Fluid/Electrolyte and Acid Base

Capillary permeability

A condition where capillaries allow substances to pass through more easily than normal, possibly resulting in edema or ascites.

Fluid Status

The body's level of hydration, commonly associated with conditions such as anasarca, ascites, or insensible fluid loss.

Hydrostatic pressure

The force exerted by a fluid in a closed system, which can affect fluid distribution in the body and contribute to conditions like oliguria.

Osmosis

The movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.

Osmotic pressure

The pressure needed to prevent the flow of water across a semipermeable membrane, associated with conditions such as orthopnea.

Oncotic pressure

A form of osmotic pressure exerted by proteins in the blood plasma that usually tends to pull water into the circulatory system.

Osmolarity

A measure of solute concentration in the body, which can be a factor in conditions like polyuria or third spacing.

Pressure gradient

The difference in pressure that drives the movement of fluids or gases in the body, involved in maintaining isotonic or hypertonic conditions.

Active Transport

The movement of molecules across a cell membrane from an area of lower concentration to an area of higher concentration, usually against a pressure gradient, requiring energy.

Hormone Regulation

The body's mechanism for controlling hormone levels, which can affect fluid balance and acid-base homeostasis.

ADH

Antidiuretic hormone involved in regulating the body's retention of water, affecting the urine concentration and volume.

Aldosterone

A steroid hormone that promotes the retention of sodium by the kidneys, which in turn controls the regulation of water and salt balance.

Atria natriuretic peptide

A hormone involved in the reduction of expanded extracellular fluid volume by increasing the renal excretion of sodium.

Renin-angiotensin-aldosterone

A hormone system that regulates blood pressure and fluid balance in the body.

Acid base

Refers to the mechanisms the body uses to maintain its normal pH balance.

HCO3

Bicarbonate, an important buffer in the blood to maintain acid-base balance.

CO2

Carbon dioxide, a waste product of metabolism that is transported in the blood to the lungs for exhalation.

Kussmaul breathing

A type of hyperventilation that is the lung's emergency response to acidosis, particularly diabetic ketoacidosis.

Albumin

Normal range: 3.5-5.0 g/Dl. Essential for maintaining oncotic pressure in the vasculature, which prevents fluid leakage and blood vessel collapse.

Hemoglobin

Normal range: 13.5-17.5 g/dl for men, 12.0-15.5 g/dl for women. Critical for transporting oxygen (O2) to tissues and facilitating CO2 (carbon dioxide) return to the lungs.

Complete Blood Count (CBC)

Normal range: WBC 4,500-11,000/mm³, RBC 4.5-5.9 million/mm³ for men, 4.1-5.1 million/mm³ for women, Hematocrit 38.3-48.6% for men, 35.5-44.9% for women. Evaluates overall health and can indicate a variety of conditions, including anemia, infection, and other diseases.

Oxygen Saturation (O2Sat)

Normal range: 95-100%. Represents the percentage of hemoglobin binding sites in the bloodstream occupied by oxygen.

Specific Gravity

Normal range: 1.010-1.030. Indicates urine concentration and reflects kidney function; allows to evaluate the body's water balance and urine concentration.

pH

Normal range: 4.5-8.0. Indicates the level of acidity or alkalinity of urine; can reflect various conditions, including metabolic or respiratory acidosis/alkalosis and kidney function.

HCO3 (Bicarbonate)

Normal range: 22-28 mEq/L. A major element in the body's buffer system to maintain acid-base homeostasis.

Potassium (K)

Normal range: 3.5-5.0 mEq/L (mmol/L). Essential for muscle function, nerve signals, and fluid balance in the body.

Sodium

Normal range: 135-145 mEq/L. Vital for nerve and muscle function, and improper levels can result in hyponatremia, dehydration, hypernatremia, fluid overload, liver disease, and vascular issues.

Extracellular compartments

Composed of interstitial fluid and plasma. The interstitial fluid fills the spaces between cells, and plasma is the liquid part of the blood that carries cells and proteins throughout the body.

Intracellular compartments

Composed mainly of cytosol or cytoplasm within the cell membrane, where numerous cellular processes occur.

Fluid balance assessment by nurse

Includes monitoring intake and output records, assessing vital signs, evaluating tissue turgor, mucous membranes, and presence of edema.

Effect of increased ADH on sodium concentration

ADH would decrease urine water loss which increases blood volume. The increase in blood volume dilutes the amount of sodium in the bloodstream.

ADH response to decreased blood pressure

ADH would increase, leading to water reabsorption in the kidneys to conserve more water and increase blood volume.

Effect of increased aldosterone on sodium concentration

Aldosterone would increase reabsorption of sodium and water which can increase the volume of extracellular fluid.

Aldosterone response to decreased blood pressure

Aldosterone would increase to promote reabsorption of sodium and water by the kidneys to increase blood volume and blood pressure.

Reason for urine concentration with decreased blood pressure

When blood pressure is low, kidneys conserve water to increase blood volume, resulting in more concentrated urine.

