Exam IV: Cong Hearts Flashcards
ASD (L to R)
Many types including _____ _____ _____ (____)
Patent Foramen Ovale (PFO)
ASD (L to R)
PFOs: Usually ____ _____; usually close soon after birth. However, ____% of all adults have an asymptomatic PFO.
not treated
30
ASD (L to R)
Usually need no specific anesthetic considerations EXCEPT ______ ______. (Why???)
bubble precautions
VSD (L to R)
Most common CHD in children. Several types: _______ most common
perimembranous
VSD (L to R)
restrictive (____ flow, _____ problematic), LV pressure > RV
low
less
VSD (L to R)
Nonrestrictive (____ flow, ____ problematic), LV nearly equals RV
high
more
VSD (L to R)
Severity and management dependent on defect ____, degree of ______, PVR (pulm) and SVR.
size
shunting
VSD (L to R)
decreased PVR leads to increased left to right flow, increased pulm blood flow (pulm steal), and finally _____ _____
systemic hypotension
VSD (L to R)
approx. ___% close by 1 year old
75%
PDA (L to R)
Remnant of fetal circulation - connects pulmonary artery to _____ _____
descending aorta
PDA (L to R)
usually closes soon ______ _____
after birth
PDA (L to R)
Fetal: ____ to _____ to descending aorta (d/t high PVR)
RV to PA
PDA (L to R)
after birth: RV to PA to _____ (d/t low PVR)
lungs
PDA (L to R)
large PDAs that remain open lead to increased pulm blood flow; must be _____ ______
surgically closed (ligation via left thoracotomy)
PDA (L to R)
intubated neonates: _____ _____?
bedside procedure?
PDA (L to R)
pre and post ductal ____ ____?
pulse oximetry
PDA (L to R)
only ____ ductal limb: R hand
pre
Pre-ductal: Area near aortic opening closest to the _____ ______
Probe to ___ hand.
Blood flows to upper extremities, coronary and carotid arteries.
Pre-ductal saturation measures arterial O2 after leaving the heart but ______ it reaches the _____
ductus arteriosus.
R
BEFORE
ductus
Post-ductal: Area near aortic opening which is distal from the _____ _____.
Probe to ____ _____ or ____ _____. (L hand pre- or post- ?)
Blood is sent to lower extremities, femoral arteries and renal arteries.
The post-ductal saturation measures arterial O2 after leaving the heart and _____ it has passed through the ductus arteriosus.
Pre-ductal SaO2 at least 3% above post-ductal = R to L ductal shunting.
ductus arteriosus
L foot or R foot
AFTER
TOF (R to L)
most common ______ defect
cyanotic
TOF (R to L)
4 features
RV outflow tract obstruction (RVOTO) (1)
RV hypertrophy (2)
Overriding aorta (3)
VSD (4)
TOF (R to L)
can be ____ to _____
mild to severe
TOF (R to L)
spasmodic narrowing (RVOTO) just below pulm valve (infundibulum) causing ______ episodes (“tet spells”)
hypercyanotic
TOF (R to L)
chronic hypoxemia causes _____ of fingers and toes
clubbing
TOF (R to L)
AIs: optimize ____ filling
RV filling (decrease PVR, increase preload, NL SVR, avoid tachycardia)
“Tet Spells”
Cyanosis (R to L shunt) dependent on _____ and ____.
RVOTO and SVR
“Tet Spells”
triggers: (exact mech unknown )
- crying
- feeding
- acidosis
- hypercarbia
- catecholamines
- surg stimulation
“Tet Spells”
crying causes _____ narrowing (increased RVOTO) leading to increased r to l shunt through VSD and then cyanosis
infundibular
“Tet Spells”
children learn to ______ to increase SVR
squat
“Tet Spells”
emergent intervention: increase SVR leads to increase _____ pressure, decrease R to L shunt (decreased cyanosis)
LV
“Tet Spells”
treatment of choice
phenylephrine (1 mcg/kg) bolus, repeat until BP up and SaO2 improved. may need infusion.
