Sodium in serum

Gel formation is via ion exchange of sodium in serum for calcium within the alginate dressing. A biodegradable gel is formed when the fiber is in contact with exudate, and the released calcium contributes to the clotting mechanism. The gel may be firm or soft depending upon the proportions of calcium and sodium in the fiber. It is removed with saline. 

EN120 Novros, J., Love, J., Detwiler, R. and Armstrong, D. (1992). Analytical performance of the Kodak Ektachem clinical chemistry slides for measurement of sodium in serum and urine. Clin. Chem. 38, 938-939, Abstr. 16. 

Berry MN, Mazzachi, RD, Pejakovic M, Pealce MJ. Enzymatic determination of sodium in serum. Clin Chem 1988 34 2295-8. 

The unknown may be simply a sodium chloride solution, or it may be serum. If serum is analyzed, then the standards should be prepared over a narrower concentration range to better bracket the unknown. Sodium in serum (approximately 140 meq/L, or 3200 ppm Na) may be determined by simple 1 100 dilution (e.g., 0.1 mL diluted to 10 mL) or 1 500 if required by the instrument. An alternative unknown is an artificial serum prepared by dissolving the following salts in water and diluting to 1 L ... 

Moncrieff, J. Extractionless determination of diclofenac sodium in serum using reversed-phase high-performance liquid chromatography with fluorimetric detection. J.Chromatogr., 1992, 577,185-189 [fluorescence detection harmol (IS) serum column temp 40 LOD 20 n mL]... 

Undiluted samples The activity coefficient of sodium in serum is nearly constant (0.747), as the ion concentrations do not vary much in this system. Sodium ions bound to hydrogen carbonate, protein, etc., escape measurement by ISEs and are not recorded. On the other hand, the measurement is independent of the protein and lipid concentration, i.e., of the variable size of the compartment of macromolecules, that does not contain electrolytes (Figure 1). The relationship between concentration and activity is given by... 

Figure 1 Fractions of sodium in serum. (Modified from Maas AHJ Siggaard-Andersen O, Weisberg HF, and Zijistra WG (1985) Ion-selective electrodes for sodium and potassium a new problem of what is measured and what should be reported. Clinical Chemistry 31 482-485.)...

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. 

The concept of a biocatalytic membrane electrode has been extended to the use of a tissue slice as the catalytic layer. An example of this approach is an electrode for AMP which consists of a slice of rabbit muscle adjacent to an ammonia gas electrode. NHj is produced by enzymatic action of rabbit muscle constituents on AMP The electrode exhibits a linear range of 1.4 x 10 to 1.0 x 10 M with a response time varying from 2.5 to 8.5 min, depending on the concentration. Electrode lifetime is about 28 days when stored between use in buffer with sodium azide to prevent bacterial growth. Excellent selectivity enables AMP to be determined in serum. 

Gold is used therapeutically in chronic inflammations as rheumatic arthritis (Ishida and Orimo 1994). The dose is given in the form ofa gold complex, such as gold sodium thiomalate and Auranofin toxic effects due to overdoses may appear. The most common method to monitor the therapeutic dose in serum or urine is GF-AAS. 

Add 1.6 mEq/L to the measured serum sodium for every 100 mg/dL rise in serum glucose >200 mg/dL ° Calculate free water deficit... 

A greater change in serum sodium may be required if severe signs/symptoms secondary to hyponatremia persist. Another exception may be hyponatremia occurring in the setting after transurethral resection of the prostate (TURP)... 

Serum sodium in acute-onset hypernatremia may be lowered... 

The body s normal daily sodium requirement is 1.0 to 1.5 mEq/kg (80 to 130 mEq, which is 80 to 130 mmol) to maintain a normal serum sodium concentration of 136 to 145 mEq/L (136 to 145 mmol/L).15 Sodium is the predominant cation of the ECF and largely determines ECF volume. Sodium is also the primary factor in establishing the osmotic pressure relationship between the ICF and ECF. All body fluids are in osmotic equilibrium and changes in serum sodium concentration are associated with shifts of water into and out of body fluid compartments. When sodium is added to the intravascular fluid compartment, fluid is pulled intravascularly from the interstitial fluid and the ICF until osmotic balance is restored. As such, a patient s measured sodium level should not be viewed as an index of sodium need because this parameter reflects the balance between total body sodium content and TBW. Disturbances in the sodium level most often represent disturbances of TBW. Sodium imbalances cannot be properly assessed without first assessing the body fluid status. 

