FLUIDS AND ELECTROLYTES ELECTROLYTES Introduction To maintain good health, a balance of fluids and electrolytes, acids and bases must be normally regulated for metabolic processes to be in working state. A cell, together with its environment in any part of the body, is primarily composed of FLUID. Thus fluid and electrolyte balance must be maintained to promote normal function. Potential and actual problems of fluid and electrolytes happen in all health care settings, in every disorder and with a variety of changes that affect homeostasis. The nurse therefore needs to FULLY understand the physiology and pathophysiology of fluid and electrolyte alterations so as to identify or anticipate and intervene appropriately. appropriately. Fluids - a solution of solvent and solute Solvent - a liquid substance where particles can be dissolved Solute - a substance, either dissolved or suspended in a solution Solution a homogeneous mixture of 2 or more substances of dissimilar molecular structure usually applied to solids in liquids but applies equally to g asses in liquids Body Fluids A. Func Functi tion on 1. Transpor Transporter ter of nutrie nutrients nts , wastes wastes,, hormones, hormones, proteins proteins and etc 2. Medium Medium or or milieu milieu for for metab metaboli olicc proces processes ses 3. Body Body temp temper eratu ature re regul regulat atio ion n 4. Lubric Lubricant ant of of muscu musculos loskel keleta etall joint jointss 5. Insu Insula lato torr and sho shock ck abso absorb rber er B. Body Body Fluid Fluid Compa Compart rtmen ments ts C. Body Comp Compart artmen mentt Volum Volumes es neonates reach adult values by 2 yrs and are about half-way ha lf-way by 3 months average values ~ 70 ml/100g of lean body mass percentage of water varies with tissue type, A. lean lean tiss tissues ues ~ 60-80 60-80% % B. bone bone ~ 20-2 20-25% 5% C. fat fat ~ 10-1 10-15% 5% D. Tonicity onicity of of Body Body Fluid Fluidss Tonicity refers to the concentration c oncentration of particles in a solution The normal tonicity or osmolarity of body fluids is 250-300 mOsm/L 1.Isotonic Same as plasma 2.Hypotonic have a lesser or lowers solute concentration than plasma 3.Hypertonic higher or greater concentration of solutes Osmole the weight in grams of a substance producing an osmotic pressure of 22.4 atm. when dissolved in 1.0 litre of solution (gram molecular weight) / (no. of freely moving pa rticles per molecule) Osmolality the number of osmoles of solute per kilogram of solvent Osmolarity the number of osmoles of solute per litre of solution Mole that number of molecules contained in 0.012 kg of C12, C12 , or, Avogadro's number num ber the molecular weight of a substance in grams = Avogadro's = 6.023 x 1023 Molality the number of moles of solute per kilogram of solvent Molarity is the number of moles of solute per litre of solution THE Normal DYNAMICS OF BODY FLUIDS The methods by which electrolytes and other solutes move across biologic membranes are Osmosis, Diffusion, Filtration and Active Transport. Osmosis, diffusion and filtration are passive processes, while Active transport is an active process. 1. OSMOSIS This is the movement of water/liqu water/liquid/so id/solvent lvent across a semi-permea semi-permeable ble membrane from a lesser lesser concentration to a higher concentration Osmotic pressure is the power of a solution to draw water across a semi-permeable membrane
Colloid osmotic pressure (also called oncotic pressure) is the osmotic pull exerted by plasma proteins 2. DIFFUSION “Brownian movement” or “downhill movement” The movement of particles/solutes/molecules from an area of higher concentration to an area of a lower concentration This process is affected by: a. The size of the molecules- larger size moves slower than smaller size b. The concentration of solution- wide difference difference in in concentration has a faster rate of diffusion c. The temperature- increase in in temperature causes increase increase rate of diffusion diffusion Facilitated Diffusion is a type of diffusion, which uses a carrier, but no energy is expended. One example is fructose and amino acid transport process in the intestinal cells. This type of diffusion is saturable. 3. FIL FILTRA TRATION TION of BOTH solut solutee and solvent solvent together across a membrane membrane from an area of This is the movement of BOTH higher pressure to an area of lower pressure Hydrostatic pressure is the pressure exerted by the fluids within the closed system in the walls of the container 4. ACTI ACTIVE VE TRAN TRANSP SPOR ORT T Process where substances/solutes move from an area of lower concentration to an area of higher concentration with utilization of ENERGY It is called an “uphill movement” Usually, Usually, a carrier c arrier is required. An enzyme is utilized also. Types of Active Transport: a. Prim Primar aril ily y Acti Active ve Tran Transp spor ortt Energy is obtained directly from the breakdown of ATP ATP One example is the Sodium-Potassium pump b. Seconda Secondary ry Active Active Trans Transpor portt Energy Energy is derived secondarily from stored energy in the form of ionic concentratio concentration n difference difference between two sides of the membrane. One example is the Glucose-Sodium co-transport; also the Sodium-Calcium counter-transport THE REGULATION OF BODY FLUID BALANCE To maintain homeostasis, many body systems interact to ensure a balance of fluid intake and output. A balance of body fluids normally occurs when the fluid output is balanced by the fluid input Overview of Fluid Regulation by the Body Systems
A. Systemi Systemicc Regulato Regulators rs of Body Body Fluids Fluids 1. Renal Regulation (RAS) This system regulates sodium and water balance in the ECF The formation of urine is the main mechanism Substa Substance nce releas released ed to regula regulate te water water balanc balancee is RENIN. RENIN. Renin Renin activa activates tes Angioten Angiotensin sinogen ogen to Angiotensin-I, A-I is enzymatically converted to Angiotensin-II ( a powerful vasoconstrictor)
2.
