Die Definitionen der Schockformen

Der hypovolamische Schock ist ein Zustand unzureichender Durchblutung vitaler Organe mit konsekutivem Missverhaltnis von Sauerstoff-Angebot und -Verbrauch infolge intravasalen Volumenmangels mit kritisch verminderter kardialer Vorlast; er wird in vier spezielle Formen unterteilt (hamorrhagischer Schock, hypovolamischer Schock im engeren Sinne, traumatisch-hamorrhagischer Schock und traumatisch-hypovolamischer Schock). Der kardiogene Schock ist durch eine primare, kritische Verminderung der kardialen Pumpleistung mit konsekutiver inadaquater Sauerstoff-Versorgung der Organe bedingt. Der anaphylaktische Schock ist eine akute Verteilungstorung des Blutvolumens im Sinn des distributiven Schocks…

Säure-Basen-Status gelagerter und gewaschener Erythrozyten

Überprüfung der Präzision von Kapnometern

Capnometry, i.e. measurement of CO2 concentration (cCO2, vol%) and calculation of the respective CO2 partial pressure (pCO2, mmHg), is simple to apply, but the user must understand its principles of operation in order to appreciate its power and its limitations. However, sidestream capnometers use to dry the humidified respired gas (37 degrees C, pH2O 47 mmHg) for methodological reasons, thus increasing pCO2 by ca. 6% which, in turn, requires correction. With infrared spectroscopy, overestimation of pCO2 in presence of N2O and underreporting of pCO2 in presence of O2 also require to be corrected. These require either knowledge of the respective gas concentrations (mainstream analyzers) or a…

Protective effects of plasma replacement fluids on erythrocytes exposed to mechanical stress

Haemoglobin release from 40 suspensions of packed red blood cells in modified fluid gelatin, 4% albumin solution, 6% hydroxyethyl starch and normal saline was investigated in vitro during circulation with a roller pump from a heart-lung machine for 120 min at a flow rate of 2.5 l.min-1 at room temperature. The lowest haemoglobin release was obtained with erythrocytes in modified fluid gelatin, whereas free haemoglobin concentrations became progressively higher with albumin, hydroxyethyl starch and normal saline [median free haemoglobin (interquartile range) after 120 min circulation: gelatin 493 (360-601) mg.l-1, albumin 692 (590-1111) mg.l-1, hydroxyethyl starch 1121 (692-1518) mg.l-1, nor…

Base Excess and Lactate Concentration in Infusion Solutions and Blood Products

[Physiology and clinical relevance of hyperoxygenation].

Milchsäure-Bildung und Verteilung in Erythrozytenkonzentraten

Alkaline haematin D-575, a new tool for the determination of haemoglobin as an alternative to the cyanhaemiglobin method. I. description of the method

A new method for the rapid and accurate measurement of haemoglobin has been developed as an alternative to the conventional cyanhaemiglobin method. This method is based on the conversion of all haeme, haemoglobin, and haemiglobin species into a stable end product by an alkaline solution of a non-ionic detergent ('AHD reagent'). The reaction product, designated as alkaline haematin D-575, is extremely stable and shows a characteristic absorption peak at 575 nm. As compared to the cyanhaemiglobin method, the determination of haemoglobin by alkaline haematin D-575 offers several advantages such as (1) extreme stability of the AHD reagent and the conversion product, (2) decreased conversion tim…

Alteration of anion gap during almost total plasma replacement with synthetic colloids in piglets

In ten piglets (body weight 8.2-11.6 kg), acid base, electrolyte and anion gap changes were investigated during almost total plasma replacement with hydroxyethyl starch (HES) and modified fluid gelatin (GEL) in saline solution using a cell saver autotransfusion technique. During the study, there were only moderate acid base changes, but marked disturbances in anion balance. At study end, the mean chloride concentration was significantly higher (mmol/l: normal values 97-108, HES 116 +/- 1.5, GEL 108 +/- 1.1, p0.01) and the mean anion gap was significantly lower in the HES group in comparison to the GEL group (mmol/l: normal values 5-14, HES 3 +/- 1.7, GEL 11.9 +/- 0.9, p0.01). It is conclude…

Therapeutische Grenzwerte der akuten, arteriellen Hypoxie

Nichtinvasive Messung der zerebralen Hämoglobin-Sauerstoff-Sättigung

Association between plasma ionized calcium and lactate concentration

ISE are not suitable for the measurement of ionized calcium under clinical conditions when anions like acetate, lactate or malate are present in concentrations of about 5–10 mmol/l.

