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Clin Med - Electrolyte Correction & Acid-Base

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drraythe's version from 2016-03-14 19:54

Electrolyte Corrections

Question Answer
What is the amount of sodium which would be considered HYPOnatremia? What happens to the ICF? What are some reasons for why this would happen?<120meQ/L. ICF SWELLS! This could be due to an ↑ in free water, or from diarrhea, or Renal Dz
Explain how you need to treat acute vs chronic hyponatremia differentlyIn acute hyponatremia, you lost the salt fast so you can replace it fast! In a chronic case, however, you lost it slow so you must replace it slow!! (bc there has been cell adaptation)
***What happens if you had a chronic hyponatremia & then you treated quickly?You can cz OSMOTIC DEMYELINATION!
What are the CS like in ACUTE hyponatremia? CHRONIC? (General not specific)ACUTE: RAPID cellular swelling, you will see neurologic CS
CHRONIC: cells adapt, there may or may not be CS
What is the amount of sodium which would be considered HYPERnatremia? What happens to the ICF? What are some reasons why this might happen?>160mEq/L. ICF SHRINKS! This could be due to dehydration, or inappropriate intake
If you have hypernatremia, what forms over time? If the hypernatremia formed slowly as a chronic process, how must you treat it & what is the danger if you treat improperly?Over time, "idiogenic osmoles" will form (internet says: brain shrinkage is minimized by the accumulation of additional solutes w/in brain cells. These are the "idiogenic osmoles"). If the process was chronic (slow to form), then you must TREAT slowly, or you risk cerebral edema
What is the m/Eq/L she gave us for K+? (Internet said it was the intracellular level) what are the 2 systems you'd see the most CS in if there was a problem w/ K+?150mEq/L!! You will see neuromuscular & cardiovascular CS
What are the CS you'd see in HYPOkalemia?Muscle weakness, skeletal & GI weakness → ileus (disruption of the normal propulsive ability of the gastrointestinal tract).
What are some reasons you'd get HYPOkalemia?Anorexia (ESP IN HORSES), prolonged IV fluids & diuretics
****WHAT IS THE MAXIMUM POTASSIUM SUPPLEMENTATION RATE???DO NOT EXCEED 0.5mEq/L/HOUR
There is a chart on slide 9 w/ serum potassium & potassium supplementation sizesI have no idea if we need to know this
Think Dr. C said in class: Who are you most prone to see ↑ levels of K which kill them?Blocked cats (can't excrete the K+)
What are the main CS you'd see w/ HYPERkalemia?Bradycardia & arrhythmias
What are the 4 main reasons you'd see a HYPERkalemia?(1) Metabolic acidosis (push H+ in means K+ has to go out into serum)
(2) HyPP
(3) Post-Renal Dz (blocked or ruptured bladder, ureter/urethral obstruction, patent urachus in foals)
(4) Iatrogenic (this is usually fatal)
What does HYPERkalemia look like on a ECG? What is the resulting effect on the heart?(See slide 11 for pic of ECG waves) NO P-waves, TALL peaked T-waves, a PROLONGED QRS complex. This can lead to bradycardia & CAN progress to sinus arrest
How would you go about treating HYPERkalemia?Fluid diuresis w/ 0.9% NaCl, dextrose, +/-bicarb, +/-Ca++
What does↓K+ do to the action potential generation? (Is it affecting resting potential or threshold potential)?Resting potential: ↓ it, so needs to travel longer distance to threshold
What does ↑ K+ do to the action potential generation? (Is it affecting resting potential or threshold potential)?Resting potential: ↑ it, so needs to travel shorter distance to threshold
What does ↑ Ca++ do to the action potential generation? (Is it affecting resting potential or threshold potential)?Threshold potential: ↑ it, so needs to travel longer distance to depol
How does↓Ca++ do to the action potential generation? (Is it affecting resting potential or threshold potential)?Threshold potential: ↓ it, so needs to travel shorter distance to depol
Explain the hypercalcemia vs hypocalcemia effect on the heartNormally I think Ca++ czs a contraction, so ↑ Ca++ would lead to MORE heart stuff, right? Nope. ↑ Ca++ means you are LESS likely to depolarize. All muscles contract bc of INTRAcellular Ca.... & we are talking about EXTRAcellular Ca++. There's why it's so confusing. You're welcome.
What level of bicarb would you start to think about supplementing?If it's less than 15mEq/L
Bicarb → severe acidosis is when the pH is <_________.<7.2
What should you NOT mix bicarb w/ when administering?Ca++
What is the little equation to determine how much bicarb to give? & HOW should you give it?Bicarb = (0.3) (BWKg) (Base Deficit). You'd start by giving a quarter to a half of the dose slowly by IV for 6 hours, reassess & if needed give the rest over a period of 24hrs
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Acid-Base Intro

