Effect of Electroencephalography-Guided Anesthetic Administration on Postoperative Delirium Among Older Adults Undergoing Major Surgery: The ENGAGES Randomized Clinical Trial

IMPORTANCE

Intraoperative electroencephalogram (EEG) waveform suppression, often suggesting excessive general anesthesia, has been associated with postoperative delirium.

OBJECTIVE

To assess whether EEG-guided anesthetic administration decreases the incidence of postoperative delirium.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial of 1232 adults aged 60 years and older undergoing major surgery and receiving general anesthesia at Barnes-Jewish Hospital in St Louis. Recruitment was from January 2015 to May 2018, with follow-up until July 2018.

INTERVENTIONS

Patients were randomized 1:1 (stratified by cardiac vs noncardiac surgery and positive vs negative recent fall history) to receive EEG-guided anesthetic administration (n = 614) or usual anesthetic care (n = 618).

MAIN OUTCOMES AND MEASURES

The primary outcome was incident delirium during postoperative days 1 through 5. Intraoperative measures included anesthetic concentration, EEG suppression, and hypotension. Adverse events included undesirable intraoperative movement, intraoperative awareness with recall, postoperative nausea and vomiting, medical complications, and death.

RESULTS

Of the 1232 randomized patients (median age, 69 years [range, 60 to 95]; 563 women [45.7%]), 1213 (98.5%) were assessed for the primary outcome. Delirium during postoperative days 1 to 5 occurred in 157 of 604 patients (26.0%) in the guided group and 140 of 609 patients (23.0%) in the usual care group (difference, 3.0% [95% CI, -2.0% to 8.0%]; P = .22). Median end-tidal volatile anesthetic concentration was significantly lower in the guided group than the usual care group (0.69 vs 0.80 minimum alveolar concentration; difference, -0.11 [95% CI, -0.13 to -0.10), and median cumulative time with EEG suppression was significantly less (7 vs 13 minutes; difference, -6.0 [95% CI, -9.9 to -2.1]). There was no significant difference between groups in the median cumulative time with mean arterial pressure below 60 mm Hg (7 vs 7 minutes; difference, 0.0 [95% CI, -1.7 to 1.7]). Undesirable movement occurred in 137 patients (22.3%) in the guided and 95 (15.4%) in the usual care group. No patients reported intraoperative awareness. Postoperative nausea and vomiting was reported in 48 patients (7.8%) in the guided and 55 patients (8.9%) in the usual care group. Serious adverse events were reported in 124 patients (20.2%) in the guided and 130 (21.0%) in the usual care group. Within 30 days of surgery, 4 patients (0.65%) in the guided group and 19 (3.07%) in the usual care group died.

CONCLUSIONS AND RELEVANCE

Among older adults undergoing major surgery, EEG-guided anesthetic administration, compared with usual care, did not decrease the incidence of postoperative delirium. This finding does not support the use of EEG-guided anesthetic administration for this indication.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02241655.

Independent discussion sections for improving inferential reproducibility in published research

There is a reproducibility crisis in science. There are many potential contributors to replication failure in research across the translational continuum. In this perspective piece, we focus on the narrow topic of inferential reproducibility. Although replication of methods and results is necessary to demonstrate reproducibility, it is not sufficient. Also fundamental is consistent interpretation in the Discussion section. Current deficiencies in the Discussion sections of manuscripts might limit the inferential reproducibility of scientific research. Lack of contextualisation using systematic reviews, overinterpretation and misinterpretation of results, and insufficient acknowledgement of limitations are common problems in Discussion sections; these deficiencies can harm the translational process. Proposed solutions include eliminating or not reading Discussions, writing accompanying editorials, and post-publication review and comments; however, none of these solutions works very well. A second Discussion written by an independent author with appropriate expertise in research methodology is a new testable solution that could help probe inferential reproducibility, and address some deficiencies in primary Discussion sections.

Early Postoperative Actigraphy Poorly Predicts Hypoactive Delirium

STUDY OBJECTIVES

Delirium is a postoperative complication accompanied by disturbances in attention, cognition, arousal, and psychomotor activity. Wrist actigraphy has been advocated to study inactivity and inferred sleep patterns during delirium. We hypothesized that altered patterns of motor activity or immobility, reflective of disordered sleep and wakefulness patterns, would serve as predictive markers of hypoactive postoperative delirium.

