Exam 2 Flashcards
1
Q
List the order of vessels branching off from the Aortic Arch
A
- Aortic Arch
- Brachiocephalic which becomes the Right Subclavian, then the Right Common Carotid Artery
- Left Common Carotid Artery
- Left Subclavian
2
Q
What percentage of live births are affected by congenital heart defects
A
1% (7-10/1000)
3
Q
2 examples of anatomic shunts
A
- ASD (atrio-septal defect)
2. VSD (ventriculo-septal defect)
4
Q
Name and describe the 3 shunts in fetal circulation
A
- Ductus Venosus - fetal blood vessel connecting the umbilical vin to the IVC, bypassing the liver (~50% of blood)
- Foramen Ovale - allows most of the oxygenated blood entering the right atrium to pass to the left atrium, bypassing pulmonary circulation.
- Ductus Arteriosus - Shunts blood from pulmonary trunk to aorta
5
Q
In fetal circulation, which ventricle provides systemic blood flow? What type of circulation (parallel or series)?
A
both ventricles provide systemic blood flow through parallel circulation
6
Q
Where does oxygenated blood from the placenta return to the fetus?
A
Umbilical vein
7
Q
Pvr is ___ and redirects ___ of blood into the ___ aorta via the ductus arteriosus in normal fetal circulation
A
Pvr is high and redirects 90% of blood into the descending aorta via the ductus arteriosus
8
Q
What is the O2 Sat of blood entering the ascending aorta from the RA? Blood from the LV?
A
RA Blood O2 sat is 65-70% and oxygenates the brain and heart in utero. LV blood O2 sat is 55-65% and returns to the placenta.
9
Q
What type of atmosphere is a growing fetus in?
A
Relatively cyanotic
10
Q
What other type of defects are children with CHD usually born with?
A
Neurological
11
Q
What changes in the fetal body does a reduction in alveolar PCO2, reduced prostaglandin circulation and increase in alveolar PO2 after cord clamping lead to?
A
A reduction in PVR which increases pulmonary blood flow and increases LV volume and afterload
12
Q
When do we expect the ductus arteriosus to close by?
A
58% by day 2 and 98% by day 4
13
Q
What causes closure of the ductus venosus?
A
Portal pressure falling after umbilical vein ligation
14
Q
What causes functional closure of the foramen ovale?
A
LA pressure exceeding RA pressure
15
Q
In what percentage of children <5 years old does a PFO remain anatomically patent? Adults?
A
Children <5 = 50% (this is why it is very important to eliminate any micro bubbles in IV tubing and syringes)
Adults 25-30%
16
Q
At what time period do we expect there to be fibrous tissue where the ductus venosus was?
A
at about 3 months
17
Q
What is the definition of shunting?
A
Shunting is when venous return in one circulatory system is recirculated through the arterial outflow of the same system
18
Q
__ atrial blood shunted to aorta produces recirculation of systemic venous blood, resulting in a __ to __ shunt
A
Right atrial blood shunted to aorta produces recirculation of systemic venous blood, resulting in a right to left shunt
19
Q
__ atrial blood shunted to the pulmonary artery produces recirculation of pulmonary venous blood, resulting in a __ to __ shunt
A
Left atrial blood shunted to the pulmonary artery produces recirculation of pulmonary venous blood, resulting in a left to right shunt
20
Q
What is a physiologic shunt? Anatomic shunt?
A
Physiologic shunts are a recirculation of blood, usually as the result of an anatomic shunt.
Anatomic shunt is the communication between cardiac chambers or great vessels
21
Q
Which type of shunt (large or small) is highly dependent on PVR and SVR
A
large shunts
22
Q
3 examples of Acyanotic defects
A
- PDA
- ASD
- VSD
These recirculate pulmonary venous blood = left to right shunt
23
Q
5 characteristics of acyanotic defects
A
- Increased Fatigue (even with things such as normal daily feeding)
- Heart murmurs
- Increased risk of endocarditis
- CHF
- Growth retardation
24
Q
6 things to avoid with left to right shunts
A
- Vasodilators
- 100% FiO2
- Decreased PCO2
- Alkalosis
- Increase in SVR
- Decrease in PVR
3 and 4 can decrease PVR, which increasing pulmonary blood flow, increased the left to right shunt
25
5 physiologic results of left to right shunts
1. Decreased systemic perfusion
2. Low CO
3. Hypotension
4. LV failure
5. LV volume load
26
4 physiologic results of right to left shunts
1. Decreased pulmonary flow
2. Hypoxemia
3. LV Volume Load
4. LV dysfunction
27
6 things to avoid in right to left shunts
1. Sympathetic stimulation can increase PVR and reduce pulmonary blood flow
2. Decreased FiO2
3. Increased PCO2
4. Acidosis
5. Decrease in SVR
6. Decrease in PVR
28
Name 5 cyanotic heart defects
1. Tetralogy
2. Transposition
3. Truncus Arteriosus
4. Total Anomalous pulmonary venous return
5. Hypoplastic left heart syndrome
29
2 clinical findings associated with severe, long-standing cyanosis
1. Clubbing of the fingertips (hypertrophic osteoarthropathy)
2. Polycythemia
30
Why are we extremely careful not to allow any sort of air bubbles in IV tubing/syringes in patients with R to L shunt?
