Week 1 Critical Illness/Ischemic Heart disease

Question 1

A 55-year-old patient with no history of diabetes presents with stress-induced hyperglycemia in the ICU. Which of the following mechanisms predominantly contributes to this condition?

Answer 1

Complicated hormonal, cytokine and nervous system signals on glucose metabolic pathways

–> insulin resistance in liver & skeletal muscles

Question 2

In critically ill patients, tight glycemic control targeting a blood glucose level of 80 to 110 mg/dL has been reconsidered because:

Answer 2

-found an increase in hypoglycemia & mortality

-2009 NICE SUGAR study no longer recs 80-110
-140-180 is current accepted range

Question 3

Sick euthyroid syndrome in critically ill patients is characterized by

Answer 3

• significant depression of T3 across all stages

-nonspecific alterations in thyroid hormone concentrations in patients who do not have intrinsic thyroid dysfunction that relate to the severity of the critical illness.
-systemic reaction involving immune and endocrine systems
-Decreases in serum gonadotropin sex hormone concentrations, T3/T4
-increased adrenocorticotropic hormone, and cortisol

Question 4

A patient in the ICU is diagnosed with relative adrenal insufficiency. Which of the following is the most likely cause?

Answer 4

impaired response to corticol at the tissue level due to sepsis

Other: impaired pituitary ACTH release, decreased adrenal responsiveness to ACTH, reduction in cortisol synthesis, impaired cortisol transport, impaired response to cortisol at the tissue level

Question 5

Acute renal dysfunction (AKI) in ICU patients is most closely associated with:

Answer 5

hypotension, sepsis and nephrotoxic agents

RF: age, baseline CKD, Oliguria, sepsis

Question 6

A 40-year-old male is admitted to the emergency department following a high-impact fall. He presents with severe hemorrhagic shock and a systolic blood pressure of 70 mm Hg. How could tranexamic acid be used in this scenario?

Answer 6

-Only admin if injury <3hrs ago, SBP < 75. 1g over 10 min followed by 1g over 8hrs

antifibrinolytic to bind with plasminogen to prevent activation to plasmin, interfering with the process of clot lysis. This slows bleeding. Part of evidence-based guidelines for adult trauma patients in severe hemorrhagic shock with known predictors for fibrinolysis or documented on TEG.

Question 7

A 45-year-old female patient is undergoing an emergency laparotomy because of a ruptured ectopic pregnancy. During the procedure, she experiences substantial blood loss. What is the most likely complication arising from this scenario, and what is the recommended initial management strategy?

Answer 7

Hemorrhagic Shock/coagulopathy treated with MTP

Mgmt: PRBC, control bleeding source. Early use of blood products over crystalloid. Permissive hypotension until bleeding is controlled. Correct hypothermia, acidosis, hypocalcemia, coagulopathy. Consider MTP.

Question 8

Fulminant hepatic failure in a patient can lead to (11):

Answer 8

MODS/death

encephalopathy —> high ICP, cerebral edema, sepsis, ARDS, hypoglycemia, coagulopathy, GI hemorrhage, pancreatitis, and ARF

Question 9

In managing pain in critically ill ICU patients, which of the following is a significant consequence of unrelieved pain?

Answer 9

–Catabolic hypermetabolism leads to hyperglycemia, lipolysis, and muscle wasting.

-chronic pain, PTSD, and low health-related QOL.
-Increased catecholamines-> vasoconstriction and impaired tissue perfusion/O2 delivery.
-Impaired wound healing and higher risk of infection

Question 10

A 60-year-old male, who has a history of chronic kidney disease, has been admitted to the ICU after undergoing major abdominal surgery. Postoperatively, he exhibits oliguria and a notable elevation in serum creatinine levels. What is the most likely diagnosis based on these findings, and what are the key elements of the initial management approach?

Answer 10

-AKI/ARF on CKD, optimize HDs and avoid nephrotoxic agents

-treating the cause (hypotension, sepsis, nephrotoxic meds) and avoiding further injury
-HD/CRRT

Question 11

A 65-year-old patient with a history of ischemic heart disease is scheduled for elective surgery. During the preoperative evaluation, which of the following factors would most significantly increase the patient’s risk of perioperative myocardial ischemia?

