Should general anaesthesia be avoided in the elderly?

Melatonin and its analogues for the prevention of postoperative delirium: A systematic review and meta-analysis

It remains unclear whether melatonin and its analogues prevent postoperative delirium (POD). Therefore, we conducted a systematic review and meta-analysis to evaluate the effect of melatonin and its analogues on POD prevention. PubMed, Cochrane Library, Web of Science, Embase and CINAHL databases were searched. Primary outcome was the incidence of POD. Six randomized controlled trials, 2 cohort studies and 1 case-control study were included in this meta-analysis. Results showed that melatonin and its analogue ramelteon decreased the incidence of POD in the entire adult surgical population (odds ratio [OR] = 0.45, 95% confidence interval [CI] 0.24-0.84, P = .01). When administered at a higher dose (5 mg), melatonin was effective in reducing the POD incidence (OR = 0.32, 95% CI 0.20-0.52, P < .00001). Melatonin administered less than 5 elimination half-lives before the surgery significantly reduced the POD incidence (OR = 0.31, 95% CI 0.19-0.49, P < .00001). Current literature supports the effectiveness of melatonin and its analogue ramelteon in POD prevention. However, the present study was limited by the significant heterogeneity of the included studies. More studies are needed to ascertain the preventive effect of melatonin and its analogues on the incidence of delirium after cardiac and noncardiac surgeries.

Comparing outcomes after peripheral nerve block versus general anesthesia for lower extremity amputation: a nationwide exploratory retrospective cohort study in Japan

Background and objectives

The health benefits of peripheral nerve block (PNB) on postoperative complications after lower extremity amputation (LEA) compared with general anesthesia (GA) remains controversial. We performed a retrospective propensity score-matched cohort analysis to compare major outcomes after LEA with PNB versus GA.

Materials and methods

We used a nationwide inpatient database in Japan to compare patient outcomes after LEA with PNB versus GA from 2010 to 2016. Our primary outcome was 30-day mortality after LEA. The incidence of composite morbidity from life-threatening complications and of delirium within 30 days after LEA were secondary outcomes. We conducted propensity score-matched analyses of patients who underwent below knee or foot amputation using 36 covariates. Logistic regression analyses fitted with generalized estimating equations were performed to calculate ORs and their 95% CIs.

Results

Of 11 796 patients, 747 received PNB and 11 049 received GA. After one-to-four propensity score matching, 747 patients were included in the PNB group and 2988 in the GA group. The adjusted ORs for postoperative mortality, composite morbidity and delirium within 30 days after LEA were 1.11 (95% CI 0.75 to 1.64), 1.15 (95% CI 0.85 t o1.56) and 0.75 (95% CI 0.57 to 0.98), respectively, for the PNB group with reference to the GA group.

Conclusions

There was no significant difference between groups in 30-day mortality or composite morbidity. The PNB group showed a significantly lower risk of postoperative delirium than the GA group. Our findings suggest that PNB may have advantages over GA in preventing postoperative delirium among patients undergoing LEA.

Intranasal dexmedetomidine in elderly subjects with or without beta blockade: a randomised double-blind single-ascending-dose cohort study

BACKGROUND

The aim of this double-blind, placebo-controlled, single-ascending-dose study was to determine the safety and tolerability of intranasal dexmedetomidine in the elderly.

METHODS

We randomly assigned 48 surgical patients ≥65 yr of age to receive single intranasal doses of dexmedetomidine or placebo (5:1 ratio) in four sequential dose cohorts: 0.5, 1.0, 1.5, and 2.0 μg kg-1. Each dose cohort comprised two groups of six subjects: a group of subjects using β-blockers and a group not taking β-blockers. Vital signs and sedation depth (Modified Observer's Assessment of Alertness and Sedation [MOAA/S] and bispectral index) were measured for 2 h after administration. Blood samples were taken to determine dexmedetomidine plasma concentrations.

RESULTS

One subject (1.0 μg kg-1) had acute hypotension requiring ephedrine. Systolic arterial BP decreased >30% in 15 of 40 subjects (37.5%) receiving dexmedetomidine, lasting longer than 5 min in 11 subjects (27.5%). The MAP decreased >30% (>5 min) in 10%, 20%, 50%, and 30% of subjects receiving dexmedetomidine 0.5, 1.0, 1.5, and 2.0 μg kg-1, respectively, irrespective of β-blocker use. HR decreased 10-26%. MOAA/S score ≤3 occurred in 18 (45%) subjects; eight (20%) subjects receiving dexmedetomidine showed no signs of sedation. Tmax was 70 min. Cmax was between 0.15 ng ml-1 (0.5 μg kg-1) and 0.46 ng ml-1 (2.0 μg kg-1).

CONCLUSIONS

Intranasal dexmedetomidine in elderly subjects had a sedative effect, but caused a high incidence of profound and sustained hypotension irrespective of β-blocker use. The technique is unsuitable for routine clinical use.

CLINICAL TRIAL REGISTRATION

NTR5513 (The Netherlands Trial Registry 5513).

A two-step surgery and a multidisciplinary approach in a centenarian patient with an acute presentation of right colon cancer

Background

As surgery remains the cornerstone of colorectal cancer (CRC) treatment, the number of older patients presented for colorectal resection is rapidly increasing. Nevertheless, the choice to operate an oldest-old patient still remain challenging and requires a careful assessment of risk to benefit ratio in order to guarantee appropriate surgical strategies and perioperative management.

Case presentation

A centenarian patient, acutely admitted to the emergency department, was diagnosed with an ileus caused by stenosing ascending colon cancer with abnormal distension of the right colon at high risk of perforation. Facing with this complex clinical scenario, a lateral decompressive cecostomy as alternative surgical procedure, was performed in local anesthesia in order to avoid the stressful event of an emergency surgery. Thereafter, the patient was admitted to the surgical ward and followed by a geriatrician who performed a comprehensive geriatric assessment (CGA) and daily clinical evaluations. This integrated plan of care was mainly focused on rehabilitation, nutritional interventions and therapeutic reconciliation, maximizing patient’s clinical conditions and performance status. Then, the second surgical step, the radical colon surgery with curative intent and bowel continuity reestablishment was performed, demonstrating to be feasible and safety also in a very advanced age patient in term of prolonged survival and preservation of an adequate quality of life.

Conclusions

This is the first case-report that illustrates a successful two step surgery for CRC in a centenarian patient thanks to a multidisciplinary based approach, overwhelming the mere concept of chronological age.

Conscious sedation service for geriatric and special-care dentistry: A health policy brief

Background:

Geriatric and special care dentistry (GSD) involves oral health care for seniors and individuals with disabilities. Due to ethical issues, finances, waiting times, treatment versatility and so on, conscious sedation (CS) may have a place to optimise the delivery of care.

