Fluid and Electrolytes Student Notes - Winter 2024 PDF

Week 5 Fluid & Electrolyte Balance NURS.2500 Fall 2022 CNURS.2500 STUDENT LEARNING OUTCOMES CONCEPT OF FLUID AND ELECTROLYTES Giddens 2021 PART ONE: FLUID & ELECTROLYTE BALANCE Homeostatic mechanisms are in place to maintain optimal fluid balance in a variety of conditions. Giddens, 2021 WATER DISTR...

Week 5 Fluid & Electrolyte Balance NURS.2500 Fall 2022 CNURS.2500 STUDENT LEARNING OUTCOMES CONCEPT OF FLUID AND ELECTROLYTES Giddens 2021 PART ONE: FLUID & ELECTROLYTE BALANCE Homeostatic mechanisms are in place to maintain optimal fluid balance in a variety of conditions. Giddens, 2021 WATER DISTRIBUTION IN THE BODY Water or fluid in the body is in one of three compartments: In the extracellular space: 1. Vascular space/Plasma: in our blood vessels 2. Interstitial space: The fluid is in the space between cells 3. In the intracellular space: The fluid in the space inside the cells ELECTROLYTE DISTRIBUTION IN THE BODY Focus mainly on Sodium (Na+) and Potassium (K+) The body is designed to keep these specific Extracellular: Vascular/Blood concentrations to maintain homeostatic norms. When we draw labs, we can only measure the concentrations of these electrolytes IN Most Na+hard to the blood. (easiest to measure, measure amounts inside cells) Intracellular Little K+ Most K+ Little Na+ LAB VALUES REFLECTING F & E BALANCE Lab values for a patient in perfect homeostasis. Everything within normal range: No warning signs for fluid volume excess or fluid volume deficit Hemoglobin and hematocrit in normal range show optimal levels of body water present in the blood (no hemodilution or hemoconcentration occurring) Labs Reference Range Result Serum Potassium (K+) 3.5-5 mmol/L 4.1mmol/L Serum sodium (Na+) 135-145mmol/L 139mmol/L Serum Albumin 35-50g/L 41g/L Hemoglobin 140-180 g/L Male 120-160 g/L female 150g/L Hematocrit 0.42-0.52 (male) 0.37-0.47 (female) 0.45 Fluid and Electrolytes | Hemoconcentration vs Hemodilution Still the same amount of HGB/HCT in each, it’s the water that YouTube makes it look falsely high or falsely low Labs Reference Range Result Serum Potassium (K+) 3.5-5 mmol/L 4.1mmol/ 4.5 L mmol/L Serum sodium (Na+) 135-145mmol/L Serum Albumin 35-50g/L 139mmol/ L 141mmol 141mmol/ L /L 41g/L Hemoglobi n 140-180 g/L Male 120-160 g/L female 150g/L 0.42-0.52 (male) 0.37-0.47 (female) 0.45 Hematocrit Result Result 4.9 mmol/L 40g/L 39g/L 140g/L 142g/L 0.42 0.47 Trends - Baselines What do we look at and why....Why? Why? Why? the body does not typically have high albumin levels, but they can occur due to dehydration., Albumin is a large protein that normally does not pass through the kidneys' filtration system in significant amounts. However, when the kidneys are damaged, they may allow albumin to escape through the glomeruli (the filtering units) and be excreted in the urine. This condition is known as albuminuria or proteinuria. The presence of albumin in the urine is a common marker for kidney damage or disease, particularly in conditions such as diabetes or hypertension, which can cause kidney damage Fluid Shifts 10 Regulation of Water Balance Too much water loss, blood Na+ concentration rises, hypothalamus detects this Hypothalamus-Pituitary Gland (in brain) Regulation of Water Hypothalamic osmoreceptors – sense increased osmolality (too many particles, not enough fluid) 1. Thirst triggered (decreased in older adult) 2. ADH release from Pituitary Gland – in kidney free water reabsorption (not Na) RAAS: Recall this from our earlier classes on hypo/hypertension. Ensure you understand how Aldosterone stimulated the kidneys to reabsorb water and Na+. ADH: kidneys reabsorb more water, NOT Na+. This dilutes our blood so the Na+ concentration drops 11 Gastrointestinal (GI) Regulation of Water Intake: Source of new water for the body Output: Diarrhea and vomiting may lead to excessive water loss and electrolyte loss Genitourinary Regulation of Water Output: Urine Renal excretion provides largest output Insensible Water Loss – approx. 