Memory Master Test 2

Question 1

What hemodynamic alteration may worsen (increase flow through) a left-to-right intracardiac shunt?

Answer 1

Increase in SVR such as ASD

Question 2

What is patent ductus arteriosus? When does the ductus arteriosus normally close?

Answer 2

Patent ductus arteriosus is an abnormal persistence in the newborn of blood flow through the ductus arteriosus.
Normally the ductus closes within a few hours to a few days after birth due to changes in pressures of the pulmonary vasculature

Question 3

Name the physiologic factor most responsible for closure of the ductus arteriosus after birth.

Answer 3

Normal closure occurs in response to increased arterial oxygen tension PaO2 as well as reduction in circulating prostaglandins.

Question 4

Is patent ductus arteriosus a right to left or a left to right?

Answer 4

Left to Right

Question 5

With patent ductus arteriosus what cardiovascular changes occur?

Answer 5

a PDA allows blood to flow from aorta into pulmonary artery.
Additional blood is reoxygenated in the lungs and returned to the LA and LV and this causes increased workload on the left side of the heart and LV hypertrophy and increased pulmonary vascular congestion and resistance
Most patients are asymptomatic

Question 6

What is the probable problem if the pediatric patient has a systolic and diastolic murmur?

Answer 6

Patent ductus arteriosus

A continuous systolic and diastolic murmur is often the only manifestation of PDA

Question 7

Where are pulse oximeters placed on the neonate to monitor preductal and postductal oxygenation?

Answer 7

Preductal - Right hand or finger

Postductal - Left foot or left toe

Question 8

What is the purpose of the preductal oximeter in the neonatal patient undergoing cardiac surgery?

Answer 8

Measurements of arterial oxygen saturation taken at a preductal location are a better index of neonatal cerebral oxygenation than are those taken at a postductal location. R to L shunt at the ductus arteriosus persists some time after birth PREDUCTAL PLACEMENT of the pulse oximeter is preferred
A POSTDUCTAL pulse oximeter can be used to quantify the degree of R to L shunt

Question 9

Where should arterial blood pressure be measured in patient undergoing repair of PDA?

Answer 9

Peripheral artery such as femoral (POSTDUCTAL)

Question 10

Does blood shunt R to L or L to R through the VSD in Tetrology of Fallot (cyanotic heart disease)?

Answer 10

Blood shunts R to L permitting unoxygenated blood to mix with oxygenated blood, resulting in cyanosis.

Question 11

What pharmacologic agent decreases a R to L shunt?

Answer 11

Phenylephrine increases SVR and decreases R to L shunt.

Question 12

The pediatric patient is scheduled for a radiofrequency ablation of an aberrant conduction pathway (eg WPW). What is a general anesthetic typically required for this scenario?

Answer 12

Anesthetic agents and technique should be chosen to maintain circulating catecholamines and avoid suppression of arrhythmogenesis.

Question 13

Four defects of Tetrology of Fallot

Answer 13

VSD
Right Ventricular Outflow Tract obstruction
RV Hypertrophy
Overriding Aorta- dextroposition of the aorta with overriding of the VSD

Question 14

Goals of anesthetic management for the patient who has TOF

Answer 14

Avoid PVR increases.

Maintain intravascular volume and SVR.

Question 15

An infant has TOF. Which of the following arterial blood gas parameters will not typically be changed PaCO2? pH? PaO2?

Answer 15

pH and PaCO2 are likely to be in the normal range

PaO2 is usually markedly decreased <50mmHg

Question 16

During the case, oxygen saturation decreases, apparently because of the increased shunting. The patient has TOF. What agents might be selected to decrease shunt and increase oxygen saturation?

Answer 16

IV fluid admin because acute hypovolemia increase the magnitude of R to L intracardiac shunt.

Alpha-agonist drug phenylephrine must be available to treat an undesired decrease in systemic blood pressure caused by a decrease in SVR.

Question 17

List 3 conditions that increase R to L shunt TOF.

Answer 17

Acidosis
Hypercarbia
Hypotension

Question 18

To what do preductal or postductal coarctation of the aorta refer?

Answer 18

Coarctation of the aorta refers to a discrete narrowing of aorta immediately distal to the origin of the left subclavian artery.

Preductal occurs proximal to the opening of ductus arteriosus

Postductal present in adulthood long after closure of the ductus arteriosus

Question 19

Should upper extremity blood pressure be monitored in the neonate with preductal coarctation of the aorta on the right or left arm?

Answer 19

PREDUCTAL = RIGHT RADIAL ARTERY

Question 20

Best site to get ABG from neonate?

Answer 20

Right radial artery

Site will also preductal oxygen saturation which better reflects cerebral oxygenation

Question 21

What is the anesthetic concern for a patient undergoing repair of VSD with pulmonary HTN?

Answer 21

Patient often is already R to L shunting through VSD. If VSD closed before 1 year often normal ventricular function and ejection fraction.

Changes may increase PVR can cause rapid deterioration including hypoxia, hypercarbia, acidosis, hypothermia, atelectasis, sympathetic stimulation, and polycythemia.

Question 22

R to L intracardiac shunt is present in a patient with VSD with Eisenmenger’s syndrome. What hemodynamic alterations may worsen (increase shunt flow) the R to L shunt of VSD with Eisenmenger’s syndrome?

Answer 22

An abrupt increase in PVR or decrease in SVR is poorly tolerated in VSD patients.

Avoid interventions that may increase PVR or decrease SVR in the patient with R to L intracardiac shunt.

Question 23

Will a R to L shunt theoretically slow or accelerate inhalation induction? Is this clinically significant?

Answer 23

Slow inhalation inductions but is rarely problematic.

Question 24

R to L shunt will slow or accelerate intravenous induction?

Answer 24

Accelerate

Question 25

L to R will slow or accelerate inhalation induction

Answer 25

Accelerate

Question 26

L to R will slow or accelerate intravenous induction

Answer 26

Slow