fluids and electrolytes assignment
TRANSCRIPT
FLUID BALANCE
TOTAL BODY WATER (AS PERCENTAGE OF BODY WEIGHT) IN RELATION TO AGE AND SEX
AGE MALE FEMALE
UNDER 18 65% 55%
18-40 60% 50%
40-60 50-60% 40-50%
OVER 60 50% 40%
Ions
NORMAL VALUES AND MASS CONVERSION FACTORS
Normal Plasma Values Mass Conversion
Sodium (Na+) 135 – 145 meq/L 23 mg = 1 meq
Potassium (K+) 3.5 – 5.0 meq/L 39 mg = 1 meq
Chloride (Cl-) 98 – 107 meq/L 35 mg = 1 meq
Bicarbonate (HCO3-) 22 – 26 meq/L 61 mg = 1 meq
Calcium (Ca2+) 8.5 – 10.5 mg/dL 40 mg = 1 mmol
Phosphorus 2.5 – 4.5 mg/dL 31 mg = 1 mmol
Magnesium (Mg2+) 1.8 – 3.0 mg/dL 24 mg = 1 mmol
Osmolality 285 – 295 mosm/kg265 - 305 mosm/kg
-
Sodium Regulation
NORMAL Na+
INCREASED SODIUM
DECREASED SODIUM
Increased ADH secretion, Decreased urine volume and increased plasma
volume
Decreased aldosterone secretion, decreased sodium reabsorption
DECREASED SODIUM
INCREASED SODIUM
Decreased ADH secretion, Increased urine volume and decreased plasma
volume
Increased aldosterone secretion, increased sodium reabsorption
Potassium Regulation
NORMAL K+
INCREASED POTASSIUM
DECREASED POTASSIUM
Increased aldosterone secretion with increased potassium secretion by the kidneys and increased potassium in
urine
DECREASED POTASSIUM
INCREASED POTASSIUM
Decreased aldosterone secretion with decreased potassium secretion by the
kidney and decreased potassium in the urine
Calcium Regulation
NORMAL Ca++
INCREASED CALCIUM
DECREASED CALCIUM
Increased Calcitonin secretion with decreased bone resorption
Decreased parathyroid hormone secretion with decreased bone resorption, decreased intestinal
calcium absorption, and decreased kidney calcium reabsorption
DECREASED CALCIUM
INCREASEDCALCIUMIncreased parathyroid hormone
secretion with increased bone resorption, increased intestinal
calcium absorption, and increased renal calcium reabsorption
Parenteral Solutions
COMMONLY USED PARENTERAL SOLUTIONS
IV Solutions Osmolality(mosm/kg)
Glucose(g/liter)
Sodium(meq/liter)
Chloride(meq/liter)
5% D/W 252 50 - -
10% D/W 505 100 - -
50% D/W 2525 500 - -
0.45% NaCl 154 - 77 77
0.9% NaCl 308 - 154 154
3% NaCl 1026 - 513 513
Ringer’s lactate 282 - 130 109
5% D/NR 294 50 147 147
5% D/NM 290 50 77 77
Hyponatremia
SERUM OSMOLALITY
Normal Low High
ISOTONICHyponatremia
HyperproteinemiaHyperlipidemia
HYPERTONICHyponatremia
HyperglycemiaMannitol, sorbitol,Glycerol, maltose
HYPOTONICHyponatremia
VOLUME STATUS
Hyponatremia
VOLUME STATUS
Hypovolemic Euvolemic Hypervolemic
Una <10 meq/LExtrarenal saltDehydrationDiarrheaVomiting
Edematous states:Congestive heart failureHepatic diseaseNephrotic syndromeAdvanced CHF
SIADHPostop HypoNaHypothyroidismPsychogenic polydipsiaBeer potomaniaDrug reactions
Una >20 meq/LRenal salt lossDiureticsACE-inhibitorsNephropathiesMineralo-Corticoid lack
Hypokalemia: Treatment
ORAL POTASSIUM REPLACEMENTS
AMOUNT meq OF K ANION NAMES
LIQUIDS 15 ml 10 Cl 5% Potassium chloride
15 ml 20 Cl 10% Potassium chloride
15 ml 40 Cl 20% Potassium chloride
15 ml 20 Gluconate Potassium gluconate
POWDERS Packet 15 Cl K-lor
Packet 20 Cl Potassium chloride
Packet 25 Cl K-lyte
TABLETS 1 8 Cl Slow-K
1 8 Cl Micro-K extencaps
1 10 Cl K-dur 10
1 20 Cl K-dur 20
Hypokalemia: Treatment
POTASSIUM CONTENT OF FOODS
VERY HIGH(12-20 meq)
