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Flashcards in Pre-op Assessment Deck (91)
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1
Q

Why do we “preop” a patient?

A

Minimize peri-operative mortality and morbidity
Minimize surgical delays
Determine post-op disposition
Evaluate patient’s health
Formulate anesthetic plan
Communicate issues among providers
*Gov’t over site requires a pre-anesthesia eval w/in 48 hrs of scheduled surgery

2
Q

Coronary risk factors

A
Smoking
HTN
DBM
HLD
Family hx
Socioeconomic status (access to care)
3
Q

Comorbidites related to cardiothoracic surgery include:

A
Respiratory
Neurological
PVD
Renal 
Thyroid
Peptic ulcer disease
Past cardiac surgery
4
Q

Why is knowing about past cardiac surgery important?

A

Re-do procedures associated with higer blood loss and morbidity

5
Q

Dental hygiene is important for what type of cardiac disease?

A

Valvular disease

6
Q

Criteria for low risk procedures

A
Low chance of:
bleeding
long surgery time
unlikely to cause surgical stress
<1% MACE
7
Q

Criteria for high risk procedures

A

High CV morbidity
Longer hospital stays
Higher risk of bleeding
>1% MACE

8
Q

Major Patient-related risk factors

A
Unstable angina
Recent MI (<6 weeks)
Malignant arrhythmias
-SVT
-2 or 3 degree AV blocks
-Symptomatic bradycardia
-VT
9
Q

Intermediate Patient related risk factors

A
Established CAD
Previous MI btwn 6 weeks-3 months prior to surgery
Stable angina
CHF with EF of < 35%
DBM
CKD with creat >2.0
CVA
10
Q

Minor Patient Related risk factors

A

Previous CABG more than 6 years before
Myocardial revascularization > 3 months negative stress test within the past 2 years
HTN
>70 years of age

11
Q

AHA recommendations for elective noncardiac surgery following Acute Coronary Syndrome

A

60 days

12
Q

What is one of the biggest indicators for post op major adverse cardiac complications?

A

Heart failure with EF < 30%

13
Q

AHA recommendations for pt with known valvular disease?

A

Echo w/in 1 year of surgery

14
Q

PHTN

A

High risk complications

Prevent hypoxia and hypercarbia to help with complications

15
Q

Perioperative myocardial inury (2 stages)

A

Stunning (temporary)

MI (cell death)

16
Q

Determinants of perioperative myocardial injury

A

Disruption of blood flow
Re perfusion of ischemic myocardium
Adverse effects from bypass (inflammatory cascade and immune system activation)

17
Q

Morbidity and mortality rate of pts with periopertive MI

A

49% (vs 4% of those that do not)

18
Q

What is time limit of ischemia before necrosis occurs?

A

20 minutes

19
Q

What is the wavefront phenomena?

A

necrosis starts in the subendocardial region and progresses to the subepicardial region

20
Q

What is the primary trigger for apoptosis

A

Acidosis

21
Q

MI diagnosis

A

1 biomarker in 99th percentile and any of these symptoms:
ECG changes
Echo with RWMA
Patient symptoms

22
Q

MI biomarkers

A
Myoglobin
CK
CK-MB
Troponin
LDH
23
Q

Peroperative MI definition in CABG

A

elevation of more than 10x the 99th percentile of normal

24
Q

Which biomarkers show immediately with MI?

A

None

25
Q

Order biomarkers occur

A
Myoglobin - peaks at 4 hours
CK - peaks at 16 hours
CK-MB - 24 hours
Troponins - 24 hours
Lactate - 72 hours
26
Q

What is the most reliable assessment of contractile dysfunction?

A

TEE - RWMA can occur w/in 10-15 sec of ischemia onset

27
Q

ECG changes with MY

A

new Q waves of 0.03 sec
new QRS deflections
ST changes not reliable in OR because of body placement and lead placement, hypothermia, electrolyte imbalances

28
Q

Parsonnet Index

A

Risk model derived from 3500 operations to provide approximation of risk based on 47 factors

29
Q

STS National Adult Cardiac Surgery Database

A

largest database for nwer risk-adjusted scoring system
100K pts analyzed
30 risk factors
Highest mortality rates seen in renal failure, emergent status, multiple reoperations, and NYHA class IV status

30
Q

EurosCORE II

A

20K pts
Most widely used model and current standard for cardiac surgical risk
identifies multiple high risk pt comorbidities - pts are low, med, high risk
OK to assess pt for CABG and valve surgeries, but not combined

31
Q

Consistent risk factors for cardiac surgery

A
Every 5 years over age 60
Female
EF < 30%
Obese
Reoperation
Type of surgery
Emergent surgery
32
Q

