Fluid and Electrolyte Imbalance Lecture 2 9152021 1

Fluid and Electrolyte Imbalance Lecture 2 9/15/2021 1

Sodium Imbalance • Normal value ( 135 -145 m. Eq/L) • Sodium is a primary determinant of serum osmolarity. Increase in sodium lead to increase osmolarity • Sodium also has a major role in water distribution. Sodium and water usually are lost and gained together • Sodium is important in creation and transmission of nerve impulse and muscle contraction 9/15/2021 2

• Sodium deficit ( Hyponatremia): defined as sodium level below 135 m. Eq/L Can happened in 2 cases : • Loss of sodium from blood in a proportion that is higher than loss of water • Significant increase in water with no change in sodium content ( dilution hyponatremia) • Hyponatremia can happened in both hypervolemia and hypovolemia 9/15/2021 3

Causes of hyponatremia • Vomiting, sweating, diarrhea, fistula, use of diuretics if combined with loss sodium intake • Deficiency of aldosterone • ( up normal) Increase anti diuretic hormone( ADH) such as in syndrome of inappropriate antidiuritic hormone ( SIADH). 9/15/2021 4

Clinical manifestations of hyponatremia • With minor change Poor skin turgor, headache, dry mucosa, orthostatic hypotension • With a level of less than 115 m. Eq/L neurologic changes such as alteration in mental status, increase intracranial pressure seizure and coma. • Hyponatremia results in accumulation of water in brain tissue ( cerebral edema) due to osmotic gradient. 9/15/2021 5

Diagnostic findings in hyponatremia • Decrease serum sodium ( less than 135 m. Eq/L) • Decrease urine sodium to less than 20 m. Eq/L as the kidney try to conserve sodium • Low urine specific gravity (1. 002 -1. 004) 9/15/2021 6

Management of hyponatremia • Sodium replacement : increase oral intake • Normal saline 0. 9% or Ringer Lactate IV • Sodium should not be increased in a rate higher than 12 m. Eq/L • Water restriction less than 800 ml/24 hrs in case of fluid excess such as (SIADH) 9/15/2021 7

Sodium excess (Hypernatremia ) • High serum sodium more than 145 m. Eq/L • Cause by increase is sodium in different proportion than water • Can happened in both hypervolemia and hypovolemia Causes Decrease fluid intake ( especially in unconscious patient). Administration of hypertonic saline solution Drowning in sea water 9/15/2021 8

Clinical manifestation of hypernatremia • Neurologic manifestation as a result of increase plasma osmolarity and movement of water out of the cells. • Restlessness, weakness, delusion hallucination • Thirst Assessment and diagnostic findings Increase sodium higher than 145 m. Eq/L and serum osmolarity higher than 300 m. Osm/kg 9/15/2021 9

Medical management of hypernatremia • Administer hypotonic saline solution such as NS 0. 45% • Sodium level is reduced in a rate no faster than 0. 5 to 1 m. Eq/L/ hr 9/15/2021 10

Potassium Imbalance • Normal value in serum is 3. 5 -5 m. Eq/L • Potassium is a major intracellular electrolyte • Influence both cardiac and skeletal muscle activity • Potassium is very sensitive to change in serum level • Kidney is the primary regulator of serum potassium with 80% excretion through kidney while the other 20% is excreted via bowle and sweat 9/15/2021 11

Potassium Deficit (Hypokalemia) • Decrease in serum potassium less than 3. 5 m. Eq/L • Causes include diuretics, Gastrointestinal loss as in vomiting and diarrhea, illeostomy. • Increase aldosteron secretion • Diuretics ( lasix) • Increase insulin secretion as in diabetes I insulin increase entry of insulin into skeletal muscle and hepatic mucles 9/15/2021 12

Clinical manifestations of hypokalemia • Fatigue, anorexia, nausea • Muscle weakness, paresthesia, decrease bowel motility • Inability of kidney to excrete urine • Increase sensitivity to digitalis( digoxin) • Electrocardiogram (ECG) changes flat T wave, inverted T wave, depressed ST segment elevated U wave 9/15/2021 13