900ml per day Water loss from breathing and insensible perspiration (water only) Excessive sweating (sensible perspiration) may lead to excessive water and electrolyte loss (fever, hot environment) Water used in metabolic processes 13 Age-Related Considerations - Increased risk of imbalances Reduced renal function Reduced hormone regulation Reduced thirst trigger Reduced temperature regulation Impaired functional and cognitive ability may interfere with oral consumption of water 14 Nursing Implementation 1. Intake and Output: (GI and GU system) Use of 24-hour record of I&O (Intake & Output) Types of fluid Intake – drinking, eating, IVs, GI tubes Types of fluid Output – urine, vomit, diarrhea, sweat, breathing 2. Daily Weight Measurements: Accurate daily weight estimates volume status Rapid increase of 1 kg body weight approximates 1000 mL (1 L) of fluid retention Obtained under standardized conditions (same time every day, with the same clothes, same scale) 15 Sources of Fluid and Sodium Oral Intake: “free” water (“tap” water) – no significant Na, will provide water to dilute plasma Na, if un-needed the kidneys will excrete excess water Electrolyte-replacement beverages (sports drinks, Pedialyte) provide electrolytes commonly lost through sweat, vomiting, diarrhea as well as water Food and other beverages – most food also contains water Caffeine beverages may result in increased urine output When a patient cannot swallow fluids/foods – GI tube may be inserted down a nasal passage and into the stomach or small bowel – fluids/liquid food may be instilled through this tube (tube feeds) 16 WATER INTAKE / OUTPUT SOURCES Intake Output Liquid 1000-1200 mL Lungs 400-500 mL Food 800-1000 mL Skin 300-500 mL Oxidation of food 200-300 mL Urine 1000-1500 mL Total ~2000-2500mL Feces 100 mL Total ~2500 mL Why is intake and output calculation so important for nurses so know? How could you measure fluid balance if some of the in and out was not recorded? Fluid Volume Deficit Fluid Volum e Excess o o o Fluid Spacing First spacing – normal ICF ECF Second spacing – edema in tissue (too much in IF, may cause too much in ICF) Third spacing – accumulates in body spaces – “potential spaces” – ascites in abdominal cavity, pleural effusion in pleural space, blisters, etc. – not able to move it back into the plasma 20 CIRCULATING VOLUME TERMS Hypovolemia Hypervolemia Low circulating volume High circulating volume Can occur with loss of normal body fluids (diarrhea, fistula drainage, hemorrhage), decreased intake, or plasma-to-interstitial fluid shift (3rd spacing) May result from excessive intake of fluids, abnormal retention of fluids (CHF), or interstitial-toplasma fluid shift AKA dehydration, fluid volume deficit Goal: Treat cause, replace water & electrolytes, give blood if due to hemorrhage. IV fluids to replace quickly AKA overhydration, fluid volume overload Goal: remove Na+ & water without causing other electrolyte imbalances Treat with diuretics & fluid restriction Typically associated with electrolyte imbalance Hypovolemia: from Vomiting, Diarrhea, suctioning gastric or intestinal fluid, wound drainage, kidney disease, overuse of some diuretics, hemorrhage, massive diaphoresis Clinical manifestations: ↓Weight ↓B/P weak thready pulse (1+) ↑HR (from SNS response-baroreceptors) trying to maintain CO Flat neck veins