Postoperative delirium in elderly patients after elective hip or knee arthroplasty performed under regional anesthesia

Incidence of postoperative delirium in older adults undergoing surgical procedures: A systematic literature review and meta-analysis

BACKGROUND

With the increase in life expectancy around the globe, the incidence of postoperative delirium (POD) among older people (≥65 years) is growing. Previous studies showed a wide variation in the incidence of POD, from 4% to 53%, with a lack of specific evidence about the incidence of POD by specific surgery type among older people. The aim of this systematic review and meta-analysis was to determine the incidence of POD by surgery type within populations 65 years and over.

METHODS

Databases including PubMed, Cochrane library, Embase, and CINAHL were searched until October 2020. Due to the relatively higher number of meta-analyses undertaken in this area of research, a streamlined systematic meta-analysis was proposed.

RESULTS

A total of 28 meta-analyses (comprising 284 individual studies) were reviewed. Data from relevant individual studies (n = 90) were extracted and included in the current study. Studies were grouped into eight surgery types and the incidence of POD for orthopedic, vascular, spinal, cardiac, colorectal, abdominal, urologic, and mixed surgeries was 20%, 14%, 13%, 32%, 14%, 30%, 10%, and 26%, respectively. POD detection instruments were different across the studies, with Confusion Assessment Method (CAM & CAM-ICU) being the most frequently adopted.

LINKING EVIDENCE TO ACTION

This study showed that POD incidence in older people undergoing surgery varied widely across surgery type. The more complex surgeries like cardiac and abdominal surgeries were associated with a higher risk of POD. This highlights the need to include the level of surgery complexity as a risk factor in preoperative assessments.

Postoperative Delirium after Dexmedetomidine versus Propofol Sedation in Healthy Older Adults Undergoing Orthopedic Lower Limb Surgery with Spinal Anesthesia: A Randomized Controlled Trial

BACKGROUND

Delirium is a critical postoperative complication in older patients. Based on the hypothesis that intraoperative dexmedetomidine sedation would lower postoperative delirium than propofol sedation would, the authors compared the incidence of postoperative delirium in older adults, using the mentioned sedatives.

METHODS

This double-blinded, randomized controlled study included 748 patients, aged 65 yr or older, who were scheduled for elective lower extremity orthopedic surgery, between June 2017 and October 2021. Patients were randomized equally into two groups in a 1:1 ratio according to the intraoperative sedative used (dexmedetomidine vs. propofol). The postoperative delirium incidence was considered the primary outcome measure; it was determined using the confusion assessment method, on the first three postoperative days. The mean arterial pressure and heart rate were evaluated as secondary outcomes.

RESULTS

The authors enrolled 732 patients in the intention-to-treat analyses. The delirium incidence was lower in the dexmedetomidine group than in the propofol group (11 [3.0%] vs. 24 [6.6%]; odds ratio, 0.42; 95% CI, 0.201 to 0.86; P = 0.036). During sedation, the mean arterial pressure (median [interquartile range] mmHg) was higher in the dexmedetomidine group (77 [71 to 84]) than in the propofol group (74 [69 to 79]; P < 0.001); however, it significantly fell lower (74 [68 to 80]) than that of the propofol group (80 [74 to 87]) in the postanesthesia care unit (P < 0.001). Lower heart rates (beats/min) were recorded with the use of dexmedetomidine than with propofol, both during sedation (60 [55 to 66] vs. 63 [58 to 70]) and in the postanesthesia care unit (64 [58 to 72] vs. 68 [62-77]; P < 0.001).

CONCLUSIONS

Dexmedetomidine showed a lower incidence of postoperative delirium than propofol in healthy older adults undergoing lower extremity orthopedic surgery.

EDITOR’S PERSPECTIVE

Postoperative Delirium and Postoperative Cognitive Dysfunction in Patients with Elective Hip or Knee Arthroplasty: A Narrative Review of the Literature

Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are common complications following total knee arthroplasty (TKA) and total hip arthroplasty (THA), affecting the length of hospital stay and increasing medical complications. Although many papers have been published on both conditions in this setting, no reviews have currently been written. Thus, the purpose of our study is to summarize the current literature and provide information about POD and POCD following elective THA or TKA. Our literature search was conducted in the electronic databases PubMed and the Cochrane library. We found that POD is a common complication following elective THA or TKA, with a median incidence of 14.8%. Major risk factors include older age, cognitive impairment, dementia, preoperative (pre-op) comorbidities, substance abuse, and surgery for fracture. Diagnosis can be achieved using tools such as the confusion assessment method (CAM), which is sensitive, specific, reliable, and easy to use, for the identification of POD. Treatment consists of risk stratification and the implementation of a multiple component prevention protocol. POCD has a median incidence of 19.3% at 1 week, and 10% at 3 months. Risk factors include older age, high BMI, and cognitive impairment. Treatment consists of reversing risk factors and implementing protocols in order to preserve physiological stability. POD and POCD are common and preventable complications following TKA and THA. Risk stratification and specific interventions can lower the incidence of both syndromes. Every physician involved in the care of such patients should be informed on every aspect of these conditions in order to provide the best care for their patients.

