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BACKGROUND Remifentanil-induced secondary hyperalgesia has been documented experimentally in both animals and healthy human volunteers, but never clinically. This study tested the hypotheses that increased pain sensitivity assessed by periincisional allodynia and hyperalgesia can occur after relatively large-dose intraoperative remifentanil and that(More)
Reported effect-site concentrations of propofol at loss of consciousness and recovery of consciousness vary widely. Thus, no single concentration based on a population average will prove optimal for individual patients. We therefore tested the hypothesis that individual propofol effect-site concentrations at loss and return of consciousness are similar.(More)
Cognitive performance in postsurgical patients may be impaired by disturbances of normal circadian rhythm analogous to those produced by rapid transmeridian travel ("jet lag"). We therefore tested the hypothesis that isoflurane anesthesia alone produces a phase-delay in the human circadian temperature rhythm. We monitored central body temperature rhythms(More)
BACKGROUND In-vitro studies indicate that platelet function and the coagulation cascade are impaired by hypothermia. However, the extent to which perioperative hypothermia influences bleeding during surgery remains unknown. Accordingly, we tested the hypothesis that mild hypothermia increases blood loss and allogeneic transfusion requirements during hip(More)
THE combination of anesthetic-induced impairment of thermoregulatory control and exposure to a cool operating room environment makes most surgical patients hypothermic. Several prospective, randomized trials have demonstrated various hypothermia-induced complications. There is no widely accepted definition for the term mild hypothermia. Furthermore, the(More)
Propofol is often used for sedation during regional anesthesia. We tested the hypothesis that propofol blood concentration, the Bispectral Index and the 95% spectral edge frequency predict suppression of learning during propofol/epidural anesthesia in volunteers. In addition, we tested the hypothesis that the Bispectral Index is linearly related to propofol(More)
UNLABELLED Anesthesia and surgery induce macrophage aggregation and neutrophil influx, responses that characterize an inflammatory reaction in the distal airway. We thus evaluated the time-dependent expression of genes for proinflammatory cytokines during propofol and isoflurane anesthesia. We studied patients anesthetized with propofol (n = 20) or(More)
BACKGROUND Nitrous oxide is commonly used in general anaesthesia but concerns exist that it might increase perioperative cardiovascular risk. We aimed to gather evidence to establish whether nitrous oxide affects perioperative cardiovascular risk. METHODS We did an international, randomised, assessor-blinded trial in patients aged at least 45 years with(More)
Experimental evidence and clinical experience suggest that mild hypothermia protects numerous tissues from damage during ischemic insult. However, the extent to which hypothermia becomes a valued therapeutic option will depend on the clinician's ability to rapidly reduce core body temperature and safely maintain hypothermia. To date, general anesthesia is(More)
We measured afterdrop and peripheral tissue temperature distribution in eight patients cooled to approximately 17°C during cardiopulmonary bypass and subsequently rewarmed to 36.5°C. A nasopharyngeal probe evaluated trunk and head temperature and heat content. Peripheral tissue temperature (arm and leg temperature) and heat content were estimated using(More)