Fluid & Electrolyte Balance

Methods of fluid and electrolyte balance

-Oral and gastric feedings

-Parenteral therapy

How is choice of fluid therapy chosen?

Type and severity of imbalance

Patient's overall health status and age, renal and CV status

Usual maintenance requirements

Diffusion

Solute molecules move from high to low concentration

Osmosis

Solvent molecules move from low to high solute concentration

Osmolarity

Hypotonic

Isotonic

Hypertonic

Isotonic

-The concentration of solutes is the same inside and outside the cell

-Solution that has some tonicity as plasma, does not cause movement of solution in or out of the cell

Hypotonic

-Solution with lower osmolarity than plasma (<275)

-Draws water into cell from ECF

-Cell swells

Hypertonic

>295 osmolarity

-Draws water out of the cell into more highly concentrated ECF

-Cell shrinks

Isotonic IV fluid example

0.9% Normal Saline

LR

Hypotonic IV solution

0.45% Normal Saline

D5W (Dextrose)

Hypertonic IV solution

3% Saline (example of use: pulls fluid from the brain)

D5N5

D10W

D5LR

D50

Nursing process: Implementation replacement of fluids and electrolytes

-Daily weights

-i&o

-Enteral fluid replacement OR restriction of fluids

Oral replacement therapy

-Semi or high fowlers to avoid aspiration

-Maintain accurate i&o records

-Daily weight

-Monitor serum sodium levels, BUN levels, and serum osmolality

-Pt teaching

Why do we need to know about Lab Diagnostics?

-Patient education: explaining to pt and ensure accuracy

-Patient prep: diet restriction, sequencing procedures, protective barriers

-Data interpretation

What variables can affect lab test results?

-Age (peds, middle and older adults)

-Gender (muscle mass, hormones)

-Race has little effect on lab values but greater effect on genetic disease

-Pregnancy

-Food ingestion

-Posture

-Altitude

What lab changes may occur in middle and older adults?

Albumin and total protein decrease

Cholesterol & triglyceride increase

Venipuncture

-Usually in a superficial vein in antecubital fossa of arm

-Collection tubes and tourniquet

Red top collection tube

Allows blood to clot

Blue, green, or lavender collection tube

Prevents blood from clotting

Grey top collection tube

Prevents glycolysis

Venipuncture order of blood draws

-Blood cultures (sterile)

-Light blue (Coag studies)

-Red (chem)

-Red speckled (chem)

-Green (chem)

-Light green

-Lavender (CBC)

-Yellow

-Gray

"Stop Light Red Stay Put, Green Light You Go"

CBC

RBC: What's left after white cells excluded

WBC: Gross count of cells not red

Hbg: Oxygen carrying capacity of blood

Hct: % of total blood volume that is RBC's (Approx 3x Hgb)

High WBC

-Generally points to infection

-Indicates something is wrong somewhere

-Differential WBC is a more detailed analysis of WBC's (neutrophils, lymphocytes, monocytes, eosinophils, basophils)

Sepsis WBC

Extremely high

Leukopenia

WBC count <4500

-Bone marrow failure from chemo/radiation

-Overwhelming infections of autoimmune disease

WBC Interfering factors

-Eating, physical activity, stress

-Pregnancy and spleenectomy

-Time of day

-Age

-Drugs

What can cause electrolyte imbalances?

Illness, burns, or trauma

Na reference values

135-145 mmol/L

K ref value

3.5-5.0 mmol/D

Cl ref value

95-105 mmol/L

CO2 ref value

25-40 mmol/L

BUN ref value

5-23 mg/dl

Creatinine ref value

0.6-1.2 mg/dl

Na panic values

<125 or >150

Hyponatremia <135

-Results from excessive loss of sodium or excessive water gain, diuretic therapy, excessive drinking of water, endocrine disorders

-S/s: HA, N, V, confusion, muscle twitching, tremors, weakness, irritability

-Tx: oral sodium supplements, restrict fluid intake

Hypernatremia >145

-Results from sodium gain in excess water or most commonly water loss in excess of sodium, severe insensible water losses, severe vomiting, sodium excess

-S/s: extreme thirst, restlessness or agitation, anorexia, N, V, dry sticky tongue and oral mucosa, disorientation, hyperactive reflexes, oliguria or anuria, lethargy

-Tx: prescribed oral/IV therapy and sodium restricted diet

K panic values

<2.5 mmol/L

>7.0 mmol/L

80-90% of body K is excreted by kidneys

Hypokalemia

<3.5 mmol/L

Results from excessive GI losses, chronic renal disease, certain drugs/diseases

-S/s: muscle weakness, leg cramps, paresthesia, fatigue, cardiac irregularities, GI complains, EKG changes, decreased reflexes

-Tx: oral K supplements, IV K chloride

Hyperkalemia

>5.0 mmol/L

Results from reduced excretion by kidneys, oliguria due to shock or severe dehydration, potassium-sparing diuretics, certain disease

S/s: irritability, paresthesia, numbness in extremities, skeletal muscle weakness, cardiac arrthymias

Tx: Kayexalate (cation exchange resin, orally or enema)

CO2

CO2 is venous CO2, not to be confused with PCO2 which is arterial

Elevated CO2

Alkalotic (cause: vomiting, gastric suction)

Decreased CO2

Acidotic (cause: chronic diarrhea, loop diuretics, renal failure, diabetic keto)