5-HT3 receptor antagonists decrease the prevalence of postoperative delirium in older patients undergoing orthopedic lower limb surgery

BACKGROUND

Delirium is an important postoperative complication. Recent research suggested that 5-hydroxytryptamine 3 (5-HT₃) receptor antagonists may have clinical effect in the treatment and prevention of delirium. We investigated the association between 5-HT₃ receptor antagonists and the occurrence of postoperative delirium (POD).

METHODS

Retrospectively, the electronic medical records were reviewed in patients aged ≥ 65 years who underwent orthopedic lower limb surgery under regional anesthesia (spinal or combined spinal-epidural anesthesia) and administered intravenous 0.075 mg palonosetron or 0.3 mg ramosetron prior to the end of surgery between July 2012 and September 2015. POD incidence and anesthesia-, surgery-, and patient-related factors were evaluated. To investigate the association between 5-HT₃ receptor antagonists and the occurrence of POD, multivariable logistic regression analysis was performed.

RESULTS

Of the 855 patients included, 710 (83%) were administered 5-HT₃ receptor antagonists. POD was confirmed in 46 (5.4%) patients. 5-HT₃ receptor antagonists reduced the POD incidence by 63% (odds ratio [OR] 0.37; 95% confidence interval [CI], 0.15-0.94; P = 0.04). Moreover, the POD incidence decreased by 72% (OR 0.28, 95% CI 0.10-0.77, P = 0.01) when palonosetron was administered. Other identified risk factors for POD were emergency surgery, older age, hip surgery, lower body mass index, and intraoperative propofol sedation.

CONCLUSION

5-HT₃ receptor antagonists may be related with a significantly reduced risk for POD in older patients undergoing orthopedic lower limb surgery. Notably, palonosetron was more effective for POD prevention.

Postoperative delirium following total joint arthroplasties in a multi-ethnic population - A prospective observational study

BACKGROUND

Postoperative delirium (POD) is a cause of poorer patient outcomes following total joint arthroplasties (TJA). However, it often goes undiagnosed. Although various risk factors have been documented, study heterogeneity leads to poor understanding within a South East Asian population. This study aims to evaluate POD within this demographic and elucidate its risk factors.

METHODS

This was a single-centre prospective observational study comprising 462 patients. Inclusion criteria was patients 65-90 years old undergoing elective TJA. Exclusion criteria was patients unable to personally provide consent for TJA. Preoperative, intraoperative, and postoperative data was recorded to analyse treatment pathway factors. Patients were assessed for POD twice daily for 3 days after TJA using the Confusion Assessment Method (CAM).

RESULTS

Mean age of the study cohort was 72 ± 5 years; 70.1% were female; and mean MMSE score preoperatively was 27.3 ± 3.3. 419 patients underwent total knee arthroplasty (TKA) and 43 patients underwent total hip arthroplasty (THA). 164 patients received general anaesthesia, and 298 patients received regional anaesthesia. Overall, 0% (0/462) of patients tested positive for POD at any postoperative timepoint. While various CAM components were met, no patients were positive for the complete requisite criteria for POD diagnosis.

CONCLUSION

We report zero incidence of POD in 462 patients who underwent elective TJA in our institution. We believe that our streamlined care process including pre-operative assessment, patient-specific anaesthesia regime as well as a strictly administered inpatient clinical care pathway with opioid-reducing strategy and early mobilization are protective factors against POD.

Perioperative Pain Management and Opioid Stewardship: A Practical Guide

Surgical procedures are key drivers of pain development and opioid utilization globally. Various organizations have generated guidance on postoperative pain management, enhanced recovery strategies, multimodal analgesic and anesthetic techniques, and postoperative opioid prescribing. Still, comprehensive integration of these recommendations into standard practice at the institutional level remains elusive, and persistent postoperative pain and opioid use pose significant societal burdens. The multitude of guidance publications, many different healthcare providers involved in executing them, evolution of surgical technique, and complexities of perioperative care transitions all represent challenges to process improvement. This review seeks to summarize and integrate key recommendations into a "roadmap" for institutional adoption of perioperative analgesic and opioid optimization strategies. We present a brief review of applicable statistics and definitions as impetus for prioritizing both analgesia and opioid exposure in surgical quality improvement. We then review recommended modalities at each phase of perioperative care. We showcase the value of interprofessional collaboration in implementing and sustaining perioperative performance measures related to pain management and analgesic exposure, including those from the patient perspective. Surgery centers across the globe should adopt an integrated, collaborative approach to the twin goals of optimal pain management and opioid stewardship across the care continuum.