Endocrine Regulation mechanism, controlled by the thirst center in the The primary regulator of water intake is the thirst mechanism, hypothalamus (anterolateral wall of the third ventricle) Anti-diuretic hormone (ADH) is synthesized by the hypothalamus and acts on the collecting ducts of the nephron ADH increases rate of water reabsorption The adrenal gland helps control F&E through the secretion of ALOSTERONE- a hormone that promotes sodium retention and water retention in the distal nephron ATRIAL NATRIURETIC factor (ANF) is released by the atrial cells of the heart in response to excess blood volume and increased wall stretching. ANF promotes sodium excretion and inhibits thirst mechanism 3. Gastro-intestinal regulation The GIT digests food and absorbs water The hormonal and enzymatic activities involved in digestion, combined with the passive and active transport of electrolyte, water and solutions, maintain the fluid balance in the body. B. Flui Fluid d Inta Intake ke Healthy adult ingests fluid as part of the dietary intake. 90% of intake is from the ingested food and water 10% of intake results from the products of cellular metabolism Usual intake of adult is about 2, 500 ml per day The other sources of fluid intake are: IVF, IVF, TPN, Blood products, and colloids C. Flui Fluid d Ou Outp tput ut 2 , 500 ml per day, counterbalancing the input. The average fluid losses amounts to 2, The routes of fluid output are the following: SENSIBLE LOSS- Urine, feces or GI losses, sweat INSENSIBLE LOSS- though the skin and lungs as water vapo r URINE- is an ultra-filtrate of blood. The normal output is 1,500 ml/day or 30-50 ml per hour or 0.51 ml per kilogram per hour ho ur.. Urine is formed from the filtration process in the neph ron FECAL loss- usually amounts to about 200 ml in the stool Insensible loss- occurs in the skin and lungs, which are not noticeable and cannot be accurately measured. Water Water vapor goes out of the lungs and skin. Water Metabolism Daily Balance: turnover ~ 2500 ml a. Intake • drink ~ 1500 ml • food ~ 700 ml • metabolism ~ 300 ml b. Losses • urine ~ 1500 ml • skin ~ 500 ml • insensible losses ~ 400 ml • sweat ~ 100 ml • lungs ~ 400 ml • faeces ~ 100 ml Minimum daily intake ~ 500 ml with a "normal" diet Minimum losses ~ 1500 ml/d Losses are increased with; a. increased ambient T b. hyperthermia ~ 13% per °C c. decreased relative humidity d. increased minute ventilation e. increased MRO2 FLUID IMBALANCES Fluid Volume Deficit or Hypovolemia Definition: This is the loss of extra cellular fluid volume that exceeds the intake of fluid. The loss of water and electrolyte is in equal proportion. It can be called in various terms- vascular, cellular or intracellular dehydration. But the preferred term is hypovolemia. Dehydration Dehydration refers to loss of WATER alone, with increased increased solutes solutes concentratio concentration n and sodium concentration Pathophysiology of Fluid Volume Volume Deficit Etiologic conditions include: 1. Vomiting 2. Diarrhea
3. Prol Prolong onged ed GI GI suc sucti tioni oning ng 4. Incr Increa ease sed d swea sweati ting ng 5. Inabil Inability ity to gain gain access access to to fluid fluidss 6. Inad Inadequ equat atee flu fluid id inta intake ke 7. Mass Massiv ivee thi third rd spac spacin ing g Risk factors are the following: 1. Diab Diabet etes es Ins Insip ipid idus us 2. Adre Adrena nall ins insuf uffi fici cienc ency y 3. Osmo Osmoti ticc diu diure resi siss 4. Hemo emorrhage 5 . Co m a 6. Third-spaci Third-spacing ng condition conditionss like like ascites, ascites, pancrea pancreatitis titis and burns burns PATHOPHYSIOLOGY: Factors inadequate fluids in the body decreased blood volume decreased cellular hydration cellular shrinkage weight loss, decreased turgor, oliguria, hypotension, weak pulse, etc. THE NURSING PROCESS IN FLUID VOLUME DEFICIT Assessment: 1. Phys Physic ical al exam examin inat atio ion n • Weight loss, tented skin turgor, dry mucus membrane • Hypotension • Tachycardia • Cool skin, acute weight loss • Flat neck veins • Decreased CVP 2. Su Subj bjec ecti tive ve cues cues • Thirst • Nausea, anorexia • Muscle weakness and cramps • Change in mental state 3. Labo Labora rato tory ry fin findi ding ngss a. Elevated Elevated BUN due to depletion depletion of fluids fluids or decreas decreased ed renal renal perfusio perfusion n b. b. Hemo Hemoco conc ncen entr trat atio ion n c. Possible Possible Electroly Electrolyte te imbalances: imbalances: Hypokalemi Hypokalemia, a, Hyperkalemia Hyperkalemia,, Hyponatremia, Hyponatremia, hypernatr hypernatremia emia d. Urine specifi specificc gravity gravity is increased increased (concentr (concentrated ated urine) urine) above above 1.020 4. NURSING DIAGNOSIS - Fluid Volume deficit bo dy fluids 5. PLANNING - To restore body 6. IMPL IMPLEM EMEN ENT TATION TION ASSIST IN MEDICAL INTERVENTION • Provide intravenous fluid as ordered • Provide fluid challenge test as ordered 7. NURS NURSIN ING G MANA MANAGE GEME MENT NT 1. Assess the ongoing status of the patient by doing an acc urate input and output monitoring 2. Monitor daily weights. Approximate weight loss 1 kilogram = 1liter! 3. Monitor Vital signs, skin and tongue turgor, urinary concentration, mental function and peripheral circulation 4. Prevent Fluid Volume Deficit from occurring by identifying risk patients and implement fluid replacement therapy as needed promptly 1. Correct Correct fluid Volume Volume Deficit Deficit by offering offering fluids orally orally if tolerated, tolerated, anti-emeti anti-emetics cs if with vomiting, vomiting, and foods with adequate electrolytes 2. Main Mainta tain in ski skin n inte integr grit ity y 3. Prov Provid idee freq frequen uentt oral oral car caree 4. Teach patient patient to change change position position slowly slowly to avoid avoid sudden sudden postural postural hypotensio hypotension n FLUID VOLUME EXCESS: HYPERVOLEMIA o f water and sodium Refers to the isotonic expansion of the ECF caused by the abnormal retention of There There is exce excess ssiv ivee rete retent ntio ion n of wate waterr and and elect electro roly lyte tess in equal equal propo proport rtio ion. n. Seru Serum m sodi sodium um concentration remains NORMAL Pathophysiology of Fluid Volume Volume Excess a. Etiolo Etiologic gic condi conditio tions ns and and Risks Risks fact factors ors • Congestive heart failure
• • • • • • •
