Review intracellular extracellular body fluid compartments
In 1957, Holliday 8 published a formula that linked body weight to energy expenditure ( Table 113-3).
When oral intake is replaced by parenteral fluids in children, the amount of fluid (i.e., water) given depends on body weight and energy expenditure. Infants and small children are unable to regulate their intake because they do not have access to water for the same reasons that apply in older children or adults in coma or with reduced levels of consciousness. In the normal healthy individual, water intake is regulated by thirst stimulated via osmoreceptors in the hypothalamus. However, in critically ill children, urinary Na and K concentration may be much higher. This assumes that these are the amounts of cations needed for normal homeostasis. The commonly used values for sodium (Na) and potassium (K) requirements in parenteral fluids in children are 2 to 3 mmol/kg/d and 1 to 2 mmol/kg/d. Urine is the major source of electrolyte loss in the body except when there are fluid losses from the gastrointestinal tract. Typically this occurs in gastroenteritis, where reduced oral intake is combined with excessive water and electrolyte loss in the stool. High solute load and limited urine concentrating ability makes them prone to significant ECF contraction (dehydration) when there are excessive amounts of water loss. In addition, the infant’s high metabolic rate and the solute load from enteral feeding formula means they require more water excretion per unit solute amount. 2 Infants are somewhat disadvantaged compared to the older child and adult in that they cannot maximally dilute (infant 200 mOsm/L versus adult 80 mOsm/L) and concentrate urine (infant 800 mOsm/L versus adult 1200 mOsm/L). The average osmolar excretion in newborn infants receiving infant formula is 16 to 20 mOsm/kg/d. Obligate water excretion in the urine is dependent upon solute load and the ability to concentrate and dilute urine. TABLE 113-2 Water Losses in Normal Children (mL/100 kcal/24 h) 4 – 7 Further discussion of fluid and electrolyte physiology in the preterm infant is beyond the scope of this chapter. 3 In addition, glomerular filtration rate is lower than in the term infant, and the large surface area–to–body weight ratio leads to considerable evaporative losses. Fractional excretion of sodium is inversely correlated with age in the preterm, who is susceptible to both sodium loss and sodium and volume overload. The preterm infant has a relative expansion of both TBW and ECF volume expansion, and a diuresis in the first few days of postnatal life is a common finding. By term, ECF and intracellular fluid (ICF) volume has fallen to 45% and 30% of TBW, respectively ( Figure 113-1). During early fetal life, TBW represents 90% of total body weight, with 65% being in the extracellular fluid (ECF) compartment. 1, 2 Total body water (TBW) is high in the fetus and preterm infant. Their earliest, most preventable and reversible stages.Body water content changes significantly with age in children.
#Review intracellular extracellular body fluid compartments full
(physiological), Full Body 3D Bio-Electro (functional) Scan together with a Live andĭried Blood Analysis to identify asymptomatic and often life-threatening dis-eases in Must do: Non-invasiveand non-radioactive Full Body Comprehensive Medical Diagnostic Scan, which includes a Full Body Medical Ultrasound (anatomical), Full Body Medical Thermography The other 1/3 or 20% of body weight is extracellular fluid. From the total body water, 2/3 of that, or 40% of body weight is intracellular fluid. On average total body water in a person is about 60% of their body weight. Interstitium is a contiguous fluid-filled space existing between a structural barrier, such as a cell wall or the skin, and internal structures, such as organs, including muscles and the circulatory system. This mixture of small molecules is extraordinarily complex, as the variety of enzymes that are involved in cellular metabolism is immense. Consists mostly of water, dissolved ions, small molecules, and large, water-soluble molecules (such as proteins). Intracellular fluid (ICF) is the cytosol within the cell. … Lymph returns proteins and excess interstitial fluid to the bloodstream. Lymph also transports fats from the digestive system (beginning in the lacteals) to the blood via chylomicrons. Interstitial fluid – the fluid which is between the cells in all body tissues – enters the lymph capillaries. May be divided into three types: interstitial fluid (IF) in the “interstitial compartment” (surrounding tissue cells and bathing them in a solution of nutrients and other chemicals), blood plasma and lymph in the “intravascular compartment” (inside the blood vessels and lymphatic vessels). Extracellular fluids (ECF) surrounds the cells serves as a circulating reservoir.