Fluid and Electrolytes

normal sodium135-145 mEq/L
normal potassium3.5-5 mEq/L
normal BUN7-20 mg/dl
normal hematocrit40-50%
normal urine specific gravity1.002-1.030
normal glucose60-110 mg/dl
normal osmolality


FVD classic signdry mucous membranes, comes later
FVD late signhypotension
FVD, temp changesdecreased temp, blood shunted to central area
FVD, respiratoryincreased respiratory rate bc acidotic, blowing of CO2; thick and sticky secretions
anasarcasevere, generalized third spacing
most common site, 3rd spacingabdomen (ascites, in peritoneal cavity?)
primary mediator of fluidshypothalamus
2nd spacingstage where fluid moves from one space to another
3rd spacingfluid in interstitial compartments
FVD sodiumnormal to high (hemoconcentration)
FVD potassiumnormal to high (is intracellular, if enough cell death --or sodium levels -- could be high)
FVD BUNhigh (hemoconcentration); in children may be low but not pathologic
FVD glucosenormal to high (stress response, >120)
FVD urine specific gravityhigh >1.030
FVD osmolality (serum)>300, more particles ↑ number of particles, concentration
FVE hemodynamic signsfull bounding pulses, hypertension, increased CVP, neck vein distension, CHF
cerebral edemaseen with FVE, Confusion, dizziness, convulsions, coma
pulmonary edemaseen with FVE, Dyspnea, tachypnea, hacking cough, crackles, o2 sat down
FVE general signsweight gain, nonpitting interstitial edema, hepatomegaly/splenomegaly
FVE first sign seenpulmonary edema
neck vein distensionsign of FVE but not seen in kids, make sure know baseline for adults
goal of Rx for FVEprevent cerebral edema
>>> causes of FVE (10)renal failure, heart failure, excess fluid intake (without electrolytes), high corticosteroids, high aldosterone, plain water enema, NG irrigations, excess hypotonic IV fluids, SIADH, inappropriately prepared formula (dilute formula)
>>> excess fluid intake examplesexcessive hypertonic fluids, binge drinking contest, psych disorders, drowning in fresh water, inappropriate dialysis
FVE, potassiumnormal to high (potassium shift out of cells, rasing levels)
FVE, sodiumvery low, <125
FVE, BUNlow (hemodilution)
FVE, urine spec gravitylow, <1.005
FVE, glucosenormal to high (stress response, >120)
decreased sodium and potassium signslethargy, weakness
increased sodium and potassium signsincreased excitability
acidreleases H+ ions in water
basebinds to H+ ions in water
buffersprevent major acid-base changes; carbonic acid-bicarbonate, protien, and phosphate buffer system
carbonic acidmeasured as CO2
acid-base homeostasisbicarb: carbonic acid = 20:1
carbonic acid-bicarb systemprimary system, 50% of activity, to maintain balance l/t have to also use protein and phosphate buffer systems, 1-2 hours to kick in, bicarb is the major ECF buffer
alkaline environmenthard for cells to grow
>>> Respiratory buffer system, carbonic acidcarbonic acid compensates and dissociates into CO2 and H20, CO2 exhaled by lungs, system activates rapidly but exhausted quickly
respiratory buffer system, breathing changeschanges in depth/rate of resp alters it: hypoventilation retains CO2/carbonic acid and causes acidosis, hyperventilation loses CO2 and causes alkalosis
renal buffer system: time and effectivenessworks w/in hours/days, more efficient than respiratory can go for longer periods of time
renal buffering system, bicarbonateprimary renal component, can be absobed as needed, combines HCl with ammonia to make ammonium, which is easily excreted by kidneys into urine
compensationregulatory mechanism to return pH to normal level by transforming acids and bases within the body
primary metabolic disturbancecauses a respiratory compensation
acute primary respiratory disturbancecauses an acute metabolic response
complete compensationpH is fully corrected (normal)
partial compensationbuffers are in the process of working; pH is low but the bicarb is elevating to compensate (or pH is high but CO2 is elevating to compensate)
pH*negative logarithm of H+ ion concentration in mEq/L (as H+ ion concentration increases, pH decreases) *normal values 7.35 -7.45 (less is acidotic, more is alkalotic)
HCO3- (bicarb)*normal 22-26 mEq/L (decreased in acidosis, increased in alkalosis)
BE "base excess"indicates the amount of bicarb available in the ECF normal value: +/- 2 mEq/L
serum anion gap*Concentration of anions (HCO3- , Cl-, protein, phosphate, & sulfates) and cations (Na+, K+, MG++, & Ca++) *10-12 mEq/L normal *increased in metabolic acidosis (but can be normal) *calculated by Na - Cl + bicarb