The Association between Reasons for a Rapid Response Team Alert and Immediate Patient Management in Total Hip Arthroplasty Patients

BACKGROUND

The purpose of this study is to evaluate the value and efficacy of rapid response teams (RRTs) for different triggering events in total hip arthroplasty (THA) patients.

METHODS

A retrospective review of all RRT events at a single, tertiary referral center from 2014 to 2016 was performed. Inclusion criteria were defined as patients >18 years old that underwent primary or revision THA. Information queried included demographics, primary reason for RRT, Charlson Comorbidity Index (CCI), underlying etiology, whether any changes in management occurred, and whether the patient was uptriaged.

RESULTS

In total, 168 RRTs were called on 153 hip arthroplasty patients (mean age 65.2 ± 14.1 years; mean body mass index 32.3 ± 4.8, 66% female). Length of stay in RRT for primary and revision THA was 3.4 and 6.2 days, respectively. This was significantly longer than the length of stay for primary THA patients (2.4 days, P < .001) and revision THA patients (4.6 days, P = .005) that did not require an RRT. There were no mortalities. RRTs for hypotension/presyncope (11%) and for syncope (11%) resulted in significantly fewer changes in management (P < .01) than tachycardia (77%), hypoxia (57%), AMS (79%), and other (47%). RRTs for hypotension/presyncope (28%), syncope (15%), and hypoxia (30%) resulted in significantly fewer patients being uptriaged (P < .001) than tachycardia (81%). Hypotension/presyncope was found to be significantly more commonly due to volume depletion (67%) (P < .001) than other etiologies. Hypoxia was significantly more commonly due to atelectasis (57%) and opioids/oversedation (30.4%) (P = .037). AMS/delirium was also significantly more commonly caused by opioids/over-sedation (71%) (P < .001).

CONCLUSION

In patients undergoing THA, RRTs for hypotension/presyncopal symptoms and syncope were significantly less likely to result in changes in management or uptriaging compared to tachycardia. The most common etiologies were potentially preventable, including volume depletion and opioid use.

Preoperative Cognitive Assessment Recommendations for the Older Adult

PURPOSE

The purpose of this project was to identify the need for and to improve the preoperative cognitive assessment of the older adult.

DESIGN

A retrospective chart review was used to explore the incidence of postoperative delirium (PD) and characteristics associated with it.

METHODS

A retrospective chart review was used to identify the incidence of PD in a community hospital. The data were analyzed using descriptive statistics for trends in demographic and physiological characteristics of older adults undergoing elective hip or knee surgery.

FINDINGS

The incidence of PD was found to be 11%. Older adults with PD had an increased mean age and comorbid conditions. PD was associated with a mean increase in hospital stay, postoperative complications, and 30-day readmission.

CONCLUSIONS

Preoperative cognitive assessment can identify high-risk patients, stratify care, medically optimize the older adult before surgery, and improve perioperative outcomes.

Pre-operative hemoglobin level and use of sedative-hypnotics are independent risk factors for post-operative delirium following total knee arthroplasty

BACKGROUND

Delirium is a well-known complication following surgery, especially with the increasing age of patients undergoing surgery. The increasing demands resulting from a prolonged healthy life expectancy has resulted in more arthroplasties despite their age and existing comorbidities. The purpose of this study is to explore the various risk factors that may contribute to delirium in unilateral and bilateral total knee arthroplasties in the elderly population.

METHODS

170 patients who underwent unilateral or bilateral total knee arthroplasties were analyzed retrospectively for delirium. Age, sex, comorbidities, use of sedative-hypnotics, peri-operative blood loss, pre- and post-operative laboratory blood test results were investigated and analyzed.

RESULTS

The incidence of post-operative delirium was 6.5% (11 out of 170 patients) with a mean age of 79.5 (± 6.9) years, compared to 73.0 (± 9.0) years in the non-delirium group. Higher age, use of sedative-hypnotics, low pre-operative Hb and Ht, low post-operative Hb, Ht and BUN were observed in the delirium group. Multivariate logistic regression analysis identified that the use of sedative-hypnotics and pre-operative Hb level were independent risk factors for post-operative delirium after TKA. The odds ratios for the use of sedative-hypnotics and pre-operative Hb level were 4.6 and 0.53, respectively. Receiver operating characteristic curve analysis showed that pre-operative Hb of less than 11.1 g/dL was a predictor for the development of delirium, with a sensitivity of 54.6% and a specificity of 91.6%.

