Fluids, Electrolytes, Nutrition Flashcards

Question

Working up hyponatremia

Answer 1

True hyponatremia = excess ingestion of water that overwhelms the kidneys (either normal or diseased) or due to increased ADH. It is NOT due to increased excretion of Na. 1) Determine plasma osmolality - Normal: pseudohyponatremia. Lab artifact due to high lipids or plasma proteins. Check a lipid profile or possible Multiple Myeloma - High - pseudohyponatremia. Due to increase of osmotically active molecules like glucose*** or mannitol - Low - true hyponatremia 2) Assess volume status - hypovolemia - euvolemia - hypervolemia

Answer 2

For every 100 mg/dl increment in plasma glucose above normal (normal = 100), plasma Na should decrease by 1.6 mEq/L "sweet 16" Glucose of 500 should have decrease of 6.4. 140-6.4 = 133.6

Answer 3

- Renal cause = diuretics - Extrarenal = vomit, diarrhea, burns, pancreatitis Differentiate using urine Na. Urine Na 20 indicated renal cause.

Answer 4

SIADH = #1 Increased vasopressin release from posterior pit or ectopic source causes decreased renal free water excretion Signs: - hypo-osmotic hyponatremia (hypotonicity) - Inappropriately concentrated urine (urine osmolality > 100) - Normal renal, adrenal, thyroid function Causes: - neuropsych disorders, malignancies (esp lung), and head trauma - glucocorticoid deficiency (Addison's) - cortisol deficiency causes hypersecretion of ADH - hypothyroidism - causes decreased CO and GFR which leads to increased ADH release - primary polydipsia - usually in psych patients who compulsively drink massive volumes of water

Answer 5

May be from CHF, cirrhosis, nephrotic syndrome Increased thirst and ADH Edematous state

Answer 6

Decreased reflexes, respiratory depression, seizures, coma N/v, HA, lethargy, muscle cramps For hypovolemic: Give 0.9% NaCl. Na repletion with saline isotonic to patient in order to avoid rapid changes in ICF volume. Major complication from rapid correction of chronic hyponatremia is central pontine myelinolysis For hypervolemic: Correct underlying disorder - CHF, liver or renal failure For euvolemic: Raise plasma Na (lower ICF volume) - restrict water intake

Answer 7

ALWAYS with hyperosmolarity Causes: - Loss of water (dehydration!): DI, diuretics, sweating, GI loss, burns, fistulas - Gain of Na due to excess mineralocorticoid activity: Primary hyperaldosteronism, Cushing's, renal artery stenosis (hyperreninism), congenital adrenal hyperplasia (will also cause hypoK) - If thirst mechanism is intact and water is available, hypernatremia will not persist. Suspect hypernatremia in young, elderly, and patients with AMS who may not have access to water Symptoms - thirst - restlessness, weakness, delirium - hypotension and tachycardia - decreased saliva and tears - red, swollen tongue - Oliguria Tx - Calculate free water deficit - If euvolemic - replace water deficit as D5W - if hypovolemic- use NS. Correct 1/2 of water deficit in first 24h then remaining over next 1-2days

Answer 8

99% of K is in ICF so small changes in ECF K has clinical effects - impaired electrical signaling in heart, muscle, nerve. Proper proportion of K and Ca must exist for their exchange across membrane channels that allow electrical conduction to occur Cells act as rapid K buffer. Kidney regulates long term K control

Answer 9

n/v, colic, diarrhea Weakness, paralysis, resp failure Arrhythmia, arrest

Answer 10

N/v Weakness, lethargy, decreased reflexes Hypotension, arrest

Answer 11

Anorexia, n/v, abdominal pain Weakness, confusion, coma, bone pain Hypertension, arrhythmia, polyuria, polydipsia

Answer 12

Ileus, constipation Decreased reflexes, fatigue, weakness, paralysis Arrest

Answer 13

Hyperactive reflexes, muscle tremors, tetany, seizures Arrhythmia

Answer 14

Hyperactive reflexes, paresthesias, carpopedal spasm, seizures HF

Answer 15

Usually too much renal secretion Loss of K due to excess mineralocorticoid activity - Primary hyperaldosteronism, Cushing's, renal artery stenosis, congenital adrenal hyperplasia (will also cause hyperNa) Movement of K into cells due to insulin, catecholamines, alkalemia Prolonged administration of K-free parenteral fluids Total parenteral hyperalimentation with inadequate K replacement Loss of excessive lower GI secretions like diarrhea, colonic fistulas, VIPoma Diuretics

