Anesthesiology
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Randomized Controlled Trial
Cerebral oxygen saturation measured by near-infrared spectroscopy and jugular venous bulb oxygen saturation during arthroscopic shoulder surgery in beach chair position under sevoflurane-nitrous oxide or propofol-remifentanil anesthesia.
We examined the effects of different anesthetics on cerebral oxygenation and systemic hemodynamics in patients undergoing surgery in beach chair position (BCP). Jugular venous bulb oxygen saturation (SjvO2) and regional cerebral tissue oxygen saturation (SctO2) were determined while patients were placed from the supine to BCP. Whether SctO2 and SjvO2 are interchangeable in assessing the cerebral oxygenation was also examined. ⋯ The margin of safety against impaired cerebral oxygenation is greater and SjvO2 is more preserved with S/N than with P/R anesthesia. SctO2 may not be reliable in detecting a low SjvO2 during the surgery in BCP.
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Comparative Study
Intracranial self-stimulation of the paraventricular nucleus of the hypothalamus: increased faciliation by morphine compared to cocaine.
Neuropathic pain attenuates opioid facilitation of rewarding electrical stimulation of limbic dopaminergic pathways originating from the ventral tegmental area. Whether neuropathic pain alters opioid effects of other brain-reward systems is unknown. ⋯ PVN ICSS is facilitated to a greater extent by morphine than cocaine, and the effects of each drug on this behavior are unaltered after spinal nerve ligation. These effects contrast those observed with direct stimulation of limbic dopamine pathways, suggesting that the PVN may have a greater role in the reinforcing effects of opioids than classic limbic regions, particularly in the presence of chronic pain.
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In some cases of severe preeclampsia/eclampsia, brain imaging displays signs compatible with raised intracranial pressure. We aimed to estimate the incidence of raised intracranial pressure in preeclampsia using ocular ultrasonography. ⋯ In about 20% of preeclamptic patients, ONSD reaches values compatible with intracranial pressure above 20 mmHg. Further work is needed to confirm this incidence and to better understand the diagnostic and therapeutic usefulness of this easy-to-do monitoring technique.