CONCLUSION

Patients with a pre-operative Hb level of < 11.1 g/dL or those using sedative-hypnotics are associated with post-operative delirium. Peri-operative management and preventative measures are therefore needed to reduce the risks of post-operative delirium in such patients.

Postoperative Serum Albumin Decrease Independently Predicts Delirium in the Elderly Subjects after Total Joint Arthroplasty

Background:

Postoperative delirium (POD), a neurobehavioral syndrome induced by dysfunction of neural activity, is a common and serious complication. This current study aimed to investigate independent predictors for POD in elderly subjects after total joint arthroplasty (TJA).

Methods:

Eligible elderly patients (≥65 years) who underwent elective unilateral primary hip or knee arthroplasty under epidural anesthesia from October 2016 to January 2019 were consecutively enrolled. POD was diagnosed following the guidance of the 5th edition of Diagnostic and Statistical Manual of Mental Disorders, (DSM V, 2013). The relative change in serum Alb (ΔAlb) was defined as the absolute value of (preoperative Alb value– nadir value within postoperative day 2)/preoperative Alb ×100%. The predictive value of ΔAlb for POD was evaluated by receiver operating characteristic (ROC) curve analysis. Univariate and multivariate logistic regression analyses were used for evaluating risk factors for POD.

Results:

A total of 328 patients were enrolled in the analysis, of which 68 (20.7%, 68/328) patients developed POD within postoperative 7 days. ΔAlb was an effective predictor for POD with an area under the curve (AUC) of 0.821, a sensitivity of 76.15% and a specificity of 70.59%, respectively (P<0.001). Univariate and multivariate logistic regression analyses indicated that ΔAlb was the only independent risk factor for POD (OR: 2.43, 95%CI: 1.17–4.86, P=0.015).

Conclusions:

ΔAlb was an independent risk factor for POD in elderly subjects after TJA.

Intravenous vs Oral Acetaminophen as a Component of Multimodal Analgesia After Total Hip Arthroplasty: A Randomized, Blinded Trial

BACKGROUND

Multimodal analgesia including acetaminophen is increasingly popular for analgesia after total hip arthroplasty (THA). Intravenous (IV) administration of acetaminophen has pharmacokinetic benefits, but unclear clinical advantages. The authors hypothesized that IV acetaminophen would reduce pain with activity, opioid usage, or opioid-related side effects, compared to oral acetaminophen.

METHODS

In this double-blinded, randomized, controlled trial, 154 THA patients received either IV or oral acetaminophen as part of a comprehensive opioid-sparing multimodal analgesia strategy. Primary outcomes were pain with physical therapy on postoperative day (POD) 1, opioid side effects (POD 1), and cumulative opioid use.

RESULTS

There was no difference in opioid side effects, pain scores, or opioid use between the groups.

CONCLUSION

Patients in both groups had low pain scores, minimal opioid side effects, and limited opioid usage (corresponding to 6 doses of tramadol 100 mg over 3 days). This highlights multimodal analgesia as an effective method of pain control for THA.

The Association of Delirium with Perioperative Complications in Primary Elective Total Hip Arthroplasty

Background

Our goal was to determine whether postoperative delirium is associated with inpatient complication rates after primary elective total hip arthroplasty (THA).

Methods

Using the National Inpatient Sample, we analyzed records of patients who underwent primary elective THA from 2000 through 2009 to identify patients with delirium (n = 13,551) and without delirium (n = 1,992,971) and to assess major perioperative complications (acute renal failure, death, myocardial infarction, pneumonia, pulmonary embolism, and stroke) and minor perioperative complications (deep vein thrombosis, dislocation, general procedural complication, hematoma, seroma, and wound infection). Patient age, sex, length of hospital stay, and number of comorbidities were assessed. We used multivariate logistic regression to determine the association of delirium with complication rates (significance, p < 0.01).

Results

Patients with delirium were older (mean, 75 ± 0.2 vs. 65 ± 0.1 years), were more likely to be male (56% vs. 52%), had longer hospital stays (mean, 5.7 ± 0.07 vs. 3.8 ± 0.02 days), and had more comorbidities (mean, 2.8 ± 0.03 vs. 1.4 ± 0.01) (all p < 0.001) versus patients without delirium. Patients with delirium were more likely to have major (11% vs. 3%) and minor (17% vs. 7%) perioperative complications versus patients without delirium (both p < 0.001). When controlling for age, sex, and number of comorbidities, delirium was independently associated with major and minor complications (odds ratio, 2.0; 95% confidence interval, 1.7 to 2.3).

