THE EFFECT OF NITROUS OXIDE ON THE VOLATILE ANESTHETIC CONCENTRATION WHICH INDUCES ELECTROENCEPHALOGRAPHIC SILENCE

1998 ◽  
Vol 86 (Supplement) ◽  
pp. 352S
Author(s):  
Toshiya KOITABASHI ◽  
Ryoichi OCHIAI ◽  
Yoshio TAKINO ◽  
Junzo TAKEDA
Keyword(s):  
Nitrous Oxide ◽  
Volatile Anesthetic ◽  
Anesthetic Concentration

Interaction of Isoflurane and Nitrous Oxide Combinations Similar for Median Electroencephalographic Frequency and Clinical Anesthesia

1996 ◽  
Vol 84 (4) ◽  
pp. 782-788. ◽  
Author(s):  
Heiko Ropcke ◽  
Helmut Schwilden
Keyword(s):  
Nitrous Oxide ◽  
Minimum Alveolar Concentration ◽  
Dose Range ◽  
Volatile Anesthetic ◽  
Oxide Concentration ◽  
Anesthetic Requirement ◽  
Clinical Anesthesia ◽  
Sparing Effect ◽  
The Relationship ◽  
Nitrous Oxide Concentration

Background The volatile anesthetic sparing effect of nitrous oxide in clinical studies is less than might be expected from the additivity of minimum alveolar concentration values. Other studies identify nonadditive interactions between isoflurane and nitrous oxide. The aim of this study was to quantify the interaction of isoflurane and nitrous oxide at a constant median electroencephalographic frequency. Methods Twenty-five patients were studied during laparotomies. Nitrous oxide was randomly administered in concentrations of 0, 20, 40, 60, and 75 vol%, to ten patients for each nitrous oxide concentration. Isoflurane vaporizer settings were chosen so that the median electroencephalographic frequency was held between 2 and 3 Hz. The relationship between nitrous oxide concentrations and required isoflurane concentrations was examined with the method of isoboles. Results Nitrous oxide linearly decreased the isoflurane requirement. Addition of every 10 vol% of nitrous oxide decreases the isoflurane requirement by approximately 0.04 vol%. The total anesthetic requirement of isoflurane and nitrous oxide, expressed in terms of previously reported minimum alveolar concentration values, increased significantly with increasing nitrous oxide concentrations. Conclusions The interaction of isoflurane and nitrous oxide in the dose range 0-75 vol% on median electroencephalographic frequency is compatible with additivity. The potency of nitrous oxide as a substitute for isoflurane is less than on a minimum alveolar concentration basis. Maintaining median electroencephalographic frequency more appropriately reflects the clinical usage of isoflurane and nitrous oxide than does maintaining minimum alveolar concentration.

scholarly journals Presynaptic and Postsynaptic Effects of the Anesthetics Sevoflurane and Nitrous Oxide in the Human Spinal Cord

2007 ◽  
Vol 107 (4) ◽  
pp. 553-562 ◽  
Author(s):  
Jan H. Baars ◽  
Michael Benzke ◽  
Falk von Dincklage ◽  
Josephine Reiche ◽  
Peter Schlattmann ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Nitrous Oxide ◽  
Presynaptic Inhibition ◽  
Femoral Nerve ◽  
Volatile Anesthetic ◽  
H Reflex ◽  
Receptor Subtype ◽  
Gamma Aminobutyric Acid ◽  
Human Spinal Cord ◽  
Two Parameters

Background Reduced spinal excitability contributes to the suppression of movement responses to noxious stimuli during the anesthetic state. This study examines and compares presynaptic and postsynaptic effects of two anesthetics in the human spinal cord. Methods The authors tested two parameters during the administration of 0.8 vol% sevoflurane or 40 vol% nitrous oxide compared with control states before and after drug administration: (1) the size of the soleus H reflex (integrating presynaptic and postsynaptic effects) at increasing stimulus intensities (recruitment curve) and (2) the amount of presynaptic inhibition on Ia afferents of the quadriceps femoris, evaluated by the heteronymous facilitation of the soleus H reflex caused by a conditioning stimulation of the femoral nerve. The study was performed in 10 subjects for each drug. Results At the chosen concentrations, the maximum H reflex was reduced by 26.3 +/- 8.4% (mean +/- SD) during sevoflurane and by 33.5 +/- 15.6% during nitrous oxide administration. The averaged recruitment curves were similarly depressed under the influence of the two drugs. The reduction of H-reflex facilitation was significantly stronger for sevoflurane (28.8 +/- 20.0%) than for nitrous oxide administration (6.2 +/- 26.4%). Conclusions These results demonstrate in humans presynaptic effects of the volatile anesthetic sevoflurane but not of nitrous oxide. A possible explanation for this difference may be the different potency of the respective drugs in enhancing gamma-aminobutyric acid type A receptor-mediated inhibition, because presynaptic inhibition in the spinal cord involves this receptor subtype.