SaO2the percent of Hb saturated with O2, a calculated value (indirect measurement), calculated with pH and PaO2 (combination of O2 sat, PaO2, and Hb), indicates tissue oxygenation
PaO2amount of oxygen available to bind with hemoglobin, amount of pressure exerted on O2 by plasma
the lower teh PaO2 pressure, the ....less oxygen available to bind with Hb
dramatic drops in PaO2correlate with dramatic drops in oxygen saturation
PaO2 normal values75-100 mmHg (for every year above 60 drop 1mmHg)
PaCO2*partial pressure of CO2 *reflects adequacy of alveolar ventilation, regulated by lungs, alterations indicate resp disturbance *normal values 35-45 mmHg (less is alkalotic, more is acidotic)
respiratory alkalosis managment (4)correct cause, rebreathe CO2 as needed, alter ventilation rate, sedatives (for anxiety)
respiratory alkalosis assessment (7)VS, ABGs, RR/depth, LOC/anxiety, neuro checks, injury potential, I&O
respiratory alkalosis CV signstachycardia, palpitations, increased myocardial irritability
respiratory alkalosis respiratory signsrapid shallow breathing (trying to retain CO2, oxygenate), chest tightness
respiratory alkalosos CNS signs (10)paresthesia, dizzyness, confusion, tetany, convulsion, numb/tingling, light headed, anxiety/panic, Loss of consciousness, hyperactive reflexes
respiratory alkalosis causes (4)hyperventilation, sepsis/infection, over ventilation, hepatic cirrhosis
respiratory alkalosis: labslow CO2, pH high >7.45, bicarb normal if no compensation or decreased if compensation, hypokalemia, hypocalcemia
respiratory acidosis management (7)correct cause, CPT, TCDB if able, suction as needed, semi-Fowlers, fluids to thin secretions, low-flow O2 as needed
respiratory acidosis assessment (8)VS, ABGs, RR/depth, apical pulse, LOC, EKG, skin color/nail beds/mucous membranes, I&O
respiratory acidosis cardiac signshypotension, peripheral vasodilation weak thready pulse, tachycardia, warm flushed skin
respiratory acidosis respiratory signsdyspnea, slow shallow respirations, hypoxia and hypoventilation, cyanosis
respiratory acidosis CNS signs (6)HA, seizures, altered LOC, papilledema, twitching/tremors, drowsy --> coma
respiratory acidosis causes (4)respiratory depression/arrest, inadequate chest expansion, airway obstruction, interference with alveolar capillary exchange
respiratory acidosis: labspH low <7.35, PaCO2 high >42, HCO3- normal (or elevated with compensation), hyperkalemia
metabolic alkalosis mgmnt (3)correct cause, restore normal fluid balance, adequate chloride (enhance renal absorption of sodium and excretion of bicarb)
metabolic alkalosis assessment (6)VS, ABGs, RR/depth, LOC, I&O, ECG
metabolic alkalosis GI signs (3)n/v, anorexia, paralitic ileus (hypokalemia)
metabolic alkalosis CNS signs (10)dizzy, nervous, tremors, hyperreflexia, paresthesias, irritability, confusion/apathy/stupor, cramps, tetany, seizures
met alkalosis respiratory signs (2)hypoventilation, respiratory failure
met alkalosis CV signs (5)tachycardia, HTN, PVC, atrial tachycardia, dysthrythmias (from FVE)
met alkalosis causes (4)vomiting, NG suctioning, eating bicarb-based antacids, diuretics
met alkalosis: labsincreased pH, increased BE, increased bicarb, decreased anion gap (low K and Na)
met acidosis mgmnt (6)correct cause, treat ketoacidosis (fluids, insulin), give alkaline fluids, hydrate, mechanical ventilation if needed, possible dialysis
insulinused to treat metabolic acidosis (ketoacidosis), forces potassium back into cells
alkaline fluids for met acidosisif severe, sodium bicarb if pH<7.20, salts of organic acid (lactate, citrate), tromethamine THAM
met acidosis assessment (7)VS, ABGs, RR/depth, apical and peripheral pulses, ECG (bc of dramatic K changes), LOC, I&O
metabolic acidosis CV signs (4)dramatic affects: hypotension, dysrhythmias, peripheral vasodilation, warm flushed skin (from dilation, leaking of capillaries)
metabolic acidosis resp signsKussmaul/deep/rapid respirations, trying to blow off CO2
metabolic acidosis CNS signs (6)think of septic patient: drowsy, HA (from cerebral edema), lethargy, coma, confusion/restless, weakness
metabolic acidosis GI signs (3)n/v, diarrhea, abdominal pain
causes of metabolic acidosischronic diarrhea, malnutrition, starvation, renal failure, DKA, trauma, shock, sepsis, fever, salicylate toxicity
metabolic acidosis: labslow bicarb, decreased BE, increased anion gap, hyperkalemia (from breakdown of cells from acidosis), high metabolic acids (lactic acids, ketoacids)

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