Objectives:

This article identifies considerations for implementing CS in GSD services in Singapore.

Methods:

Taking the form of a health policy brief, this review (a) defines the situation for patients with special-care needs and justified the need for dental CS, (b) makes reference to practices from countries with established dental CS services, (c) states and evaluates available CS techniques for the GSD centre in Singapore and (d) discusses action plans and considerations for implementation.

Results:

Demographic analysis revealed that 23.8% of the GSD patients could have benefitted from CS, or 44.7% of all patients who required behavioural management. The key advantages of CS included enhanced safety, more teeth saved and a reduction in general anaesthesia wait, amongst others. Conventional dental CS techniques included midazolam via various routes, nitrous oxide and ketamine. To establish a CS service, key points of consideration need to be conceptualised first, such as adequate training, perception of patients and providers, operational costs, facilities and developing guidance specific for oral health professionals.

Conclusion:

A local CS service will be beneficial for GSD patients in view of the challenges faced. A group of experts and stakeholders is needed to provide practical consensus.

Translation and cultural adaptation of the Greek version of the confusion assessment method diagnostic algorithm and the nursing delirium screening scale and their inter-rater reliability: A prospective cohort study

AIM

The lack of standardized tools limits the diagnosis οf postoperative delirium (POD) in the Greek population. Our aim was the translation and the cultural adaptation of the confusion assessment method (CAM) diagnostic algorithm and the nursing delirium screening scale (nu-DESC) in the Greek surgical population, and the determination of their inter-rater reliability.

METHODS

After Ethical approval and registration as a clinical trial (NCT04154176), a prospective cohort study was conducted in the Department of Anesthesiology, University Hospital of Larissa, Greece. Patients at least 60 years old, undergoing elective non-cardiac surgery, under general anesthesia were included.

RESULTS

Data from 60 patients, 180 records in total, were analyzed. There was an "almost perfect agreement" between the raters with the use of CAM (Cohen's Kappa estimate: 0.960; 95 % CI: 0.905-1.000) and nu-DESC (Cohen's Kappa estimate: 0.981; 95 % CI: 0.944-1.000). The agreement on each specific question of CAM and nu-DESC ranged from "substantial" to "almost perfect agreement". Based on the CAM, the sensitivity and specificity of nu-DESC were 0.97 (95 % CI: 0.82-1.00) and 0.99 (95 % CI: 0.96-1.00), respectively. The Greek versions of CAM and nu-DESC showed a high inter-rater agreement.

CONCLUSION

With the translation, the cultural adaptation, and the determination of their inter-rater agreement, the CAM diagnostic algorithm and the nu-DESC may serve as reliable instruments for the detection of POD in the Greek population. HIPPOKRATIA 2020, 24(1): 8-14.

Comparison of Effects of PELD and Fenestration in the Treatment of Geriatric Lumbar Lateral Recess Stenosis

Purpose

Although degenerative lumbar spinal stenosis (LSS) is increasingly being diagnosed in older people, there is much uncertainty about the appropriate operative treatment options. The objective of this study was to compare the outcome of percutaneous endoscopic lumbar decompression (PELD) versus fenestration for lumbar lateral recess stenosis (LRS) in geriatric patients over 75 years old.

Materials and methods

This prospective controlled study was performed on 46 consecutive over aged patients with lateral recess stenosis who underwent either PELD or fenestration. Clinical data were recorded before, 1 week, 3 months and 1.5 years after surgery using visual analog scale (VAS), Japanese Orthopaedic Association Score (JOA), The Short-Form-36 (SF-36), and the modified Macnab evaluation criteria.

Results

The patients’ mean age was 82.7 years (aged 75–93 years) in PELD group and 79.1 years (aged 75–88 years) in fenestration group. No statistical difference was found between PELD group and fenestration group with regards to VAS-back pain, VAS-leg pain, JOA and at 3 months and 1.5-year follow-up. However, the PELD group had a lower mean VAS for back pain at 1 week postoperatively (P<0.05). The quality of life in PELD group achieved the same remarkable improvement as fenestration group (P>0.05). Operative time (min) was similar between two groups (p>0.05), while the PELD techniques brought advantages in blood loss (mL) (48.3 vs 128.2, p<0.05), early ambulation (h) (5.5 vs 25.2, p<0.05), and anesthesia-related complications.

Conclusion

Both PELD and fenestration showed favorable clinical outcomes for the treatment of lumbar lateral recess stenosis. In addition, PELD had advantages such as reduced traumatization and less anesthesia-related complications. In terms of quality of life and complications after operation, PELD under local anesthesia could be an efficient supplement to conventional decompression surgery in geriatric patients with lumbar lateral recess stenosis.

Evaluation of Ultrasound-guided Genitofemoral Nerve Block Combined with Ilioinguinal/iliohypogastric Nerve Block during Inguinal Hernia Repair in the Elderly

To evaluate the anesthetic effect of ultrasound-guided (USG) ilioinguinal/iliohypogastric nerve (II/IHN) block combined with genital branch of genitofemoral nerve (GFN) block in the elderly undergoing inguinal hernia repair, 54 old patients (aged 60-96years, ASA I-III) with indirect hernia were enrolled and scheduled for unilateral tension-free herniorrhaphy. Patients were grouped randomly to receive either USG II/IHN plus GFN block (Group G) or USG II/IHN block alone (Group I). The intraoperative visual analogue scale (VAS) scores were recorded at skin incision, at spermatic cord/round ligament traction and at sac ligation. The resting and dynamic VAS scores were recorded postoperatively. The requirements of extra sedatives and analgesics for intra- and postoperative analgesia were assessed. Occurrence of complications of the block, postoperative nausea and vomiting and femoral nerve palsy was also reported. Both groups showed similar sensory block. When stretching spermatic cord/round ligament, the patients in group G had significantly lower VAS scores than in group I. And group G used much fewer adjuvant sedatives and analgesics to achieve adequate anaesthesia. In addition, group G was presented with better intraoperative anaesthesia and lower postoperative dynamic VAS scores at all time points tested. No significant difference was found in the postoperative requirement of rescue medication. Both groups showed no complications related to the block and group G reported no femoral nerve palsy. The addition of GFN block to II/IHN block improves the quality of perioperative anesthesia and analgesia in the elderly and reduces the consumption of extra sedatives and analgesics during the surgery.

Association of Changes in Plasma Neurofilament Light and Tau Levels With Anesthesia and Surgery: Results From the CAPACITY and ARCADIAN Studies

Importance

Anesthesia and surgery are believed to act on the central nervous system by a fully reversible mechanism innocuous to nerve cells. Evidence that neurological sequelae may follow would challenge this belief and would thereby suggest a need to reassess theories of the mechanism of anesthetic action or the response of the central nervous system to surgery.

