Bicarbonate space

Bicarbonate space is about 1/3 body weight. Total base excess of the whole body (mMol)... 

Ringer s lactate, in which lactate is added to Ringer s solution, is probably the most popular crystalloid (salt) solution for intravenous use in humans. The lactate is gradually converted to sodium bicarbonate within the body so that an uncompensated alkalosis is prevented (13). These crystalloid solutions cannot support life without red cells saline passes rather quickly into the tissue spaces of various organs (14), especially the Hver (15). 

Chemical Reactivity - Reactivity with Water Reacts violently, forming corrosive and toxic fumes of hydrogen bromide Reactivity with Common Materials Attacks and corrodes wood and most metals in the presence of moisture. Flammable hydrogen gas may collect in enclosed spaces Stability During Transport Stable if protected from moisture Neutralizing Agents for Acids and Caustics Hood with water, rinse with dilute sodium bicarbonate or soda ash solution Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Patients with acute hyperkalemia usually require other therapies to manage hyperkalemia until dialysis can be initiated. Patients who present with cardiac abnormalities caused by hyperkalemia should receive calcium gluconate or chloride (1 g intravenously) to reverse the cardiac effects. Temporary measures can be employed to shift extracellular potassium into the intracellular compartment to stabilize cellular membrane effects of excessive serum potassium levels. Such measures include the use of regular insulin (5 to 10 units intravenously) and dextrose (5% to 50% intravenously), or nebulized albuterol (10 to 20 mg). Sodium bicarbonate should not be used to shift extracellular potassium intracellularly in patients with CKD unless severe metabolic acidosis (pH less than 7.2) is present. These measures will decrease serum potassium levels within 30 to 60 minutes after treatment, but potassium must still be removed from the body. Shifting potassium to the intracellular compartment, however, decreases potassium removal by dialysis. Often, multiple dialysis sessions are required to remove potassium that is redistributed from the intracellular space back into the serum. 

The extracellular fluid (ECF) is the fluid outside the cell and is rich in sodium, chloride, and bicarbonate. O The ECF is approximately one-third of TBW (14 L in a 70-kg man or 12 Lin a 70-kg woman) and is subdivided into two compartments the interstitial fluid and the intravascular fluid. The interstitial fluid (also known as lymphatic fluid) represents the fluid occupying the spaces between cells, and is about 25% of TBW (10.5 L in a 70-kg man or 8.8 L in a 70-kg woman). The intravascular fluid (also known as plasma) represents the fluid within the blood vessels and is about 8% of TBW (3.4 L in a 70-kg man or 2.8 L in a 70-kg woman). The ECF is approximately one-third of TBW or 14 L in a 70-kg male. Because the exact percentages are cumbersome to recall, many clinicians accept that the ECF represents roughly 20% of body weight (regardless of gender) with 15% in the interstitial space and 5% in the intravascular space.6 Note that serum electrolytes are routinely measured from the ECF. 

Normally, the number of anions and cations in each fluid compartment are equal. Cell membranes play the critical role of maintaining distinct ICF and ECF spaces which are biochemically distinct. Serum electrolyte concentrations reflect the stores of ECF electrolytes rather than that of ICF electrolytes. Table 24-4 lists the chief cations and anions along with their normal concentrations in the ECF and ICF. The principal cations are sodium, potassium, calcium, and magnesium, while the key anions are chloride, bicarbonate, and phosphate. In the ECF, sodium is the most common cation and chloride is the most abundant anion while in the ICF, potassium is the primary cation and phosphate is the main anion. Normal serum electrolyte values are listed in Table 24—5. 

Dextrose and insulin (with or without sodium bicarbonate) are typically given at the time of calcium therapy in order to redistribute potassium into the intracellular space. Dextrose 50% (25 g in 50 mL) can be given by slow IV push over 5 minutes or dextrose 10% with 20 units of regular insulin can be given by continuous TV infusion over 1 to 2 hours. The onset of action for this combination is 30 minutes and the duration of clinical effects... 

Limestone is mostly made up of the mineral calcite, or calcium carbonate (CaC03). As the calcium carbonate rock dissolves in the slightly acidic water, spaces and even caves develop underground. If carbonic acid dissolves all the way through the rock and into a cave below the Earth s surface, the resulting solution contains calcium hydrogen carbonate (calcium bicarbonate). 

Infrared absorption in the atmosphere can have the same effect. Over the last century the concentration of carbon dioxide in the atmosphere has risen dramatically because of combustion. As a result, the atmosphere now absorbs more infrared radiation than it did in the past, and cooling into space is less efficient. A likely consequence is global warming, although a detailed calculation of the magnitude of the expected effect is far from simple. For example, while is it not difficult to estimate total CO2 emissions from combustion, most of these molecules end up in the ocean as carbonates or bicarbonates, and do not directly contribute to global warming. Nonetheless, there is broad consensus in the scientific community that carbon dioxide emissions will tend to increase the Earth s temperature over the next few decades, with environmental consequences which may be severe. 

The systems using the larger packing are used in the treatment of relatively strong, low-suspended-solids industrial waste. These systems are closed columns usually run in an upflow mode with a gas space at the top. These are operated under anaerobic conditions with waste conversion to methane and carbon dioxide as the goal. Effluent recycle is often used to help maintain the pH in the inlet zone in the correct range 6.5-7.5 for the methane bacteria. Some wastes require the addition of alkaline material to prevent a pH drop. Sodium bicarbonate is often recommended for pH control because it is easier to handle than lime or sodium hydroxide, and because an overdose of bicarbonate will only raise the pH modestly. An overdose of lime or sodium hydroxide can easily raise the pH above 8.0. Table 22-48 gives... 

The concentrations of the various forms of C02 present in an aqueous phase are temperature dependent and extremely sensitive to pH (the concentrations also depend on the presence of other solutes, which presumably is a small effect for the cell wall water). For instance, the equilibrium concentration of C02 dissolved in water divided by that of C02 in an adjacent gas phase, Cc 7cccv decreases more than two-fold from 10°C to 40°C (Table 8-3 the decreasing solubility of C02 as the temperature increases is a characteristic of dissolved gases, which fit into the interstices of water, such space becoming less available as molecular motion increases with increasing temperature). This partition coefficient is not very pH dependent, but the equilibrium concentration of HCO3- in water relative to that of dissolved C02 is markedly affected by pH. In particular, C02 dissolved in an aqueous solution can interact with water to form carbonic acid, which then dissociates to form bicarbonate ... 

Thus the bicarbonate buffer in the liver with its components CO2 and HC03 is also used for maintaining pH homoeostasis. The various cellular and subcellular compartments can only keep their own specific pH values constant provided the pH value of the extracellular space is not subject to major fluctuations. A constant balance between the formation and excretion of CO2 and HCOj must therefore be guaranteed. Bicarbonate neutralization takes place, energy-driven and irreversibly, in the urea cycle. In this context, HC03 is considered to be a relatively strong base, whereas NH4+ is regarded as a weak acid. 

FIGURE 10.12 Sodiuin bicarbonate resorption by cells of the proximal renal tubule. (1) Sodium enters through the apical membrane via the Na-H exchanger. (2) The resorbed sodium passes out of the celJ into the interstitial space by way of the Na-HCOj COtrans-porter. f3) The bicarbonate in the filtrate accepts a proton to become carbonic acid. Steps that ate catalyzed by carbonic anhydrase are indicated by (CA). 

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