Funds Ch 35 hydration and homeostasis

Osmosis

The movement of water across a membrane from a less concentrated solution to a more concentrated solution

Hypertonic solutions can

make it easier for the kidneys to remove excess water from your patient’s body. They also decrease blood pressure by reducing the amount of fluid in blood vessels and capillaries

Osmosis example

Red blood cells have a certain concentration of solutes inside them. If you place them in a highly concentrated salt solution, water will move out of the red blood cells, causing them to shrink and crenate (develop pointed edges)

Diffusion

A passive process by which molecules of the solute move through a cell membrane from an area of higher concentration to an area of lower lower concentration

Diffusion example

If you add cream to a cup of coffee, the cream is initially concentrated in the area where poured. However, very soon the cream becomes evenly disbursed throughout the coffee. If you stir the coffee, the cream disperses even more quickly.

Filtration

The movement of both water and smaller particles from an area of high-pressure to one of low pressure

Filtration example

The membrane pours of Bowman capsule, and the kidneys are very small, and only albumin, the smallest of proteins can be filtered through the membrane. By contrast, the membrane pores of liver cells are extremely large, so variety of solute can pass through and be metabolized.

Children have

More fluid in their bodies, and they are more at risk for losing fluid. They lose more fluid than adults

What regulates fluid intake?

Thirst

“No pee no K”

Means if the patient is not peeing then they are not excreting potassium. They will become hyperkalemic.

Calcium levels

8.5-10.5

Magnesium levels

1.6-2.6

Phosphate levels

2.5-4.5

Primary cause of hypomagnesemia

Alcoholism

__ has an inverse relationship with calcium. When calcium goes up, it goes down etc.

Phosphorus

Where to assess skin turgor

Adults - collarbone, top of hand

Infants - Sunken fontanelle

Children - abdomen, sternum

A good indicator of fluid balance

Weight

A very common cause for hyperkalemia

Renal failure

The two interventions for monitoring fluid status

Daily weight, I&O

Isotonic fluids

Fluids remain in the intravascular compartment

can be used for infusion into a patient’s bloodstream without altering their blood volume or pressure. This means that isotonic solutions don’t dehydrate you as quickly as hypotonic or hypertonic solutions

Mannitol

helps to treat and reduce swelling like lowering ICP

What solution is Mannitol

Hypertonic solution

Hypertonic solutions may be given to

counter the effects of fluid overload or pulmonary edema

Hypotonic

Fluids pull body water out of the intravascular compartment (blood vessels) into the cells

Hypertonic

Fluids, pool, body water into the intravascular compartment (space inside blood vessels)

(Pulls fluid out of cells)

Isotonic fluids

0.9% NS

LR

Type of fluid that are useful for clients with hypotension or hypovolemia

LR

0.9%Ns

Hypotonic fluids

D5W

0.45% NS

0.33% NS

0.2% NS

D5W

Is isotonic in the bag, but becomes hypotonic in the body

Never give _ solutions to a patient at risk for increased intracranial pressure because they can cause or worsen cerebral edema

Hypotonic

_ fluids can help stabilize blood pressure, increase, and output, and reduce edema

Hypertonic

_ is used for hyperglycemic conditions, such as diabetic ketoacidosis in which high serum glucose draws fluid out of the cells and into the vascular and interstitial compartments

Hypotonic fluids

Can lower potassium through vomiting or diarrhea

Gastroenteritis

Isotonic fluids have the same osmolality as

blood

Hypernatremia means the body

Has too much salt. Restricting fluids will raise the levels more.

5% loss

Clinically significant fluid loss

8% loss

Severe fluid loss

15% loss

Usually fatal fluid loss

The kidneys regulate

Fluid balance, ADH, aldosterone

Alsosterone

Stimulates the distal tubules of the kidneys to reabsorb, sodium and excrete passion. Sodium reabsorption result in passive reabsorption of water, thereby increasing plasma volume and improving kidney perfusion. When fluid excess is present, Renon is not released, and this process stops.

ADH

Releases from the pituitary gland. Causes the kidneys to retain fluid.

-If the fluid is low within the vascular system fluid pressures within the system decrease, and more this hormone is released.

-If fluid volume increases, less of this hormone is released in the kidneys eliminate more fluid

“Where sodium goes water flows”

Sodium regulates fluid balance. Sodium attracts water wherever it goes and can increase vascular pressure

Hypovolemia causes

Insufficient fluid intake with depression, sedation, or alcohol abuse

Excessive fluid loss through bleeding, vomiting, diarrhea

Fluid shifts as in the intravascular fluid made leak into body tissues, burns

Ways we lose fluid

Through urine, diarrhea, feces, vomiting, gastric drainage

From the lungs, open wounds, burns, skin perspiration, evaporation

Thirst

The first symptom of dehydration

Hypovolemia manifestations

Weakness, fatigue, feeling warm because the temperature increases because the body is less able to cool itself through perspiration. Hypotension

Orthostatic hypotension, the ratio between BUN to creatinine and hematocrit are elevated, urine specific gravity increase.

Rapid, weak pulse and orthostatic hypotension