Hormone Haywire
This RAAS hormone acts as an efferent arteriole vasoconstrictor at normal levels
What is angiotensin II (AT II)?
*Remember receptors exist on both afferent and efferent, there's just more on efferent
A patient who comes in with pneumonia and then presents with septic shock likely has high AG metabolic acidosis due to the presence of this acid
What is lactic acid?
*Bicarbonate levels lowered to compensate for H+, but lactate roams around without being measured (hence high AG)
Generally, metabolic acidosis is characterized by a decrease in this ion
What is bicarbonate (HCO3-)?
*Less base means more acidic and thus lower pH!
By upregulating ENaCs and Na-K ATPases, this hormone can increase ECF volume with more sodium and thus water retention
What is aldosterone?
*Will excrete hydrogen and potassium ions as part of its exchange!
A high anion gap metabolic acidosis implies high concentrations of organic acids without compensation by this ion that is NOT bicarbonate
What is chloride?
*Some compounds include ethylene glycol, ketones (DKA), and salicylates
What is hyperventilate?
*You lower pCO2 to minimize how much "acid" can dissolve, which increases pH
If severe enough, a drop in the total amount of this ion can trigger the release of ADH when normally it's triggered by lowered concentration
What is sodium?
*This is primarily due to greater than 10% effective volume depletion. Aldosterone attempts to bring sodium but will also use ADH to achieve this effect
With rapid lipolysis from no insulin, compounds like beta-hydroxybutyrate and acetoacetate trigger this cause of high AG metabolic acidosis
What is diabetic ketoacidosis (DKA)?
*Ketone bodies split into hydrogen and its anion, the latter which replaces bicarbonate!
One of the most common ways to lose bicarbonate for this acidosis is through this GI symptom
What is diarrhea?
*Lose stools drop bicarbonate levels, but the kidney will reabsorb chloride to maintain negativity
By binding onto this specific receptor, ADH can open aquaporin-2 channels to increase ECF with more water
What is V2 receptor?
*Binding to V1 on blood vessels will constrict smooth muscle and increase blood pressure!
Related to high anion gap metabolic acidosis, a patient could ingest a toxic substance to increase this gap in the serum
What is osmolar gap?
*ME DIE involves a lot of compounds with alcohol functional groups
A failure to reabsorb bicarbonate in the earlier parts of the kidney represents this renal tubular acidosis
What is proximal/type II renal tubular acidosis?
*All the RTAs trigger a normal anion gap!
A dilation in this heart region will release ANP, which can promote salt and water excretion and downregulate other renal hormones
What is (right) atrium?
*It will dilate afferent arterioles and increase filtration while limiting the effects of renin, ADH, and aldosterone!
Failure to excrete non-volatile acidic anions (like phosphoric acid) and having nitrogenous wastes like BUN and creatinine implies this cause of high AG metabolic acidosis
What is uremia?
*Cannot make the NH3 buffer for H+ excretion!
This fluid, when given intravenously, can actually lower bicarbonate levels and trigger a normal anion gap metabolic acidosis!
What is normal saline?
*This is mostly done via dilutional methods, but it can also be due to excess chloride (and anions) forcing a decrease in bicarbonate to compensate