Diabetic Ketoacidosis

Question 1

Name at least 5 important signs and symptoms of diabetes

Answer 1

Rapid deep breathing (elevated heart rate)
Fruity odor to breath
diffuse TTP on abdomen
Cool hands and fee, cap refill of +4sec
Polyuria/ noctiuria
\+N/V
elevated BS
Glucose in urine
unintentional weight loss

Question 2

What pancreas cells release insulin

Answer 2

Beta cells
Type 1 DM is autoimmune process that destroys these cells
51 amino acid protein
4-6 minute half life

Question 3

Describe the path/ effect of glucose on cells

Answer 3

Glucose enters @ GLUT2 transporter -> glycolysis -> increase [ATP] v [ADP] -> ATP sensitive K+ channel closes -> intracellular increase in K+ -> membrane depolarization -> voltage gated Ca channel activated -> Ca influx -> exocytosis of insulin containing secretory granules

Question 4

Describe the basic function of insulin

Answer 4

“locks up” energy

• Glucose and triglyceride uptake
• Synthsis of fats, proteins and glycogen (inhibiting their breakdown)

Question 5

Name 3 tissues where insulin acts

Answer 5

Liver
muscle
adipose

Question 6

What is insulin’ action on the liver

Answer 6

\+ glucose uptake
\+ glycogen synthesis
- ketigenesis
- gluconeogenesis
\+lipogenesis

Question 7

What is insulin’s action on muscle?

Answer 7

+ glucose uptake
+ glycogen synthesis
+ protein synthesis

Question 8

What is insulin’s action on adipose?

Answer 8

+ glucose uptake
+ triglyceride uptake
+ lipid synthesis

Question 9

What is the cause of and treatment for elevated blood sugar in diabetic ketoacidosis?

Answer 9

cause: insulin usually signals uptake of sugar, w/ destruction of B cells, no longer happens -> extracellular glucose builds up

Tx:

1) IV insulin (decrease BS, halting ketoacid production)
- Because it takes longer to resolve ketoacidosis:
2) IV dextrose hrs before stopping insulin

2 cardinal signs in DKA management: prematurely stopping insulin
or failing to use enough dextrose

Question 10

What causes acidosis in DKA patients? What is its effect?

Answer 10

Cause: result of beta oxidation of fatty acids -> produces H+ ions and ketone bodies

Result/ compensation: Increase in respiratory volume (hasten elimination of CO2)

Question 11

What is the equilibrium equation for carbon dioxide and bicarbonate?

Answer 11

H+ + HCO3- H2CO3 H2O + CO2

Question 12

What causes the dehydration seen in DKA patients?

Answer 12

osmotic diuresis 2/2 hyperglycemia:

• usually blood filtered in kidney and glucose reabsorbed
  _ in DKA glucose is too high to be reabsorbed -> glucose lost in urine
• Elevated concentration of urine -> increased osmolarity-> decrease in water reabsorption

Ultimately leads to nausea and vomiting

as blood concentration of glucose increases, sipral worsens

=> best Tx = iv fluids

Question 13

Explain the potassium derangement seen in DKA patients

Answer 13

patients fight dehydration by holding Na more tightly -> in kidney Na retained at expense of K

K lost in urine

tricky because this can cause overall hyperkalemia (outside cells) despite shortage

Question 14

Explain cerebral edema in DKA

Answer 14

incompletely understood

Due to acidosis -> disregulated cerebral blood flow (disruption of BBB?)
= Iatrogenic: must rehydrate slowly => Cerebral edema

Question 15

What are they symptoms of cerebral edema?

Answer 15

mental status change
cushing’s triad (HTN, Bradycardia, irregular respirations)
Fixed, dilated pupils

Question 16

What is the treatment for cerebral edema?

Answer 16

mannitol -> minimally metabolized -> stays in blood -> increases effective osmolality of blood -> pull water back from brain (BBB) and decrease swelling