METHODS

Eighty-four elderly surgical patients were classified into three groups based on the timing of hypoactive delirium following surgery: intact with no delirium throughout postoperative days (POD) 0-5 (n = 51), delirium during POD 0-1 (n = 24), and delirium during POD 2-5 (n = 13). Delirium was detected on daily Confusion Assessment Method evaluations and chart review. Actigraphy measures were calculated from accelerometry signals acquired on the first postoperative day (POD 0, 16:00-23:00) and night (POD 0, 23:00-POD 1, 06:00).

RESULTS

Actigraphy metrics showed substantial interpatient variability. Among the three patient groups, only those without delirium showed greater movement during the day compared to night and also fewer minutes of night immobility (P = .03 and P = .02, Wilcoxon rank-sum tests). These patients were poorly discriminated from those with delirium during either POD 0-1 or POD 2-5, using differences in day and night activity (C-statistic, 95% confidence interval [CI]: 0.66 [0.53-0.79] and C-statistic, 95% CI: 0.71 [0.55-0.87], respectively). Inclusion of low-frequency signals improved performance of immobility measures without affecting those based on activity. Cognitively intact patients during POD 0-5 were distinguished from those with delirium during POD 0-1, based on differences in the number of day and night immobile minutes (C-statistic 0.65, 95% CI: [0.53-0.78]). Actigraphy metrics with the strongest association to delirium incidence were not reliably correlated with an increased risk during POD 0-5, when accounting for patient age, sex, intensive care unit admission, and Charlson Comorbidity Index (adjusted odds ratio of 1.7, 95% CI: [1.0-3.0], P = .09, likelihood ratio test).

CONCLUSIONS

Early postoperative wrist actigraphy metrics that serve as markers of sleep and wakefulness offer limited capacity as sole predictors or markers of hypoactive delirium.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Electroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes (ENGAGES) Study; Identifier: NCT02241655; URL: https://clinicaltrials.gov/ct2/show/NCT02241655.

Human neural correlates of sevoflurane-induced unconsciousness

Sevoflurane, a volatile anaesthetic agent well-tolerated for inhalation induction, provides a useful opportunity to elucidate the processes whereby halogenated ethers disrupt consciousness and cognition. Multiple molecular targets of sevoflurane have been identified, complementing imaging and electrophysiologic markers for the mechanistically obscure progression from wakefulness to unconsciousness. Recent investigations have more precisely detailed scalp EEG activity during this transition, with practical clinical implications. The relative timing of scalp potentials in frontal and parietal EEG signals suggests that sevoflurane might perturb the propagation of neural information between underlying cortical regions. Spatially distributed brain activity during general anaesthesia has been further investigated with positron emission tomography (PET) and resting-state functional magnetic resonance imaging (fMRI). Combined EEG and PET investigations have identified changes in cerebral blood flow and metabolic activity in frontal, parietal, and thalamic regions during sevoflurane-induced loss of consciousness. More recent fMRI investigations have revealed that sevoflurane weakens the signal correlations among brain regions that share functionality and specialization during wakefulness. In particular, two such resting-state networks have shown progressive breakdown in intracortical and thalamocortical connectivity with increasing anaesthetic concentrations: the Default Mode Network (introspection and episodic memory) and the Ventral Attention Network (orienting of attention to salient feature of the external world). These data support the hypotheses that perturbations in temporally correlated activity across brain regions contribute to the transition between states of sevoflurane sedation and general anaesthesia.

Cognitive Change After Cardiac Surgery Versus Cardiac Catheterization: A Population-Based Study

BACKGROUND

Despite concern that cardiac surgery may adversely affect cognition, little evidence is available from population-based studies using presurgery data. With the use of the Health and Retirement Study, we compared memory change after participant-reported cardiac catheterization or cardiac surgery.

METHODS

Participants were community-dwelling adults aged 65 years and older who self-reported cardiac catheterization or "heart surgery" at any biennial Health and Retirement Study interview between 2000 and 2014. Participants may have undergone the index procedure any time in the preceding 2 years. We modeled preprocedure to postprocedure change in composite memory score, derived from objective memory testing, using linear mixed effects models. We modeled postprocedure subjective memory decline with logistic regression. To quantify clinical relevance, we used the predicted memory change to estimate impact on ability to manage medications and finances independently.