Renal failure Excessive fluid intake Impaired ability to excrete fluid as in renal disease Cirrhosis of the liver Consumption of excessive table salts Administration of excessive IVF Abnormal fluid retention
b. b. PATHOP THOPHY HYSI SIOL OLOG OGY Y • Excessive fluid • expansion of blood volume • edema, increased neck vein distention, tachycardia, hypertension. The Nursing Process in Fluid Volume Excess ASSESSMENT Physical Examination 1. Incr Increas eased ed weig weight ht gain gain 2. Incr Increas eased ed urin urinee out outpu putt 3. Mois Moistt crack crackle less in the the lun lungs gs 4. Incr Increa eassed CVP 5. Dist Disten ende ded d neck neck vein veinss 6. Wheezing 7. Depe Depend nden entt edem edemaa Subjective cue/s 1. Shor Shortn tnes esss of bre breat ath h 2. Chang Changee in in ment mental al stat statee Laboratory findings 1. BUN and and Creatini Creatinine ne levels levels are LOW LOW because because of dilution dilution 2. Urine sodium and osmolali osmolality ty decrease decreased d (urine (urine becomes becomes diluted) diluted) 3. CXR may show show pulmo pulmonary nary congest congestion ion NURSING DIAGNOSIS Fluid Volume excess o IMPLEMENTATION ASSIST IN MEDICAL INTERVENTION • Administer diuretics as prescribed • Assist in hemodialysis • Provide dietary restriction of sodium and water NURSING MANAGEMENT 1. Cont Contin inua uall lly y asse assess ss the the pati patient ent’’s condi conditi tion on by meas measur urin ing g inta intake ke and outp output ut,, dail daily y weig weight ht monitoring, edema assessment and breath sounds 2. Prevent Prevent Fluid Volume Volume Excess Excess by adhering adhering to diet prescri prescription ption of low saltsalt- foods. foods. 3. Detect Detect and Control Control Fluid Volum Volumee Excess Excess by closel closely y monito monitorin ring g IVF therapy therapy,, admini administe sterin ring g medications, providing rest periods, placing in semi-fowler’s position for lung expansion and providing frequent skin care for the edema 4. Teach patient patient about edema, ascites ascites,, and fluid therapy therapy.. Advise Advise elevat elevation ion of the extremit extremities ies,, restriction of fluids, necessity of paracentesis, dialysis and diuretic therapy. 5. Instruct Instruct patient patient to avoid over-the-c over-the-counter ounter medicati medications ons without without first first checking with with the health care provider because they may contain sodium ELECTROLYTES Electrolytes are charged ions capable of conducting electricity and are solutes found in all body compartments. 1. Sources of electrolytes Foods and ingested fluids, medications; IVF and TPN solutions 2. Functions of Electrolytes Maintains fluid balance Regulates acid-base balance Needed for enzymatic secretion and activation Needed for proper metabolism and effective processes of muscular contraction, nerve transmission 3. Types of Electrolytes CATIONSCATIONS- positively charged ions; examples are sodium, potassium, calcium ANIONS- negatively charged ions; examples are chloride and phosphates] The major ICF cation is potassium (K+); the major ICF anion is Phosphates The major ECF cation is Sodium (Na+); the major ECF anion is Chloride (Cl-) DYNAMICS OF ELECTROLYTE ELECTROLYTE BALANCE 1. Electrolyte Distribution
ECF and ICF vary in their electrolyte distribution and concentration ICF has K+, PO4-, proteins, Mg+, Ca++ and SO4ECF has Na+, Cl-, HCO3-
2. Electrolyte Excretion These electrolytes are excessively eliminated by abnormal fluid losses Routes can be thru urine, feces, vomiting, surgical drainage, wound drainage and skin excretion 3. Regulation of Electrolytes a) Renal Regulation occurs by the process of glomerular filtration, tubular reabsorption and tubular secretion b) Endocrine Regulation hormones play a role in this type of regulation: Aldosterone- promotes Na retention and K excretion ANF- promotes Na excretion PTH- promotes Ca retention and PO4 excretion Calcitonin- promotes Ca and PO4 excretion c) GIT Regulation electrolytes are absorbed and secreted some are excreted thru the stool THE CATIONS SODIUM The most abundant cation in the ECF Normal range in the blood is 135-145 mEq/L water. A loss or gain of sodium is usually accompanied by a loss or gain of water. Major contributor of the plasma Osmolality Sources: Diet, medications, IVF. The minimum daily requirement is 2 g rams Imbalances- Hyponatremia= <135 mEq/L; Hypernatremia= >145 mEq/L Functions: 1. Partic Participa ipates tes in the Na-K Na-K pump pump 2. Assist Assistss in main maintai tainin ning g blood blood volum volumee 3. Assists Assists in nerve nerve transmi transmission ssion and muscle muscle contraction contraction 4. Primary determinant of ECF concentration. body. 5. Controls water distribution throughout the body. 6. Primary regulator of ECF volume. 7. Sodi Sodium um also also func functi tions ons in the the esta establ blis ishm hmen entt of the the elect electro roch chem emic ical al stat statee neces necessa sary ry for for musc muscle le contraction and the transmission of nerve impulses. 8. Regulations: Regulations: skin, skin, GIT, GIT, GUT, GUT, Aldoster Aldosterone one increases increases Na retention retention in the kidney SODIUM DEFICIT: HYPONATREMIA Refers to a Sodium serum level of less than 135 mEq/L. This may result from excessive sodium loss or excessive water gain. Pathophysiology Etiologic Factors 1. Fluid Fluid loss such such as from Vomiting omiting and nasogastr nasogastric ic suctioning suctioning 2. Diarrhea 3. Sweating 4. Use Use of diur diuret etic icss 5. Fistula Other factors 1. Dilu Diluti tion onal al hypon hyponat atre remi miaa • Water intoxication, compulsive water drinking where sodium level is diluted with increased water intake 2. SIADH • Excessive secretion of ADH causing water retention and dilutional hyponatremia Hyponatremia hypotonicity of plasma water from the intravascular space will move out and go to the intracellular compartment with a higher concentration cell swelling ater is pulled pulled INTO INTO the cell cell becaus becausee of decreas decreased ed extrac extracell ellula ularr sodium sodium level level and increa increased sed Water intracellular concentration The Nursing Process in HYPONATREMIA ASSESSMENT Sodium Deficit (Hyponatremia) ♦Clinical Manifestations Clinical manifestations of hyponatremia depend on the cause, magnitude, and rapidity of onset.
