Electrolytes Flashcards
VOLUME AND OSMOTIC REGULATION
Na+, K+, Cl-
MYOCARDIAL RHYTHM AND CONTRACTILITY
K+, Ca++, Mg++
COFACTORS IN ENZYME ACTIVATION
Ca++, Mg++, Zn, Cl-, K+
REGULATION OF ATPase ION PUMPS
Mg++
NEUROMUSCULAR EXCITABILITY
K+, Ca++, Mg++
PRODUCTION AND USE OF ATP
Mg++, PO4
ACID BASE BALANCE
HCO3, K+, Cl-, PO4
MAJOR EXTRACELLULAR CATION
SODIUM
MAJOR CONTRIBUTOR OF OSMOLALITY OR
OSMOTIC PRESSURE (Na+, Cl-, HCO3)
SODIUM
IT IS ESSENTIAL FOR TRANSMITTING NERVE
IMPULSES
SODIUM
SODIUM REFERENCE VALUE
135 - 145 mmol/L
SODIUM REABSORPTION AND
POTASSIUM EXCRETION IN THE DISTAL TUBULE
ALDOSTERONE
REMOVES EXCESS SODIUM
ATRIAL NATRIURETIC FACTOR (ANF)
Causes of hypernatremia (3)
Excess water loss
Decreased water intake
Increase intake or retention
Causes of hyponatremia (3)
Increased sodium loss
Increased water retention
Water imbalance
MAJOR INTRACELLULAR CATION
POTASSIUM
INTEGRAL PART OF TRANSMISSION OF NERVE IMPULSE
POTASSIUM
THE SINGLE MOST IMPORTANT ANALYTE IN TERMS OF AN ABNORMALITY BEING IMMEDIATELY LIFE THREATENING
POTASSIUM
Causes of hyperkalemia (4)
DECREASED RENAL
EXCRETION
INCREASED INTAKE
CELLULAR SHIFT
ARTIFACTUAL
Causes of hypokalemia (3)
Gastrointestinal loss
Renal loss
Cellular shift
MAJOR EXTRACELLULAR ANION
CHLORIDE
CHIEF COUNTERION OF SODIUM
Chloride
ONLY ANION TO SERVE AS AN ENZYME ACTIVATOR (AMYLASE)
Chloride
EXCRETED IN URINE AND SWEAT
Chloride
HIGH HCO3 (METABOLIC ACIDOSIS)=
Low chloride
Causes of hyperchloremia (5)
- RENAL TUBULAR ACIDOSIS
- DIABETES INSIPIDUS
- SALICYLATE INTOXICATION
- PRIMARY HYPERPARATHYROIDISM
- METABOLIC ACIDOSIS
Causes of hypochloremia (4)
- PROLONGED VOMITING
- ALDOSTERONE DEFICIENCY
- METABOLIC ALKALOSIS
- SALT-LOSING NEPHRITIS
Participate in BLOOD COAGULATION, ENZYME ACTIVATION,EXCITABILITY OF CARDIAC AND SKELETAL MUSCLE
Calcium
FORMS OF CALCIUM (3)
IONIZED CALCIUM (50%), PROTEIN-BOUND CALCIUM (40%), COMPLEXED WITH ANIONS (10%)
FACTORS AFFECTING SERUM CALCIUM: (3)
- 1,25 DIHYDROXYCHOLECALCIFEROL [1,25-(OH)2-D3]
- PTH
- CALCITONIN
Causes of hypercalcemia (6)
- PRIMARY HYPERPARATHYROIDISM
- CANCER
- ACIDOSIS
- INCREASED VITAMIN D
- SARCOIDOSIS
- HYPERTHYROIDISM
HYPOCALCEMIA (7)
- ALKALOSIS
- RENAL DISEASE
- PRIMARY HYPOPARATHYROIDISM
- ACUTE PANCREATITIS
- HYPERMAGNESEMIA AND
HYPOMAGNESEMIA - MALABSORPTION SYNDROME
