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Flashcards in ITE Chiefs Review Deck (244):
1

What does P wave represent?

electrical activation of atria; precedes atrial contraction

2

Atrial systole contributes to __% of filling of ventricle

25%

3

What does QRS represent?

electrical activation of ventricles

4

What does T wave represent?

ventricular repolarization; marks end of ventricular contraction/rapid ejection

5

What action begins after QRS wave?

isovolumetric contraction

6

What is normal LVEDV?

120 mL

7

What is the average stroke volume?

80 mL

8

What are the three parts of systole?

1. isovolumic contraction
2. rapid ejection (2/3 LVEDV)
3. slower ejection

9

What are the four parts of diastole?

1. isovolumic relaxation
2. early filling (70-75%)
3. diastasis (<5%)
4. atrial systole (15-20%)

10

____ = amt of blood per minute

cardiac output

11

What four things affect cardiac output?

1. preload (LVEDV)
2. afterload (aortic pressure/BP)
3. myocardial contractility (inotropy)
4. HR (chronotropy)

12

The primary determinant of myocardial O2 consumption is ___.

HR

13

Formula for CO

CO = HR x SV

14

Formula for Ohm's law

Q (output) = pressure/resistance

15

An increase in ___ is most likely to result in increased myocardial wall tension

ventricular cavity size

16

What causes LVH?

chronic HTN (increased pressure load on LV) causes hypertrophy => decreased wall tension

17

Formula for LaPlace's law

T = Pr/2h
-T(ension)
-P(ressure)
-r(adius) of chamber
-h = wall thickness

18

Why do you diurese/venodilate CHF?

reduces preload => decreased radius, decreased wall tension, less myocardial O2 consumption

19

What happens to heart with decompensated HFrEF?

increased r and thin myocardium (decreased h) => increased wall tension

20

How is parasympathetic innervation of heart accomplished?

craniosacral: long preganglionic fibers with short postganglionic fibers in heart

21

Function of parasympathetic innervation of heart?

-slows HR
-reduces conduction velocity

22

What is the primary neurotransmitter for parasympathetics?

ACh

23

What neurotransmitters are involved in sympathetic innervation of heart?

1. ACh (stellate gang synapse)
2. NE (postganglionic)

24

How is heart innervated sympathetically?

thoracolumbar; synapse in stellate ganglion

25

Through what receptors in the heart does sympathetic innervation work?

beta-1: increases rate and conduction cells

26

What is the Bezold Jarisch reflex?

incr ventricular volume => vagal => decreased HR and MAP

27

Effects of sympathetic stimulation in heart?

1. chronotropic

2. dromotropic incr conduction velocity)

3. inotropic

4. lusitropic (incr rate of myofibrillar relaxation)

28

____ = systemic HTN in response to increased ICP

Cushing reflex

attempt to maintain cerebral perfusion/O2 delivery

29

What is the occulocardiac reflex?

pressure on ocular globe => brady, hypoT

30

What are the two types of sensitive receptors involved in heart innervation?

1. baroRs (arterial; depends on arterial BP)

2. chemoRs (periph; senses incr PaCO2, decr in pH)

31

During off pump CABG, a clamp is placed on a coronary artery. New onset junctional rhythm is seen on the EKG monitor and new inferior wall motion abnormalities are seen on TEE. What coro is affected?

RCA

32

What makes up the L main?

L main = LAD + L circumflex

33

What part of heart does the right main cover?

-ant/post RV wall
-RA
-SA node
-upper half of atrial septum
-post 1/3 interventricular septum
-inferior LV wall
-AV node
-post base LV

34

What circulation supplies the SA node and the AV node?

R main

35

What does the LAD supply?

-anterior LV wall
- anterior 2/3 of interventricular septum

36

What does the L circumflex supply?

-lateral LV wall
-part of LV posterior wall

37

Wall abnormality associated with RCA

RCA = inferior wall

38

Wall abnormality associated with LAD

LAD = anterior wall

39

Wall abnormality associated with circumflex

circumflex = lateral wall

40

Formula for coronary perfusion

coronary perfusion = aortic pressure (DBP) - LVEDP

41

What is resting coronary blood flow, and how much of cardiac output does it make up?

