This document summarizes fluid, electrolyte and acid-base balance. It discusses total body fluid volumes and water balance, fluid compartments, intravascular fluid volume, movement of body fluids through filtration, osmosis and diffusion, and factors affecting fluid and electrolyte movement like osmotic pressure and tonicity. It also covers electrolytes in the extracellular fluid, sodium regulation, water regulation, manifestations of fluid and electrolyte imbalances, and acid-base balance.

1. Fluid, Electrolyte and Acid-Base Balance

2. Total Fluid Volumes by Age and Sex

3. Normal Water Balance Intake: Fluid ingestion 60% Foods 30% Metabolism 10% Output: Urine 60% Sweat 8% Feces 4% "Insensible" loss 28% (skin, lungs)

4. Fluid Compartments Extracellular Interstitial Intracellular Intravascular Intracellular

5. Fluid is in both compartments 50-60% of body weight ¾ of ECF ¼ of ECF

6. Intravascular Fluid or Plasma (1/4 of ECF) Volume Necessary for BP Maintenance Maintenance of Proportional Distribution Protein content of blood (Serum proteins- globulin and albumin Integrity of blood vessels linings Hydrostatic pressure inside blood vessels Osmolarity Concentration of dissolved substances expressed in mOsm/L (Normal 280-300)

7. Movement of Body Fluids Filtration Hydrostatic pressure Osmosis Concentration- solvent moves to make concentrations even although volume is not. Diffusion Redistributing - high to low to make even Active Transport Energy requirement for selective admission

8. Filtration

9. Osmosis Movement of fluid through semipermeable membrane Concentration controls- solvent moves to make concentrations even although volume is not

10. Filtration Pressures in a Capillary

11. Problem Examples: Edema Congestive heart failure

12. Diffusion - movement of solutes against a concentration gradient; tries to to balance cations + with anions -

13. Active Transport Requires energy from metabolism to move larger or uneven substances across cell membranes Glucose needs insulin to enter cell Na/K pump

14. Active Transportation of Glucose

15. Na-K Pump: For every molecule of ATP, 3 molecules of Na move to outside of cell and 3 molecules of K move inside the cell

16. Factors Affecting Fluid & Electrolyte Movement Osmotic Pressure and Tonicity Hydrostatic Pressure Filtration Pressure

17. Osmolality and Tonicity Osmolality (Kg) and osmolarity (L) are determined by the solutes (mainly Na) in the ECF Abnormalities tell us that there are problems with water regulation in the ECF. Tonicity is the force that the ECF solutes (mainly Na) have to pull water into the ECF. (Na, glucose, mannitol, sorbitol are effective osmoles.)

18. Osmosis and Tonicity Na is the main determinant of plasma tonicity . Thirst and ADH release Swelling of cells

19. Problem Examples: Edema Congestive heart failure

20. Tonicity HYPO 0.45% saline (1/2 normal) Moves fluid into cells

21. Tonicity ISO Same osmolarity as plasma 0.9 % saline (Normal saline) – no fluid shift

22. Tonicity HYPER 3% saline Pulls fluid from cells

23. Tonicity

24. Electrolytes + - - - - - + + + +

26. ECF Electrolytes Sodium - Na 135-145mEq/L Potassium - K 3.5-5.0 mEq.L Calcium - Ca 4.5-5.5 mEq/L Magnesium - Mg 1.5 - 2.5 mEq/L Chloride - Cl 90-110 mEq/L Bicarbonate – HCO 3 Arterial 22-26 mEq/L Venous 24-30 mEq/L

27. Sodium and ECFV The total amount of Sodium in ECF is the major determinant of the size of the ECF Volume Na increases = ECFV increases until ECF ‘volume overload’ results (edematous states) CHF, Cirrhosis of the liver, nephrotic syndrome Pleural effusions, pulmonary edema, ascites Na decreases = ECFV decreases eventually leading to ‘volume depletion’ manifested by poor skin turgor, tachycardia, orthostatic hypotension

28. Sodium Regulation Kidney receptors sense changes in renal perfusion causing renin-angiotensin system to retain sodium in kidney. Volume receptors in great veins sense filling and release atrial natriuretic factor that promotes Na excretion. Pressure receptors in aorta and carotid sinus activate sympathetic NS to retain Na . Water ALWAYS follows Na Therefore when ECFV increases, these mechanisms are activated to increase Na excretion; and conversely, if ECFV decreases, the same means promotes Na retention.

29. Water Regulation ( Hypo- and Hyper-Natremia are always a problem with water, not Sodium) Osmolality increase in ECF -> Thirst Renal responsiveness to tonicity Adequate delivery of water and solutes to glomerulus of kidney ( Problem: Early reabsorption of water due to volume depletion or edematous states ) Water conservation mechanisms in kidney (Can be overridden by diuretics either in loop or in distal tubule. ADH in response to tonicity changes, i.e., Na, or in response to volume changes (Problems: SIADH and DI)

30. Diuretics Both Thiazides and Loop diuretics block Na reabsorption and cause decrease in ECF, too. Loop cause greater loss of Na but equal water, but thiazides lose less water than Na and can cause hyponatremia .

