Test 2 Flashcards
Due to higher pressure in left heart
Blood flows back to right heart via ASD/VSD
Type of shunt
What is the result
Left to Right
Pulmonary HTN
Blood bypasses the lungs and flows through ASD/VSD
Type of shunt
Results in
Right to Left
Cyanosis
Types of simple left to right shunt
ASD
VSD
AVSD
AP window
Simple right to left shunts
Tetrology of Fallot
Pulmonary atresia
Tricuspid atresia
Ebstein anomaly
Complex shunts
Transposition of Great Arteries
Truncus Arteriosus
Double outlet right ventricle
Hypoplastic left heart syndrome
Secundum ASD causes
Left to right shunt
What hemodynamic alteration may worsen a left to right shunt
Increase in SVR
Most common congenital defect in children
VSD
VSD is what type of shunt
Left to right
Complete AV septal defect results in
Left to right shunt
Both atrial and ventricular components of defect and single common AV valve
Complete atrioventricular septal defect. AVSD
Blood flows from aorta to PA
Type of shunt
Patent ductus arteriosus
Left to right shunt
When does ductus arteriosus normally close
Within a few hours to few days after birth
Due to changes in pressures of the pulmonary vasculature
Name physiologic factor most responsible for closure of the ductus arteriosus after birth
Increased arterial oxygen tension (major factor)
Reduction in circulating prostaglandins
Foramen ovale is closes due to what type of closure
Mechanical closure
Shunt of PDA is what type of shunt
Left to right
With PDA what CV changes occur
Increased workload on L side of heart
LV hypertrophy
Increased PVR
Probable problem if pediatric patient has systolic and diastolic murmur
PDA
Preductal placement of pulse ox
Right hand
Postductal pulse ox placement
Lower limb
If pulse lost from lower limb during test clamp indicates what
Aorta inadvertently clamped
Preductal pulse ox location is index of what
Neonatal cerebral oxygenation
Postductal pulse ox in indicative of
Severity of right to left shunt
Where should arterial BP be measured in pt undergoing repair of PDA
Peripheral artery (femoral)
Post ductal
4 components of Tetrology of Fallot
Pulmonary stenosis
VSD
overriding aorta
RV hypertrophy
Tetrology of Fallot results in what type of shunt
Right to left
Cyanosis
Most common cyanotic CHD
Tetrology of Fallot
Tets spells occur when
There is and increase in right to left shunt
Decree of hypoxemia in tets spell depends on
Relationship between RV outlet tract obstruction and SVR that determines the degree of right to left shunt
To reverse shunt in tets spell need to
Increase SVR to reverse shunt
6 treatments for tets spell
100% 02
Hyperventilation
Increase preload
Sedation
Vasoconstriction (increase SVR)
Beta blocker to relax infundibular spasm and reduce HR
Surgical management of Tetrology of Fallot
Complete repair
Closure of VSD and RVOTO
Modified BT shunt
Modified BT shunt MOA
Conduit attatch in R subclavian to PA
Passive flow to lungs
Post of pulmonary blood supply is size of predominantly dependent on size of BT shunt
Too small
Too large
Small- low sat
Large- heart failure, pulmonary edema
Pulmonary blood flow is dependent on size of BP shunt and what
SBP
Greater BP=more flow to lungs = higher saturation
Which way does blood flow through VSD in Tetrology of Fallot
Right to left
Cyanosis
What pharmacological agent decreases right to left shunt
Why
Phenylephrine
Increases SVR to decrease shunt
Anatomy of transposition of great vessels
Aorta from RV
PA from LV
Ductal patency of DA is maintained after birth with
Prostaglandin 1 infusion
Ballon atrial septostomy
Most crucial part of successful outcome of arterial switch operation in transposition of great vessels
Coronary arteries connected to neo-aortic root
Arterial switch repair with transposition of great vessels occurs when
Early (2-3 weeks)
Common truncal calve and mixing of oxygenated and deoxygenated blood
Truncus arteriosus
Path of truncus arteriosus
Common arterial outlet for aorta and PA associated with single valve and VSD
Truncus arteriosus results in what if untreated
High pulmonary blood flow= heart failure and pulmonary HTN
Tx for truncus arteriosus
Surgery to separate PA from systemic circulation and close VSD
Path of hypoplastic left heart syndrome
Very small LV
Mitral and aortic valve stenosis/atresia
Hypoplastic aortic arch
Single ventricle
Pulmonary blood flow in hypoplastic left heart syndrome is from
LA via ASD to RA/RV
Systemic blood flow in hypoplastic left heart syndrome is from
RV to PA to aorta via PDA
At birth neonates with hypoplastic left heart syndrome present with what S/S
Tachypnea
Tachycardia
Cyanosis
Systolic murmur
Several surgeries are required to repair hypoplastic left heart syndrome. End result is
Single ventricle circulation
