Bispectral Index Monitoring, Duration of Bispectral Index Below 45, Patient Risk Factors, and Intermediate-term Mortality after Noncardiac Surgery in the B-Unaware Trial

Abstract

Background: Postoperative mortality has been associated with cumulative anesthetic duration below an arbitrary processed electroencephalographic threshold (bispectral index [BIS] Ͻ45). 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 Ϯ SD age, 57.9 Ϯ 14.4 yr; 749 men) who underwent noncardiac surgery at Barnes-Jewish Hospital in St. Louis, Missouri. Multivariable Cox regression analysis was used to determine whether perioperative factors were independently associated with all-cause mortality. Results: A total of 358 patients (24.3%) died during a follow-up of 3.2 Ϯ 1.1 yr. There were statistically significant associations among various perioperative risk factors, including malignancy and intermediate-term mortality. BIS-monitored patients did not have lower mortality than unmonitored patients (24.9 vs. 23.7%; difference ϭ 1.2%, 95% CI, Ϫ3.3 to 5.6%). Cumulative duration of BIS values less than 45 was not associated with mortality (multivariable hazard

Disfunción cognitiva después de cirugía cardiaca: Saturación cerebral e índice biespectral: estudio longitudinal

“…Estudiamos esta asociación dado que el descenso brusco e inexplicable del BIS se ha relacionado con hipoperfusión cerebral [28][29][30][31][32][33][34] , sugiriéndose que este monitor ayudaría a detectar una hipoperfusión cerebral aguda en pacientes de alto riesgo 27,[31][32][33][34] . A pesar de estos reportes, no se ha observado asociación entre BIS y morbi-mortalidad postoperatoria 35,43,59,60 , por lo que no se ha recomendado su uso rutinario en una población no seleccionada de pacientes 27,[60][61][62] . La puntuación del RAVLT basal fue la única diferencia signifi cativa entre los grupos estudiados (Tabla 2).…”

Developmental Disability in the Young and Postoperative Cognitive Dysfunction in the Elderly After Anesthesia and Surgery: Do Data Justify Changing Clinical Practice?

“…122 Congruent with those findings, Kertai and coauthors concluded that results from the B-Unaware trial ''do not support the hypothesis that limiting depth of anesthesia either by titration to a specific BIS threshold or by limiting end-tidal volatile agent concentrations will decrease postoperative mortality.'' 123 If the association between POCD and mortality is valid and causal, 87 the Kertai conclusion 123 would also imply that maintaining a high BIS does not reduce POCD. In an editorial accompanying that article, Kalkman and Peelen reminded readers that ''.…”

Isoproterenol Increases BIS and Arousal during Catheter Ablation for Atrial Fibrillation

“…Patients were maintained on infusions of propofol ranging from 25 to 200 mcg/kg/min titrated to a BIS target of 50 ± 5 and an infusion of remifentanil ranging from 30 to 100 ng/kg/min with no further use of muscle relaxants. Controlled ventilation with an endotracheal tube (ET) was maintained with an ETCO 2 = 33 ± 3 and respiratory rate (RR) [8][9][10][11][12].…”