250 mL/min

5% of CO

42

What layer of heart tissue is most at risk for ischemia?

subendocardium

43

What does the Frank-Starling curve describe?

contractile state of myocardium

44

What three things are inotropic?

1. catecholamines
2. digitalis
3. sympathetic stimulation

45

What two things are negative inotropes?

1. pharm depressants
2. loss of myocardium

46

In what 4 cases is PAOP > LVEDP?

PAOP > LVEDP:
1. mitral stenosis
2. L atrial myxoma
3. pulm venous obstruction
4. elevated alveolar pressure

47

In what 3 cases is PAOP < LVEDP?

PAOP < LVEDP:
1. aortic regurg
2. stiff LV
3. LVEDP > 25 mmHg

48

25 yo man with known rheumatic heart disease is being evaluated in the ICU. Despite decreasing C.O., mixed venous blood from a PAC shows an increase in SvO2. Why?

wedging of catheter

49

The acute onset of hypotension without a decrease in mixed venous oxygen saturation in most likely associated with the onset of ____.

sepsis

50

In a patient with hypovolemic shock, what factor is the best measure of the overall balance between oxygen supply and demand?

mixed venous O2 sat

51

Formula for SvO2

SvO2 = SaO2 - (vO2/1.3 x CO x Hg)

52

What is a normal mixed venous O2 sat?

70%; 40 mmHg

53

With what tool must you measure mixed venous O2 sat?

PAC

54

With what tool must you measure mixed venous O2 sat?

PAC

55

What are the two broad reasons for decreased SvO2?

1. incr O2 consumption

2. decr O2 delivery

56

What are the four things that decrease SvO2 by increasing O2 consumption?

1. fever
2. shivering
3. MH
4. thyroid storm

57

What are the four things that decrease SvO2 by decreasing O2 delivery?

1. hypoxia
2. decreased CO
3. decreased Hgb (hemorrhage)
4. abnormal Hgb

58

Effect on SvO2:
fever

decreased SvO2

59

Effect on SvO2:
shivering

decreased SvO2

60

Effect on SvO2:
MH

decreased SvO2

61

Effect on SvO2:
thyroid storm

decreased SvO2

62

Effect on SvO2:
hypoxia

decreased SvO2

63

Effect on SvO2:
decreased CO

decreased SvO2

64

Effect on SvO2:
decreased Hgb

decreased SvO2

65

Effect on SvO2:
abnormal Hgb

decreased SvO2

66

Effect on SvO2:
L=>R shunting

increased SvO2

67

Effect on SvO2:
high CO

increased SvO2

68

Effect on SvO2:
cyanide

increased SvO2

69

Effect on SvO2:
hypothermia

increased SvO2

70

Effect on SvO2:
sepsis

increased SvO2

71

Effect on SvO2:
wedged PA

increased SvO2

72

What are some broad reasons for increased SvO2?

-L=>R shunt
-high CO
-impaired tissue uptake
-decr O2 consumption
-sepsis
-sampling error

73

Thermodilution is used to measure ___.

CO

74

What two issues invalidate thermodilution?
Why?

1. tricuspid regurg
2. cardiac shunts

only RV output is measured

75

How does thermodilution work?

1. known amt of fluid injected in proximal port of PAC (into RA)

2. temp measured at tip of PAC (in pulm a.)

3. temp change is inversly proportional to CO

76

What three things cause falsely high CO by thermodilution?

1. too little injectate
2. TR
3. cardiac shunts

77

Which of these are contraindicated in pulm HTN?
a) 15-methylprostaglandin F2alpha
b) sildenafil
c) nitric oxide
d) epoprostenol

15-methylprostaglandin F2alpha

78

MC sx associated with pulm HTN?