Conclusions

Delirium is an independent risk factor for major and minor perioperative complications after primary elective THA.

Postoperative delirium in elderly patients with critical limb ischemia undergoing major leg amputation: a retrospective study

BACKGROUND

Critical limb ischemia has been identified as a risk factor for the incidence of postoperative delirium in elderly patients. Limb amputation is the last option in critical limb ischemia treatments. We investigated the incidence and predisposing factors of postoperative delirium in patients undergoing major leg amputation.

METHODS

From January 2012 to December 2016, 121 patients aged over 60 years who had undergone major leg amputation were enrolled in this study. Various factors related to the patients' outcomes were assessed, including demographic, preoperative laboratory, anesthetic, surgical, and postoperative indicators.

RESULTS

Twenty two patients were excluded and 99 patients were assigned to either the delirium group or no delirium group. Forty of them (40%) developed a delirium during 30 days postoperatively. Univariate analysis implied that end-stage renal disease on hemodialysis, alcohol consumption, C-reactive protein, staying in an intensive care unit (ICU), duration of an ICU stay, occurrence of complications, and mortality during six months, were the factors that accounted for significant differences between the two groups. In multivariate analysis, three factors were significantly related to the development of delirium: mortality during six months (odds ratio [OR] = 13.86, 95% CI [2.10-31.90]), alcohol (OR = 8.18, 95% CI [1.13-16.60]), and hemodialysis (OR = 4.34, 95% CI [2.06-93.08]).

CONCLUSIONS

Approximately 40% of the elderly patients suffered from postoperative delirium in major leg amputation. Identifying those with risk factors for postoperative delirium and intervening at the early stage will be of great benefit in major leg amputations for the elderly population.

Postoperative delirium in total knee and hip arthroplasty patients: a study of perioperative modifiable risk factors

BACKGROUND

Postoperative delirium continues to pose major clinical difficulties. While unmodifiable factors (e.g. age and comorbidity burden) are commonly studied risk factors for delirium, the role of modifiable factors, such as anaesthesia type and commonly used perioperative medications, remains understudied. This study aims to evaluate the role of modifiable factors for delirium after hip and knee arthroplasties.

METHODS

We performed a retrospective study of 41 766 patients who underwent hip or knee arthroplasties between 2005 and 2014 at a single institution. Data were collected as part of routine patient care. Multivariable logistic regression models assessed associations between anaesthesia type and commonly used perioperative medications (opioids, benzodiazepines, and ketamine) and postoperative delirium. Odds ratios (OR) and 95% confidence intervals (CI) are reported. Various sensitivity analyses are also considered, including multiple imputation methods to address missing data.

RESULTS

Postoperative delirium occurred in 2.21% (n=922) of all patients. While patients who received neuraxial anaesthesia were at lower risk for postoperative delirium (compared with general anaesthesia; epidural OR 0.59 CI 0.38-0.93; spinal OR 0.55 CI 0.37-0.83; combined spinal/epidural OR 0.56 CI 0.40-0.80), those given intraoperative ketamine (OR 1.27 CI 1.01-1.59), opioids (OR 1.25 CI 1.09-1.44), postoperative benzodiazepines (OR 2.47 CI 2.04-2.97), and ketamine infusion (OR 10.59 CI 5.26-19.91) were at a higher risk.

CONCLUSIONS

In this cohort of hip and knee arthroplasty patients, anaesthesia type and perioperative medications were associated with increased odds for postoperative delirium. Our results support the notion that modifiable risk factors may exacerbate or attenuate risk for postoperative delirium.

Incidence of postoperative delirium in patients undergoing total knee arthroplasty-an Asian perspective

BACKGROUND

Very little is known in the literature with regards to the incidence of postoperative delirium following total knee arthroplasty (TKA) in Asians and the associated surgical factors. We conducted a retrospective study on incidence of postoperative delirium following TKA in Asians.

METHODS

One thousand sixteen knees of 954 consecutive patients who underwent TKA by the senior author of this study in the year 2006 were included in this review. All written and electronic medical records for patients were screened. Delirium was recorded to be present based on clinical entry onto the patients' inpatient hospital notes and a diagnosis made by psychiatrist based on the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV). All statistical analysis was performed using SPSS v.18.0 (IBM Corp., Armonk, NY, USA).