METs

A

Excellent >10
Good 7-10
Moderate 4-6
Poor < 4

33
Q

Examples of 4 METs

A

walking up hill, running short distance
walk 4 city blocks
heavy work around house

34
Q

1 MET is equal to

A

basal metabolic rate - 3.5 mL O2/kg/min

35
Q

Non-Cardiac surgery risk tools

A

RCRI - evaluates 6 factors but is not surgery specific
ACS-NSQIP - surgery specific risk; preferred tool
Gupta- includes medical therapies

36
Q

T or F: High risk pts undergoing low risk procedures require ECG

A

False. Routine ECGs in asymptomatic patients is not useful. However, if surgery is not low-risk, ECG is warranted

37
Q

T or F: Lab markers for MI are are recommended for pts at high risk of complications that may benefit from an intervention

A

True

38
Q

T or F: Beta Blockers should be continued in non-cardiac surgery pts who have been taking these meds

A

True. Avoids acute withdrawl

39
Q

T or F: Beta Blockers should be started within 1 day of non-cardiac surgery

A

False. Increased risk of hypotension, stroke, and death. UNLESS pt at high risk fro MI

40
Q

T or F: Statins should be continued perioperatively

A

True. Pts having vascular surgery should have statin treatment initiated.

41
Q

T or F: Alpha 2 agonists should be initiated before noncardiac surgery

A

False. Increased risk of cardiac arrest, hypotension, AKI.

42
Q

T or F: Aspirin therapy in pts w/o stents is not recommended

A

True. Unless pt risk of MI is higher than surgical bleeding

43
Q

T or F: RBC transfusion increases O2 carrying capacity of the blood

A

False. 2,3-DPG and ATP must normalize. Recommend restrict transfusion < 7 g/dL in asymptomatic, hemodynamically stable pts without CAD. In pts with CAD, number is < 8 g/dL unless symptomatic

44
Q

Standard of care after stent placement is:

A

Dual anti platelet therapy wit aspirin and a P2Y12 platelet inhibitor. Continued for 6 weeks for bare metal; 1 year for DES.

45
Q

If pt has angioplasty with no stents, how long should wait before having elective surgery?

A

2 weeks

46
Q

IF pt having acute coronary syndrome should wait how long before elective noncardiac surgery?

A

60 days

47
Q

How long after DES should pt wait for elective surgery?

A

6 months

48
Q

T or F: Evidence is against using preoperative elective PCI to reduce risk of surgery

A

T. If noncardiac surgery is performed w/in 4 weeks of PCI, 10% chance of cardiac event

49
Q

BMS - endothelial stent coverage is complete by when? What is the significance?

A

12 weeks; risk of re-stenosis drops. IF noncardiac surgery w/in 6 weeks of BMS, risk of cardiac complications is 30%

50
Q

DES

A

perform better than BMS for 1st year, but similar after. Cause less long-term inflammation.

51
Q

What three physiologic responses occur after balloon angioplasty?

A
  1. Immediate arterial wall recoil w/in 24 hours
  2. Negative arterial remodeling
  3. Neointimal hyperplasia response of smooth muscle proliferation and migration
52
Q

Stent Restenosis peaks when?

A

4-12 months

When vessel is 50% with symptoms or 70% total, intervention needed

53
Q

Stent thrombosis

A

Occurs w/in 30 days. High risk pts have 2.5% chance

54
Q

What is the most widely used cardiac diagnostic tool

A

Echo. LV EF, RWMA, Valvular disease

55
Q

4 classifications of assessing RWMA during echo (LV)

A
  1. Normal
  2. Hypokinetic
  3. Akinetic
  4. Dyskinetic/anuerysmal
56
Q

RV diastolic function can be assessed how during an echo?

A

IVC. If collapses by 50% on inspiration, RA pressures are normal (<5 mmHg)

57
Q

Normal Mitral Valve

A

4-6 cm2

58
Q

Mitral valve stenosis

A

Mild - >1.5 cm2
Mod 1-1.5 cm2
Severe - 1cm2

59
Q

What is important to remember in pts with MS?

A

Preload

60
Q

Mitral valve regurg

A
Common with LV dysfunciton
Independent predictor of morbidity and mortality
Mild - <30%
Mod 30-49%
Severe - >50%
61
Q

Normal aortic valve

A

2.6-3.5 cm2

62
Q

Aortic stenosis

A

Mild - >1.5 cm2
Mod - 1-1.5 cm2
Severe < 1 cm2

63
Q

Concerns with AS

A

LVEDP increases - causing LV hypertrophy. Filling becomes dependent on LA contraction, leading to afib. In severe cases, LV systolic function declines

64
Q

Recommendations fro symptomatic hemodynamically significant AS prior to elective noncardiac surgery

A

AVR

65
Q

Aortic regurg

A

Mild - <30%
Mod - 30-49%
Severe - >50%

66
Q

Which has higher mortality rate? AR or AS?