-incr SOB with activity
-CP at low exertion
-fatigue
-lethargy
-fainting
-leg swelling

79

What is the definition of pulm HTN?

mean PAP > 25 mmHg at rest

80

What are the 5 classifications of pulm HTN?

1. PAH
2. 2/2 L-sided heart dz
3. 2/2 lung dz/hypoxia
4. chronic thomboembolic pulm HTN
5. unclear/multifactorial

81

What are some predictors of poor outcome with surg/anesth?

-poor exercise capacity (6-min walk)
-elevated RA pressure
-decreased RV fxn/failure
-low CI
-elevated BNP
-elevated CRP

82

Moderate/severe pulm HTN is a contraindication for ____.

liver transplant

83

What are some goals for anesthetizing people with pulm HTN?

-prevent hypoT
-tx hypoT with phenylephrine, vasopressin, NE
-maintain adequate preload/contractility
-prevent hypoxia, hypercapnia, acidosis

84

Three classes of tx for pulm HTN?

1. prostacyclins (epoprostenol infusion, iloprost inhaled)

2. PDE inhibitors (sildenafil, tadalafil, milrinone)

3. consider inhaled NO

85

What is protamine?

only compound that reverses heparin

basic compound that binds acidic residues of heparin

86

What happens in a protamine reaction?

pulm HTN:
-heart pressure equalize = tamponade
-CO decr, PVR decr, SVR incr

87

What causes protamine reaction

increased plasma thromboxane

88

How do you treat a protamine reaction?

can do:
-epi
-heparin/bypass

89

What are the four components of the pathophysiology of protamine reaction?

1. coagulopathy

2. histamine release

3. IgE-mediated (type II): d/t prev sensitization (NPH, fish allergy, vasectomy)

4. anaphylactoid rxn (type III): complement/IgG; TXA2 release => severe pulm vasoconstriction, pulm HTN, possible R heart failure

90

A 77 yo woman with a biventricular implantable cardioverter-defibrilator (ICD) device is scheduled for an elective thyroidectomy. Interrogation of her device 2 days ago revealed 99.9% of beats were paced in DDD mode at 60 bpm. Per report, there is no underlying (intrinsic) cardiac rhythm. How do you prevent pacemaker inhibition by surgical electrocautery?

reprogramming pacer to asynchronous mode

91

Name four ways to inhibit/inactivate programmable DVI pacemaker.

1. myopotentials from shivering
2. succ-induced fasciculations
3. ventricular R wave
4. magnet over it

92

T or F: AICDs are not affected by ECT.

true

93

Name four things that affect AICDs.

1. MRI
2. radiation
3. unipolar cautery
4. radiofreq ablation

94

Given the complete general defibrillator code of VVE-DDDRV, what is true about this ICD?

provides ventricular chamber antitachycardia pacing

95

What are the five parts of pacer codes, and what are the options for these?

1st = chamber paced
-0 (none), A, V, D (dual)

2nd = chamber sensed
-0, A, V, D

3rd = response
-0, T (triggered), I (inhibited), D

4th = programmability/rate modulation
-0, P, M, C, R

5th = antitachy fxn
-0, P, S, D

96

What are the four parts of ICD codes, and what are the options for these?

1st = shock chambers
-0, A, V, D

2nd = antitachy pacing chambers
-0, A, V, D

3rd = tachy detection
-E (electrogram), H (hemodynamic)

4th = antibrady pacing chambers
-0, A, V, D

97

What are the parts of the CPB machine?

-reservoir = grav-dependent; accumulates deoxy blood from venous circ

-heat exchange (uses water countercurrents)

-oxygenator (membrane or bubble)

-filter system

then returned to ascending aorta

98

What are the two types of CPB pumps?

1. centrifugal pumps
2. roller pumps

99

What are the cons of CPB centrifugal pumps?

potential for retrograde flow and exsanguination

100

What are the cons of CPB roller pumps?

-incr trauma to RBCs
-can pump massive amts of air into circuit

101

How do CPB centrifugal pumps work?

-nonpulsatile flow
-non occlusive (less RBC trauma)
-afterload dependent (no line rupture)
-no air can be pumped (less dense than blood)

102

How do CPB roller pumps work?

