Fluid and Electrolyte Imbalances Med surg

These vocabulary flashcards cover the anatomy, physiology, clinical manifestations, and laboratory findings associated with fluid volume deficit and fluid volume overload as presented in the lecture.

Total Body Water Percentage

The body is approximately $60\%$ water, though this varies by age and sex: infants are $75\%$, women are $50\%$, and older adults are $45$ to $50\%$.

Intracellular Fluid (ICF)

The fluid contained within the body cells which comprises $66\%$ of the total body water and totals about $25$ liters.

Extracellular Fluid (ECF)

The fluid compartment comprising $33\%$ of total body water that is the most important area for maintaining homeostasis. It is divided into the intravascular and interstitial spaces.

Intravascular Space

The area within blood vessels, including the heart chambers, arteries, veins, and capillaries, where fluid and electrolyte levels are measured via venipuncture.

Interstitial Space

Also known as tissue spaces, this refers to the area located in between the cells all over the body.

Hemorrhage

The clinical term for when blood leaks out of the intravascular compartment.

Homeostasis

The state in which fluid and electrolyte levels are maintained in a precise balance to prevent a patient from becoming symptomatic.

Obligatory Urine Output

The requirement of $400$ to $600\,mL$ of urine output per day; if output falls below this, wastes are retained and the patient risks electrolyte and acid-base imbalances.

Insensible Water Loss

Fluid lost through the skin (sweat), lungs (breathing), GI tract (stool), and surgical drains.

Fluid-to-Weight Equivalency

One liter ($1\,L$) of water equals one kilogram ($1\,kg$), which is equivalent to $2.2$ pounds ($lb$).

Fluid Volume Deficit

A condition where fluid intake or retention does not meet the body's needs, often caused by hemorrhage, vomiting, diarrhea, burns, or diuretic use.

Skin Tenting

A sign of dehydration where the skin, when pinched over the sternum or back of the hand, remains in a peaked position due to poor turgor.

Urine Specific Gravity

A measure of urine concentration normally ranging from $1.005$ to $1.03$; values greater than $1.03$ indicate the patient is "drier" or dehydrated.

Azotemia

A condition characterized by an elevated Blood Urea Nitrogen ($BUN$) level, for which dehydration is a very common cause.

BUN-to-Creatinine Ratio

A diagnostic ratio that is normally $10:1$ to $20:1$; in dehydration, this ratio rises, often resulting in a $BUN$ greater than $20$ with a relatively normal creatinine.

Psychogenic Polydipsia

A psychiatric disorder characterized by compulsive water drinking faster than the body can eliminate it, leading to water intoxication.

SIADH (Syndrome of Inappropriate Antidiuretic Hormone)

A condition often seen in lung cancer patients where the body secretes excessive antidiuretic hormone, causing the patient to hold on to too much water.

Fluid Volume Overload Symptoms

Clinical signs including bounding and increased pulse, elevated blood pressure, dyspnea, crackles on auscultation, and peripheral edema.

Anasarca

A condition characterized by extreme, diffuse edema located everywhere on the body, including the hands, arms, abdomen, and legs.

Dependent Edema

Edema that settles in the lowest areas of the body due to gravity, such as the ankles and feet when standing, or the sacrum and back when lying down.

Loop Diuretics

The mainstay drug therapy for fluid volume overload, such as furosemide ($\text{Lasix}$) and bumetanide ($\text{Bumex}$), which promote fluid excretion but also waste potassium.