Sedation depth during spinal anesthesia and the development of postoperative delirium in elderly patients undergoing hip fracture repair

A Comparison of Efficacy between Low-dose Dexmedetomidine and Propofol for Prophylaxis of Postoperative Delirium in Elderly Patients Undergoing Hip Fracture Surgery: A Randomized Controlled Trial

Aims and background

The efficacy of dexmedetomidine and propofol in preventing postoperative delirium is controversial. This study aims to evaluate the efficacy of dexmedetomidine and propofol for preventing postoperative delirium in extubated elderly patients undergoing hip fracture surgery.

Materials and methods

This randomized controlled trial included participants undergoing hip fracture surgery. Participants were randomly assigned to receive dexmedetomidine, propofol, or placebo intravenously during intensive care unit (ICU) admission (8 p.m. to 6 a.m.). The drug dosages were adjusted to achieve the Richmond Agitation Sedation Scale (RASS) of 0 to -1. The primary outcome was postoperative delirium. The secondary outcomes were postoperative complications, fentanyl consumption, and length of hospital stay.

Results

108 participants were enrolled (n = 36 per group). Postoperative delirium incidences were 8.3%, 22.2%, and 5.6% in the dexmedetomidine, propofol, and placebo groups, respectively. The hazard ratios of dexmedetomidine and propofol compared with placebo were 1.49 (95% CI, 0.25, 8.95; p = 0.66) and 4.18 (95% CI, 0.88, 19.69; p = 0.07). The incidence of bradycardia was higher in the dexmedetomidine group compared with others (13.9%; p = 0.01) but not for hypotension (8.3%; p = 0.32). The median length of hospital stays (8 days, IQR: 7, 11) and fentanyl consumption (240 µg, IQR: 120, 400) were not different among groups.

Conclusion

This study did not successfully demonstrate the impact of nocturnal low-dose dexmedetomidine and propofol in preventing postoperative delirium among elderly patients undergoing hip fracture surgery. While not statistically significant, it is noteworthy that propofol exhibited a comparatively higher delirium rate.

How to cite this article

Ekkapat G, Kampitak W, Theerasuwipakorn N, Kittipongpattana J, Engsusophon P, Phannajit J, et al. A Comparison of Efficacy between Low-dose Dexmedetomidine and Propofol for Prophylaxis of Postoperative Delirium in Elderly Patients Undergoing Hip Fracture Surgery: A Randomized Controlled Trial. Indian J Crit Care Med 2024;28(5):467-474.

Depth of Anesthesia and Nociception Monitoring: Current State and Vision For 2050

Anesthesia objectives have evolved into combining hypnosis, amnesia, analgesia, paralysis, and suppression of the sympathetic autonomic nervous system. Technological improvements have led to new monitoring strategies, aimed at translating a qualitative physiological state into quantitative metrics, but the optimal strategies for depth of anesthesia (DoA) and analgesia monitoring continue to stimulate debate. Historically, DoA monitoring used patient's movement as a surrogate of awareness. Pharmacokinetic models and metrics, including minimum alveolar concentration for inhaled anesthetics and target-controlled infusion models for intravenous anesthesia, provided further insights to clinicians, but electroencephalography and its derivatives (processed EEG; pEEG) offer the potential for personalization of anesthesia care. Current studies appear to affirm that pEEG monitoring decreases the quantity of anesthetics administered, diminishes postanesthesia care unit duration, and may reduce the occurrence of postoperative delirium (notwithstanding the difficulties of defining this condition). Major trials are underway to further elucidate the impact on postoperative cognitive dysfunction. In this manuscript, we discuss the Bispectral (BIS) index, Narcotrend monitor, Patient State Index, entropy-based monitoring, and Neurosense monitor, as well as middle latency evoked auditory potential, before exploring how these technologies could evolve in the upcoming years. In contrast to developments in pEEG monitors, nociception monitors remain by comparison underdeveloped and underutilized. Just as with anesthetic agents, excessive analgesia can lead to harmful side effects, whereas inadequate analgesia is associated with increased stress response, poorer hemodynamic conditions and coagulation, metabolic, and immune system dysregulation. Broadly, 3 distinct monitoring strategies have emerged: motor reflex, central nervous system, and autonomic nervous system monitoring. Generally, nociceptive monitors outperform basic clinical vital sign monitoring in reducing perioperative opioid use. This manuscript describes pupillometry, surgical pleth index, analgesia nociception index, and nociception level index, and suggest how future developments could impact their use. The final section of this review explores the profound implications of future monitoring technologies on anesthesiology practice and envisages 3 transformative scenarios: helping in creation of an optimal analgesic drug, the advent of bidirectional neuron-microelectronic interfaces, and the synergistic combination of hypnosis and virtual reality.

Combination of Pericapsular Nerve Group (PENG) and Sacral Erector Spinae Plane (S-ESP) Blocks for Hip Fracture Pain and Surgery: A Case Series

A hip fracture is a serious injury with life-threatening complications, and its risk rises with increasing age. A hip fracture can be a very painful condition, and prompt surgical treatment is recommended to reduce pain and complications. Pain management is considered integral to the management of a broken hip. The choice between general and regional anesthesia in hip fracture surgery continues to be a topic of debate because risks are potentially associated with both approaches. Nerve blockades have proven to be effective in reducing acute pain after a hip fracture and in the perioperative period. For this reason, many regional techniques have been introduced, such as the lumbar plexus block, fascia iliac block, femoral nerve block, and recently, the pericapsular nerve group (PENG) block. Hip joint innervation is complex, not limited to the lumbar plexus but also depending on the sciatic nerve and branches of the sacral plexus (superior and inferior gluteal nerves and an articular branch from the quadratus femoris nerve). We hypothesized that a combination of two emerging regional anesthesia techniques, such as the PENG block and sacral erector spinae plane (S-ESP) block, could represent a good option to obtain pain control of the whole hip joint without opioid administration intraoperatively and postoperatively. Here, we report the cases of three frail patients with significant comorbidities who underwent hip fracture surgery (two cases of intramedullary nailing and one hemiarthroplasty), in which we preoperatively performed PENG and S-ESP blocks. We registered optimal intraoperative and postoperative pain control up to 48 hours after surgery without complications and without opioid administration, allowing the surgery to be performed with intravenous sedation or laryngeal mask general anesthesia. The surgeries were uneventful, and no complications were reported. This approach warrants further investigation in hip fracture surgery.

Effect of remimazolam on electroencephalogram burst suppression in elderly patients undergoing cardiac surgery: Protocol for a randomized controlled noninferiority trial

Background

Postoperative delirium (POD) is a common complication following cardiac surgery and increases postoperative morbidity and mortality. Intraoperative electroencephalogram (EEG) burst suppression suggests excessively deep anesthesia and predicts POD. Use of remimazolam provides a stable hemodynamic status and an appropriate depth of anesthesia. We aim to assess remimazolam administered for anesthesia and sedation in elderly patients having cardiac surgery.

Methods

This is a randomized controlled clinical trial with noninferiority design. A total of 260 elderly patients aged equal to or greater than 60 years undergoing cardiac surgery will be randomly allocated to receive remimazolam or propofol (1:1) for general anesthesia and postoperative sedation until extubation. The primary outcome is the cumulative time with EEG burst suppression which is obtained from the SedLine system. The noninferiority margin is 2.0 min. The secondary outcomes include the POD occurrence within the first 5 days postoperatively and the duration of perioperative hypotension.

Discussion

This noninferiority trial is the first to evaluate the effect of perioperative remimazolam administration on EEG burst suppression, POD occurrence, and duration of hypotension in elderly patients who undergo cardiac surgery.

Trial registration

Chinese Clinical Trial Registry (ChiCTR2200056353).

Correlating the Depth of Sedation Between the Ramsay Sedation Scale and Bispectral Index Using Either Intravenous Midazolam or Intravenous Propofol in Elderly Patients Under Spinal Anaesthesia

BACKGROUND

Supplementation of spinal anaesthesia with sedatives or anxiolytics has emerged as a standard protocol to alleviate patients' anxiety and to produce amnesia during the surgical procedure. Thus, judicious use of sedation can make surgeries under spinal anaesthesia more comfortable and acceptable for the elderly patient, the surgeon, and the anaesthesiologist. However, over-sedation may jeopardise the safety of the patient. Appropriate sedation helps reduce physiological stress, which leads to a better result. Therefore, monitoring the depth of sedation becomes essential. The Ramsay sedation scale (RSS) and bispectral index (BIS) both are used widely to assess the depth of sedation.

OBJECTIVES

The primary objective of the study was to assess and correlate the depth of sedation between the BIS and RSS in elderly patients using midazolam and propofol under spinal anaesthesia. The secondary objectives were to observe any difference in the commencement of sedation between the two groups and to observe haemodynamic changes between the two groups.

METHODS

A total of 60 elderly patients undergoing urological procedures under spinal anaesthesia were randomly assigned to receive either midazolam (Group A, n=30) or propofol (Group B, n=30) for sedation. In Group A, patients were given an initial bolus of midazolam 0.03 mg/kg and a maintenance incremental bolus of 0.01 mg/kg up to a maximum of 2.5 mg in 10-minute intervals. Group B used propofol with an initial bolus dose of 0.5 mg/kg over two minutes and a maintenance bolus of 10-20 mg as required for the maintenance of sedation depth. Sedation was titrated to achieve a BIS score of 70-80 and an RSS score of 3-4. Heart rate, non-invasive systolic, diastolic, mean arterial blood pressure, oxygen saturation (SPO2), and the correlation coefficient between the BIS and RSS were measured at 0 (baseline), 5, 10, 20, 30, 40, 50, and 60 minutes of interval.

RESULTS

The correlation coefficient between the BIS and RSS scores in Group A at various time intervals indicate a strong correlation coefficient of -0.76 at five minutes, -0.64 at 20 minutes, -0.78 at 30 minutes, -0.56 at 40 minutes, and -0.39 at 50 minutes. In Group B, the correlation coefficient between the BIS and RSS scores at various time intervals indicate a strong correlation coefficient of -0.75 at five minutes, -0.76 at 20 minutes,-0.64 at 30 minutes, -0.89 at 40 minutes, and -0.46 at 50 minutes of interval. We also observed that the BIS drops to a lower level in patients receiving propofol (Group B) with a significant difference depicting early onset of sedation with propofol. In Group B, HR and MAP were significantly less than those of Group A. There was no significant difference in terms of mean age, sex, and body weight in the patients of both groups.

