Cardiac Anesthesia Flashcards
0
Q
Prophylaxis of infective endocarditis
A
Dental procedures in
- Prosthetic cardiac valves
- Previous IE
- Several types of congenital heart disease (CHD)
- Cardiac transplantation recipients who developed valvulopathy
1
Q
Hypothermia
A
- Plt sequestered reversibly in portal circulation
- Plt # back to normal w/I 1 hr
- Plt function & life span normal
2
Q
Energy for one MET
A
One MET=energy expended during 1 min at rest = 3.5 ml oxygen/kg/min
3
Q
CHD w/ right to left intracardiac shunt
A
- Tetralogy of Fallot
- Eisenmenger’s syndrome
- Ebstein’s malformation of tricuspid valve
- Pulmonary atresia w/ VSD
- Tricuspid atresia
- PFO
4
Q
ECG
A
- examing more than one lead is important
5
Q
PAC migration (922 ?)
A
- common (3-5 cm distally) withdrawal 3-5 cm before bypass
2. wedge position—>increase in PAP (r/o inadequate ventricular venting–>PAP w/o change after withdraw
6
Q
malposition of aortic cannula
A
unilateral facial blanching
7
Q
malposition of venous cannula
A
- too far into SVC (obstruction of R innominate vein) or
IVC (abd distention) - facial or scleral edema (bulging sclerae) or poor blood return to bypass circuit
8
Q
transposition of great vessels
A
- failure of truncus arteriosus to rotate–>aorta from RV, PA from LV
- induction: volatile—->slow; IV—>faster—>decrease dose
9
Q
Fontan procedure
A
- anastomosis: RA appendage—>PA
- tricuspid atresia, pulmonary stenosis, pulmonary artery atresia; hypoplastic left heart syndrome (–>increase PBF–>prepare convert RV to systemic ventricle)
10
Q
metabolic rate in CPB
A
Each degree Celsius decrease—>5 to 8% decline
11
Q
Itra-aortic balloon pump (IABP)
A
- Inflation immediately after closure of aortic valve (diastole)—>increase DBP & coronary BF
- Deflating just before ventricular systole—> Reduce aortic pressure and afterload—>enhance LV EF, reduce wall tension & VO2
12
Q
Afterload reduction beneficial
A
- AI
- MV
- CHF
- PDA
13
Q
Protamine
A
- From sperm of fish (certain)
- basic
- specific antagonist of heparin
- 1.3 mg/100 U of heparin
- Can bind plt & coagulation factors—>anticoagulant
- Allergy: NPH insulin
- Hypotension
14
Q
Primary determinants of myocardial O2 consumption, from most to least important
A
HR>afterload>preload
15
Q
Plusus paradoxus
A
- Pulsus paradoxus: inspiratory fall in SBP>10 mmHg<—cardiac tamponade
- occasionally: severe airway obstruction, RV infaction
16
Q
pulsus parvus vs pulsus tardus
A
- Pulsus parvus: diminished pulse
- Pulsus tardus: delayed upstroke
3, In AS
17
Q
Pulsus alternans
A
- alternating smaller and larger pulse waves
2. severe LV dysfunction
18
Q
Bisferiens pulse
A
- pulse waveform w/ 2 systolic peaks
2. AVR
19
Q
ETT drugs
A
ALONE: Atropine, Lidocanine, Oxygen, Naloxone, Epinephrine (Vasopressin may be)
20
Q
MAP
A
MAP = DBP +1/3 (SBP-DBP)
= 1/3 SBP + 2/3 DBP
21
Q
Amiodarone
A
- structure similar to thyroxine—>hypo or hyperthyroidism
- prolong AP w/o change resting potential: atrial & ventrical muscle
3 Effective: recurrent SVT & VT, WPW syndrome - anti-adrenergic effect—>bradycardia, hypoTN–>may be atropine-resistant—->isoproterenol or temporary pacer
22
Q
SVR
A
SVR=(MAP-CVP)/COx80
1. MAP & CVP: mmHg
2. CO: L/min
(1 wood = 80 dynes/sec/cm-5)
24
Q
dobutamine
A
predominantly beta 1-agonist
25
beta 1 vs beta 2 stimulation
```
Beta 1 stimulation
1. heat: HR, contractility, conduction velocity
2. release of fatty acids
Beta 2
1. vascular, rennin sectetion
2. airway
