Electrolytes.pdf

Electrolytes Dr. U. Murali. M.S; M.B.A. Learning Outcomes Identify cations & anions of electrolytes List functions of electrolytes Discuss about electrolyte imbalances – What to see & What to do Electrolytes Charged particles in solution Cations (+) Anions (-) Integral part of metabolic and cellular...

Electrolytes Dr. U. Murali. M.S; M.B.A. Learning Outcomes Identify cations & anions of electrolytes List functions of electrolytes Discuss about electrolyte imbalances – What to see & What to do Electrolytes Charged particles in solution Cations (+) Anions (-) Integral part of metabolic and cellular processes Composition of Body Fluids Major Cations EXTRACELLULAR – SODIUM (Na+) INTRACELLULAR – POTASSIUM (K+) What do Electrolytes - Do? Promotes neuromuscular impulses. Maintain body fluid volume & Osmolarity. Distribute body water between fluid compartments. Regulate acid base balance. Electrolyte Imbalances Hyponatremia/ Hypocalcemia/ Hypernatremia Hypercalcemia Hypokalemia/ Hypophosphatemia/ Hyperkalemia Hyperphosphatemia Hypomagnesemia/ Hypochloremia/ Hypermagnesemia Hyperchloremia Hyponatremia Serum Na+ level < 135 mEq/L Deficiency in Na+ related to amount of body fluid Several types – Dilutional – Depletional – Hypovolemic – Hypervolemic – Isovolemic Surgical Causes - Hyponatremia Intestinal obstruction Intestinal fistulas – biliary / duodenal / gastric / pancreatic GOO – severe vomiting Ryle’s tube aspiration Severe diarrhoea – Colitis / colerectal polyps After surgery & trauma – occurs What Do You See ? Sunken eyes, Dry coated tongue, poor skin turgor Headache, N/V, muscle twitching, altered mental status Irritability, neurological symptoms, convulsions , coma What Do We Do? MILD / CHRONIC CASE SEVERE / ACUTE CASE – Na < 115 mEq/ L – Na < 100 mEq/L – Restrict fluid intake for hyper/isovolemic hyponatremia – Infuse hypertonic NaCl solution (3% or 5% NaCl) – IV fluids and/or increased Na+ intake for hypovolemic hyponatremia – Frusemide to remove excess fluid – Monitor client in ICU Hypernatremia Excess Na+ relative to body water Occurs less often than hyponatremia Na > 150 mEq / L When hypernatremia occurs, fluid shifts outside the cells May be caused by water deficit or overingestion of Na+ - Renal dysfuction Also may result from diabetes insipidus, Cardiac failure, Drug – NSAID / Steroids What Do You See ? Think S-A-L-T Skin flushed Agitation Low gradeFirm, fever Thirst Neurological symptoms Signs of hypovolemia What Do We Do? Correct underlying disorder Restrict saline & sodium Gradual / Slow fluid replacement Monitor for s/s of cerebral edema Monitor serum Na+ level Seizure precautions Potassium Major intracellular cation Untreated changes in K+ levels can lead to serious neuromuscular and cardiac problems Normal K+ levels = 3.5 - 5 mEq/L Balancing Potassium Most K+ ingested is excreted by the kidneys Three other influential factors in K+ balance : – Na+/K+ pump – Renal regulation – pH level Hypokalemia Serum K+ < 3.5 mEq/L Caused by – SUDDEN = Pts in Diabetic coma GRADUAL – Diarrhoea – Villous+UC – PS + GOO – Duodenal fistula – Ileostomy / USD – Poisoning – Beta agonists What Do You See? Think S-U-C-T-I-O-N – Skeletal muscle weakness / Slurred speech – U wave (ECG changes) - Arrythmias – Constipation, ileus – Tone – Hypotonia = Sign – I rregular, weak pulse – O rthostatic hypotension – N umbness (paresthesias) Hypokalemia What Do We Do? Increase dietary K+ Oral KCl supplements IV K+ replacement Change to K+-sparing diuretic Monitor ECG changes IV K+ Replacement Mix well when adding to an IV solution bag Concentrations should not exceed 40-60 mEq/L Rates usually 1020 mEq/hr NEVER GIVE IV PUSH POTASSIUM Hyperkalemia Serum K+ > 6 mEq/L Less common than hypokalemia Caused by altered kidney function, increased intake (salt substitutes), blood transfusions, meds (K+-sparing