necessary to evaluate for **inducible ischemia**. *Proceed directly to surgery as she has no cardiac symptoms* - While asymptomatic, the patient is undergoing a **high-risk vascular procedure** and has significant risk factors that require further stratification when functional capacity is unknown. - Asymptomatic status alone does not bypass the need for evaluation in the setting of **poor functional capacity** and clinical risk factors. *Obtain preoperative coronary angiography given multiple risk factors* - **Preoperative coronary angiography** is not a routine screening tool and is generally reserved for patients with evidence of **high-risk ischemia** on non-invasive testing. - Guidelines recommend a **stepwise approach** starting with clinical risk assessment and non-invasive stress testing before considering invasive procedures. *Start beta-blocker therapy and proceed with surgery in one week* - **Beta-blockers** should not be started acutely (within 1 week) before surgery as it may increase the risk of **bradycardia and stroke** if not appropriately titrated. - Starting medical therapy does not address the primary need to assess for **occult coronary artery disease** in a patient unable to perform physical exertion. *Calculate revised cardiac risk index only and proceed based on score* - The **Revised Cardiac Risk Index (RCRI)** is an important first step, but the algorithm requires combining that score with the patient's **functional capacity** (METs). - Simply calculating the score is insufficient here because a high score combined with **poor functional capacity** mandates further testing (e.g., stress test) before high-risk vascular surgery.

Question 5: A 58-year-old man with Child-Pugh class B cirrhosis (score 8) due to hepatitis C presents with symptomatic inguinal hernia. He has mild ascites controlled with diuretics, no encephalopathy, albumin 2.9 g/dL, bilirubin 2.4 mg/dL, and INR 1.6. He requests surgical repair. Analyze the perioperative risk and management approach.

A. Proceed with surgery after correcting INR with vitamin K
B. Delay surgery pending liver transplant evaluation
C. Optimize medical management and proceed with surgery using mesh
D. Calculate MELD score, optimize nutritionally, consider risks versus benefits (Correct Answer)
E. Refuse surgery due to prohibitive operative mortality

Explanation: ***Calculate MELD score, optimize nutritionally, consider risks versus benefits*** - For patients with **cirrhosis**, the **Model for End-Stage Liver Disease (MELD) score** is a more sensitive predictor of perioperative mortality than the **Child-Pugh classification** alone. - This patient's **low albumin** and **Child-Pugh Class B** status necessitate **nutritional optimization** and a careful evaluation of the risks of surgery versus the risk of hernia incarceration. *Proceed with surgery after correcting INR with vitamin K* - **Vitamin K** is often ineffective in correcting the **INR** in patients with advanced cirrhosis because the underlying issue is impaired **hepatic synthesis** of clotting factors, not a deficiency. - Focusing solely on **coagulation parameters** ignores the systemic risks associated with **portal hypertension** and poor liver reserve in a **Child-Pugh B** patient. *Delay surgery pending liver transplant evaluation* - While **Child-Pugh Class B** patients may eventually need a **liver transplant**, it is not an absolute requirement to delay necessary symptomatic surgery for an evaluation unless they are in **acute-on-chronic liver failure**. - The decision to transplant is based on **MELD scores** (usually >15) and complications; this patient’s priority is immediate risk stratification for his hernia. *Optimize medical management and proceed with surgery using mesh* - While medical management is important, proceeding directly to surgery without calculating the **MELD score** or weighing **mortality risks** is premature for a patient with **decompensated cirrhosis**. - **Mesh** use in patients with active **ascites** is controversial due to the high risk of **surgical site infection** and wound dehiscence. *Refuse surgery due to prohibitive operative mortality* - **Child-Pugh Class B** is associated with increased risk, but it is not a **prohibitive contraindication** (unlike Class C, which often carries a mortality risk >80%). - A symptomatic hernia requires management, as the risk of **strangulation** or **incarceration** might outweigh the risks of elective surgical repair after proper optimization.

Question 6: A 62-year-old man scheduled for elective total hip replacement has a hemoglobin of 9.5 g/dL (baseline 14 g/dL). Workup reveals MCV 72 fL, ferritin 15 ng/mL, and positive fecal occult blood test. He denies any GI symptoms. Colonoscopy 5 years ago was normal. Analyze the most appropriate preoperative approach.

