Electrolytes, Fluid, and pH Balance PDF

Denver College of Nursing ADN and BSN Programs pH, Electrolyte, & Fluid Balance Distribution of Body Fluids Total body water – all fluids 60% of weight Inside cell Intracellular fluid (ICF) 2/3 TBW Fells Extracellular fluid (ECF) 1/3 TBW  In Interstitial fluid – between...

Denver College of Nursing ADN and BSN Programs pH, Electrolyte, & Fluid Balance Distribution of Body Fluids Total body water – all fluids 60% of weight Inside cell Intracellular fluid (ICF) 2/3 TBW Fells Extracellular fluid (ECF) 1/3 TBW  In Interstitial fluid – between cells 29 vesals  Intravascular fluid – blood plasma 2b_  Lymph, synovial, intestinal, CSF, sweat, urine, pleural, peritoneal, pericardial and intraocular fluid Cells live in a fluid environment with electrolytes and acid-base concentrations maintained within a narrow range Changes or shifts in concentrations → radically alter metabolism → life threatening  Sodium (Na+) outside the cell mostly  Primary ECF cation  Regulates osmotic forces  Role ▪ Neuromuscular irritability, acid-base balance, cellular reactions, and membrane transport  Chloride (Cl-) CI mimics Nat  Primary ECF anion  Provides electroneutrality I Sodium and Water Balance Balance between Na+ and H2O  ↑ or ↓ of salt = ↑ or ↓ water 0  H2O follows Na + IT or Nat polls Tonicity – change in concentration of solutes (salt) with relation to solvent (water) Tonicity giving solution to same as in the cel Equal concentration Normal saline  Isotonic – ECF = 0.9% NaCl  iso-osmolar = no change in cells a elevated concent no leaves cell  Hypertonic – ECF > 0.9% NaCl shores Ells coo  (↓ H2O or ↑ salt) cells ________ Shrink o a a aa Lowered H2o goes in  Hypotonic – ECF < 0.9% NaCl swell  (↑ H2O or ↓ salt) cells ________ swen  Most abundant positive ion  90% ECF cations  135 – 145 mEq/L elevated sodium blood in  Hypernatremia - > 145 mEq/L God blood in  Hyponatremia - < 135 mEq/L ICP Is sweT intercranial Pressure Hypernatremia ↑ Na or ↓ H2O 00 H2O movement ICF → ECF(interstitial)  From:  IV therapy – acidosis (NaHCO3)  Cushing's Syndrome - ↑ ACTH → aldosterone  fever, respiratory infection - ↓ H2O  diabetes, diarrhea - ↓ H2O  coma - ↓ H2O intake vital Manifestations (↑functions) of nervous systemare – Intracellular dehydration: convulsions, thirst, fever, muscle twitching, hypertension, hyperreflexia w I ringingmÉImb  c Hyponatremia   00 ↓ Na or ↑ H2O H2O movement ECF(interstitial) → ICF  From:  Vomiting, diarrhea, GI suction, burns, diuretics, D5W replacement (isotonic sol’n)  Manifestations (↓functions) of nervous system  Lethargy, confusion, depressed reflexes, seizures, coma, hypotension, tachycardia, ↓ urine output tithexes  Most life threatening = cerebral edema and increased intracranial pressure chubbyemu mom duanz 2 gal of 420 youtube  Primary ECF anion CI mimics Nat  Electroneutrality with Na+ Hypochloremia Hyponatremia ICP  Result of hyponatremia or ↑ HCO3  Vomiting = loss HCl = loss of Cl- in blood α  Cystic fibrosis  Imbalance of Na+ and Cl- transport across epithelium  Major intracellular electrolyte  98% intracellularTow levels in blood  Na/K ATPase Pump  Norm = 3.5 – 5.0 mEq/L mainly affets  Affects resting potential muscle  Transmission and conduction of nerve impulses, normal cardiac rhythm, skeletal and smooth muscle contractions: “action potentials”  Hypokalemia excitability lengthens threshhold Hyperkalemia I excitability shortens threshold k opens open no at  excitability Iad ad ew at New  new I at old  K is only electrolyte affected by PH  Change in pH GREATLY affects K+ balance H At Acidosis causes: É t  ↑ H+ inside cell → K+ moves out I Ht (electroneutrality) Hyperkalemia kty Alkolosis causes:  ↓H+ inside cell → K+ into cell Tokalemia Hypokalemia  K+ < 3.5 mEq/L  From↓ intake, ↑ loss, or↑ entry into cells  Lowers resting potential = membrane hyperpolorizations  ↓ neuromuscular excitability  Manifestations: skeletal muscle weakness, smooth muscle atony, and cardiac dysrhythmias Hyperkalemia  K+ > 5.0 mEq/L  ↑ shift from ICF (acidosis), ↓ renal excretion, insulin deficiency or cell trauma  