A

AR

67
Q

Tricuspid regurg

A

Tricuspid annulus > 4 cm needs surgical correction

68
Q

Tricuspid stenosis

A

very rare

69
Q

Pulmonary Valve regurg

A

Very rare. PHTN

70
Q

Pulmonary valve stenosis

A

Usually congenital. Not well seen on Echo.

71
Q

Prosthetic valves

A

Difficult to assess on echo due to acoustic shadows

72
Q

Stress echo

A

Pt on treadmill or bike
12 lead ECG and BP
Ischemia dx with ST segment depression > 1 mm, fall in BP, or CP

Limited if pt on BB

73
Q

Pharmacologic stress test

A

Pt receives chronotropic/inotropic agent - dobutamine or a vasoldilator like adenosine. Atropine can increase sensitivity of the test

74
Q

Formula - cardiac output

A

CO = HR x SV

75
Q

Formula - SVR

A

[(MAP - RAP)/systemic blood flow ] x 80

76
Q

Myocardial Nuclear Scintigraphy

A

Most common dx tool to evaluate for MI in preop assessment. Performs better than exercise stress test.

CT or PET scan

Radioactive substance is injected and machine picks up the decay around the heart. Areas of scarring won’t have decay.

Mod to large areas of ischemia is associated with high sensitivity for risk of perioperative MI and death. A normal study has a very high negative predictive value

77
Q

CCT/Cardiac Computed Tomography

A

256-320 slices of heart
Ionizing radiation is used
Pts HR slowed to 60 bpm with BB to allow for imaging
94% dx of CAD and 99% negative predictive value
*Note. Only validated in pts with no known CAD

Gold standard for evaluating aorta

78
Q

Cardiac MRI

A

Function, flow, morphology, tissue eval, perfusion, angiography, metabolic studies of cardiac structures w/o radiation

Gold standard for BiVentricultar volumes, EF, and mass. Also gold standard for myocardial scarring eval, RV eval, and chronic thoracic aneurysm

Negative predicitve value for 3 yr cardiac events is 99%.

79
Q

Carotid artery stenosis

A

Major cause of stroke
Bruits on physical exam
US is performed first with CT or MRA performed if needed
Carotid exams should be done if pt has a bruit, hx of CVA, or PVD

80
Q

Renal artery stenosis

A

Cause of secondary htn

US performed initiially

81
Q

Coronary Angiography

A

Gol standard for coronary anatomy and severity of CAD
Indications: >40 in men, post menopause women, symptoms, LV dysfunction, CV risk factors

PCI has 99% success rate

Must be < 1 yr for pts undergoing CABG

ECG, coag studies H & H, GFR

Must have 5 lead ECG

82
Q

Contrast dye precautions

A

Allergies
Anticoagulant and antiplatelet effects
Induce transient HB, QT prolongation, hypotension
Nephropathy - esp pts with DBM, CKD, HF

Avoid hypotension, NSAIDS, provide hydration

Max dose for healthy kidneys is 4 mL/kg

83
Q

Dx of contrast induced nephropathy

A

Creat elevation > 0.5 mg/dl or 25% in 48 hours

Creat levels of 1/5 mg/dL or GFR < 60 mL/min red flag

84
Q

Right side Cath complications

A

RBBB, Complete HB, Valvular damage, perforation, paradoxical air embolus

85
Q

Left side cath complications

A

MI, VF, VT, stroke, thrombus

86
Q

EP lab - ablation

A

Catheter in femoral vessels; systemic heparinization required

Mapping areas of arrhythmia

Scar tissue created

Can be long procedures

87
Q

EP lab - cardioversion

A

Want to slow accessory pathways - not AV node - avoid BB, verapamil, digoxin. Do use amiodarone, procainamide.

Opioids have no effect on conduction system. Volatile agents depress AV node but also depress accessory pathway conduction so ok to use.

Paralytics that have cholinergic effects (Succ, pancuronium) avoided

Avoid sympathetic stimualtion

88
Q

Postop care Handoff

A
What procedure performed
TEE results
Ease of transitioning from bypass
What inotropic support needed
Prescribed hemodynamic parameters
89
Q

Tamponade

A

hypotension, raised CVP, pulses paradoxus, ECG dampening

90
Q

Arrhythmias post op

A

Common
Check electrolytes - K and Mg common causes
Brady most common after valve surgery
Afib most common overall - 90% of pts that were in SR before will return

91
Q

Complications after cardiac surgery

A
  1. Device related infections (IEDs, LVAD) - mortality up to 35%
  2. Sternal wound infections - 7% mortality rate
  3. Endocarditis - prosthetic valve