Flashcards in Blood Gases & Hypothermia: Topic 3 Deck (107)
What do the major differences between adult and pediatric CPB stem from?
Myocytes/Myofibrils in Peds
Increase in size
Number of Mitochondria in Peds
Increases as the oxygen requirements of the heart rises
Amt of Sarcoplasmic Reticulum in Peds
Amount of Sarcoplasmic reticulum and its ability to sequester calcium increase in early development
Activity of Na+/K+ Adenosine Triphosphate (ATPase) in Peds
Increases with maturation and affects the sodium-calcium exchange
What happens when kids don't have adequate pulmonary blood flow?
Won't grow (also blue babies....)
What structure is response for SR storing calcium? (Affects ability to release too)
Ca++ handling in the immature myocardium _________(increases/decreases) intracellular Ca++ concentrations post ischemia/reperfusion.
What does an increase in intracellular calcium concentration activate?
Energy-consuming processes --> decreased levels of ATPase--> lack of energy sources for cardiac function--> dysfunction observed after CPB
What leads to cellular damage after CPB?
Abnormal and uncontrolled activation of these enzymes
What is the pediatric increase in myocardial oxygen demands attributed to?
Associated with a switch from anaerobic metabolism after birth to a more aerobic metabolism
Immature myocardium uses what substrates?
Medium and long chain fatty acids
What is considered the "mature" heart?
What are the primary substrates in the mature heart?
Long-chain fatty acids
What happens when the long-chain fatty acids become primary substrates in the mature heart?
Enzymes and an increased number of mitochondria are needed
Why can the immature heart withstand ischemic injury better than adult myocardium?
Because of the increased ability of the immature myocardium to rely on anaerobic glycolysis
What are premature infants prone to?
What can hypocalcemia result in?
Hypoxia, infection, stress, diabetes
What are the effects of hemodilution in neonates?
Decreased plasma proteins, coagulation factors and Hgb
Reduction increases organ edema, coagulopathy and transfusion requirements
Infants/neonates have a ______ (high/low) oxygen-consumption rate
What flow rates to infants/neonates require?
200 ml/kg/min at normal temperature (kg based flow rates)
What are unique anatomic and physiologic findings in patients with congenital cardiac disease?
Intra-cardiac and extra-cardiac shunts and the reactive pulmonary vasculature
How does glucose management on CPB differ between adults/pediatrics?
Adults: control high blood sugar
Peds: control low blood sugar
Why do peds get hypoglycemia?
Decrease in glycogen stores
Why do adults get hyperglycemia?
CPB --> stress response --> hyperglycemia
How does hematologic management differ between adults and pediatrics?
Adults: Inflammatory response
Pediatrics: exaggerated response; inflammatory response inversely proportional to age
What is the relationship between inflammatory response and age?
Inversely proportion; younger children have a higher inflammatory response
What are the events that trigger stress?
CPB causes hormone release and also releases what?