BACKGROUND Nitrous oxide is a commonly used anesthetic that inhibits the activity of methionine synthase, an enzyme involved in methylation reactions and DNA synthesis and repair. This inhibition triggers vacuole formation and degeneration of neurons in areas of the developing and mature brain that are important for spatial memory, raising the possibility that nitrous oxide might have sustained...

Intraoperative recording of myogenic motor potentials evoked by transcranial electrical stimulation (tcMEP) is a method of monitoring the integrity of the vulnerable motor pathways during thoracoabdominal aortic aneurysm (TAAA) surgery. Deflation of the left lung during TAAA surgery may result in impairment of arterial oxygenation. Ventilation with nitrous oxide may cause further desaturation. ...

BACKGROUND Although opioids are unsurpassed analgesics for surgery, they also induce an N-methyl-D-aspartate-dependent enhancement of postoperative hyperalgesia. Because nitrous oxide (N2O) has anti-N-methyl-D-aspartate properties, the purpose of this study was to evaluate nitrous oxide ability to prevent such an opioid-induced hyperalgesia in rats. METHODS First, preventive effects of 50/50%...

BACKGROUND To study the interaction between nitrous oxide and sevoflurane during trachea intubation, the authors determined the minimum alveolar concentration of sevoflurane for tracheal intubation (MAC(TI)) with and without nitrous oxide in children. METHODS Seventy-two children aged 1-7 yr were assigned randomly to receive one of three end-tidal concentrations of nitrous oxide and one of fo...

The retention of nitrous oxide in samples of nitrous oxide in air held in disposable plastic syringes, glass syringes and custom-made nylon film bags was studied by means of gas chromatography at intervals of 90 min, 24, 48 and 120 h after filling the containers. After 24 h the nylon bags retained a mean concentration of 94.5% of the original concentration of nitrous oxide. The disposable plast...

BACKGROUND Exposure to nitrous oxide activates brainstem noradrenergic nuclei and descending inhibitory pathways, which produce the acute antinociceptive action of nitrous oxide. Because corticotropin-releasing factor (CRF) can produce activation of noradrenergic neurons in the locus ceruleus, the authors sought to determine whether it might be responsible for the antinociceptive action of nitr...

BACKGROUND The effect of nitrous oxide on ischemic neuronal damage was quantitatively evaluated by use of logistic regression curves. METHODS Seventy-two gerbils were anesthetized with 1% halothane and randomly assigned to receive 70% nitrous oxide or 70% nitrogen. Forebrain ischemia was performed for 3, 5, or 7 min, and direct-current potential in the hippocampal CA1 region was recorded. His...

Atmospheric nitrous oxide concentrations have been increasing since the industrial revolution and currently account for 6% of total anthropogenic radiative forcing. Microbial production in soils is the dominant nitrous oxide source; this has increased with increasing use of nitrogen fertilizers. However, fertilizer use alone cannot account for the historical trends of atmospheric concentrations...

We have investigated whether nitrous oxide antagonizes or augments the CNS stimulant action of laudanosine in mice by comparing the mean convulsive doses (CD50 (SE] of a control group and those following pretreatment with 65% nitrous oxide in oxygen for 20 and 180 min. Nitrous oxide significantly increased CD50 from 46.8 (1.4) mg kg-1 of control to 57.3 (1.3) mg kg-1 at 20 min and 53.5 (1.7) mg...

ALTHOUGH nitrous oxide is safe when administered by anesthesiologists, misuse may result in brain damage either via asphyxia or via direct effects resulting in vacuole formation in cingulate and retrosplenial cortices under normoxic conditions. The direct toxic effects of nitrous oxide raise the possibility that nitrous oxide toxicity results from excitatory effects of the drug. To determine ho...