Mild attacks  Raises resting potential = ↑ excitability  ↑ neuromuscular irritability/activity – tingling of lips & fingers, restlessness, intestinal cramps/diarrhea, cardiac dysrythmias  FYI Sedative LOC Paralytic RR attack KCI iaT PUSH Potassium NeverIV  Needed for bone, teeth, blood clotting, muscle contractions, neurotransmitter release, hormone secretion, cell receptor function  99% in bone mainly affects skeletal  f Affects threshold potential muscle  Hypocalcemia=↓ block of Na into cell = ↑ neuromuscular excitability (muscle cramps)  ↓ Threshold potential = More excitable  Hypercalcemia=↑ block Na =↓ neuromuscular excitability (muscle weakness, cardiac arrest, kidney stones, constipation)  ↑Threshold potential = Less excitable  1st key diagram Hyperkalemia exctabilty Hypercalcemia exctabity Hypokalemia exctability Hypocalcemia I exeltab resting threshold affects mainly affects skeletal mainly cant invest Cart 1kt KT exctabilty a  excitabilty Tear  Low SERUM K...decreased cardiac excitability  High SERUM K …increased cardiac excitability  Low SERUM Ca… increased muscle excitability  High SERUM Ca… decreased muscle excitability Sodium, Chloride & Water Regulation Primarily regulated by kidneys and hormones  Water  Hypothalamus → posterior pituitary → ADH  Na+/Cl-  Adrenal gland → Aldosterone  Atrial muscle → Natriuretic hormones  How do we balance fluids? o Image from: http://www.answers.com  Fluid TUG of WAR!!! whole body mtracellular AT Fluid Movement Between ICF and ECF Pulling forces:  Osmotic =  Nat AT  glucose V10  Oncotic =  Proteins CAPILLARY INTERSTITIAL  2 key diagram 1 interstitial interstial osmotic oncotic hydrostatic interstital space  know the why FPro cap 0 0 To d V Want Wotno Nath What symptom would What symptom would What symptom would develop from an increase in develop from an decrease develop 2 to Inflam? Cap. Hydro pressure? in Cap. O/O pressure? Edema Edema Edema What patho would cause What patho would cause Why? an increase in Cap. Hydro? an decrease in Cap. O/O? Histamine Liver disease vasodilation Hypertenstion cap perf less albumin  A Fluid Movement Between Plasma and Tissues  water, nutrients, and waste products capillary interstitial space #1 Capillary hydrostatic pressure cap Largest blood pressure = ‘fluid out’ Hydro pressure ofcapillary #2 Capillary oncotic pressure water attraction to plasma proteins = ‘fluid in’ tocapillary #3 Interstitial hydrostatic pressure Int hydro Interstitial fluid pressure = ‘fluid in’to cappilions #4 Interstitial oncotic pressure INTOT water attraction to interstitial proteins = ‘fluid out’ ofcapins  water movement normal s HTN cap Hydro 100 albumin 2 nerd Cap 010 long 10 obstruction Lymphatic 901 edema Edema!! Edema: excessive accumulation of fluids in interstitial space 4 Major Causes:  1)↑ capillary hydrostatic pressure  Venous obstruction (DVT, hepatic obstruction), salt and water retention (renal failure, HTN)  2)↓ plasma oncotic pressure o  ↓ albumin – liver disease, malnutrition, kidney disease, burns, hemorrhage 3)↑ capillary permeability – trauma, burns, neoplastic Fin  and allergic reactions tram response  4) Lymph obstruction – removal of nodes (surgery), inflammation or tumors pH  pH = power of hydrogen (0 to 14)  Inverse logarithm of the H+  pH change of 1 unit (7→6)=10x change  Biological fluids IdeatPH 7.40 pH < 7.4 = acidic > 7.4 = basic Functional Range Physiologic Range of Blood pH = 7.35 - 7.45 Absolute Range of Life: 6.8-7.8 Interchangable names  When the pH is low, it is called? PH Acidic Ht ACOS  When the pH is high, it is called? pH Bask Alkalotic Hᵗ HCO3  Body acids exist in two forms Lungs  Volatile H2CO3 (maybe eliminated as CO2)  Nonvolatile – eliminated by kidneys Ht sulfuric, phosphoric Acids  Formed as end products of protein, carbohydrate and fat metabolism it 1H05 buffer HE cg – kidneys – blood= major  Bone – lung regulatory organs Physiological pH Control Systems System Effect/Response a Fix Time not Blood Buffer Buy Respiratory QUICK FIX Metabolic/Renal Longterm FIX  Buffer is a prevents a significant change in pH  Consists of a PAIR of a weak