Calculated and Graphically Produced Depth of Anesthesia

There are studies that suggest that unsatisfying levels of anesthesia can cause peri- and postoperative complications in the patient undergoing surgery. Having a unnecessary "deep" anesthesia level can be harmful, causing acute renal failure, injure to myocard, cause delirium and increase the mortality rate. Being too "light", on the other hand, can make the patient experience awareness when muscle relaxant is used. This can lead to serious psychological struggles.

Evaluating the depth of anesthesia is the most important task of the anesthesia team, but can be difficult because clinical signs depend on many factors. In addition to clinical evaluation, EEG is commonly used for interpreting the level of anesthesia in todays practice. Unfortunately, this method is not always accurate and has a delay.

New devices are now developed to calculate the anesthesia level based on the drugs given. The level is simultaneously presented graphically on screen. The purpose of this study is to investigate and compare clinical parameters within patients undergoing general anesthesia, with and without the use of such devices. Hemodynamic stability, less use of adrenergics, higher EEG-levels, a more rapid wake-up and shorter time in post operative care can indicate a more precise level of anesthesia, hence, promote patient safety.