31. Manifestations of Fluid, and Electrolyte Imbalances Imbalances of Intake and Output and Body Weight Changes in Mental Status Changes in Vital Signs Abnormal Tissue Hydration Abnormal Muscle Tone

32. Signs and Symptoms of Dehydration *Poor skin turgor (tenting of the skin of the back of the hand is common in normal geriatric patients b/c of age-related skin changes A recent history of poor oral intake and/or a documented weight loss are probably better warning signs of dehydration in geriatric residents. Difficulty swallowing Clumsiness Shriveled skin Sunken eyes Visual disturbances Painful urination Numb skin Muscle spasm Delirium Headache Fatigue Loss of appetite Flushed skin Heat intolerance Light-headedness Dry mouth or eyes Burning sensation in stomach Dark urine with strong odor Advanced Dehydration Early Dehydration

34. Nursing Interventions Health Promotion Teaching depending upon setting Altered Function Oral fluid increase Oral fluid restriction Electrolyte replacement Diet or supplement IV therapy

35. Renal failure, chemoTx, enemas containing Malnourished, alcohol withdrawal, phosphate- binding antacids Muscle, RBC’s, CNs, w/ Calcium in bones and teeth 1.7-4.6 Phos Phosphate Maalox and Milk of Magnesia in patients with renal failure Diarrhea, vomiting, NG Suction, hyper aldosteronism Muscle, RBC’s and CNS, metabolism 1.5-2.5 Mg Magnesium Mult. Myeloma, thiazide diuretics, malignancies, Chronic renal failure, Vit D deficiency, pancreatiti,s, loop diuretics, diarrhea hyporparathyroidism Transmission of nerve impulses, cardiac contractions, bone, blood clotting 4.5-5.5 Ca Calcium Acidosis Renal disease K containing drugs K salt substitute GI Losses – diarrhea, vomiting, duretics, diaphoresis Major ICF cation; cellular and metabolic functions including cardiac rhythms 3.5-5.0 K Potassium High fever, heatstroke due to insensible water loss, diabetes insipidus GI Losses Diuretics, burns, wound drainage Maintains concentration of ECF 135-145 Na Sodium Hyper Causes Hypo Causes Function Normal Value Symbol Name Serum Electrolytes

36. Objective Data Neck Vein Distention Central Venous Pressure Pulmonary Artery Pressure Bowel Assessment Laboratory and Diagnostic Tests Urine Tests Blood Tests

37. Central Venous Pressure or Jugular Venous Distention

38. Assessment Subjective Data Normal Pattern Identification Risk Identification Dysfunction Identification Objective Data—Physical Assessment Intake and Output Body Weight Integumentary Assessment

39. plasma expander Isotonic (308 mOsm/L) 10% Dextran 40 in 0.9%NS closely resemble the electrolyte composition of normal blood serum and plasma; will need additional K; does not provide calories or free water; used to treat losses from lower GI tract and burns. Isotonic (273 mOsm/L) Lactated Ringer’s Solution provides free water (hypotonic) to the extracellular and intracellular spaces, as the dextrose is quickly metabolized; promotes renal elimination of solutes; treats hypernatremia; does not provide electrolytes; one liter is 170 calories Isotonic (252 mOsm/L) D5W - 5% Dextrose in water to treat fluid volume deficit; for daily maintenance of body fluids and nutrition; basically the same as NS, except provides 170 calories per liter Hypertonic (559 mOsm/L) D5NS - 5% Dextrose & 0.9NaCl to promote renal function and excretion; basically the same as .45NS except provides 170 calories per liter Hypertonic (406 mOsm/L) D5 1/2 NS - 5% Dextrose & 0.45NaCl assists with renal function; provides free water, Na and Cl.; replaces normal hypotonic daily fluid losses- assists with daily body fluid needs, but not with electrolyte replacement or provision of calories. Hypotonic (154 mOsm/L) 1/2 NS - 0.45%NaCl replaces NaCl deficit and restores/expands extracellular fluid volume; the only solution that may be administered with blood products --does not provide free water that causes hemolysis of red blood cells Isotonic (308mOsm/L) NS - 0.9% NaCl Usage and Limitations Osmolality Solution

40. Third Spacing: Loss of fluid into a space that cannot contribute to ICF/ECF equilibrium S&S: Urine output decreases Increased heart rate Decreased BP Decreased CVP Increased body weight Edema I & O imbalance Causes: Burns Ascites Peritonitis Bowel obstruction Massive bleeding into joint or body cavity

41. Factors Affecting Fluid, Electrolyte, and Acid-Base Balance Fluid and Food Intake Fluid and Electrolyte Output Stress Chronic Illnesses Surgery Pregnancy

42. Acid Base Balance Two systems work to maintain correct pH. Respiratory System by adjusting respirations. Metabolic system by adjusting serum HCO3

43. Acid Base Balance

44. Acidosis pH < 7.4 Increased paCO2 Decreased HCO3

45. Acid…………………Base High CO2 Low HCO3 Low CO2 High HCO3 pCO2 = 35-45 HCO3 = 22-28

46. Respiratory Acidosis Hypoventilation for any reason COPD Paralysis of respiratory muscles Cardiac Arrest – Code

47. Metabolic Acidosis Starvation DKA Renal Failure Lactic Acidosis from heavy exercise Drugs – EtOH, ASA Diarrhea

48. Alkalosis pH > 7.4 Decreased CO2 Increased HC03

49. Respiratory Alkalosis Hyperventilation from any cause Pneumonia Too high ventilator settings

50. Metabolic Alkalosis Excessive vomiting Gastric suctioning Hypokalemia OR Hypercalcemia Excess aldosterone Drugs – Steroids, diuretics, NaHCO3

51. Easy Read of Blood Gases Check pH <7.4 = Acidosis; > 7.4 = alkalosis Which of the following parameters matches the pH? CO2 or HCO3? High C02 is acid; low CO2 is alkaline- respiratory High HCO3 is alkaline; low HCO3 is acid - metabolic Matching parameter + pH direction is diagnosis! If both parameters match, then it is a combined _____; if opposite parameter is abnormal, compensation is occurring.