Leg Length Discrepancy After Hip Fracture Repair is Associated With Reduced Gait Speed

Introduction

A negative correlation exists between functional outcomes and leg length discrepancy (LLD) following hip fracture repair. We have assessed the effects of LLD following hip fracture repair in elderly patients on 3-meter walking time, standing time, activities of daily living (ADL), and instrumental activities of daily living (IADL).

Methods

One hundred sixty-nine patients enrolled in the STRIDE trial were identified with femoral neck, intertrochanteric, and subtrochanteric fractures that were treated with partial hip replacement, total hip replacement, cannulated screws, or intramedullary nail. Baseline patient characteristics recorded included age, sex, body mass index Charlson comorbidity index (CCI) score. ADL, IADL, grip strength, sit-to-stand time, 3-meter walking time and return to ambulation status were measured at 1 year after surgery. LLD was measured on final follow-up radiographs by either the sliding screw telescoping distance or the difference from a trans-ischial line to the lesser trochanters, and was analyzed as a continuous variable using regression analysis.

Results

Eighty eight patients (52%) had LLD <5 mm, 55 (33%) between 5-10 mm and 26 subjects (15%) >10 mm. Age, sex, BMI, Charlson score, and ambulation status had no significant impact on LLD occurrence. Type of procedure and fracture type did not correlate with severity of LLD. Having a larger LLD was not found to have a significant impact on post-operative ADL (P = .60), IADL (P = .08), sit-to-stand time (P = .90), grip strength (P = .14) and return to former ambulation status (P = .60), but did have a statistically significant impact on 3-meter walking time (P = .006).

Discussion

LLD after hip fracture was associated with reduced gait speed but did not affect many parameters associated with recovery. Continued efforts to restore leg length after hip fracture repair are likely to be beneficial.

Delirium detection methodologies: Implications for outcome measurement in clinical trials in postoperative delirium

OBJECTIVE

Delirium is a common postoperative complication of hip fracture. Various methods exist to detect delirium as a reference standard. The goal of this study was to characterize the properties of the measures obtained in a randomized controlled trial, to document their relationship to the Diagnostic and Statistical Manual of Mental Disorders:Text Revision based diagnosis of postoperative delirium by a consensus panel, and to describe the method in detail to allow replication by others.

METHODS

A secondary analysis of the randomized trial STRIDE (A Strategy to Reduce the Incidence of Postoperative Delirium in Elderly Patients) was conducted. Delirium assessments were performed in 200 consecutive hip fracture repair patients ≥65 years old. Assessors underwent extensive training in delirium assessment and the final delirium diagnosis was adjudicated by a consensus panel of three physicians with expertise in delirium assessment.

RESULTS

A total of 680 consensus panel delirium diagnoses were completed. There were only 19 (2.8%, 19/678) evaluations where the delirium adjudication by the consensus panel differed from delirium findings by the Confusion Assessment Method (CAM). In 16 (84%, 16/19) of the cases, CAM was negative but the consensus panel diagnosed the patient as having delirium based on all of the available information including the CAM.

CONCLUSION

The consensus panel diagnosis was more sensitive compared to CAM alone, however the magnitude of the difference was not large. When assessors are well trained and delirium assessments are closely supervised throughout the study, CAM may be adequate for delirium diagnosis in a clinical trial. Future studies are needed to test this hypothesis.

Processed intraoperative burst suppression and postoperative cognitive dysfunction in a cohort of older noncardiac surgery patients

