The ideal oxygen/nitrous oxide fresh gas flow sequence with the Anesthesia Delivery Unit machine

2007 ◽  
Vol 19 (4) ◽  
pp. 274-279 ◽  
Author(s):  
Jan F.A. Hendrickx ◽  
Sara Cardinael ◽  
Rik Carette ◽  
Hendrikus J.M. Lemmens ◽  
Andre M. De Wolf
Keyword(s):  
Nitrous Oxide ◽  
Gas Flow ◽  
Oxygen Nitrous Oxide ◽  
Delivery Unit ◽  
The Ideal

Effect of N2O on Sevoflurane Vaporizer Settings during Minimal- and Low-flow Anesthesia

2002 ◽  
Vol 97 (2) ◽  
pp. 400-404 ◽  
Author(s):  
Jan F. A. Hendrickx ◽  
José Coddens ◽  
Frederik Callebaut ◽  
Hermes Artico ◽  
Thierry Deloof ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Gas Flow ◽  
Low Flow ◽  
Oxide Mixture ◽  
Factors Affecting ◽  
Carrier Gas ◽  
Dial Setting ◽  
Oxygen Nitrous Oxide ◽  
Low Flow Anesthesia ◽  
Almost All

Background Uptake of a second gas of a delivered gas mixture decreases the amount of carrier gas and potent inhaled anesthetic leaving the circle system through the pop-off valve. The authors hypothesized that the vaporizer settings required to maintain constant end-expired sevoflurane concentration (Etsevo) during minimal-flow anesthesia (MFA, fresh gas flow of 0.5 l/min) or low-flow anesthesia (LFA, fresh gas flow of 1 l/min) would be lower when sevoflurane is used in oxygen-nitrous oxide than in oxygen. Methods Fifty-six patients receiving general anesthesia were randomly assigned to one of four groups (n = 14 each), depending on the carrier gas and fresh gas flow used: group Ox.5 l (oxygen, MFA), group NOx.5 l (oxygen-nitrous oxide, MFA after 10 min high fresh gas flow), group Ox1 l (oxygen, LFA), and group NOx1 l (oxygen-nitrous oxide, LFA after 10 min high fresh gas flow). The vaporizer dial settings required to maintain Etsevo at 1.3% were compared between groups. Results Vaporizer settings were higher in group Ox.5 l than in groups NOx.5 l, Ox1 l, and NOx1 l; vaporizer settings were higher in group NOx.5 l than in group NOx1 l between 23 and 47 min, and vaporizer settings did not differ between groups Ox1 l and NOx1 l. Conclusions When using oxygen-nitrous oxide as the carrier gas, less gas and vapor are wasted through the pop-off valve than when 100% oxygen is used. During MFA with an oxygen-nitrous oxide mixture, when almost all of the delivered oxygen and nitrous oxide is taken up by the patient, the vaporizer dial setting required to maintain a constant Etsevo is lower than when 100% oxygen is used. With higher fresh gas flows (LFA), this effect of nitrous oxide becomes insignificant, presumably because the proportion of excess gas leaving the pop-off valve relative to the amount taken up by the patient increases. However, other unexplored factors affecting gas kinetics in a circle system may contribute to our observations.

Continuous measurement of gas uptake and elimination in anesthetized patients using an extractable marker gas

2004 ◽  
Vol 97 (3) ◽  
pp. 960-966 ◽  
Author(s):  
Gavin J. B. Robinson ◽  
Philip J. Peyton ◽  
David Terry ◽  
Shiva Malekzadeh ◽  
Bruce Thompson
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Gas Flow ◽  
Continuous Measurement ◽  
Nitrogen Excretion ◽  
Gas Mixture ◽  
Colonic Surgery ◽  
Gas Uptake ◽  
Accuracy And Precision ◽  
Oxygen Nitrous Oxide

Measurement of pulmonary gas uptake and elimination is often performed, using nitrogen as marker gas to measure gas flow, by applying the Haldane transformation. Because of the inability to measure nitrogen with conventional equipment, measurement is difficult during inhalational anesthesia. A new method is described, which is compatible with any inspired gas mixture, in which fresh gas and exhaust gas flows are measured using carbon dioxide as an extractable marker gas. A system was tested in eight patients undergoing colonic surgery for automated measurement of uptake of oxygen, nitrous oxide, isoflurane, and elimination of carbon dioxide with this method. Its accuracy and precision were compared with simultaneous measurements made with the Haldane transformation and corrected for predicted nitrogen excretion by the lungs. Good agreement was obtained for measurement of uptake or elimination of all gases studied. Mean bias was −0.003 l/min for both oxygen and nitrous oxide uptake, −0.0002 l/min for isoflurane uptake, and 0.003 l/min for carbon dioxide elimination. Limits of agreement lay within 30% of the mean uptake rate for nitrous oxide, within 15% for oxygen, within 10% for isoflurane, and within 5% for carbon dioxide. The extractable marker gas method allows accurate and continuous measurement of gas uptake and elimination in an anesthetic breathing system with any inspired gas mixture.

scholarly journals Halothane anaesthesia of normal and dystrophic hamsters

1975 ◽  
Vol 9 (4) ◽  
pp. 345-352 ◽  
Author(s):  
J. E. Carvell ◽  
P. J. Stoward
Keyword(s):  
Nitrous Oxide ◽  
Gas Flow ◽  
Face Mask ◽  
Open Circuit ◽  
Dystrophic Muscle ◽  
Oxide Mixture ◽  
Oxygen Nitrous Oxide ◽  
Wet Weight ◽  
Clear Plastic ◽  
Anaesthetic Mixture

