Fluid and Electrolyte Imbalance

1. Fluid and Electrolyte Imbalance

2. Water constitutes 60% of the total body weight in adult Younger adults have more fluid than elder Muscle skin and blood have the highest amount of fluid The fluid in the body is located in 2 fluid compartments intracellular and extracellular The intracellular compartment have 2/3 of the total body fluid.

3. The extracellular fluid is divided into the intravascular, interstitial and transcellular. • The total volume of blood is 6 L . About 3 L is plasma while the other 3L is cells. • ThE INTERSTEIAL fluid suround the cells and it is about 11-12L . • Lymphatic fluid is interstetial fluid • The transcellular fluid is about 1L and examples are cerebrospinal fluid CSF, Pericardial synovial, intraocular and pleural fluid. • Fluid move between different compartments to maintain equilibrium • Loss of extracellular fluid into a space the does not contribute to this equilibrium is called third space • Examples of third space are ascitis, burn, perotonitis, bowel obstruction.

4. Regulation of body fluid and electrolyte • Different mechanisms that include: • osmosis : movement of water from the lower solute concentration to the higher solutes concentration • diffusion: substance move from the higher concentration to the lower concentration • filtration: substance move from area of high hydrostatic pressure to area of low hydrostatic pressure • Sodium potassium pump: keep stable concentration of sodium and potassium • Active transport: movement of substance against concentration gradient

5. Route of fluid loss and gain • Kidney: kidney produce 1-2L of urine/ day or 1ml/kg/hr • Skin: evaporation about 600ml /day and sweat • Lung: water vapor 400ml/d • Gatrointestinal tract 100-200ml/ d • Different organs take parts in fluid and electrolyte balance: kidney, lung, pituitary gland, adrenal gland, heart and blood

6. Hypovolemia • Water and electrolyte loss in same proportion • Caused either by increase loss such as bleeding, vomiting diarrhea , suctioning sweat… or decrease intake. • Clinical manifestations include: hypotension, weight loss, weak rapid heart rate, flat neck vein, cool skin, thirst • Assessment and diagnostic findings: elevated blood urea nitrogen BUN –creatinine value to more than 20-1 • Elevated hematocrit level • Urine specific gravity( normal value 1.003-1.030 • Increase urine osmolarity greater than 450mOsm/kg (normal 250-900mOsm/kg) • Hypokalemia, hyperkalemia, hyponatremia and hypernatremia depending on the cause

7. Hypovolemia management : Isotonic SOLUTION such as NS 0.9% In some cases of sever fluid loss hypotonic solution NS0.45% can be given to provide fluid to the dehydrated cells Nursing management report oligurea( decrease urine output of less than 30cc/hr

8. Hypervolemia • Isotonic expansion of extracellular fluid • Causes: heart failure, renal failure, liver cirrhosis, and excessive table salt and sodium containing fluid IV administration • Clinical manifestations: edema, distended neck vein, abnormal lung sound (crackles) increase blood pressure, increase weight, increase urine outputdiagnostic findings • Elevated urea (BUN) and hematocrit • Increase urine sodium • Patient may have pulmonary congestion

9. Management of hypervolemia • Diuretics furosemide ( lasix), Thiazides as hydrochlorothiazide • Hemodialysis • Restriction of sodium ( 250mg/day)