Prolonged capillary refill Pre-syncope, dizziness or syncope ↓blood flow to kidney →RAAS & Aldosterone low urine output-oliguria ↑ urine Specific Gravity (high urine Slow fluid loss→ ↓tissue turgor (tenting) Mucosa dry, tongue furrowed/cracked Constipation, hard stools Eyes sunken If extreme loss of tears and sweating Infants may have sunken fontanelle Syncope is the medical term for fainting or passing out, which happens when your brain doesn't get enough blood and oxygen temporarily. Pre-syncope, on the other hand, refers to feeling like you're about to faint without actually losing consciousness Hypervolemia: the opposite… from IV fluid overload (NS, R/L) many pathos that increase aldosterone or cause the kidney to fail and some drugs like corticosteroids Clinical manifestations: ↑ weight “Circulatory overload” Bounding pulses 4+ Distended neck veins ↑ B/P ↑ hydrostatic pressure in capillaries will cause “fluid leak” into interstitial space & body cavity space Edema (lower legs, sacrum, around eyes) Frothy pink sputum from pulmonary edema…can lead to respiratory failure FLUID & WEIGHT: WHAT IS THE CONNECTION? A patient’s morning weight is 63.5kg. The patient drinks 700mL at breakfast then vomits 500mL and has a diarrhea stool of 800mL. Assuming no insensible water loss, what is the patient’s weight now? Is this a more accurate measurement than the I & O record? Does this tell us about electrolyte balance? DRAG N DROP BP 158/96 Edema Cause may be renal failure constipation Coughing up sputum HR 117 Hypovolemia Thread y pulses BP 89/56 dizziness Rapid weight gain Boundin g pulse oliguria Distended jugular vein Hypervolemia Poor skin turgor Rapid weight loss IV Fluids IV Purposes: FLUIDS Maintenance When oral intake is not adequate Replacement When losses have occurred Isotonic: expands only the ECF Used frequently Hypertonic: initially raises the osmolality of ECF and expands it. Also draws fluid out of cells Used relatively infrequently in special circumstances Need special monitoring Chance for intravascular fluid volume excess & Hypotonic: provides more water than cellular dehydration electrolytes, dilutes the ECF. Moves water into cells TYPES OF IV FLUIDS CRYSTALLOIDS: 1. SALINE 2. 1. 3. 1. NS 0.9% ½ NS 3% NS DEXTROSE D5W D51/2NS D10W ELECTROLYTE RL/LR COLLOIDS 1. ALBUMIN IV SOLUTIONS: CRYSTALLOIDS Fluids for IV administration that supply water and electrolytes Better for treating dehydration than for expanding the plasma volume Help to maintain osmotic gradient between extravascular and intravascular compartments Used as maintenance fluids Have a plasma volume-expanding capacity that is related to sodium concentration Do not contain proteins (colloids) Contain fluids and electrolytes that are normally found in the body To compensate for insensible fluid losses To replace fluids To manage specific fluid and electrolyte disturbances To promote urinary flow IV SOLUTIONS: CRYSTALLOID: SALINE SOLUTIONS Normal Saline- NS 0.9% 0.45% Normal Saline- ½ NS Isotonic Hypotonic 3% Saline Hypertonic No calories Free water, NA, and Cl- Expands ECF volume Promotes movement of water from ECF to ICF Caution—overuse may lead to cellular swelling Preferred fluid for immediate response Risk for fluid overload higher Does not change ICF volume Caution-must be administered slowly and with extreme caution May cause dangerous intravascular volume overload & pulmonary edema IV SOLUTIONS: CRYSTALLOID: DEXTROSE SOLUTIONS Dextrose 5% in Water D5W Isotonic in the bag Provides 170 kcal/L Free water-becomes hypotonic Moves into ICF: caution with ↑Intra Cranial Pressure Dextrose 10% in Water- D10W Dextrose 5% in 0.45% Normal Saline- D5 ½ NS Hypertonic Provides 340 kcal/L