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During the past 70 years, patient safety science has evolved through four organizational frameworks known as Safety-0, Safety -1, Safety-2, and Safety-3. Their evolution reflects the realization over time that blaming people, chasing errors, fixing one-offs, and regulation would not create the desired patient safety. In Safety-0, the oldest framework, harm events arise from clinician failure; event prevention relies on better staffing, education, and basic standards. In Safety-1, used by hospitals, harm events arise from individual and/or system failures. Safety is improved through analytics, workplace culture, high reliability principles, technology, and quality improvement. Safety-2 emphasizes clinicians' adaptability to prevent harm events in an everchanging environment, using resilience engineering principles. Safety-3, used by aviation, adds system design and control elements to Safety-1 and Safety-2, deploying human factors, design-thinking, and operational control or feedback to prevent and respond to harm events. Safety-3 represents a potential way for anesthesia and perioperative care to become safer., (Copyright © 2024 American Society of Anesthesiologists. All Rights Reserved.)

Ellison C. Pierce, Jr., M.D., and a small number of specialty leaders and scientists formed a remarkable, diverse team in the mid-1980s to address a dual crisis: a safety crisis for anesthetized patients and a medical malpractice insurance crisis for anesthesiologists. This cohesive team's efforts led to the formation of the Anesthesia Patient Safety Foundation, the American Society of Anesthesiologists's Committees on Standards of Care and on Patient Safety and Risk Management, and the society's Closed Claims Project. The commonality of leaders and members of the Anesthesia Patient Safety Foundation and American Society of Anesthesiologists initiatives provided the strong coordination needed for their efforts to effect change, introduce standards of care and practice parameters, obtain financial support needed to grow patient safety-oriented new knowledge, integrate industry and other relevant leaders outside of anesthesiology, and involve all anesthesia professions. By implementing successful patient safety initiatives, they promoted the recognition that anesthesiology and patient safety are inextricably linked., (Copyright © 2021, the American Society of Anesthesiologists. All Rights Reserved.)

What We Already Know About This Topic: Debriefing after an actual critical event is an established good practice in medicine, but a gap exists between principle and implementation., What This Article Tells Us That Is New: Failure to debrief after critical events is common among anesthesia trainees and likely anesthesia teams. Communication breakdowns are associated with a high rate of the failure to debrief., Background: Debriefing after an actual critical event is an established good practice in medicine, but a gap exists between principle and implementation. The authors' objective was to understand barriers to debriefing, characterize quantifiable patterns and qualitative themes, and learn potential solutions through a mixed-methods study of actual critical events experienced by anesthesia personnel., Methods: At a large academic medical center, anesthesiology residents and a small number of attending anesthesiologists were audited and/or interviewed for the occurrence and patterns of debriefing after critical events during their recent shift, including operating room crises and disruptive behavior. Patterns of the events, including event locations and event types, were quantified. A comparison was done of the proportion of cases debriefed based on whether the event contained a critical communication breakdown. Qualitative analysis, using an abductive approach, was performed on the interviews to add insight to quantitative findings., Results: During a 1-yr period, 89 critical events were identified. The overall debriefing rate was 49% (44 of 89). Nearly half of events occurred outside the operating room. Events included crisis events (e.g., cardiac arrest, difficult airway requiring an urgent surgical airway), disruptive behavior, and critical communication breakdowns. Events containing critical communication breakdowns were strongly associated with not being debriefed (64.4% [29 of 45] not debriefed in events with a communication breakdown vs. 36.4% [16 of 44] not debriefed in cases without a communication breakdown; P = 0.008). Interview responses qualitatively demonstrated that lapses in communication were associated with enduring confusion that could inhibit or shape the content of discussions between involved providers., Conclusions: Despite the value of proximal debriefing to reducing provider burnout and improving wellness and learning, failure to debrief after critical events can be common among anesthesia trainees and perhaps anesthesia teams. Modifiable interpersonal factors, such as communication breakdowns, were associated with the failure to debrief.

Quality has been defined by six domains: effective, equitable, timely, efficient, safe, and patient centered. Quality of anesthesia care can be improved through measurement, either through local measures in quality improvement or through national measures in value-based purchasing programs. Death directly related to anesthesia care has been reduced, but must be measured beyond simple mortality. To improve perioperative care for our patients, we must take shared accountability for all surgical outcomes including complications, which has traditionally been viewed as being surgically related. Anesthesiologists can also impact public health by being engaged in improving cognitive recovery after surgery and addressing the opiate crisis. Going forward, we must focus on what patients want and deserve: improved patient-oriented outcomes and satisfaction with our care. By listening to our patients and being engaged in the entire perioperative process, we can make the greatest impact on perioperative care.