CONCLUSION

The BIS and RSS scores indicate a strong correlation with a magnitude of 70%-80%, but more in Group B (propofol) than Group A (midazolam). Therefore, the characteristics of each sedative drug can influence the level of sedation during spinal anaesthesia. Clinicians should use a combination of BIS values and other objective sedative methods to determine the degree of sedation, rather than relying exclusively on BIS values.

Norepinephrine prevents hypotension in older patients under spinal anesthesia with intravenous propofol sedation: a randomized controlled trial

Reducing hypotension is crucial as hypotension is the most common side effect of spinal anesthesia, and in older patients with various comorbidities, it can lead to fatality. We hypothesized that continuous infusion of norepinephrine could effectively prevent hypotension in older patients undergoing hip surgery under spinal anesthesia with propofol sedation. The study randomly assigned patients aged ≥ 70 years to either a control (Group C, n = 35) or a norepinephrine group (Group N, n = 35). After spinal anesthesia, continuous infusion of propofol and normal saline or norepinephrine was initiated. The number of hypotensive episodes, the primary outcome, as well as other intraoperative hemodynamic events and postoperative complications were compared. In total, 67 patients were included in the final analysis. The number of hypotensive episodes was significantly higher in Group C than in Group N (p < 0.001). Furthermore, Group C required a greater amount of fluid to maintain normovolemia (p = 0.008) and showed less urine output (p = 0.019). However, there was no difference in postoperative complications between the two groups. Continuous intravenous infusion of prophylactic norepinephrine prevented hypotensive episodes, reduced the requirement of fluid, and increased the urine output in older patients undergoing unilateral hip surgery under spinal anesthesia with propofol sedation.Clinical trial registration number: KCT0005046 ( https://cris.nih.go.kr ). IRB number: 2020-0533 (Institutional Review Board of Asan Medical Center, approval date: 13/APR/2020).

The effect of anesthetic depth on postoperative delirium in older adults: a systematic review and meta-analysis

BACKGROUND

Postoperative delirium (POD) is an important complication for older patients and recent randomised controlled trials have showed a conflicting result of the effect of deep and light anesthesia.

METHODS

We included randomised controlled trials including older adults that evaluated the effect of anesthetic depth on postoperative delirium from PubMed, Embase, Web of Science and Cochrane Library. We considered deep anesthesia as observer's assessment of the alertness/ sedation scale (OAA/S) of 0-2 or targeted bispectral (BIS) < 45 and the light anesthesia was considered OAA/S 3-5 or targeted BIS > 50. The primary outcome was incidence of POD within 7 days after surgery. And the secondary outcomes were mortality and cognitive function 3 months or more after surgery. The quality of evidence was assessed via the grading of recommendations assessment, development, and evaluation approach.

RESULTS

We included 6 studies represented 7736 patients aged 60 years and older. We observed that the deep anesthesia would not increase incidence of POD when compared with the light anesthesia when 4 related studies were pooled (OR, 1.40; 95% CI, 0.63-3.08, P = 0.41, I2 = 82%, low certainty). And no significant was found in mortality (OR, 1.12; 95% CI, 0.93-1.35, P = 0.23, I2 = 0%, high certainty) and cognitive function (OR, 1.13; 95% CI, 0.67-1.91, P = 0.64, I2 = 13%, high certainty) 3 months or more after surgery between deep anesthesia and light anesthesia.

CONCLUSIONS

Low-quality evidence suggests that light general anesthesia was not associated with lower POD incidence than deep general anesthesia. And High-quality evidence showed that anesthetic depth did not affect the long-term mortality and cognitive function.

SYSTEMATIC REVIEW REGISTRATION

CRD42022300829 (PROSPERO).

Pro-Con Debate: Electroencephalography-Guided Anesthesia for Reducing Postoperative Delirium

Postoperative delirium (POD) has significant implications on morbidity, mortality, and health care expenditures. Monitoring electroencephalography (EEG) to adjust anesthetic management has gained interest as a strategy to mitigate POD. In this Pro-Con commentary article, the pro side supports the use of EEG to reduce POD, citing an empiric reduction in POD with processed EEG (pEEG)-guided general anesthesia found in several studies and recent meta-analysis. The Electroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes (ENGAGES) trial is the exception to this, and issues with methods and achieved depths are discussed. Meanwhile, the Con side advocates that the use of EEG to reduce POD is not yet certain, citing that there is a lack of evidence that associations between anesthetic depth and POD represent causal relationships. The Con side also contends that the ideal EEG signatures to guide anesthetic titration are currently unknown, and the potential benefits of reduced anesthesia levels may be outweighed by the risks of potentially insufficient anesthetic administration. As the public health burden of POD increases, anesthesia clinicians will be tasked to consider interventions to mitigate risk such as EEG. This Pro-Con debate will provide 2 perspectives on the evidence and rationales for using EEG to mitigate POD.

"The Big Three" of geriatrics: A review of perioperative cognitive impairment, frailty and malnutrition

Cognitive impairment, frailty, and malnutrition are three of the most impactful pathologies facing an aging population, having dramatic effects on morbidity and mortality across nearly all facets of medical care and intervention. By 2050, the World Health Organization estimates that the population of individuals over the age of sixty worldwide will nearly double, and the public health toll of these demographic changes cannot be understated. With these changing demographics comes a need for a sharpened focus on the care and management of this vulnerable population. The average patient presenting for surgery is getting older, and this necessitates that clinicians understand the implications of these pathologies for both their immediate medical care needs and for appropriate procedural selection and prognostication of surgical outcomes. We believe it is incumbent on clinicians to consider the frailty, nutritional status, and cognitive function of each individual patient when offering a surgical intervention, as well as consider interventions that may delay the progression of these pathologies. Unfortunately, despite excellent evidence supporting things like routine pre-operative frailty screening and nutritional optimization, many interventions that would specifically benefit this population still have not been integrated into routine practice. In this review, we will synthesize the existing literature on these topics to provide a pragmatic approach and understanding for anesthesiologists and intensivists faced with this complex population.

Postoperative cognitive recovery and prevention of postoperative cognitive complications in the elderly patient

Elderly patients undergoing surgery are at higher risk of life-altering and costly complications. This challenge is increasingly recognized with the growing geriatric surgical population. Advanced age and comorbid conditions, such as disability and frailty that often develop with age, are all independent risk factors of postoperative morbidity and mortality. A common factor in this age group is cognitive impairment, which poses a challenge for the patient and clinician in the perioperative setting. It affects the capacity for informed consent and limits optimization before surgery; furthermore, an existing impairment may progress in severity during the perioperative period, and new onset of signs of delirium or postoperative cognitive dysfunction may arise during postoperative recovery. In this article, we aim to review the current literature examining the latest definitions, diagnostic criteria, and preventive strategies that may ameliorate postoperative cognitive complications.

Volatile versus intravenous anaesthesia and perioperative neurocognitive disorders: anything to see here?

There is a potential differential effect of sevoflurane compared with propofol on postoperative delirium and other perioperative neurocognitive disorders. More generally, there are perhaps differences between volatile and intravenous anaesthetic agents in their possible impact on perioperative neurocognitive disorders. Strengths and limitations of a recent study in this journal and its contribution to our understanding of the impact of anaesthetic technique on perioperative neurocognitive disorders are discussed.

Neuraxial versus general anesthesia in elderly patients undergoing hip fracture surgery and the incidence of postoperative delirium: a systematic review and stratified meta-analysis

BACKGROUND

Evidence-based effect of anesthetic regimens on postoperative delirium (POD) incidence after hip fracture surgery is still debated. Randomized trials have reported inconsistent contradictory results largely attributed to small sample size, use of outdated drugs and techniques, and inconsistent definitions of adverse outcomes. The primary objective of this meta-analysis was to investigate the impact of different anesthesia regimens on POD, cognitive impairment, and associated complications including mortality, duration of hospital stay, and rehabilitation capacity.

METHODS

We identified randomized controlled trials (RCTs) published from 2000 to December 2021, in English and non-English language, comparing the effect of neuraxial anesthesia (NA) versus general anesthesia (GA) in elderly patients undergoing hip fracture surgery, from PubMed, EMBASE, Google Scholar, Web of Science and the Cochrane Library database. They were included if POD incidence, cognitive impairment, mortality, duration of hospital stay, or rehabilitation capacity were reported as at least one of the outcomes. Study protocols, case reports, audits, editorials, commentaries, conference reports, and abstracts were excluded. Two investigators (KYC and TXY) independently screened studies for inclusion and performed data extraction. The risk of bias was assessed using the Cochrane Collaboration risk-of-bias tool. The quality of the evidence for each outcome according to the GRADE working group criteria. The odds ratio (OR) and 95% confidence intervals (CI) were calculated to assess the pooled data.

RESULTS

A total of 10 RCTs with 3968 patients were included in the present analysis. No significant differences were found in the incidence of POD comparing NA vs GA [OR 1.10, 95% CI (0.89 to 1.37)], with or without including patients with a pre-existing condition of dementia or delirium, POD incidence from postoperative day 2-7 [OR 0.31, 95% CI (0.06 to -1.63)], in mini-mental state examination (MMSE) score [OR 0.07, 95% CI (-0.22 to 0.36)], or other neuropsychological test results. NA appeared to have a shorter duration of hospital stay, especially in patients without pre-existing dementia or delirium, however the observed effect did not reach statistical significance [OR -0.23, 95% CI (-0.46 to 0.01)]. There was no difference in other outcomes, including postoperative pain control, discharge to same preadmission residence [OR 1.05, 95% CI (0.85 to 1.31)], in-hospital mortality [OR 1.98, 95% CI (0.20 to 19.25)], 30-day [OR 1.03, 95% CI (0.47 to 2.25)] or 90-day mortality [OR 1.08, 95% CI (0.53-2.24)].