Reason for low sodium in vomiting

Vomiting expels stomach contents including gastric fluid that contains a higher concentration of hydrogen ions (H+), leading to a loss of hydrogen ions relative to sodium, thus lowering blood sodium levels.

HCP order for hypertonic fluid

If a patient had hyponatremia, a hypertonic fluid would be ordered because it contains a higher sodium concentration than the serum, which would draw water out of the cells into the bloodstream and help balance the serum sodium.

Expectation of HCP in hypovolemic shock

The HCP would likely order a hypotonic fluid because the main concern in hypovolemic shock is the replacement of lost volume, and a hypotonic solution would hydrate the cells without causing an overload of sodium.

Effect of protein intake on blood pressure

Poor protein intake would likely lead to lower blood pressure levels because albumin helps to maintain oncotic pressure, which draws fluid into the circulatory system, thereby maintaining blood volume and pressure.

Assessment for low albumin

The nurse would anticipate fluid imbalance issues, particularly edema, due to decreased oncotic pressure which normally helps to keep fluid within the vascular space.

Normal serum albumin level

3.5-5.0 g/Dl.

Nursing interventions for low albumin

Monitor vital signs, administer albumin if prescribed, ensure proper nutritional support, and monitor for signs of fluid overload or edema as part of a fluid management plan.

Regulation of fluid balance by Renin-angiotensin system

When BP drops, the kidneys release renin, which converts angiotensinogen to angiotensin I, leading to the production of angiotensin II by ACE. Angiotensin II increases BP and stimulates the release of aldosterone.

Regulation of fluid balance by Aldosterone

Produced in the adrenal glands, it conserves sodium and water in the kidneys, promotes excretion of potassium, increases blood volume and blood pressure.

Regulation of fluid balance by ADH

Released from the posterior pituitary gland when plasma osmolarity increases or blood volume decreases, ADH conserves water by reducing urine volume and increasing water reabsorption in the kidneys.

Regulation of fluid balance by Atrial natriuretic peptide (ANP)

Released from the heart's atria when stretched, ANP reduces sodium and water reabsorption, and thus blood volume, by inhibiting ADH, renin, and aldosterone.

Initiation of the RAAS system

Triggered by a decrease in BP, reduced Na+ levels, or a decrease in blood volume, and by the activation of the sympathetic nervous system.

Risk factors for dehydration in Mr. Duncan

Elderly, profuse diarrhea, oliguria, dark urine, low blood pressure, high pulse, taking diuretics and ACE inhibitors, specific gravity of 1.038 indicates dehydration, and sodium level is above normal.

Subjective assessments for dehydration

Complaints of fatigue, experiencing diarrhea, feeling confused, urine is dark colored, and taking medication that may contribute to dehydration.

Objective assessments for dehydration

Elevated temperature, increased pulse and blood pressure, high sodium level of 150 mEq/L, oliguric with urine output, and high urine specific gravity of 1.038.

Additional assessments needed

Skin assessment, weight assessment, nutritional assessment, orthostatic blood pressure measurements, gait assessment, and last fluid intake.

Best indicator of overall fluid status

Weight assessment, as it can indicate changes in total body fluid volume.

Best location to assess skin turgor

The clavicle, as skin turgor here can be a reliable indicator of hydration status.

Sodium Range

Normal is 135-145 mEq/L. Elevated levels may indicate dehydration.

Hematocrit Range

Normal is 40-54%. Lower levels can suggest dehydration due to reduced water content in RBCs.

Serum Osmolality Range

Normal is 50-1400 mOsm/kg. Increased osmolality is often due to higher solute concentration from dehydration.

BUN/Creatinine Range

Normal BUN is 10-20 mg/dL and Creatinine is 0.6-1.2 mg/dL. Higher ratios may indicate renal stress or impaired kidney function, often associated with dehydration.

Urine Specific Gravity Range

Normal is 1.010-1.030. High specific gravity indicates concentrated urine, often due to dehydration.

Orthostatic Blood Pressure

Involves measuring blood pressure while lying, sitting, and standing to assess for significant changes that may indicate dehydration or volume depletion.

Fall Risk Intervention

Use of call lights, clear communication about the patient's fall risk, and environmental safety measures.

Confusion Intervention

Regular orientation, mental status monitoring, and safety precautions.

Mobility Intervention

Assistance as needed, ensuring the call light is within reach, fall risk education, and potential use of mobility aids.

Monitor Pulse and Blood Pressure

Patient's status may change, and vital signs will show the fluid volume deficit that is occurring.

Check Patient Weight Daily

Weight is the best indicator for fluid change and will show status changes.

Note Urine Color, Osmolality, and Specific Gravity

Lab values will indicate fluid deficiency if abnormal and re-assessment will show a change in status.

Skin Turgor Assessment

Assessing the skin turgor allows nurses to see any changes in fluid levels.

Hydrate with IV Solutions as Prescribed

For patients with mild to moderate fluid deficiency, isotonic IV solutions are often used for fluid replacement.

Isotonic Solution

0.9% normal saline, no change in cell size, cells remain stable.