Answer 16

ECG - flattened T waves, ST depression, U wave Arrhythmias, signs of low voltage

Answer 17

Check Mg level first as hypomagnesiemia is commonly associated with hypoK and must be corrected before/along with hypoK. Amount of K to be replaced can be estimated as 4-current K x 100, in mEq (if current K is 3.1, give 90 mEq) If asymptomatic patient with K > 3, oral K may be enough No more than 40 mEq should be added to a liter of IVF since rapid infusion causes fatal arrhythmias Rate should not exceed 40 mEq/hr May cause burning sensation if given in PIV. Using low flow of 10 mEq/hr or adding a small amount of lidocaine to solution can lower discomfort

Answer 18

Usually renal failure Rarely found when renal function is normal and usully causes a transient hyperK due to cellular shifts: K spills from cells in severe injury; cells take up H ions in exchange for intracellular K, acting as a buffer in state of acidosis Drugs - ACE inhibitors, K sparing diuretics Iatrogenic - Penicillin G has 1.7 mEq of K per 1M units, KCl added to maintenance fluids, blood transfusions with old batch of pRBCs where K may have leaked out of cells, overtreatment of hypoK Digoxin - blocks Na-K-ATPase pump Hypoaldosteronism PseudohyperK: Can result when RBCs lyse in test tube and release K. This is lab error. Repeat test.

Answer 19

Cardiac effects most significant. Confirm hyperK and get ECG ECG - early: Peaked T waves, wide QRS, ST depression - late: disappearance of T waves, heart block, sine wave (ominous for impending fatal arrhythmia), cardiac arrest GI - n/v, intermittent intestinal colic, diarrhea

Answer 20

10% CaGluconate 1g IV - monitor ECG. Ca temporarily suppresses cardiac arrhythmias by stabilizing the cardiac membrane and should be given first. Does not effect K load. The membrane of cardiac muscle would abnormally fire in presence of high K. Lower extracellular K (acute treatment): Albuterol, insulin with glucose, or sodium bicarb promote cellular reuptake of K Kayexalate - cation exchange resin. As opposed to above measures, which immediately protect against dangers of high K, this actually removes the K from the body Dialysis (last resort)

Answer 21

Normal: 1,000 - 1,200 mg. Most in bone in form of phosphate and carbonate Normal daily intake = 1-3g Most excreted via stool Normal serum 8.5-10.5 - half of this is nonionized and bound to plasma protein Ionized calcium is the most accurate measure of calcium, but labs report total calcium An additional nonionized fraction (5%) if bound to other substances in ECF Ratio of ionized to nonionized Ca is related to pH Acidosis causes increase in ionized fraction and alkalosis causes decrease in ionized fraction

Answer 22

Correct for low albumin Corrected Ca = 0.8 (Normal albumin - observed albumin) + observed calcium If corrected Ca is within normal range, do nothing

Answer 23

- Acute pancreatitis - Massive soft-tisse infections (nec fasc) - Acute/chronic renal failure - Pancreatic/small bowel fistuals - Hypoparathyroidism (common after parathyroid or thyroid surgery) - Hypoproteinemia - Severe depletion of Mg - Severe alkalosis may elicit symptoms with normal serum levels bc there is a decrease in ionized fraction of total serum Ca

Answer 24

Numbness and tingling of fingers, toes, and around mouth Increased reflexes Chvostek's sign: tapping over facial nerve in front of tragus of the ear causes ipsilateral twitching Trousseau's sign: Carpopedal spasm following inflation of sphygmomanometer cuff to above systolic blood pressure for several minutes Muscle and abdominal cramps Convulsions ECG - prolonged QT interval

Answer 25

IV Ca Gluconate or CaCl2 Monitor QT interval on ECG

Answer 26

Hyperparathyroidism Cancer (esp breast, MM) Drugs (thiazides)

Answer 27

Fatigue, weakness, anorexia, weight loss, n/v Somnambulism (sleepwalking), stupor, coma Severe HA, pain in back and extremities, thirst, polydipsia, polyuria Death

Answer 28

Vigorous volume repletion with salt solution - dilutes Ca and increases urinary Ca excretion - can be augmented with furosemide - definitive tx of acute hypercalcemic crisis in patients with hyperparathyroidism is immediate surgery Treat underlying cause