CONCLUSIONS

No significant differences were detected in incidence of POD, nor in other delirium-related outcomes between NA and GA groups and in subgroup analyses. NA appeared to be associated with a shorter hospital stay, especially in patients without pre-existing dementia, but the observed effect did not reach statistical significance. Further larger prospective randomized trials investigating POD incidence and its duration and addressing long-term clinical outcomes are indicated to rule out important differences between different methods of anesthesia for hip surgery.

TRIAL REGISTRATION

10.17605/OSF.IO/3DJ6C.

A Real-Time Neurophysiologic Stress Test for the Aging Brain: Novel Perioperative and ICU Applications of EEG in Older Surgical Patients

As of 2022, individuals age 65 and older represent approximately 10% of the global population [1], and older adults make up more than one third of anesthesia and surgical cases in developed countries [2, 3]. With approximately > 234 million major surgical procedures performed annually worldwide [4], this suggests that > 70 million surgeries are performed on older adults across the globe each year. The most common postoperative complications seen in these older surgical patients are perioperative neurocognitive disorders including postoperative delirium, which are associated with an increased risk for mortality [5], greater economic burden [6, 7], and greater risk for developing long-term cognitive decline [8] such as Alzheimer's disease and/or related dementias (ADRD). Thus, anesthesia, surgery, and postoperative hospitalization have been viewed as a biological "stress test" for the aging brain, in which postoperative delirium indicates a failed stress test and consequent risk for later cognitive decline (see Fig. 3). Further, it has been hypothesized that interventions that prevent postoperative delirium might reduce the risk of long-term cognitive decline. Recent advances suggest that rather than waiting for the development of postoperative delirium to indicate whether a patient "passed" or "failed" this stress test, the status of the brain can be monitored in real-time via electroencephalography (EEG) in the perioperative period. Beyond the traditional intraoperative use of EEG monitoring for anesthetic titration, perioperative EEG may be a viable tool for identifying waveforms indicative of reduced brain integrity and potential risk for postoperative delirium and long-term cognitive decline. In principle, research incorporating routine perioperative EEG monitoring may provide insight into neuronal patterns of dysfunction associated with risk of postoperative delirium, long-term cognitive decline, or even specific types of aging-related neurodegenerative disease pathology. This research would accelerate our understanding of which waveforms or neuronal patterns necessitate diagnostic workup and intervention in the perioperative period, which could potentially reduce postoperative delirium and/or dementia risk. Thus, here we present recommendations for the use of perioperative EEG as a "predictor" of delirium and perioperative cognitive decline in older surgical patients.

The Efficacy of Low-Dose Risperidone Treatment for Post-Surgical Delirium in Elderly Orthopedic Patients

Background: Delirium is an acute and typically reversible failure of essential cognitive and attentional functions and is a growing public health concern, with an incidence of 20-50% in patients older than 65 after major surgery and 61% in patients undergoing hip fracture surgery. Numerous treatment strategies have been examined with no conclusive results. The purpose of this study is to assess the efficacy of a three-day low-dose risperidone treatment protocol, 0.5 mg BID, in treating delirium in elderly hospitalized orthopedic surgery department patients. Methods: This study is a prospective non-randomized study involving the senior patient population, older than 65, in an Orthopedic Surgery Department in 2019 and 2020. Delirium was diagnosed by a confusion assessment method (CAM) questionnaire. A three-day 0.5 mg risperidone BID treatment protocol was initiated following diagnosis. Patient data collected included age, gender, chronic diseases, type of surgery and anesthesia and delirium characteristics. Results: The delirium study group included 47 patients with an average age of 84.4 years (±8.6), of whom 53.2% were females. Delirium incidence was 3.7% in all patients older than 65 (1759 patients) and 9.3% in the proximal femoral fracture group. We did not correlate electrolyte imbalance, anemia, polypharmacy and chronic diseases to delirium onset characteristics. Following the three-day low-dose risperidone treatment protocol, 0.5 mg BID, 14.9% of the patients showed CAM score normalization after one day of treatment, and 93.6% within two days. Conclusions: We found our rigid three-day low-dose risperidone treatment protocol, 0.5 mg BID, efficacious in fast delirium resolution, without side effects.

Effect of intraoperative remimazolam on postoperative sleep quality in elderly patients after total joint arthroplasty: a randomized control trial

PURPOSE

To investigate the effect of intraoperative remimazolam sedation on postoperative sleep quality in elderly patients after total joint arthroplasty.

METHODS

Between May 15, 2021 and March 26, 2022, 108 elderly patients (age ≥ 65 years) who received total joint arthroplasty under neuraxial anesthesia were randomized into remimazolam group (a loading dose of 0.025-0.1 mg/kg and followed by an infusion rate of 0.1-1.0 mg/kg/h till end of surgery) or routine group (sedation was given on patient's requirement by dexmedetomidine 0.2-0.7 μg/kg/h). Primary outcome was the subjective sleep quality at surgery night which was evaluated by Richards Campbell Sleep Questionnaire (RCSQ). Secondary outcomes included RCSQ scores at postoperative first and second nights and numeric rating scale pain intensity within first 3 days after surgery.

RESULTS

RCSQ score at surgery night was 59 (28, 75) in remimazolam group which was comparable with 53 (28, 67) in routine group (median difference 6, 95% CI - 6 to 16, P = 0.315). After adjustment of confounders, preoperative high Pittsburg sleep quality index was associated worse RCSQ score (P = 0.032), but not remimazolam (P = 0.754). RCSQ score at postoperative first night [69 (56, 85) vs. 70 (54, 80), P = 0.472] and second night [80 (68, 87) vs. 76 (64, 84), P = 0.066] were equivalent between two groups. Safety outcomes were comparable between the two groups.

CONCLUSIONS

Intraoperative remimazolam did not significantly improve postoperative sleep quality in elderly patients undergoing total joint arthroplasty. But it is proved to be effective and safe for moderate sedation in these patients.

CLINICAL TRIAL NUMBER AND REGISTRY URL

ChiCTR2000041286 ( www.chictr.org.cn ).

The Burden of Postoperative Delirium After Shoulder Arthroplasty and Modifiable Pharmacological Perioperative Risk Factors: A Retrospective Nationwide Cohort Study

Background: Increasing demand for shoulder arthroplasty and an aging population may increase the rate of complications associated with advanced age such as postoperative delirium, but little is known on its burden in this cohort. Purpose: We sought to answer the following questions: (1) What is the epidemiology of postoperative delirium after shoulder arthroplasty? (2) What modifiable risk factors can be identified for postoperative delirium after shoulder arthroplasty? (3) Do risk factors differ in those younger than and in those older than 70 years of age? Methods: In a retrospective nationwide cohort study, we extracted data from the Premier Healthcare database on inpatient total and reverse shoulder arthroplasties from 2006 to 2016. The primary outcome was postoperative delirium; modifiable risk factors of interest were perioperative opioid use (high, medium, or low), peripheral nerve block use, and perioperative prescription medications. Mixed-effects models assessed associations between risk factors and postoperative delirium. Odds ratios and confidence intervals are reported. We applied a cutoff of 70 years of age because it was the median age of the cohort, as well as the age at which we observed that delirium prevalence increased. Results: A total of 92,429 total and reverse shoulder arthroplasties were identified (age range: 14-89 years). Overall delirium prevalence was 3.1% (n = 2909). Age-specific prevalence of postoperative delirium was lower in patients aged 50 to 70 years and higher in those aged 70 years and older, up to 8% among those older than 88 years. After adjusting for relevant covariates, only long-acting and combined short-acting and long-acting benzodiazepines (compared with no benzodiazepines) were associated with increased odds of postoperative delirium. Corticosteroids were associated with decreased odds of postoperative delirium. Conclusion: Our retrospective cohort study demonstrated that benzodiazepine use and older patient age were significantly associated with postoperative delirium in shoulder arthroplasty patients. The relationship between benzodiazepine use and delirium was particularly notable among those 70 years of age and older. Further investigation is indicated, given the known adverse effects of benzodiazepines in older adults and our findings of higher than expected use of these medications in this surgical cohort.

Effects of Earmuffs and Eye Masks on Propofol Sedation during Spinal Anesthesia for Orthopedic Surgery: A Randomized Controlled Trial

Intravenous sedative drugs are commonly administered during regional anesthesia. However, reducing the excessive use of sedatives while providing adequate sedation is important from the clinical perspective, since the use of sedatives can cause considerable complications. We hypothesized that the application of earmuffs and eye masks would help reduce the sedative dose required to maintain proper sedation by blocking external stimuli. Patients who underwent orthopedic surgery under spinal anesthesia were randomly allocated to the control (no intervention) or intervention group (wearing earmuffs and eye masks). Intravenous sedation was administered using target-controlled infusion of propofol. The target concentration was controlled to maintain a Modified Observer's Assessment of Alertness and Sedation score of 3 or 4. The primary outcome was the intraoperative propofol requirement. We also investigated the incidence of apnea, and patient satisfaction. Propofol requirement was significantly lower in the intervention group than that in the control group (2.3 (2.0-2.7) vs. 3.1 (2.7-3.4) mg·kg^-1·h^-1; p < 0.001). Intraoperative apnea occurred less frequently (p = 0.038) and patient satisfaction was higher (p = 0.002) in the intervention group compared to the control group. This study demonstrated that the use of earmuffs and eye masks during sedation was associated with lower propofol requirement and improved sedation quality.

