fluid replacement

Also found in: Dictionary, Thesaurus, Legal, Encyclopedia, Wikipedia.

fluid replacement

Administration of liquids to a patient by any route to correct volume and electrolyte deficits. The deficit may be physiological, as when a ballplayer sweats excessively without rehydrating on a hot day. It may be pathological, as in traumatic or septic shock, acute respiratory distress syndrome, severe vomiting or diarrhea or both. It may be metabolic, as in diabetic ketosis or adrenal insufficiency. See: intravenous infusion for illus; central venous catheter; central line; intravenous infusion; oral rehydration therapy; solution

The goal of fluid replacement is to correct electrolyte, fluid, and acid-base imbalances. The oral route of replacement is used if possible. The intravenous, intraperitoneal, or subcutaneous routes are also used, with the intravenous route being used most frequently. Fluids may be isotonic, hypotonic, or hypertonic; may contain certain crystalloids (e.g., sodium, potassium, chloride, or calcium); or may contain osmotically active substances (e.g., glucose, protein, starch, or a synthetic plasma volume expander such as dextran or hetastarch). The composition, rate of administration, and route depend on the clinical condition being treated.


A critically ill patient receiving fluid replacement should be monitored frequently to be certain that fluid overload is prevented and that the solution is flowing and not extravasating. This is esp. important in treating infants, small children, and the elderly.


1. a liquid or gas; any liquid of the body.
2. composed of molecules which freely change their relative positions without separation of the mass.