diuretics), cell death (trauma) What Do You See? Irritability Paresthesia Muscle weakness (especially legs) ECG changes (tented / peak T wave) Irregular pulse Hypotension Nausea, abdominal cramps, diarrohea What Do We Do? Mild – Loop diuretics (Lasix) – Dietary restriction Moderate – Cation-exchange resin such as Kayexalate (act by exchanging the cations in the resin for the potassium in the intestine) potassium is then excreted in the stool Emergency – 10% calcium gluconate for cardiac effects – Sodium bicarbonate for acidosis Calcium 99% in bones, 1% in serum and soft tissue (measured by serum Ca++) Works with phosphorus to form bones and teeth Role in cell membrane permeability Affects cardiac muscle contraction Participates in blood clotting Normal value 8.5 – 10.5 mg/dl Hypocalcemia Serum calcium < 8.9 mg/dl Caused by inadequate intake, malabsorption, pancreatitis, thyroid or parathyroid surgery, loop diuretics, low magnesium levels What Do You See? Neuromuscular – Anxiety, confusion, irritability, muscle twitching, paresthesias (mouth, fingers, toes), tetany, carpopedal spasms Fractures Diarrohea Diminished response to digoxin EKG changes TESTS USED TO ELICIT SIGNS OF CALCIUM DEFICIENCY What Do We Do? Calcium gluconate for postop thyroid or parathyroid client Cardiac monitoring Oral or IV calcium replacement Hypercalcemia Serum calcium > 10.1 mg/dl Two major causes – Cancer – Hyperparathyroidism What Do You See? Fatigue, confusion, lethargy, coma Muscle weakness, hyporeflexia Bradycardia  cardiac arrest Anorexia, nausea/vomiting, decreased bowel sounds, constipation Polyuria, renal calculi, renal failure CLINICAL MANIFESTATIONS OF HYPERCALCEMIA Constipation Cardiac Dysrhythmias Nausea Decreased GI Motility Mental status changes: lethargy, confusion, memory loss CLINICAL MANIFESTATIONS OF HYPERCALCEMIA Calcium accumulates in the ECF and passes through the kidneys Immobilization Calcium Stones Bone Demineralization Ca Precipitation What Do We Do? If asymptomatic, treat underlying cause Hydrate the patient to encourage diuresis Loop diuretics Corticosteroids Magnesium Cofactor for many enzymes – ATP utilisation in muscle fiber Role in protein synthesis & carbohydrate metabolism Helps cardiovascular system function (vasodilation) Regulates muscle contractions Hypomagnesemia Serum Mg++ level < High risk clients 1.5 mEq/L – Chronic alcoholism – Malabsorption Caused by poor – GI/urinary system dietary intake, poor GI disorders absorption, excessive – Sepsis GI/urinary losses – Burns – Wounds needing debridement What Do You See? CNS Neuromuscular – Altered LOC – Muscle weakness – Confusion – Leg/foot cramps – Hallucinations – Hyper DTRs – Tetany CLINICAL MANIFESTATIONS OF HYPOMAGNESEMIA DEPRESSION CONFUSION TETANY CRAMPS CONVULSIONS What Do You See? Cardiovascular Gastrointestinal – Tachycardia – Dysphagia – Hypertension – Anorexia – ECG changes – Nausea/vomiting What Do We Do? Mild – Dietary replacement Severe – IV or IM magnesium sulfate Monitor – Neuro status – Cardiac status – Safety Mag Sulfate Infusion Use infusion pump - no faster than 150 mg/min Monitor vital signs for hypotension and respiratory distress Monitor serum Mg++ level q6h Cardiac monitoring Calcium gluconate as an antidote for overdosage Hypermagnesemia Serum Mg++ level > 2.5 mEq/L Not common Renal dysfunction is most common cause – Renal failure – Addison’s disease – Adrenocortical insufficiency – Untreated DKA What Do You See? Decreased neuromuscular activity Hypoactive DTRs Generalized weakness Occasionally nausea/vomiting What Do We Do? Increased fluids if renal function normal Loop diuretic if no response to fluids Calcium gluconate for toxicity Mechanical ventilation for respiratory depression Hemodialysis (Mg++-free dialysate) References Bailey & Love’s - Short Practice of Surgery 24th edition. Internet websites.