Induction, carried out in a small clear-plastic box with 3·5% (v/v) halothane in 30:70 (v/v) oxygen: nitrous oxide, was quiet and rapid. Recovery was almost instantaneous. 2% halothane in the oxygen-nitrous oxide mixture was sufficient for maintenance anaesthesia. The anaesthetic mixture was given by face mask in an open circuit specially designed to function at low gas-flow rates. The halothane content of the muscle and blood after 25 min anaesthesia was estimated by gas chromatography of n-heptane extracts. The mean level(± s.e.m.) in blood was 22·8±2·7 mg/1OO ml (n=4), and in dystrophic muscle 226±36·8 mg/100 g wet weight of tissue (n=4): there was a positive correlation (r=0·94) between them ( p<:0·02).

scholarly journals Chronic pain relief after the exposure of nitrous oxide during dental treatment: longitudinal retrospective study

2015 ◽  
Vol 73 (7) ◽  
pp. 578-581 ◽  
Author(s):  
Francisco Moreira Mattos Júnior ◽  
Rafael Villanova Mattos ◽  
Manoel Jacobsen Teixeira ◽  
Silvia Regina Dowgan Tesseroli de Siqueira ◽  
Jose Tadeu Tesseroli de Siqueira
Keyword(s):  
Chronic Pain ◽  
Nitrous Oxide ◽  
Dental Treatment ◽  
Chronic Pain Patients ◽  
Before And After ◽  
Nitrous Oxide Oxygen ◽  
Oxygen Nitrous Oxide ◽  
Prevalence Of Pain ◽  
Underlying Mechanisms ◽  
Pain Patients

The objective was to investigate the effect of nitrous/oxygen in chronic pain. Seventy-seven chronic pain patients referred to dental treatment with conscious sedation with nitrous oxide/oxygen had their records included in this research. Data were collected regarding the location and intensity of pain by the visual analogue scale before and after the treatment. Statistical analysis was performed comparing pre- and post-treatment findings. It was observed a remarkable decrease in the prevalence of pain in this sample (only 18 patients still had chronic pain, p < 0.001) and in its intensity (p < 0.001). Patients that needed fewer sessions received higher proportions of nitrous oxide/oxygen. Nitrous oxide may be a tool to be used in the treatment of chronic pain, and future prospective studies are necessary to understand the underlying mechanisms and the effect of nitrous oxide/oxygen in patients according to the pain diagnosis and other characteristics.

scholarly journals METODE PERHITUNGAN MASSA GAS CO2 YANG DISERAP FOTOBIOREAKTOR DENGAN PERSAMAAN GAS IDEAL

2016 ◽  
Vol 11 (2) ◽  
pp. 239
Author(s):  
Arif Dwi Santoso
Keyword(s):  
Gas Flow ◽  
Co2 Concentration ◽  
Ideal Gas ◽  
Gas Absorption ◽  
Flow Diagram ◽  
Measuring Instruments ◽  
Continuous Systems ◽  
Co2 Gas ◽  
Method Of Calculation ◽  
The Ideal

BPPT conducted the mass of CO2 gas calculation in the gas absorption experiments with phytoplankton cultivation in the photobioreaktor (FBR) batch and continous syatem using the ideal gas equation. This study stated that the method of calculation with the ideal gas equation is more simple and practical in providing data analysis compared with biomass methods. Some things to note in this method include good knowledge about the movement of the gas flow diagram of inputs and outputs FBR, an appropriate gas sampling, and accuracy of measuring instruments. The required data in the mass calculation of CO2 gas in a batch photobioreactor system was resultant CO2 concentration during measurement. Meanwhile in a continuous systems, the requireddata was CO2 concentration at the reactor input and output , the rate and duration of the injection gas.Keywods : massa gas CO2, dry weight, ideal gas formula

Diffusion of Xenon and Nitrous Oxide into the Bowel

2001 ◽  
Vol 94 (3) ◽  
pp. 475-477 ◽  
Author(s):  
Helmut Reinelt ◽  
Uwe Schirmer ◽  
Thomas Marx ◽  
Pantelis Topalidis ◽  
Michael Schmidt
Keyword(s):  
Nitrous Oxide ◽  
Gas Diffusion ◽  
Control Group ◽  
Nitrogen Diffusion ◽  
Nitrous Oxide Oxygen ◽  
Oxygen Nitrous Oxide ◽  
Median Volume ◽  
Oxygen Group ◽  
Bowel Segments ◽  
To Receive

Background Nitrous oxide diffuses easily from blood into air filled spaces. Xenon is also a relatively insoluble gas, like nitrous oxide. Therefore, the authors measured xenon diffusion into obstructed bowel segments during xenon anesthesia and compared this with nitrous oxide and nitrogen diffusion. Methods Twenty-one pentobarbital-anesthetized pigs were randomly assigned to three groups to receive either xenon-oxygen, nitrous oxide-oxygen, or nitrogen-oxygen (75%-25%), respectively. In each animal four bowel segments of 15-cm length were isolated. A pressure-measuring catheter was inserted into the lumen, and 30 ml of room air was injected into the segments. Anesthesia with the selected gas mixture was performed for 4 h. Pressure in the segments was measured continuously. The volume of gaseous bowel content was measured on completion of the study. Results The median volume of bowel gas in animals breathing nitrous oxide was 88.0 ml as compared with 39.0 ml with xenon anesthesia and 21.5 ml in the nitrogen-oxygen group. After 4 h of anesthesia, the intraluminal pressures in the nitrous oxide group were found to be significantly greater than in the control group and in the xenon group. Conclusions The amount of diffused gas was significantly lower during xenon anesthesia than with nitrous oxide anesthesia but greater than with controls. Blood solubility can therefore be regarded as an important factor influencing gas diffusion into air filled cavities.

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