Fluid And Electrolytes

1. Fluid And Electrolytes Nur 102 SpringSemester

2. Fluid and Electrolytes * The proportion of fluid is large * 60% of the adult’s wt is water. Functions of water: 1)- Medium for metabolic reactions within cells. 2)- Transport for nutrients, waste products & other substances. 3)- Lubrication. 4)- Shock absorber. 5)- regulating & maintaining body temp.

3. * Factors affect total body water: 1)- Age: The proportion of body water decreases with aging. * Infants have the highest proportion ( 70-80%) of wt. 2)- Body fat tissues: fat tissues are free of water. * Lean tissues contain significant amount of water. * Water makes up lean body wt >obese persons. 3)- Sex : women have more body fat than men , so they have less water. *Distribution of body fluids: 1)- ICF: fluid within the cells. * Composes 2/3 of total body fluid in adults. * Functions of ICF: - Vital for normal cell function: it contains solutes ( O2, electrolytes, & glucose). - It provides a medium for metabolic processes.

4. 2)- ECF: outside cells & composes 1/3 of total body fluid . * ECF composed of : A)- Intravascular fluid: or plasma found within vascular system, 20% of ECF. B)- Interstitial fluid : surrounds cells ( lymph). compose 3\4 0f ECF, transport waste from cells, 75% of ECF C)- Trancellular fluid: includes : CSF, pleural, peritoneal , & synovial fluids, intraocular and biliary. * Functions of ECF: Transport system carries nutrients to & waste products from the cells. * e.g. Plasma carries O2 from lungs & glucose from GIT →capillaries of vascular system →into interstitial spaces →into cells ( via cellular membrane). The opposite route for waste products CO2 from cells → lungs & metabolic acid wastes →kidneys

5. * Composition of Body Fluids : Many salts dissociate in water : break up into charged ions: - Cations: +ve charged ions( e.g. Na + , K+, Ca +2. MG+2). -Anions : - ve charged ions (e.g. Cl-, HCO3 , SO4, HPO4).

6. * Movement of body fluids: * Selective permeability of the cellular membrane ( small particles(O2, ions, CO2 ) can easily cross the membrane while large molecules can not ( proteins & glucose) pass. 1)- Osmosis: movement of H2O across cell membrane from the less concentrated solution to the more concentrated solution. Solute: substance dissolved in liquid Solvent: dissolve a solute e.g in body water is the solvent while electrolyte,O2, CO2 is solute

7. * Osmolality: concentration of solutes in the body fluids ( mOsm/Kg) or tonicity ( isotonic, hypotonic, hypertonic).. - Na is the main determinant of osmolality in ECF while K, glucose & urea are basic for ICF. * Osmotic pressure: power of solution to draw water across semipermiable membrane. * Colloid osmotic pressure : ( Oncotic): osmotic pressure created by proteins pulling water from interstitial space into the vascular.( important in maintaining vascular volume). Types of solution: Isotonic Hypotonic Hypertonic

9. 2)- Diffusion: movement of molecules from solution of higher concentration to solution of lower concentration * The rate of diffusion is affected by ( size , concentration, & temperature of the solution ).. 3)- Filtration: Fluid & solutes move together a cross a membrane from one compartment (higher pressure) to another (lower pressure) ( e.g. movement of fluid & nutrients from the capillaries of the arteries to the interstitial fluids around the cells).

10. Diffusion

11. * Filtration pressure : pressure that results in the movement of fluid & substances out of the compartment. * Hydrostatic pressure: pressure exerted by a fluid within a closed system on the walls of the container ( e.g. force exerted by the blood against arteries). 4)- Active transport: energy is needed : substance combines with a carrier on the outside surface of the cell membrane & they move to the inside surface of the membrane. Fluid moves from area of less concentration to the area of high concentration (as Na- k pump)

12. Active Transport

13. * Regulation of body fluids: normally fluid intake & loss are balanced. 1)- Fluid intake: the average adult drinks ( 1500 ml/day ) but needs 2500 ml ( additional 1000ml). - Thirst mechanism is the primary regulator of intake. - Thirst center in the brain triggered by (osmotic pressure, vascular volume, & Angiotesein II( released as a result of ↓blood flow to kidneys). Runner example : ↑concentration of solutes & ↑osmotic pressure stimulates thirst & desire to drink water.