A. Proceed with surgery and transfuse perioperatively as needed
B. Start oral iron supplementation and proceed with surgery in 2 weeks
C. Delay surgery, investigate GI bleeding source, correct anemia, then operate (Correct Answer)
D. Give preoperative IV iron infusion and erythropoietin, operate in 3 days
E. Transfuse 2 units PRBCs preoperatively and proceed with surgery

Explanation: ***Delay surgery, investigate GI bleeding source, correct anemia, then operate*** - The patient presents with **iron deficiency anemia** (low MCV, low ferritin) and a **positive fecal occult blood test (FOBT)**, which must be fully investigated prior to elective procedures to rule out **GI malignancy**. - Investigating the source of occult bleeding and correcting the baseline **hemoglobin** minimizes **perioperative risk** and ensures that a potentially life-threatening condition is not ignored. *Proceed with surgery and transfuse perioperatively as needed* - Proceeding without investigation is unsafe as **total hip replacement** involves significant blood loss, which would exacerbate an already severe anemia of 9.5 g/dL. - Transfusion addresses only the symptom of anemia but fails to address the underlying cause of **occult GI bleeding**. *Start oral iron supplementation and proceed with surgery in 2 weeks* - While **oral iron** helps replenish stores, it takes several weeks to significantly raise hemoglobin and does not diagnosticially address the **positive FOBT**. - Proceeding in two weeks is inappropriate because the diagnostic workup for the bleeding source (e.g., repeat **colonoscopy** or **endoscopy**) may take longer. *Give preoperative IV iron infusion and erythropoietin, operate in 3 days* - **IV iron** and **erythropoietin** are used for rapid preoperative optimization, but they are contraindicated as the sole management when the **etiology** of blood loss is unknown. - Operating in 3 days is premature, as it ignores the high likelihood of a significant **gastrointestinal pathology** suggested by the sharp drop from 14 g/dL to 9.5 g/dL. *Transfuse 2 units PRBCs preoperatively and proceed with surgery* - Preoperative **blood transfusion** carries risks of transfusion reactions and **TRALI**, and it should typically be avoided for elective surgeries if the anemia is correctable by other means. - Transfusion does not provide a diagnosis for the **GI bleed**, and a 5-year-old **normal colonoscopy** does not rule out new-onset lesions or cancer.

Question 7: A 45-year-old woman on warfarin for mechanical mitral valve replacement (INR therapeutic at 2.8) presents with acute cholecystitis requiring surgery within 24 hours. She has no history of thromboembolism beyond the indication for her valve. Apply the appropriate perioperative anticoagulation management.

A. Stop warfarin and proceed when INR <1.5
B. Give vitamin K, fresh frozen plasma, and proceed emergently
C. Stop warfarin, bridge with therapeutic heparin, operate when INR <1.5 (Correct Answer)
D. Continue warfarin and accept increased bleeding risk
E. Stop warfarin, bridge with low-molecular-weight heparin, proceed in 12 hours

Explanation: ***Stop warfarin, bridge with therapeutic heparin, operate when INR <1.5*** - Patients with a **mechanical mitral valve** are considered **high-risk** for thromboembolism and require **bridging therapy** with heparin when warfarin is discontinued. - For surgery within 24 hours, **IV unfractionated heparin** is preferred over LMWH because it can be stopped 4-6 hours before the procedure and reversed quickly if needed. *Stop warfarin and proceed when INR <1.5* - This approach is inappropriate for **high-risk** patients as it leaves them unprotected from **thromboembolic events** for several days while the INR drops. - A **mechanical mitral valve** has a higher thrombogenicity than an aortic valve, necessitating active bridging during the perioperative window. *Give vitamin K, fresh frozen plasma, and proceed emergently* - This is reserved for **life-threatening bleeding** or true **emergent surgeries** (within minutes to hours) where there is no time for heparin bridging. - **Acute cholecystitis** mentioned as requiring surgery within 24 hours is classified as **urgent**, not emergent, allowing time for a more controlled heparin bridge. *Continue warfarin and accept increased bleeding risk* - Operating with an **INR of 2.8** carries a significant and unacceptable risk of **intraoperative hemorrhage** for abdominal surgery. - Standard surgical practice requires an **INR <1.5** to ensure adequate **hemostasis** and safety during dissection and cautery. *Stop warfarin, bridge with low-molecular-weight heparin, proceed in 12 hours* - **LMWH** has a longer half-life than unfractionated heparin, making it less ideal for surgery planned within a **24-hour window** where flexibility is needed. - Proceeding in 12 hours is often insufficient for the **INR to normalize** naturally from a therapeutic level of 2.8 without reversal agents.

