Postoperative Cognitive Function as an Outcome of Regional Anesthesia and Analgesia:

Effects of different anesthetic regimens on postoperative cognitive function of elderly patients undergoing thoracic surgery: a double-blinded randomized controlled trial

OBJECTIVE

Postoperative cognitive dysfunction (POCD) is a serious surgical complication. We assessed the different POCD incidences between anesthesia using sevoflurane and sevoflurane combined with dexmedetomidine, with propofol-based sedation in elderly patients who underwent a thoracic surgical procedure.

METHODS

A total of 90 patients aged 65 to 80 years old who underwent a thoracic surgical procedure at our hospital and 15 nonsurgical participants as controls, were enrolled in this study. Patients were divided in a randomized 1:1:1 ratio into 3 groups. All participants were randomized into a trial with three anesthesia groups (P, PS, PSD) or a control group (C) of healthy matches. All trial groups received distinct anesthetic combinations during surgery, while controls mirrored patient criteria.Group P (propofol and remifentanil were maintained during the surgery), Group PS (propofol, remifentanil, and sevoflurane were maintained during the surgery), and Group PSD (propofol, remifentanil, sevoflurane, and dexmedetomidine were maintained during the surgery).All participants were rated using a series of cognitive assessment scales before and three days after surgery. All participants were interviewed over the telephone, 7 days, 30 days, and 90 days postoperatively.

RESULTS

POCD incidences in the PSD (combined anesthetization with propofol, sevoflurane, and dexmedetomidine) group was significantly lower than that in the PS (combined anesthetization with propofol and sevoflurane) group, 1 day post-surgery (10.0% vs. 40.0%, P = 0.008), and the results were consistent at 3 days post-surgery. When the patients were assessed 7 days, 30 days, and 90 days postoperatively, there was no significant difference in POCD incidence among the three groups. Multivariate logistic regression analysis of POCD one day after surgery showed that education level was negatively correlated with incidence of POCD (P = 0.018) and single lung ventilation time was positively correlated with incidence of POCD (P = 0.001).

CONCLUSION

For elderly patients who underwent a thoracic surgical procedure, dexmedetomidine sedation shows an obvious advantage on improving short-term POCD incidence, which is caused by sevoflurane.

Postoperative cognitive dysfunction: a concept analysis

BACKGROUND

Post-operative cognitive dysfunction (POCD) is a concern for clinicians that often presents post-surgery where generalized anesthesia has been used. Its prevalence ranges from 36.6% in young adults to 42.4% in older individuals. Conceptual clarity for POCD is lacking in the currently body literature. Our two-fold purpose of this concept analysis was to (1) critically appraise the various definitions, while also providing the best definition, of POCD and (2) narratively synthesize the attributes, surrogate or related terms, antecedents (risk factors), and consequences of the concept.

METHOD

The reporting of our review was guided by the PRISMA statement and the 6-step evolutionary approach to concept analysis developed by Rodgers. Three databases, including Medline, CINAHL, and Web of Science, were searched to retrieve relevant literature on the concept of POCD. Two independent reviewers conducted abstract and full-text screening, data extraction, and appraisal. The review process yielded a final set of 86 eligible articles.

RESULT

POCD was defined with varying severities ranging from subtle-to-extensive cognitive changes (1) affecting single or multiple cognitive domains that manifest following major surgery (2), is transient and reversible, and (3) may last for several weeks to years. The consequences of POCD may include impaired quality of life, resulting from withdrawal from the labor force, increased patients' dependencies, cognitive decline, an elevated risk of dementia, rising healthcare costs, and eventual mortality.

CONCLUSION

This review resulted in a refined definition and comprehensive analysis of POCD that can be useful to both researchers and clinicians. Future research is needed to refine the operational definitions of POCD so that they better represent the defining attributes of the concept.

Postoperative neurocognitive disorders: A clinical guide

For years, postoperative cognitive outcomes have steadily garnered attention, and in the past decade, they have remained at the forefront. This prominence is primarily due to empirical research emphasizing their potential to compromise patient autonomy, reduce quality of life, and extend hospital stays, and increase morbidity and mortality rates, especially impacting elderly patients. The underlying pathophysiological process might be attributed to surgical and anaesthesiological-induced stress, leading to subsequent neuroinflammation, neurotoxicity, burst suppression and the development of hypercoagulopathy. The beneficial impact of multi-faceted strategies designed to mitigate the surgical and perioperative stress response has been suggested. While certain potential risk factors are difficult to modify (e.g., invasiveness of surgery), others - including a more personalized depth of anaesthesia (EEG-guided), suitable analgesia, and haemodynamic stability - fall under the purview of anaesthesiologists. The ESAIC Safe Brain Initiative research group recommends implementing a bundle of non-invasive preventive measures as a standard for achieving more patient-centred care. Implementing multi-faceted preoperative, intraoperative, and postoperative preventive initiatives has demonstrated the potential to decrease the incidence and duration of postoperative delirium. This further validates the importance of a holistic, team-based approach in enhancing patients' clinical and functional outcomes. This review aims to present evidence-based recommendations for preventing, diagnosing, and treating postoperative neurocognitive disorders with the Safe Brain Initiative approach.