- VITAMIN D DEFICIENCY
INVERSELY RELATED TO CALCIUM
PHOSPHOROUS
THE ONLY ELECTROLYTE THAT REQUIRES FASTING
Phosphorous
IS ESSENTIAL FOR THE INSULIN-MEDIATED ENTRY OF GLUCOSE INTO
CELLS BY A PROCESS INVOLVING PHOSPHORYLATION OF THE GLUCOSE AND THE
CO-ENTRY OF POTASSIUM
Phosphorous
PHOSPHATE DEFICIENCY CAN LEAD TO
ATP DEPLETION
Causes of hyperphosphatemia (5)
- HYPOPARATHYROIDISM
- CHRONIC GLOMERULONEPHRITIS
- LYMPHOBLASTIC LEUKEMIA
- MILK-ALKALI SYNDROME
- PAGET’S DISEASE
Causes of hyperphosphatemia (5)
- ALCOHOL ABUSE
- PRIMARY HYPERPARATHYROIDISM
- AVITAMINOSIS D
- OSTEOMALACIA
- MALABSORPTION SYNDROME
INTRACELLULAR CATION SECOND IN ABUNDANCE TO POTASSIUM
Magnesium
FOURTH MOST ABUNDANT CATION IN THE BODY
Magnesium
A CARDIAC ION; REGULATES MOVEMENT OF POTASSIUM ACROSS MYOCARDIUM
Magnesium
Causes of hypermagnesemia (4)
- DIABETIC COMA
- ADDISON’S DISEASE
- CHRONIC RENAL FAILURE
- INCREASED INTAKES OF ANTACIDS,
ENEMAS, AND CATHARTIC
Causes of hypomagnesemia (5)
- ACUTE PANCREATITIS
- MALNUTRITION
- MALABSORPTION SYNDROME
- CHRONIC ALCOHOLISM
- SEVERE DIARRHEA
2ND MOST ABUNDANT ANION IN THE ECF
BICARBONATE
IT ACCOUNTS FOR 90% OF THE TOTAL CO2 AT
PHYSIOLOGIC pH.
BICARBONATE
IT IS THE MAJOR COMPONENT OF THE
BUFFERING SYSTEM IN THE BLOOD
BICARBONATE
IT DIFFUSES OUT THE CELL IN EXCHANGE FOR CHLORIDE TO MAINTAIN IONIC CHARGE NEUTRALITY WITHIN THE CELL (CHLORIDE
SHIFT)
BICARBONATE
IT BUFFERS EXCESS HYDROGEN ION BY
COMBINING WITH ACID
BICARBONATE
DIFFERENCE BETWEEN THE UNMEASURED ANIONS AND UNMEASURED CATIONS
ANION GAP
IT IS CREATED BY THE CONCENTRATION DIFFERENCE BETWEEN THE COMMONLY MEASURED CATIONS (Na+, K+) AND COMMONLY MEASURED ANIONS (Cl-, HCO3)
ANION GAP
IT IS USEFUL IN INDICATING AN INCREASE IN ONE OR MORE OF THE UNMEASURED ANIONS IN THE SERUM AND ALSO AS A FORM OF QUALITY CONTROL FOR THE ANALYZER USED TO MEASURE THESE ELECTROLYTES.
ANION GAP
FORMULAS for ANION GAP (2) and normal values
Anion Gap = Na+ - (Cl- + HCO3) N.V.: 7-16 mmol/L
Anion Gap = (Na+ + K+) - (Cl- + HCO3) N.V.: 10-20 mmol/L
Anion gap is INCREASED in
UREMIA/RENAL FAILURE (PHOSPHATE AND SULFATE RETENTION)
KETOACIDOSIS (STARVATION OR DIABETES)
POISONING BY METHANOL, ETHANOL, ETHYLENE GLYCOL OR SALICYLATE
LACTIC ACIDOSIS
HYPERNATREMIA
INSTRUMENT ERROR
Anion gap is decreased in
HYPOALBUMINEMIA, HYPERCALCEMIA