Postoperative cognitive dysfunction (POCD) is a decline in cognitive test performance which persists months after surgery. There has been great interest in the anesthesia community regarding whether variables generated by commercially available processed EEG monitors originally marketed to prevent awareness under anesthesia can be used to guide intraoperative anesthetic management to prevent POCD. Processed EEG monitors represent an opportunity for anesthesiologists to directly monitor the brain even if they have not been trained to interpret EEG waveforms. There is continued equipoise regarding whether any of the variables generated by the machines' interpretation of raw data are associated with POCD. Most literature has focused on the depth of anesthesia number, however recent studies have shown that processed depth may not be accurate in older age groups due to reduced alpha band power. Burst suppression is an encephalographic pattern of high voltage activity alternating with periods of electrical silence and is another marker of depth which can be obtained from commercial processed EEG monitors. We performed a prospective cohort study to determine whether burst suppression and burst suppression ratio as measured by the BIS Monitor (Bispectral Index, BIS Medtronic, Boulder CO), is associated with cognitive dysfunction 3 months after surgery. We recruited 167 elective surgery patients, 65 years of age and older, anticipated to require at least 2 day inpatient admission. Our main outcome measure was cognitive decline in composite z-score on the Alzheimer's Disease Research Center UDS Battery of at least 1 standard deviation 3 months after surgery relative to preoperative baseline. 14% experienced POCD, this group was older (72 [70, 74] versus 70 [67, 75] years), and had frailty scores as measured by the FRAIL Scale (2 [0, 3] versus 1 [0, 2]) and lower baseline z-scores (- 0.2 [- 0.6, 0.5] versus 0.1 [- 0.3, 0.5]). There was a univariable association between suppression ratio > 10 (SR > 10) and POCD (4.8 [0, 37.3] versus 15.4 [4.0-142.4] min), p = .038. However, after adjustment this relationship did not persist, only anesthetic technique, age, and pain remained in the model. In our cohort of older elective noncardiac surgery patients we found a marginal association between processed burst suppression (total burst suppression p = .067, SR > 5 p = .052, SR > 10.038) which did not persist in a multivariable model. Patients with POCD had almost twice the number of minutes of burst suppression, and three times the amount of time for SR > 5 and > 10. Our finding may be a limitation of the monitor's ability to detect burst suppression. The consistent trend towards more intraoperative burst suppression in patients who developed POCD suggests that future studies are needed to investigate the relationship of raw intraoperative burst suppression and POCD.Trial registry Clinical trial number and registry URL: Optimizing Postoperative Cognitive Dysfunction in the Elderly-PRESERVE, Clinical Trials Gov# NCT02650687; https://clinicaltrials.gov/ct2/show/NCT02650687 .

Association of Depressive Symptoms With Postoperative Delirium and CSF Biomarkers for Alzheimer's Disease Among Hip Fracture Patients

OBJECTIVES

While there is growing evidence of an association between depressive symptoms and postoperative delirium, the underlying pathophysiological mechanisms remain unknown. The goal of this study was to explore the association between depression and postoperative delirium in hip fracture patients, and to examine Alzheimer's disease (AD) pathology as a potential underlying mechanism linking depressive symptoms and delirium.

METHODS

Patients 65 years old or older (N = 199) who were undergoing hip fracture repair and enrolled in the study "A Strategy to Reduce the Incidence of Postoperative Delirium in Elderly Patients" completed the 15-item Geriatric Depression Scale (GDS-15) preoperatively. Cerebrospinal fluid (CSF) was obtained during spinal anesthesia and assayed for amyloid-beta (Aβ) 40, 42, total tau (t-tau), and phosphorylated tau (p-tau)181.

RESULTS

For every one point increase in GDS-15, there was a 13% increase in odds of postoperative delirium, adjusted for baseline cognition (MMSE), age, sex, race, education and CSF AD biomarkers (OR = 1.13, 95%CI = 1.02-1.25). Both CSF Aβ42/t-tau (β = -1.52, 95%CI = -2.1 to -0.05) and Aβ42/p-tau181 (β = -0.29, 95%CI = -0.48 to -0.09) were inversely associated with higher GDS-15 scores, where lower ratios indicate greater AD pathology. In an analysis to identify the strongest predictors of delirium out of 18 variables, GDS-15 had the highest classification accuracy for postoperative delirium and was a stronger predictor of delirium than both cognition and AD biomarkers.

CONCLUSIONS

In older adults undergoing hip fracture repair, depressive symptoms were associated with underlying AD pathology and postoperative delirium. Mild baseline depressive symptoms were the strongest predictor of postoperative delirium, and may represent a dementia prodrome.

The Association of Preoperative Frailty and Postoperative Delirium: A Meta-analysis

BACKGROUND

Both frailty and postoperative delirium (POD) are common in elective surgical patients 65 years of age and older. However, the association between preoperative frailty and POD remains difficult to characterize owing to the large number of frailty and POD assessment tools used in the literature, only a few of which are validated. Furthermore, some validated frailty tools fail to provide clear score cutoffs for distinguishing frail and nonfrail patients. We performed a meta-analysis to estimate the relationship between preoperative frailty and POD.

METHODS

We searched several major databases for articles that investigated the relationship between preoperative frailty and POD in patients with mean age ≥65 years who were undergoing elective, nonemergent inpatient surgery. Inclusion criteria included articles published in English no earlier than 1999. Both preoperative frailty and POD must have been measured with validated tools using clear cutoff scores for frailty and delirium. Articles were selected and data extracted independently by 2 researchers. Risk of bias (ROBINS-I) and presence of confounders were summarized. Odds ratios (ORs) for POD associated with frailty relative to nonfrailty were computed with adjusted ORs when available. Original estimates were pooled by random effects analysis. Statistical significance was set at 2-sided P < .05.

