Chap 7 Ischemia Reperfusion Flashcards Preview

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Flashcards in Chap 7 Ischemia Reperfusion Deck (12):
1

What is the main cause of injury during ischemia?

From hypoxia/anoxia and stasis in microcirculation

2

Describe how ischemic injury occurs.

Mitochondria without O2 cannot produce ATP by oxidative phosphorylation
ATP falls, with ADP and AMP rise.
Glycolysis stimulated but insufficient for the cell
Lactic acid builds up making intracellular pH decrease, this then inhibits glycolysis
To compensate ion pumps are supposed to pump H ions out however there is pump dysfunction as no O2. Intracellular Ca rises are a consequence
This leads to eventually cell memebrane damage and cell death
During process reactive O2 species produced and accum in mitochondria
Increase ROS and Ca causes cell necrosis

3

What are the main causes of injury during reperfusion?

Metabolic, thrombotic, inflammatory

4

Describe reperfusion injury.

Burst of ROS production, increased Ca uptake into mito, shift of pH towards enutral
Mitochondrial oxidative damage leads to cell death through apoptosis and necrosis
Increased ROS during ischemia and reperfusion initiated apptosis and necrosis

Elicits inflamm response dependent of complement
Imflamm mediators delivered to reperfused tissue (mac, lumphocytes, neutrophils, mast cells and plt)
Edema

5

List clinical manifestations of reperfusion injury.

myocardial stunning
arrhthmia
tissue edema
multi-organ dysfunction
compartmenet syndrom
bacterial translocation
RF
ARDS
no reflow phenomena

6

Describe myocardial stunning.

Reversible, decreased ATP resunthesis, coronary spasm, cytotoxic injury

7

Describe arrhythmia.

Rapid and sudden changes in ions concentration

8

Describe tissue edema.

Disruption to blood brain barrier can cause increased ICP

9

Which organ most injured in multi-organ dysfunction.

Lungs most frequently injured

10

How long before nerve ischemia is permanent in CS.

12-24 hours

11

What causes bacterial translocation.

increased intestinal permeability.

12

What is no reflow phenomena?

Downstream microembolization of plt, neutrophils, thrombus, and atheroma particles cause occlusion. absence of obstruction in named arteries