“Tet Spells”
____ _____ (____) to relax infundibular spasm
Beta blocker (propranolol)
TGA (Complex, Mixed)
_____ rises from the R ventricle; ____ arises from the L ventricle.
Aorta
PA
TGA (Complex, Mixed)
Cyanotic shunt with 2 circulations running _____ rather than in ____
parallel
series
TGA (Complex, Mixed)
Without a PDA or VSD, systemic circulation would have ____ _____
NO oxygenation
TGA (Complex, Mixed)
25% TGAs have a ____. If not, PDA is kept open with prostaglandins (PGE1) and/or surgical balloon septostomy done at birth.
VSD
TGA (Complex, Mixed)
Definitive repair: ____ _____ procedure (2 arterial trunks transected and re-anastamosed to correct position)
Arterial “switch”
TGA (Complex, Mixed)
______ ______ must also be transected/reconnected.
Coronary arteries
TGA (Complex, Mixed)
Once repaired, AIs theoretically ____ _____ than general population.
no different
HLHS (complex, mixed)
5 features
Hypoplastic L ventricle
Mitral stenosis/atresia
Aortic stenosis/atresia
Hypoplastic aortic arch
Ductal-dependent circulation
HLHS (complex, mixed)
_____ used to keep PDA open until surgical repair
PGE1
HLHS (complex, mixed)
Surgical goal: ____ _____ becomes systemic pump with passive pulmonary flow from ____ and _____
R ventricle
SVC and IVC
HLHS (complex, mixed)
3 stages
Norwood I
Norwood II (hemi-Fontan)
Norwood III (Fontan)
HLHS (complex, mixed)
When R ventricle begins to fail, ______ is only option.
transplantation
HLHS (complex, mixed)
AIs: Maintain CO with ______, ______. (Ketamine good choice d/t CV stability.) Keep ____ near baseline (75-85%) with NL to low TVs and low PEEP to maintain venous return.
hydration, inotropes
SaO2
Aortic Stenosis (Obstructive)
Several variants, but primary pathophysiology: Imbalance of ____ _____/_____ (decreased coronary blood flow with increased L ventricular workload), ____/failure.
O2 supply/demand
LVH
Aortic Stenosis (Obstructive)
Treatment varies with _____ and _____ at diagnosis.
severity and age
Aortic Stenosis (Obstructive)
Emergent ______ done for severe AS in neonates.
valvuloplasty
Aortic Stenosis (Obstructive)
AIs: maintain normal _____ to maintain supply/demand balance. AVOID _______!
HR
TACHYCARDIA (think about factors r/t perioperative infants and children)
Coarctation of the Aorta (Obstructive)
2 general classifications:
_____: pre-ductal, require PGE1 to maintain PDA, few collaterals, poor LV function (may be in failure), large gradient in pre-stenosis SBP (R arm) and post-stenosis SBP (L leg)
______: good collaterals, better LV fxn
Neonatal
> 1 year old
Coarctation of the Aorta (Obstructive)
often have ____ after repair
HTN
CPB:
No peds circuits available. Children prone to ______ & ______ _____ while on bypass.
hemodilution and dilutional coagulopathies
Ex: Example: 3 kg, EBV: 270 mL, 350 mL priming volume = >100% dilution
CPB:
Children respond well to _____. No lactate and dextrose (to minimize _____ _____).
colloids
metabolic acidosis
CPB:
Most centers use _____ cannulation (aorta + SVC + IVC)
bi-caval
CPB:
_____ heparinization
heavy
CPB:
systemic _____ as low as ____
cooling
22 C
CPB:
when flow is established, aortic cross clamp, then cardioplegia, and finally ______
asystole
CPB:
after repair, de-airing, _____ removed, myocardial reperfusion with slow rewarming and then correct labs
clamp
CPB:
Separation: T-burg w aortic vent, TEE, treat hemodynamics and dysrhythmias, reverse heparin (______)
protamine
CPB:
Post-op: Mild hypothermia, poly-pharmacy, monitor bleeding, sternum may ____ _____.
remain open
CPB:
Shorter bypass times and increasing age = ____ _____
better outcomes
Pre-op Eval for Non-Cardiac Surgery
- Identify CHD and comorbidities
- Prior repair/anesthesia/hospitalization history
- Last CV visit/ECHO/EKG/CXR/MRI - get interpretations on chart
- Discuss CV symptoms (tachypnea, dyspnea, tachycardia), feeding (FTT), exercise tolerance.
