Carbon-mineral sorbents successfully combine a high mechanical resistance of the mineral matrix and a high activity of carbons. It is possible to prepare a mineral matrix of the wanted structure and use it as the basis for producing carbon-mineral sorbents. SUMS-1 and SUMS-2 are the sorbents of mild action. In ...

The purpose of this review is to provide information about the technical solutions behind the Datex Deltatrac Metabolic Monitor. Deltatrac measures oxygen consumption (VO2), carbon dioxide production (VCO2) and calculates from those respiratory quotient (RQ = VCO2/VO2) and energy expenditure (EE). Deltatrac can monitor both mechanically ventilated and spontaneously breathing ...

1. The ventilatory sensitivity to CO2 obtained from a non-steady-state step-ramp CO2 challenge (analogous to the Read rebreathing method) was compared with the one of the steady-state method. 2. Experiments were performed during normoxia on twenty cats anaesthetized with chloralose-urethane. In eight of these cats additional measurements were carried out ...

The potential advantages of carbon dioxide over room air to insufflate the bowel during colonoscopy include its nonexplosive nature and rapid absorption. To evaluate whether this rapid absorption would minimize any reduction in colonic blood flow resulting from the distention, we measured inferior mesenteric artery flow before, during, and after ...

The role of carbonic anhydrase in chicken embryo blood acid-base balance was examined using the carbonic anhydrase inhibitor acetazolamide during the second half of incubation. Day 13, 16, and 17 embryos of treated eggs had significant increases in blood PCO2 and decreases in blood pH when compared with controls.

Three methods (IL-182 Co-Oximeter, IL-282 Co-Oximeter, and headspace gas chromatography) for the analysis of carbon monoxide in postmortem blood were studied and compared using a prepared reference standard, Quantra control materials, and 62 postmortem blood specimens. The methods compared favorably with one another. The linear regression equations for the 62 ...

Fetal carbon dioxide tension during labour is elevated in both metabolic and respiratory acidosis, but intermittent fetal blood analyses often fail to detect PCO2 changes during acute complications. Transcutaneous carbon dioxide monitoring is continuous and the possibility of diagnosing PCO2 changes is therefore better. The theoretical background for transcutaneous measurements ...

The insufflation of oxygen at 1 litre kg-1 min-1 via two endobronchial catheters (called continuous flow ventilation (CFV)) maintained a normal PaCO2 and a constant PaO2 in anaesthetized paralysed dogs and in five out of seven cats. In two cats with a high carbon dioxide production, CFV failed to maintain ...

Ablation of atrioventricular conduction is now widely accepted in the management of supraventricular arrhythmias. Reports of high temperatures, high pressures, and gas production suggest that there may be adverse effects on the blood, the electrode, and the cardiovascular system. In this investigation, using samples of fresh, heparinized pig blood, we ...

Ten dogs were given a primed infusion of H13CO3- for 220 min while under general anesthesia. Isotopic steady state was reached within 60 min in exhaled CO2, femoral arterial blood HCO3-, and femoral venous blood HCO3-. Halfway through each infusion study, the site of tracer infusion was changed either from ...

Uterine specimens specially prepared for extracorporeal perfusions (arterial and venous stumps available for catheterization) were perfused with oxygenated Krebs-Ringer bicarbonate-glucose buffer for periods of up to 12 hours to investigate the feasibility of obtaining constant flow, stability of biochemical parameters, and adequate distribution of the perfusion fluid. Flow rates of ...

We studied factors influencing urine pCO2 minus blood pCO2 [(U-B)pCO2] in rabbits infused with sodium bicarbonate solutions. Unlike other species, the rabbit does not develop a significant (U-B)pCO2 (urine pCO2 greater than blood pCO2) after alkali or acid buffer infusion. However, intravenous acetazolamide immediately induced a significant (U-B)pCO2. The effect ...

Eleven incidents of carbon monoxide (CO) intoxication resulting in sixteen fatalities are reported. All of the cases involved heating systems as either the source or the means of distributing the CO. Blood samples were analyzed for ethanol and CO. Elevated blood CO saturations were found in 14 of the 16 ...

Respiratory function in the restrained, conscious domestic fowl was measured using a non-invasive technique and computer aided analysis to examine respiratory flow, and in-dwelling arterial catheters to monitor blood carbon dioxide levels. The effects of two low ranges of inspiratory carbon dioxide (0.2 to 1.0 per cent and 0.25 to ...

The study was undertaken to determine the effects of running a marathon on concentration of various blood components resulting from phenomena other than fluid loss, and these were related to performance times. Twenty male marathon runners ranging from 20 to 50 years of age participated in the study. Blood samples ...

The value of the continuous monitoring of end-tidal carbon dioxide concentration as an indicator of the acute intraoperative interruption of pulmonary blood flow, in patients with pre-existing restrictions of pulmonary blood flow undergoing closed heart surgery, is illustrated by two case reports. Decreases in end-tidal carbon dioxide concentration often appeared ...

Studies of arterialized capillary blood gases and acid-base values were performed on 712 normal persons who were between the ages of 29 days and 24 years. The results were divided for clinical use into six groups by age; linear regression lines were constructed for better understanding of the development of ...

