Exam 4 Flashcards
T/F: Perioperative β- blockade started within 1 day or less before noncardiac surgery increases the risk of hypotension, bradycardia, stroke, and death.
TRUE
Perioperative β- blockade started within 1 day or less before noncardiac surgery prevents nonfatal myocardial infarctions (MIs) BUT ALSO increases the risk of hypotension, bradycardia, stroke, and death.
β-blockade therapy should be instituted _______ days before surgery and titrated to a target
heart rate between __ and ___ beats per minute (bpm)
7-10 days
50-60 bpm
List some cardioprotective effects of statins:
- reduce vascular inflammation
- decrease the incidence of thrombogenesis
- enhance nitric oxide bioavailability
- stabilize atherosclerotic plaques
- lower lipid concentrations
a statin should be instituted __ days prior to the surgical procedure and continued
throughout the postoperative period
30
List Some Risk Factors Related to the Development of Atherosclerotic Lesions (13):
- Advanced age
- Smoking
- Hypertension
- Diabetes mellitus/insulin resistance
- Obesity
- Family history/genetic predisposition
- Physical inactivity
- Male gender
- Hyper or Hypohomocysteinemia
- Elevated C-reactive protein
- Elevated lipoprotein
- Hypertriglyceridemia
- Hyperlipidemia
Conditions and Traits Associated With Development of Abdominal Aortic Aneurysm (10)
- Smoking
- Older age
- Gender (more common in males than in females)
Family history - Coronary artery disease
- High cholesterol
- Chronic obstructive pulmonary disease
- Height (per 7-cm interval)
- Hypertension
- Peripheral vascular occlusive disease
- Whites
Which risk factor is the most highly correlated with AAA?
Smoking is the risk factor that is most highly correlated with
AAA.
Surgical intervention is recommended for
AAAs ___ cm or greater in diameter
5.5 (5)
T/F: An aneurysm has the potential to rupture regardless of its size.
TRUE, an aneurysm has the potential to rupture regardless of its size.
As the diameter of the aneurysm increases in size, however, the risk of rupture increases.
T/F: Prophylactic coronary revascularization reduces the incidence of perioperative cardiac events.
False
Prophylactic coronary revascularization does NOT reduce the incidence of perioperative cardiac events.
What is the primary method of intraoperative cardiac assessment in patients
undergoing surgery on the heart and the aorta?
TEE
what is a good analgesic option for patients with severely decreased ejection fraction?
Dexmedetomidine
functions to inhibit the sympathetic nervous system by decreasing central catecholamine release, does not inhibit respiration, and provides postoperative analgesia
what considerations should be taken with inhalation anesthetics for patients with CAD?
all inhalation anesthetics may depress the myocardium and cause hemodynamic instability. therefore high concentrations of inhalation agents should not be used in patients with a moderate to severe decreased ejection fraction
benefits of epidural anesthesia (8)
(1) decreased preload and afterload,
(2) preserved myocardial oxygenation,
(3) reduced stress response,
(4) excellent muscle relaxation,
(5) decreased incidence of postoperative thromboembolism, (
6) increased graft flow to the lower extremities, (
7) decreased pulmonary complications, and
(8) improved
postoperative analgesia
potential disadvantages of epidural anesthesia
possibility of an epidural hematoma (increases with anticoagulation) and severe hypotension during blood loss or unclamping
T/F: General anesthesia with TEA does not increase the risk of mortality, MI, or
neurologic complications compared to GA alone
TRUE
The use of a combined general anesthesia and epidural anesthesia provides the benefits of epidural anesthesia with the ability to provide amnesia and controlled ventilation.
Urinary output parameter for vascualr surgery
urine output of at least 1 mL/kg/hr.
Cardiovascular function must be closely monitored in the ICU for at least ___ hours after surgery
24
most common symptoms of a ruptured AAA
severe abdominal discomfort or pain
altered LOC caused by hypotension
pulsatile abdominal mass
other: syncope, groin/flank pain, hematuria, groin hernia
A patient with known AAA and cardiac disease is hypotensive in Preop. what should be done?
immediately transfer to OR for surgical exploration
Actions to protect kidneys with clamping of the aorta
minimize nephrotoxic medications such as NSAIDs (i.e. Toradol) and aminoglycoside antibiotics (i.e. gentamycin)
highest risk of kidney failure with which type of AAA
suprarenal clamp-time longer than 30 minutes
most significant in decreasing spinal ischemia?
short cross-clamp time
T/F: bair hugger is an appropriate method of maintaining normothermia during vascular surgery
FALSE
Bair huggers are contraindicated during vascular surgery clamping
most common origin of artery of adamkiewicz
T9-T12
What is a normal range for intracranial pressure (ICP) in adults?