-occlude blood tubing and move forward
-generates high pos/neg pressures

103

In what type of cases is microultrafiltration used?

peds hearts

104

What are the benefits of microultrafiltration

-decr total body water
-blunts anemia/coagulopathy
-decr blood requirements
-narrows A-a gradient
-improved LV compliance/systolic fxn
-decr inotropic requirements
-decr pleural/pericardial effusions
-decr inflammatory markers

105

What is the choice induction agent for emergent cardiac tamponade surg?

ketamine

106

What is Beck's triad?

for tamponade:
1. hypoT
2. incr CVP
3. distant heart sounds

107

What is pulsus paradoxus?

decr in SBP >12 mmHg during inspiration

hallmark for tamponade

108

What EKG changes are seen with tamponade?

-electrical alternans (also seen with pericardial effusion)

-low-voltage QRS complexes

109

What do you see with PAC measurements in patients with tamponade?

PAOP = PAP = CVP

pressures equalize in heart

110

What are the hemodynamic goals when caring for someone with tamponade?

-incr HR/contractility to maintain preload

-incr afterload to maintain BP

-incr preload to promote filling

111

What do you use for patients with decreased CO in setting of isolated AI?

dobutamine

112

How do you want to keep someone's hemodynamics with PMH isolated AI?

"full, fast, forward"

-HR 80-100
-maintain preload
-decr afterload to promote fwd flow

but excessive tachy can => myo. ischemia

113

What two hemodynamic issues can increase regurgitant volume in AI?

1. bradycardia
2. increased SVR

114

A 75 yo man with aortic stenosis and coronary artery disease has a preinduction HR of 68 and a BP of 125/70. After induction with fentanyl, versed and pancuronium, the HR is 90 and the BP is 85/45. ECG shows new ST elevation in lead II. Most appropriate initial management is with what agent?

phenylephrine

115

After a ground level fall, a 65 year-old woman with severe aortic stenosis develops atrial fibrillation. Vital signs include HR 150 and irregular with BP 50/20 mmHg. The MOST appropriate initial treatment is
what?

synchronized cardioversion (unstable brady)

116

What is a specific anesthetic contraindication in patients with severe AS?

spinals/epidurals

if sympathetic block to T6, can cause decreased afterload

117

Hemodynamic goals in patients with AS?

-sinus rhythm at all costs
- keep HR 60-80
-maintain both preload/afterload

118

Hemodynamic goals in pts with MR?

"full, fast, forward" (like AI)

-HR goal 80-100
-avoid brady and acute incr in afterload

119

What can cause worsened regurgitant flow in MR?

-bradycardia
-acute incr in afterload
-excessive volume (can dilate LV)

120

A patient with a history of mitral stenosis but without evidence of congestive heart failure presents for emergency appendectomy. The patient’s EKG shows normal sinus rhythm, blood pressure is 140/85 mmHg, and heart rate is 105 beats/min. What would you give?

start beta-blocker

121

A 45 yo woman with mitral stenosis is scheduled for elective mitral valve replacement. 2 minutes after tracheal intubation, she develops new onset Afib with a rapid ventricular response of 150 bpm and a decrease in BP to 75/45. Which of the following is the most appropriate 1st step in management?

electrical cardioversion

if pt suddenly develops new rhythm and BP is unstable, ALWAYS SHOCK

122

Hemodynamic goals for MS?

-HR low (60-80)
-avoid large incr in CO
-preload incr but not fluid-overloaded

123

What is an issue that can happen in patients with MS?

