Fluid & Electrolyte Basics Disclaimer - Pocket Prof Apps has used reasonable efforts to ensure that the information provided is both accurate and current. However, your education is ultimately your responsibility, and Pocket Prof Apps makes no guarantee to the accuracy or applicability of any information provided, and assumes no liability for your reliance on any information we provide. Further, the information provided in resources published by Pocket Prof Apps represents the understanding and opinions of the presenters and authors, and may or may not be consistent with the opinions or preferences of your own professors. We therefore recommend that you use information provided by Pocket Prof Apps to supplement your other education resources, and not replace your own study, group discussions, and class lectures. ©2013 www.pocketprofnursing.com by Pocket Prof Apps Homeostasis • Body fluids are in constant motion transporting nutrients, electrolytes, and oxygen to cells while carrying away waste products • Many disease and treatments affect this balance Water • More important to life than any other nutrient – – – – – – Carries nutrients and waste products Participates in metabolic reactions, food digestion Solvent for minerals, vitamins, glucose Lubricant and cushion for the joints, eyes, spinal cord Aids in regulation of body temp Maintains blood volume • 60% of an adult’s body weight (more in a child, less in the elderly) • Found in foods (but not in alcohol) • Daily need is about 2000 mL • 1 liter of water weighs 1 kg Fluid Intake and Loss • Intake sources – Liquids (1500 mL/day) – Solid foods (800 mL/day) – Metabolism (300 mL/day) • Fluid loss routes – Kidney (1200-1500 mL/day) – Skin (500-600 mL/day) – Lungs (400 mL/day) – GI tract (100-200 mL/day) – Drainage from fistulas/drains, GI suction, salivation Intake Measurable Output Measurable Oral fluid, tube feedings Urine Parenteral fluid Emesis Enemas Feces Retained irrigation fluid Drainage from body cavities Not Measurable Not Measurable Solid foods Sweating Metabolism Vaporization through lungs Electrolytes • Chemicals dissolved in the body fluid, distribution affects fluid balance • Regulated by intake, output, acid-base balance, hormones, and cell integrity • Sodium – Major extracellular electrolyte – Controls and regulate water balance • Potassium – Major intracellular electrolyte – Helps maintain intracellular water balance – Transmit nerve impulses to muscles and contract skeletal and smooth muscles F&E Labs • Sodium (Na) 135-145 – Determines whether water is retained, excreted, or moved – Imbalances cause neuro problems • Potassium (K) 3.5-5.0 – Increased with poor kidney function – Decreased with excessive urination, diarrhea, vomiting – Imbalances cause cardiac problems • Chloride (Cl) 96-106 – Works with sodium to maintain osmotic pressure – Increased with poor kidney function – Decreased with excessive vomiting or diarrhea F&E Labs • Calcium (Ca) 9.0-10.5 – Transmission of nerve impulses, heart and muscle contractions, blood clotting, formation of teeth and bone – Requires Vit D for absorption • Phosphate (PO4) 3.0-4.5 – Balance is intertwined with calcium • Other tests – BUN 6-20 – Creatinine 0.6-1.3 – Hematocrit 42-52% (males), 37-47% (females) – Total protein, albumin Lab Normals – Magic 4 Electrolyte Range Magic 4 Potassium 3.5 – 5.5 4 Chloride 98 – 106 104 Sodium 135 - 145 140 pH 7.35 – 7.45 7.4 pCO2 35 – 45 40 HCO3 22 – 26 24 FYI – Hematocrit normal is 3 times the hemoglobin (10-14 is normal) Osmolarity and Osmolality • Indicates the water balance of the body • Serum osmo is 285 - 295 mOsm/kg – High is water deficit (concentrated) – Low is water excess (dilute) • Urine osmo is 50-1200 mOsm/kg (avg - 500800 mOsm/kg) • Together are used to determine what is causing a sodium imbalance Distribution of body fluids & Electrolytes • Intracellular (2/3) – K+, PO4• Extracellular (1/3) – Na+, Cl– Interstitial (lymph) and transcellular (cerebrospinal, pleural, peritoneal, synovial fluids) – Intravascular (blood plasma) Regulation of Fluid & Electrolyte Movement Diffusion Active Transport Filtration Osmosis Regulation of Water Balance Kidneys Kidneys (JG cells) (adrenal cortex) • Sense low Na, low volume • Release renin • Converts angiotensinogen to angiotensin I which converts to angiotensin II • Stimulates release of aldosterone (RAAS) • Senses low serum osmo or low Na • Releases aldosterone • Reabsorbs Na into the blood, increases K excretion in the urine • Increases serum osmo Hypothalamus • Senses high serum osmo or high Na • Stimulates thirst • Triggers release of ADH (vasopressin) from posterior pituitary • Retains water in the blood • Concentrates urine • Mildly constricts blood vessels • Decreases serum osmo Heart • Senses high volume through stretch receptors in the right atrium • Secretes ANP, BNP • Inhibits ADH • Stops the RAAS • Increases Na excretion through the urine • Dilates blood vessels • Decreases serum osmo Fluid Spacing • First spacing – Normal • Second spacing – Edema • Third spacing – Ascites – Burn edema IV Fluids • Isotonic – NS – D5W – LR • Hypertonic – 3% NS – D51/2NS – D10W • Hypotonic – 1/2NS • Plasma Expanders Gerontologic considerations • Percent of body weight of water is decreased • Structural changes in the kidney and decreased renal blood flow – – – – – • • • • • Decreased GFR Decreased creatinine clearance Loss of ability to concentrate urine and thus conserve water Decrease in renin and aldosterone Increase in ADH and ANP Loss of subcutaneous tissue Decrease in thirst mechanism Musculoskeletal changes Mental status changes Incontinence Assessment Considerations • History – nutrition, I/Os, insensible losses, use of diuretics/laxatives, weight changes, kidney or endocrine disorders, LOC, mental status, depression, eating disorders, alcohol intake • Physical – hydration status, skin turgor, mucous membranes, I/Os • Dx tests – electrolyte levels, BUN, glucose, creatinine, pH, bicarb, osmolality, Hgb, Hct, urine dipstick, urine pH, urine specific gravity • Watch for more videos coming soon. • Check out our website (www.pocketprofnursing.com) for my notes, videos, and games to test your knowledge. • Watch for more Med Surg videos and app coming soon. © 2013 www.pocketprofapps.com Bringing practical nursing education to your mobile devices - 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Image Attribution • • • • • • • Slide 1 – Flickr by Randy Le'Moine Photography, www.pixabay.com, no attribution required Slide 2 – Flickr by TipsTimes, By Anna Frodesiak (Own work) [Public domain or CC0], via Wikimedia Commons Slide 3 – www.pixabay.com no attribution required Slide 10 - http://antranik.org/fluid-compartments-within-the-human-body/ Slide 13 – By James Heilman, MD (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons Slide 14 - http://medxforum.com/vb/showthread.php?483-What-is-the-name-ofThis-sign-What-is-your-Differential-Diagnosis, https://myspace.com/dancingsquids/photos/64974051 Slide 15 - "Photo by Chalmers Butterfield"." [CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5), GFDL (www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], from Wikimedia Commons