Casefiles 1: pre/periop management, shock

Question 1

Perioperative treatment with ? is a strategy that is no longer applied as a cardiac-risk-reduction strategy, because of the increase in risk of cerebral ischemic events

Answer 1

beta-blockade

statin therapy is more beneficial

Question 2

Perioperative cardiac risk is low when patients have undergone successful ? within 5 years or ? between 6 months to 5 years prior.

Answer 2

surgical coronary revascularization

percutaneous coronary interventions (PCI)

Question 3

? were the strongest predictors of perioperative mortality

Answer 3

ASA class, age, mFI (modified frailty scores), and wound class

Question 4

AMERICAN SOCIETY OF ANESTHESIOLOGISTS (ASA) STATUS CLASSIFICATION SYSTEM

Answer 4

ASA (1) healthy person;
ASA (2) mild systemic disease;
ASA (3) severe systemic disease;
ASA (4) severe systemic disease that is a constant threat to life;
ASA (5) moribund individual who is not expected to survive without the operation;
ASA (6) a declared brain-dead person undergoing organ procurement.
An “E” is added to the end of the ASA class if the operation is an emergency procedure that cannot be delayed.

Question 5

Rivaroxaban’s half-life is related to the patient’s ?

Answer 5

creatinine clearance; therefore, it would be helpful to quantify the patient’s creatinine clearance prior to surgery
last dose should be btw 2-3 days prior to sx

Question 6

general recommendation is to defer elective surgical procedures for at least ? after bare-metal stent placement and to defer surgery for ? after the placement of drug-eluting stents

Answer 6

6 weeks
6 to 12 months

to prevent stent thrombosis
if delaying sx is not an option: need to continue his dual anti-platelet therapy and proceed with his operation

Question 7

CHAD2 scoring factors

Answer 7

CHF (1 point), Hypertension with systolic BP greater than 160 mm Hg (1 point)
Age more than 75 years (1 point),
Diabetes (1 point), and prior cerebrovascular accident (CVA) (2 points)

Question 8

CHAD2 scoring

Answer 8

High-risk group: scores of 5 to 6; moderate-risk group: scores of 3 to 4; and low-risk group: scores of 0 to 2

Question 9

stop warfarin ? before surgery and resuming warfarin dosing ? after the operation

Answer 9

5 days

12 to 14 hours

Question 10

may need to bridge warfarin with heparin or LMWH in what surgical patients?

Answer 10

A patient with a mechanical valves, at high risk for venous thromboembolism, or atrial fibrillation with high stroke risk

Question 11

Dabigatran (Pradaxa)

If necessary, ? can be performed to speed up the reversal of the drug effects.

Answer 11

oral direct thrombin inhibitor with a plasma half-life of 12 to 17 hours.
contraindicated in patients with severe renal dysfunction.
can monitor effects with aPTT and PT
hemodialysis can reverse drug effects

Question 12

New oral anticoagulants (NOACs) are approved for what conditions

Answer 12

prevention of strokes and embolic complications associated with a fib, the treatment of DVTs and PEs, secondary prevention of DVT, and DVT prevention following knee or hip replacements.

Question 13

Rivaroxaban (Xarelto)

Answer 13

oral direct factor Xa inhibitor with a plasma half-life of 5 to 9 hours in healthy individuals and 11 to 13 hours in elderly individuals.
contraindicated in patients with severe renal dysfunction.
metabolized and cleared by the liver, and levels may increase in liver failure patients

Question 14

Rivaroxaban (Xarelto) interacts with ?

Answer 14

antifungal agents, protease inhibitors, and rifampin

Question 15

anticoagulant effects of rivaroxaban can be determined based on ?
rivaroxaban can be reversed with ?

Answer 15

PT

activated prothrombin complex concentrate (aPCC) or prothrombin complex concentrate (PCC)

Question 16

Apixaban (Eliquis)

Answer 16

oral direct factor Xa inhibitor with a plasma half-life of 8 to 15 hours.
effects measured by plasma anti-Xa levels (if available)

Question 17

?? can be used to reduce bleeding in patients who develop excessive bleeding related to Apixaban (Eliquis)

Answer 17

four-factor PCC or aPCC

Question 18

The common antiplatelet agents that irreversibly inhibit platelet functions include ?

Answer 18

ASA, clopidogrel, ticlopidine, and prasugrel

with each day the medication is stopped, there is a 10% to 14% restoration of platelet activity

Question 19

reversible antiplatelet agents include ?

Answer 19

dipyridamole, cilostazol, and NSAIDs

Question 20

For patients with high risk for cardiovascular or cerebral vascular events, what is the recommendation for anti platelet therapies?

Answer 20

recommended that antiplatelet therapies be continued during the perioperative period

Question 21

For patients who are at moderate risk for cardiovascular events or are receiving antiplatelet agents for secondary prevention of cardiovascular diseases, what is the recommendation for antiplatelet therapy?

Answer 21

stop the antiplatelet therapy 7 to 10 days prior to surgery.

Question 22

NAOCs are contraindicated in ?

Answer 22

pregnant and/or breast-feeding patients

Question 23

Rivaroxaban and dabigatran are contraindicated in individuals with CrCl less than ?; apixaban is contraindicated in individuals with CrCl less than ?

Answer 23

30 mL/min

25 mL/min

Question 24

Which of the following is a favorable characteristic associated with the new oral anticoagulant treatment?

Answer 24

fewer drug-drug interactions than warfarin; however, drug-drug interactions between the NOACs and some of the antifungal medications are important to note
The can however contribute to bleeding complications and no drug level monitoring is usually required.

Question 25

NAOCs are not recommended for ?