3 surgeries to repair hypoplastic left heart syndrome
Norwood
Bidirectional Glenn
Fontan
Norwood procedure occurs at what age
Days after birth
Bidirectional Glenn repair occurs when
6 months
Fontan procedure occurs when
1.5-3 years old
Norwood stage operation is what
Creation of neo-aorta
Placement of BT shunt (flow from R subclavian to PA)
Flow through BT shunt is dependent on what
Pressure
Is passive flow
Post Norwood blood supply to lungs is from where
BT shunt of Sano modification
From subclavian to RA
Norwood anesthetic considerations
High dose opiods
Avoid IJ venous access
Balance SVR and PVR
Sternum will remain open
Bidirectional Glenn shunt procedure
BT shunt taken down
Connection of SVC to PA
Fontan procedure
Connect IVC to PA
Pulmonary blood flow after Fontan comes from
Passive flow from SVC and IVC
Post op Fontan considerations
PVR must remain balanced
Inotrope (milrinone) often needed
Early extubation beneficial
How does FiO2 have an influence on PVR
Hypoplastic left heart syndrome
Hypoxia causes pulmonary vasoconstriction but systemic vasodilation
High FiO2 significantly reduces PVR and increases blood flow to lungs away from systemic circulation
Why is it dangerous to administer high FiO2 to HLHS patient
Decreases PVR steals blood away from systemic circulation = decreased cardiac output
Which do potent volatiles decrease more
PVR or SVR
PVR
Ways to decrease PVR
Increased FiO2
Hypocapnia
PVR is increased with what
PEEP
Acidosis
Hypothermia
Low FiO2
Why is phenylephrine used to reduce R to L shunt and increase L to R shunt
Increases SVR more than PVR
7 factors that increase PVR
Hypoxemia
Hypercapnia
Acidemia
Hypothermia
Atelectasis
Transmitted positive airway pressures (PEEP)
Stress response/stimulation/light anesthesia
Anesthesia for HLHS
Spontaneously breathing
FiO2 21%
Prostaglandin E1 infusion
Normal/high PaCO2
If PDA is undesired to remain open what do you do
Indomethacin
PDA ligation
Subacute Bacterial Endocarditis prophylaxis
Amoxicillin PO
Ampicillin IV/IM
Cefazolin IV/IM
Ceftriaxon IM/IV
Induction drug of choice for cardiac anesthesia
Why <1.5 MAC
Sevo
> 1.5 MAC slows HR and respiratory depression
CHD patients respond to bradycardia in what way
Reduced cardiac output
Hypoventilation
Hypercarbia
Hypoxia
All = RISE IN PVR
Sevo effect on SVR
Mil decrease
Young infants with severe CHD induction
High opioid (3-5mcg/kg fentanyl)
Pancuronium
Low dose Sevo/ISo
In what patients should N2O be avoided
Why
Limited pulmonary blood flow
Pulmonary HTN
Depressed myocardial function
Decreases cardiac output
Propofol should be avoided in what patients
Fixed cardiac output
Severe AS/MS
Causes severe hypotension
Nitric oxide MOA
Very specific pulmonary vasodilator
Results in pulmonary vascular smooth muscle relaxation
Cath lab usage of inhaled nitric oxide
Assess reactivity of pulmonary vasculature
Dose of inhaled nitric oxide in cath lab
20-40 ppm
Flolan MOA
Naturally occurring prostaglandin
Potent vasodilator (SVR and PVR)
Treatment for primary pulmonary HTN
Flolan is contraindicated in which patients
CHF due to severe LV systolic dysfunction
Medications to avoid in EP study
Lidocaine
Opioids
Volatiles
Dexmedetomidine
4 defects involved with tetrology of Fallot
VSD
RVOT obstruction
RV hypertrophy
Overriding aorta
Goals of anesthetic management of patient with tetrology of fallot
Avoid tets spell
Maintain IV volume and SVR
Avoid increases in PVR
Infant with tetrology of fallot. Which ABG parameter will not be changed
PaCO2 and pH will be normal
What agents might be selected to decrease shunt and increase O2 sat in tetrology of fallot patient with desaturation due to increased shunt
IVF
Alpha agonist (phenylephrine)
3 conditions that increase right to left shunt in tetrology of fallot
Acidosis
Hypercarbia
Hypotension
Should upper extremity BP be monitored in neonate with preductal coarctation of aorta be measured in R or L arm
Right radial artery
Best site to obtain ABG from neonate
Right radial artery bc preductal
Preductal oxygen saturation reflects
Cerebral oxygenation
Anesthetic concern for pediatric patient undergoing repair of VSD with significant pulmonary HTN
Avoid manipulations that may increase PVR
Hypoxia Hypercarbia Acidosis Hypothermia Atelectasis SNS stimulation Polycythemia
R to L intracranial shunt is present in patient with VSD with Eisenmengers. What alterations may worsen R to L shunt of VSD
Abrupt increase in PVR or decrease in SVR
Will R to L shunt slow or accelerate inhalation induction
Slow
Blood bypasses lungs
Will R to L shunt slow or accelerate IV induction
Accelerate
Don’t need lungs
will L to R shunt slow or accelerate inhalation induction
Accelerate
Rate of transfer from lungs to blood is increased
Will L to R shunt slow or accelerate IV induction
Slow