Although nausea and abdominal cramping occur, most of the symptoms are neuropsychiatric and are probably related to the cellular swelling and cerebral edema associated with hyponatremia. As the extrac extracell ellular ular sodium sodium level level decrea decreases ses,, the cellul cellular ar fluid fluid becomes becomes relati relatively vely more more concentrated and ‘pulls” water into the cells. In general general,, those those patien patients ts having having acute acute decline decline in serum serum sodium sodium levels levels have more more severe severe symptoms and higher mortality rates than do those with more slowly developing h yponatremia. Features of hyponatremia associated with sodium loss and water gain include anorexia, muscle cramps, and a feeling of exhaustion. When the serum sodium level drops below 115 mEq/L (SI: 115 mmol/L), thee ff signs of increasing intracranial pressure occurs: lethargy o Confusion o muscular twitching o o focal weakness hemiparesis o o papilledema convulsions o In summary: Physical Examination 1. Alte Altere red d ment mental al stat status us 2. Vomiting 3. Lethargy 4. Muscle Muscle twitching twitching and and convulsions convulsions (if sodium sodium level level is is below 115 mEq/L) mEq/L) 5. Focal ocal weakn eaknes esss Subjective Cues 1. Nausea 2. Cramps 3. Anorexia 4. Headache Laboratory findings 1. Serum Serum sodi sodium um level level is is less less than than 135 135 mEq/L mEq/L 2. Decr Decreas eased ed seru serum m osmol osmolali ality ty 3. Urine specific specific gravity gravity is LOW LOW if caused by sodium sodium loss loss 4. In SIADH, SIADH, urine urine sodium sodium is is high and specifi specificc gravity gravity is is HIGH HIGH NURSING DIAGNOSIS Altered cerebral perfusion Fluid volume Excess IMPLEMENTATION ASSIST IN MEDICAL INTERVENTION Provide sodium replacement as ordered. Isotonic saline is usually ordered.. Infuse the solution very cautiously. The serum sodium must NOT be increased by greater than 12 mEq/L because of the danger of pontine osmotic demyelination Administer lithium and demeclocycline in SIADH Provide water restriction if with excess volume NURSING MANAGEMENT 1. Provide Provide continuous continuous assessmen assessmentt by doing an accurate accurate intake intake and output, output, daily weights, weights, mental mental status status examination, urinary sodium levels and GI manifestations. Maintain seizure precaution 2. Detect and and control Hyponat Hyponatremia remia by encouragi encouraging ng food intake intake with high high sodium content, content, monitor monitoring ing patients on lithium therapy therap y, monitoring input of fluids like IVF, parenteral medication and feedings. 3. Return Return the Sodium Sodium level to Normal Normal by restri restricti cting ng water intake intake if the primar primary y problem problem is water retention. Administer sodium to normovolemic patient and elevate the sodium slowly by using sodium chloride solution SODIUM EXCESS: HYPERNATREMIA HYPERNATREMIA Serum Sodium level is higher than 145 mEq/L There is a gain of sodium in excess of water or a loss of water in excess of sodium. Pathophysiology: Etiologic factors 1. Flui Fluid d depr depriv ivat atio ion n 2. Water loss loss from Watery Watery diarrhea diarrhea,, fever, fever, and hyperventila hyperventilation tion 3. Admini Administr strati ation on of hypert hypertoni onicc solutio solution n 4. Increa Increased sed insens insensibl iblee water water loss loss 5. Inadequate Inadequate water replacement, replacement, inability inability to swallo swallow w 6. Seawater Seawater ingesti ingestion on or excessive excessive oral oral ingestio ingestion n of salts salts Other factors 1. Diab Diabet etes es ins insip ipid idus us
2. Heat stroke oke 3. Near Near drow drowni ning ng in ocean ocean 4. Malf Malfun unct ctio ion n of dial dialys ysis is Increased sodium concentration hypertonic plasma o utside to the interstitial space water will move out form the cell outside CELLULAR SHRINKAGE then to the blood Water pulled from cells because of increased extracellular sodium level and decreased cellular fluid concentration The Nursing Process in HYPERNATREMIA A. Sodium Excess (Hypernatremia) Clinical Manifestations • primarily neurologic • Presumably the consequence of cellular dehydration. • Hypernatremia results in a relatively concentrated ECF, ECF, causing water to be pulled from the cells. • Clinically, Clinically, these changes chang es may be manifested man ifested by: o restlessness and weakness in moderate hypernatremia disorientation, delusions, and hallucinations in severe hypernatremia. o • Dehydration (hypernatremia) is often overlooked as the primary reason for behavioral changes in the elderly. • If hypernatremia is severe, permanent brain damage can occur (especially in children). Brain damage is apparently due to subarachnoid hemorrhages that result from brain contraction. A primary characteristic of hypernatremia is thirst . Thirst is so strong a defender of serum sodium levels in normal people that hypernatremia never occurs unless the person is unconscious or is denied access to water; unfortunately, ill people may have an impaired thirst mechanism. Other signs include dry, swollen tongue and sticky mucous membranes. A mild elevation in body temperature may occur, but on correction of the hypernatremia the body temperature should return to normal. ASSESSMENT Physical Examination 1. Restle Restless ssnes ness, s, elevate elevated d body temper temperatu ature re 2. Diso Disori rien enta tati tion on 3. Dry, Dry, swollen swollen tongue and and sticky mucous membran membrane, e, tented tented skin turgor turgor 4. Flush Flushed ed skin skin,, postur postural al hypot hypotens ension ion 5. Increa Increased sed musc muscle le tone tone and and