Answer 25

the treatment of atrial fibrillation in patients with prosthetic valves
or in patients with low CHAD2 scores

Question 26

ongoing assessment for shock

Answer 26

central venous catheter for continuous CVP monitoring and an arterial catheter for ongoing BP monitoring
Trans-thoracic echocardiography to assess intravascular volume and evaluate cardiac function
Serial measurements of serum lactate levels

Question 27

central venous catheter

Answer 27

An intravenous catheter of sufficient length to measure the pressures in the superior vena cava when placed through the internal jugular vein or subclavian vein.

Question 28

What is lactate?

when elevated what does it imply?

Answer 28

end-product of anaerobic metabolism
suggests a global deficit in oxygen delivery
can also become elevated as the result of inadequate clearance, such as with renal dysfunction

Question 29

pulmonary artery catheter

Answer 29

A centrally placed catheter that can measure LV end-diastolic pressure and pulmonary artery pressures. can help gauge the patients’ LV functions

Question 30

pulmonary artery catheters vs CVP catheters

Answer 30

PA catheters rarely used in the ICU settings now due to invasiveness, CVP provides comparable info
real advantage of PA is monitoring of patients with poor cardiac functions who are maintained on inotropic agents (such as acute heart failure patients).

Question 31

Hypotension leading to shock can result from ?

Answer 31

decreased intravascular volume, cardiac pump failure, and/or acute vasodilation without sufficient increase in intravascular volume.

Question 32

Think of the cardiovascular system as an arrangement of pump, pipes, and fluid volume

Answer 32

cardiac output (pump), vascular tone (pipes), and intravascular volume (fluid)

Question 33

Hypovolemic surgical patients who respond initially to crystalloid resuscitation but then experience subsequent drops in blood pressure may have ?

Answer 33

ongoing bleeding that require operative intervention to control hemorrhage
resuscitations are generally more effective with the administration of blood products rather than crystalloids

Question 34

Excess crystalloid administration to a bleeding patient can cause ?

Answer 34

dilution of clotting factors and thrombocytopenia, which can cause further bleeding and create a vicious cycle of worsening hypotension, coagulopathy, and hypothermia

Question 35

etiologies of hypovolemic shock

Answer 35

Hemorrhage

Dehydration

Question 36

etiologies of distributive shock

Answer 36

Sepsis
Neurogenic
Anaphylaxis
Medications

Question 37

etiologies of intrinsic cardiac shock

Answer 37

Acute coronary syndrome

Cardiomyopathy

Question 38

etiologies of extrinsic cardiac shock

Answer 38

Cardiac tamponade
Tension pneumothorax
Massive pulmonary embolus

Question 39

normal hemodynamic variables

Answer 39

cardiac index: 2.4-3.0 L/min/m2
SVR: 800-1200 dyne-s or dyne-s/cm5
PCWP: 8-12 mm Hg
Prime Mover (initial causation): N/A

Question 40

hemodynamic changes in Distributive (sepsis, neurogenic, anaphylaxis) shock

Answer 40

elevated cardiac index
Decreased SVR (because of decreased vascular tone)
Low to normal PCWP
causation: Decreased vascular tone

Question 41

hemodynamic changes in Cardiogenic (MI, cardiomyopathy) shock

Answer 41

decreased cardiac index
Increased SVR
Increased PCWP
causation: Decreased cardiac contractility

Question 42

hemodynamic changes in Hypovolemic (hemorrhage, dehydration) shock

Answer 42

Decreased cardiac index (because of decreased volume)
Increased SVR (to attempt to maintain BP)
decreased PCWP
causation: decreased preload

Question 43

hemodynamic changes in Obstructive (tamponade, tension PTX, PE) shock

Answer 43

Decreased cardiac index
Increased SVR
Normal to increased PCWP
causation: Obstruction of blood flow

Question 44

most patients with distributive shock exhibit what symptoms? due to ?

Answer 44

gradual dips in BP or minimal responses to fluid administration due to microvascular leak syndrome or excess vasodilation

Question 45

appropriate treatments for distributive shock

Answer 45

vasoconstrictive medications such as norepinephrine for septic shock or phenylephrine (apha-1 agonist) for neurogenic shock rather than continued fluid administration

Question 46

sepsis vs severe sepsis vs septic shock

Answer 46

Sepsis: hyper dynamic and febrile responses to infections.
Severe sepsis: occurrence of infection with septic host response and at least one end-organ dysfunction.
Septic shock: sepsis with persistent hypotension despite fluid administration

Question 47

severe sepsis can carry a mortality of ? and septic shock can carry a mortality of ?

Answer 47

25% to 30%

50%

Question 48

The two major treatment goals in septic shock are to ?, and to ?

Answer 48

identify and address the source of infection (source control)
restore tissue perfusion as soon as possible to minimize remote organ hypoperfusion that can lead to organ dysfunction

Question 49

recommended end-points of resuscitation are target CVP of ?, a mean arterial pressure of greater than ?, and urine output greater than ?

Answer 49

8 to 12 mm Hg
65 mm Hg
0.5 mL/kg/h

Question 50

If fluids alone are insufficient to achieve the blood pressure goals, a ? is recommended to help achieve the target blood pressures once intravascular volume depletion has been corrected
if fails what next?

Answer 50

norepinephrine (Levophed) drip

• continuous infusion of vasopressin at a constant rate of 0.03 U/min can be initiated to help improve catecholamine receptor responsiveness
• corticosteroids for septic shock who do not achieve sufficient responses to source control, fluid administration, and vasopressors

Question 51

Source control in patients with a surgical infection frequently requires appropriate procedures to control the infection (eg, ?) in addition to antibiotics

Answer 51

drainage, debridement, bowel resection

Question 52

What patients may not exhibit the expected tachycardia response to hemorrhage until late in the course of shock

Answer 52

Patients younger than 30 years of age with a good cardiac reserve and patients on beta-blockers