RESULTS

Nine studies qualified for meta-analysis. The Fried score or a modified version of it was used in 5 studies. Frailty prevalence ranged from 18.6% to 56%. Delirium was assessed with the Confusion Assessment Method (CAM) or Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) in 7 studies, Delirium Observation Scale in 1 study, and Intensive Care Delirium Screening Checklist in 1 study. The incidence of POD ranged from 7% to 56%. ROBINS-I risk of bias was low in 1 study, moderate in 4 studies, serious in 3 studies, and critical in 1 study. Random effects analysis (n = 794) of the OR for POD in frail versus nonfrail patients based on adjusted OR estimates was significant with an OR of 2.14 and a 95% confidence interval of 1.43-3.19. The I2 value was in the low range at 5.5, suggesting small variability from random effects. Funnel-plot analysis did not definitively support either the presence or absence of publication bias.

CONCLUSIONS

This meta-analysis provides evidence for a significant association between preoperative frailty and POD in elective surgical patients age 65 years or older.

Effects of Ramelteon on the Prevention of Postoperative Delirium in Older Patients Undergoing Orthopedic Surgery: The RECOVER Randomized Controlled Trial

OBJECTIVES

Postoperative delirium, associated with negative consequences including longer hospital stays and worse cognitive and physical outcomes, is frequently accompanied by sleep-wake disturbance. Our objective was to evaluate the efficacy and short-term safety of ramelteon, a melatonin receptor agonist, for the prevention of postoperative delirium in older patients undergoing orthopedic surgery.

DESIGN

A quadruple-masked randomized placebo-controlled trial (Clinical Trials.gov NCT02324153) conducted from March 2017 to June 2019.

SETTING

Tertiary academic medical center.

PARTICIPANTS

Patients aged 65 years or older, undergoing elective primary or revision hip or knee replacement.

INTERVENTION

Ramelteon (8 mg) or placebo MEASUREMENTS: Eighty participants were randomized to an oral gel cap of ramelteon or placebo for 3 consecutive nights starting the night before surgery. Trained research staff conducted delirium assessments for 3 consecutive days starting on postoperative day (POD) 0, after recovery from anesthesia, and on to POD2. A delirium diagnosis was based upon DSM-5 criteria determined by expert panel consensus.

RESULTS

Of 80 participants, five withdrew consent (one placebo, four ramelteon) and four were excluded (four ramelteon) after randomization. Delirium incidence during the 2 days following surgery was 7% (5 of 71) with no difference between the ramelteon versus placebo: 9% (3 of 33) and 5% (2 of 38), respectively. The adjusted odds ratio for postoperative delirium as a function of assignment to the ramelteon treatment arm was 1.28 (95% confidence interval: 0.21-7.93; z-value 0.27; p-value = 0.79). Adverse events were similar between the two groups.

CONCLUSION

In older patients undergoing elective primary or revision hip or knee replacement, ramelteon was not efficacious in preventing postoperative delirium.

Kidney Function Modifies the Effect of Intraoperative Opioid Dosage on Postoperative Delirium

BACKGROUND

There are few studies demonstrating how kidney function affects the risk of developing delirium in older adult surgical patients administered opioids. This study determined whether baseline kidney function influences the relationship between morphine equivalent dose and the development of delirium on postoperative day (POD) 2 in patients with hip fracture.

METHODS

This retrospective study analyzed emergency department (ED) estimated glomerular filtration rate (eGFR), perioperative serum creatinine, intravenous morphine equivalents, and POD2 delirium assessment by the Confusion Assessment Method in 652 patients aged 65 years or older without preoperative delirium. ED eGFR was used to divide subjects into groups by presence or absence of chronic kidney disease (CKD), and associations of opioid dose with POD2 delirium were compared using multivariable logistic regression.

RESULTS

POD2 delirium incidence was 29.8% (N = 194). Intraoperative and postanesthesia care unit (PACU) morphine equivalent dosage as well as ED eGFR were similar comparing patients with and without POD2 delirium. Age, American Society of Anesthesiologists status, and dementia were associated with delirium on POD2. The odds of POD2 delirium increased significantly with increase of intraoperative opioid in patients with CKD (odds ratio = 1.6; 95% confidence interval = 1.2-2.2), but not in patients without CKD (P-interaction = .04). PACU or POD1 opioid doses were not associated with POD2 delirium after covariate adjustment.

CONCLUSION

This study suggests that incremental increases in intraoperative opioids combined with CKD increase odds of POD2 delirium after hip fracture repair, compared with patients without CKD.

Frailty Is Associated With Postoperative Delirium But Not With Postoperative Cognitive Decline in Older Noncardiac Surgery Patients

BACKGROUND

Postoperative cognitive dysfunction (POCD) and delirium are the most common perioperative cognitive complications in older adults undergoing surgery. A recent study of cardiac surgery patients suggests that physical frailty is a risk factor for both complications. We sought to examine the relationship between preoperative frailty and postoperative delirium and preoperative frailty and POCD after major noncardiac surgery.

