Week 1: Lab values and interpretation-Fluid Balance

Fluid balance

volume and distribution of body fluids that vary between bodies

how much of adult body weight is water

45-60%

1/3 of BW is

extracellular fluids (volume is measured)

2/3 of BW is

intracellular fluids (volume inferred)

amount of water entering body should =

amount leaving

intake

solid foods and fluids

output

urine and feces, small amounts through skin and exhaled air

hypothalamus function fluid balance

thirst mechanism, osmoreceptors cells sense fluid volume and turn into thirst mechanism when fluids are needed

antidiuretic hormone is produced by the

pituitary gland

ADH function in fluid balance

promotes reabsorption of water into blood in kidney tubules

Aldosterone is produced by the

adrenal gland

aldosterone function in fluid balance

determines reabsorption of Na+ and H2O from tubules, conserve more fluid when there is fluid deficit

Cardiac Hormones (ANP and BNP)

respond to increased intrachamber pressure and stimulate H2O elimination

2 types of fluid deficits

dehydration and hypovelomia

dehydration

excessive loss of body water or inadequate intake

reasons for dehydration

diarrhea, vomiting, diaphoresis

hypovolemia

decreased blood and plasma volume

reasons for hypovolemia

bleeding/trauma, loss of plasma (burns)

2 types of fluid excess

edema, hypervolemia

edema

excessive fluid in interstitial spaces or body cavities

reasons for edema

renal disease, heart failure

hypervolemia

excess fluid within blood vessels

dehydration effects on head/neck

thirst, dry mucous membranes, lethargy/confusion

dehydration effects on extremities

mm weakness, tingling

dehydration effects on skin

dry, decreased turgor

decreased turgor means

remains elevated after being pulled up and released

dehydration effects on respiration

changes in rate/depth of breathing sounds

dehydration effects on circulation

pulse rate irregularities, arrhythmias, postural hypotension, tachycardia

dehydration effects on abdomen

abdominal cramps

edema effects on head/neck

distended neck veins, facial edema

edema effects on extremities

dependent pitting edema

edema effects on skin

warm, moist, taut, cool feeling when edematou

edema effects on respiration

dyspnea, orthopnea, productive cough

edema effects on circulation

hypertension, distended neck veins, bounding pulse, atrial arrhythmias

edema effects on abdomen

increased girth

implications for Pt and dehydration

push oral fluids, check urine (if dark or less), check BP

implications for Pt and edema

dependent areas first, inspect skin, adhere to fluid restrictions

where is edema if sitting

LE

where is edema if supine

sacrum

what tissue is more prone to skin tears

edematous because its stretched and has limited blood supply