10-15 mm Hg
What is the most common postoperative complication after carotid endarterectomy (CEA)?
Hypertension
Which is a disadvantage of aortic cross-clamping without bypass?
Risk of spinal cord ischemia
Which factor does NOT predispose to postoperative renal dysfunction?
* A. Prolonged aortic cross-clamp time
* B. Preexisting renal disease
* C. High intraoperative urine output
* D. Use of nephrotoxic agents (i.e. NSAIDs, aminoglyoside abx)
C. High intraoperative urine output
What is the primary purpose of transesophageal echocardiography (TEE) in aortic surgery?
* A. Monitor renal function
* B. Assess cardiac function
* C. Evaluate spinal cord perfusion
* D. Measure intracranial pressure
B. Assess cardiac function
What hemodynamic change occurs below the aortic cross-clamp?
Decreased blood pressure
Which medication class is suggested to be started 30 days prior to vascular surgery and continued postoperatively?
Statins
Symptoms of abdominal aortic aneurysm (AAA) rupture
Hypotension
Pulsatile abdominal mass
Back pain
What interventions helps prevent spinal cord injury during thoracic aortic surgery?
Hypothermia
CSF drainage
What is a common complication of aortic dissection?
* A. Paraplegia
* B. Hypertension
* C. Renal failure
* D. Stroke
C. Renal failure
Which intervention is appropriate for managing metabolic acidosis after releasing an aortic clamp?
A. Administering sodium bicarbonate
B. Increasing minute ventilation
C. Both A and B
D. Neither A nor B
C. Both A and B
During aortic cross-clamping, what occurs above the clamp?
Hypertension
If clamping is needed in CEA, cerebral perfusion is dependent on…
MAP
When carotid artery cross-clamping without shunting occurs, MAP values must be 20% or greater of the patient’s preoperative MAP to help ensure adequate cerebral perfusion through the contralateral carotid artery and
decrease the possibility of postoperative cognitive dysfunction.
Goals for EVAR (Select 2):
a. hemodynamic stability
b. minimize blood loss
c. ensure adequate analgesia
d. BP control with aortic cross-clamp
a. hemodynamic stability
c. ensure adequate analgesia
The goals for intraoperative management for EVAR include maintaining hemodynamic stability, providing analgesia and anxiolysis, and being prepared to rapidly convert to an open procedure.
Physiologic effect of aortic cross-clamping
metabolic acidosis
respiratory alkalosis
Mixed venous oxygen saturation (SvO2) increases when clamping occurs above the _______ due to reduced oxygen consumption.
CELIAC AXIS
Arterial pressure, blood flow, and oxygen consumption _______ below the clamp
DECREASE
What decreases with cross-clamping?
Left ventricular ejection fraction
Cardiac output
O2 consumption
Renal blood flow
BP below the clamp
What increases with cross-clamping?
MAP
SVR
Preload
Venous return
Coronary blood flow
Pulmonary artery wedge (PAOP)
AoDBP
Myocardial O2 consumption
SvO2 or mixed venous oxygen saturation
What decreases with release of the cross-clamp?
MAP
SVR
Preload
Venous return
Contractility
Coronary blood flow
Myocardial O2 consumption
RENAL BLOOD FLOW IS STILL A RISK DUE TO DECREASED MAP, SVR, AND CO!
SvO2 or mixed venous
What increases with release of the cross-clamp?
Total body oxygen delivery and consumption
Pulmonary artery pressure
PAOP, PVR
Strategies to reduce drop in SVR and MAP prior to release of cross-clamp?
IVF
Shorter cross-clamp times
Gradual/partial release of clamp
Vasopressors and/or inotropes
Decrease anesthetic depth
What does an EKG show
Ischemia
Myocardial hypertrophy
How do you increase O2 blood supply to the coronaries? (Select 3):
a. Hemoglobin
b. Diastolic time
c. Systolic time
d. Arterial oxygen content
e. Preload
f. Afterload
a. Hemoglobin
b. Diastolic time
d. Arterial oxygen content
Why is nitrous not used/contraindicated in thoracic surgery?
a. increased atelectasis in dependent lung
b. enhances HPV
c. increases PVR or pulmonary artery pressure
a. increased atelectasis in dependent lung
c. increases PVR or pulmonary artery pressure
Most common site of aneurysm
Infrarenal
Most common postop complication with CEA
Hypertension
What causes cerebral steal?
Hypercarbia (causes vasoDILATION)
Cerebral steal occurs when vasodilation in non-ischemic areas diverts blood away from ischemic brain regions, exacerbating ischemia.