LA dilated => promotes SVTs, esp afib

124

What do you do with the following in stenotic valvular lesions:
-preload
-afterload
-HR

MS, AS:

-preload: maintain
-afterload: maintain
-HR low

125

What do you do with the following in regurgitant valvular lesions:
-preload
-afterload
-HR

MR, AR:

-preload: keep high
-afterload: keep low
-HR high

126

What do you do with the following in tamponade:
-preload
-afterload
-HR

-preload: high
-afterload: high
-HR: high

127

What do you do with the following in HOCM/SAM:
-preload
-afterload
-HR

-preload: high
-afterload: high
-HR: low

128

What do you see on echo in patient with HOCM, in terms of the heart structure?

left ventricular hypertrophy (LV wall thickness > 15mm) in the absence of an enlarged ventricular cavity

can also be asymmetric septal hypertrphy

129

What are some other names for HOCM?

-asymmetric septal hypertrophy
-idiopathic hypertrophic subaortic stenosis

130

What do you see on echo in patient with HOCM, in terms of valvular issues?

SAM = systolic anterior motion of MV

131

Where is murmur for HOCM best heard?

left lower sternal border and apex

132

What increases HOCM murmur?

decr ventricular filling (Valsalva)

133

What improves HOCM murmur?

squatting

134

How is HOCM inherited?

autosomal dominant

135

Hemodynamic goals for HOCM?

-incr preload
-maintain afterload
-maintain NSR
-AVOID inotropes

136

What do you do preop for acute AR if:
-CI >2.1
-PCWP <18

nothing, just induce

137

What do you do preop for acute AR if:
-CI >2.1
-PCWP >18

diuretic

138

What do you do preop for acute AR if:
-CI <2.1
-PCWP <18

incr preload with fluids

139

What do you do preop for acute AR if:
-CI <2.1
-PCWP >18

inotrope

140

A healthy subject has indwelling arterial catheters simultaneously transducing pressures from the brachial, radial, femoral, and dorsalis pedis arteries. Which of the catheters is likely to record the HIGHEST systolic pressure?

dorsalis pedis

141

What does pulsus alternans indicate?

LV failure

142

What does collapsing pulse indicate?

-AR
-hyperdynamic circulation

143

What does pulsus biferens indicate

-AR
-HOCM

144

What does anacrotic pulse indicate

aortic stenosis

145

____ = arterial waveform seen with LV failure

pulsus alternans

146

____ = arterial waveform seen with AR or hyperdynamic circulation

collapsing pulse

147

____ = arterial waveform seen with AR or HOCM

pulsus biferens

148

____ = arterial waveform seen with AS

anacrotic pulse

149

A 32 yo man who is 5 years post heart transplant for cardiomyopathy is tachycardic at baseline on pre-op evaluation. What is the cause?

cardiac denervation

no sympathetic/parasympathetic input

preload dependent, but do respond to circulating catecholamines

150

What two agents can increase HR in post-tx patients?

1. epi
2. isoproterenol

151

What do you see on EKG of post-tx patients?

2 P waves (d/t 2 SA nodes)

152

What are some issues with post-tx cardiac health?

1. accelerated atherosclerosis
2. silent MI (no pain sensors)

153

What's the goal SBP range with aortic dissection?

90-120

to reduce aortic wall stress

154

What is/are the drug(s) of choice for BP maintenance in aordic dissection?

-sodium nitroprusside
-beta blockers

DON'T use nitroprusside alone, as it may raise shearing forces

155

A 55 yo man with a history of cocaine abuse presents to the operating room with a Stanford type A aortic dissection. He is awake, alert, and complaining of chest pain. His blood pressure is 75/40 mmHg, pulse 105 bpm, SaO2 95% on 2L nasal cannula. A 12 lead EKG reveals ST elevation in leads II, III, and aVF. An echocardiogram reveals large pericardial fluid with right ventricular compression during systole. What is the BEST initial management strategy for this patient?

surgical repair

156

A 58 yo woman is admitted to the intensive care unit after open repair of a type-III thoracoabdominal aortic aneurysm. Preoperatively, an intrathecal catheter was placed for cerebrospinal fluid drainage. Estimated blood loss was 6L, and PRBCs, cell saver blood, platelets, FFP, and cryoprecipitate were administered to treat anemia and coagulopathy. Postoperatively, the patient is unable to move her lower extremities. Sensation is normal. She has no back pain. What is MOST likely to account for her neurologic deficit?

anterior spinal a. syndrome

157

A 56 yo patient is undergoing a thoracic aortic aneurysm repair with the use of an aortic cross clamp. What vessel provides blood supply to the anterior 2/3 of the spinal cord?

artery of Adamkiewicz

158

What situation is MOST likely the cause of paraplegia following repair of a descending thoracic aortic aneurysm?

prolonged aortic cross-clamp time

159

What three vessels supply the spinal cord?

