We have investigated, in volunteers, the effect of inhaling 50% nitrous oxide in oxygen on subsequent oxygenation. Subjects breathed either 50% nitrous oxide in oxygen or 50% nitrogen in oxygen during hyperventilation and normal ventilation. Arterial oxygen saturation and end-expired oxygen concentrations were lower after 50% nitrous oxide in oxygen than after the other mixture with both patter...

Background. Funicular myelosis is a known consequence of exposure to nitrous oxide. Nevertheless, there are only a few clinical trials assessing its long-term effects and there is no literature about the role of nutritional vitamin B12 supplementation in the context of nitrous oxide abuse. Case Descriptions. We diagnosed funicular myelosis in a young butcher, who consumed high amounts of meat r...

We studied 88 healthy, ASA I patients (aged 20-45 yr), to determine if nitrous oxide affects thiopentone requirements for achieving 50% probability of no movement in response to verbal commands (CP,50). Patients were allocated randomly to one of four nitrous oxide concentration groups (0%, 20%, 40% and 60%). Patients in each group were also allocated randomly to receive predetermined target pla...

Administration of nitrous oxide is useful for providing sedation and analgesia. The therapeutic range for nitrous oxide is 20-30%. Several oxygen treatment devices have been used for administering nitrous oxide, but little is known about the concentrations of nitrous oxide and oxygen delivered to the trachea. We have studied this, using an analogue lung model, with several oxygen therapy device...

The effects of nitrous oxide alone and combination of nitrous oxide and fentanyl on spinal reflexes were studied in cats with transected spinal cord at the thoracic level. Nitrous oxide 33, 50 and 75% in oxygen depressed the amplitude of monosynaptic reflexes in a dose-dependent manner, but exerted little effect on polysynaptic reflexes. The addition of fentanyl 2.5 microgram kg-1 during the ad...

The effect of nitrous oxide on the growth of two types of ascites tumour in mice was investigated. The mice in the first two trials were injected with tumour cells, divided into three groups and exposed to one of the following atmospheres: (1) air; (2) 25% nitrous oxide; (3) 40% nitrous oxide. After treatment, the volume of ascites fluid and the concentration of cells were measured. It was foun...

We have studied the cardiovascular effects of nitrous oxide after cardiac ischaemia-reperfusion injury caused by aortic cross-clamping and unclamping during coronary artery bypass grafting (CABG). At the time of chest closure, 20 patients were allocated randomly to receive oxygen and air (FIO2 = 0.5) or 50% nitrous oxide in oxygen in addition to anaesthesia with fentanyl. Nitrous oxide signific...

The effects of nitrous oxide on the early explanted chick embryo were investigated using the technique of New (1955). After 22 hours incubation the embryos were explanted and exposed for a further 24 hours to the following gases: air, nitrous oxide (25 per cent), nitrous oxide (60 per cent), nitrous oxide (79 per cent). The oxygen concentration was maintained at normal levels (20.9 per cent) an...

OBJECTIVE To determine whether treatment with midazolam or with nitrous oxide is more efficient in facilitating intravenous (IV) access in lean and obese children and adolescents. DESIGN A prospective, double-blind, randomized trial of 90 children and adolescents. SETTING Astrid Lindgrens Children's Hospital, Karolinska University Hospital, Stockholm, Sweden. Patients A total of 60 obese ch...

BACKGROUND AND OBJECTIVES Nitrous oxide is the most widely used inhalational anesthetic worldwide. Its action mechanism is broadly discussed based on results of experimental studies and clinical evidences. The purpose of this study was to evaluate, through specific monitoring, nitrous oxide electrophysiological action on the central nervous system. METHODS Twenty-five patients of both genders...