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59 Cards in this Set
- Front
- Back
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Shunts |
Abnormal pathway that leads to an increase or decrease in pulmonary or systemic blood flow* flow direction is pressure dependent |
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Shunts and pulmonary blood flow |
Increased blood flow resulting in a volume or pressure overload to the pulmonary circulation (VSD, ASD, PDA, AVC, Truncus) Decreased blood flow - resulting in relative inability to oxygenate blood (HLHS, TOF, Tricuspid Atresia) |
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Shunts QP/QS=
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Sat (aorta) - Sat (SVC) / Sat (pulm venous) - Sat (PA) |
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Obstructive lesions |
Obstruction to blood flow due to a supravalvar, subvalvar, or primary valvular abnormality. increased ventricular workload and relative reduced circulation distal to obstruction - NO FLOW NO GROW |
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4 Main Problems associated with CHD |
Chronic Hypoxemia, CHF, Arrhythmias, Pulmonary Disease |
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Cyanosis |
Cyanosis occurs most commonly in lesions where pulmonary blood flow it anatomically decreased (TOF) mixing of systemic and pulmonary blood flow (single ventricle) |
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chronic Hypoxemia different from acute hypoxia |
Chronic - Disrupts all major organ systems. CVS, polycythemia, decrease cardiac reserve, myocardium replaced by fibrotic tissue, increased epi levels and sympathetic tone
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Chronic Hypoxemia |
Polycythemia- viscosity - think - stroke limits blood flow- fatigue, headache Rx- Short NPO, IV rehydration, Phlebotomy (>Hct 65%) Abnormal Hemostasis |
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Chronic Hypoxemia |
Growth - nl 1/3 metabolism devoted to growth - need increase caloric intake CNS - delayed neurologic development, brain abscess, DHCA |
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CHF |
Common with shunts lesion resulting in increased pulmonary blood flow (VSD) Obstructive lesions that stress the ventricle past its capacity to pump effectively (AS) |
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CHF symptoms |
Diaphoresis, Tachypnea, Poor feeding, Failure to thrive, and Recurrent Resp infection |
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Ohm's law |
I (current) = V (electromotive force) / R (resistance) CV physiology Q (blood flow) = P (Pressure drop across vascular bed) / R (resistance in vascular bed) |
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Poiseuille Relationship |
Small radius higher resistance - less blood flow |
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Flow Cardiac Output increase vs decrease |
Increase - Volume loading, Chronotropic agents, inotropic agents Decrease- inhalation anesthetics, hypovolemia, dysrhythmias, ischemia, high mean airway pressures |
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Systemic Resistance Increase vs Decrease |
Increase - Sympathetic simulation (pain), a-Adrenegric agonists Decrease - Various anesthetic agents, vasodilators, a-Adrenergic antagonists, B-adrenergic Agonists |
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Pulmonary resistance increase vs decrease **** |
Increase - hypoxemia, hypercarbia, acidosis, high mean airway pressure, sympathetic stimulation, a-Adrenergic agonists, Hypervolemia * Decrease- Oxygen, Hypocarbia, alkalosis, Prostagladin E1, a-Adrenegric antagonists, vasodilators, cGMP - Viagra * |
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Atrial Septal Defect |
Allows blood to shunt from atrium to atrium >8mm likely require intervention Ostium Secundum - Central and Most common |
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Atrial Septal Defect degree of shunting depends on what |
1. the compliance of the two chambers 2.The larger the defect , the greater the volume of shunted blood usually left to right shunt |
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Atrial Septal Defects |
Rarely close spontaneously, Paradoxical embolization at risk, can cause CHF with large shunts, and can cause pulmonary vascular resistance changes over time |
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Atrial Septal Defect Repair? |
Truly curable. can be closed with: surgery - patch or suture closure Cath lab- catheter device closure |
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Atrioventricular Canal Defects |