HIGH(5-12 meq)
BEANS Garbanzo beansSoy beans
Kidney beans Navy beansLima beans Pinto beans
FRUIT (1/2 cup or as stated) Papaya (one medium) Apricots (3 halves)Banana (6”)Cantaloupe (1/4”)Honeydew melon (1/4”)Orange (3”) and orange juicePear (one large)Prunes (4) and prune juiceRhubarb
Hypokalemia: Treatment
POTASSIUM CONTENT OF FOODS
VERY HIGH(12-20 meq)
HIGH(5-12 meq)
VEGETABLES (1/2 cup or as stated)
Artichoke (one)Avocado (1/4)Brussel sproutsCarrot (7 ½”) and chardKetchup (1 tbsp)Potato (one baked, one broiled, 10 fries, ½ cup mashed)Pumpkin and spinachTomato (one) and tomato juice
Hyperkalemia: Treatment
EMERGENCY TREATMENT OF HYPERKALEMIA
MODALITY MECHANISM OF ACTION
ONSET DURATION PRESCRIPTION K REMOVED FROM BODY
Calcium Antagonizes cardiac conduction abnormalities
0-5 min 1 hour Ca gluconate 10%, 5-30 ml IV;CaCl 5%, 5-30 ml IV
None
Bicarbonate Shifts K into cells
15-30 min
1-2 hours NaHCO3 44-88 meq IV
None
Insulin Shifts K into cells
15-60 min
4-6 hours SAI, 5-10 u IV, plus glucose 50%, 25 g IV
None
Albuterol Shifts K into cells
15-30 min
2-4 hours Nebulized albuterol, 10-20 mg in 4 ml saline
None
Hyperkalemia: Treatment
NON-EMERGENCY TREATMENT OF HYPERKALEMIA
MODALITY MECHANISM OF ACTION
DURATION OF TREATMENT
PRESCRIPTION K REMOVED FROM BODY
Loop diuretic Increased renal K excretion
0.5-2 hours Furosemide 40-160 mg IV or orally with or without NaHCO3, 0.5-3 meq/kg daily
Variable
Sodium polystyrene sulfonate (Kayexalate
Ion exchange resin binds K
1-3 hours Oral: 15-30 g in 20% sorbitol (50-100 ml)Rectal: 50 g in 20% sorbitol
0.5-1 meq/g
Hemodialysis Extracorporeal K removal
48 hours Blood flow > 200-300 ml/min; Dialysate K = 0
200-300 meq
Peritoneal dialysis
Peritoneal K removal
48 hours Fast exchange, 3-4 L/hr 200-300 meq
Hypocalcemia: Treatment
TREATMENT OF HYPOCALCEMIA
MODALITY AMOUNT OF CALCIUM ONSET DOSE
Intravenous calcium (Calcium gluconate)
93 mg (4.7 meq) per 10 ml Immediate 93-186 mg over 10-15 mins; then 10-15 mg/kg over 4-6 hours.
Oral calcium (calcium carbonate)
40% elemental calcium;250 mg/624 mg tablet or
500 mg/1250 mg tablet or500 mg/1500 mg tablet
< 1 hour 250-500 mg calcium 3 to 5 times a day.
Hypercalcemia
CAUSES OF HYPERCALCEMIA
INCREASED INTAKE OR ABSORPTION
Milk-alkali syndrome
Vitamin D or vitamin A excess
ENDOCRINE DISORDERS Primary and secondary hyperparathyroidism
Acromegaly
Adrenal insufficiency
NEOPLASTIC DISEASES Tumors producing PTH-related proteins
Metastases to bone
Lymphoproliferative disease
Secretion of prostaglandins and osteolytic factors
MISCELLANEOUS CAUSES Thiazide diuretics and renal transplant complications
Sarcoidosis and Paget’s disease of the bone
Hypophosphatasia, immobilization, iatrogenic
ABG Interpretation
SUMMARY OF EXPECTED COMPENSATION FOR SIMPLE ACID-BASE DISORDERS
DISORDER INITIAL CHANGE COMPENSATORY RESPONSE
Metabolic Acidosis Decrease in HCO3- Decrease in pCO2:
Δ pCO2 = 1.1 – 1.3 (ΔHCO3-)
Metabolic Alkalosis Increase in HCO3- Increase in pCO2:
Δ pCO2 = 0.6 – 0.7 (ΔHCO3-)
Respiratory Acidosis Increase in pCO2 Increase in HCO3-
ACUTE: ΔHCO3-= 0.1 Δ pCO2 + 2
CHRONIC: ΔHCO3-= 0.3 – 0.35 Δ pCO2
Respiratory Alkalosis Decrease in pCO2 Decrease in HCO3-
ACUTE: ΔHCO3-= 0.2 – 0.25 Δ pCO2
CHRONIC: ΔHCO3-= 0.4 – 0.5 Δ pCO2