3. uterine relaxation
4. glycogenolysis, gluconeogenesis
alpha: intestinal and urinary bladder-sphincter tone
```
26
hypertrophic cardiomyopathy--anesthesia
1. goal: reduce gradient across LV outflow obstruction
2.avoid inotrope, reducing preload or afterload
3 halothane: direct myocardial depressant, not decrease SVR--->ideal
4. If hypotension--->phenyephrine
27
wide complex tachycardia--->unstable
1. presumed: ventricular tachycardia (VT)
2. medical emergency
3. synchronized cardioversion
28
Romano-Ward syndrome
1. congenital
2. prolong QT interval
3. If plus congenital deafness-->Jervell-Lange-Nielsen syndrome
4. etiology: likely imbalance: R & L sympathetic system
5. L stellate ganglion block--->shorten of QT--->surgical gangionectomy
29
VAD
1. Axiao = continuous, non-pulsatile
2. NIBP not accurate---> A-line
3. SPO2 may not work
30
Normal person, ?% CO is dependent on atrial kick
20 to 30 %
| but pathologic --->higher, e.g. AS
31
Tetralogy of Fallot (1 yo) --GA
1. Goal: maintain SVR
| 2. Ketamine 3 to 4 mg/kg IM or 1 to 2 mg/kg for induction
32
MS
1. rheumatic fever in childhood (almost exclusively)
2. LV: 'protected'=unloaded,
3. LA: decrease compliance & function--->pulmonary--->RV
33
PAC--> V wave on wedge pressure tracing
ischemia of posterior wall of LV & posterior leaflet of MV--->prolapse-->retrograde flow into LA-->V wave (can be earlier than ST depression (-->nitroglycerin)
34
Wide complex tachycardia of undetermined origin
If stable--->amiodarone 150 mg IV over 10 min--->repeat prn till 2.2 g over 24 hrs
35
amount of contisol
1. normal: 15 - 20 mg/day
| 2. Max stress: 75 - 150 mg/day
36
pace maker
1. stimulation threshold: increased by hypokalemia & respiratory alkalosis; vasa versa--->vulnerable to VF
2. decrease in HR >10%--->faterry failure-->cancel elective surgery-->evaluate
3. Anesthesia: ECG moniotor, emergency equipment(e.g, defibrillator, magnet), durgs (atropine, isoproterenol)
37
Fick equation
1. Q=VO2/(CaO2-CvO2)
2. CaO2=1.36 HgB x SaO2 + 0.003xPaO2
3. CvO2=1.36 HgB x SvO2 + 0.003xPvO2
4. VO2 = 4 ml/kg <----O2 consumption
38
Normal resting myocardial O2 consumption
Normal: 8 - 10 ml/100g/min---->2 in firillating heat @ 22 Celsus degree
39
AS
1. angina
2. syncope
3. CHF
Note: new Af--->electrical cardioversion
40
Prussure
```
RA: 3-8mmHg
RV: 15-30/3-8 mmHg
LA: 4-10 mmHg
LV: 100-120/3-12 mmHg
PA: 15-30/4-12 mmHg
```
41
PEEP
1. + pressure to exhalation valve @ end of expiratory
2. FIO2>0.5--->PEEP--->reduce O2 toxicity
3. Expand collapsed but perfused alveoli-->decrease V/Q
4. Decreased CO, pulmonary barotrauma (i.e., tension pneumothorax, pneumomediastinum, s.c. emphysema), increased extravascular lung water, redistribution of pulmonary BF5
5. If abrupt deterioration of SPO2 & CV fx--->suspect baratrauma-->CXR; tension pneumo-->chest tube
42
coronary artery BF
1. Resting coronary artery BF: 75ml/100g/min--> 225 to 250 ml/min-->4 to 5% CO
2. Resting myocardial O2 consumption: 8 to 10ml/100g/min--->10% total body O2 consumption
43
Pulmonary artery rupture associated with PAC
1. rare
2. hallmark: hemoptysis: may be minimal or copious
3. Try to separate lungs: DLETT
4. Atheromatous: not risk<---minimal or absent in middle or distal PA where tip of PAC is
44
Protamine reaction
1. Diabetics taking NPH or PZI insulin, but not regular insulin
2. seafood allergy
3. vasectomy: Antibody to spermatozoa
45
heparin vs protamine
1. 100 u heparin = 1.3 mg protamine