Objective

To measure 2 biomarkers of neurological injury (neurofilament light and tau) in plasma in a series of timed collections before and after anesthesia and surgery.

Design, Setting, and Participants

These 2 related observational studies (CAPACITY and ARCADIAN) recruited patients 60 years and older who were undergoing general anesthesia for surgeries performed within a tertiary hospital. Blood samples were taken immediately before surgical anesthesia was administered and then sequentially after surgery at 30-minute, 6-hour, 24-hour, and 48-hour intervals. Sampling took place from January 2014 to August 2015. Data analysis took place from October 2016 to February 2017.

Main Outcomes and Measures

Plasma neurofilament light and tau.

Results

A total of 30 patients were enrolled (13 from the CAPACITY study and 17 from the ARCADIAN study). The mean (SD) age was 69.1 (7.0) years, and 18 members (59%) of the participant group were female; 22 (73%) were undergoing joint arthroplasty. Mean neurofilament light increased at each measurement from a combined baseline mean (SD) of 22.3 (20.4) pg/mL to a maximal combined mean (SD) level of 35.1 (28.7) pg/mL, a maximum increase of 67% (95% CI, 45%-89%; P < .001), at 48 hours postoperatively. The level of tau increased significantly from baseline at every measurement, from a combined baseline mean (SD) of 3.1 (1.3) pg/mL to a maximal combined mean (SD) of 10.8 (9.5) pg/mL, a peak increase of 257% (95% CI, 154%-361%; P < .001), at 6 hours postoperatively. After 6 hours, the mean level began to return to baseline but remained elevated after 48 hours.

Conclusions and Relevance

Neurofilament light is a specific marker of axonal injury and has been shown to indicate neuronal damage in a number of diseases. Tau proteins are an integral component of axonal integrity, and increased tau indicates neuronal damage. The increases in both neurofilament light and tau over 48 hours after surgery suggest that general anesthesia and surgery may be associated with neuronal damage in the short term. Further investigations will be required to study any association with clinical outcomes. These preliminary findings demand that we question the prevailing assumption that anesthesia and surgery are innocuous, transient, and without injurious changes to the central nervous system.

Anesthetics: from modes of action to unconsciousness and neurotoxicity

Modern anesthetic compounds and advanced monitoring tools have revolutionized the field of medicine, allowing for complex surgical procedures to occur safely and effectively. Faster induction times and quicker recovery periods of current anesthetic agents have also helped reduce health care costs significantly. Moreover, extensive research has allowed for a better understanding of anesthetic modes of action, thus facilitating the development of more effective and safer compounds. Notwithstanding the realization that anesthetics are a prerequisite to all surgical procedures, evidence is emerging to support the notion that exposure of the developing brain to certain anesthetics may impact future brain development and function. Whereas the data in support of this postulate from human studies is equivocal, the vast majority of animal research strongly suggests that anesthetics are indeed cytotoxic at multiple brain structure and function levels. In this review, we first highlight various modes of anesthetic action and then debate the evidence of harm from both basic science and clinical studies perspectives. We present evidence from animal and human studies vis-à-vis the possible detrimental effects of anesthetic agents on both the young developing and the elderly aging brain while discussing potential ways to mitigate these effects. We hope that this review will, on the one hand, invoke debate vis-à-vis the evidence of anesthetic harm in young children and the elderly, and on the other hand, incentivize the search for better and less toxic anesthetic compounds.

Association of Anesthetic Exposure Time With Clinical Outcomes After Endovascular Therapy for Acute Ischemic Stroke

Background: The optimal sedative regimen with general anesthesia (GA) or conscious sedation for patients undergoing endovascular therapy (EVT) remains controversial. Apart from sedative regimen, the duration of anesthetic exposure may affect clinical outcomes. We aimed to determine whether there is an association between anesthetic exposure time and clinical outcomes in mechanically ventilated stroke patients undergoing EVT for large vessel occlusion.

Methods: This was an observational study of consecutive ischemic stroke patients who underwent EVT for anterior circulation large vessel occlusion under GA from January 2016 to March 2018. To minimize confounding by indication, we restricted our analysis to patients whose anesthetic exposure lasted <72 h. Multivariable logistic regression modeling adjusted for covariates was employed to evaluate whether 90-days independent functional outcome (defined as modified Rankin Scale scores 0–2) and 90-days survival could be predicted by anesthetic exposure time.

Results: During the study period, 138 patients with ischemic stroke who underwent EVT received GA and fulfilled our study criteria: median age was 77 years (interquartile range, 65–82); 46.4% were men; median NIHSS score was 18 (15–21), median ASPECT score was 7 (6–8). Median duration of GA was 5.4 (2.5–19.7) h. Logistic regression modeling revealed an independent association between duration of anesthetic exposure and both 90-days independent functional outcome (p = 0.034) and 90-days survival (p = 0.011). Each additional 15-min of anesthetic exposure decreased the likelihood of achieving an independent functional outcome at 90 days by 1.5% and of being alive at 90 days by 1.0%.

Conclusion: Our data promotes the notion that ischemic stroke patients who require peri-interventional GA for EVT should be extubated as soon as possible after the procedure.

Effects of different analgesia regimens on early post-operative cognitive dysfunction in elderly patients undergoing radical resection of cervical carcinoma

This study was designed to compare the effects of epidural and intravenous analgesia on early post-operative cognitive dysfunction (POCD) in elderly patients undergoing radical resection of cervical cancer. For this purpose, 74 patients aged 60-78 years [body mass index (BMI), 18-25 kg/m²; American Society of Anesthesiologists (ASA) classification score of I-III) undergoing radical resection of cervical cancer were divided into the epidural group (group E) and parenteral group (group P) groups (37 patients in each group). All patients underwent their surgical procedures under epidural anesthesia and intravenously-delivered general anesthesia. Patient-controlled analgesia (PCA) was supplied for 72 h after the surgery. Epidural analgesia was provided for the patients in group E and intravenous analgesia was provide for those in group P. General patient information was recorded and peripheral blood neutrophil counts, C-reactive protein (CRP) levels and interleukin (IL)-6 concentrations were measured immediately prior to the surgery (T₀), and at 24, 48 and 72 h after the procedure (T₁, T₂ and T₃, respectively). Visual analog scale (VAS) scores were also recorded at T₁, T₂ and T₃, and the mini-mental state evaluation (MMSE) scores at T₀, T₁, T₂, and T₃ were calculated. Patients were diagnosed as having POCD according to their MMSE score differences between the peri-operative and post-operative values. The results revealed that the levels of CRP and IL-6 significantly increased in both groups after the surgery (T_1-3). However, the CRP and IL-6 levels in group E were significantly lower than those in group P at all time points examined (P<0.05). The VAS scores in group E at T₁, T₂ and T₃ were significantly lower than those in group P (P<0.05). Finally, the incidence of POCD in group E was significantly lower than that in group P (P<0.05). On the whole, the post-operative epidural analgesia reduced the systemic inflammatory response, the perceived pain, and the incidence of POCD in patients undergoing radical resection of cervical cancer, when compared with the effects of intravenous analgesia.

