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H F Weisberg

Publications and source records attributed to H F Weisberg.

18 recordsLinked to original sources
PubMed1990

International Federation of Clinical Chemistry (IFCC). Scientific Division. Committee on pH, Blood Gases and Electrolytes. Guidelines for transcutaneous pO2 and pCO2 measurement.

This document provides guidelines in the terminology, methodology, and in the interpretation of data obtained from the use of skin (transcutaneous) pO2 and pCO2 electrodes. The transcutaneous technique has found special application in newborn infants. The causes of analytical bias with respect to arterial blood gas values and imprecision obtained with transcutaneous pO2 and pCO2 electrodes are reviewed. Electrode temperatures above 44 degrees C should not be used routinely, and at a measuring temperature of 44 degrees C, the measuring site should be changed at least every 4 h to avoid skin burning.

Blood Gas Monitoring, Transcutaneous↗
PubMed1990

Guidelines for transcutaneous p O2 and p CO2 measurement.

This document provides guidelines in the terminology, methodology, and in the interpretation of data obtained from the use of skin (transcutaneous) p O2 and p CO2 electrodes. The transcutaneous technique has found special application for newborn infants. The causes of analytical bias with respect to arterial blood gas values and imprecision obtained with transcutaneous p O2 and p CO2 electrodes are reviewed. Electrode temperatures above 44 degrees C should not be used routinely, and, at a measuring temperature of 44 degrees C, the measuring site should be changed at least every 4 h to avoid skin burning.

Blood Gas Monitoring, Transcutaneous↗
PubMed1990

International Federation of Clinical Chemistry (IFCC). Scientific Division. Committee on pH, Blood Gases and Electrolytes. Guidelines for transcutaneous PO2 and PCO2 measurement.

This document provides guidelines in the terminology, methodology, and in the interpretation of data obtained from the use of skin (transcutaneous) P02 and PCO2 electrodes. The transcutaneous technique has found special application in newborn infants. The causes of analytical bias with respect to arterial blood gas values and imprecision obtained with transcutaneous P02 and PCO2 electrodes are reviewed. Electrode temperatures above 44 degrees C should not be used routinely, and, at a measuring temperature of 44 degrees C, the measuring site should be changed at least every 4 hours to avoid skin burning.

Bias↗
PubMed1989

IFCC document stage 3, draft 1, dated 1989 02 01. An approved IFCC recommendation. IFCC method (1988) for tonometry of blood: reference materials for pCO2 and pO2. International Federation of Clinical Chemistry Scientific Division. Committee on pH, Blood Gases and Electrolytes.

A reference method for tonometry of blood is described. The document covers the theory of tonometry, the materials and equipment needed, and essential aspects of the tonometry procedure for blood. The partial pressures of oxygen and carbon dioxide in tonometered blood are accurately known and therefore this blood is recommended for assessing the accuracy of blood gas analyzers. Tonometry of blood samples from patients may also be used in the determination of acid-base quantities and hemoglobin-oxygen affinity, e.g. p50.

Blood Gas Analysis↗
PubMed1989

International Federation of Clinical Chemistry (IFCC), Scientific Division. Committee on pH. Blood Gases and Electrolytes. IFCC method (1988) for tonometry of blood: reference materials for pCO2 and pO2.

A reference method for tonometry of blood is described. The document covers the theory of tonometry, the materials and equipment needed, and essential aspects of the tonometry procedure for blood. The partial pressures of oxygen and carbon dioxide in tonometered blood are accurately known and therefore this blood is recommended for assessing the accuracy of blood gas analyzers. Tonometry of blood samples from patients may also be used in the determination of acid-base quantities and hemoglobin-oxygen affinity e.g. p50.

Blood Gas Analysis↗
PubMed1985

Ion-selective electrodes for sodium and potassium: a new problem of what is measured and what should be reported.

For clinical purposes the activities of Na+ and K+ obtained with ion-selective electrodes in undiluted whole blood or serum should be multiplied by an appropriate factor to obtain the same values as the substance concentrations obtained by flame photometry. The factor is primarily dependent on the mass concentration of water in normal plasma divided by the molal activity coefficient of Na+ (or K+) of normal plasma. We discuss the value of the molal activity coefficient of Na+ obtained by theoretical calculations and by direct measurement. The discrepancies between theory and measurement (gamma Na+ of 0.747 and 0.73, respectively) may be due to some binding of Na+ (protein binding or ion pair formation), a small and variable residual liquid-junction potential, or certainty about the appropriate value for the ionic strength of normal plasma (0.16 mol/kg or somewhat higher).

