![]() marked hyperlipemia or hyperproteinemia.Ĭhanges in the osmolality of ECF may or may not initiate movement of water between the ICF and ECF. ethylene glycol, mannitol or false decreases in sodium or pseudohyponatremia, e.g. This indicates the presence of unmeasured osmoles (“unmeasured” in terms of the calculation) e.g. Osmolal gap = Measured – calculated osmolality The osmolal gap is the difference between the measured and calculated serum osmolality: The calculated osmolality is typically about 280-310 mOsm/kg in healthy animals, whereas measured osmolality ranges from 290-310 mOsm/kg in dogs, 290-330 mOsm/kg in cats, and 280-320 mOsm/kg (with minor differences in EDTA- or lithium-heparinized plasma) in horses ( Wilkinson 1976). With 18 and 2.8 being factors, which convert mg/dL (conventional units) to mmol/L (SI units) Calculated (estimated) if the serum concentrations of Na, K, glucose, and urea nitrogen (UN also referred to as blood urea nitrogen or more correctly serum urea nitrogen or plasma urea nitrogen ) are known:.Measured directly with an osmometer using freezing point (technique used in the clin path lab) or vapor pressure depression.In biologic fluids, there is a negligible difference between osmolality and osmolarity and the terms are often used interchangeably. Osmolarity is simply the concentration per liter of solvent. In clinical veterinary medicine, osmolality is expressed as milli-osmoles per kg. Osmolality refers to the number of osmotically active particles (osmoles) per kilogram of solvent. Despite these differences, the total number of all cations and anions in body fluids are equal to maintain electroneutrality. Sodium and chloride are much higher in the ECF than potassium, which is higher in the ICF (remember, that in most cells, Na/K transporters pump out and K in). Solutes are not distributed equally throughout body fluids, due to the vascular endothelium and different permeability of cell membranes for various solutes. The composition of the ICF and ECF are very different. cerebrospinal fluid, GI fluid, bile, glandular and respiratory secretions, and synovial fluid). The transcellular fluid compartment is small (about 1% of body weight) and consists of fluids produced by specialized cells (e.g. Most ECF is present in interstitial fluid (around 3/4), with the remaining 1/4 of ECF within blood vessels (intravascular compartment) as plasma. Dense connective tissue, cartilage, and bone also contain a small amount of ECF. The ECF is further separated into interstitial fluid (space surrounding cells), intravascular compartment (plasma), and transcellular compartment. The 60:40:20 rule can help you remember the distribution of body water: 60% of body weight is water, 40% of body weight is ICF, and 20% of body weight is ECF. In most disease states, loss of fluids occurs initially from the ECF, particularly from plasma or the intravascular compartment. Any fluid not inside of cells is in the extracellular fluid (ECF) compartment (the remaining 1/3 of total body water). The largest volume of fluid in the body is inside cells (the intracellular fluid or ICF compartment) and makes up about 2/3 of total body water. The fluids in each compartment equilibrate by multiple mechanisms to maintain homeostasis. The ECF compartment can be split into interstitial fluid and plasma compartments. ![]() Water is the major component of all body fluids, which are distributed into several physically distinct compartments, including the intracellular fluid (ICF) and extracellular fluid (ECF) compartments. This is the reason behind estimating fluid needs on “lean body weight” and not total body weight. Fat has a lower water content than lean tissue. In greyhounds, approximately 70% of their total body weight is water (likely due to low body fat content). Neonatal dogs and cats have higher total body water content (about 80%) compared to adults. For example, in humans, total body water decreases with age and is lower in women than in men. In health, approximately 60% of an adult animal’s body weight is water, but this varies with species, age, sex, breed, and body composition.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |