Safer Surgery part 34. There have been few research investigations into how highly trained doctors and nurses work together to achieve safe and efficient anaesthesia and surgery. While there have been major advances in surgical and anaesthetic procedures, there are still significant risks for patients during operations and adverse events are not unknown. Due to rising concern about patient safety, surgeons and anaesthetists have looked for ways of minimising adverse events. | 304 Safer Surgery anaesthesia is also only partially represented. The specialized field of activity for the anaesthesiologists is thus more realistic than for the other occupation groups. Since the content of the communication is determined by specialist activity in this study we investigated only the anaesthesiologists communication not that of the surgeons or the nursing staff. Anaesthesia simulators like most flight simulators are high fidelity simulators. These offer the advantage of allowing a relatively standardized way of observing how incidents are dealt with. Complete standardization is not possible because the behaviour of the anaesthesiologists influences the further course of the incident. The analysis of such scenarios thus faces the same problems as does problemsolving research with highly complex computer-simulated scenarios see Dörner et al. 1983 . Behaviour in simulator scenarios can already deviate from real operation situations because in calm beginning phases the participants are more prepared for critical events during an operation. Additionally at least at the beginning the participants are aware that they are in an observation situation. For this reason utterances that often occur in calm phases of real operations like jokes lessons and private conversation Pettinari 1988 are rarely heard. Despite these limitations physiologically and as an operation setting for anaesthesiologists the simulator is at least apparently valid. In the scenarios we used cf. Section the anaesthesiologists exhibited a high degree of involvement which was confirmed in self reports St Pierre et al. 2004 . This high degree of the participants involvement during hot phases of the scenario suggests that here they used their customary communication strategies especially to coordinate with the nursing staff and surgeons. Research Questions The study presented here investigated how anaesthesiologists in critical situations in the simulator communicate with their nursing