METHODS

We performed a prospective cohort study of patients >65 years old having major elective noncardiac surgery with general anesthesia. Exclusion criteria were preexisting dementia, inability to consent, cardiac, intracranial, or emergency surgery. Preoperative frailty was determined using the FRAIL scale, a simple questionnaire that categorizes patients as robust, prefrail, or frail. Delirium was assessed with the Confusion Assessment Method for the intensive care unit (CAM-ICU) twice daily, starting in the recovery room until hospital discharge. All patients were assessed with neuropsychological tests (California Verbal Learning Test II, Trail Making Test, subtests from the Wechsler Adult Intelligence Scale, Logical Memory Story A, Immediate and Delayed Recall, Animal and Vegetable verbal fluency, Boston Naming Test, and the Mini-Mental Status Examination) before surgery and at 3 months afterward.

RESULTS

A total of 178 patients met inclusion criteria; 167 underwent major surgery and 150 were available for follow-up 3 months after surgery. The median age was 70 years old. Thirty-one patients (18.6%) tested as frail, and 72 (43.1%) prefrail before surgery. After adjustment for baseline cognitive score, age, education, surgery duration, American Society of Anesthesiologists (ASA) physical status, type of surgery, and sex, patients who tested frail or prefrail had an estimated 2.7 times the odds of delirium (97.5% confidence interval, 1.0-7.3) when compared to patients who were robust. There was no significant difference between the proportion of POCD between patients who tested as frail, prefrail, or robust.

CONCLUSIONS

After adjustment for baseline cognition, testing as frail or prefrail with the FRAIL scale is associated with increased odds of postoperative delirium, but not POCD after noncardiac surgery.

Shaping anesthetic techniques to reduce post-operative delirium (SHARP) study: a protocol for a prospective pragmatic randomized controlled trial to evaluate spinal anesthesia with targeted sedation compared with general anesthesia in older adults undergoing lumbar spine fusion surgery

BACKGROUND

Postoperative delirium is common in older adults, especially in those patients undergoing spine surgery, in whom it is estimated to occur in > 30% of patients. Although previously thought to be transient, it is now recognized that delirium is associated with both short- and long-term complications. Optimizing the depth of anesthesia may represent a modifiable strategy for delirium prevention. However, previous studies have generally not focused on reducing the depth of anesthesia beyond levels consistent with general anesthesia. Additionally, the results of prior studies have been conflicting. The primary aim of this study is to determine whether reduced depth of anesthesia using spinal anesthesia reduces the incidence of delirium after lumbar fusion surgery compared with general anesthesia.

METHODS

This single-center randomized controlled trial is enrolling 218 older adults undergoing lumbar fusion surgery. Patients are randomized to reduced depth of anesthesia in the context of spinal anesthesia with targeted sedation using processed electroencephalogram monitoring versus general anesthesia without processed electroencephalogram monitoring. All patients are evaluated for delirium using the Confusion Assessment Method for 3 days after surgery or until discharge and undergo assessments of cognition, function, health-related quality of life, and pain at 3- and 12-months after surgery. The primary outcome is any occurrence of delirium. The main secondary outcome is change in the Mini-Mental Status Examination (or telephone equivalent) at 3-months after surgery.

DISCUSSION

Delirium is an important complication after surgery in older adults. The results of this study will examine whether reduced depth of anesthesia using spinal anesthesia with targeted depth of sedation represents a modifiable intervention to reduce the incidence of delirium and other long-term outcomes. The results of this study will be presented at national meetings and published in peer-reviewed journals with the goal of improving perioperative outcomes for older adults.

TRIAL REGISTRATION

Clinicaltrials.gov , NCT03133845. This study was submitted to Clinicaltrials.gov on October 23, 2015; however, it was not formally registered until April 28, 2017 due to formatting requirements from the registry, so the formal registration is retrospective.

Effect of Depth of Sedation in Older Patients Undergoing Hip Fracture Repair on Postoperative Delirium: The STRIDE Randomized Clinical Trial

Importance

Postoperative delirium is the most common complication following major surgery in older patients. Intraoperative sedation levels are a possible modifiable risk factor for postoperative delirium.

Objective

To determine whether limiting sedation levels during spinal anesthesia reduces incident delirium overall.

Design, Setting, and Participants

This double-blind randomized clinical trial (A Strategy to Reduce the Incidence of Postoperative Delirum in Elderly Patients [STRIDE]) was conducted from November 18, 2011, to May 19, 2016, at a single academic medical center and included a consecutive sample of older patients (≥65 years) who were undergoing nonelective hip fracture repair with spinal anesthesia and propofol sedation. Patients were excluded for preoperative delirium or severe dementia. Of 538 hip fractures screened, 225 patients (41.8%) were eligible, 10 (1.9%) declined participation, 15 (2.8%) became ineligible between the time of consent and surgery, and 200 (37.2%) were randomized. The follow-up included postoperative days 1 to 5 or until hospital discharge.