Protocol for the electroencephalography guidance of anesthesia to alleviate geriatric syndromes (ENGAGES-Canada) study: A pragmatic, randomized clinical trial

Background:  There is some evidence that electroencephalography guidance of general anesthesia can decrease postoperative delirium after non-cardiac surgery.  There is limited evidence in this regard for cardiac surgery.  A suppressed electroencephalogram pattern, occurring with deep anesthesia, is associated with increased incidence of postoperative delirium (POD) and death.  However, it is not yet clear whether this electroencephalographic pattern reflects an underlying vulnerability associated with increased incidence of delirium and mortality, or whether it is a modifiable risk factor for these adverse outcomes. Methods:  The Electroe ncephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes ( ENGAGES-Canada) is an ongoing pragmatic 1200 patient trial at four Canadian sites.  The study compares the effect of two anesthetic management approaches on the incidence of POD after cardiac surgery.  One approach is based on current standard anesthetic practice and the other on electroencephalography guidance to reduce POD. In the guided arm, clinicians are encouraged to decrease anesthetic administration, primarily if there is electroencephalogram suppression and secondarily if the EEG index is lower than the manufacturers recommended value (bispectral index (BIS) or WAVcns below 40 or Patient State Index below 25).  The aim in the guided group is to administer the minimum concentration of anesthetic considered safe for individual patients.  The primary outcome of the study is the incidence of POD, detected using the confusion assessment method or the confusion assessment method for the intensive care unit; coupled with structured delirium chart review.  Secondary outcomes include unexpected intraoperative movement, awareness, length of intensive care unit and hospital stay, delirium severity and duration, quality of life, falls, and predictors and outcomes of perioperative distress and dissociation. Discussion:  The ENGAGES-Canada trial will help to clarify whether or not using the electroencephalogram to guide anesthetic administration during cardiac surgery decreases the incidence, severity, and duration of POD. Registration: ClinicalTrials.gov ( NCT02692300) 26/02/2016.

Protocol for the electroencephalography guidance of anesthesia to alleviate geriatric syndromes (ENGAGES-Canada) study: A pragmatic, randomized clinical trial

Background:  There is some evidence that electroencephalography guidance of general anesthesia can decrease postoperative delirium after non-cardiac surgery.  There is limited evidence in this regard for cardiac surgery.  A suppressed electroencephalogram pattern, occurring with deep anesthesia, is associated with increased incidence of postoperative delirium (POD) and death.  However, it is not yet clear whether this electroencephalographic pattern reflects an underlying vulnerability associated with increased incidence of delirium and mortality, or whether it is a modifiable risk factor for these adverse outcomes. Methods:  The Electroe ncephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes ( ENGAGES-Canada) is an ongoing pragmatic 1200 patient trial at four Canadian sites.  The study compares the effect of two anesthetic management approaches on the incidence of POD after cardiac surgery.  One approach is based on current standard anesthetic practice and the other on electroencephalography guidance to reduce POD. In the guided arm, clinicians are encouraged to decrease anesthetic administration, primarily if there is electroencephalogram suppression and secondarily if the EEG index is lower than the manufacturers recommended value (bispectral index (BIS) or WAVcns below 40 or Patient State Index below 25).  The aim in the guided group is to administer the minimum concentration of anesthetic considered safe for individual patients.  The primary outcome of the study is the incidence of POD, detected using the confusion assessment method or the confusion assessment method for the intensive care unit; coupled with structured delirium chart review.  Secondary outcomes include unexpected intraoperative movement, awareness, length of intensive care unit and hospital stay, delirium severity and duration, quality of life, falls, and predictors and outcomes of perioperative distress and dissociation. Discussion:  The ENGAGES-Canada trial will help to clarify whether or not using the electroencephalogram to guide anesthetic administration during cardiac surgery decreases the incidence, severity, and duration of POD. Registration: ClinicalTrials.gov ( NCT02692300) 26/02/2016.

A retrospective observational study on the types of anaesthesia in hip fracture surgery

BACKGROUND

There is no specific recommendation regarding the type of anaesthesia in hip fracture surgery.

OBJECTIVES

This study sought to examine the current local anaesthetic practice (general anaesthesia versus regional anaesthesia (RA)) in hip fracture surgery and to analyse their associations with perioperative outcomes.

METHODOLOGY

A retrospective observational study of hip fracture patients from April to December 2017 was undertaken. Patient characteristics and perioperative outcomes were analysed against the types of anaesthesia using multiple logistic regression.

RESULTS

One hundred and twelve out of 154 patients (72.7%) had a general anaesthesia. Patients from residential care facilities were more likely to receive general anaesthesia (OR = 2.9, 95% CI: 1.1, 7.4; P = 0.03). There was no significant association between type of anaesthesia and specific postoperative outcomes; however, patients with postoperative delirium and hypotension were more likely to have received general anaesthesia [OR = 1.7, 95% CI: 0.68, 4.38; P = 0.25] and [OR = 1.6, 95% CI: 0.67, 4.04; P = 0.27] respectively). Subgroup analysis showed increased length of stay with patients who underwent general anaesthesia (OR = 1.26, 95% CI:1.04, 1.54; P = 0.02).

CONCLUSION

Regional anaesthesia may be considered in patients without contraindications in view of increased risk of postoperative delirium and hypotension, and longer length of stay with general anaesthesia. A larger prospective study is needed to confirm these findings.

Effects of anesthetic depth on postoperative pain and delirium: a meta-analysis of randomized controlled trials with trial sequential analysis

BACKGROUND

Whether anesthetic depth affects postoperative outcomes remains controversial. This meta-analysis aimed to evaluate the effects of deep vs. light anesthesia on postoperative pain, cognitive function, recovery from anesthesia, complications, and mortality.

METHODS

PubMed, EMBASE, and Cochrane CENTRAL databases were searched until January 2022 for randomized controlled trials comparing deep and light anesthesia in adult surgical patients. The co-primary outcomes were postoperative pain and delirium (assessed using the confusion assessment method). We conducted a meta-analysis using a random-effects model. We assessed publication bias using the Begg's rank correlation test and Egger's linear regression. We evaluated the evidence using the trial sequential analysis and Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. We conducted subgroup analyses for pain scores at different postoperative time points and delirium according to cardiac or non-cardiac surgery.

RESULTS

A total of 26 trials with 10,743 patients were included. Deep anesthesia compared with light anesthesia (a mean difference in bispectral index of -12 to -11) was associated with lower pain scores at rest at 0 to 1 h postoperatively (weighted mean difference = -0.72, 95% confidence interval [CI] = -1.25 to -0.18, P  = 0.009; moderate-quality evidence) and an increased incidence of postoperative delirium (24.95% vs. 15.92%; risk ratio = 1.57, 95% CI = 1.28-1.91, P  < 0.0001; high-quality evidence). No publication bias was detected. For the exploratory secondary outcomes, deep anesthesia was associated with prolonged postoperative recovery, without affecting neurocognitive outcomes, major complications, or mortality. In the subgroup analyses, the deep anesthesia group had lower pain scores at rest and on movement during 24 h postoperatively, without statistically significant subgroup differences, and deep anesthesia was associated with an increased incidence of delirium after non-cardiac and cardiac surgeries, without statistically significant subgroup differences.

CONCLUSIONS

Deep anesthesia reduced early postoperative pain but increased postoperative delirium. The current evidence does not support the use of deep anesthesia in clinical practice.

A Multicenter, Randomized, Double-Blind, Positive-Controlled, Non-Inferiority, Phase III Clinical Trial Evaluating the Efficacy and Safety of Emulsified Isoflurane for Anesthesia Induction in Patients

BACKGROUND

Emulsified isoflurane was designed to circumvent the deficiencies of inhalation anesthetics, which have a longer time to onset, result in a higher drug consumption, and for which a specific anesthesia machine is required for clinical use. The aim of this study was to compare the efficacy and safety of emulsified isoflurane with propofol for anesthesia induction in adults patients.

METHODS

This multicenter, randomized, double-blind, positive-controlled, non-inferiority, phase III clinical trial compared the efficacy and safety of emulsified isoflurane with propofol for anesthesia induction. Each patient in the emulsified isoflurane group received a single bolus injection of 12% emulsified isoflurane at a dose of 30 mg/kg, and each patient in the propofol group received a single bolus injection of 0.8% propofol at a dose of 2 mg/kg. The primary outcome of the efficacy evaluation was the proportion of participants with successful anesthesia induction, which was regarded as a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of < 1 and lack of use of other sedative drugs. A number of secondary efficacy outcomes were also assessed. Safety was monitored based on (1) adverse events, (2) repeated measurement of vital signs; (3) physical examination, (4) routine laboratory examinations of hematology, biochemistry, urine, coagulation function, and (5) 12-lead electrocardiogram.

RESULTS

A total of 416 patients were enrolled (n = 208 in each group) and 398 patients were administered study drug. The proportion of participants with successful anesthesia induction was 100% with a 95% confidence interval of - 1.9% to + 1.9% for the emulsified isoflurane and propofol groups, which met the predesigned non-inferiority criteria of 5%. The study demonstrated the non-inferiority of sedation produced by emulsified isoflurane compared to propofol. Among the secondary efficacy outcomes, emulsified isoflurane showed a better cardiovascular stability than propofol. The number of patients from the emulsified isoflurane group who experienced drug-related adverse events was significantly higher than that of patients from the propofol group. However, there was no significant difference between the two groups in terms of adverse events or drug-related adverse events of grades 3-5.

CONCLUSIONS

Emulsified isoflurane exhibited non-inferiority of anesthesia/sedation compared to propofol in patients undergoing anesthesia induction.

CLINICAL TRIAL REGISTRATION

ChiCTR2000038185, registered on 12 December, 2020 ( www.chictr.org.cn ).

Virtual reality immersion compared to monitored anesthesia care for hand surgery: A randomized controlled trial

Introduction

Common anesthesia practice for hand surgery combines a preoperative regional anesthetic and intraoperative monitored anesthesia care (MAC). Despite adequate regional anesthesia, patients may receive doses of intraoperative sedatives which can result in oversedation and potentially avoidable complications. VR could prove to be a valuable tool for patients and providers by distracting the mind from processing noxious stimuli resulting in minimized sedative use and reduced risk of oversedation without negatively impacting patient satisfaction. Our hypothesis was that intraoperative VR use reduces sedative dosing during elective hand surgery without detracting from patient satisfaction as compared to a usual care control.

Methods

Forty adults undergoing hand surgery were randomized to receive either intraoperative VR in addition to MAC, or usual MAC. Patients in both groups received preoperative regional anesthesia at provider discretion. Intraoperatively, the VR group viewed programming of their choice via a head-mounted display. The primary outcome was intraoperative propofol dose per hour (mg · hr^-1). Secondary outcomes included patient reported pain and anxiety, overall satisfaction, functional outcome, and post anesthesia care unit (PACU) length of stay (LOS).