Partial AV canal - primum ASD and Cleft in MV Complete AV canal - failed fusion of endocardial cushions. Large amount of shunting - CHF NEEDS EARLY SURGICAL INTERVENTION |
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Ventricular Septal Defects |
L to R shunt. - CHF and Pulmonary HTN size of shunt and magnitude of the shunt. May close spontaneously by age 5 Rarely symptomatic and require closure. |
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Tetralogy Of Fallot |
Narrowing of the RV ifundibulum or Pulmonary Stenosis VSD Overriding Aorta RVH |
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TOF |
Wide spectrum right to left shunting at the VSD and thus systemic desaturation presenting as cyanosis* |
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Primary therapy to tx |
surgical - closure of VSD and relief of any RVOT obstruction |
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TOF Tet spells |
Hypercyanotic episode- due to increased right to left shunting from decreased systemic blood pressure and increased RVOT obstruction. |
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Treatment of TET spells |
increase intravascular volume 100% of FiO2 adequate ventilation Phenylephrine increase SVR Beta blockade (minimize spasms) Narcotics |
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Total Anomalous Pulmonary Venous Return |
Left to right shunt 0.6% percent see on autopsy Obstructed TAPVR requires emergent surgery. pulmonary HTN- occurs 50% patient preoperatively |
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Transposition of Great Arteries - mortality |
Without intervention, mortality is 45% in first month to 90% at one year. Patients with TGA rarely have other extra cardiac defects |
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Transposition of Great Arteries Patho |
In simple TGA- the aorta arises from the Right ventricle and the pulmonary artery arises from the left ventricle Incompatible with life unless other inter-circulatory mixing. systemic circulation unoxygenated, pulmonary circulation - oxygenated blood circulation |
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Early tx of TOGA |
PGE1 to keep PDA OPEN*** or need ASD or VSD balloon atrial septostomy sx- arterial switch operation/procedures |
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Truncus Arteriosus |
NEED VSD*** septation between the aorta and pulmonary artery that occurs 4-5 weeks after conception The basic defect is a large VSD and the pulmonary arteries arise directly from th aorta. |
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Truncus Arteriosus results in |
mixing of systemic and pulmonary blood b/c of the absence of a separation between circulations
in neonate the streaming and increased PVR direct blood flow to the systemic circulation |
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Truncus Arteriosus causes what systemic disease |
as the PVR decreases in the young infant, pulmonary over circulation rapidly occurs and CHF develops IRREVERSIBLE VASCULAR DISEASE- if left untreated*** mortality high if untreated |
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Tx of Truncus Arteriosus |
Early tx of CHF and alteration of pulmonary blood flow surgical correction is undertaken after stabilization and involves closure of the VSD and placement of an RV to PA conduit |
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Patent Ductus Arteriosus |
10% isolated finding usually with complex CHD in fetus right to left After birth left to right Typically closes over first 72 hours |
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PDA |
The risk of endocarditis generally mandates closure of the PDA. L to R shunt. Large PDAS steal from systemic circulation lowering diastolic B/P and putting coronary circulation at risk |
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PDA ligation closure options |
Surgical Ligation Trans-Catheter coil embolization or device. |
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Coarctation of the Aorta |
Untreated - cardiac failure, aortic rupture, endocarditis, CVA. Rigid-like thickening originating from the aortic media and protruding from the lateral and posterior walls of the aorta. - as the child grows the lumen is further comprised. |
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Coarctation of the Aorta Major Patho effect** |
Increased Afterload on the systemic ventricle. ** Results in LVH** Hypertension proximal to the coarctation and hypotension distal to the coarctation is common** Feeding hard |
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Coarctation of the Aorta ** |
Tx Surgical and Ballon dilatation HTN requiring antihypertensive therapy may persist in spite of early repair***** |