RESULTS

The incidence of postoperative delirium in our patients undergoing TKA was 0.59%. Six patients had a confirmed diagnosis of delirium postoperatively. We noted an association between a higher mean age (P<0.0001), a lower body mass index (P<0.0001), Chinese ethnicity (P=0.002), male gender (P=0.002) and chronic opioid use (P<0.0001) with incidence of post-operative delirium. We also noted a higher proportion of post-operative DVT (P<0.0001) and wound infection (P<0.0001) in the delirium group.

CONCLUSIONS

The incidence of postoperative delirium in Asians undergoing TKA in our institution is very low at 0.59%. Advanced age, lower body mass index, Chinese ethnicity, male gender and preoperative chronic opioid use may be associated with developing postoperative delirium.

Prevalence and risk factors for postoperative delirium in total joint arthroplasty patients: A prospective study

BACKGROUND

The aim of this prospective study was to investigate the incidence and clinical features of delirium after total joint arthroplasty, and to establish the potential risk factors for postoperative delirium.

METHODS

A total of 212 consecutive patients undergoing hip or knee arthroplasty, who met the inclusion and exclusive criteria were enrolled. The general characteristics, preoperative and postoperative hematological variables were documented respectively. According to the presence of delirium, all patients were divided into the delirium group and non-delirium group. Univariate and multivariate logistic regression were performed to identify the possible predictors for postoperative delirium.

RESULTS

At a minimum of 6months of follow-up, 35 patients were observed with postoperative delirium at an estimated total incidence of 16.5%. The incidence of delirium was statistically higher in hip arthroplasty (22.8%) than that in knee arthroplasty (7.1%). The multivariate regression analysis identified older age (OR=1.590, P=0.023), a history of stroke (OR=190.23, P=0.036), preoperative PaO₂ (OR=1.277, P=0.018) and equivalent fentanyl dose (OR=1.010, P=0.012) as the predictive factors for postoperative delirium after total joint arthroplasty.

CONCLUSIONS

The incidence of postoperative delirium after total joint arthroplasty is higher than expected. Based on our findings, we suggest that the surgeons should focus on those patients who have these risk factors and ensure the appropriate management to avoid postoperative delirium.

Perioperative Delirium Protocol for the Older Patient

PURPOSE

Delirium is an acute change in cognition and attention. It may affect any age group. It is most common in older patients and is associated with a significant increase in mortality. The purpose of this project was to implement an assessment protocol to identify patients at risk for postoperative delirium.

DESIGN

A case study approach was used.

METHODS

The Confusion Assessment Method (CAM) tool for screening and diagnostic purposes was used to train surgeons, anesthesia providers, and nurses. A standardized delirium assessment and management protocol was developed and implemented.

FINDINGS

The CAM and geriatric preoperative assessment was used with the patient discussed in the case study. The patient did not experience postoperative delirium and was discharged from perioperative services on the same day.

CONCLUSION

Evidence informs us that early recognition and multifaceted interventions can prevent postoperative delirium in the elderly.

Comprehensive geriatric assessment of effects of hospitalization and long-term rehabilitation of patients following lower extremity arthroplasty

[Purpose] This study was performed to examine the effects of subacute physical therapy (PT) on activities of daily living (ADL), quality of life, and geriatric aspects of patients who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA). [Subjects] The subjects were TKA (n=56) and THA (n=39) patients who received PT on the first day of independent ADL (up to 2 weeks) and just prior to discharge (4 weeks). [Methods] The functional independence measure (FIM), grip strength, knee extension strength (KES), timed up and go (TUG) test, mini-mental state examination (MMSE), geriatric depression scale short form (GDS-15), fall efficacy scale (FES), and medical outcome study 8-item short-form health survey (SF-8) were used as outcome measure, and comorbidity involvement was also investigated. [Results] Improvements in FIM, KES, TUG, GDS-15, FES, and SF-8 scores were seen in both groups (effect size, 0.31-0.87). Poor PT effects were found for THA patients aged ≥65 years, for TKA and THA patients with an MMSE score ≤28, and for THA patients with two or more comorbidities. [Conclusion] Positive effects were seen in patients who received PT at 2-4 weeks after surgery. Thus, additional PT for approximately 2 weeks after the beginning of independent ADL may be beneficial.

Dementia With Lew Body: Impacts of Surgery

Patients who have dementia with Lewy bodies (DLB) and undergo surgery may develop aggravated postoperative cognitive dysfunction or postoperative delirium. Many patients with DLB respond poorly to surgery and anesthesia, and their conditions may worsen if they have other medical complications along with dementia. They may also face high risk of prolonged hospital stay, increased medical problems and/or mortality, causing significant physical, psychosocial, and financial burdens on individuals, family members, and society. Anesthesia, pain medications, old age, and surgery-related stresses are usually held responsible for the complications; however, the exact causes are still not fully understood. Literature on surgery-related complications for patients with DLB appears to be inadequate, and hence the topic merits detailed and systematic research. This article reviews postoperative complications and various surgery-related risk factors for DLB in light of other dementias such as Alzheimer's disease, as their neuropathologic features overlap with those of DLB.