Free water Upper limit of dextrose concentration that may be infused peripherally Hypertonic in the bag Hypotonic in the body Provides calories Prevents ketosis IV SOLUTIONS: CRYSTALLOID: MULTIPLE ELECTROLYTE Lactated Ringer’s (LR or RL) SOLUTIONS Isotonic More similar to plasma than NS Has K, Ca, PO4, lactate (metabolized to HCO3) Expands ECF Common replacement fluid IV SOLUTIONS: COLLOIDS AKA: Plasma expanders Protein substances that increase the colloidal osmotic pressure (COP) and move fluid from the interstitial compartment to the plasma compartment Common Colloids 5% Albumin 25% Albumin When the protein level in the blood falls, fluid shifts out of the blood vessels & into tissues. Colloids are used to treat this condition Indications Treat a wide variety of conditions Are superior to crystalloids in plasma volume expansion but more expensive Contraindications Known drug allergy Hypervolemia Severe electrolyte disturbance https://diabetesstore.com.bd/albuminhuman-20-100-ml-iv-infusion.html APPLICATION EXERCISE The IV fluid _______________ is isotonic, so it is ideal for expanding the vascular space. _____________ is a colloid fluid that can increase the oncotic pressure in the blood. A person with severe dehydration should be treated with ______________ to replenish intracellular fluid ______________ is an IV fluid that contains no sodium. The IV solution known as __________________expands extracellular fluid volume and contains many electrolytes NOW WE KNOW ABOUT FLUID, WHAT ABOUT ELECTROLYTES? We will cover the following electrolyte imbalances: Hyponatremia (low Na+) Hypernatremia (high Na+) Hypokalemia (low K+) Hyperkalemia (High K+) HYPONATREMIA Low serum sodium Can be due to lack of Na or too much water Etiology: Relative excess of water in relationship to sodium 1. Gaining more water than salt Diseases that cause too much ADH Serum is more dilute than normal…osmolality is low 2. to be secreted—kidney reabsorbs Low osmolality causes fluid to shift from the plasma water & not Na (SIADH) where water concentration is high into the cells where it is low 1. Pain, nausea, stressors (common in post-op patients) Clinical Manifestations 3. Excessive IV fluids without Na (D5W) or hypotonic solutions 0.45% NS Non-specific CNS dysfunction R/T cells (brain cells) swelling with fluid Malaise Anorexia N & V Headaches → confusion → lethargy → seizures → coma Severe swelling in brain → herniation/fatal Excessive water drinking Meds: diuretics HYPERNATREMIA Can be due to lack of water or too much Na Relative excess of sodium in relation to water Etiology: 2 ways 1. Gain of salt more than water Highly concentrated tube feeds, hypertonic IV fluids (3% NS), drinking sea water, older folks with diminished thirst High serum sodium High Na in the plasma (elevated serum osmolality) ‘pulls’ fluids out of the IF and ICF cells shrink & become dysfunctional Clinical Manifestations: Again CNS dysfunction but now because of shrinking brain cells Lethargy → agitation → seizures → coma Intense Thirst (diminished in elderly) Oliguria Severe hypernatremia → death 2. Loss of more water than salt Diabetes Insipidus opposite of SIADH… lack of ADH so water is not reabsorbed Prolonged Vomiting, Diarrhea, diaphoresis TREATMENT FOR NA IMBALANCES Hypernatremia Hyponatremia Caused by water loss: Caused by Water excess: Treat underlying cause Fluid restriction Replace with isotonic fluid like NS 0.9% Caused by excess sodium: If seizures can use small amount of Saline 3% to increase sodium (dangerous) Treat underlying cause Caused by fluid (salt and water) loss: Replace with salt-free IV solution like D5W IV replacement of fluids containing sodium Excrete sodium with