Hypertonic hyponatremia is usually associated with significant hyperglycemia. Glucose is an osmotically active agent that leads to an increase in TBW with little change in total body sodium. For every 60 mg/dL (3.33 mmol/L) increase in serum glucose above 200 mg/dL (11.1 mmol/L), the sodium is expected to decrease by approximately 1 mEq/L (1 mmol/L). Appropriate treatment of the hyperglycemia will return the serum sodium to normal.15... 

Although both water and sodium are required in this instance, sodium needs to be provided in excess of water to fully correct this abnormality. As such, hypertonic saline (3% NaCl) is often used. One can estimate the change in serum sodium concentration after 1 L of 3% NaCl infusion using the following equation 16... 

Patient Encounter 5, Estimate the Anticipated Change in Serum Sodium... 

Estimate the anticipated change in serum sodium concentrations after the infusion of 1 L of 3% sodium chloride in a 75-kg male with a serum sodium of 123 mEq/L (123 mmol/L). 

Because disturbances in fluid balance are routinely encountered in clinical medicine, it is essential to have a thorough understanding of body fluid compartments and the therapeutic use of fluids. Similarly, disturbances in serum sodium, potassium, calcium, phosphorus, and magnesium are ubiquitous and must be mastered by all clinicians. Dysregulation of fluid and/or electrolyte status has serious implications regarding the concepts of drug absorption, volumes of distribution, and toxicity. Similarly, many medications can disrupt fluid and/or electrolyte balance as an unintended consequence. 

When diabetic rabbits (24) were treated with 50 IU of bovine insulin imbibed at 50 mg/g poly (acrylic acid) (Figure 14) no reduction in serum glucose over that achieved by the dry blend control could be detected. Pretreatment of the animals with oral doses of either a penetration enhancer, sodium taurocholate, or a protease inhibitor, aproteinin, failed to improve the insulin activity. One possible explanation for this unexpected lack of activity might be that the diseased animals exhibit impaired ileal absorption of fluids (25). 

Wakabayashi et al. [51] determined penicillamine in serum by HPLC. Serum (0.1 mL) was vortex-mixed for 30 s with 50 pL of 0.1% EDTA and 0.2 mL of 10% TCA. The solution was centrifuged at 1500 x g and filtered. A 5 pL portion was analyzed on a Shodex C18 column (15 cm x 4.6 mm i.d.), using a mobile phase of 19 1 methanolic 0.05 M phosphate buffer (pH 2.8) containing 1 mM sodium octylsulfate and 10 pM EDTA. Liver or kidney samples were similarly extracted, and the extracts were cleaned up on a Bond-Elut cartridge prior to HPLC analysis. Detection was effected with an Eicom WE-3G graphite electrode maintained at +0.9 V versus Ag/AgCl. The calibration graph was linear up to 500 ng, and the detection limits were 20 pg. For 1 pg of penicillamine added to serum, liver, or kidney, the respective relative standard deviations (n = 5) were 3.6, 5.1, and 4.4%. 

Symptomatic patients, regardless of fluid status, should initially be treated with either a 0.9% or 3% concentrated saline solution. Resolution of severe symptoms may require only a 5% increase in serum sodium or an initial target serum sodium of 120 mEq/L. 

Several recent determinations of the alkali and alkaline earth metals in serum or urine have been reported. Barrett 29) determined potassium, sodium, and calcium in semm by diluting the samples with lanthanum chloride solution. Suttle and Field 3°) used atomic absorption spectroscopy to determine potassium and magnesium in sheep plasma. 

Table 3 summarizes those elements determined at levels exceeding the physiological concentrations. Bowman 96) determined 0.3 ppm lithium in serum by 1 10 dilution, and by adding sodium and potassium to standards. The concen-... 

Berman u°) could determine as little as 0.005 ppm cadmium in serum and 0.002 ppm in urine by extracting the cadmium from the digest with lead in sodium diethyldithiocarbamate into MIBK. Torres 112) isolated cadmium from urine by ion exchange chromatography. 

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