14. Additional 1000ml of fluid taken from food 90% from fresh vegetables 85% from fresh fruit 60% from lean meat 200 ml of water as a byproduct of food metabolism

15. 2)- Fluid output: 4 routs: A) Urine : ( major route of output). volume formed by the kidneys & exerted from the bladder * Average urine output: adult 1400-1500/24 hrs(30-50ml /hr). *↑intake →↑UO. * if loss by other routs increased ( urine decreased to maintain fluid volume).

16. B)- Insensible fluid loss: not noticeable & cannot be measured. - Lungs: 350-400 ml . - Skin: 350-400 ml. - Sweat: 100ml : fever & exercise increase loss via skin. C)- Feces: 100- 200 loss . Obligatory fluid loss : must be lost to maintain body function : feces , respiration & skin - 500 ml of fluid must be exerted by kidneys.

17. Homeostasis: regulation System involve in homeostasis are kidney, lung, cardiovascular, endocrine and GIT 1)- Kidneys: regulate fluid & electrolytes excretion , reabsorbing , & acid –base balance( regulating excreting & reabsorbing of H+ ion & HCO3+) . 2)- ADH: hypothalamus : regulate water excretion from the kidneys . - ↑osmolality → ↑ ADH production : increase permeability of collecting ducts to water →allows more water to be reabsorbed into blood.

18. As more water is reabsorbed →↓UO→ ↓serum osmolality because water dilutes body fluids . • ↓osmolality → ↓ADH→ ↑ UO.

19. 3)- Renin-Angiotensein – Aldesterone System: - if blood flow to kidneys ↓ → release of rennin. →converting of angiotesinonogen into angiotesein I →Angiotesein II by ACE →angiotesein II acts on nephrons & ↑Na & water retention& stimulate the release of Aldesterone from adrenal cortex → retention of Na & water in distal nephrons and excretion of K. -This system helps to restore blood volume. 4)- ANF: (Atrial Natriuretic Factor):released from cells in the atria of heart in response to excess blood volume & stretching of the atrial walls.. -Acts as diuretics to loose water & Na. - Inhibit thirst lead to decrease fluid intake

20. * Regulating Electrolytes : General functions: 1)- Maintain fluid balance . 2)- contribute to Acid-base regulation. 3)- Facilitating enzyme reactions. 4)- transmitting Neuromuscular reactions. Na: Most abundant cation in ECF & major contribute to S. osmolality Control and regulate water balance to maintain ECF volume NR 135 – 145 mEq\l if < 135 ( hyponatremia), if > 145 (hypernatremia) K: Major cation in ICF Maintain ECF and ICF balance Vital electrolyte to skeletal, cardiac and smooth muscle activity

21. Also maintain acid – base balance NR 3.5 – 5 mEq\l, if <3.5 (hypokalemia) if >5 (hyperkalemia) Ca: Majority is in skeletal system Vital in regulating muscle contraction and relaxation, neuromuscular & cardiac function Regulated by PTH, calcitonin & calcitirol NR 8.5 – 10.5 mg\dl, if <8.5 (hypocalcemia) if > 10.5 (hypercalcemia)

22. * Regulation of Acid-Base Balance: -Normal arterial pH (7.35-7.45). 1)- Buffers: preventing excessive changes in pH by removing or releasing H+ . A)- Major buffer : HCO3 & H2CO3. -PH ↓→acidosis. -PH ↑ →Alkalosis. B)- Proteins, Hb, & phosphate. 2)- Respiratory regulation : by eliminating or retaining CO2 ( potential acid ).: CO2+H2O↔ H2CO3 - Lungs can regulate level of CO2 by altering rate & depth of respiration. - Regulate CO2 & HCO3. 3) Renal regulation : slower to respond to changes (hrs-days _) to compensate imbalance - Regulate H+ & HCO3 reabsorption & excretion in response to alkalosis & acidosis. - Normal HCO3 (22-26 mEq/L)..