Results

Of the 40 enrolled patients, 34 completed the perioperative portion of the trial. VR group patients received significantly less propofol per hour than the control group (Mean (±SD): 125.3 (±296.0) vs 750.6 (±334.6) mg · hr^-1, p<0.001). There were no significant differences between groups in patient reported overall satisfaction, (0–100 scale, Median (IQR) 92 (77–100) vs 100 (100–100), VR vs control, p = 0.087). There were no significant differences between groups in PACU pain scores, perioperative opioid analgesic dose, or in postoperative functional outcome. PACU LOS was significantly decreased in the VR group (53.0 (43.0–72.0) vs 75.0 (57.5–89.0) min, p = 0.018).

Conclusion

VR immersion during hand surgery led to significant reductions in intraoperative propofol dose and PACU LOS without negatively impacting key patient reported outcomes.

Prevalence of Emergence Delirium and Associated Factors among Older Patients Who Underwent Elective Surgery: A Multicenter Observational Study

Background

Emergence delirium is a common and serious postoperative complication in older surgical patients. It occurs at any time in the perioperative period, during or immediately following emergence from general anesthesia. Unfortunately, it is highly associated with postoperative complications such as a decrease in functional capacity, prolonged hospital stay, an increase in health care costs, and morbidity and mortality. The goal of this study was to determine the prevalence of emergence delirium and associated factors among older patients who underwent elective surgery in the teaching hospitals of Ethiopia at the postanesthesia care unit in 2021.

Methods

A multicenter prospective observational study was conducted at the postanesthetic care unit in the four teaching hospitals of Ethiopia. Older surgical patients admitted to the postanesthesia care unit who underwent elective surgery in the four teaching hospitals of Ethiopia were selected by using simple random sampling. Pretested structured questionnaire was used to collect data. Data were entered into EpiData (version 4.6) and exported to the SPSS (version 25.0). Binary logistic regression was used to identify factors independently associated with the emergence delirium.

Results

Out of 384 older patients included in the study, the prevalence of emergence delirium was 27.6%. Preoperative low hemoglobin levels (AOR: 2.0, 95% CI; 1.77–3.46), opioid (AOR: 8.0, 95% CI; 3.22–27.8), anticholinergic premedications (AOR: 8.5, 95% CI; 6.85–17.35), and postoperative pain (AOR: 3.10, 95 CI; 2.07–9.84) at PACU were independently associated with emergence delirium.

Conclusion

The prevalence of emergence delirium was high among older patients who underwent elective surgery. Opioid and anticholinergic premedication, low preoperative hemoglobin, and the presence of postoperative pain were independently associated with the emergence delirium. Adequate preoperative optimization and postoperative analgesia may reduce the prevalence of emergence delirium.

Effect of regional anesthesia on the postoperative delirium: A systematic review and meta-analysis of randomized controlled trials

Objective

Postoperative delirium (POD) starts in the recovery room and occurs up to 5 days after surgery. However, the POD guidelines issued by the European Society of Anesthesiology (ESA) suggest that the effect of regional anesthesia on POD is controversial. This meta-analysis aims to investigate whether perioperative regional anesthesia reduced the incidence of POD.

Methods

Standard Published randomized controlled trails (RCTs) were searched from bibliographic databases to identify all evidence that reported regional anesthesia assessing incident delirium following diverse surgeries. The primary outcome was the incidence of POD, and the secondary outcomes were POD scores, pain scores, and emergence time. The relative risk (RR) for dichotomous outcomes and the weighted or standardized mean difference (WMD, SMD) for continuous outcomes were estimated using a random-effects model.

Results

Twenty RCTs with 2110 randomized participants undergoing different surgeries were included. Meta-analysis showed that regional anesthesia was associated with less POD incidence compared to general anesthesia (total intravenous anesthesia (TIVA) or inhalation anesthesia) (relative risk (RR) = 0.62, 95% confidence interval (CI) = 0.45–0.85)). Subgroup analysis showed that the decrease in POD incidence was associated with a nerve block (0.46, 95% CI = 0.32–0.67) and regional-combined-general anesthesia (0.42, 95% CI = 0.29–0.60). Regional anesthesia significantly reduced POD incidence in the recovery room after pediatric surgeries (0.41, 95% CI = 0.29–0.56). Regional anesthesia also reduced the POD score (SMD −0.93, 95% CI = −1.55 to −0.31) and pain score (SMD −0.95, 95% CI = −1.72 to −0.81). There was no significant difference in emergence time between regional anesthesia and general anesthesia (WMD −1.40, 95% CI = −3.83 to 6.63).

Conclusions

There was a significant correlation between regional anesthesia and the decrease in POD incidence, POD score, and pain score.

Perioperative Brain Health in the Older Adult: A Patient Safety Imperative

While people 65 years of age and older represent 16% of the population in the United States, they account for >40% of surgical procedures performed each year. Maintaining brain health after anesthesia and surgery is not only important to our patients, but it is also an increasingly important patient safety imperative for the specialty of anesthesiology. Aging is a complex process that diminishes the reserve of every organ system and often results in a patient who is vulnerable to the stress of surgery. The brain is no exception, and many older patients present with preoperative cognitive impairment that is undiagnosed. As we age, a number of changes occur in the human brain, resulting in a patient who is less resilient to perioperative stress, making older adults more susceptible to the phenotypic expression of perioperative neurocognitive disorders. This review summarizes the current scientific and clinical understanding of perioperative neurocognitive disorders and recommends patient-centered, age-focused interventions that can better mitigate risk, prevent harm, and improve outcomes for our patients. Finally, it discusses the emerging topic of sleep and cognitive health and other future frontiers of scientific inquiry that might inform clinical best practices.

Efficacy of Bioenergetic Health Index to Predict Delirium After Major Abdominal Surgery in Elderly Patients: A Protocol for a Prospective Observational Cohort Study

Introduction

Postoperative delirium (POD) is a common disorder following surgery, which seriously threatens the quality of patients’ life, especially the older people. The multifactorial manner of this syndrome has made it hard to define an ideal method to predict individual risk. Mitochondria play a key role in the process of POD, which include inflammatory on the brain caused by surgeries and aging related neurodegeneration. As BHI (Bioenergetic Health Index) could be calculated in cells isolated from an individual’s blood to represent the patient’s composite mitochondrial statue, we hypotheses that HBI of monocytes isolated from individual’s peripheral blood can predict POD after major non-cardiac surgery in elderly patients.

Methods and Analysis

This is a prospective, observational single-blinded study in a single center. 124 patients aged ≥ 65 years and scheduled for major abdominal surgery (&gt;3 h) under general anesthesia will be enrolled. Preoperative and postoperative delirium will be assessed by trained members using Confusion Assessment Method (CAM). For patients unable to speak in the ICU after the surgery, Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) will be used. All patients will undergo venous blood sampling twice to measure BHI (1–2 tubes, 5 ml/tube): before the surgery and 1 day after surgery in wards. After discharge, patients will be contacted by telephone 30 days after surgery to confirm the incidence of post-discharge complications. The severity of complications will be categorized as mild, moderate, severe or fatal using a modified Clavien-Dindo Classification (CDC) scheme.

Ethics and Dissemination

The study has been approved by the Ethics Committee on Biomedical Research, West China Hospital of Sichuan University, Sichuan, China (Chairperson Prof Shaolin Deng, No. 2021-502). Study data will be disseminated in manuscripts submitted to peer-reviewed medical journals as well as in abstracts submitted to congresses.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [ChiCTR2100047554].

Review of Postoperative Delirium in Geriatric Patients After Hip Fracture Treatment

Introduction

Postoperative delirium (POD) is a serious complication occurring in 4–53.3% of geriatric patients undergoing surgeries for hip fracture. Incidence of hip fractures is projected to grow 11.9% from 258,000 in 2010 to 289,000 in 2030 based on 1990 to 2010 data. As prevalence of hip fractures is projected to increase, POD is also anticipated to increase.

Signficance

Postoperative delirium remains the most common complication of emergency hip fracture surgery leading to high morbidity and mortality rates despite significant research conducted regarding this topic. This study reviews literature from 1990 to 2021 regarding POD in geriatric hip fracture management.

Results

Potentially modifiable and non-modifiable risk factors for developing POD include, but are not limited to, male gender, older age, multiple comorbidities, specific comorbidities (dementia, cognitive impairment, diabetes, vision impairment, and abnormal blood pressure), low BMI, preoperative malnutrition, low albumin, low hematocrit, blunted preoperative cytokines, emergency surgery, time to admission and surgery, preoperative medical treatment, polypharmacy, delirium-inducing medications, fever, anesthesia time, and sedation depth and type. Although the pathophysiology remains unclear, the leading theories suggest neurotransmitter imbalance, inflammation, and electrolyte or metabolic derangements as the underlying cause of POD. POD is associated with increased length of hospital stay, cost, morbidity, and mortality. Prevention and early recognition are key factors in managing POD. Methods to reduce POD include utilizing interdisciplinary teams, educational programs for healthcare professionals, reducing narcotic use, avoiding delirium-inducing medications, and multimodal pain control.

Conclusion

While POD is a known complication after hip fracture surgery, further exploration in prevention is needed. Early identification of risk factors is imperative to prevent POD in geriatric patients. Early prevention will enhance delivery of health care both pre- and post-operatively leading to the best possible surgical outcome and better quality of life after hip fracture treatment.

Spectral Entropy Monitoring Accelerates the Emergence from Sevoflurane Anesthesia in Thoracic Surgery: A Randomized Controlled Trial

The clinical efficacy of spectral entropy monitoring in improving postoperative recovery remains unclear. This trial aimed to investigate the impact of M-Entropy (GE Healthcare, Helsinki, Finland) guidance on emergence from anesthesia and postoperative delirium in thoracic surgery. Adult patients undergoing video-assisted thoracoscopic surgery for lung resection at a medical center were randomly allocated into the M-Entropy guidance group (n = 39) and the control group (n = 37). In the M-Entropy guidance group, sevoflurane anesthesia was titrated to maintain response and state entropy values between 40 and 60 intraoperatively. In the control group, the dosing of sevoflurane was adjusted based on clinical judgment and vital signs. The primary outcome was time to spontaneous eye opening. M-Entropy guidance significantly reduced the time proportion of deep anesthesia (entropy value <40) during surgery, mean difference: −21.5% (95% confidence interval (CI): −32.7 to −10.3) for response entropy and −24.2% (−36.3 to −12.2) for state entropy. M-Entropy guidance significantly shortened time to spontaneous eye opening compared to clinical signs, mean difference: −154 s (95% CI: −259 to −49). In addition, patients of the M-Entropy group had a lower rate of emergence agitation (absolute risk reduction: 0.166, 95% CI: 0.005−0.328) and delirium (0.245, 0.093−0.396) at the postanesthesia care unit. M-Entropy-guided anesthesia hastened awakening and potentially prevented emergence agitation and delirium after thoracic surgery. These results may provide an implication for facilitating postoperative recovery and reducing the complications associated with delayed emergence and delirium.

