Methodologic Considerations for Collecting Patient-reported Outcomes from Unselected Surgical Patients.

Background: The impact of surgery on health is only appreciated long after hospital discharge. Furthermore, patients' perceptions of postoperative health are not routinely ascertained. The authors instituted the Systematic Assessment and Targeted Improvement of Services Following Yearlong Surgical Outcomes Surveys (SATISFY-SOS) registry to evaluate patients' postoperative health based on patient-reported outcomes (PROs).

Psychological sequelae of surgery in a prospective cohort of patients from three intraoperative awareness prevention trials.

Background: Elective surgery can have long-term psychological sequelae, especially for patients who experience intraoperative awareness. However, risk factors, other than awareness, for symptoms of posttraumatic stress disorder (PTSD) after surgery are poorly defined, and practical screening methods have not been applied to a broad population of surgical patients.

Methods: The Psychological Sequelae of Surgery study was a prospective cohort study of patients previously enrolled in the United States and Canada in 3 trials for the prevention of intraoperative awareness.

Postoperative recovery with bispectral index versus anesthetic concentration-guided protocols.

Background: Use of the bispectral index (BIS) monitor has been suggested to decrease excessive anesthetic drug administration, leading to improved recovery from general anesthesia. The purpose of this substudy of the B-Unaware and BAG-RECALL trials was to assess whether a BIS-based anesthetic protocol was superior to an end-tidal anesthetic concentration-based protocol in decreasing recovery time and postoperative complications.

Methods: Patients at high risk for awareness were randomized to either BIS-guided or end-tidal anesthetic concentration-guided general anesthesia in the original trials.

Relationship between bispectral index values and volatile anesthetic concentrations during the maintenance phase of anesthesia in the B-Unaware trial.

Background: Hypnotic depth during anesthesia affects electroencephalography waveforms and electroencephalogram-derived indices, such as the bispectral index (BIS). Titrating anesthetic administration against the BIS assumes reliable relationships between BIS values, electroencephalogram waveforms, and effect site concentration, beyond loss of responsiveness. Associations among BIS, end-tidal anesthetic concentrations (ETAC), and patient characteristics were examined during anesthetic maintenance, using B-Unaware trial data.

Prevention of intraoperative awareness in a high-risk surgical population.

Background: Unintended intraoperative awareness, which occurs when general anesthesia is not achieved or maintained, affects up to 1% of patients at high risk for this complication. We tested the hypothesis that a protocol incorporating the electroencephalogram-derived bispectral index (BIS) is superior to a protocol incorporating standard monitoring of end-tidal anesthetic-agent concentration (ETAC) for the prevention of awareness.

Methods: We conducted a prospective, randomized, evaluator-blinded trial at three medical centers.

Bispectral index monitoring, duration of bispectral index below 45, patient risk factors, and intermediate-term mortality after noncardiac surgery in the B-Unaware Trial.

Background: Postoperative mortality has been associated with cumulative anesthetic duration below an arbitrary processed electroencephalographic threshold (bispectral index [BIS] <45). This substudy of the B-Unaware Trial tested whether cumulative duration of BIS values lower than 45, cumulative anesthetic dose, comorbidities, or intraoperative events were independently associated with postoperative mortality.

Methods: The authors studied 1,473 patients (mean ± SD age, 57.

Association of perioperative risk factors and cumulative duration of low bispectral index with intermediate-term mortality after cardiac surgery in the B-Unaware Trial.

Background: Current data suggest that mortality after noncardiac surgery may be associated with persistent hypotension and the cumulative duration of low processed electroencephalogram-based bispectral index (BIS). This study assessed the relationships among cumulative duration of low BIS (BIS < 45), intermediate-term mortality, and anesthetic dose after cardiac surgery.

Methods: The authors studied 460 patients (mean age, 63.

Anesthesia awareness and the bispectral index.

Background: Awareness during anesthesia is a serious complication with potential long-term psychological consequences. Use of the bispectral index (BIS), developed from a processed electroencephalogram, has been reported to decrease the incidence of anesthesia awareness when the BIS value is maintained below 60. In this trial, we sought to determine whether a BIS-based protocol is better than a protocol based on a measurement of end-tidal anesthetic gas (ETAG) for decreasing anesthesia awareness in patients at high risk for this complication.