Intraoperative monitoring in neuroanesthesia: A national comparison between two surveys in Germany in 1991 and 1997

Two surveys initiated by the Neuroanesthesia Research Group of the German S ociety of Anesthesia and Intensive Care Medicine examined the practice of i ntraoperative monitoring during intracranial procedures in Germany in 1991 and 1997. Questionnaires were mailed to departments that were registered me mbers of the German Society of Anesthesia and Intensive Care Medicine and t hat provided neuroanesthesia service on a routine basis in 1991. In 1997, t he survey was repeated in the 1991 respondents. In 1991, 68 departments and in 1997, 44 departments returned completed questionnaires, indicating a re sponse rate of 87% for 1991 and of 65% for 1997. Compared with 1991, the st andards for monitoring, such as surveillance of oxygenation, ventilation, c irculation, and body temperature, were universally applied in adult and ped iatric patients in 1997. Overall, there was a 20% increase in neuromuscular blockade monitoring and in the use of electroencephalography and evoked po tentials in 1997 compared with 1991. Further brain-specific monitoring was rarely provided in 1997. Overall, jugular venous oximetry was used in 20% a nd transcranial Doppler ultrasonography in 15% of responding hospitals. To detect venous air embolism in sitting patients, 75% of all responding hospi tals used precordial Doppler ultrasonography in both years, whereas transes ophageal echocardiography was more often used in 1997 (38%) as compared wit h 1991 (17%).