allantoic fluid
the fluid contained within the allantois.
amniotic fluid
the fluid within the amnion that bathes the developing fetus and protects it from mechanical injury.
ascitic fluid
see ascites.
fluid balance
a state in which the volume of body water and its solutes (electrolytes and nonelectrolytes) are within normal limits and there is normal distribution of fluids within the intracellular and extracellular compartments. The total volume of body fluids should be about 60% of the body weight, and it should be distributed so that one-third is extracellular fluid and two-thirds intracellular fluid. Although this distribution remains constant in a healthy animal, there is continuous movement of fluid into and out of the various compartments. See also dehydration, water intoxication.
body f's
the fluids within the body, composed of water, electrolytes and nonelectrolytes. The volume and distribution of body fluids vary with age, sex and amount of adipose tissue. Throughout life there is a slow decline in the volume of body fluids; obesity decreases the relative amount of water in the body.
Although the body fluids are continuously in motion, moving in and out of the cells, tissue spaces and vascular system, physiologists consider them to be 'compartmentalized'. Fluid within the cell membranes is called intracellular fluid and comprises about two-thirds of the total body fluids. The remaining one-third is outside the cell and is called extracellular fluid. The extracellular fluid can be further divided into tissue fluid (interstitial fluid), which is found in the spaces between the blood vessels and surrounding cells, and intravascular fluid, which is the fluid component of blood.
The maintenance of a proper balance between the intracellular and extracellular fluid volumes is essential to health. In patients with heart failure and renal failure the balance becomes upset, producing either localized or generalized edema. Excessive fluid loss produces fluid volume deficit causing cellular dehydration and impaired cellular function.
Bouin's fluid
a histological fixative.
cerebrospinal fluid
the fluid contained within the ventricles of the brain, the subarachnoid space, and the central canal of the spinal cord. See also cerebrospinal fluid.
fluid dram
see fluid dram.
fluid extract
a liquid preparation of a vegetable drug, containing alcohol as a solvent or preservative, or both, of such strength that each milliliter contains the therapeutic constituents of 1 gram of the standard drug it represents.
fetal fluid
allantoic plus amniotic fluids.
interstitial fluid
the extracellular fluid bathing the cells in most tissues, excluding the fluid within the lymph and blood vessels.
isotonic fluid
having the same tonicity or osmotic pressure as blood.
lacrimal fluid
aqueous fluid secreted by the lacrimal glands; called also tears.
fluid line
in radiographs, the interface between fluid and gas, as in the gastrointestinal tract, will show as a straight line.
fluid loss
by vomiting, diarrhea, polyuria, water deprivation. See dehydration.
fluid mosaic model
the modern concept of the structure of a biological membrane developed by S.J. Singer and G.L. Nicolson. In it the membrane consists of protein molecules partly embedded in a discontinuous bilayer of phospholipids that form the matrix of a mosaic of functional cell units.
fluid ounce
see fluid ounce.
pericardial, pleural, peritoneal fluid
normally present in amounts sufficient only to lubricate the movement of viscera within the respective cavities. Composition similar to blood serum.
fluid replacement
see fluid therapy (below).
fluid restriction
the limitation of oral fluid intake to a prescribed amount for each 24-hour period.
fluid retention
see edema.
spinal fluid
the fluid within the spinal canal.
fluid splashing sounds
audible when gas and fluid are free in a cavity, e.g. abomasum in cases of abomasal displacement; can be elicited by shaking a small animal or part of a large animal (i.e. succussion) or by simultaneous percussion and auscultation.
synovial fluid
fluid therapy
aims to replace fluids lost by disease process or by restriction of intake, or to maintain a high rate of fluid excretion to ensure removal of toxins, or to administer therapeutic or anesthetic agents slowly over a long period. The amounts and route of administration vary with the need of the patient. Normal solutions include 5% dextrose and Ringer's solution; alkalinizing fluids include lactated Ringer's and 1.3% sodium bicarbonate; acidifying solutions include isotonic saline and 1.9% ammonium chloride.
fluid thrill
see thrill.
fluid volume deficit
an imbalance in fluid volume in which there is loss of fluid from the body not compensated for by an adequate intake of water. The major causes are: (1) insufficient fluid intake, and (2) excessive fluid loss from vomiting, diarrhea, suctioning of gastric contents, or drainage through operative wounds, burns or fistulae. Decreased volume in the intravascular compartment is called hypovolemia. Because water moves freely between the compartments, extracellular fluid deficit causes intracellular fluid deficit (cellular dehydration), which leaves the cells without adequate water to carry on normal function.
fluid volume excess
an overabundance of water in the interstitial fluid spaces or body cavities (edema) or an excess of fluid within the blood vessels (hypervolemia) and water intoxication.
Factors that contribute to the accumulation of edematous fluid are: (1) dilatation of the arteries, as occurs in the inflammatory process; (2) reduced effective osmotic pressure, as in hypoproteinemia, lymphatic obstruction and increased capillary permeability; (3) increased venous pressure, as in congestive heart failure, thrombophlebitis and cirrhosis of the liver; and (4) retention of sodium due to increased reabsorption of sodium by the renal tubules.
fluid wave
see thrill.
References in periodicals archive ?
Someone losing four litres of sweat without fluid replacement will lose 10 per cent of body water but only four per cent of body sodium.
Also noted on the whiteboard was a tally of urine drainage intra-operatively in combination with accurate fluid replacement volumes avoids a fluid deficit or overload;
Fluid replacement and performance during the marathon.
17) Also, various species respond differently to dehydration and water deprivation based on their geographical habitat of origin, consequently they may respond differently to fluid replacement therapy.
Once chylothorax is diagnosed, pleural drainage, fluid replacement, bowel rest and TPN should be the first steps.
Exaggerated fluid replacement causes edema and weight gain during the postoperative period.
Fluid replacements may be attempted by small, frequent amounts of clear fluids (see clear fluids information in previous section).
Once the decision to intervene has been made, there are several options for fluid replacement, each with advantages and drawbacks.
Be especially mindful of fluid replacement in a dry climate, and remember in general that your perceived desire for fluid does not keep up with the body's needs.
Oral rehydration therapy is the cornerstone of fluid replacement and the new low-osmolarity formula of oral rehydration salts (ORS) is a simple, inexpensive and life-saving remedy that prevents dehydration in children suffering diarrhoea.
The 1510 small character continuous ink jet printer includes an intuitive user interface and simplified fluid replacement with a Smart Cartridge microchip-enabled bottle.
Perhaps the most important and easiest form of prevention of the common cold is sufficient fluid replacement.