- Document usual RA SaO2 and DOS SaO2. (Definitive repairs: N = >95%. Palliatives: N = 75-85%)
- With aortic arch abnormalities, check upper and lower BPs.
- Look for edema, clubbing, cap refill.
- Auscultate for murmurs.
- Labs depend on CHD (CBC, FBP, coags).
Sub-acute Bacterial Endocarditis (SBE) Prophylaxis
2007 (current) AHA Guidelines: Most post-surgical CV patients do NOT need SBE prophylaxis. Consult cardiologist and consider SBE prophylaxis for the following:
- Prosthetic valves
- History of endocarditis
- Unrepaired cyanotic CHD (includes palliatives)
- Prosthetic devices/materials placed within last 6 months
- Transplant patients with valve pathology
Sub-acute Bacterial Endocarditis (SBE) Prophylaxis
Tx of choice: _____ and if allergic use ______ or ______
PCN
cephalosporin or clindamycin
Perioperative Considerations
Hypo_____: Must consider specific defect and identify cause.
Hypotension
Perioperative Considerations
_______: Due to chronic hypoxemia. ↑ viscosity/sludging leads to decreased organ perfusion & ↑ risk of thrombotic events. Hydrate well, de-bubble all lines (consider filters), normovolemic hemodilution (?) for Hct > 65%.
Polycythemia
Perioperative Considerations
Tet spells: Common during induction (stress). Uncommon with non-cardiac procedures during GA. Avoid ______, _______, _______ (maintain SVR).
hypotension, hypovolemia, vasodilation
Perioperative Considerations
Heart Failure: In infants, usually d/t ventricular _____, _____, or obstructive ______.
overload, regurg
lesions
Perioperative Considerations
_____ _____: Chronic hypoxemia, shunting, ↓ coronary perfusion, ↑ blood viscosity
Myocardial Ischemia
Perioperative Considerations
Pulmonary Hypertension: Common with _____ _____. May be fixed or reactive. “Crisis” leads to arrest (severe R to L shunting). Avoid _____ ____: Acidosis, hypercarbia, hypothermia, hypoxemia, light anesthesia, pain. With known PAH history, in-depth risk/benefit analysis is essential.
unrepaired CHD
known triggers
Perioperative Considerations
Paradoxical Air Embolus: Mainly with R to L shunts and increased R side pressure. ______ precautions!!!
Bubble
Perioperative Considerations
Dysrhythmias: Any agent or technique can cause. Must know ____ _____ to avoid biggest risks. (Ex: Tachycardia is lethal in aortic stenosis.)
CHD pathology
Perioperative Considerations
Anticoagulation (AC): Dilemma - Risk of surgical bleeding vs. risk of thrombotic event. Lack of specific guidelines. Generally: For atrial arrhythmias, ACs should be stopped ___-____ _____ pre-op. For prosthetic valves, thrombus risk is ____ if ACs stopped.
Can be admitted for pre-op heparin infusion or ASA therapy substituted. ACs should be restarted ___-___ ____ post-op.
1-2 weeks
high
1-3 days
Perioperative Considerations
Pacemakers: Always consult with ______. Have magnet in the room to enable asynchronous pacing (if pacer malfunctions d/t interference). Back-up pacing and ______ must be available. Should be evaluated and reprogrammed post-op.
cardiologist
chronotropes
Perioperative Considerations
Eisenmenger Syndrome: _____ _____ vascular disease leads to shunt reversal with severe hypoxemia. Uncommon now d/t better surgical repairs early in life. ____ life expectancy; most die from _____ ____ ______. “…overall poor prognosis and extremely high risk of untoward events…” (Miller-Hance, p. 546).
Irreversible pulmonary
Poor
sudden ventricular dysrhythmias
Perioperative Considerations
Post-transplant: Delayed compensatory responses, respond poorly to indirect meds. ↑ HR d/t loss of _____ tone. Immunosuppressants can cause drug interactions, renal, hepatic, hemodynamic problems. STRICT _____ _____!
parasympathetic
ASEPTIC TECHNIQUE