Quo Vadis Anesthesiologist? The Value Proposition of Future Anesthesiologists Lies in Preserving or Restoring Presurgical Health after Surgical Insult

This Special Issue of the Journal of Clinical Medicine is devoted to anesthesia and perioperative care [...].

Electroencephalographic Burst-Suppression, Perioperative Neuroprotection, Postoperative Cognitive Function, and Mortality: A Focused Narrative Review of the Literature

Burst-suppression is an electroencephalographic pattern that results from a diverse array of pathophysiological causes and/or metabolic neuronal suppression secondary to the administration of anesthetic medications. The purpose of this review is to provide an overview of the physiological mechanisms that underlie the burst-suppression pattern and to present in a comprehensive way the available evidence both supporting and in opposition to the clinical use of this electroencephalographic pattern as a therapeutic measure in various perioperative settings.

Spinal Anesthesia with Targeted Sedation based on Bispectral Index Values Compared with General Anesthesia with Masked Bispectral Index Values to Reduce Delirium: The SHARP Randomized Controlled Trial

BACKGROUND

Reducing depth of anesthesia and anesthetic exposure may help prevent delirium, but trials have been conflicting. Most studies were conducted under general anesthesia or in cognitively impaired patients. It is unclear whether reducing depth of anesthesia beyond levels consistent with general anesthesia reduces delirium in cognitively intact patients. The authors' objective was to determine whether a bundled approach to reduce anesthetic agent exposure as determined by Bispectral Index (BIS) values (spinal anesthesia with targeted sedation based on BIS values) compared with general anesthesia (masked BIS) reduces delirium.

METHODS

Important eligibility criteria for this parallel-arm randomized trial were patients 65 yr or greater undergoing lumbar spine fusion. The intervention group received spinal anesthesia with targeted sedation to BIS greater than 60 to 70. The control group received general anesthesia (masked BIS). The primary outcome was delirium using the Confusion Assessment Method daily through postoperative day 3, with blinded assessment.

RESULTS

The median age of 217 patients in the analysis was 72 (interquartile range, 69 to 77). The median BIS value in the spinal anesthesia with targeted sedation based on BIS values group was 62 (interquartile range, 53 to 70) and in the general anesthesia with masked BIS values group was 45 (interquartile range, 41 to 50; P < 0.001). Incident delirium was not different in the spinal anesthesia with targeted sedation based on BIS values group (25.2% [28 of 111] vs. the general anesthesia with masked BIS values group (18.9% [20 of 106]; P = 0.259; relative risk, 1.22 [95% CI, 0.85 to 1.76]). In prespecified subgroup analyses, the effect of anesthetic strategy differed according to the Mini-Mental State Examination, but not the Charlson Comorbidity Index or age. Two strokes occurred among patients receiving spinal anesthesia and one death among patients receiving general anesthesia.

CONCLUSIONS

Spinal anesthesia with targeted sedation based on BIS values compared with general anesthesia with masked BIS values did not reduce delirium after lumbar fusion.

EDITOR’S PERSPECTIVE

[Intraoperative Neuromonitoring: Electroencephalography]

Intraoperative neuromonitoring using electroencephalography (EEG) enables anaesthesiologists to monitor the depth of anaesthesia. It is intended to reduce the occurrence of intraoperative wakefulness, postoperative delirium and postoperative cognitive deficits and to shorten process times in the operating room. This article shows how to interpret the raw EEG, spectrograms and processed indices for different age groups and anaesthetics and summarizes the resulting clinical benefits. While propofol and volatile anesthetics produce characteristic frontal EEG signatures with a high activity of coherent α- and δ-waves, ketamine triggers an increase in rapid γ-waves, which leads to incorrectly high indices (BIS, PSI, NI) despite deep anaesthetic levels.In children, frontal α-waves do not appear until the age of approx. 6 months and valid indices (BIS, PSI, NI) can only be derived starting at an age of approx. 12 months. Furthermore, children of preschool and elementary school age often show epileptiform discharges in the EEG during induction of anaesthesia, what is linked to emergence delirium. In adults, the intraoperative frontal α-power decreases significantly with increasing age and older patients tend to have an increased occurrence of burst suppression patterns during anaesthesia. Clinical benefits of EEG-based neuromonitoring comprise reduced doses of anaesthesia, shorter wake-up times after surgery and a lower incidence of intraoperative awareness during total intravenous anaesthesia. Moreover, anaesthesia guided by processed EEG indices can reduce the incidence of postoperative delirium and postoperative cognitive deficits in older patients. In-depth knowledge about intraoperative EEG changes that go beyond the interpretation of processed indices could lead to a further reduction in intra- and postoperative complications in the future.

Verification of the performance of the Bispectral Index as a hypnotic depth indicator during dexmedetomidine sedation

Background

Differences in the effects of propofol and dexmedetomidine sedation on electroencephalogram patterns have been reported previously. However, the reliability of the Bispectral Index (BIS) value for assessing the sedation caused by dexmedetomidine remains debatable. The purpose of this study is to evaluate the correlation between the BIS value and the Modified Observer’s Assessment of Alertness/Sedation (MOAA/S) scale in patients sedated with dexmedetomidine.

Methods

Forty-two patients aged 20–80 years, who were scheduled for surgery under spinal anesthesia were enrolled. Spinal anesthesia was performed using 0.5% bupivacaine, which was followed by dexmedetomidine infusion (loading dose, 0.5–1 μg/kg for 10 min; maintenance dose, 0.3–0.6 μg/kg/h). The MOAA/S score was used to evaluate the level of sedation.

Results

A total of 215082 MOAA/S scores and BIS data pairs were analyzed. The baseline variability of the BIS value was 7.024%, and BIS value decreased, as the MOAA/S scored decreased. The correlation coefficient and prediction probability between the two measurements were 0.566 (P < 0.0001) and 0.636, respectively. The mean ± standard deviation values of the BIS were 87.22 ± 7.06, 75.85 ± 9.81, and 68.29 ± 12.65 when the MOAA/S scores were 5, 3, and 1, respectively. Furthermore, the cut-off BIS values in the receiver operating characteristic analysis at MOAA/S scores of 5, 3, and 1 were 82, 79, and 73, respectively.

Conclusions

The BIS values were significantly correlated with the MOAA/S scores. Thus, the BIS along with the clinical sedation scale might prove useful in assessing the hypnotic depth of a patient during sedation with dexmedetomidine.

Lack of Association Between Perioperative Medication and Postoperative Delirium in Hip Fracture Patients in an Orthogeriatric Care Pathway

OBJECTIVES

Units for perioperative geriatric care are playing a growing role in the care of older patients after hip fracture surgery. Postoperative delirium is one of the most common complications after hip fracture, but no study has assessed the impact of therapeutics received during a dedicated orthogeriatric care pathway on its incidence. Our main objective was to assess the association between drugs used in emergency, operating, and recovery departments and postoperative delirium during the acute stay.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

All patients ≥70 years old admitted for hip fracture to the emergency department and hospitalized in our unit for perioperative geriatric care after hip fracture surgery under general anesthesia between July 2009 and December 2019 in an academic hospital in Paris.

METHODS

Demographic, clinical, and biological data and all medications administered pre-, peri-, and postoperatively were prospectively collected by 3 geriatricians. Postoperative delirium in the unit for perioperative geriatric care was assessed by using the confusion assessment method scale. Logistic regression analysis was used to assess variables independently associated with postoperative delirium.

RESULTS

A total of 490 patients were included [mean (SD) age 87 (6) years]; 215 (44%) had postoperative delirium. The occurrence was not associated with therapeutics administered during the dedicated orthogeriatric care pathway. Probability of postoperative delirium was associated with advanced age [>90 years, odds ratio (OR) 2.03, 95% confidence interval (CI) 1.07-3.89], dementia (OR 3.51, 95% CI 2.14--5.82), depression (OR 1.85, 95% CI 1.14-3.01), and preoperative use of beta-blockers (OR 1.75, 95% CI 1.10-2.79).

CONCLUSIONS AND IMPLICATIONS

No emergency or anesthetic drugs were significantly associated with postoperative delirium. Further studies are needed to demonstrate a possible causal link between preoperative use of beta-blockers and postoperative delirium.

Emergence Delirium in a 29-Year-Old Man following an Uneventful Appendectomy

Emergence delirium (ED) is defined as the delirium that occurs during the transition from the sleep state to full consciousness. ED increases the risk for injury, self-extubation, hemorrhages, and prolonged hospitalization and occurs in patients of any age but most often in children and elderly patients. However, ED in young adults is rarely reported. We presented a case of typical ED occurring in a young healthy man following an uneventful appendectomy. The causes of ED can be classified as either predisposing or precipitating factors. In this case, the unnoticeable mental stress may be the predisposing factor and the sevoflurane maintenance of anesthesia may be the precipitating factor. ED occurs at any age of patient and in any minor surgery, and anesthesiologists should do some work to prevent it from happening.

Immersive Virtual Reality Used as Adjunct Anesthesia for Conversion Total Hip Arthroplasty in a 100-Year-Old Patient

Immersive virtual reality (IVR) is an adjunctive form of anesthesia intended to distract patients from their intraoperative environment and reduce other side effects of sedating or narcotic agents. While this technology has been applied sparingly in various orthopedic procedural environments, its clinical utility has not been widely evaluated in major, nonelective surgical settings. The use of IVR in the geriatric hip fracture population represents a novel indication with potential benefit to reduced cognitive dysfunction and delirium. We report a case of a 100-year-old patient who received IVR adjunctive to neuraxial anesthesia during conversion total hip arthroplasty via posterolateral approach for treatment of failed peritrochanteric hip fracture fixation.