1. anterior spinal a: ant 2/3 of cord
2. posterior spinal aa: post 1/3 of cord
3. artery of Adamkiewicz (arteria radicularis magna): thoracolumbar radicular a. off aorta that is major blood suppy to anterior, lower 2/3 of spinal cord

160

____: loss of motor fxn (paralysis, ataxia) and sensation below lesion

Brown-Sequard syndrome
-lateral hemisection/transection of spinal cord
-spinothalamic tract, one or both dorsal columns and corticospinal tract

161

____: loss of motor fxn/pinprick sensation with preservation of vibration and proprioception

anterior spinal a. syndrome
-usually d/t ischemia or dissection
-bilat spinothalamic tract and corticospinal tract

162

What part of spinal cord is affected by anterior spinal a. syndrome?

bilat spinothalamic tract and corticospinal tract

163

What part of spinal cord is affected by Brown-Sequard syndrome?

spinothalamic tract, one or both dorsal columns, corticospinal tract

164

What are the two main causes of anterior spinal artery syndrome?

1. ischemia
2. dissection

165

What are the two overall methods of classifying aortic dissections?

1. Stanford
2. DeBakey

166

What are the two types of aortic dissections per the Stanford classification?

1. type A = ascending aorta
2. type B = descending aorta

167

What are the three types of aortic dissections per the DeBakey classification?

1. type I: ascending aorta, aortic arch, and descending aorta

2. type II: ascending aorta

3. type III: descending aorta distal to L subclavian a.

168

What are some signs of PE in the OR?

-hypoT
-hypoxemia
-bronchospasm
-decr etCO2
-incr CVP
-incr PAP (not PAOP)

169

A patient with a history of hypertension (baseline blood pressure 160/100 mmHg) experiences an acute myocardial infarction (MI). What risk factor is MOST likely to be associated with an increased risk of developing cardiogenic shock following an acute MI?

ST segment elevation MI

170

The diagnosis of cardigenic shock is established and the decision is made to institute intra-aortic balloon counterpulsation. What parameter is MOST likely to decrease as a result of this intervention?

LV afterload

171

What happens to each of the following in hypovolemic shock:
-HR
-MAP
-CVP
-PAOP
-SVR

Hypovolemic:
-HR = incr
-MAP = decr
-CVP = decr
-PAOP = decr
-SVR = incr

172

What happens to each of the following in cardiogenic shock:
-HR
-MAP
-CVP
-PAOP
-SVR

Cardiogenic:
-HR = incr
-MAP = either
-CVP = nml (LV fail) or incr
-PAOP = nml (RV fail) or incr
-SVR = incr

173

What happens to each of the following in distributive shock:
-HR
-MAP
-CVP
-PAOP
-SVR

Distributive:
-HR = incr (except maybe decr in neurogenic shock)
-MAP = decr
-CVP = decr/nml early, incr/nml late
-PAOP = decr/nml early, incr/nml late
-SVR = decr

174

What happens to each of the following in obstructive shock:
-HR
-MAP
-CVP
-PAOP
-SVR

Obstructive:
-HR = incr
-MAP = decr
-CVP = incr
-PAOP = incr
-SVR = incr

175

What defines severe sepsis?

sepsis + organ dysfxn

176

What differentiates SIRS from sepsis?

infectious etiology = sepsis

177

What defines septic shock?

sepsis + hypoT

178

What patients need endocarditis prophylaxis?

-prosthetic cardiac valve
-previous IE
-CHD (unrepaired cyanotic CHD, repaired CHD with prosthetics or within 1st 6 mo, or repaired with residual defects)
-heart tx with cardiac valvulopathy

179

What procedures need endocarditis prophylaxis in appropriate pts?

