CHAPTER 57 - FLUID IMBALANCES Flashcards
CHAPTER 57
Fluid Imbalances
Body fluids are distributed between
intracellular fluid (ICF) and extracellular fluid (ECF) compartments.
ICF lies within
MAKES UP HOW MUCH OF TOTAL BODY FLUIDS IN ADULTS
body cells and constitutes two-thirds of the total body fluids in adults.
ECF is comprised of
intravascular, interstitial, lymph, transcellular fluids
PLASMA
intravascular FLUID
INTERSTITIAL FLUID
fluid that surrounds the cells
transcellular fluids
cerebrospinal,
pericardial,
pancreatic,
pleural,
intraocular,
biliary,
peritoneal,
synovial fluids
Fluid can move between
compartments (through selectively permeable membranes) by a variety of methods in order to maintain homeostasis.
METHODS FLUID CAN MOVE BETWEEN COMPARTMENTS
(diffusion, active transport, filtration, osmosis)
Fluid imbalances that the nurse should be familiar with are fluid volume deficit and fluid volume excess.
fluid volume deficit and fluid volume excess.
FLUID VOLUME DEFITICT (FVD)
or isotonic dehydration, is a lack of both water and electrolytes, causing a decrease in circulating blood volume. This is also called fluid volume deficit (FVD).
AKA - Hypovolemia
FLUID VOLUME EXCESS (FVE)
Excess fluid volume, fluid overload, and fluid or water retention are all phrases to describe the medical term, hypervolemia. Hypervolemia iswhen the body has too much fluid. Fluid overload occurs when the body can’t get rid of fluid or holds onto it (retention) usually caused by excess sodium
Dehydration
is a lack of fluid in the body, from insufficient intake or excessive loss.
◯
Actual dehydration
is a lack of fluid in the body;
relative dehydration
involves a shift of water from the plasma (blood) to the interstitial space.
◯
Hypovolemia, AKA
or isotonic dehydration, is a lack of both water and electrolytes, causing a decrease in circulating blood volume. This is also called fluid volume deficit (FVD).
● Compensatory mechanisms include
sympathetic nervous system responses
sympathetic nervous system responses INCLUDE
of increased thirst, antidiuretic hormone (ADH) release, and aldosterone release.
● Rapid or severe dehydration can induce
● Rapid or severe dehydration can induce seizures.
● FVD can lead to
hypovolemic shock.
● Older adults have an increased risk for dehydration due to multiple physiological factors including
a decrease in total body mass, which includes total body water content
a decrease in the ability to detect thirst.
CAUSES OF ISOTONIC FVD (HYPOVOLEMIA)
Excessive gastrointestinal (GI) loss:
● Excessive skin loss:
● Excessive renal system losses:
● Third spacing:
● Hemorrhage
● Altered intake:
Excessive gastrointestinal (GI) loss:
vomiting, nasogastric suctioning, diarrhea
● Excessive skin loss:
diaphoresis without water and sodium replacement
● Excessive renal system losses:
diuretic therapy, kidney disease, adrenal insufficiency
● Third spacing:
burns
● Hemorrhage or
plasma loss
● Altered intake:
anorexia, nausea, impaired swallowing, confusion, nothing by mouth (NPO) (decreased intake of water and sodium)
NPO
(decreased intake of water and sodium)
CAUSES OF DEHYDRATION
Hyperventilation / excessive perspiration w/out water replacement
● Prolonged fever
● Diabetic ketoacidosis
● Insufficient water intake
● Diabetes insipidus
● Osmotic diuresis
● Excessive intake of salt, salt tablets, or hypertonic IV fluids
POSSIBLE REASONS FOR Insufficient water intake
(enteral feeding without water administration, decreased thirst sensation, aphasia)
DEHYDRATION EXPECTED FINDINGS
VITAL SIGNS: ALTERATIONS
NEUROMUSCULOSKELETAL ALTERATIONS
GI ALTERATIONS
RENAL ALTERATIONS
OTHER ALTERATIONS
VITAL SIGNS: - DEHYDRATION
Hypothermia (hypovolemia) or
hyperthermia (dehydration),
tachycardia,
thready pulse,
hypotension,
orthostatic hypotension,
decreased central venous pressure,
tachypnea (increased respirations),
hypoxia
NEUROMUSCULOSKELETAL - DEHYDRATION
Dizziness,
syncope,
confusion,
weakness,
fatigue;
seizures (rapid/severe dehydration)
GI - DEHYDRATION
Thirst,
dry mucous membranes,
dry furrowed tongue,
nausea,
vomiting,
anorexia,
acute weight loss
RENAL - DEHYDRATION
Oliguria (decreased production of urine)
OTHER FINDINGS - DEHYDRATION
Diminished capillary refill,
cool clammy skin,
diaphoresis,
sunken eyeballs,
flattened neck veins,
absence of tears,
decreased skin turgor
Assessment of skin turgor in the older adult might not
provide reliable findings due to a natural loss of skin elasticity.