Interventions

Heavier (modified observer's assessment of sedation score of 0-2) or lighter (observer's assessment of sedation score of 3-5) propofol sedation levels intraoperatively.

Main Outcomes and Measures

Delirium on postoperative days 1 to 5 or until hospital discharge determined via consensus panel using Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) criteria. The incidence of delirium was compared between intervention groups with and without stratification by the Charlson comorbidity index (CCI).

Results

Of 200 participants, the mean (SD) age was 82 (8) years, 146 (73%) were women, 194 (97%) were white, and the mean (SD) CCI was 1.5 (1.8). One hundred participants each were randomized to receive lighter sedation levels or heavier sedation levels. A good separation of intraoperative sedation levels was confirmed by multiple indices. The overall incident delirium risk was 36.5% (n = 73) and 39% (n = 39) vs 34% (n = 34) in heavier and lighter sedation groups, respectively (P = .46). Intention-to-treat analyses indicated no statistically significant difference between groups in the risk of incident delirium (log-rank test χ2, 0.46; P = .46). However, in a prespecified subgroup analysis, when stratified by CCI, sedation levels did effect the delirium risk (P for interaction = .04); in low comorbid states (CCI = 0), heavier vs lighter sedation levels doubled the risk of delirium (hazard ratio, 2.3; 95% CI, 1.1- 4.9). The level of sedation did not affect delirium risk with a CCI of more than 0.

Conclusions and Relevance

In the primary analysis, limiting the level of sedation provided no significant benefit in reducing incident delirium. However, in a prespecified subgroup analysis, lighter sedation levels benefitted reducing postoperative delirium for persons with a CCI of 0.

Trial Registration

clinicaltrials.gov Identifier: NCT00590707.

Intraoperative Infusion of Dexmedetomidine for Prevention of Postoperative Delirium and Cognitive Dysfunction in Elderly Patients Undergoing Major Elective Noncardiac Surgery: A Randomized Clinical Trial

Importance

Postoperative delirium occurs in 10% to 60% of elderly patients having major surgery and is associated with longer hospital stays, increased hospital costs, and 1-year mortality. Emerging literature suggests that dexmedetomidine sedation in critical care units is associated with reduced incidence of delirium. However, intraoperative use of dexmedetomidine for prevention of delirium has not been well studied.

Objective

To evaluate whether an intraoperative infusion of dexmedetomidine reduces postoperative delirium.

Design, Setting, and Participants

This study was a multicenter, double-blind, randomized, placebo-controlled trial that randomly assigned patients to dexmedetomidine or saline placebo infused during surgery and for 2 hours in the recovery room. Patients were assessed daily for postoperative delirium (primary outcome) and secondarily for postoperative cognitive decline. Participants were elderly (>68 years) patients undergoing major elective noncardiac surgery. The study dates were February 2008 to May 2014.

Interventions

Dexmedetomidine infusion (0.5 µg/kg/h) during surgery and up to 2 hours in the recovery room.

Main Outcomes and Measures

The primary hypothesis tested was that intraoperative dexmedetomidine administration would reduce postoperative delirium. Secondarily, the study examined the correlation between dexmedetomidine use and postoperative cognitive change.

Results

In total, 404 patients were randomized; 390 completed in-hospital delirium assessments (median [interquartile range] age, 74.0 [71.0-78.0] years; 51.3% [200 of 390] female). There was no difference in postoperative delirium between the dexmedetomidine and placebo groups (12.2% [23 of 189] vs 11.4% [23 of 201], P = .94). After adjustment for age and educational level, there was no difference in the postoperative cognitive performance between treatment groups at 3 months and 6 months. Adverse events were comparably distributed in the treatment groups.

Conclusions and Relevance

Intraoperative dexmedetomidine does not prevent postoperative delirium. The reduction in delirium previously demonstrated in numerous surgical intensive care unit studies was not observed, which underscores the importance of timing when administering the drug to prevent delirium.

Trial Registration

clinicaltrials.gov Identifier NCT00561678.

Impact of Delirium After Hip Fracture Surgery on One-Year Mortality in Patients With or Without Dementia: A Case of Effect Modification

OBJECTIVES

We evaluated whether delirium after hip fracture repair modifies the relationship between baseline dementia and one-year mortality after surgery.

METHODS

Patients age 65 years and older undergoing hip fracture repair surgery at John Hopkins Bayview Medical Center between 1999 and 2009 were eligible for this prospective cohort study. Baseline probable dementia was defined as either preoperatively diagnosed dementia per geriatrician or score less than 24 on the Mini-Mental State Examination. Delirium was assessed using the Confusion Assessment Method. Four cognitive groups were defined: 1) neither probable dementia nor delirium (NDD), 2) probable dementia only, 3) delirium only, or 4) delirium superimposed on dementia (DSD). Primary outcome of mortality was obtained through hospital records, obituaries, the National Death Index, and Social Security Death Index.