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Hypoplastic Left Heart Syndrome |
Aortic valve atresia with resultant hypoplasia of the ascending aorta. ** LV non functional ** NEED PDA OPEN. ** Transverse and ascending aorta are supplied retrograde through a PDA and the descending aorta ante grade from the PDA |
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Hypoplastic Left Heart Syndrome MUST HAVE |
PDA Atrial Mixing Q;Q close to 1 PBF and SBF are dependent on the ratio of PVR:SVR AS PVR decrease systemic perfusion deteriorates Compensatory increase in SVR worsens the problem** |
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Single Ventricle Physiology |
systemic venous blood mixes with oxygenated blood form the lungs. after birth PVR Drops and PBF increases relative to systemic flow. causing a rise in O2 sats and drop in systemic BP*** |
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Single Ventricle O2 estimate |
Useful to use O2 sats to estimate ratio of pulmonary to systemic blood flow balanced systemic artery sat is 75-85% Excessive PBF >85%- overcirculation and ventricular dilation, decrease systemic b/p Decreased PBF <75%- cyanosis, myocardial ischemia, and low cardiac output |
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Single Ventricle clinical presentation |
Cyanosis - avoid supplemental o2 with Large PDAs Resp distress within first 24-48 hours of life. ductus arteriosus begins to close or ASD restrictive. Lethargy, poor feeding, shock, seizures, renal failure |
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Hypoplastic Left Heart Syndrome |
PVR decrease PBF increase causing overload- systemic circulation poor . results in acidosis, chf and death despite increase arterial oxygenation |
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Tx hypo plastic left heart syndrome |
Early medical - stabilizes hemodynamic, decrease PaO2 and raise PaCO2 to raise PVR correct acidosis vasodilators to decrease SVR PGE1 to keep PDA open. |
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Hypoplastic left heart syndrome Norwood surgery |
Norwood stage 1- Aortic arch reconstruction by anastomosis of main PA to ascending and transverse aortic arch with patch aterioplasty systemic to PA shunt Atrial septectomy |
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Hypoplastic left heart syndrome norwood stage 2 at 4 months |
bidirectional glenn shunt stage 2 at 4 months removal of systemic to PA shunt anastomosis of SVC to PA decreased PVR 3-6 months will have normal filling |
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Stage 3 fontan |
at 2 years Redirect IVC blood to PA- near complete systemic venous return to the lungs for oxygenation RA and RV now almost fully oxygenated for systemic via neo-aorta |
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Long term implications with fontan |
arrhythmias aflutter or intra-atrial reentry tachycardia protein-losing enteropathy Thrombosis |
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Anesthetic implications of Adults with completed fontan |
CVP (pulmonary venous pressure)- dictates pulmonary blood flow. Avoid hypoxemia, hypercarbia, metabolic acidosis, increased catech, and myocardial depressants to prevent increase in pulmonary vascular resistance |
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Antibiotic prophylaxis who gets it |
Prosthetic cardiac valve, cardiac transplant, endocarditis CHD- unrepaired or incompletely repaired (Cyantoic blue heart Completely repaired in the last 6 months with prosthetic material. repaired CHD residual defects at the site or adjacent to prosthetic patch or device |
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Procedures that need antibiotic prophylaxis |
Dental procedures (with gums),
Respiratory Procedures (tonsils/adeno) incision or biopsy Infected tissue such as I/D of infected tissue |
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When to give antibiotic |
give 30-60 minutes prior to procedure if dose missed given within 2 hours after procedure. |
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Ventilation Hypercarbia vs Hypocarbia |
hypercarbia - increase PVR, decrease SVR, shunts Hypocarbia - decrease PVR and increase SV, shunts Positive pressure- CO, PEEP, and Lung vol. |
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Specifics of surgery |
Almost never B blockers or Ca Antagonists R-L delayed induction- air emboli L-R increased induction |
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good tricks |
maintain HR, Contractility and preload to maintain cardiac output. Always think - preload, rate, rhythm, contractility, and after load. |
