Exam 1 Flashcards
Pediatrics (202 cards)
1
Q
ASD is what type of shunt?
A
Left to Right
2
Q
An enlarged atrium can cause
A
Atrial Dysrhythmias
3
Q
What is the most common site for an atrial septal defect?
A
Fossa Ovalis (Ostium Secundum ASD)
4
Q
What is another type of ASD?
A
A patent foramen ovale (PFO)
5
Q
In an ASD, LA & RA pressures are relatively
A
Low, meaning the gradient is usually low
6
Q
With a VSD, a small/ restrictive defect results in a
A
Large Pressure Gradient
7
Q
With a VSD, a large/unrestrictive defect, the direction of the shunt is
A
Dependent on the relative PVR & SVR
8
Q
When does the shunting occur in a VSD?
A
During systole
9
Q
What is the most common site for a VSD?
A
The middle of the ventricular septum (perimembranous VSD)
10
Q
What is the most common congenital defect in children?
A
VSD
11
Q
VSD is associated with
A
Downs, VACTERL & CHARGE
12
Q
What is the physiologic consequence of the VSD?
A
It is a function of the pressure gradients between the RV & LV, which are dependent on PVR & SVR
13
Q
What happens if the VSD is large?
A
The RV & LV pressures equalize and the PVR & SVR determine the direction of blood flow
14
Q
What should be avoided when caring for a VSD?
A
Avoid situations that will decrease PVR or increase SVR, as both will worsen pulmonary congestion, increasing shunt flow
15
Q
Positive pressure ventilation will_____PVR; Volatile agents will _____SVR
A
Increase; Decrease
16
Q
Which 2 shunts can cause paradoxical embolism during Valsalva maneuvers?
A
ASD & VSD
17
Q
What can happen post-repair of a VSD?
A
Arrythmias due to electrical pathway
18
Q
Prolonged exposure to high pulmonary blood flows & systemic arterial pressures can cause
A
Pulmonary vasculature remodeling
19
Q
PVR increase can cause pulmonary
A
HTN
20
Q
What is the physiology of AV canal defect?
A
There is communication between all 4 chambers and abnormalities of AV valves
21
Q
What type of shunt is an AV canal defect?
A
Left to Right, leading to an increase in pulmonary blood flow
22
Q
What type of cardiac lesions cause right to left shunts?
A
Tetralogy
tricuspid
Truncus
Total
Transposition
23
Q
What type of shunt can cause a reversal of flow when pulmonary HTN is prolonged?
A
Eisenmenger Syndrome
24
Q
Tetrology of Fallot is defined by what 4 things?
A
(Underdevelopment of the right side of the heart)
- VSD
- RVOTO (pulm. atresia)
- Overriding aorta
- Right ventricle hypertrophy
25
What is the most common cyanotic lesion?
Tetrology of Fallot
26
How do you medically manage Tetralogy of Fallot?
Minimize the RIGHT to LEFT shunt by
Increasing SVR
Decreasing PVR
Maintain Contractility & HR
Increase Preload (fluids)
27
With Tetralogy of fallot, the degree of RVOT obstruction strongly correlates with the
Amount of Shunt
28
What happens when the RVOTO is increased?
More deoxygenated blood is shunted through the VSD and out into the Aorta
29
How does the body compensate for a RVOTO?
Erythropoiesis, even though this leads to polycythemia & an increase risk of thromboembolism and stroke
30
When do tet spells occur?
When there is an increase in sympathetic activity; this causes an increase in myocardial contractility, which causes the RVOTO to spasm
This causes shunt to flow through VSD & there is an increase in RIGHT to LEFT shunting, leading to hypoxemia
31
How will the child compensate for a Tet spell?
Squat, which increases intraabdominal pressure, which will increase RV preload, SVR and blood flow through the RVOTO
32
Mapelson circuits have no
CO2 absorber
33
Which Mapelson circuit is best for spontaneous breathing? Controlled ventilation?
A; D
34
Evaporative water loss per kilogram of body weight is
Inversely proportional to age
35
What can result from hypothermia?