Effect of preoperative hospitalisation period on postoperative cognitive dysfunction in patients undergoing hip surgery under regional anaesthesia

AIM OF THE STUDY

The main objective of this prospective and observational study was to investigate the effect of the preoperative hospitalisation period on early postoperative cognitive dysfunction (POCD) development in patients undergoing total hip replacement surgery under regional anaesthesia.

MATERIALS AND METHODS

Between November 2013 and September 2014, 64 patients were enrolled in the study. Mini Mental Test (MMT) scores were obtained on the initial admission day (MMT1), 24 hours prior to the surgery (MMT2) and 24 hours after the surgery (MMT3). The patients were divided into two groups according to the MMT scores: 'no cognitive dysfunction' (group 1) and 'cognitive dysfunction' (group 2). Differences between the groups were evaluated statistically. The statistical significance level was set as P < .05 in a 95% confidence interval.

RESULTS

The POCD incidence rate was calculated as 43.8% in all patients. The preoperative hospitalisation duration was significantly longer in patients with POCD than in patients without POCD (P < .001). The factors that affected POCD development were found to be advanced age (P < .001), high American Society of Anesthesiologists scores (P = .004), the presence of comorbid disease (P = .025), durations of surgery (P = .018) and decreased postoperative haematocrit levels (P = .014).

CONCLUSION

In this study, we observed that patients with early POCD had relatively longer preoperative hospitalisation periods than those in patients without POCD. We consider that prolonged preoperative hospitalisation may contribute to increased POCD incidence rates in patients with risk factors.

Cognitive impairment assessment and interventions to optimize surgical patient outcomes

For elderly patients undergoing elective surgical procedures, preoperative evaluation of cognition is often overlooked. Patients may experience postoperative delirium (POD) and postoperative cognitive decline (POCD), especially those with certain risk factors, including advanced age. Preoperative cognitive impairment is a leading risk factor for both POD and POCD, and studies have noted that identifying these deficiencies is critical during the preoperative period so that appropriate preventive strategies can be implemented. Comprehensive geriatric assessment is a useful approach which evaluates a patient's medical, psycho-social, and functional domains objectively. Various screening tools are available for preoperatively identifying patients with cognitive impairment. The Enhanced Recovery After Surgery (ERAS) protocols have been discussed in the context of prehabilitation as an effort to optimize a patient's physical status prior to surgery and decrease the risk of POD and POCD. Evidence-based protocols are warranted to standardize care in efforts to effectively meet the needs of these patients.

Effect of anesthetic method on incidence of delirium after total hip replacement arthroplasty in South Korea: a population-based study using National Health Insurance claims data

Background

There are various reports on the effects of the anesthetic method on neurologic complications. A population-based study was conducted to estimate the effect of anesthetic method on the incidence of postoperative delirium in patients that underwent total hip replacement arthroplasty in South Korea.

Methods

The Korean National Health Insurance claims database was used to retrospectively identify and analyze 24,379 cases of total hip replacement arthroplasty, defined as patients having a claim record with the operation code ‘N0711,’ from January 2008 to December 2017. Patients were divided into two groups, a general anesthesia group (n = 9,921) and a regional anesthesia group (n = 14,458). The incidence of delirium was assessed in cases when patients used medications for delirium, such as haloperidol, chlorpromazine, olanzapine, and risperidone.

Results

Of the 9,921 patients receiving general anesthesia and 14,458 receiving regional anesthesia, 142 (1.43%) and 209 (0.86%) experienced postoperative delirium after total hip replacement arthroplasty, respectively. There was no significant difference between the groups (P = 0.92). In logistic regression analysis, sex (P = 0.038) and patients with acquired immune deficiency syndrome (P = 0.008) were predictors of postoperative delirium.

Conclusions

Our results revealed that the anesthetic method was not associated with the incidence of postoperative delirium. In addition, the results suggest that male patients and patients with acquired immune deficiency syndrome undergoing total hip replacement arthroplasty carefully managed for postoperative delirium after surgery.

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.

Oxidative stress and mitochondrial dysfunction contributes to postoperative cognitive dysfunction in elderly rats

Postoperative cognitive dysfunction (POCD) is defined by cognitive impairment determined by neuropsychological tests from before to after surgery. Several mechanisms have been proposed in this bidirectional communication between the immune system and the brain after surgery. We aimed at understanding the mechanisms underlying POCD elderly rats in an experimental tibial fracture model. Elderly male Wistar rats were subjected to tibial fracture (TF) model. Control (sham) and fracture (TF) groups were followed to determine nitrite/nitrate concentration; oxidative damage to lipids and proteins; the activity of antioxidant enzymes (superoxide dismutase-SOD and catalase-CAT), mitochondrial respiratory chain enzymes, and creatine kinase (CK); and BDNF levels in the hippocampus and prefrontal cortex (at 24 h and at seven days) and cognitive function through habituation to the open field task and novel object recognition task (only at seven days). TF group presented increased concentration of nitrite/nitrate, hippocampal lipid peroxidation at seven days, protein oxidative damage in the prefrontal cortex and hippocampus at 24 h, decreased antioxidant activity in both structures on the first postoperative day and compromised function of the mitochondrial respiratory chain complexes as well as the CK enzyme. In addition, the levels of BDNF were reduced and memory function was impaired in the TF group. In conclusion, elderly rats submitted to an experimental model of tibial fracture displayed memory impairment accompanied by an increase in oxidative stress, mitochondrial dysfunction and reduced neurotrophin level.

