[1] F HOFFMANN LA ROCHE & CO LTD,KLIN PRUFUNG & ENTWICKLUNG ABT,GRENZACHERSTR 124,CH-4002 BASEL,SWITZERLAND
[2] CANTONAL UNIV HOSP,INST ANESTHESIOL,CH-1200 GENEVA,SWITZERLAND
[3] UNIV MUNCHEN,CHIRURG POLIKLIN,ANASTHESIEABT,D-8000 MUNCHEN 15,FED REP GER
[4] UNIV GOTTINGEN,ZENTRUM ANASTHESIE,D-3400 GOTTINGEN,FED REP GER
[5] NORTHWESTERN UNIV,SCH MED,CHICAGO,IL 60611
[6] HOP ST ELOI,DEPT ANESTHESIE REANIMAT A,F-34059 MONTPELLIER,FRANCE