Question 8: A 72-year-old man with type 2 diabetes on metformin and glipizide is scheduled for coronary artery bypass grafting in 3 days. His HbA1c is 8.2%, fasting glucose is 185 mg/dL, and creatinine is 1.8 mg/dL. He will require contrast angiography the day before surgery. Apply the appropriate perioperative glycemic management.

A. Continue current medications until day of surgery
B. Stop metformin, continue glipizide, and start insulin therapy
C. Stop both oral agents and start insulin 48 hours before contrast (Correct Answer)
D. Add insulin to current regimen without stopping oral agents
E. Stop glipizide only and continue metformin with increased hydration

Explanation: ***Stop both oral agents and start insulin 48 hours before contrast*** - **Metformin** must be discontinued 48 hours prior to contrast administration and major surgery to prevent **lactic acidosis**, particularly in patients with **renal impairment** (Creatinine 1.8 mg/dL). - **Sulfonylureas** (glipizide) should be stopped to prevent prolonged **hypoglycemia** during the fasting (NPO) period associated with surgery and procedures. *Continue current medications until day of surgery* - Continuing **Metformin** carries a high risk of lactic acidosis if the patient develops **contrast-induced nephropathy** or perioperative renal failure. - Keeping the patient on oral agents fails to address the sub-optimal glycemic control (HbA1c 8.2%) required for high-risk **cardiac surgery**. *Stop metformin, continue glipizide, and start insulin therapy* - **Glipizide** has a significant risk of causing **hypoglycemia** when the patient is fasting for angiography and surgery; it provides no flexibility for titration. - Discontinuing only one agent while the patient is in a **hyperglycemic state** (Glucose 185 mg/dL) will not achieve the tight control necessary to reduce **surgical site infections**. *Add insulin to current regimen without stopping oral agents* - Adding **insulin** to oral agents increases the risk of unpredictable **hypoglycemic episodes** in a perioperative setting. - **Metformin** remains contraindicated in the presence of planned **iodinated contrast** and elevated creatinine levels. *Stop glipizide only and continue metformin with increased hydration* - Hydration alone does not mitigate the risk of **metformin-associated lactic acidosis** in a patient with an existing **creatinine of 1.8 mg/dL** undergoing contrast studies. - This approach ignores the standard safety guidelines which prioritize the early cessation of **biguanides** before major cardiovascular procedures.

Question 9: A 55-year-old woman with chronic obstructive pulmonary disease (FEV1 45% predicted) requires elective cholecystectomy for symptomatic cholelithiasis. She uses home oxygen at 2 L/min and has had two hospitalizations for COPD exacerbations in the past year. She smokes half a pack of cigarettes daily. Apply the most appropriate preoperative pulmonary optimization strategy.

A. Proceed with surgery after obtaining baseline arterial blood gas
B. Prescribe incentive spirometry training only
C. Smoking cessation, bronchodilator optimization, and delay surgery 4-8 weeks (Correct Answer)
D. Start prophylactic antibiotics and proceed within one week
E. Convert to open cholecystectomy under epidural anesthesia