The shunt permits venous emboli to bypass the lungs and directly enter the systemic circulation
31
4 considerations related to anesthetic practice in patients with right to left shunt
1. Obstruction of pulmonary blood flow
2. Delayed uptake of inhaled anesthetics d/t bypassing pulmonary circulation
3. Judicious avoidance of air in lines
4. Increased PaCO2 and ETCO2 gradient
32
What is a major condition that prolongs transitional circulation?
Hypoxemia
33
Do we see any sort of affect from left to right shunts on inhalation induction?
No; There is a higher blood concentration of anesthetic in the pulmonary circulation which leads to a reduction in uptake, but this is nullified due to recirculation of pulmonary blood causing an increased uptake of anesthetic
34
3 Hemodynamic consequences of mixed shunts
1. Hypoxemia of varying degrees
2. Qp/Qs very dependent on PVR and SVR
3. Elevcated hct and hyperviscosity
35
4 Hemodynamic goals with mixed shunts
1. Adjust PVR/SVR for optimal Qp/Qs and oxygen saturations
2. Decreased FiO2 and Increased PaCO2 if Qp/Qs is high
3. Improve mixed venous saturation
4. Optimize tissue O2 delivery
36
2 examples of mixed shunts
1. Hypoplastic left heart
| 2. Truncus arteriosus
37
By what age does PVR reach near adult levels
6 months
38
At what point does PVR lead to a right to left shunt through DA and FO?
When PVR exceeds SVR
39
Why does PVR significantly decrease after birth?
Lung expansion (Incr. FRC) and oxygenation (Incr. Alveolar PO2)
40
9 factors that reduce PVR
1. No PEEP
2. Low airway pressures
3. Lung expansion to FRC
4. High Fio2
5. Respiratory and Metabolic Alkalosis
6. Low Hematocrit
7. Blunted stress response (Deep Anesthesia)
8. Nitric Oxide
9. Vasodilators
41
5 Pharmacologic Descriptors of Nitric Oxide
1. Selective pulmonary vasodilator
2. Endogenous and produces vascular smooth muscle relaxation and vasodilation
3. Delivered by ventilation to treat Pulmonary HTN
4. 20-40 ppm usually used
5. Rebound pulmonary htn can occur after discontinuation
42
What is the best way to alter PVR without making major changes to SVR?
Ventilation changes
43
PaO2 and PaCO2 goal to decrease PVR
PaO2 > 60mmHG
| PaCO2 30-35 mmHg
44
2 major factors that increase pulmonary output
1. Decreased PVR
| 2. Increased SVR
45
2 major factors that increase systemic output
1. Increased PVR
| 2. Decreased SVR
46
Why is a good premed important in pedi patients with a shunt?
To reduce distress so that we do not exacerbate symptoms and put us in a bad spot hemodynamically
47
How do we protect the lips from the TEE remaining in place?
Tegaderms over the lips!
48
NPO time for clear liquids?
2 hours
49
Describe NIRS (5)
1. Near infrared spectroscopy
2. Real time monitoring of tissue oxygenation
3. Value obtained is a reflection of underlying tissue
4. Used to assess brain O2 delivery
5. A 20% drop from baseline is considered significant and interventions need to be performed to improve this
50
Calcium Chloride concentration for pedi heart pts >10kg, <10kg
>10 kg: 100mg/mL
| <10kg: Diluted to 10mg/mL
51
Phenylephrine and Epinephrine dilution doses for pedi hearts (3)
1. 1 mcg/mL (<3kg)
2. 10 mcg/mL
3. 100 mcg/mL (>40kg)
52
What type of intubation do we normally perform for pediatric hearts?
Nasal = need magills!
53
Why do we use a small (wee) medline in pediatric hearts?
So that we do not have to use a ton of fluid to flush drugs, want to connect this to a proximal port
54
Is CVP in pediatric hearts always representative of right atrial pressure?
No, this is dependent on the type of defect present
55
When do we use steroids in pediatric heart patients?
Only if we go on pump to reduce the inflammatory response associated
56
4 maintenance drugs for pediatric hearts
1. Methadone 0.1-0.2 mg/kg
2. Rocuronium
3. Sevo
4. Sufentanil infusion
57
LR, Dopamine, Epinephrine, Milrinone and Sufentanil infusion rates in pediatric hearts
1. LR @ low basal rate based on patient weight
2. Dopamine @ 5mcg/kg/min
3. Epinephrine @ .05mcg/kg/min
4. Milrinone @ 0.5mcg/kg/min
5. Sufentanil @ 0.5mcg/kg/hr started after induction and foley in place, prior to TEE placement
58
Why do we always use the same pump set up in pediatric hearts?