Anesthesia and analgesia for total knee arthroplasty

The demand for total knee arthroplasty (TKA) is rising worldwide. Controversy persists in the literature regarding the benefits of general versus neuraxial anesthesia and which anesthetic is associated with the best outcomes. Likewise, the abundance of analgesic options for post-TKA pain have led to debate regarding the safest, most effective regimens. In this paper, we evaluated a selection of recent publications regarding anesthetic and analgesic choices for TKA. High-quality studies and meta-analyses linking anesthetic agents and analgesic modalities to clinically important outcomes were chosen wherever possible. We included a range of clinical and population-based research, incorporating established and emerging techniques. Although not uniform, clinical and population-based data favor neuraxial anesthesia, and suggest less morbidity compared to general anesthesia. There is good evidence to support an opioid-minimizing, multimodal approach to post-TKA analgesia, featuring peripheral nerve blocks and/or peri-articular injection. The recently described IPACK (interspace between the popliteal artery and posterior capsule of the knee) block may address posterior knee pain after TKA. Ultrasound-guided regional analgesia techniques are cost and clinically effective. Liposomal bupivacaine represents an expanding topic of research in TKA-analgesia, but currently, data do not support routine use. Evidence to guide the creation of pathways of care for TKA abounds, but must be tailored to local practice to maximize chances of success. Recent data supports the use of neuraxial anesthesia and regional analgesia techniques for TKA. Recommendations for clinical practice and future research to improve the state of the art are provided.

Anesthesia and the risk of dementia in the elderly

Cognitive complications are common after surgery in the elderly, and with an increased number of elderly patients undergoing surgery, a potential impact of anaesthesia and surgery on long term cognition, and especially dementia would be concerning. The question whether anaesthesia and surgery in itself induce structural changes in the brain and thereby cognitive deterioration, or reveal a preexisting cognitive impairment remains unresolved. Several studies show an increased risk of reversible cognitive impairment after surgery in the elderly, but the risk of inducing dementia remains speculative. Further studies are needed to elucidate this potential association. Meanwhile, elderly frail patients need to be closely followed including preoperative cognitive screening, since they are at increased risk of cognitive deterioration after surgery and discharge.

Preemptive Caudal Ropivacaine: An Effective Analgesic during Degenerative Lumbar Spine Surgery

Study Design

This was a prospective, randomized, controlled trial comprising 60 patients undergoing lumbosacral spine (noninstrumentation/nonfusion) surgery.

Purpose

The purpose of this study was to evaluate the efficacy of 0.2% ropivacaine (20 mL) administered alone as a single, preoperative, caudal epidural block injection versus that of intravenous analgesics in providing effective postoperative analgesia to patients undergoing lumbosacral spine surgery.

Overview of Literature

Various studies have shown the effectiveness of a caudal epidural injection (bupivacaine or ropivacaine) in providing postoperative analgesia in combination with steroids or other analgesics. This study uniquely analyzed the efficacy of a single injection of caudal epidural ropivacaine in providing postoperative pain relief.

Methods

Sixty patients who were scheduled to undergo surgery for degenerative lumbar spine disease (noninstrumentation/nonfusion) were consecutively divided into two groups, group R (Study) and group I (Control). 30 group R patients received a caudal epidural block with 20 mL of 0.2% ropivacaine after the administration of general anesthesia. 30 group I patients received no preoperative analgesia. Intravenous analgesics were administered during the postoperative period after a complaint of pain. Various parameters indicating analgesic effect were recorded.

Results

There was a significant delay in the average time to the first demand for rescue analgesia in the study group, suggesting significantly better postoperative pain relief than that in the control group. In comparison with the control group, the study group also showed earlier ambulation with minimal adverse effects. The requirement for intraoperative fentanyl was higher in the control group than that in the study group.

Conclusions

Preemptive analgesia with a single epidural injection of ropivacaine is a safe, simple, and effective approach, providing better postoperative pain relief, facilitating early mobilization, and decreasing the intraoperative requirement for opioid administration.

Neurologic Complications in Noncardiac Surgery

In this article, the incidence of nervous system injuries associated with noncardiac surgery is reviewed briefly. In general, these can be divided into injuries that are clinically apparent (eg, stroke or peripheral nerve damage), which may generally be detectable on clinical examination, and more subtle forms of brain injury (eg, personality changes and postoperative cognitive dysfunction), injuries that are primarily detected by neuropsychological testing.

Regional Anesthesia in Cardiac Surgery: A Friend or A Foe?

Escalating costs and change in the profile of patients presenting for cardiac surgery requires modification of perioperative management strategies. Regional anesthesia has played an integral part of many fast-track anesthesia protocols across North America and Europe. This review suggests that for patients undergoing coronary artery bypass graft surgery, the risk-to-benefit ratio is in favor of epidural and spinal anesthesia, provided there are no specific contraindications and the guidelines for the use of regional techniques in cardiac surgery are followed. Patients managed with regional techniques seem to benefit from superior postoperative analgesia, shorter postoperative ventilation, reduced incidence of supraventricular arrhythmia, and lower rates of perioperative myocardial infarction. The results of this analysis suggest that for each episode of neurologic complication, 20 myocardial infarctions and 76 episodes of atrial fibrillation would be prevented, thus, we would consider the regional anesthesia and analgesia to be an effective strategy that improves perioperative morbidity. However, other treatment modalities such as the addition of calcium channel blockers, aspirin, and beating heart surgery, are also suggested to be beneficial in cardiac surgical patients and may impose less risk than the use of regional techniques. We believe that the results presented in this review are encouraging enough to permit continued investigation. A prospective, randomized, controlled multicenter trial needs to be adequately powered to answer important clinical questions and allow for a long-term follow-up.