Total Joint Arthroplasty in Nonagenarians: What Are the Risks?

With recent increases in life expectancy in the United States, the number of nonagenarians (age 90-99 years) presenting for lower extremity joint arthroplasty (TJA) will likely rise. Utilizing the National Surgical Quality Improvement Program database, we compared 30-day outcomes of TJA between nonagenarians and controls (age <90 years). Nonagenarians had lower mean BMI, no difference in mean number of comorbidities, and shorter mean operation time. Compared to controls, nonagenarians had longer mean length-of-stay, higher readmission rate, and higher risk of postoperative adverse events. Given these findings, orthopaedic surgeons should be aware of the increased risks of TJA in nonagenarians, and should discuss these risks with potential surgical candidates during a shared decision-making process.

Pregabalin and pain after total knee arthroplasty: a double-blind, randomized, placebo-controlled, multidose trial

BACKGROUND

Pregabalin may reduce postoperative pain and opioid use. Higher doses may be more effective, but may cause sedation and confusion. This prospective, randomized, blinded, placebo-controlled study tested the hypothesis that pregabalin reduces pain at 2 weeks after total knee arthroplasty, but increases drowsiness and confusion.

METHODS

Patients (30 per group) received capsules containing pregabalin (0, 50, 100, or 150 mg); two capsules before surgery, one capsule twice a day until postoperative day (POD) 14, one on POD15, and one on POD16. Multimodal analgesia included femoral nerve block, epidural analgesia, oxycodone-paracetamol, and meloxicam. The primary outcome was pain with flexion (POD14).

RESULTS

Pregabalin did not reduce pain at rest, with ambulation, or with flexion at 2 weeks (P=0.69, 0.23, and 0.90, respectively). Pregabalin increased POD1 drowsiness (34.5, 37.9, 55.2, and 58.6% in the 0, 50, 100, and 150 mg arms, respectively; P=0.030), but did not increase confusion (0, 3.5, 0, and 3.5%, respectively; P=0.75). Pregabalin had no effect on acute or chronic pain, opioid consumption, or analgesic side-effects. Pregabalin reduced POD14 patient satisfaction [1-10 scale, median (first quartile, third quartile): 9 (8, 10), 8 (7, 10), 8 (5, 9), and 8 (6, 9.3), respectively; P=0.023). Protocol compliance was 63% by POD14 (50.0, 70.0, 76.7, and 56.7% compliance, respectively), with no effect of dose on compliance. Per-protocol analysis of compliant patients showed no effect of pregabalin on pain scores.

CONCLUSIONS

Pregabalin had no beneficial effects, but increased sedation and decreased patient satisfaction. This study does not support routine perioperative pregabalin for total knee arthroplasty patients.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: http://www.clinicaltrials.gov/ct2/show/study/NCT01333956.

Postoperative Delirium in Patients Undergoing Total Joint Arthroplasty: A Systematic Review

We systematically reviewed the English-language literature to assess the incidence, risk factors and prevention strategies for postoperative delirium following total joint arthroplasty (TJA). A total of 10 studies were included in the final review, of which 3 (30%) were Level I studies, 6 were Level II (60%) studies and 1 (10%) was a Level III study. Incidence of postoperative delirium ranged from 5% to 14.3%. Pre-screening of patients was shown to reduce its incidence. Independent predictors include age, history of psychiatric illness, decreased functional status and decreased verbal memory.

Incidence of delirium following total joint replacement in older adults: a meta-analysis

OBJECTIVE

Delirium is common in older adults following total joint replacement (TJR) of the hip and knee. However, reports of the incidence of delirium vary widely, limiting their usefulness. The current meta-analysis therefore examined (1) the incidence of delirium in older patients who underwent TJR and (2) whether these rates vary according to the (a) joint (hip/knee replacement), (b) inclusion/exclusion of patients who underwent simultaneous bilateral surgery, (c) inclusion/exclusion of patients with preexisting cognitive impairments, (d) type of anesthesia (regional/general), (e) method/frequency of assessment, and (f) postoperative interval.

METHOD

Data from 24 studies (2,895 patients) that measured postsurgical delirium following TJR were analyzed. Mean weighted proportions were calculated using a random-effects model to assess the overall incidence of delirium and whether the rate varied according to the aforementioned variables.