To reduce the threshold for error in emergencies
59
6 other transfusions commonly used in pediatric hearts
1. TXA esp. in re-do
2. Prexedex @ 0.3-0.7 mcg/kg/hr
3. Nicardipine @ 0.5mcg/kg/hr up to 1mcg/kg/hr titrated at 0.5 mcg increments
4. Vasopressin
5. Norepinephrine
6. Alprostadil (PGE1) : Keeps PDA open
60
Why might we need to give FFP in pediatric heart patients prior to incision?
Low AT3 levels
61
When do we usually expect to administer platelets and cryo in pediatric heart cases?
After coming off cardiopulmonary bypass
62
How do we prepare blood for pediatric hearts?
Blood should be in the room and checked for quick administration if needed
63
How do we administer FFP if AT3 is low?
20mL/kg administered total.
10mL/kg administered IV.
10mL/kg given to the perfusionist.
64
How much heparin do we administer and what is our goal ACT in pediatric hearts?
300-400 units/kg heparin for an ACT >300 seconds
65
How does heparin work with AT3
Combines with AT3 to bind and inhibit thrombin, so if AT3 levels are low, then heparin is going to be less effective
66
5 considerations when going on pump for pediatric hearts
1. Dose midazolam
2. Re-dose NMB (roc)
3. Once perfusionist verifies you are at full flow, you can stop ventilation or flutter the lungs
4. Begin to cool the patient (reduction in cerebral and whole body O2 consumption by 5-6% for each 1 degree Celsius decrease in body temp)
5. Watch NIRs trend
67
What does it mean to "flutter" the lungs
High rate, low pressure allows for small tidal volume to prevent atelectasis
68
4 consideration when coming off pump for pediatric hearts
1. Temp > 35 Celsius (use a nasal and bladder temp, remember that nasal will get there quicker so base your goal of bladder temp)
2. Stable rhythm (pacemaker ready)
3. Good cardiac function assessed by cardiologist using TEE
4. Products ready? (2 platelets and 2 cryo or 3 plt, 3 cryo, 1 ffp for bigger cases such as hypoplastic left heart)
69
(4) Describe modified ultrafiltration (Muf) when coming off pump in pediatric hearts
1. Allows the bypass circuit to remain primed with pt blood volume and pump circuit volumes to be hemoconcentrated.
2. usually lasts 10-15minutes
3. Allows for greater hemoconcentration especially in children
4. Do not administer protamine during this time as we are still on pump
70
What is the usual dose for protamine with pediatric hearts?
1-1.5mg per 100 units of heparin, may sometimes have to re-dose, check act after administration
71
What is the rule of 4's for coming off cardiopulmonary bypass with pediatric hearts
pH 7.4
HcT 40%
PCO2 40mmHg
72
What device do we use to deliver nitric oxide?
NOXBOX
73
5 examples of volume overload lesions for pediatric heart patients
1. PDA
2. ASD
3. VSD
4. Atrioventricular septal defect/AV canal (AVC)
5. Truncus arteriosus
74
What patients is a PDA often found in?
preterm infants (10% of all CHD)
75
4 conditions that cause delayed functional closure of PDA
1. Preterm infants at risk d/t higher circulation of prostaglandin levels
2. Decreased degradation of PGE1
3. Increased production of PGE1
4. Diminished sensitivity to ductal constricting effects of oxygen
76
Who performed the first successful PDA ligation?
Dr. Robert Gross in 1938
77
3 conditions PDA can be associated with
1. Necrotizing enterocolitis
2. Renal Failure
3. Intraventricular hemorrhage
78
3 interventions to close PDA
1. Percutaneously in the cath lab by interventional cardiologist
2. Surgically closed in OR via left thoracotomy
3. Surgically closed in NICU on infants less than 1kg and ventilated
79
5 steps in the physiology of PDA
1. Initially high PVR after birth limits the shunt magnitude
2. After PVR decreases a left to right shunt develops that increases pulmonary blood flow
3. LV output must increase to maintain systemic blood flow
4. Increase LA pressure develops from increased PBF
5. Pulmonary artery hypertension can develop
80
What position is the patient placed in for closure of PDA
right lateral decubitus to allow for a left thoracotomy
81
During a thoracotomy for PDA closure, when can we expect some difficulty with lung ventilation?
during lung retraction
82
What nerve can be damaged with a left thoracotomy
left RLN
83
6 anesthetic considerations for PDA closure
1. Maintain CO
2. Avoid decreases in pvr:svr to maintain systemic blood flow
3. avoid increases in pvr:svr
4. 2 pulse oximeters
5. 2 large bore IVs at minimum
6. Upper and lower extremity blood pressure cuff.
84
How does an increased PVR affect pediatric shunts? Decreased PVR?
