Electrolytes Lecture - Part 3 PDF

Composition of Body Fluids Electrolytes Non-electrolytes Cations: sodium, potassium, hydrogen, magnesium, Glucose, urea, protein, lipids, and creatinine. and calcium. Anions: chloride, bicarbonate, phosphate, and sulfate. Major Electrolytes Electrolyte Norm...

Composition of Body Fluids Electrolytes Non-electrolytes Cations: sodium, potassium, hydrogen, magnesium, Glucose, urea, protein, lipids, and creatinine. and calcium. Anions: chloride, bicarbonate, phosphate, and sulfate. Major Electrolytes Electrolyte Normal Value Na+ 135-145 mEq/L K+ 3.5-5 mEq/L Ca2+ 8.4-10.5 mg/dL Mg2+ 1.5-2.5 mEq/L Cl- 98-106 mEq/L HCO3- 22-26 mEq/L PO4- 2.7-4.5 mEq/L 7 EXTRACELLULAR SODIUM (Na+) Major Cations INTRACELLULAR POTASSIUM (K+)  Hyponatremia/ Hypocalcemia/ Electrolyte hypernatremia Hypercalcemia Imbalances Hypokalemia/ Hyperkalemia Hypophosphatemia/ Hyperphosphatemia Hypomagnesemia/ Hypochloremia/Hyperch Hypermagnesemia loremia Sodium (Na+) 1 Function Major extracellular cation, regulates osmolality and maintains transmembrane electric potential. 2 Regulation Excreted by kidneys, skin, and GI tract. Regulated by thirst, ADH, and aldosterone. 3 Normal Range 135-145 mEq/L  Sodium and Water If sodium intake suddenly increases, extracellular fluid concentration also rises Increased serum Na+ increases thirst and the release of ADH, which triggers kidneys to retain water Aldosterone also has a function in water and sodium conservation when serum Na+ levels are low Sodium-Potassium Pump Sodium Outside Sodium is abundant outside cells and tries to enter. Pump Action Uses ATP, magnesium, and enzymes to maintain concentrations. Potassium Inside Potassium is abundant inside cells and tries to exit.  Hyponatremia Na level  Hyponatremia · Accumulation of water in greater Na dilution (hypervolemic) T – Causes: heart failure, cirrhosis, nephrotic syndrome, hypoalbuminemia, septic capillary leak – S/S: confusion, seizure, edema * restriction salt 14 Hyponatremia Treatment E O Rapid correction → central pontine Irreversible myelinolysis Goal of correction 10-12mEq/L/day - Fluid restriction with SIADH to - for – Infuse hypertonic NaCl solution hyper/isovolemic hyponatremia (3% or 5% NaCl) - - – IV fluids and/or increased po – Furosemide to remove excess - Na+ intake fore hypovolemic fluid hyponatremia Dronea – Monitor client in ICU 17 Treatment Recommendations 1) For mild cases only (serum sodium > 120 meq/L): Water restriction (limit to 500 to 1500 ml/ 24 hours) and furosemide 40-80 IV/ oral once daily (20-400 mg/day). 2) If severe symptomatic hyponatremia is present (sodium level < 115 mEq/L) in the volume over loaded patient: Continue water restriction. Also infuse 3% hypertonic saline. Calculate sodium deficit: 0.6 x (weight in kg) x (desired sodium - Actual sodium) Use 0.5 for females. Desired range= 120 - 125 meq/L. Treatment Recommendations 4)Symptomatic and acute (< 24 hours in duration), the serum sodium may be ⑳ raised safely to 120-125 meq/L in 24 hours or less. 29 5)Symptomatic chronic hyponatremia, or hyponatremia of unknown duration, the serum sodium should be raised⑧ slowly (0.5 meq/L/hr) to about 120-125 meq/L. = ⑳ Why? The total increase in these patients should not exceed 10-12 meq/L in 24 hours hours.  Hypernatremia Na>145mEq/L => Water loss greater than sodium loss – Causes: fever, burns, diabetes insipidus -- – S/S: thirst, confusion, weakness Increase in total body sodium (↑ ECF) – Causes: cushings, hypertonic saline – S/S: thirst, confusion, weakness, ↑ urine sodium  Hypernatremia Treatment – Rate of correction for Na+ 1-2 mEq/L/hr – Calculate water deficit Water deficit = 0.6 x wt (kg) x [(current Na+/140) – 1] – Rate of correction for calculated water deficit 50% of free water in first 12-24 hrs Remaining next 24 hrs 21 Skin flushed Agitation What Do You Think S-A-L-T Low grade fever Thirst See? Neurological symptoms Signs of hypovolemia 22 Correct underlying Monitor for s/s of What Do disorder cerebral edema We Do? Gradual fluid replacement Monitor serum Na+ level Seizure precautions 23 Establish documented onset (acute, < 24 h; chronic, >24h) Acute hypernatremia, correct the serum sodium at an initial rate of 2-3 mEq/L/h (for 2-3 h) Treatment (maximum total, 12 mEq/L/d). Recommendations Measure serum and urine electrolytes every 1-2 hours Perform serial neurologic examinations and decrease the rate of correction with improvement in symptoms 24 Treatment Recommendations Chronic hypernatremia with If a volume deficit and no or mild symptoms should hypernatremia are present, be corrected at a rate not to intravascular volume should exceed 0.5 mEq/L/h and a be restored with isotonic total of 8-10 mEq/d (eg, 160 sodium chloride prior to free- mEq/L to 152 mEq/L in 24 h). water administration. 25 80kg patient; serum sodium=110 meq/L, male; desired target= 120 meq/L. Calculate the sodium deficit? In Class. 0 6 (WT Rg) x Coisines - actuall Activity 480 = 3% hypertonic saline contains 513 Time=5min meq/Liter, so how many ml/ day the patient needs? Calculate the hourly rate in ml/hr? 26 In Class Activity Time=5min 1000 m/ 513- 480-X 835 672 X =. 80kg patient; serum sodium=110 meq/L, male; desired target= 120 meq/L. Calculate the sodium deficit= 480 mEq of Sodium 3% hypertonic saline contains 513 meq/Liter, so how many ml/ day the patient needs? 935.7ml/day of 3% NS 2 Calculate the hourly rate in ml/hr? 39ml/hr Potassium (K+) 1 Function Primary intracellular cation, regulates muscle/nerve excitability and acid/base balance. 2 Regulation Influenced by insulin, glucose, acid/base balance, and renal function. 3 Normal Range 3.5-5 mEq/L Potassium Balance Regulation Intake Dietary potassium ingestion. Na+/K+ Pump Maintains intracellular/extracellular balance. Renal Excretion Kidneys regulate potassium excretion based on serum levels. 29 Sodium/Potassium Uses ATP to pump potassium into Pump cells Pumps sodium out of cells metabol al a semi Creates a balance 30 Renal Regulation Increased K+ Aldosterone levels  secretion causes increased K+ loss Na+ reabsorption in urine and K+ excretion 31 PH 8 Potassium ions and Acidosis  Alkalosis  hydrogen ions hyperkalemia (K+ hypokalemia (K+ exchange freely across moves out of cells) moves into cells) cell membranes Hypokalemia Definition Potassium level