Die Definitionen der Schockformen - mehr als eine Fleißarbeit?

Optimale und kritische Hämoglobinkonzentration beim Intensivpatienten – aus pathophysiologischer Sicht

Als Ergebnis einer kritischen Analyse theoretischer Uberlegungen, experimenteller Befunde und klinischer Erfahrungen bezuglich einer optimalen oder kritischen Hamoglobinkonzentration eines Intensivpatienten wird ein Optimalwert von 10±2 g/dl vorgestellt, der als Folge einer Hamodilution, welcher Ursache auch immer, keiner Korrektur durch Hamotherapie bedarf. Eine Transfusion von Erythrozyten im Hb-Konzentrationsbereich von 7 bis 10 g/dl macht eine Begrundung erforderlich, d.h. die Transfusion ist nur bei nachgewiesenen Symptomen einer generellen oder lokalen Hypoxie gerechtfertigt. Diese Angaben gelten fur einen normoxischen, normovolamischen und normothermen Patienten.

Die Sauerstoff-Abgabe menschlicher Erythrocyten unter Hyperoxie

Die Sauerstoff-Abgabe menschlicher Erythrocyten wurde sowohl in Ruhe als auch in schneller Stromung (Platte-Kegel-Viscosimeter) nach Sattigung mit unterschiedlichen Sauerstoffpartialdrucken von 50–600 mm Hg gemessen. Unter diesen experimentellen Bedingungen erreicht die Sauerstoff-Abgabe einen Maximalwert, der fur ruhende Erythrocyten bei einem initialen Sauerstoffpartialdruck von etwa 300 mmHg liegt und fur Erythrocyten in schneller Stromung bei einem initialen Sauerstoffpartialdruck von 100 bis 200 mmHg. Aus diesen Befunden wird der Schlus gezogen, das nur das gleichzeitige Zusammenwirken aller vier, an der Sauerstoff-Abgabe beteiligter Mechanismen, namlich intracellulare Diffusion und Ko…

Diagnostik der O2-Versorgung über den O2-Status des Blutes

Microrheology of erythrocytes and platelets: physiological basis and consequences for the design and the operation of extracorporeal circulatory devices

Publisher Summary This chapter discusses the physiological basis and consequences for the design and the operation of extracorporeal circulatory devices. The microrheological response of erythrocytes and thrombocytes can be observed microscopically under simplified flow conditions in the rheoscope. In this device, cells are observed at high magnifications while being subjected to quantifiable shear stresses. Despite the unphysiological environment, the use of this method allowed an important extrapolation to well-established in vivo flow properties and a clear distinction between the primarily passive microrheological properties of the erythrocytes and the microrheological features of throm…

Pulmonal Oxygen Reservoir - Physiology and Clinical Benefit

O2-Löslichkeit in Fluorocarbonen

Fur zwei der zur Zeit gebrauchlichsten Fluorocarbone, Perfluortributylamin (FC 43, 3M Comp.) und Perfluortetrahydrobutylfuran (FC 75, 3M Comp.), wurden die O2-Loslichkeitskoeffizienten bei Temperaturen von 10 bis 50°C nach Aquilibrierung mit Gasen bekannten Sauerstoffpartialdruckes im manometrischen Apparat nach Van Slyke ermittelt. Die Ergebnisse von 300 Bestimmungen zeigen, das das Henry-Daltonsche Gesetz fur die O2-Loslichkeit in FC 43 und FC 75 nicht erfullt ist. Die Meswerte werden zur Konstruktion von zwei Nomogrammen verwendet, die es erlauben, bei bekanntem O2-Partialdruck und bekannter Temperatur die O2-Konzentration der Fluorocarbone direkt in Volumenprozent abzulesen sowie den Bu…

Pathophysiology of Hypovolemic Shock

[Compensation mechanisms of perioperative anemia].