RESULTS

Of 3,105 participants, 1,921 (62%) underwent catheterization and 1,184 (38%) underwent operation. In adjusted analyses, surgery participants had little difference in preprocedure to postprocedure memory change compared with participants undergoing cardiac catheterization (-0.021 memory units; 95% confidence interval: -0.046 to 0.005 memory units, p = 0.12). If the relationship were causal, the point estimate for memory decline would confer an absolute 0.26% or 0.19% decrease in ability to manage finances or medications, respectively, corresponding to 4.6 additional months of cognitive aging. Cardiac surgery was not associated with subjective memory decline (adjusted odds ratio 0.93, 95% confidence interval: 0.74 to 1.18).

CONCLUSIONS

In this large, population-based cohort, memory declines after heart surgery and cardiac catheterization were similar. These findings suggest intermediate-term population-level adverse cognitive effects of cardiac surgery, if any, are likely subtle.

Electroencephalography and delirium in the postoperative period

Delirium commonly manifests in the postoperative period as a clinical syndrome resulting from acute brain dysfunction or encephalopathy. Delirium is characterized by acute and often fluctuating changes in attention and cognition. Emergence delirium typically presents and resolves within minutes to hours after termination of general anaesthesia. Postoperative delirium hours to days after an invasive procedure can herald poor outcomes. Easily recognized when patients are hyperactive or agitated, delirium often evades diagnosis as it most frequently presents with hypoactivity and somnolence. EEG offers objective measurements to complement clinical assessment of this complex fluctuating disorder. Although EEG features of delirium in the postoperative period remain incompletely characterized, a shift of EEG power into low frequencies is a typical finding shared among encephalopathies that manifest with delirium. In aggregate, existing data suggest that serial or continuous EEG in the postoperative period facilitates monitoring of delirium development and severity and assists in detecting epileptic aetiologies. Future studies are needed to clarify the precise EEG features that can reliably predict or diagnose delirium in the postoperative period, and to provide mechanistic insights into this pathologically diverse neurological disorder.

Protocol for a multicentre, prospective cohort study of practice patterns and clinical outcomes associated with emergency department sedation for mechanically ventilated patients: the ED-SED Study

INTRODUCTION

In mechanically ventilated patients, sedation strategies are a major determinant of outcome. The emergency department (ED) is the earliest exposure to mechanical ventilation for hundreds of thousands of patients annually in the USA. The one retrospective study that exists regarding ED sedation for mechanically ventilated patients showed a strong association between deep sedation in the ED and worse clinical outcomes. This finding suggests that the ED may be an optimal location to study the impact of early sedation on outcome, yet a lack of prospective studies represents a knowledge gap in this arena. This protocol describes a prospective observational study aimed at further characterising ED sedation practices and assessing the relationship between ED sedation and clinical outcomes. An association between ED sedation and clinical outcomes across multiple sites would suggest the need for changes in the current sedation strategies used in the ED, and provide evidence for future interventional studies in this field.

METHODS AND ANALYSIS

This is a multicentre, prospective cohort study testing the hypothesis that deep sedation in the ED is associated with worse clinical outcomes. A cohort of over 300 mechanically ventilated ED patients will be included. The primary outcome is ventilator-free days, and secondary outcomes include hospital mortality, incidence of acute brain dysfunction and lengths of stay. Multivariable linear regression will test the hypothesis that deep sedation in the ED is associated with a decrease in ventilator-free days.

ETHICS AND DISSEMINATION

Approval of the study by the Institutional Review Board (IRB) at each participating site has been obtained prior to data collection on the first patient. This work will be disseminated by publication of peer-reviewed manuscripts, presentation in abstract form at scientific meetings and data sharing with other investigators through academically established means.

Intraoperative ketamine for prevention of depressive symptoms after major surgery in older adults: an international, multicentre, double-blind, randomised clinical trial

BACKGROUND

Ketamine is a general anaesthetic with anti-depressant effects at subanaesthetic doses. We hypothesised that intraoperative administration of ketamine would prevent or mitigate postoperative depressive symptoms in surgical patients.