[The effects of memantine on recovery, cognitive functions, and pain after propofol anesthesia]

OBJECTIVES

Postoperative cognitive dysfunction refers to the problems associated with thought and memory that are often experienced after major surgery. The aim of this study is to evaluate the effects of intraperitoneally administered memantine on recovery, cognitive functions, and pain after propofol anesthesia.

METHODS

The study was conducted in Gazi University Animal Research Laboratory, Ankara, Turkey in January 2012. Twenty-four adult female Wistar Albino rats weighing 170-270g were educated for 300s in the radial arm maze (RAM) over three days. Group P was administered 150mgkg(-1) of intraperitoneal (IP) propofol; Group M was given 1mgkg(-1) of IP memantine; and Group MP was given 1mgkg(-1) of IP memantine before being administered 150mgkg(-1) of IP propofol. The control group received only IP saline. RAM and hot plate values were obtained after recovery from the groups that received propofol anesthesia and 30min after the administration of drugs in other two groups.

RESULTS

The duration of recovery for Group MP was significantly shorter than Group P (p<0.001), and the number of entries and exits in the RAM by Group MP was significantly higher during the first hour when compared to Group P (p<0.0001). Hot plate values, on the other hand, were found to be significantly increased in all groups when compared to the control values, aside from Group C (p<0.0001).

CONCLUSION

In this study, memantine provided shorter recovery times, better cognitive functions, and reduced postoperative pain. From this study, we find that memantine has beneficial effects on recovery, cognitive functions, and pain after propofol anesthesia.

Assessment of selected cognitive processes in elderly patients after urologic surgery

INTRODUCTION

The issue of postoperative disorders of cognitive functions is a highly topical problem as more and more elderly people undergo medical treatments. Patients may lose the ability of assimilating information and their linguistic functions may deteriorate. Cognitive disorders may result in the temporary exclusion of the patient from social activity.

AIM

The purpose of the paper was to assess the incidence of certain cognitive disorders in the elderly after urological surgeries.

MATERIAL AND METHODS

The study was conducted in a group of 218 patients aged over 65, male and female, after an urological surgery under different types of anesthesia. Standardized neuropsychological tests of cognitive functions were employed in the study.

RESULTS

Analysis of the data showed that in the control group were obtained similar results in the study of the first and second. However, in the test group demonstrated a reduction cognitive function in all the tests in a second study.

CONCLUSIONS

The reduction of cognitive functions in the study group was observed in all the domains but it was the most marked in visual memory tests. Postoperative reduction of cognitive functions is correlated with the patient's age, education and mood. Postoperative reduction of cognitive functions is not correlated with the type of surgery, anesthesia and its duration.

The effects of memantine on recovery, cognitive functions, and pain after propofol anesthesia

OBJECTIVES

Postoperative cognitive dysfunction refers to the problems associated with thought and memory that are often experienced after major surgery. The aim of this study is to evaluate the effects of intraperitoneally administered memantine on recovery, cognitive functions, and pain after propofol anesthesia.

METHODS

The study was conducted in Gazi University Animal Research Laboratory, Ankara, Turkey in January 2012. Twenty-four adult female Wistar Albino rats weighing 170-270g were educated for 300s in the radial arm maze (RAM) over three days. Group P was administered 150mgkg(-1) of intraperitoneal (IP) propofol; Group M was given 1mgkg(-1) of IP memantine; and Group MP was given 1mgkg(-1) of IP memantine before being administered 150mgkg(-1) of IP propofol. The control group received only IP saline. RAM and hot plate values were obtained after recovery from the groups that received propofol anesthesia and 30min after the administration of drugs in other two groups.

RESULTS

The duration of recovery for Group MP was significantly shorter than Group P (p<0.001), and the number of entries and exits in the RAM by Group MP was significantly higher during the first hour when compared to Group P (p<0.0001). Hot plate values, on the other hand, were found to be significantly increased in all groups when compared to the control values, aside from Group C (p<0.0001).

CONCLUSION

In this study, memantine provided shorter recovery times, better cognitive functions, and reduced postoperative pain. From this study, we find that memantine has beneficial effects on recovery, cognitive functions, and pain after propofol anesthesia.

Perioperative Cognitive Protection-Cognitive Exercise and Cognitive Reserve (The Neurobics Trial): A Single-blind Randomized Trial

PURPOSE

The Neurobics Trial is a single-blind, parallel-group, randomized, controlled trial. The main study objective is to compare effectiveness of preoperative cognitive exercise versus no intervention for lowering the incidence of postoperative delirium. Enrollment began March 2015 and is ongoing.