Answer 29

Gut works but oral intake not possible - AMS, ventilator, oral/pharyngeal/esophageal disorders Oral intake not sufficient for metabolic requirements - anorexia, sepsis, severe trauma/burns Presence of malnutrition and wasting

Answer 30

Enteral feeding not possible - GI obstruction, ileus Enteral intake not enough for metabolic requirements - chronic diarrhea/emesis, malabsorption, fistulas, chemo, irradiation therapy Biggest danger of TPN is infection (organic products in TPN can become infiltrated with bacteria and sent right into the blood) Adjunctive support needed for managing disease - pancreatitis, hepatic failure, renal failure, chylothorax

Answer 31

25 kcal/kg/day

Answer 32

22 kcal/kg/day

Answer 33

BEE x 1.3 - 1.5

Answer 34

BEE x 1.6 - 2

Answer 35

12% increase per degree C over 37

Answer 36

must be met with non-protein calories. 70% carbs. 30% fat

Answer 37

ratio of CO2 released to O2 consumed per unit metabolism of a substrate (VCO2/VO2) Lipid = 0.7 Protein = 0.8 Carb = 1.0 Balanced diet = 0.83

Answer 38

0.8 - 1 g/kg body weight Increases in illness and is maximal in burn patients Avg surg patient needs 1.2-1.6 g/kg Each gram of urinary nitrogen is equivalent to 6.25g of degraded protein Nitrogen balance = (protein intake in g/6.25) - (Urinary urea nitrogen + 4) Goal nitrogen balance should be positive 4-6

Answer 39

Enteral preferred. Reduces infection. May be continuous or intermittent. Routes for GI feeding = PO, NG, gastrostomy, jejunostomy Glutamine is the fuel for enterocytes Short chain fatty acids serve as fuel for the colonocytes Omega 3 fatty acids and arginine serve as immune modulating agents Complications of enteral = diarrhea, aspiration, obstruction of tube

Answer 40

AG > 12 MUDPILES + CAT ``` Methanol/Metabolism (inborn error) Uremia DKA Paraldehyde/ Propylene glycol Iron/Isoniazid/Isopropyl alcohol Lactic acidosis Ethylene glycol Salicylates/strychnine ``` CO, CN- Alcoholic ketoacidosis Toluene 4 basic processes = ketoacidosis, lactic acidosis, renal failure, intoxication

Answer 41

HARDUPS + G ``` Hyperparathyroidism/Hyperalimentation (TPN), hyperparathyroid Adrenal insufficiency/Acetazolamide, Addison's, Ammonium Chloride Renal tubular acidosis*** Diarrhea*** Ureteroenteric fistula Pancreatic fistulas Sprionolactone, Saline Glue sniffing ```

Answer 42

MIS[HAP]3S ``` Mechanical overventilation/MI/Meningitis Increased ICP Sepsis Hypoxemia/Hyperpyrexia/HF Anxiety/Asthma/Ascites Pregnancy/Pain/Pneumonia Salicylates ```

Answer 43

1) pH in relation to 7.4 2) CO2 in relation to 40 Resp acidosis: pH 40 Metabolic acidosis: pH 7.4, CO2 7.4, CO2 > 40

Answer 44

For every change in CO2 of 10, the pH should also change by 0.08 (acute) or 0.04 (chronic) For every change in CO2 of 10, the HCO3 should change by 1 (acute) or 3 (chronic) in direction that brings pH back to normal If we find there's too much HCO3 (over corrected) = coexisting metabolic alkalosis If we find there's too little HCO3 = coexisting metabolic acidosis

Answer 45

1) Is CO2 appropriate? Use Winter's formula (1.5HCO3 + 8 +/- 2). If CO2 > expected from formula, there is also a respiratory acidosis. If CO2 2 = metabolic alkalosis If 1-2, pure anion gap acidosis (lactic acidosis about 1.6, DKA around 1) If

Answer 46

For every change in CO2 of 10, the pH should also change by 0.08 (acute) or 0.04 (chronic) For every change in CO2 of 10, the HCO3 should change by 2 (acute) or 4 (chronic) in direction that brings pH back to normal Too much HCO3? Coexisting metabolic alkalosis Too little? Coexisting metabolic acidosis

Answer 47

1) Urine Cl > 10 = not volume responsive - is there HTN? Yes = hyperaldosteronism, renal artery stenosis. No = Barter's, Gittelman's 2) Urine Cl

Answer 48

Hypoventilation Opiate OD Asthma/COPD with air trapping Muscular strength (long-term ventilators or obese/OSA)