Medical Technology Assessment

Update on bispectral index monitoring

Since 1997, bispectral index (BIS; Aspect Medical Systems Inc., Natick, MA) has been in clinical practice and a wealth of experimental research has accumulated on its use. Originally, the device was approved only for monitoring hypnosis and has now received an indication for reducing the incidence of intraoperative awareness during anesthesia. Numerous studies have documented the ability of BIS to reduce intermediate outcomes such as hypnotic drug administration, extubation time, postoperative nausea and shortened recovery room discharge. Two recent large-scale outcome studies using BIS (one randomized controlled trial and one prospective, nonrandomized historical cohort study) identified an approximately 80% reduction in the incidence of recall after anesthesia. BIS provides clinicians with unique information that can be used to tailor hypnotic drug doses to individual patient requirements. BIS does not predict movement or hemodynamic response to stimulation, nor will it predict the exact moment consciousness returns. This review will also discuss other BIS applications including use in pediatrics, intensive care and for procedural sedation. Some limitations exist to the use of BIS and it is not useful for some individual hypnotic agents (ketamine, dexmedetomidine, nitrous oxide, xenon, opioids). BIS technology is moving out of the operating room and into diverse environments where conscious and deep sedation are provided. Anesthesiologists need to be actively involved in promoting patient safety and helping transition this technology into broader use.

Patient satisfaction with anaesthesia care: What is patient satisfaction, how should it be measured, and what is the evidence for assuring high patient satisfaction?

Patient satisfaction is a part of outcome quality. Many theories of satisfaction include patients' expectation. One definition of satisfaction is therefore the degree of congruence between expectation and accomplishment. The involvement of patients as well as experts is therefore an important step in the development of an instrument to measure patient satisfaction. Results of single-item ratings or overall satisfaction surveys are over-optimistic and do not represent the true indication of care. The construction of highly standardized (psychometric) questionnaires should include elements of content validity, criterion and construct validity, reliability and practicability. Based on the few available studies in anaesthesia, patient satisfaction is primarily determined by information and communication. There is great potential for improvement in this area. However, we do not know the best way to continuously improve patient satisfaction with anaesthesia care, or to what extent decisions should be shared between the anaesthetist and the patient.

Outcomes in perioperative medicine and anesthesiology. Into the next millennium

Although the development of outcomes research in perioperative medicine and anesthesiology has focused on traditional clinical outcomes, there seems to be a transition toward more global assessments of patient-related outcomes. Present trends in outcomes research and EBM may promise an improvement in individual patient and overall quality of care. New roles and opportunities in perioperative medicine and anesthesiology provide additional venues for outcomes research in this millennium.