Electrodes↗
PubMed1984

Quality control of electrolyte analyzers. Evaluation of the anion gap average.

The authors have shown previously that averaging at least eight patient anion gaps provides a sensitive technic for the detection of systematic error in electrolyte analysis (Am J Clin Pathol 79:688-696, 1983). They conducted a retrospective and prospective evaluation of this technic on the ASTRA 4. One month of patient and control data were studied retrospectively and showed that 17/71 abnormally low patient anion gap averages were associated with violations in a multi-rule procedure, and 41/71 low averages were associated with violations in cusum, a more sensitive procedure. In the prospective study, a total of 36 runs of eight patient specimens with low anion gap averages (less than 7.5 mmol/L) were reanalyzed after appropriate recalibration and/or maintenance. Thirty-one of the 36 groups had significant changes in either Na (nine groups, delta Na = +1.5 mmol/L), Cl (14 groups; delta Cl = -1.8 mmol/L), or in both Na and Cl (eight groups; delta Na = +1.2 mmol/L; delta Cl = -0.9 mmol/L). Because the average error detected was small, the authors recommend that the average of anion gaps be used as an early indicator of drift. It must be used, however, in conjunction with standard quality control procedures such as the multi-rule approach.

Acid-Base Equilibrium↗
PubMedDate not supplied

Osmotic pressure of the serum proteins.

The osmotic pressure of the serum proteins (colloid osmotic pressure [COP] or "oncotic" pressure) is only one of the four Starling forces (plus the capillary permeability coefficient) which affect the net filtration of fluid from the capillaries. The COP will vary with the concentration of total serum proteins, but more so with the specific pattern or composition of the protein components, especially albumin. The use of formulas utilizing total protein (or albumin/globulin) to calculate COP is not warranted. COP should be determined; this is easy at the present time with the advent of a compact commercial instrument. Generalized or localized edema (e.g., pulmonary edema or ascites) has been associated with low serum albumin and low COP values. This is not always so since cases of analbuminemia do not necessarily exhibit edema. The study of COP is warranted but precautions are necessary in proper interpretation of the causes of "edema,"--the Starling forces and hemodynamic factors, capillary permeability, lymphatic return, etc., are all involved in the phenomenon.

Ascites↗
PubMedDate not supplied

Pathogenesis of gallstones.

The three lipids in bile, cholesterol, lecithin, and bile salts (about 90 percent of the dry weight of normal gallbladder bile) are amphipathic substances having both hydrophobic and hydrophilic functional groups. Knowledge of the physicochemical factors of gallstone formation (especially cholesterol stones) has increased in the past two decades. The absolute amount of cholesterol supersaturation determines the extent of cholesterol precipitation. The ionic strength of the bile and the types of bile salts present are minor factors, whereas the ratios of bile salts to lecithin at a particular concentration of total lipids are the major factors contributing to gallstone production. Bile acids (salts) form micelles which allow the lecithin and cholesterol to dissolve within the micelles. Thus the administration of bile acids allows for non-invasive dissolution of some cholesterol gallstones. Additional important risk factors are genetic and ethnic, sex (females predominate), obesity, diet (in contrast to animal protein and more refined carbohydrate diets, there is less lithogenicity with diets containing plant protein and unrefined carbohydrates), certain diseases, and drug therapy. Pigment stones make up the majority of radiopaque stones and are predominant in the Orient; they are seen in certain diseases and in infections of the biliary tree.

Animals↗
PubMedDate not supplied

Evaluation of nutritional status.

The assessment of nutritional status has become very popular, especially for patients undergoing stress (surgery) or potential parenteral nutrition. Evaluation of cancer patients is essentially the same as for other patients. Body fat reserves are approximated by subcutaneous skinfold measurements. Somatic protein (skeletal muscle) mass is decreased in marasmus (protein-calorie malnutrition) and is evaluated by anthropometric determinations, based upon age and sex or both. Instead of using relatively inadequate standards such as the 1959 Metropolitan Life Insurance tables for ideal weight, it is advocated to use the population percentiles derived from the Health and Nutritional Examination Survey (HANES) published in 1979. The visceral protein mass is decreased in kwashiorkor and is approximated by study of the liver transport proteins. A mixed-type of protein-calorie malnutrition may exist, e.g., cancer cachexia, with marked decrease of immunocompetence. A prognostic nutritional index, based on biologic measurements rather than true nutritional assessment, can predict the probability of complications and survival in severely ill patients. All such studies should be used to substantiate good clinical judgement, based on adequate history and physical examination with emphasis on the nutritional aspects.

Body Height↗