Local Anesthetic Flexible Ureterorenoscopy in the Management of Urolithiasis

Introduction: Patients unfit for general anesthesia who present with renal tract pathology currently have limited options. Many of these patients present in the emergency setting with imperative reasons for intervention, including sepsis, renal failure, and pain. Conservative management and temporizing measures, such as percutaneous nephrostomy, are associated with significant morbidity. Ureterorenoscopy (URS) is a central component of the management of upper tract disease and is routinely performed under general anesthesia. We describe our institution's experience of URS using only local anesthetic (LA) lubricating gel per urethra. Methods: A single centre, retrospective analysis of 78 patients was performed for an 11 year period. Demographic data and Charlson comorbidity index scoring were collected for all patients. Outcomes, including stone-free rates, tolerability, and complications, were analyzed. Results: In total 58% of patients were men. Mean age was 68 and Charlson comorbidity index was 5.2. Indications for URS included pain (68%) and renal failure (15%). Totally 10% of patients previously had retrograde stenting because of sepsis. Median stone size was 8 mm. All patients were able to tolerate the procedure and none were abandoned because of pain. The overall stone-free rate was 82% after one procedure. The stone-free rate for mid and distal ureteral stones was 97%. Nineteen percent of patients were left with a ureteral stent after the procedure, with the remaining patients left totally tubeless. Median length of stay was 1 day. There were no complications above Clavien Grade 2. Conclusion: Urologists are increasingly faced with unfit patients presenting with urolithiasis. In the appropriately selected patient, LA flexible ureterorenoscopy is a feasible option with good outcomes. This approach is a useful addition to the armamentarium available to patients deemed unsuitable for general or regional anesthesia.

Surgical approach and geriatric evaluation for elderly patients with colorectal cancer

This review aims to define the most appropriate surgical approach and geriatric evaluation for elderly patients with colorectal cancer (CRC). Surgery represents the main treatment for CRC, but elderly cancer patients still represent a challenge for the surgeon due to frequent comorbidities such as cardiovascular and pulmonary diseases, which increase operative risk as well as the risk of postoperative morbidity and mortality. Cancer patients with comorbidities show lower survival rates and quality of life, together with higher healthcare costs. There is also evidence that patients with comorbidities sometimes receive modified treatment, compromising optimal care. To optimize treatment, the approach to elderly cancer patients needs a multidisciplinary team to assess preoperative conditions, prevent post-surgical complications and improve outcome, especially for frail patients. Laparoscopic surgery for CRC shows a number of advantages compared to conventional surgery such as less postoperative pain, rapid return to prior activities and a decrease in costs. Recent studies confirm that laparoscopic procedures could be performed safely on both older and younger patients with no difference compared with open surgery as regards morbidity or length of hospital stay.

The influence of anesthetic techniques on postoperative cognitive function in elderly patients undergoing hip fracture surgery: General vs spinal anesthesia

BACKGROUND

Hip fracture is common and morbid in elderly patients. Postoperative cognitive dysfunction (POCD) is also very common in these subjects undergoing surgery with an incidence which exceeds 40% in some reports. To date, the evidence is ambiguous as to whether anesthetic technique may affect the patients' outcome as far as postoperative cognitive function is concerned.

OBJECTIVE

The aim of this study was to compare the effect of general and subarachnoid (spinal) anesthesia on the development of POCD up to 30 days after surgery in elderly patients undergoing hip fracture surgery. Methods Subjects over 65 years with hip fracture undergoing surgery were recruited for this study. They were enrolled and randomized to receive either general anesthesia (GA group) or subarachnoid (spinal) anesthesia (S group). Cognitive function was assessed using a battery of neuropsychological tests undertaken preoperatively and at 30 days postoperatively. The incidence of delirium was examined during the same period and their functional status, in terms of activities of daily living was also recorded.

RESULTS

A total of seventy patients, 33 men and 37 females, mean age of 76 years were analyzed. Thirty-three patients received general anesthesia (GA group) and 37 subarachnoid (spinal) anesthesia (S group). The two groups of patients were similar with respect to baseline characteristics, comorbidities and perioperative data. The results of neuropsychological testing showed that there were no significant differences between the groups in eight out of ten neurocognitive tests at baseline and 30 days after surgery. There was a statistically significant decline of the Instrumental Activities of Daily Living Scale score in S group compared with group GA on the 30th postoperative day (p = 0.043). A significant decline was also present in Color-Word Task test in S group compared with group GA at baseline (p = 0.014) and 30 days postoperatively (p = 0.003). Postoperative delirium was present in four patients (12%) for the GA group, and in 10 patients (27%) for the group receiving subarachnoid anesthesia.

CONCLUSION

We concluded that the choice of anesthesia modality does not appear to influence the emergence of postoperative cognitive dysfunction in elderly patients undergoing hip fracture surgery.

Preoperative Management of the Geriatric Patient: Frailty and Cognitive Impairment Assessment

As the population ages, more geriatric patients will be presenting for surgical procedures. Preoperative evaluation seeks to assess patients for geriatric syndromes: frailty, sarcopenia, functional dependence, and malnutrition. Age-related changes in physiology increase risk for central nervous system, cardiovascular, pulmonary, renal, hepatic, and endocrine morbidity and mortality. Identification of various comorbidities allows for preoperative optimization and for opportunities for intervention including nutritional supplementation and prehabilitation, which may improve postoperative outcomes.

Postoperative cognitive disorders: an update

BACKGROUND

Cognitive dysfunction is a common complication after surgery. It is a major cause for increased, sometimes long-term, morbidity and mortality.

METHODS

In this narrative review we performed a literature search regarding postoperative cognitive decline regarding risk factors, the type of surgical intervention, potential neuroprotective effects of anesthetic drugs, and associated quality of life and healthcare costs.

RESULTS

Several risk factors are implicated in postoperative cognitive impairment. Cardiac surgery and specific orthopedic interventions are associated with a higher incidence of postoperative cognitive disorders. Results regarding the neuroprotective effects of anesthetics agents are still controversial but promising. Postoperative cognitive alterations are a major public healthcare issue as they impair the everyday quality of life, and expand the yearlong expenses.

CONCLUSIONS

Postoperative cognitive disorders are devastating, potentially life-threatening complications. High-suspicion, especially in high-risk patients and operations, and adoption of available neuroprotective strategies may prove lifesaving. HIPPOKRATIA 2018, 22(4): 147-154.

Do Complexity Measures of Frontal EEG Distinguish Loss of Consciousness in Geriatric Patients Under Anesthesia?