diuretics LAB VALUES REFLECTING F & E BALANCE What do you notice about these lab values? Labs Reference Range Result Looking at the hemoglobin and hematocrit levels, Do you think this is due to sodium gain or water loss? Why do you think that? Serum Potassium (K+) 3.5-5 mmol/L 4.8mmol/L Serum sodium (Na+) 135-145mmol/L 149mmol/L Serum Albumin 35-50g/L 49g/L Hemoglobin 140-180 g/L Male 120-160 g/L female 188g/L Hematocrit 0.42-0.52 (male) 0.37-0.47 (female) 0.58 What symptoms might you see? What do you think the treatment should be? QUESTION A nurse is assessing a patient with kidney disease who mistakenly received an infusion of 1000mL of D5W over 30 minutes instead of 100mL over 30 minutes as ordered. The patient has a normal potassium level but a decreased sodium level is noted. Think 2 conditions which you will see various clinical manifestations for. What will the nurse expect to see on assessment? Cardiovascular symptoms Neurological symptoms Respiratory symptoms Other symptoms POTASSIUM Potassium is responsible for: Muscle contraction 95% of the body’s potassium is intracellular Transmission of nerve impulses Potassium levels are critical to normal body Regulation of heartbeat Maintenance of acid–base balance function Many other functions in the body Sources: Potassium is the most abundant positively charged electrolyte inside cells Fruit and fruit juices, fish, vegetables, poultry, meats, dairy products Excess K is excreted via kidneys Impaired kidney function leads to higher serum levels, possibly toxicity POTASSIUM Hypokalemia deficiency of potassium (less than 3.5 mmol/L) 3 major Causes:. Potassium Loss. Potassium shift into cells. Lack of potassium intake GI loss: Diarrhea, Vomiting, NG suction Diuretics Increased insulin Alkalosis Tissue repair ↑ epinephrine (stress) Starvation Low potassium diet POTASSIUM HYPOKALEMIA CLINICAL MANIFESTATIONS Class: Vitamin Generic: Potassium Supplement Therapeutic Effects: Increased potassium levels Mechanism of Action: Potassium is the principal intracellular cation of body tissues. Administration Indications Contraindications Side Effects Nursing Considerations If mild hypokalemia and non-symptomatic, patient may receive oral Prevention of potassium depletion Renal impairment with oliguria/anuria CVS: Arrhythmias GI: Cramping, N/V, diarrhea, unpleasant taste, gastric irritation Assess potassium levels pre and post administration Particularly if IV route given If moderate hypokalemia and/or symptomatic, patient may receive IV May be in liquid or pill form. Liquid is easier to drink in juice or diluted with water Untreated Addison’s disease Treatment of potassium depletion Acute trauma Drug-Drug Interactions: Increased potassium with Spironolactone or captopril Diuretics 1. 1. 1. 2. 3. 4. 2. 1. 1. 2. 3. 4. Furosemide Loop Diuretic Inhibits sodium potassium pump in ascending loop of Henle, decreasing reabsorption of sodium and water Indications: edema, HTN Contraindications: electrolyte imbalances, hypovolemia Side effects: hypotension, hypokalemia, tinnitus Spironolactone Potassium sparing diuretics Inhibition of water and sodium reabsorption in the kidney while saving potassium Indications: Like furosemide however counteract potassium loss (may be used with furosemide) Contraindications: Hyperkalemia, hypovolemia Side effects: hyperkalemia, hypotension Diuretic Nursing Considerations: Monitor BP, weights, urine output, labs Have you followed up with the reason why you gave it LAB VALUES REFLECTING F & E BALANCE What do you notice about these lab values? Labs Reference Range Result What symptoms might you see? Serum Potassium (K+) 3.5-5 mmol/L 5.9mmol/L What are you most concerned about and why? Serum