deep deep reflex reflexes es 6. Periph Peripheral eral and pulmon pulmonary ary edema edema Subjective Cues 1. Delusi Delusions ons and halluci hallucinat nation ionss 2. Ext Extreme reme thi thirrst 3. Beha Behavi vior oral al cha chang nges es Laboratory findings 1. Serum Serum sodi sodium um level level exceeds exceeds 145 mEq/ mEq/L L 2. Serum Serum osmol osmolali ality ty excee exceeds ds 295 295 mOsm/k mOsm/kg g 3. Urine specific specific gravity gravity and osmolali osmolality ty INCREAS INCREASED ED or elevated elevated IMPLEMENTATION ASSIST IN THE MEDICAL INTERVENTION 1. Administer Administer hypoton hypotonic ic electroly electrolyte te solution solution slowly slowly as ordered ordered 2. Admini Administe sterr diuret diuretics ics as orde ordered red 3. Desmopressi Desmopressin n is prescribed prescribed for diabetes diabetes insipidus insipidus NURSING MANAGEMENT 1. Continu Continuous ously ly monitor monitor the patien patientt by assessi assessing ng abnorm abnormal al loses of water water,, noting noting for the thirst thirst and elevated body temperature and behavioral changes 2. Prevent Prevent hypernatremia hypernatremia by offerin offering g fluids regularly regularly and plan with with the physician physician alternative alternative routes routes if oral route is not possible. Ensure adequate water for patients with DI. Administer IVF therapy cautiously 3. Correct Correct the Hypernatremia Hypernatremia by monitoring monitoring the patient’ patient’ss response response to the IVF replacement. replacement. Administer Administer the hypotonic solution very slowly to prevent sudden cerebral edema. 4. Moni Monito torr serum serum sodi sodium um level level.. 5. Reposition Reposition client client regularly regularly,, keep side-rails side-rails up, the bed in low position position and the call bell/li bell/light ght within within reach. 6. Provid Providee teachi teaching ng to avoid over-the over-the counter counter medicatio medications ns without without consult consultati ation on as they may contain contain sodium POTASSIUM The most abundant cation in the ICF
Potassium is the major intracellular electrolyte; in fact, 98% of the body’s potassium is inside the cells. The remaining 2% is in the ECF; it is this 2% that is all-important in neuromuscular function. Potassium is constantly moving in and out of cells according to the body’s needs, under the influence of the sodium-potassium pump. Normal range in the blood is 3.5-5 mEq/L Normal renal function is necessary for maintenance of potassium balance, because 80-90% of the potassium is excreted daily from the body by way of the kidneys. The other less than 20% is lost through the bowel and sweat glands. Major electrolyte maintaining ICF balance Sources- Diet, vegetables, fruits, fruits, IVF, IVF, medications Functions: 1. Main Mainta tain inss ICF ICF Osmo Osmola lali lity ty 2. Important Important for for nerve nerve conduction conduction and muscle muscle contraction contraction 3. Main Mainta tain inss acidacid-ba base se bala balance nce 4. Needed for for metabolis metabolism m of carbohy carbohydrates drates,, fats and proteins proteins 5. Potassium Potassium influenc influences es both skeleta skeletall and cardiac cardiac muscle muscle activity activity.. a. For example, example, alterations alterations in in its concentratio concentration n change myocardial myocardial irrita irritabilit bility y and rhythm. rhythm. Regulations: renal secretion and excretion, Aldosterone promotes renal excretion acidosis promotes K exchange for hydrogen Imbalances: Hypokalemia= <3.5 mEq/L Hyperkalemia=> 5.0 mEq/L
POTASSIUM POTASSIUM DEFICIT: HYPOKALEMIA Condition when the serum concentration concen tration of potassium is less than 3.5 mEq/L Pathophysiology Etiology 1. Gastro-inte Gastro-intestin stinal al loss of potassium potassium such as diarrhea diarrhea and fistul fistulaa 2. Vomitin omiting g and gastr gastric ic sucti suctioni oning ng 3. Meta Metabol bolic ic alkal alkalos osis is 4. Diaphor Diaphoresi esiss and and rena renall disor disorder derss 5. Ileostomy Other factor/s 1. Hyper Hyperal aldos doster teron onis ism m 2. Hear Heartt fai faillure ure 3. Neph Nephro roti ticc synd syndro rome me 4. Use of pota potassi ssiumum-los losing ing diur diureti etics cs 5. Insu Insuli lin n ther therap apy y 6. Starv arvati ation 7. Alcoh Alcohol olic icss and elde elderl rly y • Decreased potassium in the body impaired nerve excitation and transmission signs/symptoms such as weakness, cardiac dysrhythmias d ysrhythmias etc.. The Nursing Process in Hypokalemia Potassium Deficit (Hypokalemia) Clinical Manifestations Potassium deficiency can result in widespread derangements in physiologic functions and especially nerve conduction. Most important, severe hypokalemia can result in death through cardiac or respiratory arrest. Clinical signs rarely develop before the serum potassium level has fallen below 3 mEq/L (51: 3 mmol/L) unless the rate of fall has been rapid. Manifestati Manifestations ons of hypokalemia hypokalemia include fatigue, fatigue, anorexia, anorexia, nausea, nausea, vomiting, vomiting, muscle muscle weakness, weakness, decreased bowel motility, paresthesias, dysrhythmias, and increased sensitivity to digitalis. If prolonged, hypokalemia can lead to impaired renal concentrating ability, causing dilute urine, polyuria, nocturia, and polydipsia ASSESSMENT Physical examination 1. Musc Muscle le weak weakne ness ss 2. Decreased Decreased bowel motility motility and abdominal abdominal disten distention tion 3. Pares aresth thes esia iass 4. Dysr Dysrhy hytthmi hmias 5. Increa Increased sed sens sensiti itivit vity y to digi digital talis is Subjective cues 1. Naus Nausea ea , anor anorexi exiaa and vom vomit itin ing g 2. Fati Fatigue gue,, mus muscle cless cra cramp mpss 3. Exces Excessi sive ve thir thirst st,, if sever severee