While geriatric patients have a high likelihood of requiring anesthesia, they carry an increased risk for adverse cognitive outcomes from its use. Previous work suggests this could be mitigated by better intraoperative monitoring using indexes defined by several processed electroencephalogram (EEG) measures. Unfortunately, inconsistencies between patients and anesthetic agents in current analysis techniques have limited the adoption of EEG as standard of care. In attempts to identify new analyses that discriminate clinically-relevant anesthesia timepoints, we tested 1/f frequency scaling as well as measures of complexity from nonlinear dynamics. Specifically, we tested whether analyses that characterize time-delayed embeddings, correlation dimension (CD), phase-space geometric analysis, and multiscale entropy (MSE) capture loss-of-consciousness changes in EEG activity. We performed these analyses on EEG activity collected from a traditionally hard-to-monitor patient population: geriatric patients on beta-adrenergic blockade who were anesthetized using a combination of fentanyl and propofol. We compared these analyses to traditional frequency-derived measures to test how well they discriminated EEG states before and after loss of response to verbal stimuli. We found spectral changes similar to those reported previously during loss of response. We also found significant changes in 1/f frequency scaling. Additionally, we found that our phase-space geometric characterization of time-delayed embeddings showed significant differences before and after loss of response, as did measures of MSE. Our results suggest that our new spectral and complexity measures are capable of capturing subtle differences in EEG activity with anesthesia administration-differences which future work may reveal to improve geriatric patient monitoring.

Does Adding Lidocaine to Intrathecal Bupivacaine Affect Hemodynamic Parameters during Hip Fracture Surgery?

BACKGROUND

Hip fracture is one of the most common problems in elderly that needs surgical repair. As, the majority of these patients have chronic diseases, they are at increased risk of peri-operative mortality and morbidity. The purpose of this study was to evaluate spinal anesthesia with bupivacaine vs bupivacaine in combination with lidocaine in terms of hemodynamic changes in patients undergoing hip fracture surgery.

METHODS

This double-blind clinical trial was conducted on 292 patients undergoing surgery for hip fracture under spinal anesthesia. Patients were allocated into two groups of B (10 mg of hyperbaric 0.5% Bupivacaine) and BL (5 mg hyperbaric Bupivacaine 0.5% plus 50 mg Lidocaine 5%). Sensory and motor block and hemodynamic changes were consecutively measured before spinal anesthesia (T0), immediately after spinal injection (T1), every 5 minutes for half an hour (T2- T7), and at 45 minutes (T8) and 60 minutes (T9) after injection.

RESULTS

Patients in the two groups were homogeneous in demographic characteristics including age, sex, BMI, ASA Class, baseline blood pressure and heart rate. The onsets of sensory and motor blocks in group BL were faster than group B (P=0.0001). Also, the durations of sensory and motor blocks in group B were significantly longer than group BL (P=0.0001). The BL group had a significantly lower systolic blood pressure in all periods (P<0.05). Although the heart rate in the BL group was lower than group B at all time points, this difference was only significant during T2-T3 (P=0.033 and P=0.0001, respectively). Group BL had significantly more episodes of hypotension, bradycardia, nausea and vomiting (P=0.0001, P=0.023, P=0.003, and P=0.033, respectively).

CONCLUSION

According to our findings, using Lidocaine 50 mg in combination with Bupivacaine 5 mg, compared with Bupivacaine 10 mg alone for spinal anesthesia in hip fracture fixation surgeries was associated with more hypotension and bradycardia. As a result, combination of Bupivacaine with Lidocaine at this dose is not recommended for induction of anesthesia in these patients.

A systematic review of gallstone sigmoid ileus management

INTRODUCTION

Gallstone sigmoid ileus is a rare although serious complication of cholelithiasis resulting in large bowel obstruction. The condition accounts for 4% of all gallstone ileus patients. There are no recognized management guidelines currently. Management strategies range from minimally invasive endoscopy and lithotripsy to substantial surgery. We aim to identify trends when managing patients with gallstone sigmoid ileus to help improve outcomes.

METHODS

Literature searches of EMBASE, Medline and by hand were conducted. All English language papers published from 2000 to 2017(Oct) were included. The terms 'gallstone', 'sigmoid', 'colon', 'ileus', 'coleus' and 'large bowel obstruction' were used.

RESULTS

38 papers included, male:female ratio was 8:30. Average age was 81.11 (SD ± 7.59). Average length of preceding symptoms was 5.31days (+/-SD3.16). 20/38 (59%) had diverticulosis. 89% of patients had significant comorbidities documented. 34/38 patients underwent computerized tomography. 31 stones were located within sigmoid colon, 4 at rectosigmoid junction and 2 within descending colon. Average impacted gallstone size was 4.14 cm (2.3-7 cm range). 23/38 (61%) patients' initial management was conservative or with endoscopy ± lithotripsy. Conservative management successfully treated 26% of patients. 28/38 (74%) patients ultimately underwent surgical intervention. 5/38 patients died post-operatively. Patients treated non-operatively had shorter hospital stays (4:12.3days) although not significant (p-value = 0.0056).

CONCLUSIONS

There is no management consensus from the literature. Current evidence highlights endoscopy and lithotripsy as practical firstline strategies. However, surgical intervention should not be delayed if non-operative measures fail or in emergency. Given the complexity of such patients, less invasive timesaving surgery appears practical, avoiding bowel resection and associated complications.

Postoperative Delirium in Severely Burned Patients Undergoing Early Escharotomy: Incidence, Risk Factors, and Outcomes

The aim of this study is to investigate the incidence, related risk factors, and outcomes of postoperative delirium (POD) in severely burned patients undergoing early escharotomy. This study included 385 severely burned patients (injured <1 week; TBSA, 31-50% or 11-20%; American Society of Anesthesiologists physical status, II-IV) aged 18 to 65 years, who underwent early escharotomy between October 2014 and December 2015, and were selected by cluster sampling. The authors excluded patients with preoperative delirium or diagnosed dementia, depression, or cognitive dysfunction. Preoperative, perioperative, intraoperative, and postoperative information, such as demographic characteristics, vital signs, and health history were collected. The Confusion Assessment Method was used once daily for 5 days after surgery to identify POD. Stepwise binary logistic regression analysis was used to identify the risk factors for POD, t-tests, and χ tests were performed to compare the outcomes of patients with and without the condition. Fifty-six (14.55%) of the patients in the sample were diagnosed with POD. Stepwise binary logistic regression showed that the significant risk factors for POD in severely burned patients undergoing early escharotomy were advanced age (>50 years old), a history of alcohol consumption (>3/week), high American Society of Anesthesiologists classification (III or IV), time between injury and surgery (>2 days), number of previous escharotomies (>2), combined intravenous and inhalation anesthesia, no bispectral index applied, long duration surgery (>180 min), and intraoperative hypotension (mean arterial pressure < 55 mm Hg). On the basis of the different odds ratios, the authors established a weighted model. When the score of a patient's weighted odds ratios is more than 6, the incidence of POD increased significantly (P < .05). When the score of a patient's weighted odds ratios is more than 6, the incidence of POD increased significantly (P < .05). Further, POD was associated with more postoperative complications, including hepatic and renal function impairment and hypernatremia, as well as prolonged hospitalization, increased medical costs, and higher mortality.