RESULTS

The current sample comprises 466 subjects (average age: 80.8 ± 7.0 years; 73.6% female). Of these, 77 (17%) were categorized as DSD, 68 (15%) probable dementia only, 73 (16%) delirium only, and 248 (53%) NDD. Cox regression revealed that DSD subjects had a significantly higher hazard of one-year mortality than NDD subjects (hazard ratio [HR]: 1.71, 95% CI: 1.06, 2.77) after adjusting for age, sex, medical comorbidity, and surgery duration. Trends toward greater mortality for probable-dementia and delirium only subjects were not significant (HR: 1.42 [95% CI: 0.80, 2.52] and 1.12 [95% CI: 0.64, 1.95], respectively).

CONCLUSIONS

Delirium after hip fracture repair surgery in patients with preoperative dementia modifies the risk of mortality over the first postoperative year. Patients with DSD have a nearly two-fold greater odds of one-year mortality than those without dementia or delirium.

Design considerations of a randomized controlled trial of sedation level during hip fracture repair surgery: a strategy to reduce the incidence of postoperative delirium in elderly patients

Background Delirium is an acute change in mental status characterized by sudden onset, fluctuating course, inattention, disorganized thinking, and abnormal level of consciousness. The objective of the randomized controlled trial "A STrategy to Reduce the Incidence of Postoperative Delirium in Elderly Patients" (STRIDE) is to assess the effectiveness of light versus heavy sedation on delirium and other outcomes in elderly patients undergoing hip fracture repair surgery. Our goal is to describe the design considerations and lessons learned in planning and implementing the STRIDE trial. Methods Discussed are challenges encountered including (1) how to ensure that we quickly identify, assess the eligibility of, and randomize traumatic hip fracture patients; (2) how to implement interventions that involve continuous monitoring and adjustment during the surgery; and (3) how to measure and ascertain the primary outcome, delirium. Results To address the first challenge, we monitored the operating room schedule more actively than anticipated. We constructed and organized eligibility assessment data collection forms by purpose and by source of information needed to complete them. We decided that randomization needs to take place in the operating room. To address the second challenge, we designed and implemented a treatment protocol and covered the bispectral index monitor to prevent the Anesthesiologist/Anesthetist from being influenced by the bispectral index reading while administering the intervention. Finally, clinical assessment of delirium consisted of standardized interviews of the patient using validated instruments, interviews of those caring for the patient, and review of the medical record. A consensus panel made the final determination of a delirium diagnosis. We note that STRIDE is a single-center trial. The decisions we took may have different implications for multi-center trials. Conclusions Lessons learned are likely to provide useful information to others designing trials in emergency and surgical setting and for those who are interested in unbiased assessment of delirium.

Regional versus General Anesthesia for Promoting Independence after Hip Fracture (REGAIN): protocol for a pragmatic, international multicentre trial

INTRODUCTION

Hip fractures occur 1.6 million times each year worldwide, with substantial associated mortality and losses of independence. At present, anaesthesia care for hip fracture surgery varies widely within and between countries, with general anaesthesia and spinal anaesthesia representing the 2 most common approaches. Limited randomised evidence exists regarding potential short-term or long-term differences in outcomes between patients receiving spinal or general anaesthesia for hip fracture surgery.

METHODS

The REGAIN trial (Regional vs General Anesthesia for Promoting Independence after Hip Fracture) is an international, multicentre, pragmatic randomised controlled trial. 1600 previously ambulatory patients aged 50 and older will be randomly allocated to receive either general or spinal anaesthesia for hip fracture surgery. The primary outcome is a composite of death or new inability to walk 10 feet or across a room at 60 days after randomisation, which will be assessed via telephone interview by staff who are blinded to treatment assignment. Secondary outcomes will be assessed by in-person assessment and medical record review for in-hospital end points (delirium; major inpatient medical complications and mortality; acute postoperative pain; patient satisfaction; length of stay) and by telephone interview for 60-day, 180-day and 365-day end points (mortality; disability-free survival; chronic pain; return to the prefracture residence; need for new assistive devices for ambulation; cognitive impairment).

ETHICS AND DISSEMINATION

The REGAIN trial has been approved by the ethics boards of all participating sites. Recruitment began in February 2016 and will continue until the end of 2019. Dissemination plans include presentations at scientific conferences, scientific publications, stakeholder engagement efforts and presentation to the public via lay media outlets.

TRIAL REGISTRATION NUMBER

NCT02507505, Pre-results.