acid and its conjugate base  Most important plasma buffering systems 1. Carbonic acid – bicarbonate system 2. Protein (Hemoglobin) Buffer Buys Time not Fix Most important buffer is a mixture of carbon dioxide (CO2) and bicarbonate (HCO3-) CO2 acts as an acid by donating hydrogen ions Forms carbonic acid when it dissolves in water H2O + CO2 → H2CO3 (carbonic acid) HCO3 is a base by soaking up hydrogen ions HCO3/CO2 buffer system is extremely important because it can be rapidly readjusted in alkalosis and acidosis Source Mayo Clinic: http://discoverysedge.mayo.edu  What are the two most important excretory systems for pH balance? CO2 Hyperventiation  1) Respiratory or Hypoventilation CO2 pre absorb back into blood  2) meatabolic kidneys 4THcost and v secrete into urine H CO2  Translation kidneys failing PH  1) Metabolic Acidosis Kidneys Faling PH  2) Metabolic Alkalosis  3) Respiratory Acidosis Lungs Failling PH  4) Respiratory Alkalosis Lungs Failing PH  3rd key Diagram Failure of… How? Symptoms Compensation Lungs are Kidneys will acidosis Hypovent202 re b.IO Holding secrete Ht Respiratory Tamatosis kidneys will reabsorb Hypervent Blowing off CO2 secrete HCO3 i 9440s's at Blow off secrete HCO metabolic It HCO alkalosis reabsorb HCO Wmst hyporent Secrete At HoldCO2 HCOS is basic  02 _Hypervent  Respiratory - ↑ or ↓ CO2 Hypovent Co2  Renal - ↑ or ↓ acidity / alkalinity of urine Reabsorb H HCO and secrete HᵗHcO3   Effects of pH on CNS  ACIDOSIS: CNS depression CNS IPA ▪ Stupor to confusion to coma Hyperkalemia  ALKYLOSIS: CNS irritability pH _MCNS ▪ Restlessness to seizures L Hypokalemia é 1) Metabolic Acidosis – Different diseases such as untreated diabetes mellitus or during starvation, the blood pH becomes acidic because there is higher carbonic acid to bicarbonate ratio. This stimulated the respiratory centers to increase respiratory rate and thus “blow off” carbon dioxide. The kidneys will also excrete increased levels of H ions and NH3. If these mechanisms can not compensate then the pathologic condition of uncompensated metabolic acidosis develops 2) Metabolic Alkalosis – Excessive use of antacids or excessive emesis can produce metabolic alkalosis. Initially the condition can result to bicarb levels up to 40 x greater than carbonic acid. Compensatory mechanisms function to increase the carbonic acid and decrease the bicarb. This is done via hypoventilation and increased renal excretion of bicarb. Once again if compensation is not adequate uncompensated metabolic alkalosis develops.  3) Respiratory Acidosis – Pneumonia, emphysema and barbiturate OD are leading causes of retention of carbon dioxide in the blood. In these conditions the carbonic acid is greater than bicarbonate buffer. The compensatory reaction is for the kidneys to excrete H ions and retain more bicarbonate. 4) Respiratory Alkalosis – Hyperventilation due to a multitude of reasons (fever or hysteria) can result in excessive loss of carbonic acid and lead to respiratory alkalosis. Once again the kidneys will attempt to compensate via increased H ion reabsorption and increased bicarbonate excretion. Source: http://www.mpoullis.net  1) Metabolic Acidosis  2) Metabolic Alkalosis  3) Respiratory Acidosis  4) Respiratory Alkalosis  ABG's Arterial Blood analysis Function Ideal set point IQ Range pH = 7.35 – 7.45 PA 7 pO2 = 80 to 100 mmHg pCO2 = 35 – 45 mmHg HCO3 = 22-26 mEq/L SaO2 = > 90% these know Forever 1. Write down ranges ee.EE 2. Setup ‘tic-tac toe’ board ftp 1. Start with pH to neararone 3. Read results, starting with pH msn.tl 1. Three parts in total all in f Column Organ system pH analysis Compensation w foll comp Respiratory Acidosis w Partial Comp metabolic alkalosis no comp w  Acids Bases Patient 1 7.35 7.45 PH pH = 7.3 mong pCO2 = 40 mmHg zz amea HCO3 = 20 mEq/L metabolic Acidosis w no comp pFfI aÉos  Patient 2 PA 7.35 7.45 coz 215 35  pH = 7.50 Dying G  Pco2 = 27mm Hg HC03 22 26  HCO3 = 14mEq/L FEE 4605 Respiratory Alkalosis w partial comp  Patient 3 PH 7.35 7 45 35 a 45 20  pH = 7.37 HC03 22  Pco2 = 30mm Hg  HCO3 = 14mEq/L F comp metabolliacidosis w full HCU