Background: Vital parameter data collected in anesthesia information management systems are often used for clinical research. The validity of this type of research is dependent on the number of artifacts., Methods: In this prospective observational cohort study, the incidence of artifacts in anesthesia information management system data was investigated in children undergoing anesthesia for noncardiac procedures. Secondary outcomes included the incidence of artifacts among deviating and nondeviating values, among the anesthesia phases, and among different anesthetic techniques., Results: We included 136 anesthetics representing 10,236 min of anesthesia time. The incidence of artifacts was 0.5% for heart rate (95% CI: 0.4 to 0.7%), 1.3% for oxygen saturation (1.1 to 1.5%), 7.5% for end-tidal carbon dioxide (6.9 to 8.0%), 5.0% for noninvasive blood pressure (4.0 to 6.0%), and 7.3% for invasive blood pressure (5.9 to 8.8%). The incidence of artifacts among deviating values was 3.1% for heart rate (2.1 to 4.4%), 10.8% for oxygen saturation (7.6 to 14.8%), 14.1% for end-tidal carbon dioxide (13.0 to 15.2%), 14.4% for noninvasive blood pressure (10.3 to 19.4%), and 38.4% for invasive blood pressure (30.3 to 47.1%)., Conclusions: Not all values in anesthesia information management systems are valid. The incidence of artifacts stored in the present pediatric anesthesia practice was low for heart rate and oxygen saturation, whereas noninvasive and invasive blood pressure and end-tidal carbon dioxide had higher artifact incidences. Deviating values are more often artifacts than values in a normal range, and artifacts are associated with the phase of anesthesia and anesthetic technique. Development of (automatic) data validation systems or solutions to deal with artifacts in data is warranted.

Background: When workload is low, anesthesia providers may perform non-patient care activities of a clinical, educational, or personal nature. Data are limited on the incidence or impact of distractions on actual care. We examined the prevalence of self-initiated nonclinical distractions and their effects on anesthesia workload, vigilance, and the occurrence of nonroutine events., Methods: In 319 qualifying cases in an academic medical center using a Web-based electronic medical chart, a trained observer recorded video and performed behavioral task analysis. Participant workload and response to a vigilance (alarm) light were randomly measured. Postoperatively, participants were interviewed to elicit possible nonroutine events. Two anesthesiologists reviewed each event to evaluate their association with distractions., Results: At least one self-initiated distraction was observed in 171 cases (54%), largely during maintenance. Distractions accounted for 2% of case time and lasted 2.3 s (median). The most common distraction was personal internet use. Distractions were more common in longer cases but were not affected by case type or American Society of Anesthesiologists physical status. Workload ratings were significantly lower during distraction-containing case periods and vigilance latencies were significantly longer in cases without any distractions. Three distractions were temporally associated with, but did not cause, events., Conclusions: Both nurse anesthetists and residents performed potentially distracting tasks of a personal and/or educational nature in a majority of cases. Self-initiated distractions were rarely associated with events. This study suggests that anesthesia professionals using sound judgment can self-manage nonclinical activities. Future efforts should focus on eliminating more cognitively absorbing and less escapable distractions, as well as training in distraction management.

Background: Simulation has been used to investigate clinical questions in anesthesia, surgery, and related disciplines, but there are few data demonstrating that results apply to clinical settings. We asked "would results of a simulation-based study justify the same principal conclusions as those of a larger clinical study?", Methods: We compared results from a randomized controlled trial in a simulated environment involving 80 cases at three centers with those from a randomized controlled trial in a clinical environment involving 1,075 cases. In both studies, we compared conventional methods of anesthetic management with the use of a multimodal system (SAFERsleep; Safer Sleep LLC, Nashville, Tennessee) designed to reduce drug administration errors. Forty anesthesiologists each managed two simulated scenarios randomized to conventional methods or the new system. We compared the rate of error in drug administration or recording for the new system versus conventional methods in this simulated randomized controlled trial with that in the clinical randomized controlled trial (primary endpoint). Six experts were asked to indicate a clinically relevant effect size., Results: In this simulated randomized controlled trial, mean (95% CI) rates of error per 100 administrations for the new system versus conventional groups were 6.0 (3.8 to 8.3) versus 11.6 (9.3 to 13.8; P = 0.001) compared with 9.1 (6.9 to 11.4) versus 11.6 (9.3 to 13.9) in the clinical randomized controlled trial (P = 0.045). A 10 to 30% change was considered clinically relevant. The mean (95% CI) difference in effect size was 27.0% (-7.6 to 61.6%)., Conclusions: The results of our simulated randomized controlled trial justified the same primary conclusion as those of our larger clinical randomized controlled trial, but not a finding of equivalence in effect size.

