Serum sodium

Monitor the following serial laboratories for comparison to baseline values every 6 hours in the first 24 hours and daily thereafter until normalized sodium, serum creatinine, blood urea nitrogen, serum lactate, glucose, bilirubin, hemoglobin, hematocrit, platelets, prothrombin time, partial thromboplastin time, arterial blood gases, and pH. 

Blood pressure, pulse, serum electrolytes, urine volume, urinary sodium, serum creatinine, blood urea nitrogen, electrocardiogram, hepaticfunctiontests, infusion rate... 

The precision and accuracy performance was tested by correlating the measured assays of horse serum specimens to assay values obtained by a standard method. The precision was measured by replicating assays at three sodium serum levels that extend well beyond the clinical range. The correlation plot is shown in Figure 9 and corresponds to a set of samples encompassing a sodium range of 100 to 170 mEq/L. 

Other laboratory tests to assist in assessment and treatment include blood pH, serum C02, or PC02 (any 2) serum sodium serum potassium, BUN blood glucose and urine pH and sp gr. These determinations and the serum salicylate level should be followed serially during therapy (15). 

A second method uses sodium periodate (NaI04) as the oxidant in the presence of the readily available protein bovine serum albumin. In this procedure, the sulfide is complexed in the chiral envirorunent of the protein. Although the oxidant is achiral, it encounters the sulfide in a chiral envirorunent in which the two faces of the sulfide are differentiated. 

Three different types of columns packed with gels of different pore sizes are available. Columns should be selected that are suitable for the molecular weight range of specific samples, as each type has a different exclusion limit (Fig. 6.41, page 215). Bovine serum albumin (BSA), myoglobin, and lysozyme show good peak shapes using only 100 mM of sodium phosphate buffer as an eluent. There is no need to add any salt to the eluent to reduce the ionic interaction between protein and gel. 

FIGURE 7.10 Dependence of the resolution on the sample volume. A preparative Superformance column 1000-200 (bed volume 20 liters) packed with Fractogel END BioSEC (S) (bed height 63 cm) was loaded with 60 ml (top) and 300 ml of a mixture of bovine serum albumin (5 mg/ml), ovalbumin (5 mg/ml), and cytochrome c (3 mg/ml) (bottom) (20 m/VI sodium phosphate buffer, 0.3 M NaCI, pH 7.2 flow rate 100 ml/min corresponding to 19 cm/hr). When the sample volume is 300 ml the separation efficiency for BSA and ovalbumin is similar. Thus the column can be loaded with larger sample volumes, resulting in reasonable separations. 

Extract the drugs and metabolites by diluting 1 ml of serum with 1 ml of 0.1M sodium carbonate buffer (pH of 9). Force the mixture dropwise through the SPE tube previously prepared. 

Much higher asymmetric induction was observed in the two-phase oxidation of simple alkyl aryl and diaryl sulphides296, substituted alkyl aryl sulphides297 and dithioacetals of formaldehyde298 by sodium metaperiodate in the presence of proteins such as bovine serum y-globulin and egg albumin. Optical purities of the sulphoxides so formed ranged between 20 and 85%. 

Tissue Culture Assay. Kogure et al. (48) report a novel tissue culture assay for detecting several types of sodium channel blockers. The mouse neuroblastoma cell line ATCC CCL 131 is grown in RPMI 1640 supplemented with 13.5% fetal bovine serum and 100 pg/ml gentamycin, in an atmosphere of 5% C0 95% air at 37 C. Ninety-six well plates are seeded with 1 x 10 cells in 200 pi of medium containing 1 mM ouabain and 0.075 mM veratridine. Veratridine and ouabain cause neuroblastoma cells to round-up and die. In the presence of sodium channel blockers (e.g., TTXs or STXs), the lethal action of veratridine is obviated and cells retain normal morphology and viability. An important feature of this assay is that a positive test for sodium channel blockers results in normal cell viability. Since bacterial extracts can contain cytotoxic components, this assay offers an advantage over tests that use cell death as an endpoint. The minimum detectable level of TTX is approximately 3 nM, or approximately 1/1000 mouse unit. 