23. * Factors affecting body fluid , electrolytes & acid-base balance: 1) Age:Infants: -High fluid loss ( high MR). - Immature kidneys : less able to conserve water. - High insensible loss by rapid respiration. * In elderly - High risk for dehydration due to : - impaired thirst response. - Nephrons become less able to conserve water in response to ADH ( normal or elevated) - ↑ANF : loss of ability to conserve water. - Presence of combining diseases : heart diseases, impaired renal function, & multiple drug regimen. 2)- Gender & body size. 3)- Environmental temperature: sweating.( loss of H2O, & salts).

24. 4)- Lifestyle: A)- Diet: anorexia nervosa or bulimia ( induced vomiting, use diuretics & laxatives) ( eating disorder) leads to malnutrition & fluid depletion . B)- Regular weight bearing exercises : +ve effect on Ca balance & prevent osteoporosis. C)- Stress: ↑: - Cellular metabolism - Blood glucose levels. - Catecholamine. ADH : increase blood volume. D)- Other factors: - alcohol: cause electrolyte depletion, & acidosis due to break down of fat tissues. - Illness: decrease blood flow to kidneys due to impaired cardiac functions, DM , COPD ( acid base balance). - Trauma: & burns: loss of fluid & electrolytes from damaged cells - Medications: diuretics or corticosteroids

25. Fluid Imbalances • 2 basic type: isotonic & osmolar • Isotonic imbalance: water & electrolyte are lost or gained in equal proportion, osmolarity remain constant • Osmolar imbalance: when water is lost or gained alone, osmolarity altered • 4 categories: • Isotonic loss (FVD, or hypovolemia) • Isotonic gain (FVE, or hypervolemia) • Hyperosmolar loss ( dehydration) • Hypo- osmolar gain ( over hydration, or water intoxication)

26. FVD • Occur when body loss both water and electrolyte from ECF in same proportion . • Causes: • Abnormal loss through skin, GIT, & kidney (excessive sweating, V&D, polyuria, fever NGT suction) • Decrease intake of fluid (anorexia, N, inability to take fluid, impaired swallowing) • Bleeding • Shift of fluid into third space.

27. FVE • Occur when body gain water and electrolyte in same proportion to ECF. • Causes: • Excess intake of NaCl • Excess intake of Na containing IVF • Impaired fluid balance regulation related to disease process as in ( HF, RF, liver cirrhosis)

28. Edema occur in FVE, it is an increase fluid accumulation in interstitial fluid Pitting edema: small depression or indentation left after applying pressure to swollen area, mainly over bony prominence, disappear within 5sec

30. Dehydration • Hyperosmolar imbalance • Occur when water alone is lost from the body • Occur in: • Older adult • In hyperventilation, or prolonged fever • In DKA • Enteral feeding without sufficient water intake

31. Overhydration • Hypo-osmolar imbalance (water intoxication) • Gain of water in excess of electrolyte

32. Assessment 1)- Ng Hx: - A)- Identify pts who are at risk of fluid ,electrolyte, & acid-base imbalance (e.g. COPD, cardiac diseases, renal disease, gastroenteritis...(See Box: risk , factors ). B)- Obtain data about food & fluid intake . C)- Data about Fluid output. D)- presence of S&S suggestive of altered fluid & electrolytes 2)- P/E: includes: ( SEE Table: Focused P/E Assessment for fluid & Electrolytes). A)- Skin( e.g. color, temp, turgor). B)- Oral cavity & mucous membranes: (color, moisture). C)- Eyes: Firmness. D)- Cardiovascular : H.R , B.P, pulses, …. E)- Respiratory system: lung sounds , R.R. F)- Neurological : LOC, reflexes, motor functions.

33. 3)- Clinical measurements: A)- Daily wt: significant changes wt over a short period ( days to 1-2 weeks) indicates acute fluid changes. - Each Kg loss = 1L fluid. - Wt reflects total body fluid rather than any compartment. * Moderate to severe fluid volume deficit or excess : wt loss or gain of 5-8% of total body weight. * Measurement of wt should be reliable.