Background: Several quality of recovery (QoR) health status scales have been developed to quantify the patient's experience after anesthesia and surgery, but to date, it is unclear what constitutes the minimal clinically important difference (MCID). That is, what minimal change in score would indicate a meaningful change in a patient's health status?, Methods: The authors enrolled a sequential, unselected cohort of patients recovering from surgery and used three QoR scales (the 9-item QoR score, the 15-item QoR-15, and the 40-item QoR-40) to quantify a patient's recovery after surgery and anesthesia. The authors compared changes in patient QoR scores with a global rating of change questionnaire using an anchor-based method and three distribution-based methods (0.3 SD, standard error of the measurement, and 5% range). The authors then averaged the change estimates to determine the MCID for each QoR scale., Results: The authors enrolled 204 patients at the first postoperative visit, and 199 were available for a second interview; a further 24 patients were available at the third interview. The QoR scores improved significantly between the first two interviews. Triangulation of distribution- and anchor-based methods results in an MCID of 0.92, 8.0, and 6.3 for the QoR score, QoR-15, and QoR-40, respectively., Conclusion: Perioperative interventions that result in a change of 0.9 for the QoR score, 8.0 for the QoR-15, or 6.3 for the QoR-40 signify a clinically important improvement or deterioration.

Background: Misidentification of the cricothyroid membrane in a "cannot intubate-cannot oxygenate" situation can lead to failures and serious complications. The authors hypothesized that preprocedure ultrasound-guided identification of the cricothyroid membrane would reduce complications associated with cricothyrotomy., Methods: A group of 47 trainees were randomized to digital palpation (n = 23) and ultrasound (n = 24) groups. Cricothyrotomy was performed on human cadavers by using the Portex device (Smiths Medical, USA). Anatomical landmarks of cadavers were graded as follows: grade 1-easy = visual landmarks; 2-moderate = requires light palpation of landmarks; 3-difficult = requires deep palpation of landmarks; and 4-impossible = landmarks not palpable. Primary outcome was the complication rate as measured by the severity of injuries. Secondary outcomes were correct device placement, failure to cannulate, and insertion time., Results: Ultrasound guidance significantly decreased the incidence of injuries to the larynx and trachea (digital palpation: 17 of 23 = 74% vs. ultrasound: 6 of 24 = 25%; relative risk, 2.88; 95% CI, 1.39 to 5.94; P = 0.001) and increased the probability of correct insertion by 5.6 times (P = 0.043) in cadavers with difficult and impossible landmark palpation (digital palpation 8.3% vs. ultrasound 46.7%). Injuries were found in 100% of the grades 3 to 4 (difficult-impossible landmark palpation) cadavers by digital palpation compared with only 33% by ultrasound (P < 0.001). The mean (SD) insertion time was significantly longer with ultrasound than with digital palpation (196.1 s [60.6 s] vs. 110.5 s [46.9 s]; P < 0.001)., Conclusion: Preprocedure ultrasound guidance in cadavers with poorly defined neck anatomy significantly reduces complications and improves correct insertion of the airway device in the cricothyroid membrane.