RESULTS

Overall, 17% of patients who underwent TJR developed delirium during hospital admission. Individual estimates varied from 0% to 82%, but this variability was not adequately explained by the variables that were examined.

CONCLUSIONS

Delirium is relatively common following TJR; however, it remains unclear why individual estimates vary so widely. Health professionals working with these patients should remain alert to the presentation, diagnosis and management of delirium to optimize postsurgical outcomes.

Risk factors of delirium in patients undergoing total knee arthroplasty

Although postoperative delirium is a complicated disorder in elderly individuals, no study has been examined the risk factors associated with perioperative comorbidities and clinical laboratory data while specifically focusing on only total knee arthroplasty (TKA). In the present retrospective study, we aimed to evaluate the incidence and perioperative risk factors of postoperative delirium after TKA. Between April 2009 and May 2013, 287 patients (365 knees) aged >65 years who had undergone primary TKA were enrolled. These patients were assigned to the delirium group of 11 patients (11 knees) or the non-delirium group of 276 patients (354 knees). The incidence of delirium among the patients was 3.1% (11/365). Univariate logistic regression analysis indicated that a history of dementia, older age, lower body mass index (BMI) level, and a postoperative day 3 blood urea nitrogen (BUN) level of >14.9 mg/dL were risk factors. However, multivariate logistic regression analysis indicated that a history of dementia (adjusted odds ratio [AOR]: 10.4, [1.09, 100]), older age (AOR: 1.15, [1.01, 1.31]), and a postoperative day 3 BUN level of >14.9 mg/dL (AOR: 4.76, [1.15, 19.7]) were independent risk factors. Based on our findings, we believe that the surgeons should be careful to avoid the postoperative delirium and ensure the appropriate management for patients who have these risk factors.

Thirty-day readmission following total hip and knee arthroplasty - a preliminary single institution predictive model

We sought to identify demographic or care process variables associated with increased 30-day readmission within the total hip and knee arthroplasty patient population. Using this information, we generated a model to predict 30-day readmission risk following total hip and knee arthroplasty procedures. Longer index length of stay, discharge disposition to a nursing facility, blood transfusion, general anesthesia, anemia, anticoagulation status prior to index admission, and Charlson Comorbidity Index greater than 2 were identified as independent risk factors for readmission. Care process factors during the hospital stay appear to have a large predictive value for 30-day readmission. Specific comorbidities and patient demographic factors showed less significance. The predictive nomogram constructed for primary total joint readmission had a bootstrap-corrected concordance statistic of 0.76.

Preoperative cerebrospinal fluid β-Amyloid/Tau ratio and postoperative delirium

Objective

The neuropathogenesis of postoperative delirium remains unknown. Low cerebrospinal fluid (CSF) β-amyloid protein (Aβ) and high CSF Tau levels are associated with Alzheimer's disease. We, therefore, assessed whether lower preoperative CSF Aβ/Tau ratio was associated with higher incidence and greater severity of postoperative delirium.

Methods

One hundred and fifty-three participants (71 ± 5 years, 53% men) who had total hip/knee replacement under spinal anesthesia were enrolled. CSF was obtained during initiation of spinal anesthesia. The incidence and severity of postoperative delirium were determined by Confusion Assessment Method (CAM) and Memorial Delirium Assessment Scale (MDAS) on postoperative day 1 and 2. Aβ40, Aβ42, and Tau levels in the CSF were measured by enzyme-linked immunosorbent assay. The relationships among these variables were determined, adjusting for age and gender.

Results

Participants in the lowest quartile of preoperative CSF Aβ40/Tau and Aβ42/Tau ratio had higher incidence (32% vs. 17%, P = 0.0482) and greater symptom severity of postoperative delirium (Aβ40/Tau ratio: 4 vs. 3, P = 0.034; Aβ42/Tau ratio: 4 vs. 3, P = 0.062, the median of the highest MDAS score) as compared to the combination of the rest of the quartiles. The preoperative CSF Aβ40/Tau or Aβ42/Tau ratio was inversely associated with MDAS score (Aβ40/Tau ratio: −0.12 ± 0.05, P = 0.014, adj. −0.12 ± 0.05, P = 0.018; Aβ42/Tau ratio: −0.65 ± 0.26, P = 0.013, adj. −0.62 ± 0.27, P = 0.022).

Interpretation

Lower CSF Aβ/Tau ratio could be associated with postoperative delirium, pending confirmation of our preliminary results in further studies. These findings suggest potential roles of Aβ and/or Tau in postoperative delirium neuropathogenesis.