Increased PVR: can reverse shunt and compromise blood flow to the lungs
Decreased PVR: can increase the left to right shunt and reduce systemic blood flow
85
What is normal for opioid usage during PDA closure?
High dose such as 50-100mcg/kg
86
What type of IVF are normally used for PDA closure?
Dextrose containing
87
Describe preductal and postductal oximetry
Right hand is perfused by aorta and should have good flow (preductal)
Left hand and feet are perfused by mixed blood (postductal)
88
A patient has a >10% difference between the preductal and postductal oximetry, what could this indicate?
ductal dependent lesions or PDA present
89
What type of shunt is present with an ASD?
left to right, meaning this is an acyanotic defect
90
What percentage of PFO's remain patent after birth?
about 30%
91
What age group are PFOs present in about 50% of patients?
Children < 5 years of age
92
By what age are 15% of PFOs closed?
4 years of age
93
Where is the defect for ASDs?
in the intra atrial septum
94
What is the most common ASD?
Secundum Type
95
Which ASD is also known as an unroofed coronary sinus?
Coronary sinus defect
96
Which ASD can be associated with a cleft mitral valve?
Primum atrial septal defect
97
Which ASD can be associated with anomalous pulmonary drainage?
Superior sinus venosus defect
98
Which ASD is dependent on pvr:svr
Large, unrestrictive ASDs (<1mm), as small, restrictive ASDs have minimal flow
99
Where do we see volume overload in patients with ASDs?
RA, RV and LV
100
Which two ASDs are most commonly closed in the Cath lab
PFO and Secundum
101
What pediatric congenital heart defect can be closed by a pericardial patch?
ASDs
102
Two ways a large ASD can affect children
Slow growth and CHF
103
After what age does an ASD need to be closed surgically
After 2 years of age
104
When setting up the OR for a patient with an ASD, what are the usual CVOR drips we use?
LR, Dopamine, Epinephrine, Milrinone and Sufentanil
105
Describe the 5 anesthesia considerations for patients undergoing surgery for an ASD
1. Normal CVOR set up with drips
2. Sternotomy with CPB
3. Anticipate early extubation in OR or in ICU soon after arrival
4. Smaller doses of narcotics used
5. Muscle relaxant with reversal prior to transport
106
5 main goals for providing anesthesia to patients with an ASD
1. Maintain cardiac output
2. Judicious volume - patients are very susceptible to Right heart overload, especially the right ventricle
3. Watch for air in lines! - Don't want to cause a venous air embolus
4. Avoid decreases in pvr/svr (esp. with large VSD)
5. Avoid increases in pvr/svr (esp. with large VSD)
107
For a patient with a large VSD, what does increasing pulmonary blood flow do?
Reduces systemic oxygen delivery
108
Describe what a VSD is
An opening in the ventricular septum that allows communication between the right and left ventricles
109
What type of shunt is present with a VSD
left to right (acyanotic)
110
Describe small, restrictive VSD
large pressure gradient means there is not much movement between ventricles
111
Describe large, unrestrictive VSD
shunt is dependent on svr/pvr, similar to ASD
112
Which longstanding CHD will patients present with near systemic PA pressure?
Large VSDs
113
What is the most common CHD in children?
VSD
114
4 types of VSDs and which is the most common
1. Subarterial
2. Perimembranous (most common @ 80%)
3. Inlet
4. Muscular
115
Which type of VSD is located just below the pulmonary valve and may be associated with aortic insufficiency?
subarterial/subpulmonary/supracristal
116
Describe perimembranous VSDs (4)
1. Subaortic region of the membranous septum
2. Near or under septal leaflet of tricuspid valve
3. Just below the aortic valve
4. Commonly partially closed by tricuspid valve and septal tissue and has aneurysmal appearance
117
Which type of CHD can pulmonary and systemic venous congestion at rest develop due to increase in demand in CO?
VSD
118
How is systemic blood flow maintained in VSD
at the expense of high-volume load in right and left ventricle
119
Which type of VSD should we make sure to have a pacemaker available for post-op due to dysrhythmias being common?
Those near the AV bundle of His
120
How do a significant number of VSDs close in the first few years of life
spontaneously
121
Anesthetic considerations for patients with VSD (4)
1. Inhalation induction or IV tolerated well
2. Maintain CO (high dose narcotics = good)
3. If asymptomatic preoperatively and uncomplicated closure, consider lower opioid doses for early extubation
4. Symptomatic or CHF, high dose opioids for hemodynamic stability (vasodilator use common)
122
What disease process can be a major problem in patients with VSDs
Pulmonary hypertension, have nitric oxide available
123
What 3 congenital disease are AVSD/AVCs commonly associated with and which is the most common
1. Trisomy 21 (most common)
2. TOF
3. DiGeorge Syndrome
124
Describe the 3 types of AVSD/AVC
1. Incomplete/partial (usually primum ASD, MV cleft, no VSD)
2. Transitional (ASD, left and right av valves only partially separated, VSD small or moderate)
3. Complete AVSD (large septal defect, common av valve)
125
3 effects on cardiopulmonary circulation when a AVSD/AVC is present
1. Increased pulmonary blood flow (can reverse shunt if too high)
2. Increased pressure to right ventricle and pulmonary arteries
3. Volume overload to right and left ventricles (CHF)
126
What adjustments should we make during PA band placement for a AVC defect?
none!