Background: Transfers of patient care and responsibility among caregivers, "handovers," are common. Whether handovers worsen patient outcome remains unclear. The authors tested the hypothesis that intraoperative care transitions among anesthesia providers are associated with postoperative complications., Methods: From the records of 138,932 adult Cleveland Clinic (Cleveland, Ohio) surgical patients, the authors assessed the association between total number of anesthesia handovers during a case and an adjusted collapsed composite of in-hospital mortality and major morbidities using multivariable logistic regression., Results: Anesthesia care transitions were significantly associated with higher odds of experiencing any major in-hospital mortality/morbidity (incidence of 8.8, 11.6, 14.2, 17.0, and 21.2% for patients with 0, 1, 2, 3, and ≥ 4 transitions; odds ratio 1.08 [95% CI, 1.05 to 1.10] for an increase of 1 transition category, P < 0.001). Care transitions among attending anesthesiologists and residents or nurse anesthetists were similarly associated with harm (odds ratio 1.07 [98.3% CI, 1.03 to 1.12] for attending [incidence of 9.4, 13.9, 17.4, and 21.5% for patients with 0, 1, 2, and ≥ 3 transitions] and 1.07 [1.04 to 1.11] for residents or nurses [incidence of 9.4, 13.0, 15.4, and 21.2% for patients with 0, 1, 2, and ≥ 3 transitions], both P < 0.001). There was no difference between matched resident only (8.5%) and nurse anesthetist only (8.8%) cases on the collapsed composite outcome (odds ratio, 1.00 [98.3%, 0.93 to 1.07]; P = 0.92)., Conclusion: Intraoperative anesthesia care transitions are strongly associated with worse outcomes, with a similar effect size for attendings, residents, and nurse anesthetists.

Background: Valid methods are needed to identify anesthesia resident performance gaps early in training. However, many assessment tools in medicine have not been properly validated. The authors designed and tested use of a behaviorally anchored scale, as part of a multiscenario simulation-based assessment system, to identify high- and low-performing residents with regard to domains of greatest concern to expert anesthesiology faculty., Methods: An expert faculty panel derived five key behavioral domains of interest by using a Delphi process (1) Synthesizes information to formulate a clear anesthetic plan; (2) Implements a plan based on changing conditions; (3) Demonstrates effective interpersonal and communication skills with patients and staff; (4) Identifies ways to improve performance; and (5) Recognizes own limits. Seven simulation scenarios spanning pre-to-postoperative encounters were used to assess performances of 22 first-year residents and 8 fellows from two institutions. Two of 10 trained faculty raters blinded to trainee program and training level scored each performance independently by using a behaviorally anchored rating scale. Residents, fellows, facilitators, and raters completed surveys., Results: Evidence supporting the reliability and validity of the assessment scores was procured, including a high generalizability coefficient (ρ = 0.81) and expected performance differences between first-year resident and fellow participants. A majority of trainees, facilitators, and raters judged the assessment to be useful, realistic, and representative of critical skills required for safe practice., Conclusion: The study provides initial evidence to support the validity of a simulation-based performance assessment system for identifying critical gaps in safe anesthesia resident performance early in training.

Background: The literature is mixed on whether evaluation and feedback to clinical teachers improves clinical teaching. This study sought to determine whether resident-provided numerical evaluation and written feedback to clinical teachers improved clinical teaching scores., Methods: Anesthesia residents anonymously provided numerical scores and narrative comments to faculty members who provided clinical teaching. Residents returned 19,306 evaluations between December 2000 and May 2006. Faculty members received a quantitative summary report and all narrative comments every 6 months. Residents also filled out annual residency program evaluations in which they listed the best and worst teachers in the department., Results: The average teaching score for the entire faculty rose over time and reached a plateau with a time constant of approximately 1 yr. At first, individual faculty members had average teaching scores that were numerically diverse. Over time, the average scores became more homogeneous. Faculty members ranked highest by teaching scores were also most frequently named as the best teachers. Faculty members ranked lowest by teaching scores were most frequently named as the worst teachers. Analysis of ranks, differential improvement in scores, and a decrease in score diversity effectively ruled out simple score inflation as the cause for increased scores. An increase in teaching scores was most likely due to improved teaching., Conclusions: A combination of evaluation and feedback, including comments on areas for improvement, was related to a substantial improvement in teaching scores. Clinical teachers are able to improve by using feedback from residents.