Laboratory findings 1. Serum Serum potas potassiu sium m is less less than than 3.5 mEq/ mEq/L L 2. ECG: FLA FLAT “T” waves, waves, or inverted inverted T waves, depress depressed ed ST segment segment and presence presence of the “U” wave and prolonged PR interval. 3. Meta Metabol bolic ic alkal alkalos osis is
IMPLEMENTATION ASSIST IN THE MEDICAL INTERVENTION INTERVENTION 1. Provid Providee oral or IV IV replac replaceme ement nt of potass potassium ium 2. Infuse Infuse parenteral parenteral potassium potassium supplement. supplement. Always Always dilute the K in the IVF IVF solution solution and administer administer with a pump. IVF with potassium should be given no faster than 10-20-mEq/ hour! 3. NEVER NEVER admi adminis nister ter K by IV bolus bolus or or IM NURSING MANAGEMENT 1. Continu Continuous ously ly monitor monitor the patient patient by assessin assessing g the cardiac cardiac status status,, ECG monitori monitoring, ng, and digita digitalis lis precaution 2. Prevent Prevent hypokal hypokalemi emiaa by encourag encouraging ing the patient patient to eat potassiu potassium m rich foods like orange orange juice, juice, bananas, cantaloupe, peaches, potatoes, dates and apricots. 3. Correct Correct hypokalemia hypokalemia by administerin administering g prescribed prescribed IV potassium potassium replacement. replacement. The The nurse must ensure ensure that the kidney is functioning properly! 4. Administer Administer IV potassiu potassium m no faster than 20 mEq/hour mEq/hour and hook the patient patient on a cardiac monitor monitor. To To EMPHASIZE: Potassium should NEVER be given IV bolus or IM!! 5. A concentr concentration ation greater greater than than 60 mEq/L mEq/L is not not advisable advisable for peripheral peripheral veins. veins. POTASSIUM POTASSIUM EXCESS: HYPERKALEMIA Serum potassium greater than 5.5 mEq/L Pathophysiology Etiologic factors 1. Iatrog Iatrogeni enic, c, excess excessive ive intak intakee of potass potassium ium 2. Renal failurefailure- decrease decreased d renal renal excretio excretion n of potassium potassium 3. Hypoal Hypoaldos doster teroni onism sm and Addis Addison’ on’ss disease disease 4. Improp Improper er use use of potass potassium ium supplem supplement entss Other factors 1. Pseudohyper Pseudohyperkalemi kalemiaa- tight tourniqu tourniquet et and hemolysis hemolysis of blood blood sample, marked marked leukocytos leukocytosis is 2. Trans Transfus fusion ion of “old “old”” banked banked blood blood 3. Acidosis 4. Sever Severee tiss tissue ue traum traumaa Increased potassium in the body Causing irritability of the cardiac cells Possible arrhythmias!!
The Nursing Process in Hyperkalemia Potassium Excess (Hyperkalemia) Clinical Manifestations By far the most clinically important effect of hyperkalemia is its effect on the myocardium. Cardiac ac effe effect ctss of an eleva elevate ted d seru serum m potas potassi sium um leve levell are are usua usuall lly y not not signi signifi fica cant nt belo below w a Cardi concentration of 7 mEq/L (SI: 7 mmol/L), but they are almost always present when the level is 8 mEq/L (SI: 8 mmol/L) or greater. As the plasma potassium concentration is increased, disturbances in cardiac conduction occur. The earliest changes, often occurring at a serum potassium level greater than 6 mEq/ L (SI: 6 mmol/L), are peaked narrow T waves and a shortened QT interval. If the serum potassium level continues to rise, the PR interval becomes prolonged and is followed by disappearance of the P waves. Finally, there is decomposition and prolongation of the QRS complex. Ventricular dysrhythmias and cardiac arrest may occur at any point in this progression. Notee that that in Sever Severee hyperkalemia cause causess musc muscle le weak weaknes nesss and even even paraly paralysi sis, s, rela relate ted d to a Not depolarization block in muscle. Similarly, Similarly, ventricular conduction is slowed. Although hyperkalemia has marked effects on the peripheral neuromuscular system, it has little effect on the central nervous system. Rapidly ascending muscular weakness leading to flaccid quadriplegia has been reported in patients with very high serum potassium levels. Paralysis of respiratory muscles and those required for phonation can also occur. Gastrointestinal manifestations, such as nausea, intermit tent intestinal colic, and diarrhea, may occur in hyperkalemic patients. ASSESSMENT
Physical Examination 1. Diarrhea 2. Skel Skelet etal al mus muscl clee weakn weaknes esss 3. Abnor Abnorma mall cardi cardiac ac rate rate Subjective Cues 1. Nausea 2. Inte Intest stin inal al pain pain/c /col olic ic 3. Pal Palpita pitati tion onss Laboratory Findings 1. Peak Peaked ed and and nar narro row w T wave wavess 2. ST segment depression depression and shorten shortened ed QT interval interval 3. Prol Prolon onged ged PR inter interva vall 4. Prol Prolon onged ged QRS QRS compl complex ex 5. Disa Disappe ppear aranc ancee of of P wave wave 6. Serum Serum potas potassiu sium m is higher higher than than 5.5 5.5 mEq/L mEq/L 7. Acidosis IMPLEMENTATION ASSIST IN MEDICAL INTERVENTION 1. Monitor Monitor the patient’ patient’ss cardiac cardiac status status with cardiac cardiac machine machine 2. Institute Institute emerg emergency ency therapy therapy to lower lower potassi potassium um level level by: by: a. Administer Administering ing IV calcium calcium gluconat gluconatee- antagonizes antagonizes action action of K on on cardiac conducti conduction on b. Administer Administering ing Insulin Insulin with with dextrose-c dextrose-causes auses temporar temporary y shift shift of K into cells cells c. Administer Administering ing sodium sodium bicarbo bicarbonate-a nate-alkali lkalinizes nizes plasma to cause cause temporary temporary shift d. Admini Administe sterin ring g Beta-a Beta-agon gonist istss e. Administer Administering ing Kayexalat Kayexalatee (cation-exc (cation-exchange hange resin)resin)-draws draws K+ into the bowel bowel NURSING MANAGEMENT 1. Provide Provide continuous continuous monitoring monitoring of cardiac cardiac status, status, dysrhythm dysrhythmias, ias, and potassium potassium levels levels.. 