127
At what age would you expect an AVC to be surgically closed?
3 months of age usually
128
6 anesthetic considerations for an AVC
1. Maintain CO (these kids have limited cardiac reserve, be careful with inhalation induction)
2. Maintain pvr:svr (severity of disease guides these)
3. Use reduced FiO2 or room air
4. Maintain PaCO2 35-40 mmHg
5. High dose narcotic to blunt increase in pvr/hemodynamic stability
6. Judicious sevo
129
Which rare CHD is associated with DiGeorge Syndrome?
Truncus arteriosus
130
What happens in Truncus Arteriosus
the fetal trunk fails to divide into the two great arteries
131
Which valve is the truncal valve considered to be in 60-70% of patients?
Tricuspid
132
Where do we see high blood flow in truncus arteriosus
pulmonary; surgical repair is done early to prevent irreversible pulmonary artery hypertension
133
How do we determine what type of truncus arteriosus is present?
Based on the source of pulmonary blood flow supply
134
What type of VSD with truncus arteriosus allows equal pressure in Right and Left ventricles
Large, nonrestrictive
135
What does the normal pvr decrease after birth cause in patients with truncus arteriosus?
High pulmonary blood flow and symptoms of CHF with mild cyanosis, eventually further decreases in pvr and increases in PBF comes at the expense of systemic blood flow and progressive metabolic acidosis develops
136
Where is the conduit placed for patients with truncus arteriosus?
RV to PA
137
What is the preferred method for surgical treatment of truncal valves?
Valvuloplasty
138
What is the post-op mortality rate for patients with Truncus Arteriosus?
5-25% (very high)
139
What is the best way to control PVR in patients with truncus arteriosus?
Mechanical Ventilation
140
Which type of induction should be considered in patients with truncus arteriosus?
High dose fentanyl with a NMB as opposed to inhalation induction
141
FiO2 goal for patients with truncus arteriosus?
<30%
142
Common dysrhythmia seen prior to going on pump in patients with truncus arteriosus
Vfib
143
3 ways to reduce PVR in patients with truncus arteriosus to increase pulmonary blood flow and reduce pulmonary HTN
1. Reduce the PaCO2
2. Nitric Oxide
3. 100% FiO2
144
What 2 specific anesthetic considerations do patients with DiGeorge syndrome require?
Irradiated blood products, supplemental calcium
145
3 descriptors of Coarctation of the aorta
1. More common in males
2. Discrete narrowing of the aorta
3. Often an isolated lesion, but can occur with other arch abnormalities
146
How are coarctations of the aorta classified
based on location to the ductus arteriosus (preductal, juxtaductal, postductal)
147
Describe the most common type of coarctation of the aorta (4)
This is a preductal COA
1. Presents commonly in neonatal period
2. Minimal collateral circulation below coa
3. Requires PGE to maintain ductal patency
4. Poor ventricular function, heart failure
148
Describe juxtaductal/postductal COAs (5)
1. Commonly found when > 1 year of age
2. Collaterals that supply flow below coa (supply spinal cord during cross clamp)
3. Better left ventricular functuion
4. Weak femoral pulses
5. Progressive acidosis
149
Severity of disease increases or decreases with age when it comes to COAs?
Decreases
150
The arterial saturation is ___ closer to the coarctation meaning what
The arterial saturation is __higher__ closer to the coarctation, meaning the right hand O2 sat will be greater than anywhere else in the periphery
151
When the PDA closes at about the second day of life, what happens to distal perfusion in patients with severe COA and how do we treat this?
Ductal closure results in near loss of distal perfusion and we can prevent this with PGE1 infusions to maintain the PDA
152
When the PDA closes at about the second day of life, what happens to distal perfusion in patients with less severe COA?
Less severe COA with ductal closure can result in diminished distal perfusion and left atrial hypertension
153
4 patient physiologic descriptors of a restrictive COA when the PDA is open
1. Pulses normal/weak
2. Post-ductal sats low
3. Good urine output
4. Not acidotic
154
4 patient physiologic descriptors of a restrictive COA when the PDA is closed
1. Pulses normal/absent
2. Post-ductal sats normal/poor trace
3. Oliguric
4. Acidotic
155
Infusion dose of PGE1 to maintain ductal patency
0.05-0.1 mcg/kg/min (0.01-0.05 mcg/kg/min @ stortroens site)
This medication is very specific for PDA, these are a direct smooth muscle relaxant, but you can get some variable pulmonary and systemic vasodilation.