Background: The noxious stimulation response index (NSRI) is a novel anesthetic depth index ranging between 100 and 0, computed from hypnotic and opioid effect-site concentrations using a hierarchical interaction model. The authors validated the NSRI on previously published data., Methods: The data encompassed 44 women, American Society of Anesthesiology class I, randomly allocated to three groups receiving remifentanil infusions targeting 0, 2, and 4 ng/ml. Propofol was given at stepwise increasing effect-site target concentrations. At each concentration, the observer assessment of alertness and sedation score, the response to eyelash and tetanic stimulation of the forearm, the bispectral index (BIS), and the acoustic evoked potential index (AAI) were recorded. The authors computed the NSRI for each stimulation and calculated the prediction probabilities (PKs) using a bootstrap technique. The PKs of the different predictors were compared with multiple pairwise comparisons with Bonferroni correction., Results: The median (95% CI) PK of the NSRI, BIS, and AAI for loss of response to tetanic stimulation was 0.87 (0.75-0.96), 0.73 (0.58-0.85), and 0.70 (0.54-0.84), respectively. The PK of effect-site propofol concentration, BIS, and AAI for observer assessment of alertness and sedation score and loss of eyelash reflex were between 0.86 (0.80-0.92) and 0.92 (0.83-0.99), whereas the PKs of NSRI were 0.77 (0.68-0.85) and 0.82 (0.68-0.92). The PK of the NSRI for BIS and AAI was 0.66 (0.58-0.73) and 0.63 (0.55-0.70), respectively., Conclusion: The NSRI conveys information that better predicts the analgesic component of anesthesia than AAI, BIS, or predicted propofol or remifentanil concentrations. Prospective validation studies in the clinical setting are needed.

Clinical indicators are increasingly developed and promoted by professional organizations, governmental agencies, and quality initiatives as measures of quality and performance. To clarify the number, characteristics, and validity of indicators available for anesthesia care, the authors performed a systematic review. They identified 108 anesthetic clinical indicators, of which 53 related also to surgical or postoperative ward care. Most were process (42%) or outcome (57%) measures assessing the safety and effectiveness of patient care. To identify possible quality issues, most clinical indicators were used as part of interhospital comparison or professional peer-review processes. For 60% of the clinical indicators identified, validity relied on expert opinion. The level of scientific evidence on which prescriptive indicators ("how things should be done") were based was high (1a-1b) for 38% and low (4-5) for 62% of indicators. Additional efforts should be placed into the development and validation of anesthesia-specific quality indicators.

Background: Patient satisfaction has become an important component of quality improvement in ambulatory anesthesia services. However, it is difficult to measure due to its subjective and complex psychological construct. Psychometric methodology has been successfully used to evaluate this outcome. The authors conducted a systematic review to evaluate questionnaires to measure patient satisfaction with ambulatory anesthesia., Methods: A systematic literature search of The Cochrane Library, MEDLINE, EMBASE, CINAHL, HAPI, PsycINFO, and Dissertation Abstracts was performed to identify studies on questionnaires evaluating patient satisfaction after ambulatory anesthesia. The authors included the articles that used multiple-item questionnaires, and the questionnaires were assessed with the strategy of psychometric questionnaire construction, validity, reliability, and acceptability., Results: The authors scanned 131 articles yielded by our search strategy. Eleven articles were included in the study. Two questionnaires, IOWA Satisfaction with Anesthesia Scale and Evaluation du Vecu de I'Anesthesie Generale, fulfilled the criteria, but the latter was not developed specifically for ambulatory anesthesia, whereas Iowa Satisfaction with Anesthesia Scale was designed only for monitored anesthesia patients., Conclusions: In a large number of trials, patient satisfaction has been evaluated using overall satisfaction or nonvalidated questionnaires. Only a few studies have developed questionnaires with rigorous psychometric methods to measure patient satisfaction with anesthesia care. At this time, there is still no valid or reliable questionnaire for measuring patient satisfaction in ambulatory anesthesia. Further study should be conducted to develop standardized instruments to measure this outcome.

Background: It is increasingly important to evaluate patients' recovery after ambulatory surgery. The authors developed the Functional Recovery Index (FRI) to assess postdischarge functional recovery for ambulatory surgical patients., Methods: The scale development involved four phases: item generation, item selection, reliability, and validity testing. A draft questionnaire was tested and revised. Items were selected through testing endorsement frequency, factor analysis, and testing internal consistency. The interrater reliability was calculated. Construct validity was tested by multiple hypotheses on convergent validity, extreme groups, and discriminant validity. Responsiveness was assessed by measuring the FRI postoperatively and comparing minor versus more extensive surgery. The rate of response and the time for completion of the questionnaire were recorded., Results: The final questionnaire had 14 items grouped under 3 factors. Each item was scored from 0 to 10, with 0 = no difficulty and 10 = extreme difficulty with the activity. The 3 factors were summated for a total score. Internal consistency for the 3 factors (pain and social activity, lower limb activity, and general physical activity) was as follows: Cronbach alpha = 0.90, 0.89, and 0.86, respectively. Interrater reliability was 0.99. Convergent validity for FRI versus verbal rating scale pain score was 0.76. Discriminant validity testing showed that the type of surgery was significant and that intermediate (beta = 0.138) and major surgery (beta = 0.337) were associated with higher FRI scores than minor surgery. The time to complete the questionnaires ranged between 4 min 10 s and 4 min 35 s., Conclusions: The FRI had excellent reliability, good validity, responsiveness, and acceptability, indicating that this questionnaire will be a good instrument for assessing functional recovery of ambulatory surgical patients.