-dental procedures with gum manipulation/perf of mucosa
-procedures on resp tract, infected skin or muskuloskeletal tissue

180

What is a component of protocol for early (first 6 hrs) goal-directed therapy in tx sepsis?

central venous oxygenation sat of at least 70%

181

____ view is the most optimal TEE view to monitor intraop myocardial ischemia.

transgastric short axis

provides view of all 3 coronary a distributions

182

What is the primary cause of neurologic deficit following CEA?

thromboembolism

183

What's the best method to check for cerebral perfusion during CEA?

EEG

184

Following a carotid endarterectomy in a 72 year old man, the nurse in the postanesthesia care unit calls you to report the patient’s blood pressure is 220/103. His preoperative pressure was 140/80 mmHg. This is MOST likley due to denervation of what structure?

carotid sinus

185

What are the indications for CEA?

-TIAs with >70% occlusion
-severe stenosis with minor CVA
-mod occlusion (30-70%) in pts with ipsilat sx

186

What is the role of a shunt in CEA?

can place if signs of cerebral ischemia, but carry risk of thromboembolism

187

What is the major cause of mortality post-CEA?

myocardial ischemia (1-2%)

188

What are four types of post-op complications in CEA, and why?

1. HTN: pain, hypoxemia, hypercarbia, surgical denervation of ipsilat carotid baroR (carotid sinus)

2. hypoT: removal of atheroma exposes baroR (carotid sinus) to higher BP, causing brain stem-mediated hypoT/brady

3. resp insufficiency: damaged to recurrent laryngeal n, impaired carotid body response to hypoxemia

4. neuro deficits: thromboembolism (causing cerebral hypoperfusion), regional cerebral hyperperfusion

189

After termination of cardiopulmonary bypass, a patient who is chronically digitalized receives digoxin 0.5 mg in error. An EKG shows sinus brady with intermittent sinus arrest. Blood pressure is 90/60. What BP drug is contraindicated?

calcium chloride

190

What electrolyte abnormalities are associated with digoxin toxicity?

Dig Tox May Keep Coming Back:

-decr Thyroid
-decr Mag
-decr K
-incr Ca
-incr BUN

191

What are the factors looked at with the RCRI?

-ischemic heart dz
-CHF
-CVA
-Cr > 2.0
-IDDM
-high-risk surg

if 3 or more, consider more workup

192

If you have 2 RCRI factors, risk of cardiac complications is __%, whereas with 3 RCRI factors it is __%.

2 = 7% risk
3 = 11% risk

193

What innervates diaphragm?

phrenic n. (C3-C5)

194

How much does unilat phrenic n. injury affect pulm fxn?

25%

195

What does general anesthesia do to O2 consumption and CO2 production?

reduces VO2 and VCO2 by 15% (mostly within cerebral/cardiac metab)

196

What effect does vagus n. have on lungs?

parasympathetics via muscarinic Rs:
-bronchoconstriction
-incr bronchial secretions

197

What type of sympathetic Rs are present in lung tissue, and what are their actions?

-beta-2: bronchodilation, decr bronchial secretions

-alpha-1: decreased secretions, maybe bronchoconstriction

198

How do sympathetics/parasympathetics act on lung vasculature?

sympathetic:
-alpha-1: vasoconstrxn
-beta-2: vasoD

parasympathetic:
-vasoD via nitric oxide

199

Formula for transpulmonary gradient

P(transpulm) = P(alveolar) -- P(intrapleural)

+5 at end expiration, -4 at inspiration (gradient)

200

A patient under general anesthesia maintains saturation levels of 85-90%. Despite 100% oxygen therapy the saturation does not rise above 90%. What is the MOST likely reason?

methemoglobinemia

201

What 6 things cause left shift on O2-Hgb dissociation curve?