METHODS

Eligible participants include patients older than 60 years of age scheduled for nonemergent, noncardiac, nonneurological surgery at our institution. Patients provide consent and are screened at our Outpatient Preoperative Assessment Clinic to rule out preexisting cognitive dysfunction, significant mental health disorders, and history of surgery requiring general anesthesia in the preceding 6 months. Participants meeting criteria are randomized to complete 1 hour daily of electronic tablet-based cognitive exercise for 10 days before surgery or no preoperative intervention. Compliance with the effective dose of 10 total hours of preoperative exercise is verified on return of the patient for surgery with time logs created by the software application and by patient self-reporting. After surgery, patients are evaluated for delirium in the postanesthesia recovery area, and then twice daily for the remainder of their hospitalization. Additionally, postoperative quality of recovery is assessed daily, along with pain scores and opiate use. More comprehensive cognitive assessments are completed just before discharge for baseline comparison, and quality of recovery is assessed via telephone interview 7, 30, and 90 days post-surgery. The primary outcome is the incidence of delirium during the postoperative hospitalization period. Randomization is computer generated, with allocation concealment in opaque envelopes. All postoperative assessments are completed by blinded study personnel.

FINDINGS

The study is actively recruiting with 19 patients having provided consent to date, and a total of 264 patients is required for study completion; therefore, no data analysis is currently under way (www.clinicaltrials.gov; NCT02230605).

IMPLICATIONS

To our knowledge, the Neurobics Trial is the first randomized, controlled study to investigate the effectiveness of a significant preoperative cognitive exercise regimen for the prevention of delirium after noncardiac, nonneurological surgery in elderly patients.

Single shot spinal anesthesia with very low hyperbaric bupivacaine dose (3.75 mg) for hip fracture repair surgery in the elderly. A randomized, double blinded study

PURPOSE

Single shot spinal anesthesia is used worldwide for hip fracture repair surgery in the elderly. Arterial hypotension is a frequent adverse effect. We hypothesized that lowering local anesthetics dose could decrease the incidence of arterial hypotension, while maintaining quality of surgical anesthesia.

METHODS

In a randomized double blinded study, 66 patients over the age of 65 years, with hip fracture needing surgical repair, were assigned to B0.5 group 7.5mg hyperbaric bupivacaine 5mg/ml (control group), and B0.25 group 3.75mg hyperbaric bupivacaine 2.5mg/ml (study group). Sensory and motor block level, and hemodynamic parameters including blood presure, heart rate and vasopressor dose administration were registered, along with rescue anesthesia needs, the feasibility of surgery, its duration, and regression time of sensory anesthesia to T12.

RESULTS

After exclusions, 61 patients were included in the final analysis. Arterial hypotension incidence was lower in the B0.25 group (at the 5, 10, and 15min determinations), and a lower amount of vasopressor drugs was needed (mean accumulated ephedrine dose 1.6mg vs. 8.7mg in the B0.5 group, p<0.002). Sensory block regression time to T12 was shorter in the B0.25 group, mean 78.6±23.6 (95% CI 51.7-110.2)min vs. 125.5±37.9 (95% CI 101.7-169.4)min in the B0.5 group, p=0.033. All but one patient in the B0.25 group were operated on under the anesthetic procedure first intended. No rescue anesthesia was needed.

CONCLUSION

Lowering bupivacaine dose for single shot spinal anesthesia for hip fracture repair surgery in elderly patients was effective in decreasing the occurrence of arterial hypotension and vasopressor use, while intraoperative quality remained.

Single shot spinal anaesthesia with hypobaric bupivacaine for hip fracture repair surgery in the elderly. Randomized, double blinded comparison of 3.75 mg vs. 7.5 mg

BACKGROUND

Arterial hypotension is the most frequent adverse effect of subarachnoid anaesthesia in the elderly sustaining a femoral proximal fracture. Decreasing the local anaesthetic dose reduces the incidence of hypotension but shortens sensory block duration that could be insufficient in some surgical procedures. Sensory block duration could be prolonged using hypobaric local anaesthetics. We evaluated whether low hypobaric bupivacaine doses were adequate for this type of surgery while maintaining the haemodynamic stability.

METHODS

A prospective, randomized, double blinded study was designed. Patients over 65 years old, sustaining traumatic hip fracture, were assigned to one of two groups: B0.5 group, hypobaric bupivacaine 7.5mg 5mg/ml (control group), and B0.25 group, hypobaric bupivacaine 3.75 mg 2.5mg/ml (study group). After subarachnoid injection, sensory level and motor blockade degree were registered, as were blood pressure, and heart rate at basal time and at 2, 5, 10, 15, 20 and 30 min after injection. The doses of vasopressor needed were registered as well. Surgical conditions and the duration of the surgical procedure-whether rescue analgesia or anaesthesia was needed-and sensory level regression to T12, were registered as well.

RESULTS

Sixty four patients was the calculated sample size. The study was stopped in an interim analysis because an elevated number of patients in the B0.25 group needed iv rescue anaesthesia. In the analyzed cases, blood pressure was significantly lower in the B0.5 group at the 15 and 30 min measurements. Vasopressor drugs needs were similar between groups [ephedrine accumulated mean (SD) doses 11.4 (5.2) mg vs. 9.1 (2.7) mg, p=0.045)]. Sensory block regression to T12 was faster in the B0.25 group, [(mean (SD) 68.2 (29.0) min vs. 112.8 (17.3) min in the B0.5 group, p<0.05]. Five out of 19 patients in the B0.25 group needed intravenous anaesthesia rescue before surgery started.