Metabolic acidosis due to non-shivering thermoregulation (brown fat metabolism)
36
In the preterm neonate, it is best to avoid
Administration of high inspired FIO2, as this can cause retinopathy of prematurity
37
In the neonate, what is decreased due to immaturity of the heart?
Decreased cardiac compliance
Decreased active tension along Frank Starling curve
Decreased augmentation of CO (increased end diastole)
Decreased tolerance to increased afterload
38
In the renal system, what starts to occur in the first few DAYS of life?
Increase in systemic arterial pressure and renal vasculature resistance decreases, increasing renal blood flow & GFR
39
Neonates have low GFR due to
High renal vascular resistance
40
The chest wall compliance in the infant is
High and lung compliance is low
41
Which type of diaphragmatic fibers are present in the infant?
More Type 2, which fatigue easily
42
Since the BBB is immature, this can lead to
Higher side effects such as seizures from specific medications
43
What are the risk factors for postoperative apnea?
General
Spinal
Regional
Sedation
Hx prematurity
Postconceptual age<60 weeks
Hx Apnea
Hx Bradycardia
Hx Anemia
44
Anesthesia results in end-expiratory lung volumes (FRC) to
Decrease to the point of airway closure, resulting in alveolar collapse and atelectasis
Muscle relaxants decrease FRC, leading to more collapse
45
How should an infant be positioned to optimize airway?
Blanket roll under shoulders
46
Hyperextension of the atlanto-occipital joint can
Produce airway obstruction
47
Prostagladin E1 administration maintains
Ductal patency & pulmonary blood flow in neonates with pulmonary atresia
48
What are cardiac lesions that depend on PDA to provide aortic blood flow?
Hypoplastic left heart
Severe Neonatal aortic stenosis
Interrupted aortic arch
49
What are cardiac lesions that depend on PDA to provide pulmonary circulation
Pulmonary Atresia
ToF
Tricuspid Atresia
50
What kind of shunt is needed for a pulmonary atresia?
Left to right, which can be provided by a PDA
51
What are stimulants that will maintain a PDA?
Hypoxia
Hypercarbia
Hypothermia
52
What will stimulate a PDA to close?
NSAIDs
Increase in PaO2
53
Single ventricle cardiac defects depend on a
PDA to maintain blood flow to the aorta or pulmonary circuit
54
In the neonate, the spinal cord (conus medullaris) ends at
L3 and dural sac ends at S3-S4
55
Dehydration is best assessed by
Weight
56
Radiant, infrared heat lamps can cause
Thermal burns, but doesn't produce retinal damage
57
All infants under 60 weeks postconceptual age should be
Admitted for 24 hours postoperatively and monitored for post-op apnea & bradycardia
58
The risk of post-op apnea is inversely related to
Gestational age
59
The initial transfusion of blood should start at
10-15mL/kg
60
Most infants can tolerate a HGB of
6-10
61
The goal of transfusion therapy in peds is to maintain
Adequate CO & oxygen carrying capacity
62
What is the blood volume for a preterm & full term infant?
90-100
80-90
63
Induction for the infant is
Quicker due to a higher cardiac output that distributed to Vessel Rich group faster
64
A 10mL/kg transfusion will increase the HGB by
1-2 g/dl
65
What is the CSF fluid in infants?
Higher volume and faster turnover, requiring a higher dose of spinal anesthesia
66
What is the time line of closure of the ductus venosus, foramen ovale & ductus arteriosus?
Ductus venosus- Minutes
Foramen Ovale- Days
Ductus Arteriosus- Weeks
67
The ductus venosus allows
Oxygenated blood to enter IVC
68
The ductus arteriosus allows blood to
Bypass lungs by shunting blood from the pulmonary artery to aorta
69
The foramen ovale allows blood to flow between the
Right & Left atria, bypassing the lungs
70
With cyanotic heart defects, induction is
Slower, but IV induction is faster
71
A continuous machine like murmur is best heard at the
Upper left sternal border during auscultation of a PDA
72
In utero the ductus arteriosus acts like what type of shunt?
