The analgesic activities of a 75:25% nitrous oxide-oxygen mixture administered for 15 min, of delta-9-tetrahydrocannabinol (THC) 10 mg kg-1 i.p., and of a combination of both, were evaluated in the rat by tail-flick and hot-plate tests. The nitrous oxide-oxygen mixture produced a significant increase in the pain threshold. The analgesic activity of THC was similar in extent but of longer durati...

Diffusion anoxia. By Bernard Raymond Fink. Anesthesiology 1955; 16:511-14. In 1955, Dr. Bernard Raymond Fink published his findings that described the mechanism by which hypoxemia occurred when nitrous oxide-oxygen anesthesia was discontinued and room air breathing commenced. Using an ear oximeter and brachial artery blood gases, he measured oxygen saturation in eight healthy patients who had r...

In the last few years, the emission of nitrous oxide from wastewater treatment plants has become a topic of increased interest, given its considerable impact on the overall climate footprint of wastewater treatment plants. Various sampling strategies to estimate nitrous oxide emission from wastewater treatment plants have been applied in different studies. The present study addresses the influe...

A modification of the Haldane technique, using potassium hydroxide as the absorbent, was devised to measure the concentration of carbon dioxide in the presence of nitrous oxide. It depends upon the principle that the amount of nitrous oxide absorbed is proportional to the duration of its exposure to the reagent. If the absorption of carbon dioxide from the gas mixture is completed within a fixe...

The effect of halothane and nitrous oxide on the capacity of natural killer (NK) lymphocytes from female patients with benign and malignant breast disease to kill the tumour cell line K562, was studied in vitro. There was no depression of activity of NK lymphocytes when exposed to 2% halothane and 66% nitrous oxide either alone or in combination. However, NK lymphocyte activity was depressed at...

Blood pressure and cerebrospinal fluid pressure changes were studied during lumbar air encephalography under general anaesthesia. Two anaesthetic techniques were used. In one group spontaneous respiration with nitrous oxide, oxygen and halothane was used and in the other controlled ventilation with nitrous oxide and oxygen was maintained. Larger falls in blood pressure, on sitting up, were seen...

The phenomenon of diffusion hypoxia is commonly believed to occur unless nitrous oxide-oxygen inhalation sedation is followed by "washout" with 100% oxygen for 5 minutes upon termination of the flow of nitrous oxide. When systematically studied, however, this phenomenon generally appears to be unfounded. The present study evaluated the effect of breathing room air instead of 100% oxygen in heal...

Methane and nitrous oxide emissions from a fully covered municipal wastewater treatment plant were measured on-line during 16 months. At the plant under study, nitrous oxide contributed three-quarters to the plant's carbon footprint, while the methane emission was slightly larger than the indirect carbon dioxide emission related to the plant's electricity and natural gas consumption. This contr...

Entrainment of air following exploration of posterior cranial fossa in the sitting position was studied in five patients. Intracranial pressure was monitored through a ventriculostomy catheter after closure of the dura. In three patients nitrous oxide was added to the breathing mixture only after the baseline intracranial pressure had stabilised following closure of the dura. A marked rise in i...

In nine patients with severe intracranial disease causing increased intracranial pressure (ICP), the effects on ICP and cerebral perfusion pressure (CPP) of the following manoeuvres were studied: (1) endotracheal intubation, (2) addition of 50% nitrous oxide to the inspired gas after hyperventilation with oxygen and thereafter (3) addition of halothane to the nitrous oxide/oxygen mixture. The m...