METHODS

We conducted an international, randomised clinical trial testing the effects of intraoperative administration of ketamine [0.5 mg kg^-1 (Lo-K) or 1.0 mg kg^-1 (Hi-K)] vs control [saline placebo (P)] in patients ≥60 yr old undergoing major surgery with general anaesthesia. We administered the Patient Health Questionnaire-8 before the operation, on postoperative day (POD) 3 (primary outcome), and on POD30 to assess depressive symptoms, a secondary outcome of the original trial.

RESULTS

There was no significant difference on POD3 in the proportion of patients with symptoms suggestive of depression between the placebo [23/156 (14.7%)] and combined ketamine (Lo-K plus Hi-K) [61/349 (17.5%)] groups [difference = -2.7%; 95% confidence interval (CI), 5.0% to -9.4%; P=0.446]. Of the total cohort, 9.6% (64/670; 95% CI, 7.6-12.0%) had symptoms suggestive of depression before operation, which increased to 16.6% (84/505; 95% CI, 13.6-20.1%) on POD3, and decreased to 11.9% (47/395; 95% CI, 9.1-15.5%) on POD30. Of the patients with depressive symptoms on POD3 and POD30, 51% and 49%, respectively, had no prior history of depression or depressive symptoms.

CONCLUSIONS

Major surgery is associated with new-onset symptoms suggestive of depression in patients ≥60 yr old. Intraoperative administration of subanaesthetic ketamine does not appear to prevent or improve depressive symptoms.

CLINICAL TRIALS REGISTRATION

NCT01690988.

Review of perioperative falls

Falls are a known public health problem, and there is increasing recognition of the importance of perioperative falls for risk prediction and quality assessment. Our objective was to review existing literature regarding the occurrence, injuries, and risk factors of preoperative and postoperative falls. A systematized search of PubMed entries between 1947 and November 2015 produced 24 articles that met inclusion criteria. Most studied orthopaedic surgery patients older than 65 yr. Four were rated 'good' quality. Interrater reliability for the quality assessment was moderate (κ = 0.77). In the 3-12 months before surgery, the proportion of preoperative patients who fell ranged from 24 to 48%. Injuries were common (70%). The rate of postoperative falls ranged from 0.8 to 16.3 per 1000 person-days, with a gradual decline in the months after surgery. Injuries from postoperative falls occurred in 10-70% of fallers, and 5-20% experienced a severe injury. Risk factors were not well studied. Prospective studies reported a higher percentage of falls and fall-related injuries than retrospective studies, suggesting that there may be underdetection of falls and injuries with retrospective studies. Perioperative falls were more common than falls reported in the general community, even up to 12 months after surgery. Surgery-related falls may therefore occur beyond the hospitalization period. Future studies should use a prospective design, validated definitions, and broader populations to study perioperative falls. In particular, investigations of risk factors and follow-up after hospitalization are needed.

REGISTRY NUMBER

PROSPERO registration number CRD42015029971.

Study protocol for the Anesthesiology Control Tower-Feedback Alerts to Supplement Treatments (ACTFAST-3) trial: a pilot randomized controlled trial in intraoperative telemedicine

Background: Each year, over 300 million people undergo surgical procedures worldwide. Despite efforts to improve outcomes, postoperative morbidity and mortality are common. Many patients experience complications as a result of either medical error or failure to adhere to established clinical practice guidelines. This protocol describes a clinical trial comparing a telemedicine-based decision support system, the Anesthesiology Control Tower (ACT), with enhanced standard intraoperative care. Methods: This study is a pragmatic, comparative effectiveness trial that will randomize approximately 12,000 adult surgical patients on an operating room (OR) level to a control or to an intervention group. All OR clinicians will have access to decision support software within the OR as a part of enhanced standard intraoperative care. The ACT will monitor patients in both groups and will provide additional support to the clinicians assigned to intervention ORs. Primary outcomes include blood glucose management and temperature management. Secondary outcomes will include surrogate, clinical, and economic outcomes, such as incidence of intraoperative hypotension, postoperative respiratory compromise, acute kidney injury, delirium, and volatile anesthetic utilization. Ethics and dissemination: The ACTFAST-3 study has been approved by the Human Resource Protection Office (HRPO) at Washington University in St. Louis and is registered at clinicaltrials.gov ( NCT02830126). Recruitment for this protocol began in April 2017 and will end in December 2018. Dissemination of the findings of this study will occur via presentations at academic conferences, journal publications, and educational materials.