Background: Nonlinear electroencephalographic parameters, e.g., approximate entropy, have been suggested as measures of the hypnotic component of anesthesia. Compared with linear methods, they may detect additional information and quantify the irregularity of a dynamical system. High dimensionality of a signal and disturbances may affect these parameters and change their ability to distinguish consciousness from unconsciousness. Methods of order pattern analysis, in this investigation represented by permutation entropy, recurrence rate, and phase coupling of order recurrence plots, are suitable for any type of time series, whether deterministic or noisy. They may provide a better estimation of the hypnotic component of anesthesia than other nonlinear parameters., Methods: The current analysis is based on electroencephalographic data from two similar clinical studies in adult patients undergoing general anesthesia with sevoflurane or propofol. The study period was from induction until patients followed command after surgery, including a reduction of the hypnotic agent after tracheal intubation until patients followed command. Prediction probability was calculated to assess the parameter's ability to separate consciousness from unconsciousness at the transition between both states., Results: Parameters of order pattern analysis provide a prediction probability of maximal 0.85 (training study) and 0.78 (evaluation study) with frequencies from 0 to 30 Hz, and maximal 0.87 (training study) and 0.83 (evaluation study) including frequencies up to 70 Hz, both higher than 0.77 (approximate entropy)., Conclusions: Parameters of the nonlinear method order pattern analysis separate consciousness from unconsciousness and are grossly independent of high-frequency components of the electroencephalogram.

Background: Anesthesia information management systems allow automatic recording of physiologic and anesthetic data. The authors investigated the prevalence of such data modification in an academic medical center., Methods: The authors queried their anesthesia information management system database of anesthetics performed in 2006 and tabulated the counts of data points for automatically recorded physiologic and anesthetic parameters as well as the subset of those data that were manually invalidated by clinicians (both with and without alternate values manually appended). Patient, practitioner, data source, and timing characteristics of recorded values were also extracted to determine their associations with editing of various parameters in the anesthesia information management system record., Results: A total of 29,491 cases were analyzed, 19% of which had one or more data points manually invalidated. Among 58 attending anesthesiologists, each invalidated data in a median of 7% of their cases when working as a sole practitioner. A minority of invalidated values were manually appended with alternate values. Pulse rate, blood pressure, and pulse oximetry were the most commonly invalidated parameters. Data invalidation usually resulted in a decrease in parameter variance. Factors independently associated with invalidation included extreme physiologic values, American Society of Anesthesiologists physical status classification, emergency status, timing (phase of the procedure/anesthetic), presence of an intraarterial catheter, resident or certified registered nurse anesthetist involvement, and procedure duration., Conclusions: Editing of physiologic data automatically recorded in an anesthesia information management system is a common practice and results in decreased variability of intraoperative data. Further investigation may clarify the reasons for and consequences of this behavior.

Background: Sleep deprivation causes physiologic and subjective sleepiness. Studies of fatigue effects on anesthesiologist performance have given equivocal results. The authors used a realistic simulation environment to study the effects of sleep deprivation on psychomotor and clinical performance, subjective and objective sleepiness, and mood., Methods: Twelve anesthesia residents performed a 4-h anesthetic on a simulated patient the morning after two conditions of prior sleep: sleep-extended (EXT), in which subjects were allowed to arrive at work at 10:00 AM for 4 consecutive days, thus allowing an increase in nocturnal sleep time, and total sleep deprivation (DEP), in which subjects were awake at least 25 h. Psychomotor testing was performed at specified periods throughout the night in the DEP condition and at matched times during the simulation session in both conditions. Three types of vigilance probes were presented to subjects at random intervals as well as two clinical events. Task analysis and scoring of alertness were performed retrospectively from videotape., Results: In the EXT condition, subjects increased their sleep by more than 2 h from baseline (P = 0.0001). Psychomotor tests revealed progressive impairment of alertness, mood, and performance in the DEP condition over the course of the night and when compared with EXT during the experimental day. DEP subjects showed longer response latency to vigilance probes, although this was statistically significant for only one probe type. Task analysis showed no difference between conditions except that subjects "slept" more in the DEP condition. There was no significant difference in the cases' clinical management between sleep conditions. Subjects in the DEP condition had lower alertness scores (P = 0.02), and subjects in the EXT condition showed little video evidence of sleepiness., Conclusions: Psychomotor performance and mood were impaired while subjective sleepiness and sleepy behaviors increased during simulated patient care in the DEP condition. Clinical performance between conditions was similar.