Answer 11

silent MI
Other:
a. Unstable coronary syndromes
b. Acute or recent MI with evidence of important ischemic risk based on clinical symptoms or noninvasive study
c. Unstable or severe angina
d. Decompensated HF or hx of HF
e. dysrhythmias: symptomatic ventricular dysrhythmias in the presence of underlying heart disease or high degree AV block
F. Severe valvular disease
g. Mild angina
h. Old MI with pathological Q waves
I. DM
J. Renal insufficiency
K. Age
L. pHTN
M. Poor functional capacity (<4METs)

Question 12

A patient with a history of coronary artery disease is undergoing elective surgery. To minimize the risk of stent thrombosis, perioperative management should prioritize:

Answer 12

continue ASA id DAPT stopped

(1) timing of the operation after PCI, also called the PCI-to-surgery interval
(2) continuation of dual antiplatelet therapy
(3) perioperative monitoring strategies
(4) anesthetic technique
(5) immediate availability of an interventional cardiologist
— delay elective sx (BMS 4W, DES 6-12mon)

Question 13

Which of the following best describes the pathophysiology of stable angina pectoris in a patient with ischemic heart disease?

Answer 13

partial occlusion or significant (>70%) narrowing of a segment of coronary artery.

Angina pectoris reflects intracardiac release of adenosine, bradykinin which stimulate cardiac nociceptive and mechanosensitive receptors whose afferent neurons converge with the upper 5 thoracic sympathetic ganglia and somatic nerve fibers in the spinal cord and produce thalamic and cortical stimulation that results in angina. These substances slow AV conduction and decrease cardiac contractility which improve the balance between myocardial O2 supply and demand. Atherosclerosis is the most common cause.

Question 14

A 70-year-old patient with ischemic heart disease presents with an acute myocardial infarction (AMI). Which of the following is the most likely underlying pathophysiological process?

Answer 14

Ruptured atherosclerotic plaque w/ subsequent thrombus rupture

Rupture of atherosclerotic plaque> release of vasoactive substances> activation of plts and coagulation cascade

Question 15

During an ischemic episode in a patient with IHD, which of the following ECG changes is most characteristic of subendocardial ischemia?

Answer 15

-ST segment depression in the area of ischemia that coincides with the timing of chest pain

-may also see T wave inversion (or return to upright T waves if previous MI)

Question 16

In a patient with ischemic heart disease undergoing noncardiac surgery, which of the following strategies is recommended to minimize the risk of stent thrombosis?

Answer 16

–Immediate post-op resumption of DAPT

The risk of stent thrombosis is significant in the first month after stent placement and progressively decreases as the time from PCI to surgery increases.BMS: waiting at least 30 days (preferably 90 days) before elective surgery is recommended. DES: waiting at least 1 year before elective noncardiac surgery is recommended

Question 17

A patient presents with severe chest pain and is diagnosed with STEMI. The most likely underlying cause of this presentation is:

Answer 17

–rupture of atherosclerotic plaque with subsequent thrombus formation which occludes the artery leading to ischemia and necrosis

abrupt decrease in coronary blood flow attributable to acute thrombus formation at a site where an atherosclerotic plaque fissures, ruptures, or ulcerates, creating an environment for thrombogenesis. A platelet monolayer forms at the site of ruptured plaque, and various chemical mediators such as collagen, ADP, epinephrine, and serotonin stimulate platelet aggregation. Thromboxane A2 is released, which further compromises coronary blood flow. Glycoprotein IIb/IIIa receptors on the platelets are activated, which enhances the ability of platelets to interact with adhesive proteins and other platelets and causes growth and stabilization of the thrombus. Further activation of coagulation leads to strengthening of the clot by fibrin deposition. This makes the clot more resistant to thrombolysis. In stable angina, collateral circulation develops, preventing the flow restriction seen in unstable angina and STEMI.

Question 18

In managing a patient with ischemic heart disease and acute myocardial infarction, the use of which medication is most directly associated with a reduction in mortality?

Answer 18

beta blockers

Question 19

A 60-year-old patient with a history of ischemic heart disease is scheduled for a high-risk surgical procedure. In the perioperative period, which of the following factors is the most significant predictor of perioperative myocardial infarction (PMI)?

Answer 19

–Elevated preop levels of cardiac specific trops

1. High risk surgery: AAA, peripheral vasc. surgery, thoracotomy, major abdominal
2. Ischemic heart disease: hx of MI, hx of positive exercise testing, current angina, use of nitrates, presence of Q waves on ECG
3. CHF: hx of CHF, hx of pulm edema, hx of paroxysmal nocturnal dyspnea, physical exam of rales of S3 gallop, CXR with pulm vasc redistribution
4. Cerebrovasc. disease: hx of stroke, hx of TIA
5. Insulin-dependent DM
6. Preoperative serum creat >2
   ^Lee RCRI risk stratification

Question 20

In the management of a patient with unstable angina/NSTEMI, which of the following diagnostic tools is most effective in confirming the diagnosis?