Physiologische Erythrozyten-Protektionslösung (PEP)

Die korrekte Bestimmung des Base Excess (BE, mmol/l) im Blut

Qualitätskontrolle des Base Excess (BE, mmol/l) im Blutgasanalysator

Diagnostische und therapeutische Bedeutung von Base Excess und Laktatkonzentration

Sauerstoff-Versorgung und Säure-Basen-Status bei extremer Anämie

Die nicht-invasive Messung der mittleren zerebralen O2-Sättigung des Hämoglobins

Sauerstoffversorgung trotz Atemstillstandes

Der Einfluß von exogenem Laktat auf gemessene Plasmalaktatspiegel im hämorrhagischen Schock — eine kontrollierte Studie am Schwein

Einleitung: Seit mehr als 40 Jahren wird Laktat den Kristalloid-Losungen als Anion zugesetzt und als Plasmasubstitut in Form des Ringer-Laktats weltweit eingesetzt. Zur Beurteilung einer anaeroben Stoffwechselsituation und als prognostischer Parameter kommt dem Plasmalaktatspiegel klinisch eine wichtige Bedeutung zu.

Tumor tissue oxygenation as evaluated by computerized-po2-histography

A computerized pO2 measurement system with a novel electrode motion pattern (Sigma-pO2-histography) was evaluated in vitro and in vivo. The system was found to be reliable in 0.9% saline and 10% hydroxyethylene starch solution and in fresh donor blood. Marked deviations were found in lipid and hemoglobin solutions and in fluorocarbon emulsions. Histograms obtained in rat liver, mouse muscle, and subcutis were similar to previously reported distributions. Direct comparison between Sigma-Eppendorf and self-constructed Whalen-type electrodes in hypoxic tumors gave similar results. A large series of measurements indicated that hypoxic and anoxic tissue areas were frequently found both in isogra…

Deklarierung von Infusionslösungen mit Base Excess (BE) und potentiellem Base Excess (BEpot)

Solubility of NH3 and apparent pK of NH4+ in human plasma, isotonic salt solutions and water at 37 degrees C.

The solubility of ammonia, alphaNH3 (mM/mmHg), was determined at 37 degrees C and low ammonia partial pressure (0.02-1 mmHg) in pure water (n =24) as 46.70+/-0.40; aqueous isotonic salt solutions (n = 7) as 46.8+/-0.81; and human plasma (n = 5) as 42.0+/-0.66. The last figure increases to 45.3+/-0.63 if expressed in molal units (mmol/kg plasma water x mmHg) instead of molarity with respect to the water content of the plasma (mean from four healthy and fasting donors: 0.908+0.005 kg H2O/kg plasma; mean density at 37 degrees C: 1.020+/-0.002 kg/l). In pure water, the solubility value is the mean of three different methods: (a) extrapolation of the salting-out effect of ammonia in aqueous NaOH…

Haemoconcentration by gelatin-induced acceleration of erythrocyte sedimentation rate

Erythrocyte sedimentation rates from 40 suspensions of packed red blood cells in modified fluid gelatin, 4% albumin solution, 6% hydroxyethyl starch and normal saline were measured at room temperature using Westergren's method. The erythrocyte sedimentation rate was extremely high in gelatin and this increase was significant after 10-60 min when compared with the other fluids. Erythrocyte sedimentation rates in albumin, hydroxyethyl starch and normal saline were low and there were no differences between these fluids [erythrocyte sedimentation after 60 min, median (interquartile range): gelatin 128 (111.2-130.0) mm, albumin 2 (1.5-2.0) mm, hydroxyethyl starch 1.5 (1.0-1.6) mm, normal saline …

Forderungen und Erwartungen an einen optimalen Volumenersatz

A volume replacement should compensate a reduction in the intravascular volume and counteract a hypovolemia so that hemodynamics and vital functions can be maintained. For this therapy, a physiologically-based solution comprising both osmotically and colloid osmotically active components should be administered. A consensus is proposed for this purpose which takes into consideration the following aspects: The optimum colloid, the questionable use of albumin, the physiological electrolyte pattern encompassing sodium, potassium, chloride and phosphate and their contributions to osmolality, an eventual addition of glucose, the physiological acid-base status with bicarbonate or alternately with …

Lebermetabolismus und Säure-Basen-Haushalt

OXYGEN SOLUBILITY IN NORMAL HUMAN BLOOD

Publisher Summary This chapter describes oxygen solubility in normal human blood. The most crucial problem in measuring physically dissolved oxygen in blood is the prevention of oxygen binding by hemoglobin (Hb). The chapter discusses a study for the re-determination of oxygen solubility in untreated human blood. The oxygen concentration was measured by a photometric method and the Hb-concentration was determined by the cyanohemoglobin method. Oxygen solubility in normal and untreated blood is a linear function of the Hb-concentration. Hemoglobin in the reduced state has a greater influence on oxygen solubility than hemoglobin. Red cell membranes have no measureable effect on the oxygen sol…