The management of arteriovenous malformations.

Arteriovenous malformations (AVM) can occur in the entire central nervous system with a predilection of the supratentorial intracranial compartment. Intracerebral hemorrhage is the most common clinical presentation of AVM and associated with a high morbidity and mortality rate. Correct management of these lesions is therefore of utmost importance. In this review, the authors present actual diagnostic and interdisciplinary treatment modalities based on their experience in a major neurovascular center and taking into consideration actual literature data. Different treatment strategies are discussed.

Origin of multikilometer earth- and mars-crossing asteroids: A quantitative simulation

Orbital dynamic simulations show that many asteroids in the main asteroid belt are driven toward Mars-crossing orbits by numerous weak mean motion resonances, which slowly increase the orbital ellipticity of the asteroids. In addition, half of the Mars-crossing asteroids (MCAs) transition to Earth-crossing asteroids (ECAs) in less than 20 million years. This scenario quantitatively explains the observed number of large ECAs and MCAs.

Maintenance and recovery characteristics of sevoflurane anaesthesia in adult patients. A multicenter, randomized comparison with isoflurane.

BACKGROUND: The goal of the present multicenter, prospective, randomized clinical investigation was to compare the clinical efficacy and safety of sevoflurane and isoflurane during maintenance of and recovery from general anaesthesia in adult patients. METHODS: With the approval of the Ethical Committee and the patient informed consent, 143 ASA physical status I-II patients, aged 18-65 years, were randomized in order to receive either isoflurane (n = 71) or sevoflurane (n = 72) as the main general anaesthetic. After an oral diazepam (0.1-0.2 mg kg-1) and atropine (0.007-0.01 mg kg-1) premedication and a standardized intravenous induction, general anaesthesia was maintained by adjusting the end-tidal concentrations of the inhalational agent for the maintainance of cardiovascular stability. At the end of surgery the anaesthetic vapours were discontinued, and the neuromuscular block was reversed; the following times were recorded: time of eyes opening, time of command response and suitability for discharge from the recovery area. The occurrence of any untoward event was also recorded. Preoperatively and 24 hr after surgery, blood was collected in order to assess renal an hepatic functions. RESULTS: No differences in demography, duration of surgery, exposure to the inhalational agent and haemodynamic effects were observed between the two groups. Patients receiving sevoflurane showed shorter times for the achievement of extubation (median: 9 min versus 13 min, p = 0.002), eyes opening (median: 10 min versus 13 min, p = 0.002), command response (11 min versus 15 min, p = 0.002) and suitability for discharge from recovery room (median: 19 min versus 22 min, p < 0.05) than those receiving isofluorane. No intra- and intergroup differences were observed in pre- and post-operative laboratory testing of renal and hepatic function. DISCUSSION: We conclude that sevoflurane, when compared to isoflurane, provides a similarly safe maintenance but allows for a more rapid emergence from general anaesthesia.