Prevention of Postoperative Nausea and Vomiting

2018 ◽  
pp. 147-152
Keyword(s):  
Risk Factors ◽  
Nitrous Oxide ◽  
Relative Risk ◽  
Adverse Events ◽  
Postoperative Nausea ◽  
Volatile Anesthetic ◽  
Postoperative Nausea And Vomiting ◽  
Nausea And Vomiting ◽  
Baseline Risk ◽  
Maximum Reduction

This case focuses on the prevention of postoperative nausea and vomiting (PONV) by asking the question: What is the efficacy of six well-established prophylactic antiemetic strategies individually and in combination for the prevention of postoperative nausea and vomiting? Each of the three antiemetics in this study (ondansetron, dexamethasone, and droperidol) reduced the risk for PONV by approximately 26%; substituting propofol for volatile anesthetic reduced the risk by 19%; and substituting nitrogen (air) for nitrous oxide reduced the risk by 12%. A maximum reduction of 70% in the relative risk for PONV can be expected when total intravenous anesthesia is used with three antiemetics. The appropriate approach to the management of PONV depends on the patient’s baseline risk factors as well as the likelihood of adverse events and costs from the antiemetic medications.

scholarly journals Nitrous Oxide Diffusion and the Second Gas Effect on Emergence from Anesthesia

2011 ◽  
Vol 114 (3) ◽  
pp. 596-602 ◽  
Author(s):  
Philip J. Peyton ◽  
Ian Chao ◽  
Laurence Weinberg ◽  
Gavin J. B. Robinson ◽  
Bruce R. Thompson
Keyword(s):  
Nitrous Oxide ◽  
Partial Pressure ◽  
Group Versus ◽  
Volatile Anesthetic ◽  
Control Group ◽  
Oxygen Control ◽  
Volatile Anesthetic Agent ◽  
Eye Opening ◽  
Alveolar Oxygen ◽  
Oxide Group

Background Rapid elimination of nitrous oxide from the lungs at the end of inhalational anesthesia dilutes alveolar oxygen, producing "diffusion hypoxia." A similar dilutional effect on accompanying volatile anesthetic agent has not been evaluated and may impact the speed of emergence. Methods Twenty patients undergoing surgery were randomly assigned to receive an anesthetic maintenance gas mixture of sevoflurane adjusted to bispectral index, in air-oxygen (control group) versus a 2:1 mixture of nitrous oxide-oxygen (nitrous oxide group). After surgery, baseline arterial and tidal gas samples were taken. Patients were ventilated with oxygen, and arterial and tidal gas sampling was repeated at 2 and 5 min. Arterial sampling was repeated 30 min after surgery. Sevoflurane partial pressure was measured in blood by the double headspace equilibration technique and in tidal gas using a calibrated infrared gas analyzer. Time to eye opening and time extubation were recorded. The primary endpoint was the reduction in sevoflurane partial pressures in blood at 2 and 5 min. Results Relative to baseline, arterial sevoflurane partial pressure was 39% higher at 5 min in the control group (P < 0.04) versus the nitrous oxide group. At 30 min the difference was not statistically significant. Time to eye opening (8.7 vs. 10.1 min) and time to extubation (11.0 vs.13.2 min) were shorter in the nitrous oxide group versus the control group (P < 0.04). Conclusions Elimination of nitrous oxide at the end of anesthesia produces a clinically significant acceleration in the reduction of concentrations of the accompanying volatile agents, contributing to the speed of emergence observed after inhalational nitrous oxide anesthetic.

Effects of midazolam and nitrous oxide on the minimum anesthetic concentration of isoflurane in the ball python (Python regius)

2019 ◽  
Vol 46 (6) ◽  
pp. 807-814
Author(s):  
Cédric B. Larouche ◽  
Craig Mosley ◽  
Hugues Beaufrère ◽  
Christopher Dutton
Keyword(s):  
Nitrous Oxide ◽  
Python Regius ◽  
Anesthetic Concentration

scholarly journals A 13-Year-Old Girl in Trigeminy During Anesthesia for Outpatient Dental Surgery: A Case Report

2015 ◽  
Vol 62 (3) ◽  
pp. 110-113 ◽  
Author(s):  
Bryan Neil Waxman
Keyword(s):  
Nitrous Oxide ◽  
Normal Sinus Rhythm ◽  
Volatile Anesthetic ◽  
Intravenous Anesthesia ◽  
Dental Surgery ◽  
Intravenous Cannula ◽  
Normal Sinus ◽  
Dental Rehabilitation ◽  
Initial Rhythm ◽  
Ventricular Dysrhythmias

Abstract A 13-year-old girl presented to a private office for dental rehabilitation under general anesthesia. The patient had a previous uneventful anesthetic 5 years prior in the same office by another dental anesthesiologist. The patient was highly anxious and would not allow monitors placed prior to induction. After an uneventful mask induction with sevoflurane, nitrous oxide, and oxygen, monitors were placed and a 22-gauge intravenous cannula inserted. The initial rhythm on the electrocardiogram was trigeminy interspersed with normal sinus rhythm. The volatile anesthetic sevoflurane was discontinued immediately, and intravenous anesthesia was started but still the patient was consistently entering trigeminy. The patient was always hemodynamically stable and never hypoxic. An in-depth discussion of the case and discussion of ventricular dysrhythmias is presented.

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