Na Influx Studies. Na influx was monitored according to the procedure of Owen and Villereal (34), with some modifications. Cells were seeded onto 60-mm culture dishes, grown, and serum starved as described for the assays above. The cells were washed with incubation media and incubated in 3 ml of the appropriate agent at 37 C. After incubation the cells were rapidly washed in ice cold 0.1 mM MgCL and extracted with 5% TCA/0.5% KNO3 for sodium determination or 0.2% SDS for protein determination. Sodium concentration was measured using a Varian Model 275 Atomic Absorption Spectrophotometer. Protein was determined fluorimetrically. 

Sodium and Potassium. For the electrolytes, sodium and potassium the flame pho meter is the instrument of choice (29). This instrument permits readily the dilution of the serum 200 fold, for analysis, using an internal lithium standard. Most instruments require 1 ml for analysis. It is therefore practicable to measure out 3pi and dilute it to 1 ml. This is best done with a sampler-diluter of high precision. The tip of the diluter needs to be a drawn out polyethylene tip, or the 5 pi will not be measured with any degree of accuracy. 

At present, calcium and magnesium are estimated almost exclusively by atomic absorption (36). Present instrumentation permits the dilution of the specimen to approximately 1 - 100 for calcium and even higher for magnesium. For many instruments, the two elements are not read out simultaneously such as is practicable for sodium and potassium with the flame photometer. The lower limit of serum volime at present, for the practical assay for calciim and magnesiim in the laboratory of Neonatology, is approximately 10 ul The instruments are very readily automated, and it is not uncommon for results to be available at the rate of 240 per hour in the routine laboratory, where a typical atomic absorption instrument such as a Perkin-Elmer has been attached to an automatic feed system. 

Sample Collection and Enzyme Stability. Serum samples are collected with chemically clean, sterile glassware. Blood is allowed to clot at room temperature, the clot is gently separated from the test tube with an applicator stick, and the blood is centrifuged for 10 minutes at 1,000 g. If the red cells are known to contain the enzymes whose activity is being measured, as in the case of LD, even slightly hemolyzed serums must be discarded. When acid phosphatase is to be measured, the serum should be placed immediately in ice and processed as soon as possible, or it should be acidified by the addition of a small amount of sodium citrate. Anticoagulants such as EDTA, fluoride and oxalate inhibit some serum enzymes. However, heparin activates serum lipoprotein lipase. 

In the Phadebas TM amylase test (72) (Pharmacia Labs) the substrate was a water insoluble cross-TTnked blue starch in tablet form which also contains some inert ingredients, sodium and potassium phosphate buffer salts and sodium chloride. This polymer was hydrolyzed by amylase into water soluble blue starch fragments. After centrifugation the absorbance of the blue supernatant was proportional to the activity of amylase present in the test samples. The day to day variation on a quality control serum had a coefficient of variation of 2.7% based on 30 days of data in our laboratory. The method is simple, reproducible and uses microquantities of serum. 

Cherry and Crandall in 1932 (86) used olive oil as substrate with gum acacia as the emufsTfier. This method has served as the basis for a number of modifications that increased the stability of the emulsion, decreased incubation time and gave better precision. When a serum sample is incubated with a stabilized olive oil emulsion, lipase acts at the interface of substrate and water to hydrolyze olive oil into fatty acid plus diglycerides, and to a small extent to monoglycerides and glycerol. The bile salt sodium deoxycholate activates the reaction. These methods measure the liberated fatty acids by titration with a standardized NaOH solution. An indicator such as phenolphatalein, thymolphthalein or methyl red or a pH meter are used to detect the end point. 

Roy, A. V. Brown, M. E. and Hayden, J. E. Sodium thymolphthalein monophosphate, a new acid phosphatase substrate with greater specificity for the prostatic enzyme in serum. Clin. Chem. (1971), IJ, 1093-1102. 

Hypertonic sahne is actively excluded from an intact BBB and also acts to draw water into the intravascular space by the creation of a sodium gradient. Various concentrations have been evaluated, with continuous sodium chloride infusions ranging from 3% to 9%, and bolus infusions up to 23.4% administered over 20 minutes in a 30 mL solution. When a continuous infusion is used, the serum sodium is typically titrated to the 155-160 range. Sodium levels above this range raise the concern for seizures and other toxic side effects. Hypertonic saline may hold an advantage over mannitol, as it has been found in animal models to decrease edema in both... 

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