Study protocol for the Anesthesiology Control Tower-Feedback Alerts to Supplement Treatments (ACTFAST-3) trial: a pilot randomized controlled trial in intraoperative telemedicine

Background: Each year, over 300 million people undergo surgical procedures worldwide. Despite efforts to improve outcomes, postoperative morbidity and mortality are common. Many patients experience complications as a result of either medical error or failure to adhere to established clinical practice guidelines. This protocol describes a clinical trial comparing a telemedicine-based decision support system, the Anesthesiology Control Tower (ACT), with enhanced standard intraoperative care. Methods: This study is a pragmatic, comparative effectiveness trial that will randomize approximately 12,000 adult surgical patients on an operating room (OR) level to a control or to an intervention group. All OR clinicians will have access to decision support software within the OR as a part of enhanced standard intraoperative care. The ACT will monitor patients in both groups and will provide additional support to the clinicians assigned to intervention ORs. Primary outcomes include blood glucose management and temperature management. Secondary outcomes will include surrogate, clinical, and economic outcomes, such as incidence of intraoperative hypotension, postoperative respiratory compromise, acute kidney injury, delirium, and volatile anesthetic utilization. Ethics and dissemination: The ACTFAST-3 study has been approved by the Human Resource Protection Office (HRPO) at Washington University in St. Louis and is registered at clinicaltrials.gov ( NCT02830126). Recruitment for this protocol began in April 2017 and will end in December 2018. Dissemination of the findings of this study will occur via presentations at academic conferences, journal publications, and educational materials.

Obstructive sleep apnea as an independent predictor of postoperative delirium and pain: protocol for an observational study of a surgical cohort

Introduction: Postoperative delirium and pain are common complications in adults, and are difficult both to prevent and treat. Obstructive sleep apnea (OSA) is prevalent in surgical patients, and has been suggested to be a risk factor for postoperative delirium and pain. OSA also might impact pain perception, and alter pain medication requirements. This protocol describes an observational study, with the primary aim of testing whether OSA is an independent predictor of postoperative complications, focusing on (i) postoperative incident delirium and (ii) acute postoperative pain severity. We secondarily hypothesize that compliance with prescribed treatment for OSA (typically continuous positive airway pressure or CPAP) might decrease the risk of delirium and the severity of pain. Methods and analysis: We will include data from patients who have been enrolled into three prospective studies: ENGAGES, PODCAST, and SATISFY-SOS. All participants underwent general anesthesia for a non-neurosurgical inpatient operation, and had a postoperative hospital stay of at least one day at Barnes Jewish Hospital in St. Louis, Missouri, from February 2013 to May 2018.  Patients included in this study have been assessed for postoperative delirium and pain severity as part of the parent studies. In the current study, determination of delirium diagnosis will be based on the Confusion Assessment Method, and the Visual Analogue Pain Scale will be used for pain severity. Data on OSA diagnosis, OSA risk and compliance with treatment will be obtained from the preoperative assessment record. Other variables that are candidate risk factors for delirium and pain will also be extracted from this record. We will use logistic regression to test whether OSA independently predicts postoperative delirium and linear regression to assess OSAs relationship to acute pain severity. We will conduct secondary analyses with subgroups to explore whether these relationships are modified by compliance with OSA treatment.

Anesthesiology Control Tower: Feasibility Assessment to Support Translation (ACT-FAST)-a feasibility study protocol

BACKGROUND

Major postoperative morbidity and mortality remain common despite efforts to improve patient outcomes. Health information technologies have the potential to actualize advances in perioperative patient care, but failure to evaluate the usability of these technologies may hinder their implementation and acceptance. This protocol describes the usability testing of an innovative telemedicine-based intra-operative clinical support system, the Anesthesiology Control Tower, in which a team led by an attending anesthesiologist will use a combination of established and novel information technologies to provide evidence-based support to their colleagues in the operating room.