2. basic protamine vs acidic heparin
3. t1/2 of heparin = 1.5 hrs at 37 cesuls degree
46
cardiac perfusion
1. LV: during diastole-->increase HR-->decrease
| 2. RV: diastole and systole
47
thromboelastogram
1. viscoelastometer measuring viscoelastic properties of blood during clot formation
2. R value=reaction time: NL 7.5 to 15 mins
3. K value reflecting clot formation time: NL 3 to 6 mins
4. MA=max amplitude (max clot strength rate of clot destruction=fibrinolysis): -5 mm
48
170 micrometer filter
1 .present in standard blood administration sets
2. filtration of possible clots
3. Used for: Plt, FFP, Cryoprecipitate, pRBC, and granulocyte concentrate transfusion
49
Adenosine
1. SVT: 6 mg IV-->repeat if needed 1-2 min later 12mg
2. Including WPW syrdrome (unless AF w/ wide complex WPW occurs--->increase HR)
3. Dipyridamole or CVC: initial dose 3mg
4. Methylxanthine (caffeine, theophylline, amrinone)-->competitive antagonist to adenosine-->increase dose
50
body temperature measurement
1. PA, distal esophagus, tympanic membrane, or nasopharynx-->reliable even during rapid thermal perturbations such as CPB
2. oral, axillary, rectal, urinary bladder-->reasonably except during extreme thermal perturbation
3. In CPB pt measuring temp of both bladder and PA is helpful in determing likelihood of recooling after CPB
51
best intraop TEE view for monitoring myocardial ischemia
1. transgastric mid-papillary short axis view
| 2. supplied by all 3 major coronary ateries
52
sodium bicarbonate-->adverse effects
1. plasma hyperosmolality
2. paradoxic cerebral spinal fluid acidosis
3. hypernatremia
4. hypercarbia
53
hypercyanotic 'tet spells' in TOF
1. mechanism unknow: spasm of infundibular or decrease of SVR
2. mgt: phenylephrine, esmolol or IV fluid (morphine).
54
sildenafil (Viagra)
1. inhibit PDE5 ---inhibit breakdown of cGMP
2. Milrinone: inhibit PDE3
3. NTG & hydralazine: direct acting smooth muscle relaxants
55
Dural antiplatelet (ASA+clopidogrel)
1. DES: mim 1 yr before stopping prior to elective surgery
| 2. BMS: 1 month
56
HIT (heparin induced thrombocytopenia)
1. type I: nonimmune: heparin bind to plt-->short life-->modest decrease: transient-->insignificant clinically
2. type II: immume: ab to complex of heparin and a a PF4-->bind to endothelial cell-->thrombin productin-->thrombocytopenia (>50 reduction of plt) & V/A thrombosis (direct thrombin inhibitor: hirudin, leirudin, bivalirudin or argatroban
57
clopidogrel
1. noncompetitively and irreversibly inhibiting P2Y12 --->action is life long of plt-->no reverse drug
2. Platelet transfusion can reverse
58
port access robotic surgery
1. less invasive for coronary artery revascularization
| 2. mini-thoracotomy-->OLV-->hypoxia
59
carina vs bronchoscope
1. bronchoscope--two branch points: 'real' carina---> (L or R) two branch points: L upper lobe & lower lobe or RUL or RML--->3 lumens
60
hypoxia in OLV
1. check position of DLT and correction of poor hemodynamics
2. adding CPAP to non-dependent lung
3. adding PEEP to dependent lung
4. having surgeon clamp PA to lung about to remove
5. Intermittent inflation of non-dependent lung w/ O2
61
transplanted heart
1. denervated-->intrinsic HR 110
2. bradycardia(25%): eventually developed--->atropine no effect
3. Effective: glucagon, isoproterenol, epinephrine, norepinephrine (no reflex bradycardia), pacer
62
WPW syndrome w/ AVNRT (AV nodal reentrant tachycardia)
1. bundle of Kent: connet atria with ventricle w/o passing AV node