Question Answer
Why do you do a blood gas evaluation? What are the 2 types of samples you can take to do a blood gas evaluation? What kinda syringe should you use?You are looking at the GAS EXCHANGE occurring in the vessels. You can check the arterial VS the venous blood gas. For this you will want a heparinized syringe w/ NO air bubbles
What are the sites for ARTERIAL blood gas in SMALL animals?Pedal Artery
Femoral Artery
What are the sites for ARTERIAL blood gas in LARGE animals/eq?Facial artery
Transverse Facial Artery
Great Metatarsal Artery
How can you use blood gas evaluation to determine if the PTx is hypoxemicPaO2 will be <80mmHg in ARTERIAL BLOOD GAS ONLY (venous is already deoxygenated)
How might you use blood gas to determine if the dz is respiratory or systemic?You can compare the arterial & venous blood gasses!
What things would you want to measure in the blood to determine if an acid-base disturbance was present? (3)pH, HCO3-, PCO2 (acidemia? alkalemia?)
FYI for picky people: Diff btwn acidemic & acidotic?Demic in blood, dotic is in the overall body/pt
What are the 2 1° things you'd look at in an acid-base disturbance?HCO3- & PCO2
What would you look at to determine if the acid-base disturbance was simple or mixed?The PATTERN of HCO3-& PCO2
You can look at these factors to determine if there is systemic compensationHCO3-& PCO2
****What is the normal pH value for dogs & cats???7.4
Acidemia can be czd by too much ___ or too little ___Too much PCO2, not enough HCO3-(too much acid or too little base)
Acidemia can be cz by ___ventilationHypo
In a 1° acid-base disorder, HCO3-& PCO2 should move how, relative to each other?Should move in the SAME direction
When a 1° acid-base disturbance alters 1 component of the ratio, the other component offersCompensation
****Amazingly helpful way to remember how to figure out if it is respiratory or metabolic acid base imbalance?R.O.M.E.
Resp = Opposite (pH & PCO2 going in opposite directions, ↑ or ↓)
Metabolic = Equal (pH & PCO2 moving in same direction, ↑ or ↓)
What are some reasons you could have a respiratory acidosis?CNS depression, CPA (cardiopulmonary arrest, I think), opiates, pleural dz, COPD/ARDS (chronic obstructive pulmonary dz/acute resp distress syndrome), musculoskeletal disorders, compensation for metabolic acidosis
What would be some reasons for a respiratory alkalosis?Hypoxemia (eg pulmonary or cardiac dz), CNS dz or hemorrhage, Salicylate intoxication, sepsis, iatrogenic tachypnea
What are the ways you might get a metabolic acidosis?(1) Gain of acid: Lactic acid, ketotic, toxin ingestion, ↓ renal excretion of H+
(2) Loss of base: GI loss-acute, V/D, failure of renal absorption
What is the equation for the anion gap? What is the normal value for this?(positives minus negatives, so:) [Na + K]-[Cl + HCO3]. The normal value will be about 16, +/- 4
What might be some czs of an elevated anion gap?Gain of acid, ↑ in endogenous acids (uremia, tissue hypoxia, diabetic ketoacidosis) Ethylene glycol (EG) intoxication.
What might be some problems which could still have a normal anion gap?Loss of base
Hyperchloremic
Renal Tubular Acidosis
Severe Diarrhea
**What would be some czs of a metabolic alkalosis?Loss of chloride in excess of ECF, ↑ GI obstruction, diuretics... for HORSES, also chronic diarrhea & massive sweat loss
In mixed acid-base disturbances, what is going on w/ the PCO2 & the HCO3-? What must you do?The PCO2 & HCO3-will move in DIFFERENT directions & you should fully evaluate PTx to identify both systemic responses!
**If a dog vomits... will it be in metabolic alkalosis or acidosis?METABOLIC ACIDOSIS! This is bc vomit comes from the small intestine, not the stomach & so you are going to lose the bile which is a base, so you will be proportionately more acidic
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