Answer 20

–Elevated levels of cardiac-specific troponins is key diagnostic criteria in NSTEMI

ST-segment depression in 2 or more contiguous leads and/or deep symmetric T-wave inversion, especially in the setting of chest pain

Question 21

A patient undergoing surgery develops signs of shock with a low cardiac index and vasoconstriction. Blood lactate levels are elevated. This scenario is most indicative of:

Answer 21

Hypodynamic Shock

(Hypovolemic/Obstructive/Cardiogenic Shock)

Question 22

In a patient with suspected pericardial tamponade developing shock, the most likely type of shock is:

Answer 22

obstructive

Question 23

In a patient experiencing massive blood loss during surgery, which of the following is the most appropriate initial management for coagulopathy?

Answer 23

–FFP

Early hemorrhage control, permissive hypotension until hemorrhage controlled, avoid crystalloids, early use of blood products/MTPs, Ca/K/temp correction

Question 24

For a trauma patient with severe hemorrhagic shock and evidence of fibrinolysis on thromboelastography, the most appropriate intervention is:

Answer 24

TXA

Question 25

A patient undergoing surgery experiences coagulopathy due to massive blood loss. The primary reason for administering fresh frozen plasma (FFP) in this scenario is to

Answer 25

replace clotting factors (all of them)

Question 26

In a patient with heparin-induced thrombocytopenia (HIT) experiencing bleeding, the administration of platelets is:

Answer 26

avoided d/t the risk of exacerbation of the prothrombotic state

Question 27

A patient reports anginal chest pain during exercise. The ECG demonstrates ST-segment depression and transient symmetric T-wave inversion. These findings are most indicative of:

Answer 27

Subendocardial ischemia

Question 28

Why is revascularization by PCI or surgery crucial in managing postinfarction ischemia, especially after ST-elevation myocardial infarction (STEMI)?

Answer 28

-Reduces infarct size

preserves LV function, and reduces short and long term mortality
-primary goal of stemi mgmt is to re-establish blood flow

Question 29

What is the primary pathophysiological target of rapid defibrillation in ventricular fibrillation following AMI?

Answer 29

To synchronize cardiac electrical activity and restore effective myocardial contraction

Question 30

Why is fluid administration critical in the management of right ventricular infarction?

Answer 30

Counteract RV preload and maintain CO

These patients are preload dependent

Question 31

What is the primary pathophysiological reason for the high risk of thrombosis following balloon angioplasty without stenting?

Answer 31

mechanical vessel injury and delayed reendothelialization

Mechanically opening a coronary artery by angioplasty causes vessel injury, especially destruction of the endothelium, making the area prone to thrombosis. 2-3 weeks to reendothelialize after balloon angioplasty

Question 32

Why is there a high risk of major adverse cardiac events (MACE) when surgery is performed within the first 6 weeks after bare-metal stent placement?

Answer 32

– Incomplete reendothelialization of the stented area

Highly vulnerable time for stent thrombosis, at high risk if DAPT therapy is held
-stent needs 6w to re-endothelialize
-surgical stress and inflammation can also activate plt and clotting cascade increasing risk

Question 33

What is the primary pathophysiological concern with using neuraxial anesthesia in patients on dual antiplatelet therapy?

Answer 33

spinal hematoma

Question 34

How does the duration of direct laryngoscopy during tracheal intubation impact patients with ischemic heart disease?

Answer 34

increased myocardial O2 consumption

Question 35

What is the primary pathophysiological effect of using volatile anesthetics in patients with ischemic heart disease?

Answer 35

Decrease myocardial O2 requirements

and may precondition the myocardium to tolerate ischemic events. May be detrimental d/t hypotension r/t vasodilation with associated reduction in coronary perfusion pressure

Question 36

What is the pathophysiological basis for using inotropic drugs to manage hypotension in patients experiencing myocardial ischemia?

Answer 36

To restore coronary perfusion pressure

Question 37

What is the pathophysiological reasoning for administering β blockers or calcium channel blockers during recovery from anesthesia in patients with ischemic heart disease?

Answer 37

–To regulate hemodynamic stress and myocardial O2 consumption

-avoid ischemia and reduce O2 demand

Question 38

In heart transplant recipients, why does the transplanted heart exhibit a blunted response to autonomic stimuli such as light anesthesia or intense pain?

Answer 38

The transplanted heart has no sympathetic, parasympathetic, or sensory innervation initially