Right to left due to high PVR
73
In TofF, the goal for anesthesia is to
Maintain or increase SVR to enhance pulmonary blood flow & improve oxygenation
avoid hypovolemia
minimize mean airway pressures
74
How is the foramen ovale closed?
There is an increase in afterload & decrease in pulmonary vascular resistance
75
ToF is the most common
CYANOTIC defect
(VSD-acyanotic)
76
High oxygen will create a
Low PVR
77
How can you raise PVR?
Increase CO2
Mild acidosis
Low FIO2
78
The motor cortex is
Unmylenated and poorly developed util 2
79
The sensory cortex is
Mylenated at birth, but nerves are poorly developed
80
Non-shivering thermogenesis is inhibited by
IA, BB, Fentanyl & Propofol
81
What is the best way to maintain body temperature
Increase OR temperature
82
HOTN in a newborn is a SBP less than
60
83
What should be done after passing the ETT
Apply 20cm H2O and listen for a glottic leak
84
The length of tube in an infant less than 1 is
5-9 cm
85
What is the equation for Vd?
Dose administered divided by plasma concentration
86
VD is used to calculate
Loading dose
87
What are water soluble drugs?
Morphine
Meperidine
Midazolam prior to admin.
Muscle relaxants
88
What are lipid soluble drugs?
Propofol
Etomidate
ketamine
Fentanyl
Midazolam after admin.
BB
89
Oral dose Midazolam
0.25-0.75 mg/kg
90
IV dose midazolam
0.05-0.1mg/kg
91
Intranasal dose of Midazolam
0.2
92
Ketamine doses oral/nasal/IM
Remember 5 for all
93
Intranasal dose of Precedex
0.1-0.4mcg/kg
94
When should Desflurane be avoided?
Asthma, reactive airways
Can cause laryngospasm
95
Doses of what drugs need to be increased due to increased volume of distribution & metabolic rate?
Succs
Propofol
Ketamine
96
Acute use of sedatives will
Decrease MAC
Chronic use has no effect
97
Infant dose of propofol?
2.5mg/kg
98
How can injection pain be reduced?
Lidocaine, Ondansetron, slow injection or larger IV
99
NBM are highly
Ionized with a low lipophilicity
100
NMJ is
Immature at birth, with a slow ACh release
Fetal ACh (with gamma subunit) is more sensitive to nondepolarizing agents
101
The diaphragm is
Less affected by NMB than peripheral muscles in preterm
102
The fetal receptors are opened
Longer, allowing for sodium to influx & increasing depolarizing potential
103
Neonates deplete
ACh vesicles faster
104
Polar drugs needs a
Larger dose due to Vd
105
Succinylcholine is limited to
Emergencies due to increased risk of elevated potassium, laryngospasm treatment & for RSI
106
Succinylcholine is contraindicated in
MH & those with muscle diseases
107
The best site to monitor train of four is
Adductor pollicis, which is more reflective of diaphragmatic recovery
108
A negative inspiratory force of _______ correlates with adequate ventilatory reserve
-32
109
Fentanyl IV dosing
0.5-1.0mcg/kg
110
Morphine IV dosing
0.05-0.1mg/kg
111
EMLA cream can cause
Methemoglobinemia (prilocaine) risk
112
What is the definition of laryngospasm?
Reflex glottic closure due to superior laryngeal nerve stimulation
113
Second dose of Succs can cause
Bradycardia
114
Increased PO2 will result in the production of
Bradykinin, which further causes vasoconstriction, leading to ductus venosus closure
115
The ductus arteriosus is dependent on
Oxygenation
116
The ductus arteriosus will cause left atrial pressure to
Increase
117
The foramen ovale only opens
Right to Left
118
What causes the foramen ovale to close?
Increase pressure in left atrium
119
What other medication will close a PDA?
Endomethacin
120
The heart rate is the primary determinant of
CO and SBP
121
The neonate myocardium lacks
Contractile elements to adjust contractility and stroke volume
122
The best way to support BP is to
Increase HR
123
In the setting of hypovolemia & bradycardia,
Epinephrine is the choice of drug
124
What should be done if HR is less than 100 and the RR is ineffective?
