Fluid Balance and IV Solutions

Fluid Imbalance

• Osmosis involves fluid movement through a semipermeable membrane from low to high solute concentration until equilibrium.
• Hydrostatic pressure pushes fluid out of blood vessels into tissue on the arterial capillary side.
• Osmotic (oncotic) pressure pulls fluid from the tissue back into the blood vessel on the venous capillary side.
• Protein, glucose, and sodium are molecules involved in this process
• Tonicity of IV fluids determines the direction of fluid flow, depending on the number/size of molecules in the solution.

IV Solutions and their effects:

• Isotonic solutions are commonly used and move fluids equally without altering cell size, preferred for fluid replacement due to similar tonicity (sodium conc) to blood.
• Hypertonic solutions attract fluid into the bloodstream due to high solute concentration that includes large molecules like proteins and glucose, and high levels of sodium.
• Hypertonic solutions are used when rapid fluid replacement is needed or when tissue is over-hydrated (edema) to pull fluid out.
• Hypotonic solutions cause fluid to move out of the bloodstream, used when tissue is dehydrated.

Important IV Solution Examples:

• Isotonic: 0.9% normal saline (NS) and lactated ringers (LR).
• Hypertonic: 3% saline, 6% saline, Albumin, D50, hetastarch
• Hypnotonic: 0.45% NS; 0.225% NS; or D5W

Nursing considerations

• Caution is needed when administering IV fluids to avoid fluid overload, especially in the lungs.
• Monitor patient's lungs and breathing patterns for signs of fluid overload.
• “Fluid Challenge" involves giving IV fluid increments of 500 mL.
• Patient assessment must be done between administrations to avoid over-administering
• Notify the provider if "wet lung sounds" heard

Edema

• Edema is tissue swelling that can impair blood flow, reduce healing, trap metabolic wastes, and increase heart workload.
• Edema increases blood pressure and can caused chronic hypertension

Life-threatening edema

• Laryngeal: potentially blocks the patient's airway
• Pleural: breathing gets impaired
• Cerebral: the brain functionality stops due to too much fluid around the brain

Third-spacing

• The movment of too much fluid moves from the intravascular space into the interstitial space
• This can cause potential problems like reduced blood pressure, cardiac output issues and edema

Measuring Edema

• Dependent edema (in legs) is a common finding in congestive heart failure. -Daily weights should be taken to monitor water gain and loss.

Edema treatment

• Diuretics remove excess water by triggering the kidneys
• Hypertonic fluids pull fluid out of tissues for kidney excretion.

Water and Sodium Regulation

• The hypothalamus contains thirst trigger, and gets triggered by the central nervous system
• Cellular dehydration is caused by increased ECF osmolality, for example, blood that is too thick
• Hypovolemia is low blood volume, one of the earliest signs of hemorrhage

ADH

• Regulates water via signaling the kidneys to retain water and sodium, released with increased blood concentration, and excreted with low blood volume/sodium and high fluid osmolality.

Electrolyte Imbalance

• Cations: Na+, K+, Ca++, and Mg+
• Normal range varies for each one
• Each electrolyte either excites or calms tissue
• Imbalance s/s will vary if its hyper/hypo

Functions of Major Cations

Extracellular

• Sodium excites the nervous system, affects both Brain and nerves, changes in LOC and seizures.
• 135-145 is the average range

Intracellular

• Potassium affects Cardiac tissue as well as the heart.
• Affects the muscles, GI tract and can cause dysrhythmias.
• Can cause Nausea, vomiting and seizures
• An affect of too much potassium, can cause diarrhea and dysrhythmias
• An affect of low potassium can cause constipation
• 3.5 - 5.0 is the average range

More Electrolyes and Their Imbalances

Calcium

• Normal Range: 8.5-10.5
• Calms muscle nerves affecting the heart & blood pressure
• Low Ca can cause Tetany, severe low Ca will cause laryngeal spasms
• High Ca can cause muscle weakness

