![]() Normal saline vs balanced crystalloids as resuscitation fluid is something of a critical evaluation of the use of normal saline in critically ill patients, with advantages and disadvantages.Normal saline, and why it is anything but "normal" is a description of the pharmaceutical of saline, with a focus on what's in the bag (i.e not much physiology).Locally, normal saline is also discussed in several other chapters Single best reference for further information decrease in bicarbonate and base excess (also up to 3 mmol/L) nontrivial chloride elevation (up to 3 mmol/L) trivial sodium elevation (~0.5-.0 mmol/L) ![]() effect is greater during the infusion (prior to redistribution) below the circulatory reflex activation threshold by 25% of the infused volume, after 25-30 minutes Half life is 20-40 minutes in healthy volunteers, longer in shock states and in mechanically ventilated patients (up to 8 hours)Įxpands the extracellular fluid volume and changes the biochemistry of the body fluids (thus: 25% remains intravascular, 75% becomes interstitial)Īs a resuscitation fluid, you could say that the target receptor is the baroreceptorĮlininated renally, where specific reabsorption mechanisms in the renal tubule regulate the rate of sodium and chloride excretion VOD=0.2L/kg, basically confined to the extracellular fluid Therefore, it should be remembered that both the ECF found in plasma and the ICF found in erythrocytes, contribute to the total blood volume.IV, subcutaneously, orally, or as a neb (plus multople others) It should be pointed out that the plasma volume is not the same as the blood volume, as the volume of erythrocytes contributes nearly 40% of the entire blood's volume. As mentioned, the plasma is separated from the interstitial fluid by the vascular wall which is permeable to water and small solutes but not proteins. The plasma refers to the total volume of ECF within the vascular space.Consequently, the interstitial fluid is composed of roughly the same chemical composition as the plasma except without the proteins. As described in microcirculatory physiology, the vasculature allows free movement of water and small solutes but not of proteins. The Interstitial Fluid refers to the total volume of ECF outside of the blood vessels and is separated from the plasma (see below) by the walls of the body's vasculature.These compartments are separated by the vasculature. The ECF is sub-divided into two other fluid compartments known as the Interstitial Fluid and the Plasma. The ECF contains roughly one-third of the total body water or about 20% of total body weight. As mentioned before, the ECF is separated from the ICF by the plasma membrane of each cell which is impermeable to nearly all classes of solutes. The Extracellular Fluid (ECF) refers the total volume of fluid outside of cells.The ICF contains roughly two-thirds of the total body water or about 40% of total body weight. Although the plasma membrane is permeable to water, it is highly impermeable to both ionic and small solutes as well as proteins. The ICF is separated from the Extracellular Fluid (see below) by the plasma membrane of each, individual cell. The Intracellular Fluid (ICF) refers to the fluid present inside cells and is considered the sum total of the fluid volume in all of the body's cells.The vascular wall is permeable to water and small solutes but not proteins. The plasma membrane is permeable to water but not small solutes or proteins. Each of these compartments is separated by the barriers shown above with unique physio-chemical properties. The ECF is itself divided between fluid within the vasculature itself, known as plasma, and that outside the vasculature, known as the interstitial fluid. The remainder is within the extracellular space as the Extracellular Fluid (ECF). ![]() Two-thirds of total body water is held within cells as Intracellular Fluid (ICF). Roughly 60% of the total body weight is water. Below we discuss how these compartments are defined, the nature of their separating barrier, and how much of the fluid volume each compartment contains in a healthy individual. In a healthy individual, fluid is divided between these functional compartments in certain ratios.
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