Start PPV with Room Air
125
Why is the pulse ox administered to the right hand?
Indicative of Cerebral perfusion
126
Massive transfusion can cause
Alkalosis
Hypothermia
Hyperglycemia
Hypocalcemia
Hyperkalemia
127
Drugs that depend on redistribution into the muscle tissue have a
Longer duration of action due to less fat & muscle tissue
128
Midazolam can cause
Sever HOTN due to decreased clearance
129
What is the predominant serum protein in fetal blood?
Alpha-fetoprotein
130
Normal GFR is achieved at
8-24 months
131
Normal Tubular function is achieved at
2 years
132
In the neonate & premie, the MAC is
Lower
133
In regards to SEVo, MAC for 0-6 months is
Higher
134
Stress is likely to cause
Bradycardia, which reduces cardiac output
135
When is phenylephrine a bad choice
To a neonate since they cannot increase contractility to overcome elevated afterload
136
The size & direction of the shunt are dependent on
Ratio of PVR to SVR
Pressure gradients between the cardiac chambers or vessels
Compliances of the cardiac chambers
137
A left to right shunt causes oxygenated pulmonary venous blood to
RETURN directly tot he lungs instead of being pumped to the body
138
A left to right (body to lung) shunt with cause a
Decreased systemic blood flow
Low CO
HOTN
Increased pulmonary blood flow
Pulmonary HTN
RVH
139
Which ventricle is dominant inutero?
Right ventricle
140
The neonatal heart is more reliant on
Calcium for contraction
141
Anatomic shunts are
Connections that allow communication from one system to the other (atria, ventricles, greater vessels)
142
Physiologic shunts results from
Relative pressure gradients
143
A murmur is a sound of
Turbulent flow through a shunt
144
In regards to a PDA, during diastole, blood continues to flow from
Aorta to pulmonary artery, which is called a diastolic runoff, which can lead to pulmonary over circulation
Left ventricular hypertrophy and dilation over time
145
Why would you see ST elevation if you give a PDA patient 100% FIO2?
It is a sign of heart strain since high oxygen concentrations will cause pulmonary vasodilation, making the Left to Right shunt worse (stealing from coronaries)
146
With ASD, shunting occurs during
Diastole
147
Atrial shunting will cause volume overload in the
RA
RV
LA
148
A reduction in glucuronyl transferase means metabolism of what drugs is decreased?
Tylenol & Morphine
149
MAC peaks at what age?
2-3 months
150
Why is the duration of action of muscle relaxer prolonged?
Immature metabolism & clearance
151
Rocuronium has mild
Vagolytic properties, and you may see a small increase in HR
152
Which nondepolarizer is the only one that can be given IM?
Roc
153
Vecuronium has active
Metabolites, which may indicate a longer duration of action. Vec is considered a long acting agent in this population
154
Pancuronium has a strong vagolytic effect that may cause
HTN, increasing the potential for blood loss as well as intracerebral hemorrhage
155
Apnea of prematurity is classified as a pause in breathing for
More than or equal to 20 seconds or shorter pauses accompanied by bradycardia &/or desaturation
Avoid hypothermia
Do gently stimulate
Treat with Caffeine or Theophylline
Should be apnea free for 5-7 days
156
Neonates have limited _______reserve
Preload
157
Neonates have increased _______dependence
Intraventricular
158
What substances decrease PVR?
ACh
histamine
Bradykinin
Prostaglandins
B-adrenergic catecholamines
Nitric Oxide
O2
159
Exposure of pulmonary vasculature to systemic arterial pressures & high flow
Large VSD
160
Exposure of pulmonary vasculature to high flow (without increased oressure)
Large ASD & PDA
161
A Qp:Qs ratio =1 means
Normal
162
A Qp:Qs ratio >2 means
Significant Left to Right Shunt (more blood is going to the Lungs)
163
A Qp:Qs ratio <1 means
Right to Left shunt (blood is bypassing the lungs)
164
Emergence delirium is characterized by
Post-op agitation, characterized by restlessness, crying, moaning, incoherence & disorientation
Last 45min
165
How can you prevent emergence delirium?
