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At least 19 recordsLinked to original sources
PubMed1988

Mixed venous blood gases are superior to arterial blood gases in assessing acid-base status and oxygenation during acute cardiac tamponade in dogs.

Recent reports using anesthetized ventilator-dependent animal models, have suggested that in certain shock states, a disparity exists between arterial and mixed venous blood gases with regard to acid-base status and oxygenation. In a chronically instrumented unanesthetized canine model of acute cardiac tamponade breathing room air, we studied the effect of a graded decline in cardiac output on arterial and mixed venous pH, PCO2, and PO2. Cardiac tamponade resulted in a profound arterial respiratory alkalosis, whereas mixed venous pH, PCO2, and calculated serum bicarbonate levels remained relatively unchanged. As intrapericardial pressure increased and cardiac output declined, the difference between arterial and mixed venous PCO2 progressively increased. Further, whereas arterial oxygenation improved as cardiac output declined, mixed venous oxygenation steadily worsened. This disparity began early in cardiac tamponade (reductions in cardiac output of 20-40%) long before arterial blood pressure began to fall and progressively worsened as hemodynamic deterioration and lactic acidosis developed. Our findings are consistent with the hypothesis that a reduction in blood flow, resulting in decreased CO2 delivery to the lungs, is the primary mechanism responsible for the difference in pH and PCO2 observed between arterial and mixed venous blood. In this conscious, spontaneously breathing animal model, mixed venous blood gases thus are superior to arterial blood gases in assessing acid-base status and oxygenation, even early in acute cardiac tamponade when the decline in cardiac output is in the range of 20 to 40% and arterial blood pressure has not changed significantly.

Acid-Base Imbalance↗
PubMed1978

Chromatographic analysis of multiple tracer inert gases in the presence of anesthetic gases.

A gas chromatographic method for simultaneous analysis of multiple tracer inert gases in blood and expired gas samples is described. The method enables determination of the distribution of ventilation-perfusion ratios in the lungs during anesthesia with nitrous oxide and halothane. In addition, simultaneous analysis of anesthetic gas concentration in blood permits calculation of the amount of uptake or elimination of anesthetic gases from the Fick principle.

Anesthesia, Inhalation↗
PubMed1998

Electrochemical analysis of clinical blood-gases, gases and vapours.

This tutorial review charts the development of electrochemical sensors for the analysis of blood-gases, gases and vapours in clinical medicine over the past four decades. The development of each sensor is set in its historical and clinical context, and the first part of the review concentrates on aqueous electrolyte electrochemistry and on those sensors which have made a major impact on the clinical measurement of the partial pressures of oxygen and carbon dioxide in the blood. The electrochemical interference effects of anaesthetic agents on these measurements are also described. Those electrochemical sensors which have failed, in the past, to make a clear impact in this area are not considered, but the few attempts to devise aqueous electrolyte electrochemical sensors for anaesthetic agent measurement are reviewed. The second part of the review describes the chequered history of the development of non-aqueous solvent electrochemical sensors to measure the partial pressures of oxygen and carbon dioxide, in both the presence and absence of each other, in the gas phase. The last part of the review examines various attempts, using non-aqueous solvent electrochemistry, to measure the concentration of inhalational anaesthetic vapours in the gas phase. These sensors have yet to make an impact on clinical practice. Throughout this tutorial review, theoretical models of membrane-covered electrochemical sensors are described where appropriate. This review represents a personal view of the development of electrochemical sensors for clinical measurement, and it is therefore necessarily selective in its approach and emphasis.

Anesthetics↗
PubMed1998

[Hazardous material and safety conditions in veterinary practice. 2: Flammable liquid, disinfectants and cleansing media, cytostatics, pressurized gases, liquid nitrogen, narcotic gases, mailing of diagnostic samples, hazardous waste].

In the last years the standards for professional handling of hazardous material as well as health and safety in the veterinary practice became considerably more stringent. This is expressed in various safety regulations, particularly the decree of hazardous material and the legislative directives concerning health and safety at work. In part 1, a definition based on the law for hazardous material was given and the potential risks were mentioned. The correct documentation regarding the protection of personal and the purchase, storage, working conditions and removal of hazardous material was explained. General rules for the handling of hazardous material were described. In part 2, partial emphasis is put on the handling of flammable liquids, disinfectants, cytostatica, pressurised gases, liquid nitrogen, narcotics, mailing of potentially infectious material and safe disposal of hazardous waste. Advice about possible unrecognized hazards and references are also given.

Animals↗
PubMed2000

Greenhouse gases in intensive agriculture: contributions of individual gases to the radiative forcing of the atmosphere

Agriculture plays a major role in the global fluxes of the greenhouse gases carbon dioxide, nitrous oxide, and methane. From 1991 to 1999, we measured gas fluxes and other sources of global warming potential (GWP) in cropped and nearby unmanaged ecosystems. Net GWP (grams of carbon dioxide equivalents per square meter per year) ranged from 110 in our conventional tillage systems to -211 in early successional communities. None of the annual cropping systems provided net mitigation, although soil carbon accumulation in no-till systems came closest to mitigating all other sources of GWP. In all but one ecosystem, nitrous oxide production was the single greatest source of GWP. In the late successional system, GWP was neutral because of significant methane oxidation. These results suggest additional opportunities for lessening the GWP of agronomic systems.

Journal Article↗
PubMed1995

International Federation of Clinical Chemistry (IFCC). Scientific Division. Committee on pH, Blood Gases and Electrolytes. Approved IFCC recommendations on whole blood sampling, transport and storage for simultaneous determination of pH, blood gases and electrolytes.

Pre-analytical variables, e.g., specimen collection, transport, and storage, can contribute significantly to inaccurate pH, blood gas, and electrolyte values. The International Federation of Clinical Chemistry (IFCC), through its Committee on pH, Blood Gases and Electrolytes, has developed specific recommendations to minimize the undesirable effects of pre-analytical variables. The Committee has drawn upon the experiences of its own members as well as published data by others. Specifically, the Committee has included pertinent guidelines and suggestions by the IFCC Working Group on Selective Electrodes (WGSE), the National Committee on Clinical Laboratory Standards (NCCLS), and the Electrolyte/Blood Gas Division of the American Association for Clinical Chemistry (AACC). This paper will familiarize the reader with the effect of different types of specimen containers and anticoagulants. It discusses important aspects of specimen collection procedures including patients status and special precautions during specimen collection from indwelling catheters or cannulae. The paper also identifies different requirements in storage and transport of specimens for blood gas and electrolyte analysis.

Anticoagulants↗