Hypotonic Solution

Less than 0.9% saline, causes cells to swell as water moves into the cell.

Hypertonic Solution

3% saline, cells shrink as water moves out of the cell.

Fluid Movement with Isotonic Solution

Fluid stays where it is administered.

Fluid Movement with Hypotonic Solution

Fluid moves out of the cell into the vessel.

Fluid Movement with Hypertonic Solution

Fluid moves into the cell from the vessel.

Fluid Regulation

Start with 0.9% normal saline for fluid resuscitation.

H2O and Fluid Regulation in the Body

Skin is waterproof and regulates body temperature via perspiration; thirst center in the hypothalamus; the heart releases ANP to regulate blood pressure; kidneys promote/release renin and ADH, contributing to the RAAS system.

Decreased Blood Pressure

Osmoreceptors in the hypothalamus stimulate posterior pituitary to secrete ADH.

Kidneys and Fluid Regulation

Decreased blood volume or increased blood osmolality triggers kidneys to reabsorb more water, decrease urine output, and increase blood pressure and decrease blood osmolality.

Fluid Volume Deficit (Hypovolemia)

Characterized by loss of fluid and electrolytes, often due to excessive fluid loss, insufficient fluid intake, or failure of regulation mechanisms like the kidneys. Common causes include burns and diarrhea.

Dehydration

The loss of water from the body, which can lead to various health issues.

Fluid Volume Excess (Hypervolemia)

Caused by abnormal water or sodium retention and can be associated with heart failure, liver disease, and increased fluid intake.

Management of Fluid Imbalance

Involves interventions like increasing fluid intake for deficit, skin and injury care, blood pressure and edema monitoring, fluid restriction, and diet education for excess.

Priority ABCs

Airway, Breathing, Circulation - Blood Pressure and perfusion to the rest of the body, Safety.

Sodium as Major ECF Cation

Normal range is 135-145 mEq/L. Functions include vital chemical reactions, nerve impulse transmission, acid-base balance, and regulation of H2O and its excretion. Controlled by kidneys and aldosterone.

Hypernatremia

Occurs above 145 mEq/L. Caused by excess water loss (fever, profuse sweating, diarrhea, dehydration). Manifestations include dry mucous membranes, dry skin, orthostatic blood pressure changes, and reduced urine output. Interventions include isotonic solutions and oral fluids. Priority is circulation assessment and baseline blood pressure monitoring.

Hyponatremia and Hypervolemia

Can indicate kidney dysfunction.

Hyponatremia

Below 135 mEq/L. Causes include excess fluid intake, too little sodium, dilutional effects (true hyponatremia), loss of body fluids, kidney failure, heart failure. Manifestations can be lethargy, dizziness, mental status changes, headache, ECG changes, muscle weakness, impaired nerve function.

Normal Sodium and Water Levels

Decreased sodium and increased water (dilutional) versus increased sodium and water (fluid volume excess).

Symptoms of Sodium Imbalance

Headache, dizziness, loss of consciousness, changes in blood pressure, tachycardia, low sodium levels, full bounding pulse, distended veins, breathing problems.

Assessment and Interventions for Sodium Imbalance

Slow position changes, isotonic solutions, fluid restriction, diuretics, monitoring of symptoms and blood levels.

Hyponatremia Imbalance

Lab value less than 135 mEq/L, specific gravity less than 1.010 indicating diluted urine.

Assessment Findings for Hyponatremia

Altered mental status such as confusion and decreased level of consciousness, muscle weakness, decreased deep tendon reflexes, headache, nausea and vomiting, hyperactive bowels, tachycardia, orthostatic hypotension.

Medication Management for Hyponatremia

Use of potassium-sparing diuretics, monitor intake and output, restrict fluids, administer hypotonic solution carefully, use of vasopressin if necessary.

Interventions for Hyponatremia

Initiate diet with increased sodium, monitor vital signs and level of consciousness, take safety precautions.

Diet for Hyponatremia

Increase intake of sodium through cured meats, cheese, and avoid high water content foods like soups; limit foods with lower sodium like french fries, chips, pretzels, and movie popcorn.

Education for Hyponatremia

Teach about the importance of daily weight checks, slow position changes to prevent dizziness, and avoid overhydration. Emphasize the need to adhere to a heart-healthy diet with appropriate sodium levels.

Hypernatremia Imbalance

Lab value greater than 145 mEq/L, specific gravity greater than 1.030 indicating more concentrated urine.

Assessment Findings for Hypernatremia

Altered cognition such as agitation and stupor, orthostatic hypotension indicating the initial stage, low urine output, irregular muscle contractions, dry skin, and distended flat neck veins.

Medication Management for Hypernatremia

Administration of isotonic solutions, diuretics such as furosemide and bumetanide, and monitoring of fluid intake.

Interventions for Hypernatremia

Increase water intake, monitor vital signs, ensure safety, and restrict dietary sodium.

Diet for Hypernatremia

Follow DASH Diet guidelines, increase protein, fruits, and vegetable intake, monitor processed foods, and prefer cooking at home.