156
What part of the heart has poor function with patients who have a COA
They have poor left ventricular function that may require inotropic support as they are injecting through a small opening
157
8 Anesthetic considerations for patients with COA
1. Slow, gentle IV induction (inhalation more tolerated in older children with collateral)
2. High dose narcotics/rocuronium
3. Maintain CO
4. Avoid increased SVR - already have issues ejecting through the COA
5. Maintain LV output (vulnerable to decreased contractility) - used to high after load
6. A-line on right arm
7. 2 pulse ox/2 pressures
8. Left thoracotomy
158
What type of environment do we want to maintain for pediatric patients undergoing intervention in the Cath lab?
a normal physiologic environment
159
Describe a gas challenge for pediatric patients in the Cath lab and what it looks for
This is used to determine the degree of pulmonary hypertension, pulmonary values are taken prior to intervention and then nitric oxide is used starting out at about 20 ppm, then pulmonary values are taken again.
If there are significant changes in the pulmonary numbers post intervention, this indicates that the patient has very reactive pulmonary vasculature
160
How does balloon or stent placement for aortic stenosis/pulmonary stenosis help the patient?
This helps increase distal perfusion
161
5 anesthetic considerations for pediatric patients in the cath lab
1. Light anesthetic conditions needed, the most stimulation is during the initial stick
2. Remifentanil run at 0.1-0.3 mcg/kg/min
3. Rocuronium, but not needed for diagnostic procedures
4. Sevoflurane @ < 1 MAC (use a BIS monitor)
6. Dopamine ready
162
When should we expect to give heparin in pediatric patients undergoing cath lab procedures
The venous and arterial sheath will be inserted into the groin, an initial blood gas Is taken and THEN we give heparin
163
4 complications associated with cath lab procedures
1. Dysrhythmias
2. HoTN
3. Rupture
4. Occlusion
164
What do we avoid in pediatric patients undergoing cath lab procedures to avoid increasing the risk of hematoma
Want to avoid coughing/straining post op
165
What symptoms (4) does an infant present with if Hypoplastic Left Heart Syndrome is missed?
Tachypnea, tachycardia, cyanosis, systolic murmurs
166
5 descriptors of hypoplastic left heart syndrome
1. Hypoplastic LV
2. Mitral stenosis or atresia
3. Aortic stenosis or atresia
4. Hypoplastic aortic arch
5. Duct dependent circulation
167
Describe the surgical palliation for hypoplastic left heart syndrome
In a series of 3 operations, the patient is converted to single ventricle circulation, causing the right ventricle to become the systemic ventricle. Pulmonary blood flow is then passively supplied from the SVC and IVC.
168
Describe the Norwood operation for hypoplastic left heart syndrome
This is performed in the neonatal period (1-2 days old). Main PA is disconnected from the RV, causing the aortic arch to arise from the pulmonary trunk. The pulmonary valve becomes the new aortic valve.
169
What is the shunt called when the subclavian artery is connected to the pulmonary artery for HLHS?
BT shunt creates pulsatile pulmonary blood flow
170
What is the shunt called when the Right Ventricle is connected to the pulmonary artery for HLHS?
This is called a sano, which violates the integrity of the RV but the patient gets better pulmonary blood flow
171
Are patients acyanotic or cyanotic post repair for HLHS?
Cyanotic
172
5 Anesthetic considerations for clamp on during COA repair
1. Heparin given (100 units/kg)
2. Short cross clamp time ideal (<30 minutes, but 15 minutes is best)
3. ACTs Q30min or surgeon preference
4. Cooled to 34 degrees
5. Cross clamp hypertension (Proximal perfusion pressure may be high, but distal could be low so may need dopamine to maintain distal perfusion)
173
4 Anesthetic considerations for unclamping during COA repair
1. Volume expansion (d/t HoTN) and increase ventilation (longer cross clamp time will lead to transient increases ETCO2 post clamp)
2. Prepare for post-op hypertension
3. LV hypertrophy expected for weeks
4. Sodium nitroprusside/nicardipine or beta blockers often with older children
174
Where should we place the A-line for COA repair surgeries?
Ideally right radial to allow uninterrupted pressures during cross clamp
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When should we expect ventilation issues during COA repair?
While the lung is retracted after a left thoracotomy
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How many pulse OXs and pressures do we need for COA repair?
2 of each
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What do we worry about in infants with COA after the PDA closes?
Profound metabolic acidosis
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What side effect do we have to worry about with Prostaglandin infusions in neonates?
Apnea, they most likely need to be intubated and mechanically ventilated while on the infusion
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Which arm will we have higher blood pressures in due to being more proximal to the stenosis in COA patients
the right arm when compared to the left leg
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Are we on or off pump for COA cases
off pump
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What other monitor is a good idea in COA repair during clamp times to make sure the brain is getting good perfusion?
