Question | Answer |
Intracellular fluid | within the cells |
Extracellular fluid | Intravascular fluid: blood and lymph system. Interstitial fluid: between cells. Transcellular: cerebrospinal, pleural, peritoneal, synovial |
Osmolarity:mOsm/L | the proportion of dissolved particles (solute) in a volume of fluid. |
Osmolarity:mOsm/Kg | Concentration of dissolved substances in a given weight of fluid (rather than a given volume) |
Electrolytes in intracellular fluid | Potassium K+, Phosphorus PO4-, Sulfate SO4- |
Electrolytes in extracellular fluid | Sodium Na+, Chloride Cl-, Bicarbonate HCO3- |
Sodium Na+ | 90% in ECF. Major contributor to maintaining water balance. Normal serum value 135-145 mEq/L |
Potassium K+ | Mostly in ICF. Essential for normal cardiac, neural, and muscle function. Normal serum value: 3.5-5.0 mEq/L |
Magnesium Mg++ | 50-60% in bones. Important in regulating neuromuscular function and cardiac activity. Normal serum value: 1.5-2.5 mEq/L |
Calcium Ca+ | 99% in bones and teeth. 50% ionized, 50% bound to proteins. Normal serum value: 4.5-5.5 mEq/L or 8.5-10.2 mg/dL |
Hypocalcemia | Net loss of Ca+ from extracellular fluid in greater quantities than can be replaced by intestines or bones. Clinical manifestations are increase excitability of muscles and nerves. |
Chvosteks Sign | Tapping on facial nerve just anterior to ear produces tetany (involuntary twitching on the ipsilateral (same) side of the patients face/upper lip) due to hypocalcemia |
Trousseau Sign | Inflate a BP cuff above NSBP range. Positive response in a patient with hypocalcemia is a wrist, metacarpal and phalangeal/thumb flexion |
Chloride Cl- | ECF, transport follows sodium. Normal serum value: 95-105 mEq/L |
Bicarbonate HCO3- | Major chemical buffer. Normal serum:19-25 mEq/L Normal Arterial: 22-26 mEq/L |
Phosphorus PO4- | 85% in bones. Normal serum value: 2.4-4.7 mg/dL |
Diffusion | Movement of a solute from area of higher solute concentration to area of lower solute concentration until equally distributed. O2 & CO2 exchange in pulmonary capillaries and alveoli |
Osmosis | Movement of water through a semipermeable membrane from an area of lesser solute concentrate (hypoosmolar) to an area of greater solute concentrate (hyperosmolar) to equalize) |
Active transport | Movement of ions "uphill" from area of lesser concentration to area of greater concentration. Requires energy. Sodium potassium pump. |
Filtration | transfer of water & dissolved substances through a permeable membrane from a region of high pressure to a region of low pressure. Glomerular filtration. |
Glomerular filtration | The first step in urine formation. |
Pressures affecting fluid and electrolyte movement | Osmotic pressure and tonicity: hypertonic, isotonic, Hypotonic. Hydrostatic pressure. Filtration pressure. |
Isotonic deficit and excess | Extracellular fluid volume deficit. Extracellular fluid volume excess. |
Water or osmolar imbalance | Water deficit or hyperosmolarity. Water excess or hypoosmolarity. |
Third Space | Areas (spaces) in which fluid can collect that is not available to the circulation, or the process of the fluid shift into such spaces.Third space fluid shifting, is the movement of fluid from inside the blood vessels into the interstitial space. |
Normal Acid-Base Balance | Optimal function of cells requires a steady balance between acids and bases. Balance between carbon dioxide (CO2) which is regulated by lungs and bicarbonate (HCO3-) which is regulated by the kidneys. |
Arterial Blood Gases | ABG analysis: best way to evaluate acid-base balance. pH: 7.35-7.45, PCO2: 35-45 mm Hg, PO2: 75-100 mm Hg, HCO3-: 22-26 mEq/L, Oxygen saturation: 96-100% |
pH | Normal: 7.35-7.45, Acidosis: <7.35, Alkalosis: >7.45, Normal pH exists when there is a stable concentration of hydrogen ions. |
Assess the pCO2 | Normal 35-45 mm Hg, Resp acidosis: >45, Resp alkalois: <35 |
Assess the HCO3- | Normal:22-26 mEq/L. Met Acidosis <22. Met Alkalosis >26. |