Magnesium

• Normal Range: 1.5-3.0
• Calms and smooths muscle function affecting DTRs
• Includes the lungs, uterus, heart, and intestines.
• Low Mg can cause hyperreflexia
• High Mg, can cause respiratory failure and laxative stool

Acid/Base Imbalance

• Balanced by 3 Mechanisms

Respitory system

• Respiratory rate of 35-45 to blow off excess of CO2
• Takes several minutes to hours

Renal system

• Controls Hydrogen excretion, to control acid and Bicarbonate to control the base
• Takes several hours to days

If acidotic

• If the body is acidotic, the lungs raise Ph by blowing off C02 causing deep rapid breathing also known as Kussmaul breathing pattern
• If the body is alkalotic, the body will try to compensate by retaining C02 caused by hyperventilation, fever and anxiety

Metabolic regulation

• If the body is Acidotic, the kidney excretes hydrogen to get rid of acid and retain bicarb to neutralize
• If the body is alkalotic, the kidney retains hydrogen to excrete bicarb

Causes of Acid/Base Imbalances

• Excess of Reatined CO2 leads to acidiodis
• Lung injury/insult, disease etc also lead to retainment of carbon

Effects of Acid/Base Imbalances

• Acidosis leads to depression in the Central nervous system
• Severe acidosis causes death, disorientation and Coma
• Alkalosis leads to an excitation of the Central nervous system.
• Sever Alkalosis causes Muscle spams, death and convulsions

Interpreting Arterial Blood Gas Results

• Determine from the pH if the condition is ACIDOSIS or ALKALOSIS
• Below 7.35 = ACIDOSIS
• Above 7.45 = ALKALOSIS Determine from the CO2 and Bicarb if the condition is RESPIRATORY or METABOLIC same direction with metabolic and reverse with respitory
• Compensated= PH normal and other values are abnormal
• Uncompensated= PH abnormal and 1 other value is abnormal
• Partially compensated= All values are abnormal

GAS

• SaME direction = MEtabolic
• REverse = REspiratory values

Stress and Adaptation

• Mental or physical stress will trigger a phisological response.
• Short term stress can return the body back to normal but long term stress can bring many diseases

General Adaptation Syndrome

• Alarm Stage: CNS Arroused, body defenses mobilized and cortisol response
• Resistance/Adaptation: Full mobilization of our resources and cope while being stressed
• Stage of exhaustion: Continuous process causing breakdowns of homeostasis. This mark is onset on certain disease

Body chemistry on the stress response

• Hormones prepare action and Cortisol mobilizes energy.
• Epinephrine Chief effects on cardiovascular system
• vasodilation of blood vessels that supply these organs

Norepinephrine

• The effects complement of Epinephrine.
• It works in the blood vessel of the visera and causes increased mental awareness

Cortisol

• Acts as both a mediatoe and inhibitor of the stress to prevent over activation of SNS
• Increases Glucose, amino acid, lipid and fatty acids, and delivers the to the bloodstream
• Elevates glucose levels wich causes prolonged stress that leads to diabetes

Antidiuretic Hormone (ADH)

• Stimulates the kidney to retain fluid, while increasing the blood pleasure from the pituitary gland.
• It alos participates in the Renin-Angiotensin-Aldosterone pathway

Prolonged Stress

• increases Sympathetic Nervous System and heart rate prolonged
• Increases in number of diseases due to its effects

Immune system affect

• Immune systems decreases in lymphocyte production which causes infections
• Reactivates latent in vires such as herpes

Gastrointestinal system

-Is deactivated by the Sympathetic system because it is not needed.

• Which causes peristalsis, ulcers and bowl problems

Endorcrine system

• It can cause hormone imbalances in women
• Responsible for hormones that may cause stress and depression and eating disorders

Central Nervous System

• Protein, lethargy, and catabolsim
• Depression increases axiety and is an neurotransmitter.

Cancer

• Decreases repair of DNA and the immune system cancer cells, and can cause psychosocial interventions.

Autoimmune disorders

• It occurs in humoral activity where the autoimmune sytem does not recognize its own body