NIRS
| remember a 20% drop is significant and indicates intervention is required
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What is the most common chromosomal abnormality
Down Syndrome (Trisomy 21)
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5 key characteristics of down syndrome
1. short neck
2. macroglossia
3. Mandibular hypoplasia
4. Atlantoaxial instability and ligamentous instability (C-spine abnormalities)
5. Hypotonia
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You are assessing a child with down syndrome prior to surgery, what organ system should we check extensively due to the high probability of a defect?
The Cardiovascular system, 40-50% of children with down syndrome have CHD
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4 most common CHD in children with down syndrome
1. AV canal (most common)
2. VSD
3. PDA
4. TOF
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Besides a CHD, what other major disease are children with down syndrome at high risk for?
pulmonary hypertension due to increased pulmonary vasculature reactivity
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Anesthetic considerations specific to children with down syndrome (5)
1. subglottic stenosis
2. upper airway obstruction
3. post extubation stridor
4. small/abnormal radial vessels, challenging to start lines
5. Bradycardia common with anesthesia
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Describe Catch 22 in regards to DiGeorge syndrome
1. Cardiac defects
2. Abnormal facies
3. Thymic hypoplasia
4. Cleft Palate
5. Hypocalcemia
6. 22 Q11.2 Deletion
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3 most common features of DiGeorge Syndrome
1. Cardiac Malformations
2. Speech Delay
3. Immunodeficiency
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3 most common CHD associated with DiGeorge Syndrome
1. VSD
2. Truncus Arteriosus
3. TOF
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3 instances in which DiGeorge Syndrome should be considered
1. Conotruncual abnormality
2. Neonatal Hypocalcemia
3. Features with Dysmorphic faces
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4 Facial features associated with DiGeorge Syndrome
1. Cleft Palate w/wo cleft lip
2. Small mouth
3. Low-set ears
4. Long face and hooded lips
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What must we make sure of with blood products and inserting catheters into children with DiGeorge Syndrome d/t thymic hypoplasia?
Strict aseptic technique with irradiated blood products
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What electrolyte should we anticipate replacing intraoperatively with DiGeorge patients?
Calcium
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5 dysmorphic features associated with Noonan Syndrome
1. Neck Webbing
2. Low set ears
3. Chest deformities
4. Hypertertelorism (wider than normal distance between 2 organs, in this case it's usually the eyes)
5. Short stature
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What is a common CV development in the first year of life in patients with Noonan Syndrome?
Hypertrophic cardiomyopathy
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What is the most common cardiovascular disease in noonan syndrome?
Pulmonary valve dysplasia or stenosis
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What are patients with noonan syndrome at high risk for during surgery?
Massive bleeding
199
Describe Marfan Syndrome (7)
1. Mitral valve prolapse
2. Aortic dissection
3. Retinal detachment
4. Fibrillin-1 mutation
5. Arachnodactyly (fingers and toes abnormally long and slender)
6. Near-Sightedness
7. Scoliosis
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What major disorder can occur spontaneously in patients with marfans syndrome?
Pneumothorax
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What 2 standard medications are used in aortic root dilation with marfans syndrome patients?
Beta blockers or angiotensin receptor blockers
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Describe Vacterl abnormalities (6)
1. Vertebral
2. Anal
3. Cardiovascular
4. Tracheoesophageal
5. Renal
6. Limb defects
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3 most common lesions in patients with Vacterl
1. ASD
2. VSD
3. TOF
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What does CHARGE Syndrome stand for
1. Coloboma of the eye (missing pieces of tissue in the structures that form the eye)
2. Heart defects
3. Atresia of the chonae (nasal passages)
4. Retardation of growth
5. Genital anomalies
6. Ear abnormalities
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What are the two most common cardiac effects associated with CHARGE syndrome?
Conotruncal and aortic arch abnormalities
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What are patients with CHARGE syndrome at high risk for anesthesia from?
High risk from cardiac defects and adverse airway events postop
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Besides CHD, what else is very common in children with CHARGE syndrome?
Upper airway abnormalities
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When do we expect a patient with HLHS to undergo bidirectional glenn placement?
At about 6 months of age
209
What connection is made during a bidirectional glenn surgery?
SVC is connected to the pulmonary arteries, creating a route of passive blood flow to the pulmonary supply from systemic blood flow
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What does pulmonary blood flow depend on with a bidirectional glenn?
The pressure gradient between SVC and atrial pressure, this is referred to as the Transpulmonary Gradient (want low pulmonary pressures)
211
What is an expected SPO2 in patients with bidirectional glenn?
mid 80's
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What does a fotnan operation establish?
Normalizes oxygenation and decreases ventricular volume overload by separating systemic and pulmonary circulations
213
Why is a fotnan operation not performed in infants?
Pulmonary blood flow is reliant on the Transpulmonary Gradient and infants have high PVR with small vessels
214
What connection is made in a fotnan operation and what happens to pulmonary blood flow?