sodium (Na+) 135-145mmol/L 142mmol/L What do you think the treatment should be? Serum Albumin 35-50g/L 36g/L Hemoglobin 140-180 g/L Male 120-160 g/L female 144g/L Hematocrit 0.42-0.52 (male) 0.37-0.47 (female) 0.45 FLUID AND ELECTROLYTE IMBALANCE: EXEMPLARS What can happen when ADH is not secreted in alignment with this homeostatic mechanism? Now that we have learned all about the different imbalances that occur, we will learn about some specific hormone imbalances in the body that have a profound effect on fluid and electrolyte balance. Recall: ADH = antidiuretic hormone Hypothalamus-Pituitary Gland (in brain) Regulation of Water Hypothalamic osmoreceptors – sense increased osmolality (too many particles, not enough fluid) thirst triggered (decreased in older adult) ADH release from Pituitary Gland – in kidney Na) free water reabsorption (not ADH Two extremes: DYSFUNCTION – WHAT CAN HAPPEN? Syndrome of inappropriate ADH (SIADH) – excessive ADH secretion Diabetes Insipidus (DI) – lack of ADH secretion SIADH – WHAT IS THE PATHOPHYSIOLOGY? RECALL : ADH released despite low or normal serum osmolality Causes of SIADH: ADH-secreting tumour Pituitary tumour Meningitis/brain trauma Lewis et al. (2014) SIADH – WHAT ARE THE MANIFESTATIONS? Fluid retention = decreased urine output and increased body weight Symptoms are primarily related to decreased Na+ Muscle cramps, twitching and weakness Vomiting, abdominal cramping, anorexia Lethargy, confusion, headache, seizure, coma This Photo by Unknown Author is licensed under CC BYNC-ND SIADH – HOW IS IT DIAGNOSED? Simultaneous measurements of serum and urine osmolality Serum osmolality – decreased Urine osmolality – increased Other lab results: Decreased serum Na+ Decreased Hgb and Hct https://www.emergency-live.com/health-and-safety/peecolour-causes-diagnosis-and-when-to-worry-if-your-urine-isdark/ EXEMPLAR: SIADH You are the nursing student caring for Joan, a 49 year old patient who uses she/her pronouns. Joan has been diagnosed with lung cancer (small cell carcinoma). Today Joan reports feeling ill, having very small amounts of concentrated urine, and feeling like she cannot catch her breath. She is diagnosed with SIADH. Based on what you know about SIADH, make up the lab values for Joan. Give rationale. Labs Reference Range Result Serum sodium (Na+) 135-145mmol/L _____mmol/L Hemoglobin 140-180 g/L Male 120-160 g/L female ______g/L Hematocrit 0.42-0.52 (male) 0.37-0.47 (female) _______ Biggest concern Treatment QUESTION What other symptoms might you see? What are you most concerned about and why? What do you think the treatment should be? Cardiovascular symptoms Neurological symptoms Respiratory symptoms Other symptoms DIABETES INSIPIDUS – WHAT IS IT? RECALL : decreased production or secretion ADH (or lack of renal response to ADH) = inability to conserve water Two types: Central (neurogenic) – interference with ADH synthesis or release Nephrogenic – inadequate renal response to ADH Primary (psychogenic) – excessive water intake https://abcnews.go.com/GMA/juryrules-radio-station-jennifer-strangewater-drinking/story?id=8970712 Lewis et al. DI – WHAT ARE THE MANIFESTATIONS? “Dying of thirst” polydipsia abrupt polyuria fatigue constipation Do these symptoms look familiar to you? What do they make you think of? weight loss dehydration decreased LOC, seizures, shock, coma This Photo by Unknown Author is licensed under CC BY-SA DI – HOW IS IT TREATED? Treat primary cause if possible Goal is to maintain fluid and electrolyte balance Central DI Acute – hypotonic IV saline to replace urine output DDAVP (desmopressin acetate) – hormone replacement d/t lack of ADH Nephrogenic DI Dietary measures (low sodium,