Preoperative Sedative-hypnotic Medication Use and Adverse Postoperative Outcomes

OBJECTIVE

To determine the association between preoperative benzodiazepine and nonbenzodiazepine receptor agonist ("Z-drugs") use and adverse outcomes after surgery.

BACKGROUND

Prescriptions for benzodiazepines and Z-drugs have increased over the past decade. Despite this, the association of preoperative benzodiazepines and Z-drug receipt with adverse outcomes after surgery is unknown.

METHODS

Using the Optum Clinformatics Datamart, we performed a retrospective cohort study of adults 18 years or older who underwent any of 10 common surgical procedures between 2010 and 2015. The principal exposure was one or more filled prescriptions for a benzodiazepine or Z-drug in the 90 days before surgery. The primary outcome was any emergency department visit or hospital admission for either (1) a drug related adverse medical event or overdose or (2) a traumatic injury in the 30 days after surgery.

RESULTS

Of 785,346 patients meeting inclusion criteria, 94,887 (12.1%) filled a preoperative prescription for a benzodiazepine or Z-drug. From multivariable logistic regression, benzodiazepine or Z-drug use was associated with an increased odds of an adverse postoperative event [odds ratio 1.13; 95% confidence interval: 1.08-1.18). In a separate regression, coprescription of benzodiazepines or Z-drugs with opioids was associated with a 1.45 odds of an adverse postoperative event (95% confidence interval: 1.37-1.53).

CONCLUSIONS

Preoperative benzodiazepines and Z-drug use is common and associated with increased odds of adverse outcomes after surgery, particularly when coprescribed with opioids. Counseling on appropriate benzodiazepine and Z-drug use in advance of elective surgery may potentially increase the safety of surgical care.

Effects of perioperative interventions for preventing postoperative delirium: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Postoperative delirium (POD) not only increases the medical burden but also adversely affects patient prognosis. Although some cases of delirium can be avoided by early intervention, there is no clear evidence indicating whether any of these measures can effectively prevent POD in specific patient groups.

OBJECTIVE

The aim of this meta-analysis was to compare the efficacy and safety of the existing preventive measures for managing POD.

METHODS

The PubMed, OVID (Embase and MEDLINE), Web of Science, and the Cochrane Library databases were searched for articles published before January 2020. The relevant randomized controlled trials (RCTs) were selected based on the inclusion and exclusion criteria. Data extraction and methodological quality assessment were performed according to a predesigned data extraction form and scoring system, respectively. The interventions were compared on the basis of the primary outcome like incidence of POD, and secondary outcomes like duration of delirium and the length of intensive care unit and hospital stay.

RESULTS

Sixty-three RCTs were included in the study, covering interventions like surgery, anesthesia, analgesics, intraoperative blood glucose control, cholinesterase inhibitors, anticonvulsant drugs, antipsychotic drugs, sleep rhythmic regulation, and multi-modal nursing. The occurrence of POD was low in 4 trials that monitored the depth of anesthesia with bispectral index during the operation (P < .0001). Two studies showed that supplementary analgesia was useful for delirium prevention (P = .002). Seventeen studies showed that perioperative sedation with α2-adrenergic receptor agonists prevented POD (P = .0006). Six studies showed that both typical and atypical antipsychotic drugs can reduce the incidence of POD (P = .002). Multimodal nursing during the perioperative period effectively reduced POD in 6 studies (P < .00001). Furthermore, these preventive measures can reduce the duration of delirium, as well as the total and postoperative length of hospitalized stay for non-cardiac surgery patients. For patients undergoing cardiac surgery, effective prevention can only reduce the length of intensive care unit stay.

CONCLUSION

Measures including intraoperative monitoring of bispectral index, supplemental analgesia, α2-adrenergic receptor agonists, antipsychotic drugs, and multimodal care are helpful to prevent POD effectively. However, larger, high-quality RCTs are needed to verify these findings and develop more interventions and drugs for preventing postoperative delirium.

Processed Multiparameter Electroencephalogram-Guided General Anesthesia Management Can Reduce Postoperative Delirium Following Carotid Endarterectomy: A Randomized Clinical Trial

Background: Patients undergoing carotid endarterectomy (CEA) for severe carotid stenosis are vulnerable to postoperative delirium, a complication frequently associated with poor outcome. This study investigated the impact of processed electroencephalogram (EEG)-guided anesthesia management on the incidence of postoperative delirium in patients undergoing CEA.

Methods: This single-center, prospective, randomized clinical trial on 255 patients receiving CEA under general anesthesia compared the outcomes of patient state index (PSI) monitoring [SEDLine Brain Function Monitor (Masimo, Inc, Irvine, CA)] (standard group, n = 128) with PSI combined with density spectral array(DSA) -guided monitoring (intervention group, n = 127) to reduce the risk of intraoperative EEG burst suppression. All patients were monitored by continuous transcranial Doppler ultrasound (TCD) and near-infrared spectroscopy (NIRS) to avoid perioperative cerebral hypoperfusion or hyperperfusion. According to the surgical process, EEG suppression time was calculated separately for three stages: S₁ (from anesthesia induction to carotid artery clamping), S₂ (from clamping to declamping), and S₃ (from declamping to the end of surgery). The primary outcome was incidence of postoperative delirium according to the Confusion Assessment Method algorithm during the first 3 days post-surgery, and secondary outcomes were other neurologic complications and length of hospital stay.

Results: There were no episodes of cerebral hypoperfusion or hyperperfusion according to TCD and NIRS monitoring in either group during surgery. The incidence of postoperative delirium within 3 days post-surgery was significantly lower in the intervention group than the standard group (7.87 vs. 28.91%, P < 0.01). In the intervention group, the total EEG suppression time and the EEG suppression time during S2 and S3 were shorter (Total, 0 “0” vs. 0 “1.17” min, P = 0.04; S₂, 0 “0” vs. 0 “0.1” min, P < 0.01; S₃, 0 “0” vs. 0 “0” min, P = 0.02). There were no group differences in incidence of neurologic complications and length of postoperative hospital stay.

Conclusion: Processed electroencephalogram-guided general anesthesia management, consisting of PSI combined with DSA monitoring, can significantly reduce the risk of postoperative delirium in patients undergoing CEA. Patients, especially those exhibiting hemodynamic fluctuations or receiving surgical procedures that disrupt cerebral perfusion, may benefit from the monitoring of multiple EEG parameters during surgery.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT03622515.

Where should patients with or at risk of delirium be treated in an acute care system? Comparing the rates of delirium in patients receiving usual care vs alternative care: A systematic review and meta-analysis

BACKGROUND

Delirium is an acute condition that occurs in hospitalised patients and leads to poor patient outcomes that can last long term. Therefore, the importance of prevention is undeniable and adopting new models of care for at-risk patients should be prioritised.

OBJECTIVES

This systematic review and meta-analysis will assess the effectiveness of different interventions designed to prevent or manage delirium in acutely unwell hospitalised patients.

METHODS

MEDLINE, EMBASE, PsycINFO, OpenGrey, Web of Science and reference lists of journals were searched. Eligible studies reported on incidence or duration of delirium, used a validated delirium diagnostic tool and compared an intervention to either a control or another intervention group. Meta-analyses were conducted, and GRADEpro software was used to assess the certainty of evidence. This review is registered on PROSPERO.

RESULTS

A total of 59 studies were included and 33 were eligible for meta-analysis. Delirium incidence was most significantly reduced by non-pharmacological multicomponent interventions compared with usual care, with pooled risk ratios of 0.57 (95% CI: 0.44 to 0.73, 10 randomised controlled trials) and 0.47 (95% CI: 0.35 to 0.64, six observational studies). Single-component interventions did not significantly reduce delirium incidence compared with usual care in seven randomised trials (risk ratio = 0.92, 95% CI: 0.81 to 1.04). The most effective single-component intervention in reducing delirium incidence was a hospital-at-home intervention (risk ratio = 0.29, 95% CI: 0.09 to 0.87).

CONCLUSIONS

Non-pharmacological multicomponent interventions are effective in preventing delirium; however, the same cannot be said for other interventions because of uncertain results. There is some evidence that providing multicomponent interventions in patients' homes is more effective than in a hospital setting. Therefore, researching the benefits of hospital-at-home interventions in delirium prevention is recommended.

The association of bispectral index values and metrics of cerebral perfusion during cardiopulmonary bypass

STUDY OBJECTIVE

Low bispectral index (BIS) values have been associated with adverse postoperative outcomes. However, trials of optimizing BIS by titrating anesthetic administration have reported conflicting results. One potential explanation is that cerebral perfusion may also affect BIS, but the extent of this relationship is not clear. Therefore, we examined whether BIS would be associated with cerebral perfusion during cardiopulmonary bypass, when anesthetic concentration was constant.

DESIGN

Observational cohort study.

SETTING

Cardiac operating room.

PATIENTS

Seventy-nine patients with cardiopulmonary bypass surgery were included.

MEASUREMENTS

Continuous BIS, mean arterial blood pressure (MAP), cerebral blood flow velocity (CBFV), and regional cerebral oxygen saturation (rSO₂) were monitored, with analysis during a period of constant anesthetic. Mean flow index (Mx) was calculated as Pearson correlation between MAP and CBFV. The lower limit of autoregulation (LLA) was identified as the MAP value at which Mx increased >0.4 with decreasing blood pressure. Postoperative delirium was assessed using the 3D-Confusion Assessment Method.

RESULTS

Mean BIS was lower during periods of MAP < LLA compared with BIS when MAP>LLA (mean 49.35 ± 10.40 vs. 50.72 ± 10.04, p = 0.002, mean difference = 1.38 [standard error: 0.42]). There was a dose response effect, with the BIS proportionately decreasing as MAP decreased below LLA (β = 0.15, 95% CI for the average slope across all patients 0.07 to 0.23, p < 0.001). In contrast, BIS was relatively unchanged when MAP was above LLA (β = 0.03, 95% CI for the average slope across all patients -0.02 to 0.09, p = 0.22). Additionally, increasing CBFV and rSO₂ were associated with increasing BIS. Patients with postoperative delirium had lower mean BIS and higher percentage of time duration with BIS <45 compared to patients without delirium.