CONCLUSION

Lowering hypobaric bupivacaine dose to 3.75 mg in subarachnoid anaesthesia for hip fracture repair surgery in elderly patients decrease intraoperative blood pressure, but in an important number of patients intravenous anaesthesia rescue was needed and preclude recommendation.

Type of anesthesia and postoperative delirium after vascular surgery

OBJECTIVE

The purpose of this study was to investigate the association between general (GA), regional (RA), and local (LA) anesthetic techniques with respect to the development of delirium after vascular surgery. The authors hypothesized that patients undergoing GA for vascular surgery would have a higher incidence of postoperative delirium. The role of LA with respect to postoperative delirium in vascular surgery patients previously has not been reported.

DESIGN

Retrospective review.

SETTING

Tertiary referral center, university hospital.

PARTICIPANTS

500 patients undergoing vascular surgical procedures.

INTERVENTIONS

Based on the chosen anesthetic technique, all patients were divided into GA, RA, and LA groups, respectively. Exclusion criteria were patients with preoperative dementia or abnormal level of consciousness, patients undergoing open abdominal aneurysm repair surgery, and patients undergoing carotid endarterectomy. All anesthetic techniques were conducted according to routine institutional practices. Patients in both the RA and LA groups received intravenous sedation.

MEASUREMENTS AND MAIN RESULTS

Three hundred ninety-six (79%) patients received GA, 73 (15%) RA, and 31 (6%) LA. The overall incidence of delirium was 19.4% and rates were similar among the 3 groups, with 73 (18.4%) patients in the GA group, 17 (23.2%) in the RA group, and 7 (22.5%) in the LA group (p = 0.56). Patients in the LA group were more likely to have emergency surgery and also had a higher incidence of previous cerebrovascular accidents or transient ischemic attacks. There was no significant difference with respect to either onset or duration of delirium among the 3 groups. Median length of hospital stay and in-hospital mortality were similar among the 3 groups.

CONCLUSIONS

Delirium rates after vascular surgery were similar with local, regional, or general anesthesia techniques. The presence of risk factors for the development of postoperative delirium should not influence the type of anesthesia provided.

Special anesthetic consideration for the patient with a fragility fracture

In this article, an overview is presented of perioperative management of the patient with a fragility fracture, including preoperative risk stratification and optimization, anesthesia risks, anesthesia options, and postoperative pain management. Issues of preoperative evaluation that are of concern for the anesthesiologist because of their direct effect on intraoperative care are discussed. A team interdisciplinary approach and good communication between specialties involved in care of elderly surgical patients is important for optimal patient outcomes and to avoid perioperative complications. Cooperation between anesthesiology and medicine is indispensable in reaching a reasonable consensus regarding preoperative evaluation and should occur on a case-by-case basis.

[Orthogeriatric activity in public hospitals of Castilla y León: description and review of the literature]

The benefits of the collaboration between orthopaedics and geriatrics in the management and care of elderly patients admitted with hip fracture have been widely demonstrated. A questionnaire was sent to all hospital geriatricians of Castilla y León in order to determine the characteristics this collaboration between orthopaedics and geriatrics in the public hospitals of Castilla y León. They were asked about the type of collaboration with orthopaedics in the care of the elderly patient admitted with hip fracture and details of the treatment of the complications. Most of the hospitals maintain a high level of orthogeriatric collaboration with geriatricians, and the geriatrician attends to most of the medical complications of these patients. The average hospital stay is 10 days, with a surgical delay of 3 days. Management of the most frequent clinical problems in hospitals of Castilla y León are detailed in this article, comparing them with the latest articles and current recommendations from clinical practice guides.

Should general anaesthesia be avoided in the elderly?

Surgery and anaesthesia exert comparatively greater adverse effects on the elderly than on the younger brain, manifest by the higher prevalence of postoperative delirium and cognitive dysfunction. Postoperative delirium and cognitive dysfunction delay rehabilitation, and are associated with increases in morbidity and mortality among elderly surgical patients. We review the aetiology of postoperative delirium and cognitive dysfunction in the elderly with a particular focus on anaesthesia and sedation, discuss methods of diagnosing and monitoring postoperative cognitive decline, and describe the treatment strategies by which such decline may be prevented.

Perioperative delirium and its relationship to dementia

A number of serious clinical cognitive syndromes occur following surgery and anesthesia. Postoperative delirium is a behavioral syndrome that occurs in the perioperative period. It is diagnosed through observation and characterized by a fluctuating loss of orientation and confusion. A distinct syndrome that requires formalized neurocognitive testing is frequently referred to as postoperative cognitive dysfunction (POCD). There are serious concerns as to whether either postoperative delirium or postoperative cognitive dysfunction leads to dementia. These concerns are reviewed in this article.

Accuracy of regional cerebral oxygen saturation in predicting postoperative cognitive dysfunction after total hip arthroplasty: regional cerebral oxygen saturation predicts POCD

To estimate the accuracy of regional cerebral oxygen saturation (rSO(2)) in predicting postoperative cognitive dysfunction (POCD) for patients undergoing total hip arthroplasty, 46 patients aged more than 50years old were enrolled. We measured the patients' cognitive function by using a battery of six neuropsychological tests before surgery and then 7days after surgery again. rSO(2) was continuously monitored by near-infrared spectroscopy during surgery. POCD was present in 9 (19.6%) patients 1week after surgery. Logistic regression analysis showed that increasing age [OR=1.224, P=0.035] and maximum percentage drop in rSO(2) (rSO(2%max)) [OR=1.618, P=0.011] were significant risk factors for POCD. The area under the receiver operating characteristic curve of rSO(2%max) was 0.833 [95% confidence interval (CI) 0.615-1.051] at cutoff value of 11%. The specificity and sensitivity of rSO(2%max) >11% in predicting POCD were 77.8% and 86.5%, respectively. rSO(2%max) more than 11% was a potential predictor for POCD.