Propofol
Fentanyl
Precedex
Pre-op analgesia
166
What are ineffective ways of managing emergence delirium?
Midazolam
5-HT antagonists
167
What are potential causes of emergence delirium?
Rapid emergence from SEVO or DES
Neuroexitability
Rapid awakening in unfamiliar area
Noisy, Stress during induction, Pain, Hypoxia
Airway obstruction
Anesthesia duration
Pre-op anxiety
168
Pre-Op IVF is typically avoided
In those <10years
169
A cold OR will
Increase caloric intake & fluid needs
170
What is the TBW of a preterm infant
~80%
171
Preterm infants have a higher risk of apnea if
HCT is <30%
172
Crystalloid replacement is?
Colloid replacement is?
3:1
1:1
173
When should you consider PRBC?
When blood loss >/= allowable
174
Blood flow of the foramen ovale is from
Right to Left
175
The ductus arteriosus protects the lungs against
Circulatory overload
Allows right ventricle to strengthen
Carries medium oxygen saturated blood
176
After birth the left side of the heart will
Have an increase in pressure & the right side will weaken
177
Hypothermia can predispose the infant to
Metabolic Acidosis
Impaired peripheral perfusion
Increased risk of infection
Coagulation abnormalities
Reduced drug clearance
178
Neonates have a high affinity for
O2, which causes a left shift on the curve
Tissues receive less oxygen
This is until 6 months of age
Makes them more susceptible to hypoxia
179
What NMB is often preferred?
Cisatracurium because it doesn't rely on the kidneys for metabolism or excretion
Metabolized by Hofman elimination
180
Neonates will often exhibit ______on tetanus
Fade
181
Large bolus of Atracurium is associated with
Histamine type reaction such as erythema & bronchospasm
182
The right arm for BP monitoring is
Preductal
183
Preductal arterial saturation should be
Above 85% using peak inspiratory pressures below 25cm H2O & allowing PaCO2 to rise to 45-55mmHg
184
Hyperglycemia in the preterm infant is
Neuroprotective
185
Oral medications can be delayed due to
Delayed gastric emptying
186
Drug absorption is affected by
Molecular weight
Ionization
Lipid Solubility
187
There is a risk of hepatotoxicity with prolonged high doses of Tylenol due to
it being metabolized by Conjugation (Phase 2)
188
Moderated, Super & extensive fluid replacement for dehydration
10-20
30
40-80
189
neonates have impaired sodium
Retention & glucose excretion
Decreased bicarb reabsorption
Poor urine concentrating/diluting ability
190
For emergence delirium, give
Propofol on emergence as well
IV midazolam at emergence
191
What is the liter amount of PEDs reservoir bags
0.5-2L
192
With mask induction, the patient should be
Spontaneously breathing
193
Neonate & Infant size IV
24G
22G
194
ETT cuffed equation
Age/4 + 3.5 (tube diameter)
195
ETT uncuffed equation
Age/4 +4 (tube diameter)
196
Histamine release will decrease
SVR, worsening a Right to Left shunt
Lower SVR makes it easier for blood to bypass the lungs
(avoid morphine, meperidine & atracurium)
197
Ketamine will increase
SVR and reduce shunting
198
How do you treat a Tet spell in pre-op?
100% FIO2 (reduce PVR)
Fluids
Increase SVR with Phenylephrine
Decrease SNS stimulation
Deepen anesthetic
BB (esmolol)
Avoid inotropes
Knee to chest
199
For a single ventricle, O2 sats should be
75-85%
Sats will tell you how much blood is going to the lungs
200
Hypoplastic Left Heart Syndrome is characterized by
Small LV
Mitral & aortic Atresia
Hypoplastic Aorta 9ascending & arch
ASD
201
When balancing Qp:Qs, the goal is to ( in single ventricle)
Keep SpO2 75-85%
PaCO2 40%
PaO2 40
HCT 40
202
Infant formula, non human milk or light meal should be NPO for
6 hours