METHODS

Two phases of mixed-methods usability testing will be conducted in an iterative manner and will evaluate both the individual components of the Anesthesiology Control Tower and their integration as a whole. Phase I testing will employ two separate "think-aloud" protocol analyses with the two groups of end users. Segments will be coded and analyzed for usability issues. Phase II will involve a qualitative and quantitative in situ usability and feasibility analysis. Results from each phase will inform the revision and improvement of the Control Tower prototype throughout our testing and analysis process. The final prototype will be evaluated in the form of a pragmatic randomized controlled clinical trial.

DISCUSSION

The Anesthesiology Control Tower has the potential to revolutionize the standard of care for perioperative medicine. Through the thorough and iterative usability testing process described in this protocol, we will maximize the usefulness of this novel technology for our clinicians, thus improving our ability to implement this innovation into the model of care for perioperative medicine.

TRIAL REGISTRATION

The study that this protocol describes has been registered in clinicaltrials.gov as NCT02830126.

Intraoperative electroencephalogram suppression at lower volatile anaesthetic concentrations predicts postoperative delirium occurring in the intensive care unit

BACKGROUND

Postoperative delirium is a common complication associated with increased morbidity and mortality. A recently-reported association between intraoperative electroencephalogram suppression and postoperative delirium might be mediated in some patients by a heightened sensitivity to volatile anaesthetics.

METHODS

This retrospective cohort study included 618 elective surgery patients with planned intensive care unit admission, who also received intraoperative electroencephalogram monitoring and had delirium assessments documented in the medical record. Sensitivity to volatile anaesthetics was assessed using a mixed effects model predicting the likelihood of electroencephalogram suppression at each time point based on the current end-tidal anaesthetic concentration. Patients with a random intercept above the population median (electroencephalogram suppression at lower anaesthetic concentrations) were classified as having heightened sensitivity to volatile anaesthetics. Delirium was defined as a positive Confusion Assessment Method for the Intensive Care Unit assessment anytime in the first five postoperative days.

RESULTS

Postoperative delirium was observed in 162 of 618 patients (26%). Patients who experienced electroencephalogram suppression at lower volatile anaesthetic concentrations had a higher incidence of postoperative delirium [109/309 (35%)] than other patients [53/309 (17%)] [unadjusted odds ratio 2.63; 95% confidence interval (CI), 1.81-3.84, P<0.001]. This association remained significant after adjusting for patient characteristics, surgical variables, and duration of electroencephalogram suppression (adjusted odds ratio 2.13; 95% CI 1.24-3.65, P=0.006).

CONCLUSIONS

These data support the hypothesis that patients with electroencephalogram suppression at lower volatile anaesthetic concentrations have an increased incidence of postoperative delirium. Such patients appear to exhibit a phenotype of anaesthetic sensitivity, which might predispose them to adverse cognitive outcomes.

Cognitive and Neurophysiological Recovery Following Electroconvulsive Therapy: A Study Protocol

Electroconvulsive therapy (ECT) employs the elective induction of generalizes seizures as a potent treatment for severe psychiatric illness. As such, ECT provides an opportunity to rigorously study the recovery of consciousness, reconstitution of cognition, and electroencephalographic (EEG) activity following seizures. Fifteen patients with major depressive disorder refractory to pharmacologic therapy will be enrolled (Clinicaltrials.gov, NCT02761330). Adequate seizure duration will be confirmed following right unilateral ECT under etomidate anesthesia. Patients will then undergo randomization for the order in which they will receive three sequential treatments: etomidate + ECT, ketamine + ECT, and ketamine + sham ECT. Sessions will be repeated in the same sequence for a total of six treatments. Before each session, sensorimotor speed, working memory, and executive function will be assessed through a standardized cognitive test battery. After each treatment, the return of purposeful responsiveness to verbal command will be determined. At this point, serial cognitive assessments will begin using the same standardized test battery. The presence of delirium and changes in depression severity will also be ascertained. Sixty-four channel EEG will be acquired throughout baseline, ictal, and postictal epochs. Mixed-effects models will correlate the trajectories of cognitive recovery, clinical outcomes, and EEG metrics over time. This innovative research design will answer whether: (1) time to return of responsiveness will be prolonged with ketamine + ECT compared with ketamine + sham ECT; (2) time of restoration to baseline function in each cognitive domain will take longer after ketamine + ECT than after ketamine + sham ECT; (3) postictal delirium is associated with delayed restoration of baseline function in all cognitive domains; and (4) the sequence of reconstitution of cognitive domains following the three treatments in this study is similar to that occurring after an isoflurane general anesthetic (NCT01911195). Sub-studies will assess the relationships of cognitive recovery to the EEG preceding, concurrent, and following individual ECT sessions. Overall, this study will lead the development of biomarkers for tailoring the cogno-affective recovery of patients undergoing ECT.