Surgical trauma induces iron accumulation and oxidative stress in a rodent model of postoperative cognitive dysfunction

Postoperative cognitive dysfunction (POCD) is recognized as a complication after surgery in the elderly. The exact pathogenic mechanisms of POCD are still unknown. In this study, we investigated the role of iron accumulation within the central nervous system in the development of cognitive dysfunction in rats following splenectomy. Cognitive function was assessed using a Morris water maze on postoperative days 1, 3, and 7. Impaired cognitive function was observed on days 1 and 3 after splenectomy, while an anesthesia-alone group showed no significant difference from the control. Serum iron levels decreased and brain iron content increased on days 1 and 3 after surgery, which was in parallel with the impairment of cognitive function. Furthermore, the levels of proteins involved in the maintenance of brain iron homeostasis, including ferritin, transferrin receptor 1, and iron regulatory protein 2, were significantly different at postoperative days 1 and 3 in the hippocampus of splenectomized animals when compared with those of the control. The alterations in iron homeostasis were accompanied by intensified oxidative stress as measured by increases in the lipid peroxidation product, malondialdehyde, and a decrease in the levels of superoxide dismutase activity. Overall, these findings suggest that the impaired cognitive function was primarily due to surgical trauma rather than anesthesia. Increased iron accumulation and oxidative stress in the brain, especially in the hippocampus, may be involved in the pathogenesis of POCD.

Perioperative inflammatory response and protein S-100β concentrations - relationship with post-operative cognitive dysfunction in elderly patients

BACKGROUND

One major concern in about one third of elder patients after total hip-replacement surgery is post-operative cognitive dysfunction (POCD). Previous studies have suggested that cognitive impairment is accompanied with changes in serum S-100β protein (S-100β) and inflammatory markers. Thus, the aim of the current study was to investigate the value of serum S-100β and interleukin(IL)-1β, IL-6, tumour necrosis factor-α (TNF-α), and C-reactive protein (CRP) in reflecting POCD after total hip-replacement surgery.

METHODS

Forty-two elderly patients were enrolled, and 37 patients completed the follow-up. Serum S-100β protein and IL-1β, IL-6, TNF-α, and CRP were determined pre-operatively, as well as 1 h and 6 h post-operatively. Neuropsychological tests were performed pre-operatively, as well as on day 1, 3, and 7 post-operatively.

RESULTS

Seventeen (45.9%, 17/37) patients developed POCD 1 day after surgery, and three (8.1%, 3/37) developed POCD 7 days after surgery. [Correction added after publication 7 February 2012: in the preceding sentence (54.1%, 17/37) was corrected to (45.9%, 17/37)]. Patients with POCD 1 day after surgery had significantly higher serum levels of IL-6 at 6 h (135 ± 32 pg/ml vs. 91 ± 29 pg/ml, P < 0.05) and S-100β at 1 h (1872 ± 385 pg/ml vs. 1289 ± 143 pg/ml, P < 0.05. No significant post-operative change was detected in levels of TNF-α, IL-1, or CRP.

CONCLUSION

The serum levels of pro-inflammatory marker IL-6 and S-100β protein increased after total hip-replacement in elderly patients, and such increase may serve as predicting parameters for the occurrence of POCD.

Can postoperative cognitive dysfunction be avoided?

Postoperative cognitive dysfunction (POCD) refers to a postoperative decline in cognitive function compared with preoperative cognitive function. Diagnosis requires pre- and postoperative testing, the latter of which is usually performed both 7 days and 3 months postoperatively. Although several risk factors for POCD have been described, age is the only consistently reported risk factor. Postoperative cognitive dysfunction is often transient. It may last several months, and is associated with leaving the labor market prematurely and increased mortality. As the pathophysiology of POCD is still a matter of debate and is likely to be multifactorial, there are no widely accepted prophylactic and therapeutic interventions. In this article, we discuss POCD's definition, risk factors, long-term significance, and pathophysiology. We also present data on prophylactic interventions that have been investigated in clinical trials.

Exposure to general anesthesia and risk of Alzheimer's disease: a systematic review and meta-analysis

BACKGROUND

Alzheimer's disease (AD) is common among older adults and leads to significant disability. Volatile anesthetic gases administered during general anesthesia (GA) have been hypothesized to be a risk factor for the development of AD. The objective of this study is to systematically review the association between exposure to GA and risk of AD.

METHODS

We searched electronic databases including MEDLINE, Embase, and Google scholar for observational studies examining the association between exposure to GA and risk of AD. We examined study quality using a modified version of the Newcastle-Ottawa risk of bias assessment for observational studies. We used standard meta-analytic techniques to estimate pooled odds ratios (OR) and 95% confidence intervals (CI). Subgroup and sensitivity analyses were undertaken to evaluate the robustness of the findings.

