DKA Vignette I Flashcards
DKA is defined as
hyperglycemia, metabolic acidosis, and ketonemia/ketonuria.
D (diabetes, which is defined as abnormally high blood sugar),
K (ketones in the blood and urine),
A (acidosis).
metabolic threats to this patient include
hyperglycemia, metabolic acidosis, hyperkalemia (which can potentially devolve into hypokalemia if you are not careful in your management), and dehydration
Insulin is
a 51 amino acid protein released by the beta cells of the pancreas
In type 1 diabetes mellitus,
an incompletely understood autoimmune process leads to destruction of these beta cells and results in insulin deficiency.
Insulin release is regulated by a _______ within the _______
glucose sensing system
beta cells
glucose enters the cell through the _______, undergoes _______, leading to an increase in the intracellular _______ to _______ ratio.
GLUT2 transporter
glycolysis
ATP
ADP
The increase in the intracellular ATP and ADP ratio closes the _______, preventing _______
ATP-sensitive potassium channel
outward leak of potassium ions
The resultant buildup of intracellular potassium (because there are other sodium/potassium channels actively antiporting against the gradient) _______ the membrane, activating a _______ and leading to _______
depolarizes
voltage-gated calcium channel
calcium influx
The increased intracellular calcium ion concentration leads to
exocytosis of preformed insulin-containing secretory granules
Once released from the beta cell into the bloodstream, human insulin has a half-life of about _______, allowing for _______
5 minutes
minute-by-minute fine control of blood sugar
Insulin stimulates uptake of _______ and _______ while promoting synthesis of _______, _______, and _______
glucose triglycerides fats proteins glycogen
Insulin actions: Liver
+ glucose uptake, glycogen synthesis
- gluconeogenesis
- ketogenesis
+ lipogenesis
Insulin actions: Muscle
+glucose uptake, glycogen synthesis
+protein synthesis
Insulin actions: Adipose
+glucose uptake
+triglyceride uptake
+lipid synthesis
The intravenous insulin serves two purposes:
decreasing the blood glucose concentration and halting ketoacid production
Two cardinal sins in DKA management are
prematurely stopping the insulin infusion and failing to use enough dextrose to bring the blood glucose slowly into the target range.
The acidosis seen in DKA is a result of
beta oxidation of fatty acids
the beta oxidation of fatty acids generates
hydrogen ions and ketone bodies (acetoacetate and betahydroxybutyrate)
To compensate for the excess acid, the body increases _______e and rate to _______
- respiratory volume and rate
- hasten the elimination of carbon dioxide
_______ is very membrane permeable and readily removed from the body at a rate dependent on the volume of air ventilated per unit of time (usually discussed as
“minute ventilation,” and dependent on respiratory rate and the volume of air exhaled with each breath).
CO2
CO2 is very membrane permeable and readily removed from the body at a rate dependent on the _______ and dependent on _______
volume of air ventilated per unit of time (usually discussed as
“minute ventilation,” and dependent on respiratory rate and the volume of air exhaled with each breath)
The deep and rapid respirations seen in DKA are “_______.”
Kussmaul respirations
Easy to remember: K for Kussmaul, K for ketoacidosis
The dehydration seen in DKA is largely the result of
the osmotic diuresis secondary to hyperglycemia
In the normal state, blood is filtered at the _______, and as the filtrate courses through the _______, the _______ reabsorbs all the glucose filtered.
glomerulus
nephron
parsimonious kidney
in diabetes the blood glucose (and therefore filtrate glucose) concentration _______(all the transporter proteins are working at capacity), and glucose is _______.
- rises above levels which can be reabsorbed through facilitated diffusion
- lost in the urine
With an excess of _______ (and therefore osmols) in the filtrate, the body is unable to _______. Therefore, _______
- glucose
- reabsorb as much water as it would under normal conditions
- large volumes of water are lost in the urine, even in the setting of dehydration
as the blood ketoacid concentration rises, the patient experiences _______ and _______, making it even more difficult for oral intake to keep up with urine volume loss, resulting in _______
- nausea
- vomiting
- dehydration
dehydration leads to an _______, worsening the pace of the _______, a spiral that can often only be reversed with _______
- even further concentration of blood glucose,
- osmotic diuresis
- IV hydration