Sex Differences in Hip Fracture Surgery: Preoperative Risk Factors for Delirium and Postoperative Outcomes

OBJECTIVES

To describe the differences observed in risk factors for delirium and outcomes between men and women undergoing hip fracture repair surgery.

DESIGN

Prospective cohort study.

SETTING

Academic medical center.

PARTICIPANTS

Individuals with acute hip fracture admitted to an academic medical center (N = 431).

MEASUREMENTS

Information on preoperative demographic characteristics, medical history, laboratory results, and postoperative outcomes was obtained according to history and chart review. Delirium was assessed using the Confusion Assessment Method.

RESULTS

The overall incidence of postoperative delirium was 34%, with men more likely to experience postoperative delirium (44.8%) than women (30.2%) (P = .004). Male sex was associated with postoperative delirium in individuals with hip fracture, even after adjusting for other preoperative risk factors. Other significant preoperative risk factors included age, dementia, Parkinson's disease, and American Society of Anesthesiologists classification. Men were also more likely to experience other postoperative complications and have longer hospital length of stay.

CONCLUSION

Men are at higher risk of postoperative delirium after hip fracture repair than women and have more postoperative surgical complications. Their higher risk of postoperative delirium may be due to their underlying preoperative disease severity.

The Impact of Incident Postoperative Delirium on Survival of Elderly Patients After Surgery for Hip Fracture Repair

BACKGROUND

The impact of delirium on survival of elderly patients remains undetermined with conflicting results from clinical studies and meta-analysis. In this study, we assessed the relationship between long-term mortality and incident postoperative delirium in elderly patients undergoing hip fracture repair.

METHODS

Patients ≥65 years old who were not delirious before undergoing hip fracture repair were included in a database maintained prospectively from March 1999 to July 2009. All participating patients underwent delirium assessment on the second postoperative day by using the confusion assessment method. Survival of the participants was determined as of October 2012.

RESULTS

In 459 patients, the mean (SD) period of evaluation from surgery until death or study closure was 4.1 (3.5) years with patients followed for as long as 13.6 years. Preoperative cognitive impairment was present in 120 patients (26.1%), and delirium on the second postoperative day was observed in 151 (32.9%) of these patients. Although univariate analysis demonstrated a strong association between incident postoperative delirium and survival, this relationship did not persist in a multivariate model. Survival was a function of age at the time of surgery (P < 0.001), illness severity as determined by the ASA physical status score (P < 0.001), and duration of admission to the intensive care unit after surgery (P < 0.001). Incorporation of incident postoperative delirium did not meaningfully (P = 0.22) enhance the final survival model. In such a model, the hazard ratio (95% confidence interval) for incident postoperative delirium was 1.25 (0.92-1.48).

CONCLUSIONS

Incident postoperative delirium was not significantly associated with decreased survival in elderly patients undergoing hip fracture repair.

Long-Term Outcomes of Older Adults with and Without Delirium Immediately After Recovery from General Anesthesia for Surgery

OBJECTIVE

Postoperative delirium, occurring days after surgery, is associated with both short- and long-term adverse events. Postanesthesia care unit (PACU) delirium, immediately after recovery from anesthesia, is associated with continued delirium in the succeeding days and adverse cognitive outcomes at discharge. Longer-term consequences are unclear. The objective was to evaluate 18-month outcomes of patients with versus without delirium in the PACU after surgery with general anesthesia.

METHODS

In a prospective, observational, cohort study, 91 consecutive English-speaking patients, aged at least 70 years and capable of independently providing informed consent before surgery, were followed after admission for a surgical procedure in one teaching hospital. Patients completed cognitive testing before surgery. After recovery from general anesthesia, they were evaluated for a DSM-IV diagnosis of delirium. Participants or proxies were evaluated, at a median of 19 months after surgery (interquartile range: 18-20 months), for survival, cognitive and physical functioning, and healthcare utilization outcomes.

RESULTS

All 91 patients or proxies (41 with delirium [45%]) were contacted at follow-up, with 7 deaths (8%) and 3 declining further participation (3%); 81 (96% of survivors) completed follow-up evaluations, demonstrating no significant cognitive or functional decline from baseline, with 75% of the cohort living independently in the community, and no differences in any outcomes between patients with versus without PACU delirium.

CONCLUSION

In a small cohort of older patients evaluated 18 months after surgery, we could not detect an association of delirium diagnosed in the PACU with patient survival, cognitive/physical functioning, and healthcare utilization.

Preoperative risk factors for postoperative delirium following hip fracture repair: a systematic review

OBJECTIVE

Systematically identify preoperative clinical risk factors for incident postoperative delirium in individuals undergoing hip fracture repair in order to guide clinicians in identifying high risk patients at admission.

