Fluid, Electrolyte, & Acid-Base Balance

7.35-7.45

normal range for pH

35-45

normal range for pCO2

75-100

normal range for pO2

22-26

normal range for HCO3-

greater than 95%

normal O2 stat (slightly different than our norm)

acidosis

a low pH is considered…

alkalosis

a high pH is considered…

aklalosis

a low pCO2 is considered…

acidosis

a high pCO2 is considered…

acidosis

a low HCO3 is considered…

alkalosis

a high HCO3 is considered…

metabolic acidosis

pH is low, HCO3 is low

metabolic alkalosis

pH is high, HCO3 is high

respiratory acidosis

pH is low, CO2 is high

respiratory alkalosis

pH is high, CO2 is low

death

abnormal pH can lead to

respiratory

which regulatory method for acid-base balance can act quickly (minutes to hours)

renal

which regulatory method for acid-base balance is a slower compensatory mechanism? (up to 3 days)

arterial blood gases/venous blood gases

acid-base balance is measured through what?

partial pressure

______ ______ of the gases reflect the overall effectiveness of gas exchange

venous blood gases

which method for measuring acid-base balance is less painful

fully compensated

normal pH but abnormal pCO2 or HCO3

partially compensated

all 3 (pH, pCO3, and HCO3) abnormal

uncomponsated

pH and one other (pCO3, HCO3) abnormal

kussmaul breathing, flushed skin, dehydration, abdominal pain, N/V

S/sx of metabolic acidosis (5)

severe infection, diabetic acidosis, tissue trauma, shock, renal failure, heart failure, severe diarrhea or starvation

causes of metabolic acidosis (8)

shallow breathing, tetany-like symptoms, confusion, irritability, vomiting

s/sx of metabolic alkalosis (5)

hyperemesis, gastric suctioning, peptic ulcers

causes of metabolic alkalosis (3)

dyspnea/impaired gas exchange, flushing/warm skin, tachycardia/weakness

s/sx of respiratory acidosis (3)

pneumonia, COPD, chest injuries, opioids

causes of respiratory acidosis (4)

rapid shallow breathing, tetany-like symptoms, palopitations/vertigo

s/sx of respiratory alkalosis (3)

fever, pain, brain tumor, anxiety, drug toxicity, excessive exercise

causes of respiratory alkalosis (6)

respiratory rate and depth

how do the lungs regulate acid balance with CO2

short

is respiratory management of acid base long or short term?

H+ and HCO3- balance

how do the kidneys balance acid-base?

up to 3 days

how long does renal regulation take to correct pH?

respiratory rate and depth, cognitive function, and dizziness

things to assess for acid base other than lab values

intracellular fluid

this is critical for maintaining cell size

70%

ICF is __% of total body fluid

40%

___% of adult body weight is from ICF

30%

___% of total body fluid is ECF

20%

ECF is ___% of body weight

intravascular fluid, interstitial fluid, trans cellular fluid

what are the 3 parts of extracellular fluid?

intravascular fluid

plasma of the blood, blood volume, impacts HR/BP

interstitial fluid

surrounds cells

trans cellular fluid

cerebrospinal, pleural, peritoneal, synovial, digestive secretions, sweat, etc.

osmolarity

concentration of particles in a solution (or its pulling power)

isotonic

when the osmolarity is equivalent to plasma; remains in the intravascular space

hypertonic

when the osmolarity is greater than plasma; pull water from cells into the intravascular space

hypotonic

when the osmolarity is less than plasma; more from intravascular space to the ICF

Normal Saline and Lactated Ringers

what are two isotonic solutions?

normal saline

expand the extracellular compartment, treat hypovolemia, hyponatremia, hypercalcemia, and metabolic alkalosis

lactated ringers

contains multiple electrolytes in the same concentration as in plasma (lacks magnesium); treats hypovolemia, burns, and GI losses

5% Dextrose in LR (D5LR)

replaces electrolytes, provides calories, shifts fluid from cells to vascular space expanding vascular volume

D5LR

example of a hypertonic solution

half strength NS

example of a hypotonic solution

half strength NS

often used as a maintenance fluid, provides NA, CL, and free water

True

True or False: perfect fluid balance is not always met every day, but over 2-3 days

sensible output

output that is measurable; urine, emesis, stool, blood

insensible output

output that isn’t measurable; sweat and tears

wt, ht, temp

the formula for insensible output uses what 3 things?

kidneys, heart/vascular, lungs, nervous, GI

what organ systems help manage the fluid and electrolyte balance? (5)

1.5 L

the kidney produces how much urine a day?

180 L

the kidney filters how much plasma a day?

ECF volume and osmolality

what part of fluid balance does the kidney manage? (2)

circulate fluid, adequate perfusion, pressure in kidneys for filtration, stretch receptors stimulate fluid retention when hypovolemia detected

how does the heart regulate fluid and electrolytes? (4)

thirst center in hypothalamus, osmoreceptors sense changes in ECF concentration and stimulate the pituitary gland to release or inhibit ADH

how does the NS regulate fluid/electrolyte balance? (2)

adrenal, pituitary, thyroid, and parathyroid

what glands help with hormonal control of fluid and electrolyte balance? (4)

adrenal glands

supports blood volume by secreting aldosterone which causes sodium and water retention and potassium loss

cortisol

excessive _______ secretion can cause the same effect as aldosterone

pituitary gland

manages ADH, which allows the body to retain water

increased

when the osmotic pressure of ECF is greater than that of the cells or when blood volume is decreased does ADH increase or decrease?

decrease

when osmotic pressure of the ECF is less than that of the cells, or when blood volume is increased does ADH increase or decrease

thyroid gland

increases blood flow to the kidneys to increase filtration rate and output

parathyroid gland

regulates calcium and phosphate balance

PTH

this hormone influences bone reabsorbtion, calcium absorption from the intestines and calcium reabsorption from the kidneys

increased; decreased

increased PTH causes ______ blood (serum) calcium and _______ phosphate

decreased; increased

decreased PTH causes ________ calcium and _______ phosphate

liver dysfunction

ascites is typically caused by…

fluid volume deficit/hypovolemia

loss of fluid and solutes from ECF

dehydration

loss of total body water, results in increased serum sodium

fluid volume excess

retaining sodium and water in ECF

hypervolemia

intravascular fluid volume excess

edema

interstitial fluid volume excess

third spacing

fluid moves into transcellular compartments (pleural, peritoneal, pericardial, joints, bowel) or interstitial spaces; causes hypovolemia because fluid is unavailable

third spacing

fluid distribution problem (1)

fluid volume deficit/hypovolemia, dehydration, fluid volume excess

fluid volume problems (3)

electrolytes

the basis for chemical interactions in the body necessary for metabolism and other functions

Na+, K+, Ca+, H+, Mg+

list the cation electrolytes (5)

Cl-, HCO3-, PO4-

list the anion electrolytes (3)

-netremia

sodium root

-kalemia

potassium root

-calcemia

calcium root

-magnesemia

magnesium root

-phosphatemia

phosphorus root

-chloremia

chloride root

135-145

normal range for sodium

diuretics, GI losses, excessive water intake

causes of hyponatremia (3)

confusion, lethargy, twitching, seizures, coma

what are the major symptoms for hyponatremia? (5)

I&O, encourage sodium rich foods, seizure precautions, careful IV replacement

treatment for hyponatremia (4)