Elevated BUN and creatinine

Kidney Dysfunction

Increased BUN

Normal Creatinine

Dehydration

Decreased BUN

Normal creatinine

Overhydration

Nutrition Labs

K

Phos

Hgb

Mg

Ca

Alb

Fluid balance labs

BUN

Na

Cl

Hct

Patho labs

BUN/Cr

K

Ca

Phos

Mg

Albumin levels

3.5-5 g/dL

Total calcium levels

8.6-10.5 mg/dL

Ionized calcium levels

4.5-5.5 mg/dL

Mg levels

1.5-2.5 mg/dL

Phosphate levels

2.5-4.5 mg/dL

Total calcium panic values

<6.0 mg/dL

>14.0 mg/dL

Ionized calcium panic values

<2.8 mg/dL

>7.0 mg/dL

Hypocalcemia

<8.6 mg/dL

<4.6 mg/dL

Results from abnormal PTH, inadequate diet intake, excessive losses of bound, ionized, or total body calcium

Tx: calcium supplements PO or IV calcium gluconate or ca chloride

Hypercalcemia

>10 mg <5.5 mg/dL

Caused by increased intestinal absorption, renal abnormalities, pts with metastatic cancer

S/s: lethargy, muscle weakness/flaccidity, hyporeflexia, decreased muscle tone, polyuria, polydipsia, urinary calculi, arrhythmias, cardiac arrest

tx: adequate hydration, biphosphonates, ambulation

Mg panic values

<1.2 >4.9 mg/dL

What does Mg do?

-normal nerve and muscle function

-normal heart beat

-plays a role in almost all chemical processess

Hypomagnesemia <1.5 mg/dL

cause: excessive loss from GI and kidneys, chronic alcoholism, medications

s/s: neuromuscular irritability, weakness, tremors, dizziness, cardiac irritation, mood changes, tetany, convulsions

tx: orl Mg, iv Mg, rich Mg diet

Hypermagnesemia >2.5 mg/dL

causes: renal failure, adrenal insufficient, excessive intake, sepsis, Mg containing meds

s/s: feeling of warm/flushing, hypotension, SOB, drowsiness, hypoactive reflexes

tx: IV calcium gluconate, lasix, glucose, insulin

Phosphorous panic values

<1.5 mg/dL

Phosphorus use in body

-Building strong bones and teeth

-Needed for repair of all tissues/cells in the body

-Essential role in how the body stores and uses energy

Hypophosphetemia <2.5 mg/dL

causes: hyperparathyroidism, aluminum anacids, sepsis, ETOH, intoxication, NGT suctioning, diuretics, vitamin D deficiency

S/s: altered mental status, cardia arrhythmias, dyspnea, heart failure

tx: oral/iv phosphates, control the intake through diet

Hyperphosphatemia >4.5 mg/dL

causes: exercise, excessive enema usage, hypoparathyroidism, dehydration

s/s: tingling around mouth, fingertips, delirium, numbness, muscle cramps, tetany

tx: control intake through diet, acetazolamine (diamox)

Low albumin cause and risks

-inadequate protein intake for 14-20 days

-increase risk for pressure ulcers

-poor wound healing

Serum albumin level affected by

•Hydration

•Hemorrhage

•Renal or hepatic disease

•High-output wound drainage

•Steroid administration

•Albumin IV administration

•Age

•Trauma & stress: surgery, burns

Common labs indicating nutritional status

Serum albumin levels

Transferrin

Pre-albumin

Normal transferrin levels

>250 mg/dl

decreased can mean inadequate protein intake for 7-9 days

Pre-albumin normal levels

20-40 mg/dl

Decreased can mean inadequate protein for 2 days (Acute conditions, less sensitive to hydration status)

LFTs

bilirubin

SGOT/AST: aspartate aminotransferasae, found in many tissues

SGPT/ALT: alanine aminotransferase, found primarily in liver

Renal function tests

BUN and creatinine

Lipid profile tests

Total cholesterol

Triglycerides

LDLs

HDLs

Coagulation panel

PT: prothrombin time

PTT: partial

BUN test purpose

-Liver function and kidney excretion

BUN Increase meaning

-Azotemia/azotemic (elevated levels of urea and nitrogenous waste)

-Protein catabolism

-Dehydration

-Muscle breakdown

BUN Decrease meaning

-Decreased urea synthesis in liver

Creatinine test purpose

-Renal excretion

Causes of Creatinine increase

•Doubling indicates 50% ¯ in GFR

•Glomerulonephritis

•Pyelonephritis

•Acute tubular necrosis

•Urinary obstruction

•Meat Ingestion

Cause of Creatinine decrease

-Elderly and children d/t decreased muscle mass

How much total kidney function must be lost before BUN and creatinine appears outside the normal range?

Around 60% of total kidney function must be lost until BUN and creatinine are out of range

Creatinine clearance

•is a more accurate measure

•used whenever renal disease is suspected

•careful dosing of nephrotoxic drugs is required

GFR

Volume filtered from the renal capillaries into the Bowman's capsule per unit time to measure renal function

Factors used in determining GFR

‣Serum creatinine

‣Age

‣Race

‣Gender

‣Blood Urea Nitrogen

‣Albumin

Normal GFR

80-120

Mild GFR reduction

41-80

Moderate GFR reduction

30-40

Severe GFR reduction

<29

In chronic renal failure, what changes will be seen in urine lab values?

- decrease protein/na

- increase specific gravity

Chronic renal failure: changes in blood lab values

- increase: K, P, Mg, BUN, Creatinine

- decrease: ca, pH

- na may increase or decrease

platelet count

150,000-400,000

PT: prothrombin time

11.2-12.5 seconds

INR

International normalized ratio

therapeutic: 2-2.5 x normal

PTT: Partial Thromoboplastin time

Therapeutic: 1.5-2.5 X normal

Trough

Heparin therapy