Screening of Potential Genes and Transcription Factors of Postoperative Cognitive Dysfunction via Bioinformatics Methods

Background

The aim of this study was to explore the potential genes and transcription factors involved in postoperative cognitive dysfunction (POCD) via bioinformatics analysis.

Material/Methods

GSE95070 miRNA expression profiles were downloaded from Gene Expression Omnibus database, which included five hippocampal tissues from POCD mice and controls. Moreover, the differentially expressed miRNAs (DEMs) between the two groups were identified. In addition, the target genes of DEMs were predicted using Targetscan 7.1, followed by protein-protein interaction (PPI) network construction, functional enrichment analysis, pathway analysis, and prediction of transcription factors (TFs) targeting the potential targets.

Results

A total of eight DEMs were obtained, and 823 target genes were predicted, including 170 POCD-associated genes. Furthermore, potential key genes in the network were remarkably enriched in focal adhesion, protein digestion and absorption, ECM-receptor interaction, and Wnt and MAPK signaling pathways.

Conclusions

Most potential target genes were involved in the regulation of TFs, including LEF1, SP1, and AP4, which may exert strong impact on the development of POCD.

Effect of sugammadex versus neostigmine/atropine combination on postoperative cognitive dysfunction after elective surgery

This study aimed to assess the effects of sugammadex and neostigmine/atropine on postoperative cognitive dysfunction (POCD) in adult patients after elective surgery. A randomised, double-blind controlled trial was carried out on 160 American Society of Anesthesiologists physical status I to III patients who were >40 years. The Mini-Mental State Evaluation, clock-drawing test and the Isaacs Set test were used to assess cognitive function at three timepoints: 1) preoperatively, 2) one hour postoperatively, and 3) at discharge. The anaesthetic protocol was the same for all patients, except for the neuromuscular block reversal, which was administered by random allocation using either sugammadex or neostigmine/atropine after the reappearance of T2 in the train-of-four sequence. POCD was defined as a decline ≥1 standard deviation in ≥2 cognitive tests. The incidence of POCD was similar in both groups at one hour postoperatively and at discharge (28% and 10%, in the neostigmine group, 23% and 5.4% in the sugammadex group, P=0.55 and 0.27 respectively). In relation to individual tests, a significant decline of clock-drawing test in the neostigmine group was observed at one hour postoperatively and at discharge. For the Isaacs Set test, a greater decline was found in the sugammadex group. These findings suggest that there are no clinically important differences in the incidence of POCD after neostigmine or sugammadex administration.

Cochlear Implant Surgery in the Elderly: The Feasibility of a Modified Suprameatal Approach Under Local Anesthesia

OBJECTIVE

Although cochlear implantation is a relatively safe procedure, there is some reticence to subject elderly people, especially those with significant comorbidity, to the risks of general anesthesia. The purpose of the study was to explore the feasibility of cochlear implant surgery under local anesthesia and sedation in elderly people.

STUDY DESIGN

Case report study (Clinical Capsule Report).

SETTING

Single tertiary academic referral center.

PATIENTS

Seven elderly subjects with severe or severe-to-profound sensorineural hearing impairment underwent cochlear implantation under local anesthesia and sedation. All subjects had significant comorbidities with an American Society of Anesthesiologists (ASA) classification 3 to 4 and explicitly expressed their concerns regarding general anesthesia. The subjects were implanted with 24 mm straight electrode array devices via a modified suprameatal approach.

INTERVENTIONS

Therapeutic.

MAIN OUTCOME MEASURE

The evaluation of a modified suprameatal approach for cochlear implant surgery under local anesthesia and sedation with respect to patient safety and compliance.

RESULTS

Cochlear implantation under local anesthesia and sedation was successful and well tolerated in all subjects. No intra- or postoperative complications occurred. Recovery was quick and all subjects were discharged on the first postoperative day. All subjects would opt again for the procedure under local anesthesia.

CONCLUSION

Cochlear implantation under local anesthesia and sedation was found to be feasible. The modified suprameatal approach lends itself for procedures under local anesthesia, because only minimal drilling is required. The application of this technique provides a safe alternative especially for the elderly with significant comorbidity and increased risks for general anesthesia.

A Novel Stress-Diathesis Model to Predict Risk of Post-operative Delirium: Implications for Intra-operative Management

Introduction: Risk assessment for post-operative delirium (POD) is poorly developed. Improved metrics could greatly facilitate peri-operative care as costs associated with POD are staggering. In this preliminary study, we develop a novel stress-diathesis model based on comprehensive pre-operative psychiatric and neuropsychological testing, a blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) carbon dioxide (CO₂) stress test, and high fidelity measures of intra-operative parameters that may interact facilitating POD. Methods: The study was approved by the ethics board at the University of Manitoba and registered at clinicaltrials.gov as NCT02126215. Twelve patients were studied. Pre-operative psychiatric symptom measures and neuropsychological testing preceded MRI featuring a BOLD MRI CO₂ stress test whereby BOLD scans were conducted while exposing participants to a rigorously controlled CO₂ stimulus. During surgery the patient had hemodynamics and end-tidal gases downloaded at 0.5 hz. Post-operatively, the presence of POD and POD severity was comprehensively assessed using the Confusion Assessment Measure -Severity (CAM-S) scoring instrument on days 0 (surgery) through post-operative day 5, and patients were followed up at least 1 month post-operatively. Results: Six of 12 patients had no evidence of POD (non-POD). Three patients had POD and 3 had clinically significant confusional states (referred as subthreshold POD; ST-POD) (score ≥ 5/19 on the CAM-S). Average severity for delirium was 1.3 in the non-POD group, 3.2 in ST-POD, and 6.1 in POD (F-statistic = 15.4, p < 0.001). Depressive symptoms, and cognitive measures of semantic fluency and executive functioning/processing speed were significantly associated with POD. Second level analysis revealed an increased inverse BOLD responsiveness to CO₂ pre-operatively in ST-POD and marked increase in the POD groups when compared to the non-POD group. An association was also noted for the patient population to manifest leucoaraiosis as assessed with advanced neuroimaging techniques. Results provide preliminary support for the interacting of diatheses (vulnerabilities) and intra-operative stressors on the POD phenotype. Conclusions: The stress-diathesis model has the potential to aid in risk assessment for POD. Based on these initial findings, we make some recommendations for intra-operative management for patients at risk of POD.