RESULTS

A total of 15 case-control studies were included in the review. No cohort studies were identified that met inclusion criteria. There was variation in the methodological quality of included studies. There was no significant association between any exposure to GA and risk of AD (pooled OR: 1.05; 95% CI: 0.93 - 1.19, Z = 0.80, p = 0.43). There was also no significant association between GA and risk of AD in several subgroup and sensitivity analyses.

CONCLUSIONS

A history of exposure to GA is not associated with an increased risk of AD although there are few high-quality studies in this area. Prospective cohort studies with long-term follow-up or randomized controlled trials are required to further understand the association between GA and AD.

General anaesthesia does not contribute to long-term post-operative cognitive dysfunction in adults: A meta-analysis

CONTEXT

The contribution of anaesthesia itself to post-operative cognitive dysfunction (POCD) or the potential protective effect of one specific type of anaesthesia on the occurrence of POCD is unclear.

AIMS

This is a meta-analysis evaluating the effects of the anaesthetic technique (regional vs. general anaesthesia) on POCD of patients undergoing non-cardiac surgery.

SETTINGS AND DESIGN

Meta-analysis performed in a University affiliated hospital.

METHODS

A search for randomized controlled trials (RCT) comparing regional anaesthesia to general anaesthesia for surgery was done in PUBMED, MEDLINE, EMBASE, EBM Reviews-Cochrane Central Register of Controlled Trials, PsychINFO and Current Contents/all editions in 2009.

STATISTICAL ANALYSIS

Data were analyzed with comprehensive Meta-analysis Version 2.2.044.

RESULTS

Twenty-six RCTs including 2365 patients: 1169 for regional anaesthesia and 1196 for general anaesthesia were retained. The standardized difference in means for the tests included in the 26 RCTs was -0.08 (95% confidence interval: -0.17-0.01; P value 0.094; I-squared = 0.00%). The assessor was blinded to the anaesthetic technique for 12 of the RCTs including only 798 patients: 393 for regional anaesthesia and 405 for general anaesthesia. The standardized difference in means for these 12 studies is 0.05 (-0.10-0.20; P=0.51; I-squared = 0.00%).

CONCLUSIONS

The present meta-analysis does not support the concerns that a single exposure to general anaesthesia in an adult would significantly contribute to permanent POCD after non-cardiac surgery.

Pervasive cognitive impairment in acute rehabilitation inpatients without brain injury

OBJECTIVE

To establish feasibility for the hypothesis that patients in acute rehabilitation who are hospitalized for disorders not known to involve cerebral injury can have significant cognitive impairment.

DESIGN

A comparison of performances on neuropsychological tests between 2 samples of subjects: inpatients in an acute rehabilitation hospital without known cerebral disease and normal community-dwelling persons.

SETTING

Acute inpatient rehabilitation hospital.

PATIENTS AND PARTICIPANTS

Nineteen hospitalized patients without delirium who were screened for pre-existing cerebral and psychiatric illness, dementia, and dependency in basic self-care skills before hospitalization. Eighteen community-dwelling persons who were not different in terms of age and education served as the control group.

METHODS

Participants completed 10 commonly used neuropsychological tests of executive, language, and memory functions. Data were analyzed by using multivariate analysis of variance.

MAIN OUTCOME MEASUREMENTS

Raw scores on the 10 neuropsychological tests.

RESULTS

Hospitalized patients performed significantly worse on 9 of 10 tests than community-dwelling participants. Older hospitalized participants had significantly greater cognitive impairment than younger hospitalized participants, which suggested increased susceptibility to effects of hospitalization on cognition.

CONCLUSIONS

Patients hospitalized without brain injury, and especially elderly patients, should be carefully monitored for cognitive deficits that may affect posthospitalization quality of living. Further research is needed to determine whether the cognitive deficits in such patients persist after discharge and affect functional independence, and to identify mechanisms for the deficits. Furthermore, the use of hospitalized participants without brain injury as control subjects in neuropsychological studies of brain injury should be balanced with an additional comparison group of matched, neurologically healthy, normal subjects who live in the community to control for cognitive impairments that are associated with acute hospitalization.

Intraoperative warming and post-operative cognitive dysfunction after total knee replacement

BACKGROUND

Post-operative cognitive dysfunction (POCD) can affect 30% of orthopedic surgery patients. We hypothesized that perioperative temperature has an impact on POCD.

METHODS

We included 150 patients over 65 years of age scheduled for total knee replacement under spinal anesthesia. They were randomized to receive standard care (sheet cover) or active warming. Neurocognitive assessment (11 subtests) was performed pre-operatively and at day 4 (three subtests) and 3 months (10 subtests). A control group of 55 nonsurgical patients took the same tests at equivalent times. POCD was defined as an individual score decrease of more than 2 standard deviations (SDs) below the baseline on at least two subtests or 2 SDs in the combined z-score, in both cases using control-adjusted changes.

RESULTS

Tympanic temperature declined below 35 °C in 88% of standard-care patients; 25.3% of warmed patients had a temperature ≥36 °C. On day 4, 3.2% of standard-care patients and 19.4% of warmed patients had POCD (P=0.0058). At 3 months, there were no between-group differences (standard care, 14.3%; warmed, 6.5%) (P=0.2440).

CONCLUSIONS

Perioperative warming was associated with a higher incidence of cognitive dysfunction at 4 days after total knee replacement in patients >65 years of age.