Explanation: ***Smoking cessation, bronchodilator optimization, and delay surgery 4-8 weeks*** - Optimal preoperative management for high-risk **COPD** patients requires **smoking cessation** for at least **4 to 8 weeks** to significantly reduce **postoperative pulmonary complications (PPCs)**. - Maximizing **bronchodilator therapy** and ensuring clinical stability after recent exacerbations are essential steps to improve **FEV1** and reduce airway reactivity before elective surgery. *Proceed with surgery after obtaining baseline arterial blood gas* - Obtaining an **arterial blood gas (ABG)** provides a baseline for a chronic CO2 retainer but does not actively reduce the patient's high risk for **atelectasis** or pneumonia. - Proceeding without **optimization** in a patient with active smoking and severe COPD ignores modifiable risk factors that lead to **prolonged ventilation**. *Prescribe incentive spirometry training only* - While **incentive spirometry** and lung expansion maneuvers are helpful, they are insufficient as a standalone strategy for such a high-risk patient. - This approach fails to address the underlying **airway inflammation** and mucus hypersecretion caused by active **tobacco use**. *Start prophylactic antibiotics and proceed within one week* - **Prophylactic antibiotics** are not indicated for COPD optimization unless there is an active **respiratory infection** (purulent sputum or fever). - Proceeding within one week provides no benefit for **smoking cessation**, as short-term quitting (<4 weeks) may actually transiently increase **secretions**. *Convert to open cholecystectomy under epidural anesthesia* - **Laparoscopic cholecystectomy** is generally preferred over open surgery as it involves smaller incisions and results in less **diaphragmatic dysfunction**. - While **epidural anesthesia** can reduce the need for opioids, the surgical trauma of an **open procedure** typically leads to higher rates of PPCs compared to a minimally invasive approach.

Question 10: A 68-year-old man with a history of myocardial infarction 4 months ago is scheduled for elective inguinal hernia repair. He reports mild chest discomfort with climbing two flights of stairs but denies rest symptoms. His medications include aspirin, metoprolol, and atorvastatin. ECG shows Q waves in leads II, III, and aVF. Apply the appropriate preoperative cardiac risk stratification for this patient.

A. Proceed directly to surgery as hernia repair is low-risk
B. Order stress testing before proceeding with surgery
C. Obtain cardiology consultation and delay surgery 2 more months (Correct Answer)
D. Start prophylactic heparin and proceed with surgery
E. Convert to general anesthesia and proceed with intensive monitoring

Explanation: ***Obtain cardiology consultation and delay surgery 2 more months*** - According to **ACC/AHA guidelines**, elective noncardiac surgery should ideally be delayed for **6 months** following a **myocardial infarction** to significantly reduce the risk of perioperative cardiac events. - This patient is only **4 months post-MI** and exhibits **stable angina** symptoms; delaying the procedure allows for further cardiac optimization and stabilization of the recovery period. *Proceed directly to surgery as hernia repair is low-risk* - While inguinal hernia repair is considered a **low-to-intermediate risk** procedure, the patient's recent history of **MI (within 6 months)** and active **chest discomfort** categorize him as high risk. - Proceeding without addressing the established **cardiac risk stratification** guidelines increases the likelihood of a major adverse cardiac event (MACE). *Order stress testing before proceeding with surgery* - Stress testing is indicated for patients with poor **functional capacity** (<4 METs), but the immediate priority here is the timing relative to the recent **myocardial infarction**. - Since the surgery is **elective**, the primary intervention is to wait for the high-risk **6-month post-MI** window to pass before performing additional preoperative cardiac testing. *Start prophylactic heparin and proceed with surgery* - Prophylactic **heparin** is used for **venous thromboembolism (VTE)** prevention and does not address the patient's elevated risk of **perioperative MI** or ischemia. - Anticoagulation/antiplatelet management must be carefully balanced with surgical bleeding risks and is not a substitute for proper **cardiac risk stratification**. *Convert to general anesthesia and proceed with intensive monitoring* - **Intensive monitoring** (like arterial lines) does not inherently reduce the biological risk associated with a recent **myocardial infarction** for elective procedures. - The choice of **anesthesia** (general vs. regional) has not been definitively shown to reduce **cardiovascular mortality** in patients who are within the high-risk post-MI window.

Practice by Chapter

Cardiac risk assessment

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Pulmonary risk evaluation

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Medications management perioperatively

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Preoperative laboratory testing

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Preoperative imaging selection

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Antibiotic prophylaxis principles

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DVT risk assessment

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Nutritional assessment and optimization

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Frailty assessment

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Functional capacity evaluation

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Informed consent process

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Preoperative anesthesia evaluation

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Preoperative patient education

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