The quality of life of patients developed delirium after coronary artery bypass grafting is determined by cognitive function after discharge: A cross-sectional study

AIMS

Postoperative delirium (POD) and declined cognitive function were common in patients (especially elderly patients) who underwent coronary artery bypass grafting (CABG), which may affect quality of life (QoL). The aim of this study was to determine the relationships among age, POD, declined cognitive function, and QoL in patients who underwent CABG.

METHODS

Consecutive patients who underwent first time elective CABG and assessed for POD using Confusion Assessment Method for intensive care unit for 5 postoperative days from November 2013 to March 2015 were recruited. A cross-sectional study was conducted during April 2015 to assess their cognitive function and QoL, using the Telephone Interview for Cognitive Status Scale and Medical Outcomes Study 36-Item Short Form Health Survey. The relationships among age, POD, declined cognitive function, and QoL were tested using path analysis.

RESULTS

Declined cognitive function was associated with poorer QoL. POD was associated with declined cognitive function but was not associated with poorer QoL. Ageing was not associated with QoL but was associated with POD and declined cognitive function.

CONCLUSION

The QoL of patients developed delirium after CABG is determined by cognitive function after discharge. Necessary strategies should be implemented to prevent POD and declined cognitive function, especially in elderly patients.

Mind Over Matter? The Hidden Epidemic of Cognitive Dysfunction in the Older Surgical Patient

OBJECTIVE

The aim of this study was to highlight the vulnerability of the aging brain to surgery and anesthesia, examine postoperative cognitive outcomes, and recommend possible interventions.

BACKGROUND

Surgeons are facing increasingly difficult ethical and clinical decisions given the rapidly expanding aging demographic. Cognitive function is not routinely assessed either preoperatively or postoperatively. Potential short and long-term cognitive implications are rarely discussed with the patient despite evidence that postoperative cognitive impairment occurs in up to 65% of older patients. Furthermore, surgery may accelerate the trajectory of cognitive decline and dementia.

METHODS

An electronic search was conducted using Pubmed/Medline. References from selected studies were cross-referenced and relevant articles retrieved. Data were summarized in a narrative format.

RESULTS

There is a hidden epidemic of cognitive dysfunction in the perioperative setting. Up to 40% of patients who develop postoperative delirium (POD) never return to their preoperative cognitive baseline. POD can lead to postoperative cognitive dysfunction (POCD), a more prolonged cognitive impairment associated with longer length of hospital stay and cost, premature withdrawal from the workforce, and greater 1-year mortality. Standardized perioperative cognitive assessment is needed to enable progress. Improving outcomes will depend on a multifaceted approach, including correction of modifiable preoperative risk factors and prompt treatment of POD. Risk factors are discussed and possible interventional strategies are presented.

CONCLUSION

Closer preoperative collaboration between surgeons, geriatricians, and anesthetists will enable identification of complex at-risk older patients. A paradigm shift in the approach to management of the older surgical patient is critical to improve postoperative cognitive outcomes in modern surgery.

Risk factors for postoperative delirium in patients undergoing vascular surgery

OBJECTIVE

Postoperative delirium (PODE) remains a common complication after vascular surgery procedures although the exact pathogenesis remains unclear, mainly because of its multifactorial character. The aim of this systematic review was to evaluate pooled data on potential risk factors for PODE in patients undergoing vascular surgery procedures.

METHODS

A systematic literature review was conducted conforming to established criteria to identify eligible articles published from 1990 to 2016. Eligible studies evaluated potential risk factors for PODE after vascular surgery procedures, using both univariate and multivariate analysis. PODE was defined as a disturbance of consciousness with reduced ability to focus, sustain, or shift attention after vascular surgery procedures and was diagnosed in all studies using well-established criteria. Only risk factors reported in at least four studies were included in this review. Pooled results were calculated, and further multivariate regression analysis was conducted.

RESULTS

Overall, nine studies (published from 2003 to 2015) including 2388 patients in total were evaluated (457 with and 1931 without PODE). Patients with PODE were older (73.27 vs 69.87 years; P < .0001) and showed a higher male sex rate (78.1% vs 73.5%; P = .043). Open aortic surgery was the most frequent procedure in this analysis, followed by lower limb revascularization. Patients with PODE also showed higher rates of diabetes mellitus, hypertension, cardiac disease, and neurologic disease; lower hemoglobin level; larger duration of surgery; longer hospital and intensive care unit stay; and higher blood loss. Mean age (odds ratio [OR], 3.44; 95% confidence interval [CI], 2.933-4.034; P < .0001), hypertension (OR, 1.94; 95% CI, 1.469-2.554; P < .0001), cardiac disease (OR, 3.16; 95% CI, 2.324-4.284; P < .0001), open aortic surgery (OR, 1.74; 95% CI, 1.421-2.143; P < .0001), blood loss (OR, 1.01; 95% CI, 1.007-1.010; P < .0001), hospital stay (OR, 2.26; 95% CI, 1.953-2.614; P <. 0001), and intensive care unit stay (OR, 6.12; 95% CI, 4.699-7.957; P < .0001) were identified as the strongest risk predictors for PODE, followed by male sex, diabetes mellitus, neurologic disease, and history of smoking. However, body mass index, renal failure, preoperative hemoglobin level, and general anesthesia were not found to be risk factors for PODE in such patients.

CONCLUSIONS

This study has confirmed that PODE after vascular surgery procedures is a multifactorial disease, and several independent risk factors have been identified. However, pooled data regarding the effect of PODE on primary outcomes after vascular surgery procedures are still lacking. The results of this review could contribute to the designation of future prediction models and improve prevention of PODE in these patients.

Perioperative care in elderly cardiac surgery patients

Introduction

Surgery is an extreme physiological stress for the elderly. Aging is inevitably associated with irreversible and progressive cellular degeneration. Patients above 75 years of age are characterized by impaired responses to operative stress and a very narrow safety margin.

Aim

To evaluate perioperative complications in patients aged ≥ 75 years who underwent cardiac surgery in comparison to outcomes in younger patients.

Material and methods

The study was conducted at the Silesian Centre for Heart Diseases in Zabrze in 2009–2014 after a standard of perioperative care in seniors was implemented to reduce complications, in particular to decrease the duration of mechanical ventilation and reduce postoperative delirium. The study group included 1446 patients.

Results

The mean duration of mechanical ventilation was 13.8 h in patients aged ≥ 75 years and did not differ significantly compared to younger patients. In-hospital mortality among seniors was 3.8%, a value significantly higher than that observed among patients younger than 75 years of age. Patients aged ≥ 75 years undergoing cardiac surgery have significantly more concomitant conditions involving other organs, which affects treatment outcomes (duration of hospital stay, mortality).

