Remifentanil-sevoflurane anaesthesia for laparoscopic cholecystectomy: comparison of three dose regimens.

The objective of this study was to determine a dosing regimen for remifentanil-sevoflurane anaesthesia that achieves an optimal balance between quality of anaesthesia and time to recovery. Patients undergoing elective laparoscopic cholecystectomy were randomly allocated to receive 0.4, 0.8 or 1.2 MAC (minimal alveolar concentration) of sevoflurane combined with remifentanil as required to maintain stable anaesthesia. For induction of anaesthesia, the remifentanil dose was 25 microg x kg(-1) x h(-1) and the mean propofol dose which was required to obtain loss of consciousness was 1.59 mg x kg(-1). During the maintenance phase, the mean remifentanil dose was 16.0, 14.1 and 13.0 microg x kg(-1) x h(-1) for the 0.4, 0.8 and 1.2 MAC groups, respectively. The mean sevoflurane maintenance dose was 0.91, 1.24 and 2.1% end-tidal for the 0.4, 0.8 and 1.2 MAC groups, respectively. The incidence of somatic responses was significantly higher in the 0.4 MAC sevoflurane group. Recovery times were significantly faster in the 0.4 compared to the 0.8 and 1.2 MAC groups and in the 0.8 compared to the 1.2 MAC group. The combination of 14 microg x kg(-1) x h(-1) remifentanil and 1.24% end-tidal sevoflurane achieved the optimal balance between the quality, and recovery from anaesthesia.

[Nitrous oxide in anesthesia--present status of the use of nitrous oxide, risks for patients and personnel and treatment of side effects]. / Lachgas in der Anästhesie--Aktueller Stand der Lachgasanwendung, Risiko für Patienten und Personal und Behandlung der Nebenwirkungen.

Mechanisms of some effects of nitrous oxide have recently been elucidated. Its antinociceptive action depends partly on the involvement of the endorphinergic system. Although vitamin B 12 becomes biologically inactive in the presence of nitrous oxide, this certainly is of no clinical consequence in exposures lasting less than eight hours. Should exposures last over 8 hours, effects of vitamin B 12 inactivation can be compensated for by administration of folinic acid. In contrast, professional exposure to trace levels of nitrous oxide seems not to interfere with human health. Furthermore, closed circle apparatus should be used and operating room air be well scavenged when nitrous oxide is used.

One lung high frequency ventilation for peroral sealing of bronchial stump fistulae.

The use of high frequency ventilation for 28 repairs of bronchial stump fistulae with fibrin sealant is discussed. Intravenous anaesthesia with continuous infusions of methohexitone, alfentanil and suxamethonium was employed. This method of anaesthesia and ventilation proved to be satisfactory.

Effects of gonadectomy and exogenous gonadal steroids on sex differences in open field behaviour of adult rats.

Two experiments were carried out to investigate the contribution of gonadal hormones to the expression of sex differences in open field behaviour of adult female and male rats. In the first experiment rats were gonadectomized or sham-operated in adulthood and tested in the open field 1, 2, 3, 4, 5 or 6 weeks later (3 min/rat on 3 consecutive days during the light period of the day). It was found that following gonadectomy the well known sex difference in ambulation and rearing behaviour (females more than males), as well as in defaecation (females less than males) remained. Ovariectomy caused a decrease in ambulation and rearing, with an increase in defaecation, whereas castration had no significant effect on ambulation and rearing, but also increased defaecation. Also an overall increase in ambulation and rearing was found: animals tested 5 and 6 weeks following the operation were significantly more active than animals tested at 1-4 weeks after the operation. In the second experiment female and male rats were gonadectomized and 7 weeks later they received a silastic implant containing testosterone (T), dihydrotestosterone (DHT), oestradiol (E2), DHT plus E2, or nothing (control condition). Four weeks after the implantation the animals were tested in the open field (3 min/rat on 3 consecutive days). An overall sex difference was found for ambulation (females more than males) and for defaecation (females less than males). The only effect of hormone administration was found in DHT-treated animals: lowest ambulation and highest defaecation compared to other hormone and control animals. No differences were found between the T, E2, DHT plus E2, and control animals. From these data it was concluded that endogenous gonadal steroids seem to play a minor role in the expression of sex differences in adult open field behaviour in the rat.