34. B) V/S: - ↑Temp: in dehydration, or increased fluid loss. - Tachycardia is an early sign of hypovolemia. ↓Pulse volume in FVD & ↑FVE. - Irregular pulse in electrolytes imbalances. - Changes in R.R & depth affect acid-base balance. - BP: indicates blood volume change (e.g.↓ in hypovolemia & ↑in FVE. - Orthostatic hypotension. C)- Fluid intake & output: 24 hrs measurement of I& O. * Measurement of fluid intake: 1)- Oral fluids: all types of fluids drunk by the pt ( water with medication…). 2)- Ice chips: one half their volume. 3)- Foods that tend to be liquid in the room temp( jello). 4)- Tube feeding : including water for rinsing. 5) - Parenteral fluids : IVF. 6)- IV medication: some are diluted in large amounts of solutions (50-100ml). 7)- Catheter or tube irrigates .

35. * Measurement of output: 1)- Urine output : following each voiding use container to measure. 2)- Vomitus & liquid feces. 3)- Tube drainage: : gastric drainage. 4)- Wound drainage & draining fistula: * I&O are recorded & totaled at the end of the shift (8-12 hrs).

36. D)- Laboratory tests: 1)- Serum electrolytes : Na, K, urea. 2)- CBC: e.g. HTC ↑ in sever dehydration, and ↓ in sever Overhydration. 3)-Serum Osmolality: measure of solute concentration of the blood.( normal is 280-300 mOsm/Kg),↑ with FVD and ↓ with FVE. - Determined by Na, glucose & urea ( BUN) 4)- Urine Osmolality : solute concentration of urine( urea, Createnine, & uric acid). - Normal ( 500-800 mOsm/Kg), ↑ with FVD and ↓ with FVE. 5)- Urine pH : by analysis or dipstick on urine specimen, indicate the kidney regulation of acid- base imbalances . 6)- Urine specific gravity: indicator of urine concentration ( 1.005-1.030), increase solute concentration in urine ↑ USG.

37. 7)- ABGs: includes: - pH 7.35- 7.45 - Pao2. 80-100 - Paco2. 35-45 -HCO3. 22-26 - O2 saturation 95-98 Base excess. +2 or -2

38. DX - Fluid Volume Deficit. - Fluid Volume Excess. - Risk for Fluid Volume Imbalance . - Risk for Fluid Volume Deficit. - Impaired Gas Exchange. - Altered Oral Mucous Membrane R\T FVD. -Impaired Skin Integrity RT dehydration /edema. • Decreased Cardiac Output RT cardiac dysrhythmias secondary to electrolytes imbalance ( K). • ineffective Tissue Perfusion.Rt decrease CO secondary to FVD. - Activity Intolerance RT hypervolemia. - Risk for injury R\t Ca shift out of bones into ECF.

39. Planning 1)- Maintain or restore normal fluid balance. 2)- Maintain or restore normal balance of electrolytes in IC or EC compartment. -3)- Maintain or restore pulmonary ventilation & oxygenation. 4)- Prevent associated risks ( tissue breakdown, decreased CO, neurological signs).

40. Implementation 1)- Promoting wellness: people must know that it is important to drink adequate fluids & consume a balanced diet. 2)- Enteral fluid & electrolyte replacement: A)- Fluid intake modifications : - Increase fluids: in pts with risk or actual FVD. - Restrict fluids: Pts who have fluid retention which results from many diseases( HF, RF, SIADH).

41. B)- Dietary changes: - e.g. pts who receive K depleting diuretics : must receive K ( supplements or by food ( banana, orange , leafy greens). C)- Oral electrolyte supplements. 3)- Parenteral fluid & electrolyte replacement: IVF ( isotonic, hypertonic, hypotonic). - Regulating rate of fluid flow: - Total infusion volume Χ drop factor divided on Total time of infusion in minutes. 4)- Blood Transfusion of blood