Part 3: Pediatric anesthesia: Overview Flashcards
1
Q
Describe patent ductus arteriosis?
A
- Abnormal connection from the high pressure aorta to the low pressure pulmonary artery allows an increased volume load to the lungs and left heart.
- Arrow shows blood flow
2
Q
Describe atrial septal defect?
A
- Large volume load to right atrium from blood flow from left atrium
- Left to right shunt
- Right to left shunt occurs at atrial level
- Cases require CPB and anesthesia complexity is proportional to surgical complexity
- Air must be carefully avoided in all patients but especially in ostium primum patients
3
Q
Describe Ventricular Septal Defect?
A
- The most common congenital heart defect
- Left to right shunt
- Eisenmenger’s Complex – situation where pulmonary vascular disease results in pulmonary hypertension sufficient to reverse the shunt to right to left and cyanosis develops
- Air is of concern in all patients but especially as the flow equalizes or reverses
4
Q
Describe coarctation of the Aorta?
A
- This can occur before the ductus (preductal) at the ductus or after the ductus (post ductal). Each has different implications and hemodynamics
- Left ventricle supplies the upper body
- Right ventricle, through the ductus primarily supplies the lower body
- Significant difference in upper and lower body blood pressure
- 50% have bicuspid aortic valve
- May present early with CHF
- Preductal are often associated with other congenital problems and are more difficult to repair
- Postductal are commonly seen in older children
5
Q
Describe tetrology of fallot?
A
- Right to left shunt
- Decreased flow to lungs
- Increased flow to body
- Clubbing of extremities, iron deficiency anemia, polycythemia, transient cerebral ischemia
- Inhalation induction slow; less PA flow
- IV induction faster; R->L shunt to brain
- Hypoxia, hypotension, decreased CO, vasodilation (increased R->L shunt all put patient at risk)
- Squatting common, probably increases systemic resistance and lessens R->L shunt and increases pulmonary flow and oxygenation
6
Q
Describe endocardial cushion defect?
A
- Failure to develop results in mitral/tricuspid problems
- Flow can be in any direction between the four chambers
- Most common problem with Down’s syndrome
- Repair is long involving patches to form four chambers and reconstruct at least the mitral valve
- Often have problems with conduction system postop
- Almost always have pulmonary hypertension
7
Q
Describe Truncus arteriosis.
A
- Truncus divides into pulmonary artery and aorta
- Failure to form properly leaves a common trunk with venous and arterial blood
- Pulmonary blood flow varies with type – from increased to diminished
- In the fourth type, with no pulmonary artery, flow to lungs is via bronchial circulation
- Always cyanotic
- Often are in CHF at time of surgery
8
Q
Describe transposition of the great vessels?
A
- Ao attaches to the RV and PA attaches to the LV
- To be compatable with life other lesions must exist; PDA, VSD, or VSD
- Intact ventricular septum – Foramen ovale and ductus arteriosus allow mixing
- Degree of mixing determines “pink or blue” baby. Minimal murmur
- VSD – with decrease in pulmonary resistence R>L shunt occurs mixing via FO allows oxygenation. Holosystolic murmur and increased pul volume
- VSD with subpulmonic stenosis – here less pulmonary flow from the stenosis causes L>R shunt at VSD and R>L shunt at FO. As pulmonary flow decreases shunts increase and cyanosis worsens
9
Q
Describe Ebstein’s anomaly?
A
- Part of the ventricle is above the tricuspid valve
* R>L shunt
10
Q
Describe aortic stenosis & Left outflow obstructions?
A
- Three leaflet valve usually no regurg
* Two leaflet valve usually has regurg
11
Q
Describe pulmonary stenosis & right outflow obstruction?
A
Often associated with rubella syndrome
12
Q
Describe tricuspid atresia?
A
Blood flow is across atrial septum (FO/ASD)