2. Assess Assess for signs of muscular muscular weakness weakness,, paresthes paresthesias, ias, nausea nausea 3. Evaluat Evaluatee and verif verify y all all HIGH HIGH serum serum K levels levels 4. Prevent Prevent hyperkalemia hyperkalemia by encouragi encouraging ng high risk patient patient to adhere adhere to proper potass potassium ium restricti restriction on 5. Correct Correct hyperkalemia hyperkalemia by administer administering ing carefully carefully prescribe prescribed d drugs. Nurses Nurses must ensure that clients clients receiving IVF with potassium must be always monitored and that the potassium supplement is given correctly 6. Assist Assist in hemodialys hemodialysis is if hyperkalemia hyperkalemia cannot be corrected. corrected. 7. Provid Providee client client teachin teaching. g. Advis Advisee patien patients ts at risk risk to avoid eating eating potass potassium ium rich foods, foods, and to use potassium salts sparingly. sparingly. 8. Monitor Monitor patients patients for hypokalemi hypokalemiaa who are receiving receiving potassiumpotassium-spar sparing ing diuretic diuretic CALCIUM Majority of calcium is in the bones and teeth Small amount may be found in the ECF and ICF Normal serum range is 8.5 – 10.5 mg/dL Sources: milk and milk products; diet; IVF and medications Functions: 1. Needed for formation of bones and teeth 2. For muscular contraction and relaxation 3. For neuronal and cardiac function 4. For enzymatic activation 5. For normal blood clotting Regulations: 1. GITGIT- absorbs Ca+ in the intestine; Vitamin D helps to increase absorption 2. Renal regulation- Ca+ is filtered in the glomerulus and reabsorbed in the tubules: 3. Endocrine regulation: Parathyroi Parathyroid d hormone hormone from the parathyroi parathyroid d glands is released released when Ca+ level is low. PTH causes release of calcium from bones and increased retention of calcium by the kidney but PO4 is excreted Calcitonin from the thyroid gland is released when the calcium level is high. This causes excretion of both calcium and PO4 in the kidney and promoted deposition of calcium in the bones. Imbalances- Hypocalcemia= <8.5 mg/dL; Hypercalcemia= >10.5 mg/dL THE ANIONS CHLORIDE The major Anion of the ECF Normal range is 95-108 mEq/L Sources: Diet, especially high salt foods, IVF (like NSS), HCl (in the stomach)
Functions: 1. Major component of gastric juice 2. Regulates serum Osmolality and blood volume 3. Participates in the chloride shift 4. Acts as chemical buffer Regulations: Renal regulation by absorption and excretion; GIT absorption Imbalances: Hypochloremia= < 95 mEq/L; Hyperchloremia= >108 mEq/L
PHOSPHATES The major Anion of the ICF Normal range is 2.5 to 4.5 mg/dL Sources: Diet, TPN, Bone reserves Functions: 1. Component of bones, muscles and nerve tissues 2. Needed by the cells to generate ATP ATP 3. Needed for the metabolism of carbohydrates, fats and proteins 4. Component of DNA and RNA Regulations: Renal glomerular filtration, endocrinal regulation by PTH-decreases PO4 in the blood by kidney excretion Imbalances- Hypophosphatemia= <2.5 mg/dL; Hyperphosphatemia >4.5 mg/dL BICARBONATES Present in both ICF and ECF Regulates acid-base balance together with hydrogen Normal range is 22-26 mEq/L Sources: Diet; medications and metabolic by-products of the cells. Function: Component of the bicarbonate-carbonic acid buffer system Regulation: Kidney production, absorption and secretion Imbalances: Metabolic acidosis= <22 mEq/L; Metabolic alkalosis= >26 mEq/ ACID BASE BALANCE Acids substances that can donate or release protons or hydrogen ions (H+); examples are HCl, carbonic acid, acetic acid. Bases or alkalis substances that can accept protons or hydrogen ions because they have low H+ concentration. The major base in the body bod y is BICARBONATE BICARBONATE (HCO3) Carbon dioxide is considered to be acid or base depending on its chemical association When assessing acid-base balance, carbon dioxide is considered ACID because of its relationship with carbonic acid. Because carbonic acid cannot be routinely measured, carbon dioxide is used. pH- is the measurement of the degree of acidity or alkalinity of a solution. This reflects the relationship of hydrogen ion concentration in the solution. The higher the hydrogen ion concentration, the acidic is the solution and pH is LOW The lower the hydrogen concentration, the alkaline is the solution and the pH is HIGH Normal pH in the blood is between 7.35 to 7.45 SUPPLY AND SOURCES OF ACIDS AND BASES Sources of acids and bases are from: 1. ECF, ECF, ICF and body tissues 2. Foodstuff 3. Metabolic products of cells like CO2, lactic la ctic acids, and ammonia
DYNAMICS OF ACID-BASE BALANCE Acids are constantly produced in the body Because cellular processes need normal pH, acids and bases must be balanced continuously CO2 and HCO3 are crucial in maintaining the balance A ratio of HCO3 and Carbonic acid is maintained at 20 :1 Several body systems (like the respiratory, renal and GIT) together with the chemical buffers are actively involved in the normal pH balance maintained are the process of acid/base acid/base secretion, secretion, production, production, The major ways in which balance is maintained excretion and neutralization 1. REGULATION OF ACID-BASE BALANCE BY THE CHEMICAL BUFFER Buffers are present in all body fluids functioning mainly to prevent excessive cha nges in the pH.