2. orthodromic: >90%, narrow complex, can use everything mentioned below
3. antidromic: travel via accessary pathway, worse, but Can use procainamide or electrical cardioversion
63
DDD-R reprogrammed to asynchronous (DOO) mode during surgery
1. VOO or DOO-->R on T likely if native HR >programmed HR or PVC or PAC
2. try Esmolol to decrease HR
64
Milrinone vs amrione (inamrinone)
1. PDE 3 inhibitor--->increase CAMP --->positive inotropic and vasodilation
2. Amrinone --->thrombocytopenia, but NOT milrinone
65
SVR vs PVR
SVR = (MAP - CVP )/CO
PVR = (PAmean - LA pressure)/CO
66
type of -tropy
1. chronotropy: HR
2. dromotropy: conduction
3. inotropy: force & velocity of ventricular contration
4. lusitropy: myocardial relaxation
5. bathmotropy: muscular excitation to stimulus
67
adrenergic receptors vs ach-receptors
```
alpha 1 (a, b, c)
alpha 2 (a, b, c)
beta 1, 2, 3
M1-
M2-heart
M3-coronary circulation
M4-
M5-
(M1, 3, 5: Gq/11-->PLC-->DAG; M2, 4-->Gi/o--> (-) AC
(M2 receptors can couple to K+ channels and influence the activity of calcium channels, If current, phospholipase A2, phospholipase D, and tyrosine kinases)
```
68
Bainbride reflex
stretch receptors in RA &cavoatrial juntin
69
Bezold-Jarisch reflex
1. vagal reflex
| 2. noxious ventricular stimuli
70
oculocardiac reflex
eye surgery
71
baroreceptor reflex
maintaining BP
72
SvO2 decrease vs increase
1. Normal: 60-80%
2. Decrease: Hypoxemia, low CO, anemia, increased oxygen consumption
3. Increase: decreased oxygen consumption (e.g. cyanide toxicity), elevation in CO, normalization of hemoglobin, improvement in oxygenation
73
Ketamine
1. Return to full orientation takes approximately 15-20 minutes after a typical induction dose of 2-2.5 mg/kg
2. active metabolite for ketamine: nonketamine
3. The safe use of ketamine in pregnancy has not been established, and such use is not recommended.
74
milrinone vs amrinone
1. Phosphodiesterase III inhibitors-->increase cAMP in cardiac & smooth muscle-->+inotropic & vasodilation (A & V)
2. amrinone: throbocytophenia
75
SIRS vs sepsis
```
SIRS needs 2 or more:
1. T>38 or 90
3. R>20 or PaCO2> 32
4. WBC >12,000 or 10% immature (band) forms
Sepsis = SIRS + documented infection
```
76
Distance from RA of PAC
1. RIJ: 20-25 cm (but RV: 30 - 35 cm; PA: 40 - 45 cm; wedge: 45 - 55 cm)
2. LIJ, LEJ, REJ: add 5 to 10 cm
3. Feoral: add 15cm
4. 30 to 35 cn from antecubital veins
77
pulmonary hypertension
1. mean PA >25 at rest or >30 mmHg w/ exercise
2. Epoprostenol = prostacyclin (PGI2); alprostadil (PGE1): central IV or inhale
3. O2
4. nitric oxide (NO): inhaled (1-80 ppm, typicl 20-40 ppm
5. Milrinone: also inotropic, ? inhale
6. inhaled volatile anesthetics
NOTE: nitrous oxide increase PA resistence
78
PVR as a function of lung volume is the least at ?
functional residual capacity (FRC)
79
Least likely to cause unfaovorable hemodynamic changes in MS ?
ketamine, remifentanil, pancuronium, desflurane, nitrous oxide
Remifentanil
80
torsades de pointes (twisting of the points)
1. can be induced by: drugs (e.g., quinidine, procainamide, phenothiazines like droperidol), electrolyte abnormalities (hypokalemia, hypomagnesemia), ACS
2. If prolonged QT present: shortening QT is time permits: overdrive atrial or ventricular pacing (more definitive), MgSO4 (1st line emergency), isoproterenol (past)
3. If no prolonged QT: std drugs for VT
4. hemodynamically unstable-->unsynchronized shock