Conclusions

The implementation of a standard of perioperative care in this age group reduced the duration of mechanical ventilation and lowered the rate of postoperative delirium.

Discrepancy between electroencephalography and hemodynamics in a patient with Cockayne syndrome during general anesthesia

Cockayne syndrome is a kind of progeria with autosomal chromosome recessiveness described first by Cockayne in 1936. Patients with this syndrome were characterized by retarded growth, cerebral atrophy, and mental retardation. We experienced an anesthetic management of a patient with Cockayne syndrome, who underwent dental treatment twice. The primary concern was discrepancy between electroencephalography and hemodynamics. The values of bispectral index showed a sharp fall to 1 digit and suppression ratio more than 40, while hemodynamics was stable during induction of anesthesia with sevoflurane 8%. We should pay attention to anesthetic depth in the central nervous system in patients with Cockayne syndrome. Titration of anesthetics should be performed by the information from electroencephalography.

A comparison of general versus regional anesthesia for hip fracture surgery: a meta-analysis

In this study, we aimed to compare the effect of general versus regional anesthesia on postoperative outcomes in patients undergoing surgical repair of hip fracture. Randomized controlled trials, prospective studies and retrospective observational studies were searched in PubMed, Medline and Embase database published between January 2005 and March 2014. The overall outcome was measured by odds ratios (ORs) and risk ratios (RRs) with their corresponding 95% confidence intervals (CIs). A total of 7 trials, involving 36448 patients received general anesthesia and 33952 patients received regional anesthesia, were included in present meta-analysis. We found that the 30-day mortality rate was lower in general anesthesia cases than that in regional cases (5.3% vs. 6.3%). Overall, our results demonstrated that there was no significant difference in 30-day mortality between two types of anesthesia in patients with hip fracture surgery (RR=0.98, 95% CI=0.92-1.04, P=0.48), indicating that types of anesthesia might not be a risk factor for hip fracture surgery. No statistically significant difference was observed in other outcome measures (P>0.05). In conclusion, our results suggested that the choice of anesthesia (general or regional) should be made by the anesthesiologist on an individual basis and based on the patient's medical conditions. Further research is still needed to evaluate the effect of these two anesthesia methods.

Sevoflurane

Sevoflurane has been available for clinical practice for about 20 years. Nowadays, its pharmacodynamic and pharmacokinetic properties together with its absence of major adverse side effects on the different organ systems have made this drug accepted worldwide as a safe and reliable anesthetic agent for clinical practice in various settings.

Can the dopaminergic-related effects of general anesthetics be linked to mechanisms involved in drug abuse and addiction?

BACKGROUND

General anesthetics (GA) are well known for the ability to induce a state of reversible loss of consciousness and unresponsiveness to painful stimuli. However, evidence from animal models and clinical studies show that GA exposure may induce behavioral changes beyond acute effects. Most research and concerns are focused on changes in cognition and memory.

METHODS

We will look at effects of GA on behavior that is mediated by the dopaminergic system.

RESULTS

Pharmacological resemblance of GA with drugs of abuse, and the complexity and importance of dopaminergic systems in both reward seeking and addictive illnesses make us believe that it deserves an overview about what is already known and what matters to us as healthcare workers and specifically as anesthesiologists.

CONCLUSION

A review of available evidence strongly suggests that there may be a link between the effects of GA on the brain and substance abuse, partly explained by their influence on the dopaminergic system.

Sevoflurane and Isoflurane induce structural changes in brain vascular endothelial cells and increase blood-brain barrier permeability: Possible link to postoperative delirium and cognitive decline

A large percentage of patients subjected to general anesthesia at 65 years and older exhibit postoperative delirium (POD). Here, we test the hypothesis that inhaled anesthetics (IAs), such as Sevoflurane and Isoflurane, act directly on brain vascular endothelial cells (BVECs) to increase blood-brain barrier (BBB) permeability, thereby contributing to POD. Rats of young (3-5 months), middle (10-12 months) and old (17-19 months) ages were anesthetized with Sevoflurane or Isoflurane for 3h. After exposure, some were euthanized immediately; others were allowed to recover for 24h before sacrifice. Immunohistochemistry was employed to monitor the extent of BBB breach, and scanning electron microscopy (SEM) was used to examine changes in the luminal surfaces of BVECs. Quantitative immunohistochemistry revealed increased BBB permeability in older animals treated with Sevoflurane, but not Isoflurane. Extravasated immunoglobulin G showed selective affinity for pyramidal neurons. SEM demonstrated marked flattening of the luminal surfaces of BVECs in anesthetic-treated rats. Results suggest an aging-linked BBB compromise resulting from exposure to Sevoflurane. Changes in the luminal surface topology of BVECs indicate a direct effect on the plasma membrane, which may weaken or disrupt their BBB-associated tight junctions. Disruption of brain homeostasis due to plasma influx into the brain parenchyma and binding of plasma components (e.g., immunoglobulins) to neurons may contribute to POD. We propose that, in the elderly, exposure to some IAs can cause BBB compromise that disrupts brain homeostasis, perturbs neuronal function and thereby contributes to POD. If unresolved, this may progress to postoperative cognitive decline and later dementia.

Comparison of frequency, risk factors, and time course of postoperative delirium in octogenarians after transcatheter aortic valve implantation versus surgical aortic valve replacement

Postoperative delirium (PD) after transcatheter aortic valve implantation (TAVI) remains to be explored. We sought to (1) determine the incidence of PD in octogenarians who underwent TAVI or surgical aortic valve replacement (SAVR), (2) identify its risk factors, and (3) describe possible differences in the onset and course of PD between treatment groups. A prospective cohort study of consecutive patients aged ≥80 years with severe aortic stenosis who underwent elective TAVI or SAVR (N = 143) was conducted. The incidence of PD was assessed for 5 days using the Confusion Assessment Method (CAM). Risk factors for PD were studied with logistic regression. Patients treated with TAVI were older (p ≤0.001), had lower cognitive scores (p = 0.007), and more co-morbidities (p = 0.003). Despite this, significantly fewer (p = 0.013) patients treated with TAVI (44%) experienced PD compared to patients treated with SAVR (66%). Undergoing SAVR (p = 0.02) and having lower cognitive function (p = 0.03) emerged as risk factors for PD, whereas gender, activities of daily living, frailty, atrial fibrillation, and postoperative use of opioids and anxiolytics did not. Patients treated with TAVI and without PD during the first 2 postoperative days were unlikely to experience PD on subsequent days. The onset of PD after SAVR could occur at any time during the postoperative evaluation. In conclusion, SAVR in octogenarian patients with aortic stenosis might be considered as a predisposing factor for PD. Our data also suggest that the onset of PD was more unpredictable after SAVR.