Changes in quality of life after elective surgery: an observational study comparing two measures

PURPOSE

Our main objective was to compare the change in a validated quality of life measure to a global assessment measure. The secondary objectives were to estimate the minimum clinically important difference (MCID) and to describe the change in quality of life by surgical specialty.

METHODS

This prospective cohort study included 7902 adult patients undergoing elective surgery. Changes in the Veterans RAND 12-Item Health Survey (VR-12), composed of a physical component summary (PCS) and a mental component summary (MCS), were calculated using preoperative and postoperative questionnaires. The latter also contained a global assessment question for quality of life. We compared PCS and MCS to the global assessment using descriptive statistics and weighted kappa. MCID was calculated using an anchor-based approach. Analyses were pre-specified and registered (NCT02771964).

RESULTS

By the change in VR-12 scores, an equal proportion of patients experienced improvement and deterioration in quality of life (28% for PCS, 25% for MCS). In contrast, by the global assessment measure, 61% reported improvement, while only 10% reported deterioration. Agreement with the global assessment was slight for both PCS (kappa = 0.20, 57% matched) and MCS (kappa = 0.10, 54% matched). The MCID for the overall VR-12 score was approximately 2.5 points. Patients undergoing orthopedic surgery showed the most improvement in quality of life measures, while patients undergoing gastrointestinal/hepatobiliary or urologic surgery showed the most deterioration.

CONCLUSIONS

Subjective global quality of life report does not agree well with a validated quality of life instrument, perhaps due to patient over-optimism.

Intraoperative ketamine for prevention of postoperative delirium or pain after major surgery in older adults: an international, multicentre, double-blind, randomised clinical trial

BACKGROUND

Delirium is a common and serious postoperative complication. Subanaesthetic ketamine is often administered intraoperatively for postoperative analgesia, and some evidence suggests that ketamine prevents delirium. The primary purpose of this trial was to assess the effectiveness of ketamine for prevention of postoperative delirium in older adults.

METHODS

The Prevention of Delirium and Complications Associated with Surgical Treatments [PODCAST] study is a multicentre, international randomised trial that enrolled adults older than 60 years undergoing major cardiac and non-cardiac surgery under general anaesthesia. Using a computer-generated randomisation sequence we randomly assigned patients to one of three groups in blocks of 15 to receive placebo (normal saline), low-dose ketamine (0·5 mg/kg), or high dose ketamine (1·0 mg/kg) after induction of anaesthesia, before surgical incision. Participants, clinicians, and investigators were blinded to group assignment. Delirium was assessed twice daily in the first 3 postoperative days using the Confusion Assessment Method. We did analyses by intention-to-treat and assessed adverse events. This trial is registered with clinicaltrials.gov, number NCT01690988.

FINDINGS

Between Feb 6, 2014, and June 26, 2016, 1360 patients were assessed, and 672 were randomly assigned, with 222 in the placebo group, 227 in the 0·5 mg/kg ketamine group, and 223 in the 1·0 mg/kg ketamine group. There was no difference in delirium incidence between patients in the combined ketamine groups and the placebo group (19·45% vs 19·82%, respectively; absolute difference 0·36%, 95% CI -6·07 to 7·38, p=0·92). There were more postoperative hallucinations (p=0·01) and nightmares (p=0·03) with increasing ketamine doses compared with placebo. Adverse events (cardiovascular, renal, infectious, gastrointestinal, and bleeding), whether viewed individually (p value for each >0·40) or collectively (36·9% in placebo, 39·6% in 0·5 mg/kg ketamine, and 40·8% in 1·0 mg/kg ketamine groups, p=0·69), did not differ significantly across groups.

INTERPRETATION

A single subanaesthetic dose of ketamine did not decrease delirium in older adults after major surgery, and might cause harm by inducing negative experiences.

FUNDING

National Institutes of Health and Cancer Center Support.