DKA Vignette II

Question 1

_______ derangements are also common and dangerous for patients with DKA

Answer 1

Potassium

Question 2

As the patient fights dehydration, the body compensates by holding onto _______ more avidly

Answer 2

sodium

Question 3

Increased _______ conservation in the distal convoluted tubule and cortical collecting duct of the nephron is mediated by aldosterone, which stimulates an antiport mechanism whereby _______ is retained at the expense of _______ loss in the urine. Therefore, patients in DKA are depleted in their total body _______

Answer 3

• sodium
• sodium
• potassium
• potassium

Question 4

Increased sodium conservation in the _______ and _______ is mediated by aldosterone, which stimulates an antiport mechanism whereby sodium is retained at the expense of potassium loss in the urine.

Answer 4

• distal convoluted tubule

- cortical collecting duct of the nephron

Question 5

Increased sodium conservation in the distal convoluted tubule and cortical collecting duct of the nephron is mediated by _______, which stimulates an antiport mechanism whereby sodium is retained at the expense of potassium loss in the urine.

Answer 5

-aldosterone

Question 6

Acidosis leads to influx of _______ ions into the cells, leading to a charge neutral efflux of _______. Therefore, the acidosis can cause an excess of _______ despite the overall depletion.

Answer 6

• hydrogen
• potassium
• extracellular potassium (hyperkalemia)

Question 7

a patient in DKA may present with _______ but will manifest _______ needs than most other patients you encounter

Answer 7

• hyperkalemia

- greater potassium

Question 8

as you treat this patient, you must continue to watch _______ levels and be prepared to make adjustments to the _______ content of IV fluids in order to prevent severe _______ and severe _______, both of which can lead to death.

Answer 8

• serum potassium
• potassium
• hyperkalemia
• hypokalemia

Question 9

_______ is the “lethal” part of the three drug lethal injection cocktail used by the majority of the 32 states with the death penalty.

Answer 9

potassium chloride

Question 10

_______, occurring in about 0.15-0.3% of all cases of pediatric DKA, is the leading cause of morbidity and mortality, with a death rate ~24%. A further 20% of patients with _______ suffer long term neurologic outcomes

Answer 10

Cerebral edema, Cerebral edema

Question 11

Acidosis leads to dysregulated _______ blood flow and perhaps even disruptions at the level of the blood brain barrier. Part of the process can be _______ as we rehydrate the patient with relatively _______ fluids.

Answer 11

• cerebral
• iatrogenic
• hypotonic

Question 12

we aim to replace fluid losses more slowly than you would in cases of non-diabetic dehydration, preventing _______ and slowing the rate of _______

Answer 12

• decreases in blood sodium concentration

- decrease of blood glucose

Question 13

Overly rapid rehydration and hypotonic IV fluids can precipitate _______, which manifests as: _______

Answer 13

• cerebral edema
• mental status changes; headache; Cushing’s triad (hypertension, bradycardia, irregular respirations); or fixed, dilated pupils.

Question 14

Treatment for cerebral edema includes

Answer 14

elevating the head of the bed, hyperventilating the patient (if intubated) [N.B. Rapid decrease in serum CO2 constricts cerebral arteries and therefore decreases cerebral blood flow], and giving IV mannitol or hypertonic saline.

Question 15

Given via IV, _______ serves to raise the effective osmolality of the blood and pull water back from the brain in order to decrease swelling.

Answer 15

Mannitol

Question 16

Be able to identify straightforward DKA

Answer 16

• Ill appearance, rapid breathing, nausea/vomiting/belly pain, dehydration
• Hyperglycemia, Ketones in blood/urine, acidosis (low pH and HCO3-)

Question 17

Describe the major metabolic disturbances in DK

Answer 17

• High blood sugar (>200 mg/dL)
• Acidosis (low pH and HCO3-)
• Potassium may be high or low (typically normal to elevated blood levels early on, but with risk of falling potassium during treatment)
• Dehydration

Question 18

Describe the stimulus for insulin release:

Answer 18

Glucose enters the beta cells in the pancreas –> increased ATP/ADP ratio –> closes a channel to cause rising intracellular potassium –> increasing intracellular potassium depolarizes the membrane –> Calcium ions influx –> leads to insulin exocytosis

Question 19

Describe at least three target-site actions of insulin

Answer 19

• Liver – store glucose (as glycogen) and lipid, stop lipid and glycogen breakdown
• Muscle – store glucose, make protein
• Adipose – store glucose and triglyceride (incorporated into chains of fats)

Question 20

Describe the risk for cerebral edema in DKA.

Answer 20

• Cerebral edema is the major cause of morbidity and mortality in DKA
• May be present even before treatment starts, but some treatment factors can cause/exacerbate it:
• –Rapid drops in glucose and sodium from too much or too hypotonic IV fluid
• Presents with mental status changes, headache, Cushing’s triad, fixed/dilated pupils.
• Treatment is to raise the osmolality of the blood.