Buffers either remove/accept H+ or release/donate H+ The major chemical buffers are: 1. Carbonic acid-Bicarbonate Buffer (in the ECF) 2. Phosphate buffer (in the ECF and ICF) 3. Protein buffer (in the ICF) The action of the chemical buffer is immediate but limited
2. REGULATION OF ACID-BASE BALANCE BY RESPIRATORY SYSTEM The respiratory center in the medulla is involved Carbon dioxide is the powerful stimulator of the respiratory center The lungs use CO2 to regulate H+ ion concentration Through the changes in the breathing pattern, acid-base balance is achieved within minutes Functions of the respiratory system in acid-base balance: 1. CO2 + H2O H2CO3 2.↑ CO2activates medulla↑RR CO2 is exhaled pH rises to normal 3. ↑ HCO3depresses RR CO2 is retainedBicarbonate is neutralized pH drops to normal 3. REGULATION OF ACID-BASE BALANCE BY THE KIDNEY Long term regulator of the acid-base balance Slower to respond but more permanent Achieved by 3 interrelated processes 1. Bicarbonate reabsorption in the nephron 2. Bicarbonate formation 3. Hydrogen ion excretion When excess H+ is present (acidic), pH fallskidney reabsorbs and generates Bicarbonate and excretes H+ When H+ is low and HCO3 is high (alkalotic). pH rises kidney excretes HCO3 and H+ is retained. Normal Arterial Blood Gas Values Values 1. pH – 7.3 7.355-7. 7.45 45 2. pO2 pO2 – 80-1 80-100 00 mmHg mmHg 3. pCO2 pCO2 – 3535-45 45 mmHg mmHg 4. Hco3 Hco3 – 2222-26 26 mEq/ mEq/L L 5. Base Base defi deficit cit/Ex /Exces cesss – (+/-)2 (+/-)2 6. O2 satu satura rati tion on – 9898-10 100% 0% FACTORS AFFECTING BODY FLUIDS, ELECTROLYTES ELECTROLYTES AND ACID-BASE BALANCE 1. AGE Infants have higher proportion of body bod y water than adults ag e Water content of the body decreases with age Infants have higher fluid turn-over due to immature kidney and rapid respiratory rate 1. GE GEND NDER ER AND AND BODY BODY SIZE SIZE Women have higher body fat content but lesser water content Lean body has higher water content 2. ENVIRO ENVIRONME NMENT NT AND TEMPER TEMPERA ATURE TURE Climate and heat and humidity affect fluid balance 3. DIET DIET AND AND LIFE LIFEST STYL YLE E Anorexia nervosa will lead to nutritional depletion Stress Stressful ful situati situations ons will will increa increase se metabol metabolism ism,, increa increase se ADH causing causing water water retention and increased blood volume Chronic Alcohol consumption causes malnutrition 4. ILLNESS Trauma and burns release K+ in the blood Cardiac dysfunction will lead to edema and congestion 5. MEDICAL MEDICAL TREATMENT TREATMENT,, MEDICATIONS MEDICATIONS AND SURGERY SURGERY Suctioning, diuretics and laxatives may cause imbalances Acid Base Imbalances Metabolic Alkalosis A base bicarbonate excess A result of a loss of acid and the accumulation of bases S/S - serum pH > 7.45, increased serum
HCO3, serum K level less than 4, tetany, tetany, confusion and convulsions Nursing Interventions - watch for s/s of hypokalemia, LOC and seizure precautions Metabolic Acidosis A base bicarbonate deficit Comes from too much acid from metabolism and loss of bicarbonate (Kussmaul’s Respirations), Shock, stupor, coma S/S - Serum pH <7.35, Increased K+ level, DKA (Kussmaul’s Nursing Intervention - Give HCO3/Monitor K+ levels Respiratory Alkalosis A deficit of carbonic acid caused by hyperventilation S/S - decreased levels of CO2 and increased levels of pH, HCO3 near normal nor mal Nursing Interventions - monitor for anxiety and observe for signs and symptoms of tetany Respiratory Alkalosis A carbonic acid excess Caused by an condition that interferes with the release of CO2 from the lungs (sedatives, COPD, narcotics etc.) S/S - serum pH < 7.35, increased serum CO2 levels> 45 mm Hg, serum K increased, cyanosis Nursing Interventions - Provide O2, Semifowlers position, seizure precautions Interpretation Arterial Blood Gases
If acidosis the pH is down If alkalosis the pH is up The respiratory function indicator is the PCO2 The metabolic function indicator is the HCO3
Step 1
Look at the pH Is it up or down? If it is up - it reflects alkalosis If it is down - it reflects acidosis
Step 2
Look at the PCO2 Is it up or down? If it reflects an opposite response as the pH, then you know that the condition is a respiratory imbalance If it does not reflect an opposite opp osite response as the pH - move to step III
Step 3
Look at the HCO3 Does the HCO3 reflect a corresponding response with the pH If it does then the condition cond ition is a metabolic imbalance