1. hypothermia
2. alkalosis
3. decreased 2,3-DPG
4. fetal Hgb
5. carboxyHgb
6. methemoglobin

202

What 6 things cause right shift on O2-Hgb dissociation curve?

1. hyperthermia
2. acidosis
3. incr 2,3-DPG
4, abnormal Hgb
5. incr CO2
6. pregnancy

203

What effect does the following have on the O2-Hgb dissociation curve:
hypothermia

left shift

204

What effect does the following have on the O2-Hgb dissociation curve:
alkalosis

left shift

205

What effect does the following have on the O2-Hgb dissociation curve:
decreased 2,3-DPG

left shift

206

What effect does the following have on the O2-Hgb dissociation curve:
fetal Hgb

left shift

207

What effect does the following have on the O2-Hgb dissociation curve:
carboxyHgb

left shift

208

What effect does the following have on the O2-Hgb dissociation curve:
methemoglobin

left shift

209

What effect does the following have on the O2-Hgb dissociation curve:
hyperthermia

right shift

210

What effect does the following have on the O2-Hgb dissociation curve:
acidosis

right shift

211

What effect does the following have on the O2-Hgb dissociation curve:
increased 2,3-DPG

right shift

212

What effect does the following have on the O2-Hgb dissociation curve:
abnormal Hgb

right shift

213

What effect does the following have on the O2-Hgb dissociation curve:
incr CO2

right shift

214

What effect does the following have on the O2-Hgb dissociation curve:
pregnancy

right shift

215

What is normal lung compliance?

150 - 200 ml/cm H2O

216

Formula for lung compliance

change in lung vol/change in transpulm pressure

217

formula for chest wall compliance

change in chest vol/change in transthoracic pressure

218

Name three factors that reduce lung compliance

1. pulm fibrosis
2. pulm edema
3. consolidation

compliance incr by emphysema

219

Name three factors that reduce chest wall compliance

1. severe obesity
2. laparoscopy
3. incr abd pressure

220

Name 5 intraop issues that can decrease lung compliance

1. mainstem intubation
2. bronchospasm
3. pneumo
4. changes in position
5. insufflation of abd

221

What does it mean when the compliance curve is shifted to the R?

addition of PEEP

222

What does it mean when the compliance curve is flattened?

incr airway resistance

223

What does it mean when the compliance curve doesn't return to zero?

leak

224

What lung measurement can be made with an IS?

inspiratory reserve volume

225

What effect does obesity have on the following:
pulm compliance

decr

226

What effect does obesity have on the following:
FRC

decr

227

What effect does obesity have on the following:
vital capacity

decr

228

What effect does obesity have on the following:
TLC

decr

229

What effect does obesity have on the following:
expiratory reserve volume

decr

230

What effect does obesity have on the following:
residual volume

unchanged

231

What effect does obesity have on the following:
closing capacity

unchanged

232

What effect does obesity have on the following:
O2 consumption

incr

233

What effect does obesity have on the following:
CO2 production

incr

234

What is the average adult tidal volume?

500 mL

235

What is the average adult inspiratory reserve volume?
What does IRV mean?

3000 mL

max additional vol that can be inspired above TV

236

What is the average adult expiratory reserve volume?
What does ERV mean?

1100 mL

max vol that can be expired below tidal vol

237

What is the average adult residual volume?
What does RV mean?

1200 mL

vol remaining after max exhalation

238

What is the average adult TLC?
Formula for TLC?

5800 mL

RV + ERV + Vt + IRV

239

What is the average adult FRC?
Formula for FRC?

2300 mL

RV + ERV

240

What is closing capacity?

volume that small airways and alveoli begin to close in dependent parts of lung

incr with age

241

What is the normal ratio of FEV1/FVC?

>80%

242

What is a shunt?

desaturated, mixed venous blood from R heart returns to L heart without being oxygenated

243

If minute ventilation remains constant, what happens to PetCO2 and PaCO2 will result from a decrease in cardiac output?

PetCO2 decreases

PaCO2 increases

244

What are three factors that can incr physiological dead space?

1. decreased CO
2. PE
3. upright position