The authors examined the American Society of Anesthesiologists Closed Claims Study database to define the role of nerve damage in the overall spectrum of anesthesia-related injury that leads to litigation. Of 1,541 claims reviewed, 227 (15%) were for anesthesia-related nerve injury. Ulnar neuropathy represented one-third of all nerve injuries and was the most frequent nerve injury. Less-frequent sites of nerve injury were the brachial plexus (23%) and the lumbosacral nerve roots (16%). In a large proportion of cases, the exact mechanism of injury was unclear despite evidence of intensive investigation in the claim files. Median payment for nerve damage claims involving disabling injury was $56,000, which was significantly lower than the $225,000 median payment for claims for disabling injury not involving nerve damage (P less than 0.01). The closed claims reviewers judged that the standard of care had been met significantly more often in claims involving nerve damage than in claims not involving nerve damage. The authors conclude that nerve damage is a significant source of anesthesia-related claims but that the exact mechanism of nerve injury is often unclear. In particular, ulnar nerve injuries seemed to occur without identifiable mechanism.

Among 1,001,000 ASA Physical Status I and II patients (a subset of the 1,329,000 anesthetics administered from 1976 through mid-1988 in the nine component hospitals of the Harvard Department of Anaesthesia), there were 11 major intraoperative accidents solely attributable to anesthesia (five deaths, four cases of permanent CNS damage, and two cardiac arrests with eventual recovery) among the 70 cases reported to the insurance carrier. Review of these accidents revealed that unrecognized hypoventilation was the most common cause (seven cases). These seven accidents and one other due to discontinuation of inspired oxygen in all likelihood would have been prevented by appropriate response to earlier warnings generated by the "safety monitoring" principles mandated by the Harvard minimal monitoring standards. Analysis suggests capnography (although not mandated) would be the best monitor of ventilation. An important associated issue was the apparent inadequacy of supervision of residents and C.R.N.A.s. The eight preventable accidents represent 88% of the projected insurance payout. Only one accident occurred after the 1985 adoption of the standards (in the month following their implementation). From that time through mid-1988, there have been 319,000 anesthetics without a major preventable intraoperative injury. Although not statistically significant, the accident rate in the target population of healthy people is reduced more than threefold. This and the case analyses support the contention that nearly all the inevitable mishaps (technical or from errors in judgement) that occur during anesthesia can be identified through safety monitoring early enough to prevent most major patient injuries. This improved clinical outcome should lessen the medical-legal and malpractice insurance burdens of anesthesiologists.

Anesthesia and surgery are a risk for all, the healthy as well as the sick. While the prevention of adverse outcomes in healthy patients is paramount, enhancement of safety for critically ill patients is also essential, since they are more likely to suffer a SNO after a critical incident. Dangers originate from a variety of sources, not solely from errors by the anesthesiologist. Simple incidents of all description are inevitable, and we should focus on promoting recovery as well as avoiding error. Processes that lead to negative outcomes after critical incidents should be investigated to reduce the uncertainty complexity associated with managing the human body during anesthesia, and to establish the most effective detection and recovery techniques. Outcome studies are lacking, and clinical and animal research is highly dependent on the chosen model or population, making the results hard to apply to variable clinical conditions. Wherever possible, a consensus should be sought on therapeutic and adverse effects of drugs and techniques in common, specific patient populations. These can serve as a basis for developing therapeutic plans, recognizing that customizing to individuals is always necessary. A mainstay of anesthetic practice already involves attempts to loosen couplings, by keeping homeostatic mechanisms intact when possible (awake intubation, regional anesthesia); providing temporal buffers (titration of drugs, and use of drugs with short onset times and rapid termination of effect); and providing safety margins using appropriate pre-treatments (pre-oxygenation, atropine in children, etc.). Further means of loosening coupling should be identified and promoted. Specific attention to recovery from simple incidents should attack several facets of the problem.(ABSTRACT TRUNCATED AT 250 WORDS)