The stability of carbon monoxide (CO) in blood was studied under various conditions of storage using both spectrophotometric and gas chromatographic-flame ionization detector (GC-FID) methods of analysis. Changes (losses) in percent carbon monoxide saturation occurred under some conditions but not under others. Various mechanisms for CO losses are considered and ...

For those clinical laboratories equipped with a microprocessor-controlled gas analyser, an extremely simple method is described for the determination of the total carbon dioxide content in various biological fluids. Since this method needs only 20 microL of blood plasma or is less dependent on the original total carbon dioxide content, ...

The values of effective permeability (Krogh's diffusion coefficient) for carbon dioxide have been measured in horizontal stationary layers of whole blood and hemoglobin solutions in quasi-steady state, with the goal of understanding the specific nature of facilitated diffusion of carbon dioxide occurring in these media. The average partial pressure of ...

Variations in cerebral blood flow and partial pressures of oxygen and carbon dioxide (pO2, pCO2) were studied in rabbits during short-duration (1 min) immobilization stress. The techniques used enabled us to determine these variables locally in the caudate nucleus in a continuous, simultaneous and quantitative fashion. It could be shown ...

The current method for determining blood carboxyhemoglobin concentration by gaschromatography has been critically evaluated and compared to spectrophotometric analysis methods. The major sources of bias in the method accuracy have been found to be in the measurement of blood volume and in the separate determination of total hemoglobin concentration in ...

Branchial gas transfer, acid-base balance, and hemodynamics were critically evaluated and compared in Ringer-perfused and blood-perfused heads of rainbow trout. Blood perfusion stimulated O2 uptake and CO2 excretion across the gills to values more representative of intact fish. The stimulatory effect of blood on gas transfer was due to increased ...

Branchial ionic transport processes were evaluated and compared in Ringer-perfused and blood-perfused heads of rainbow trout. Rates of Na+ and Cl- influx were similar to in vivo levels at the onset of perfusion. Na+ uptake deteriorated more rapidly over time during Ringer perfusion, whereas Cl- uptake was relatively stable regardless ...

Spirometric measurements of vital capacity and flow rates, thoracic gas volume, and single-breath diffusing capacity for carbon monoxide were obtained in 360 white women, 238 wives age 58 years and 122 daughters age 32 years of shipyard workers from the Long Beach area of southern California. The values for nonsmokers, ...

The steady state ventilatory response to inhaled CO2 was measured in eleven unanesthetized premature Macaca nemestrina during the first 3 wk of life in different steady state background O2 mixtures hypoxia (FIO2 = 0.08 or 0.12), normoxia (FIO2 = 0.21) and hyperoxia (FIO2 = 0.96). Hyperoxic delta VI/delta PACO2 and ...

Cerebral venous outflow and carbon dioxide transients were studied during five different transitional states: (1) on and off 10% carbon dioxide breathing, (2) on and off hyperventilation, (3) on 7% carbon dioxide breathing, (4) on 10% carbon dioxide breathing initiated from 7% carbon dioxide breathing, and (5) on 10% carbon ...

Carbon dioxide production was measured in 20 adult patients undergoing alloplastic operation of the hip. Body weight ranged from 40 to 81 kg. Anaesthesia consisted of lumbar plexus block, i.v. diazepam, pethidine, pavulon and N2O/O2 under controlled ventilation. CO2 production was 2.13 ml kg-1 min-1 (interquartile range 2.09-2.23). A fresh ...

The carbon dioxide laser has recently received clinical acceptance in neurosurgical practice. There are, however, few studies reported in the neurosurgical literature, either clinical or experimental, concerning its safety or efficacy on a physiological level by comparison to a more conventional tool. This study is not a description of a ...

Eggshell porosity affects the metabolism and growth of the developing embryo and is likely, therefore, to influence blood-gas and acid-base status. PO2 in the airspace and in blood from the allantoic vein, PCO2 in the airspace and in blood from the allantoic artery and allantoic vein, and pH of blood ...

Acetazolamide, which reversibly inhibits carbonic anhydrase, is a useful diuretic in alkalotic and over-hydrated patients. In two earlier investigations we have consistently found increases in the arterial and venous oxygen saturation and tension when patients were treated with acetazolamide 15 mg . kg-1. A plausible explanation of this phenomenon is ...

A self-calibrating fully automatic instrument for the measurement of oxygen consumption, carbon dioxide production and the respiratory quotient of mechanically ventilated patients has been developed. The instrument is based on commercially available conventional oxygen and carbon dioxide gas analysers and a domestic natural gas volumetric flow meter. The distribution of ...

Local blood flow, and partial pressures of oxygen and carbon dioxide were directly monitored in the vulnerable region of Ammon's horn (e.g. CA3) of unanaesthetized, freely breathing rats in which epileptic seizures of 120 min duration were induced by parenteral kainic acid. Blood flow was periodically determined by helium clearance. ...

The use of carbonic anhydrase inhibitors (CAIs) was associated with mean increases in whole-blood zinc levels of 82 micrograms/dL and 70 micrograms/dL, respectively, in a cross-sectional survey and in a prospective study of patients with glaucoma. The time course of the increase suggests that CAIs induce reticulocyte synthesis of carbonic ...

