Eggena 24-1 Flashcards
the immediate threat to the patient was not the ketoacidosis, but the dangerously high level of
plasma potassium (hyperkalemia)
To prevent ventricular fibrillation, the patient was given an intravenous injection of
calcium gluconate. It raises the threshold of cardiac muscle and protects the heart form the depolarizing action of hyperkalemia.
emergency measures for reducing plasma potassium are aimed at
shifting potassium ions into cells, primarily muscle and liver cells. This can be accomplished with insulin or beta-2-adrenergic agonists that stiumlate sodium-potassium or with sodium bicarbonate that draws hydrogen ions into out of cells on hydreogen/sodium ion antiporters.
sodium bicarbonate should be avoided in this situation because
it may cause matabolic alkalosis that could cause seizures and cardiac arrhythmias.
the patient was severely dehydrated and volume depleted, which had
decreased cardiac output and renal perfusion, causing an increase in BUN and creatinine and in their ratio.
type 2 diabetes is caused by
increased resistance of target cells (muscle and adipose cells) to insulin. The increase in resistance to insulin may be caused by a decrease in the number of functional insulin recceptors at the cell surface.
the pancreas does secrete insulin in patients with type II diabetes, but the amount of insulin secreted is
insufficient to overcome the desensitized target cells.
These patients have a relative deficiency of insulin, even though actually measured concentrations may be normal or even high.
_ is the most important factor that contributes to hyperglycemia.
obesity
counterregulatory hormones, such as excessive _ or excessive _ can induce a diabetes like condition with high plasma glucose by opposing the action of insulin.
growth hormone, cortisol
excess secretion of other hormones, _ and _, may sometimes be responsible for raising plasma glucose by inhibiting insulin secretion or interfering with its actions.
glucagon, somatostatin
stress from surgery or infections often raises
plasma glucose in diapetic patients; glucose returns to normal when the stress subsites.
Drugs such as corticosteroid preparations or diuretics, may
aggravate diabetes and cause hyperglycemia.
classical symptoms of diabetes are
polyuria
polydipsia
polyphagia
polyuria is caused by
loss of glucose in urine.
polyphagia results when cells in the
hypothalamic satiety center sense (incorrectly) plasma glucose to be too low.
The reason for this inappropriate hunger drive is that insulin is required for glucose entry into cells of the satiety center.