CONCLUSIONS

There was an association of BIS and metrics of cerebral perfusion during a period of constant anesthetic administration, but the absolute magnitude of change in BIS as MAP decreased below the LLA was small.

Offline comparison of processed electroencephalogram monitors for anaesthetic-induced electroencephalogram changes in older adults

BACKGROUND

Several devices record and interpret patient brain activity via electroencephalogram (EEG) to aid physician assessment of anaesthetic effect. Few studies have compared EEG monitors on data from the same patient. Here, we describe a set-up to simultaneously compare the performance of three processed EEG monitors using pre-recorded EEG signals from older surgical patients.

METHODS

A playback system was designed to replay EEG signals into three different commercially available EEG monitors. We could then simultaneously calculate indices from the SedLine® Root (Masimo Inc., Irvine, CA, USA; patient state index [PSI]), bilateral BIS VISTA™ (Medtronic Inc., Minneapolis, MN, USA; bispectral index [BIS]), and Datex Ohmeda S/5 monitor with the Entropy™ Module (GE Healthcare, Chicago, IL, USA; E-entropy index [Entropy]). We tested the ability of each system to distinguish activity before anaesthesia administration (pre-med) and before/after loss of responsiveness (LOR), and to detect suppression incidences in EEG recorded from older surgical patients receiving beta-adrenergic blockers. We show examples of processed EEG monitor output tested on 29 EEG recordings from older surgical patients.

RESULTS

All monitors showed significantly different indices and high effect sizes between comparisons pre-med to after LOR and before/after LOR. Both PSI and BIS showed the highest percentage of deeply anaesthetised indices during periods with suppression ratios (SRs) > 25%. We observed significant negative correlations between percentage of suppression and indices for all monitors (at SR >5%).

CONCLUSIONS

All monitors distinguished EEG changes occurring before anaesthesia administration and during LOR. The PSI and BIS best detected suppressed periods. Our results suggest that the PSI and BIS monitors might be preferable for older patients with risk factors for intraoperative awareness or increased sensitivity to anaesthesia.

A prospective observational cohort pilot study of the association between midazolam use and delirium in elderly endoscopy patients

Background

Midazolam is a benzodiazepine commonly used in procedural sedation and general anaesthesia. Current anaesthetic guidelines advise the avoidance of benzodiazepines in elderly patients due to concerns of an increased risk of delirium. Delirium is associated with significant patient morbidity and mortality, while also increasing health costs. Despite this, midazolam is often used in elderly patients undergoing low risk procedures due to the benefits of rapid onset, anxiolysis and haemodynamic stability compared to other sedatives. To date, studies describing the relationship between midazolam use and delirium in elderly patients undergoing low risk procedures, such as endoscopy, are limited.

Method

This was a prospective observational cohort pilot study identifying the prevalence of delirium pre-procedure and incidence of delirium post-procedure in elderly endoscopy patients receiving midazolam. The study population was elderly patients greater than 65 years of age, without underlying cognitive dysfunction, undergoing elective endoscopy. Electronic databases were used for collection of demographic and clinical information. Delirium was identified through the administration of the Family Confusion Assessment Method survey; this was administered to carers of the study population 24–48 h pre and post procedure to categorically identify the presence or absence of delirium.

Results

Fifty-eight participants were recruited for this study and eighteen were subsequently excluded based upon additional exclusion criteria. Forty patients were included in the final results. American Society of Anaesthesiology Classification (ASA) of patients were as follows: 1 (9 patients), 2 (12 Patients), 3 (16 Patients) and 4 (3 patients). Patients underwent gastroscopy, colonoscopy or combined gastroscopy and colonoscopy. This study identified no cases of delirium in elderly patients after administration of midazolam for elective endoscopy procedures 24–48 h post-procedure. Additionally, a high proportion of elderly patients were found to have received midazolam.

Conclusion

No episodes of delirium were identified in this study. This finding runs counter to current guideline recommendations regarding midazolam use in the elderly patient and that elderly patients undergoing elective endoscopy represent a significantly different patient population compared to those previously studied. This study suggests that in the study population that the risk of delirium in patients exposed to midazolam in elective endoscopy was not demonstrated and that it may be safe to perform experimental studies to elucidate the safety of midazolam in larger studies.

Impact of delirium in acute cardiac care unit after transcatheter aortic valve replacement

BACKGROUND

Delirium is a cognitive disorder that commonly occurs during hospitalization in acute cardiac care units (ACCU), but its effect after transcatheter aortic valve replacement (TAVR) has not been well evaluated. The objective of this study is to determine the incidence, predictive factors and prognostic impact of delirium following TAVR.

METHODS

A total of 501 consecutive patients admitted to an ACCU after TAVR were included. The Confusion Assessment Method was used to evaluate delirium during ACCU stay. Risk factors, preventive pharmacological treatment, peri-procedural characteristics and complications were assessed. Clinical events were recorded with a median follow-up of 24 months.

RESULTS

The incidence of delirium after TAVR was 22.0% (n = 110). Previous cognitive impairment (OR 4.17; 95% CI 1.11-15.71; p = 0.035), peripheral arterial disease (OR 4.54; 95% CI 1.79-11.54; p = 0.001), the use of general anaesthesia (OR 2.55; 95% CI 1.32-4.90; p = 0.005), and prolonged mechanical ventilation (OR 18.86; 95% CI 1.85-192.58; p = 0.013) were significantly associated with the development of delirium. Patients with delirium had a greater hospital length of stay (7.5 [5.5-13.5] vs 5.6 [4.6-8.2] days, mean difference - 3.49; 95% CI -5.45 to -1.52; p < 0.001), and higher in-hospital (OR 2.68; 95% CI 1.02-6.99; p = 0.045), 1-year (HR 2.09; 95% CI 1.13-3.87; p = 0.018) and 2-year mortality (HR 1.94; 95% CI 1.12-3.34; p = 0.017).

CONCLUSIONS

Delirium is a frequent complication in patients admitted to ACCU after TAVR, and is associated with prolonged hospital stay and higher in-hospital and mid-term mortality.

Investigating how electroencephalogram measures associate with delirium: A systematic review

Delirium is a common neurocognitive disorder in hospital settings, characterised by fluctuating impairments in attention and arousal following an acute precipitant. Electroencephalography (EEG) is a useful method to understand delirium pathophysiology. We performed a systematic review to investigate associations between delirium and EEG measures recorded prior, during, and after delirium. A total of 1,655 articles were identified using PsycINFO, Embase and MEDLINE, 31 of which satisfied inclusion criteria. Methodological quality assessment was undertaken, resulting in a mean quality score of 4 out of a maximum of 5. Qualitative synthesis revealed EEG slowing and reduced functional connectivity discriminated between those with and without delirium (i.e. EEG during delirium); the opposite pattern was apparent in children, with cortical hyperexcitability. EEG appears to have utility in differentiating those with and without delirium, but delirium vulnerability and the long-term effects on brain function require further investigation. Findings provide empirical support for the theory that delirium is a disorder of reduced functional brain integration.

Tools Are Needed to Promote Sedation Practices for Mechanically Ventilated Patients

Suboptimal sedation practices continue to be frequent, although the updated guidelines for management of pain, agitation, and delirium in mechanically ventilated (MV) patients have been published for several years. Causes of low adherence to the recommended minimal sedation protocol are multifactorial. However, the barriers to translation of these protocols into standard care for MV patients have yet to be analyzed. In our view, it is necessary to develop fresh insights into the interaction between the patients' responses to nociceptive stimuli and individualized regulation of patients' tolerance when using analgesics and sedatives. By better understanding this interaction, development of novel tools to assess patient pain tolerance and to define and predict oversedation or delirium may promote better sedation practices in the future.

Deficiency of Mitochondrial Functions and Peroxidation of Frontoparietal Cortex Enhance Isoflurane Sensitivity in Aging Mice

Background: Hypersensitivity to general anesthetics may predict poor postoperative outcomes, especially among the older subjects. Therefore, it is essential to elucidate the mechanism underlying hypersensitivity to volatile anesthetics in the aging population. Given the fact that isoflurane sensitivity increases with aging, we hypothesized that deficiencies of mitochondrial function and elevated oxidative levels in the frontoparietal cortex may contribute to the enhanced sensitivity to isoflurane in aging mice. Methods: Isoflurane sensitivity in aging mice was determined by the concentration of isoflurane that is required for loss of righting reflex (LORR). Mitochondrial bioenergetics of the frontoparietal cortex was measured using a Seahorse XFp analyzer. Protein oxidation and lipid oxidation in the frontoparietal cortex were assessed using the Oxyblot protein oxidation detection kit and thiobarbituric acid reactive substance (TBARS) assay, respectively. Contributions of mitochondrial complex II inhibition by malonate and peroxidation by ozone to isoflurane sensitivity were tested in vivo. Besides, effects of antioxidative therapy on mitochondrial function and isoflurane sensitivity in mice were also measured. Results: The mean concentration of isoflurane that is required for LORR in aging mice (14-16 months old) was 0.83% ± 0.13% (mean ± SD, n = 80). Then, the mice were divided into three groups as sensitive group (S group, mean - SD), medium group (M group), and resistant group (R group, mean + SD) based on individual concentrations of isoflurane required for LORR. Activities of mitochondrial complex II and complex IV in mice of the S group were significantly lower than those of the R group, while frontoparietal cortical malondialdehyde (MDA) levels were higher in the mice of S group. Both inhibition of mitochondrial complexes and peroxidation significantly decreased the concentration of isoflurane that is required for LORR in vivo. After treatment with idebenone, the levels of lipid oxidation were alleviated and mitochondrial function was restored in aging mice. The concentration of isoflurane that required for LORR was also elevated after idebenone treatment. Conclusions: Decreased mitochondrial functions and higher oxidative stress levels in the frontoparietal cortex may contribute to the hypersensitivity to isoflurane in aging mice.