A patient with hyperthermia, muscle rigidity, rhabdomyolysis, and disseminated intravascular coagulation was initially suspected of taking MDMA (Ecstasy), but toxicology later revealed the presence of MDEA (Eve), a related drug. In vitro testing for malignant hyperthermia was negative.
In seven healthy volunteers, nitrous oxide caused a dose-related impairment of memory, a reduction in tapping frequency, and an increase in inspection time. A paradoxical increase in critical flicker-fusion threshold was observed, but there was no effect on critical fusion-flicker threshold or time sense. Memory tests performed 20 minutes after withdrawal of nitrous oxide showed incomplete recovery, and subjective effects persisted for several hours.
Among over 100,000 adults undergoing general anesthesia for non-cardiac, non-neurosurgical, and non-transplant procedures, low-dose ketamine (0.35 mg/kg or less) given during surgery was associated with a 26% lower odds of postoperative delirium within 7 days compared to no ketamine, with an absolute risk reduction of 0.7%. Higher doses of ketamine did not affect delirium risk. The dose-response relationship was U-shaped, with the lowest delirium risk at cumulative doses of 0.25–0.34 mg/kg.
Xenon at subanaesthetic concentrations produced sedation in healthy male volunteers, with the concentration needed ranging from 27% to 45% (median 35%). Respiratory rate decreased markedly during xenon sedation, but no airway irritability occurred. Eight of ten subjects found xenon sedation pleasant and preferable to nitrous oxide, and one subject required anti-emetic treatment with nitrous oxide compared to none with xenon. The Critical Flicker Fusion test and electroencephalogram parameters did not reliably predict sedation. Xenon was well tolerated with no adverse physiological effects, though subjectively dissimilar to nitrous oxide.