Awareness Under Anesthesia.

You begin to hear distant rock music playing, people conversing about their weekend. Then the scalpel is requested-incision. Pain sends you reeling and you attempt to muster a scream. No one seems to hear you and you are unable to lift a finger. The scenario is so rare that numerous movies have been made about awareness under anesthesia. Awareness under anesthesia is a rare event, however, it is a complication that no one ever desires to occur. We will explore how frequent awareness is during surgery, what risk factors are involved, and what tools anesthesia providers utilize to ensure everyone undergoing surgery is adequately anesthetized.

Frailty Phenotypes and Relations With Surgical Outcomes: A Latent Class Analysis.

BACKGROUND: Frailty is an important concept in the care of older adults although controversy remains regarding its defining features and clinical utility. Both the Fried phenotype and the Rockwood deficit accumulation approaches cast frailty as a "burden" without exploring the relative salience of its cardinal markers and their relevance to the patient. New multifactorial perspectives require a reliable assessment of frailty that can validly predict postoperative health outcomes. METHODS: In a retrospective study of 2828 unselected surgical patients, we used item response theory to examine the ability of 32 heterogeneous markers capturing limitations in physical, functional, emotional, and social activity domains to indicate severity of frailty as a latent continuum. Eighteen markers efficiently indicated frailty severity and were then subject to latent class analysis to derive discrete phenotypes. Next, we validated the obtained frailty phenotypes against patient-reported 30-day postoperative outcomes using multivariable logistic regression. Models were adjusted for demographics, comorbidity, type and duration of surgery, and cigarette and alcohol consumption. RESULTS: The 18 markers provided psychometric evidence of a single reliable continuum of frailty severity. Latent class analyses produced 3 distinct subtypes, based on patients' endorsement probabilities of the frailty indicators: not frail (49.7%), moderately frail (33.5%), and severely frail (16.7%). Unlike the moderate class, severely frail endorsed emotional health problems in addition to physical burdens and functional limitations. Models adjusting for age, sex, type of anesthesia, and intraoperative factors indicated that severely frail (odds ratio, 1.89; 95% confidence interval, 1.42-2.50) and moderately frail patients (odds ratio, 1.31; 95% confidence interval, 1.03-1.67) both had higher odds of experiencing postoperative complications compared to not frail patients. In a 3-way comparison, a higher proportion of severely frail patients (10.7%) reported poorer quality of life after surgery compared to moderately frail (9.2%) and not frail (8.3%) patients (P < .001). There was no significant difference among these groups in proportions reporting hospital readmission (5.6%, 5.1%, and 3.8%, respectively; P = .067). CONCLUSIONS: Self-report frailty items can accurately discern 3 distinct phenotypes differing in composition and their relations with surgical outcomes. Systematically assessing a wider set of domains including limitations in functional, emotional, and social activities can inform clinicians on what precipitates loss of physiological reserve and profoundly influences patients' lives. This information can help guide the current discussion on frailty and add meaningful clinical tools to the surgical practice.

Preoperative Falls and Their Association with Functional Dependence and Quality of Life.

BACKGROUND: No study has rigorously explored the characteristics of surgical patients with recent preoperative falls. Our objective was to describe the essential features of preoperative falls and determine whether they are associated with preoperative functional dependence and poor quality of life. METHODS: This was an observational study involving 15,060 surveys from adult patients undergoing elective surgery. The surveys were collected between January 2014 and August 2015, with a response rate of 92%. RESULTS: In the 6 months before surgery, 26% (99% CI, 25 to 27%) of patients fell at least once, and 12% (99% CI, 11 to 13%) fell at least twice. The proportion of patients who fell was highest among patients presenting for neurosurgery (41%; 99% CI, 36 to 45%). At least one fall-related injury occurred in 58% (99% CI, 56 to 60%) of those who fell. Falls were common in all age groups, but surprisingly, they did not increase monotonically with age. Middle-aged patients (45 to 64 yr) had the highest proportion of fallers (28%), recurrent fallers (13%), and severe fall-related injuries (27%) compared to younger (18 to 44 yr) and older (65+ yr) patients (P < 0.001 for each). A fall within 6 months was independently associated with preoperative functional dependence (odds ratio, 1.94; 99% CI, 1.68 to 2.24) and poor physical quality of life (odds ratio, 2.18; 99% CI, 1.88 to 2.52). CONCLUSIONS: Preoperative falls might be common and are possibly often injurious in the presurgical population, across all ages. A history of falls could enhance the assessment of preoperative functional dependence and quality of life.

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, 57.9 ± 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 ± 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 = 1.2%, 95% CI, -3.3 to 5.6%). Cumulative duration of BIS values less than 45 was not associated with mortality (multivariable hazard ratio, 1.03; 95% CI, 0.93-1.14). Increasing mean and cumulative end-tidal anesthetic concentrations were not associated with mortality. The multivariable Cox regression model showed a good discriminative ability (c-index = 0.795). CONCLUSIONS: This study found no evidence that either cumulative BIS values below a threshold of 40 or 45 or cumulative inhalational anesthetic dose is injurious to patients. These results 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.