Medical management of hypokalemia • Potassium supplement: usually 40 -80 m. Eq/L • High potassium diet as most fruits, legume, whole grain, milk, meat. • Potassium chloride is a routine supplement and usually the concentration is 20 m. Eq 40 m. Eq/ for each liter 9/15/2021 14

Potassium Excess (Hyperkalemia) • Potassium decrease less than 3. 5 m. Eq/L Causes • mainly is decrease renal excretion ( renal failure). • Decrease aldosteron secretion. • Side effect of medications such as heparin, ACE inhibitor (captopril), NSAID, potassium sparing diuretic such as spironalacton( aldacton) 9/15/2021 15

Clinical manifestations of hyperkalemia • The most common is cardiac when the level is higher than 7 m. Eq/L and early changes can be noted at a value 6 m. Eq/L such as: • Peaked narrow T wave • St segment depression • Shortened QT interval • PR interval prolonged followed by disappearance of P wave. • Prolongation of QRS complex that entails cardiac arrhythmia and cardiac arrest • Muscle weakness may be paralysis related to depolarization block ( speech muscle and respiratory muscle 9/15/2021 16

Medical management of hyperkalemia • Restriction of potassium • Cation exchange resin ( Kayexalate): bind with potassium in the intestine and removed through stool. • Administration of calcium gluconate ( to protect the heart but has no effect on the potassium level) • Administration of sodium bicarbonate • Administration of hypertonic dextrose solution with insulin: insulin bind potassium and sugare and move it to the cells 9/15/2021 17

Calcium Imbalance • 99% of the total body calcium in the skeletal system • Normal serum value for the total calcium is 8. 6 -10. 2 mg/dl ( 2. 2 -2. 6 mmol/L). • The ionized calcium 4. 5 - 5. 1 mg/dl) ( the lap give readings for both ionized and total) • Calcium is absorbed in the food in the presence of gastric acidity and vitamin D • Excretion mainly via feces with the reminder through urine 9/15/2021 18

Calcium deficit ( Hypocalcemia) • Lower than 4. 5 - 5. 1 mg/dl for the ionized or lower than 8. 6 mg/dl for the total • Causes include hypoparathyroidism ( decrease parathormon cause less release of calcium from the bone) • Inflammation of pancreas( pancreatitis) • Renal failure ( because of increase in phosphate cause decrease in calcium) • Inadequate vitamin D consumption 9/15/2021 19

Clinical manifestations of hypocalcemia • Increase neuronal excitability resulting in Tetany: increase both sensory and motor peripheral nerve discharge. Symptoms of tetany include general tingling in fingers and feet, face, and around mouth • Trousseau’s sign • Chvostek’s sign • Mental changes then Seizure • ECG changes such as prolonged QT interval, prolonged St SEGMENT 9/15/2021 20

• Diagnostic findings of hypocalcemia • Serum calcium level and serum albumin level (because significant amount of calcium in blood is bonded to albumin) • Medical management • Increase dietary intake( milk, green leafy vegetables, canned salmon, sardines, and oyster • IV supplement as calcium gluconate, or calcium chloride • Vitamin D therapy ( increase absorption from the GIT 9/15/2021 21

Calcium Excess ( Hypercalcemia) • Increase total calcium higher than 10. 2 mg/dl or ionized calcium higher than 5. 1 mg/dl. • Causes include malignancy and hyperparathyroidism ( increase parathormone) • Clinical Manifestations • Increase calcium lead to suppress neuronal activity at the neuromuscular junction which cause muscle weakness, incoordination, anorexia, and constipation. • Increase urine output due to disturbed renal function • Cardiac standstill in sever case when calcium is higher than 18 mg/dl 9/15/2021 22

Medical management of hypercalcemia • Administer high volume of NS 0. 9% to dilute the serum and increase urine output • Phosphate may be given as it increase calcium excretion • Lazix rarely given as it increase excretion • Also rarely Calcitonin may be given as it move calcium from the blood to the bone. 9/15/2021 23