IVC is connected to the PA, leaving pulmonary blood flow up to passive systemic flow from the IVC and SVC
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What does the fenestration in the fotnan operation allow for?
It allows for blood to be directed to the RA to maintain CO in the event of increased PVR
216
3 results of postoperative complications from increased systemic venous pressure post fotnan operation
1. Pleural effusions
2. Hepatomegaly
3. Protein losing enteropathy
217
What is the only "cure" for HLHS?
Heart transplant
218
During a Norwood procedure, what does decreased pvr cause? increased pvr?
Decreased pvr: hypotension d/t increased pulmonary blood flow
Increased pvr: Cyanosis d/t decreased pulmonary blood flow
219
What is the ideal vent mode for pedi patients post norwood procedure?
Spontaneously breathing with blender of room air
220
What temperature do we see in norwood patients due to the length of the surgery?
Profound hypothermia during bypass
221
Ideal induction method for norwood procedures?
High dose narcotic
222
What drugs do we need to make sure to have ready postop norwood procedure?
Inotropes d/t post-op myocardial dysfunction being so common
223
What do we expect bypass-wise for BDG (bidirectional glenn) surgery?
On or off pump, usually no cardioplegia used and inotropes are not often needed
224
What is the effect on blood flow with a BDG if PPV is being used?
Increased intrathoracic pressure causes a reduction of BGD flow
225
How can we position the patient for a BDG to increase the blood flow?
Head up
226
What is the postop PVR goal after fotnan surgery?
Low pvr, might need nitric oxide or milrinone
227
What are patients reliant on postop from fotnan surgery?
Preload
228
What are the hallmarks of children with fontan pysiology?
Lower CO at rest and Limited exercise tolerance
229
3 CHD classified as obstruction to pulmonary blood flow
1. Pulmonary stenosis
2. TOF
3. Pulmonary atresia (medical emergency)
230
What is the most common cyanotic CHD?
TOF
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2 chromosomal abnormalities most likely associated with TOF
DiGeorge Syndrome and VACTERL
232
4 heart malformations that combine to make a TOF
1. VSD
2. Overriding aorta (biventricular connection)
3. RVOT Obstruction (Pulmonary stenosis)
4. RVH (d/t RVOT Obstruction)
233
What is the most common TOF variant?
TOF w/ pulmonary stenosis
234
With a TOF, what is cyanosis a combination of?
Right to left shunt and VSD (determined by RVOTO and SVR)
235
What does a blue Tet spell indicate
severe pulmonary stenosis or RVOT obstruction
236
What are tet spells initiated by (3)
crying, feeding, painful stimulus
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Can tet spells occur under anesthesia
yes, this is possible d/t metabolic acidosis, increased PaCO2, catecholamines, surgical stimulation etc.
238
Which type of tet spell is a medical emergency
blue tet spells
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Management of blue tet spells (7)
1. urgent intervention
2. Sedation/analgesia/paralysis
3. Valsalva
4. Vasoconstrictors (Phenylephrine)
5. 100% O2 and hyperventilation
6. Sodium Bicarb
7. Fluid Bolus
240
What dysrhythmia frequent occurs in the first 24-48 hours postoperatively from complete TOF repair?
Junction ectopic tachycardia
241
Anesthetic considerations for TOF repair (4)
1. Good premed to prevent tet spell
2. Inhalation or IV induction
3. CPB needed for full repair
4. RV dysfunction and pulmonary regurg may be post op complications
242
Surgical positioning for TOF surgery
Thoracotomy if palliation with BT shunt or sternotomy for complete repair
243
What is your biggest friend in patients undergoing TOF repair to maintain CO?
Preload (10-15mL/kg albumin is normal)
244
What inotrope can worsen RVOTO by dynamic narrowing of the RVOT in TOF repair?
Epinephrine
245
What is an example of a parallel circulation CHD?
D-transposition of the great arteries (most common type)
246
Where does the aorta arise from in d-tga? pulmonary artery?
Aorta: Morphologic right ventricle (deoxygenated blood pumped to systemic circulation)
Pulmonary artery: Morphologic left ventricle
247
Anesthetic considerations for d-tga repair (5)
1. Maintain PGE1 to maintain PDA
2. High dose narcotic
3. Avoid Increased PVR (Hypercarbia, acidosis, hypoxemia)
4. After repair, dilated PA from pulm htn can lead to coronary artery compression
5. LV frequently noncompliant, monitor LA pressures to limit volume to LV
248
In d-tga repair, what is myocardial dysfunction post bypass from? (4)
1. Coronary air
2. Poor coronary transference
3. Poor myocardial protection
4. Poor LV function
249
3 examples of single ventricle lesions (complete mixing of blood)
1. Tricuspid atresia
2. Double inlet left ventricle
3. Unbalanced atrioventricular septal defect
