Comparative effects of (S)-ketamine and racemic (R/S)-ketamine on psychopathology, state of consciousness and neurocognitive performance in healthy volunteers.

Ketamine and its (S)-enantiomer show distinct psychological effects that are investigated in psychiatric research. Its antidepressant activity may depend on the extent and quality of these psychological effects which may greatly differ between the enantiomers. Previous data indicate that the (S)-ketamine isomer is a more potent anesthetic than (R)-ketamine. In contrast, in subanesthetic doses (R)-ketamine seems to elicit fewer dissociative and psychotomimetic effects compared to (S)-ketamine. In this randomized double-blind placebo-controlled trial the effects of (R/S)-ketamine and (S)-ketamine on standardized neuropsychological and psychopathological measures were compared. After an initial bolus equipotent subanesthetic doses of (R/S)- and (S)-ketamine or placebo were given by continuous intravenous infusion to three groups of 10 healthy male volunteers each (n = 30). (R/S)-Ketamine and (S)-ketamine produced significant psychopathology and neurocognitive impairment compared to placebo. No significant differences were found between (R/S)-ketamine and (S)-ketamine. (S)-Ketamine administration did not result in reduced psychopathological symptomatology compared to (R/S)-ketamine as suggested by previous studies. However, this study revealed a somewhat more "negatively experienced" psychopathology with (S)-ketamine, which opens questions about potential "protective effects" associated with the (R)-enantiomer against some psychotomimetic effects induced by the (S)-enantiomer. As the antidepressant effect of ketamine might depend on a pleasant experience of altered consciousness and perceptions and avoidance of anxiety, the ideal ketamine composition to treat depression should include (R)-ketamine. Moreover, since preclinical data indicate that (R)-ketamine is a more potent and longer acting antidepressant compared to (S)-ketamine and (R/S)-ketamine, randomized controlled trials on (R)-ketamine and comparative studies with (S)-ketamine and (R/S)-ketamine are eagerly awaited.

Educational campaign on stroke in an urban population in Northern Germany: influence on public stroke awareness and knowledge.

BACKGROUND: Public stroke awareness and knowledge may be supportive for stroke prevention and emergency care-seeking behavior after the acute event, which is highly important for early treatment onset. AIMS: In an urban population in Northern Germany (Hannover), a six-month stroke educational campaign was conducted. We expected an increase in stroke knowledge and awareness thereafter. METHODS: Computer-assisted telephone interviews were randomly conducted among 1004 representative participants before and 1010 immediately after the educational multimedia campaign. The computer-assisted telephone interviews focused on questions about stroke knowledge and interventions remembered. RESULTS: Knowledge of stroke risk factors increased during the campaign for overweight, physical inactivity, old age, and stroke in family (P < 0·05). The knowledge of stroke warning signs was low, although it significantly increased during the campaign (P < 0·001) as paresis/weakness (46%) and speech problems (31%) were most frequently named. The majority of respondents indicated that the first action after suffering from stroke should be calling emergency care (74% before vs. 84% after campaign, P < 0·001). CONCLUSIONS: Our data indicate that stroke knowledge and awareness, which could provide earlier presentation to the emergency unit for timely treatment onset, are still low in urban Northern Germany but may decisively be increased by educational campaigns.

Impact of bispectral index monitoring on stress response and propofol consumption in patients undergoing coronary artery bypass surgery.

BACKGROUND: Bispectral Index (BIS)-titrated administration allows a reduction of propofol infusion rates in patients undergoing surgery. Resulting differences in anesthetic depth might affect the stress response to surgery involving neural circuitry not reflected in the electroencephalogram. METHODS: Forty patients scheduled to undergo elective coronary artery bypass grafting receiving a background infusion of remifentanil (0.3 microg . kg . min) were anesthetized with intravenous propofol delivered by target-controlled infusion according to the Marsh pharmacokinetic model under BIS monitoring. In a randomized, prospective design, 20 patients received propofol at a target concentration of 3 microg/ml, whereas in 20 patients propofol was titrated to maintain a BIS value of 40-50. Plasma concentrations of propofol (by means of gas chromatography-mass spectrometry), epinephrine, norepinephrine (by means of high-pressure liquid chromatography), cortisol (by means of radioimmunoassay), and interleukins 6 and 10 (by means of enzyme-linked immunosorbent assay) were measured repeatedly throughout surgery. RESULTS: BIS monitoring allowed a 30% reduction of propofol infusion rates and a similar decrease in plasma propofol concentrations in the BIS group without affecting the stress response to surgery for the group mean. None of the patients reported awareness during a standardized interview. Interestingly, propofol-remifentanil anesthesia blunted the release of epinephrine and cortisol to bypass surgery completely even when the propofol infusion rate was reduced according to BIS values. CONCLUSIONS: Total intravenous anesthesia using propofol-remifentanil effectively attenuates the neurohumoral stress response to coronary bypass surgery involving cardiopulmonary bypass. Titration of propofol using BIS allows for significant reduction of propofol consumption, with only minor effects on stress response under these conditions.

Spinal anesthesia performance conditions and side effects are comparable between the newly designed Ballpen and the Sprotte needle: results of a prospective comparative randomized multicenter study.

UNLABELLED: In this study, we examined the characteristics of a newly designed spinal needle (Ballpen [B]) with a pencil-like tip formed by a stylet that is withdrawn after penetration of the dura. The main goal was to examine whether the use of the B needle could reduce performance time by improved puncture conditions in comparison with the Sprotte (S) needle. Seven-hundred patients at 4 hospitals received single-dose spinal anesthesia with a 25-gauge B or S needle and 0.5% bupivacaine. The performance time of spinal anesthesia was defined as the time between insertion of the introducer needle and the first identification of cerebrospinal fluid in the hub of the spinal needle. Failed spinals were assessed when patients required general anesthesia. On postoperative Day 2-4, all patients were visited and interviewed. Groups did not differ with respect to demographics, puncture site, and dose of bupivacaine. Performance time was 98 +/- 145 s in Group B and 103 +/- 159 s in Group S (P = 0.68). The failure rate in Groups B and S was 3.8% and 3.9%, respectively, and the incidence of postdural puncture headache was 1.8% and 0.9% (P = 0.50), respectively. We conclude that there was no difference in technical variables or outcome between the B and S needles. IMPLICATIONS: This multicenter study examined characteristics of the newly designed Ballpen needle with the Sprotte needle in 700 patients undergoing lower abdominal or extremity surgery in single-dose spinal anesthesia. Technical variables and side effects were comparable between both noncutting spinal needles.