Blood in mouth, nose, and eye tissues of birds cools by evaporation, then flows to a cephalic vascular heat exchanger, the ophthalmic rete. There, acting as a heat sink, blood from the evaporative surfaces cools arterial blood flowing counter-current to it toward the brain. The brain thus remains cooler than ...

Right-to-left shunting decreases the efficiency of carbon dioxide excretion and increases the alveolar dead space (physiological dead space minus anatomical dead space). The theoretical effects of shunting on alveolar dead space were studied, using a human blood nomogram, for different values of inspired oxygen fraction (FIO2), respiratory quotient (R), and ...

The effect of cerebral carbonic anhydrase inhibition on the DC potential difference between cerebrospinal fluid (CSF) and blood (PD) was studied in anesthetized dogs by perfusing the ventriculocisternal system with artificial CSF containing the carbonic anhydrase inhibitor, acetazolamide. The slope of the PD vs. arterial blood pH (delta PD/delta pHa) ...

The effects of topical application of the carbonic anhydrase inhibitor trifluormethazolamide (TFM) on intraocular pressure (IOP), ascorbate and CO2 concentrations in aqueous humor, and aqueous humor flow were studied in rabbits. These effects were compared with those produced by systemic treatment with methazolamide. The decrease in IOP observed after TFM ...

Carbon dioxide dissociation curves of oxygenated and deoxygenated bloods, the Haldane effect, the buffer value and other blood and true plasma buffering indices, O2 capacity and hematocrit were determined in bloods withdrawn from chicks before, during and after hatching and 8-month-old hens. Blood CO2 dissociation curves shifted upwards in the ...

The relative effects of temperature and CO2 on the blood flow in the common carotid artery (CCBF) were investigated in vagotomized, paralyzed rabbits under urethane-chloralose general anaesthesia with artificial ventilation. During hypothermia a 52% fall of CCBF was observed in rabbits ventilated by the classic method. Administration of a hyperkapnic ...

When exposed to hypoxia, intact mice, with elevated blood ketones, live longer than mice with normal blood ketones. To evaluate a possible mechanism responsible for this phenomenon a rat brain slice preparation was used to determine if brain tissue would utilize glucose or ketones preferentially during exposure to reduced oxygen. ...

The Bain circuit was studied in a model lung on the assumption that, in addition to the ratio of fresh gas flow to total ventilation (VFG/VE), different time fractions of the respiratory cycle might influence rebreathing. We found that the time fraction for active expiration (FEt) governed rebreathing for each ...

An in vivo autoradiographic strategy is described for the measurement of local cerebral blood flow in humans by positron emission tomography, based on an application of the single-compartment model originally proposed by Kety. A variety of factors are considered upon which the successful quantitation of local blood flow depends. These ...

Using noninvasive measurement of cranial blood flow, we previously demonstrated that full-term asphyxiated neonates have decreased cerebral perfusion that can persist up to 5 days of age. In an attempt to test their postischemic cerebrovascular CO2 reactivity, we measured cranial blood flow in ten asphyxiated term (39 +/- 0.8 weeks ...

The performance of three electrodes used for transcutaneous carbon dioxide (tcPCO2) monitoring is compared in 15 healthy volunteers and 26 critically ill adults. All three electrodes showed good correlation between tcPCO2 and arterial blood PCO2 (PaCO2) with a correlation coefficient (r) greater than 0.86. There was little difference in the ...

Protons and carbon dioxide are physiological regulators for the oxygen affinity of hemoglobin. The heterotropic allosteric interaction between the non-heme ligands and oxygen, collectively called the Bohr effect, facilitates not only the transport of oxygen but also the exchange of carbon dioxide. Several types of interactions can be thermodynamically formulated. ...

We examined the tracer wash-in technique for measuring blood flow for a specific experimental model in which medullary chemoreceptor blood flow is estimated using carbon dioxide as the tracer. Using a mathematical model, we calculated the flow values that would be estimated when blood flow is a function of the ...

The paper is concerned with materials characterizing physicochemical properties of haemosorbents of varying grades. Adsorption of different uraemic toxins was studied. The possibility of microembolization of internal organs and tissues with haemosorbent particles was explored in the course of prolonged treatment with the use of haemosorption. Different approaches to connecting ...

Two alternative mechanisms have been proposed for tubular reabsorption of bicarbonate: (a) H+ secretion and CO2 reabsorption and (b) direct reabsorption of HCO-3. In an attempt to differentiate between the two mechanisms, the present study utilized the natural abundance of stable carbon isotopes (13C, 12C) in the urinary total CO2. ...

Toxic irreversible encephalopathic syndromes developed in 2 patients treated with lithium carbonate and haloperidol. Symptoms consisted of lethargy, fever, tremulousness, confusion, and extrapyramidal and cerebellar dysfunction, accompanied by leucocytosis and elevated serum enzyme, blood urea nitrogen, creatinine and fasting blood glucose levels. One patient suffered widespread irreversible brain damage; the ...