Eggena 18-1 Flashcards
the patient’s current problem is not related heroin because
a narcotic overdose depresses breathing and causes constriction of pupils, signs not seen on physical examination.
When a person with insulin dependent diabetes stops taking his usual dose of insulin or becomes resistant to insulin from an infection
glucose cannot enter muscle cells as usual so that glucose in blood rises well above its normal concentration.
Without insulin fatty acids are released from adipose tissues and converted to
ketones in the liver
the first line of defense against hydrogen ion insult is
buffering by bicarbonate in plasma.
kussmaul breathing
PaCO2 has fallen by half, indicating that laveolar ventilation is twice what is needed to get rid of the carbon dioxide his tissues are making. It is a deep, labored inspiration with a grunting expiration.
Shortly after hyperventilation started, the
PaCO2 in arterial blood fell, resulting in a decline in CO2 in CSF, decreasing CSF pH. This alkalosis inhibits central chemoreceptors, which masks the peripheral drive from chemoreceptors to hyperventilate.
renal bicarbonate reabsorption during meatbolic acidosis
bicarbonate reabsorption is increased due to activation sodium/hydrogen ion antiporters by the low intracellular pH and stimulationby angiotensin II.
to correct the bicarbonate defect
more ammonium and titratable acids must be excreted in urine.
normally, _ is the most titratable acid in urine
phosphate buffer
potassium sparing effect
Early in acidosis, when ammonium concentrations are low, much potassium is lost in urine. Later on, a greater proportionof the ketone load is excreted witha mmonium, so that the time dependent increase in synthesis and excretion of ammonium is said to have a potassium spaing effect.
why did the patient have an elevated serum potassium level if more potassium than usual is being excreted in urine?
hydrogen ions are moveing into muscle cells in exchange for potassium ions.
without insulin, Na/K ATPases are not transorting potassium ions into cells as usual.
the rise plasma osmolarity causes cells to shrink, intracellular potassium to rise, and potassium ions leak out.