Important rule regarding abnormal ABGs | With two abnormal values, physiologically, there MUST be an inverse relationship between the pH and pCO2 (increase in H+ ion) in order for it to be respiratory! If there is NO inverse relationship, it is metabolic. |
No compensation: | If one component (pCO2 or HCO3) is abnormal and the other one is normal. |
Partially compensated: | If both pCO2 and HCO3 are abnormal and the pH is NOT normal |
Totally compensated: | if both pCO2 and HCO3 are abnormal and the pH is within normal range. |
Compensation | Respiratory compensation reacts to metabolic imbalances. Reacts quickly. Renal compensation reacts to respiratory imbalances. Hours to days. |
Respiratory Acidosis | a condition that occurs when the lungs cannot remove all of the carbon dioxide the body produces. This causes body fluids, especially the blood, to become too acidic. |
Metabolic acidosis | a condition that occurs when the body produces too much acid or when the kidneys are not removing enough acid from the body. If unchecked, metabolic acidosis leads to acidemia, i.e., blood pH is low.consequences can be serious, including coma and death |
Respiratory alkalosis | a condition marked by low levels of carbon dioxide in the blood due to breathing excessively |
Metabolic alkalosis | condition in which the pH of tissue is elevated beyond the normal range ( 7.35-7.45 ). This is the result of decreased hydrogen ion concentration, leading to increased bicarbonate, or alternatively a direct result of increased bicarbonate concentrations |
Acid-base Imbalances | Each imbalance can be uncompensated, partially compensated, or compensated |
Fluid and food intake | Regulated by thirst. Intake 2.0-2.5 L/day: Ingested liquids, water in foods, water from metabolism |
Four organs of loss | Kidneys as urine: Normal output ~1500ml/day. Minimum of 30 ml/hr.
Skin as perspiration. GI tract as stool or vomit. Lungs as insensible water loss |
Factors affecting Fluid, Electrolyte, and Acid-base Balance | Stress, age, surgery, pregnancy, Chronic illness: renal failure, cardiac failure, liver failure, respiratory failure |
Assessment | History of acute and chronic illnesses. Risk factors: age, lifestyle, diet, medications. Intake and output. Body weight |
Assessment cont'd | Vital signs: respiratory rate and depth, heart rate and rhythm, postural pulse rate & BP. Skin turgor. Neck veins. Peripheral edema. Elimination:Bowel, Urinary. Mental status. Muscle tone. Changes in ADLs |
Laboratory and Diagnostic Tests | CBC, serum electrolytes, plasma osmolarity, urine osmolarity, urine specific gravity, arterial blood gases. |
Nursing Diagnosis | Deficient or excess fluid volume. Imbalanced nutrition. Constipation. Diarrhea. Impaired gas exchange. Ineffective tissue perfusion. Ineffective breathing pattern. |
Outcome Identification and Planning | Client goals: Client will reestablish normal electrolyte balance on day 1 by verbally reporting two foods high in potassium. Client will demonstrate knowledge regarding how to prevent future electrolyte imbalances by discharge. |
Implementation | I&O Daily weight. Diet & oral fluids. |
Parenteral replacement of F | Hypotonic solutions (0.25% NS, 0.45% NS) Solute concentration less than cell/fluid moves into cell. Isotonic solutions (0.9% NS, Lactated Ringers) homeostasis achieved equal solute. Isotonic bit physiologically hypotonic (5% Dextrose in water D%W) |
Hypertonic Solutions | (10% Dextrose in water, 3% Saline, 5% Dextrose in 0.9% Saline Dextrose 10, TPN) Solute concentration greater than cell/fluid moves out of cell. |
Patient education | Dietary sources for electrolytes. Fluid restrictions. Medications: Meds for underlying diseases, electrolyte replacement. Signs and symptoms of fluid, electrolyte and acid-base imbalances. |
Evaluation | Evaluate client outcomes and goals. Goal met clients weight at goal of 143 lbs upon discharge. Goal not met. client has not verbalized understanding of which foods contain potassium. |