Unit 6

• Fluid/Electrolyte
• Acid/Base

• Intracellular-inside the cells
• Extracellular-all fluids outside the cells
• -Interstitial-around the cells
• -Intravascular-in the blood stream
• -Transcellular-fluids seperated from other fluids by a cellular barrier

• An electrolyte or compound, that when dissolved or dissociated in water or another solvent, seperates into ions that are electrically charged
• Cations-sodium Na+, potassium K+, Calcium Ca+
• Anions-chloride Cl-, Bicarbonate HCO3-, Sulfate

• Solvent-the solution in which a solute is dissolved (water)
• Solute-electrolyte or item that is dissolved (glucose, proteins)

• Osmosis is movement of a solvent across a semipermeable membrane into a region of a higher concentration
• Rate is dependent upon
• 1. concentration of the solutes in the solution
• 2. temperature of the solution
• 3. electrical charges of the solutes
• 4. differences b/t osmotic pressures exerted by the solutions
• 5. tonicity of solution

• Hypertonic-solution of higher osmotic pressure, pulls fluid from cells causing them to shrink
• Hypotonic-solution of lower osmotic pressure, moves fluid into the cells causing them to enlarge

• Diffusion-solute moves across a semipermeable membrane from high concentration to low concentration
• Filtration-movement of solvent and solute particles across a membrane, driver is pressure (high to low)
• Active transport-transport of substances across cell membranes, allows cells to admit larger molecules that they would otherwise would not be able to admit, lesser concentration to higher concentration

• Thirst mechanism in the hypothalamus
• Osmoreceptors monitor the serum osmotic pressure, when osmolality increases the hypothalamus is stimulated

• Pituitary gland
• hypothalamus
• kidney/adrenal glands
• heart

• Kindeys-produce a minimum of 0.5 ml/kg/hr
• Lungs-expire about 500 ml of water daily

• The largest chemical buffer in the ECF is the carbonic acid and bicarb buffer system
• First buffering system to react to change in pH of ECF and it reacts within seconds

• Occurs after chemical buffering
• Buffering occurs when H+ ions are absorbed or released by cells
• RBC's the prime cells

• Lungs regulate respiration speed to increase or decrease levels of CO2 in the blood-Response time is seconds to minutes
• Kidneys increase of decrease levels of many different ions in blood through excretion or blocked filtration, kidneys reabsorb bicarb incases of acid excess and excrete it in cases of acid deficit-Response time is hours to days

• Can occur with net sodium loss or net water excess
• Caused by vomiting, diarrhea, NG suctioning, burns, excessive sweating
• Signs & symtoms: apprehension, postural hypotension, dizziness, N/V, tachycardia, dry mucous membranes
• Associated with changes in volume status, altered thirst mechanism, med side effect
• Fluid overload is most common cause

• Caused by excess salt intake, excess aldosterone secretion, diabetes, water deprivation
• From renal or extrarenal cuases such as GI or skin problems.
• Water moves to maintain balance when sodium levels increase, osmotic shift of water from cells to ECF creates cellular dehydration.
• S/S: weakness, N/V, agitation, irritability, kidneys excrete some of the eccess water, skin becomes flushed, dry, thirst, fever, hypotension, confusion, dysrhythmias
• Treat by restoring cell volume by decreasing the ratio of sodium to water in the ECF

• Decreased funtion of the muscles and nerve impulses conduction, can lead to cardiac arrest.
• Etiologies: diuretics, malnutrition, starvation, anorexia, NPO status, GI losses, increased aldosterone, corticosteroids, metabolic alkalosis
• Treatment: ECG, VS, potassium chloride, oral replacement, foods high in K+.  IV replacement alwayus on pump, dilute, never IV push

• Seldom occurs in healthy people, most serious of all electrolyte imbalance
• Manifestations: peaked T wave, bradycardia, cardiac arrest, hyperreflexia, muscle twitches, numbness, paralysis, increased peristalsis, abdominal cramping, diarrhea, oliguria
• Etiologies:
• Decreased Potassium Excretion-renal failure, adrenal insufficiency, potassium sparing diuretics, ACE inhibitors
• Potassium Excess: excessive salt intake, potassium supplements, IV potassium infusions
• Shift of potassium out of cells:  cell destruction (trauma, burns, chemo, radiation), metabolic acidosis, lack of insulin, transfusion of old blood products
• Treatment: EKG, potassium restrictions, decrease levels safely, insulin and glucose IV, kayexalate and lactulose, diuretics

• Anxiety, irritability, bradycardia, hypotension, EKG changes, stridor, increased peristalsis, diarrhea, hyperreflexes, seizures, convulsions, tetany, positive Trousseau's sign and Chvostek.
• Etiology: latose intolerance, anorexia, alcoholism, Vit D deficiency, inadequate UV light, reanl failure, pancreatitis, laxatives, antacid overuse, malabsorption disorders, long term steroid use, Lasix, blood transfusions
• Treatment: find underlying cause and correct it, cardiac monitoring, IV Calcium gluconate, reassess labs

• confusion, lethargy, coma, bradycardia, EKG changes, hyporeflexia, bone pain, fractures, polyuria, decreased clotting time.
• Treatment: cardiac monitoring, IV NS, push PO fluids, loop diuretics, low calcium, weight bearing exercies, hemodialysis

• Memory loss, disorientation, hallucinations, dysrhythmias, EKG changes, hyperreflexia, tremors, seizures
• Etiologies: malnutrition, alcoholism, TPN without magnesium, diuretics, N/V/D, GI suction, laxative use
• Treatment: stop dig, patients on TPN need magnesium, assessment, correct imbalance in a safe manner, diet high in magnesium
• Treatment: Mag sulfate IV, urine outut must be at leaset 30 ml, monitor DTR's, respiratory status, Calcium gluconate IV,

• Decreases neuromuscular excitability, from renal failure,
• Manifestations: lethargy, drowsiness, coma, dysrhythmias, hypotension, respiratory depression
• Etiologies: renal failure, IV mag replacement, Mag treatmenf in preeclampsia of pregnancy
• Treatment: monitor at risk, IV NS to dilute serum magnesium, loop diuretics, calcium gluconate IV, dialysis

• 1 gram = 1ml
• 1 year old: 1ml/kg/hr
• Infants: 2 ml/kg/hr

Fluid needs increase by 7 ml/kig/day for every degree above 99 degrees.

GI fluid loss, diarrhea (rotovirus), vomiting (curdled food=gastric problems, bilious, green= bowel blockage)

• Thirsty <3% fluid deficit
• Dryness of mucous membranes 3-10%
• Marked tachycardia, oliguria, loss of skin elasticity, somnolence >10%

decreased BP, increased HR, sunken eyes, decreased urine, change in respirations, arrhythmias, confusion, weakness

Degree of dehydration, signs and symptoms, rehydrate, replace stool loss, maintenance

• Daily mainenance fluid requirements: amount needed to provide fluid in a child who is NPO or has fluid intake but hasnot/is not experiencing abnormal fluid losses
• Replacement requirements: amount needed to make up for fluid losses

• 1-10 kg _____ml/kg/day
• 11-20 kg above + ______ml/kg/day
• 21kg and over above +_______ml/kg/day