METHODS

This is a systematic review of prospective observational studies with estimation of association between preoperative risk factors and incident postoperative delirium in multivariate models. Electronic searches were conducted in PubMed, Embase, PsycINFO, CINAHL, Cochrane Library, Proquest Dissertations and Theses, and WorldCatDissertations. Hand searches were conducted in selected journals and their supplements.

RESULTS

Search yielded 6380 titles and abstracts from electronic databases and 72 titles from hand searches, and 10 studies met inclusion criteria. The following risk factors were significant in bivariate models: cognitive impairment, age, gender, institutionalization, functional impairment, body mass index (BMI), albumin, comorbidities, American Society of Anesthesiologist classification, acute medical conditions, polypharmacy, and vision impairment. Among all of these risk factors, cognitive impairment most consistently remained statistically significant after adjusting for other risk factors in multivariate models, followed by BMI/albumin and multiple comorbidities.

CONCLUSION

In our systematic review, cognitive impairment was one of the strongest preoperative risk factors for postoperative delirium after hip fracture surgery. Preoperative cognitive assessment may be one of the most useful methods of identifying those who are at high risk for postoperative delirium and prioritizing delivery of delirium prevention measures.

Sedation depth during spinal anesthesia and survival in elderly patients undergoing hip fracture repair

Low intraoperative Bispectral Index (BIS) values may be associated with increased mortality. In a previously reported trial to prevent delirium, we randomized patients undergoing hip fracture repair under spinal anesthesia to light (BIS >80) or deep (BIS approximately 50) sedation. We analyzed survival of patients in the original trial. Among all patients, mortality was equivalent across sedation groups. However, among patients with serious comorbidities (Charlson score >4), 1-year mortality was reduced in the light (22.2%) vs deep (43.6%) sedation group (hazard ratio [HR], 0.43; 95% confidence interval, 0.19-0.97; P = 0.04) during spinal anesthesia. Similarly, among patients with Charlson score >6, 1-year mortality was reduced in the light (28.6%) vs deep (52.6%) sedation group (HR 0.33; 95% confidence interval, 0.12-0.94; P = 0.04) during spinal anesthesia. Further research on reduced mortality after light sedation during spinal anesthesia is needed.

Role of fracture and repair type on pain and opioid use after hip fracture in the elderly

BACKGROUND AND PURPOSE

Pain after hip fracture repair is related to worse functional outcomes and higher fracture care costs than that for patients with no or less pain. However, to our knowledge, few studies have examined the roles of hip fracture type or surgical procedure as factors influencing postoperative pain or opioid analgesic requirements. Our goal was to determine whether the type of hip fracture or hip fracture repair affects postoperative pain or opioid analgesic requirements in the elderly patient.

METHODS

We conducted a retrospective review of 231 patients ≥65 years old admitted to a hip fracture center for surgical repair. Fracture patterns were classified into femoral neck (FN) versus intertrochanteric (IT), stable versus unstable, and type of surgical repair. Demographic and intraoperative variables, postoperative pain scores, and opioid analgesic use data were collected and analyzed according to the type of hip fracture and type of surgical repair.

RESULTS

There were no differences in postoperative pain when comparing FN versus IT fractures, stable versus unstable fractures, or type of surgical repair. Patients with FN fractures had higher analgesic requirements on postoperative days 1, 2, and 3. There was no difference in postoperative analgesic requirements among patients with stable versus unstable fractures or type of surgical repair. Otherwise, there were no differences in postoperative pain or opioid analgesic use based on the surgical repair or fracture type. Overall, patients with hip fracture experienced low levels of pain.

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.

Evaluation of two delirium screening tools for detecting post-operative delirium in the elderly

BACKGROUND

Postoperative delirium in the elderly is common and associated with poor outcomes, but often goes unrecognized. Delirium screening tools, validated in postoperative settings are lacking. This study compares two screening tools [Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) and Nursing Delirium Symptom Checklist (NuDESC)] with a DSM-IV-based diagnosis of delirium, conducted by neuropsychiatric examination in postoperative settings.

METHODS

Consecutive English-speaking patients, ≥70 yr, undergoing surgery with general anaesthesia and capable of providing informed consent, were recruited. Diagnostic test characteristics were compared for each screening tool vs neuropsychiatric examination, both in the Post-Anaesthesia Care Unit (PACU), and daily during inpatient hospitalization, adjusting for repeated measures.

RESULTS

Neuropsychiatric examination identified delirium in 45% of 91 patients evaluated in the PACU and in 32% of 166 subsequent delirium assessments on the ward in the 58 admitted patients. The sensitivity [95% confidence interval (CI)] of delirium detection of the CAM-ICU in the PACU, and in all repeated assessments was 28% (16-45%) and 28% (17-42%), respectively; for the NuDESC (scoring threshold ≥2), 32% (19-48%) and 29% (19-42%), respectively, and the NuDESC (threshold ≥1), 80% (65-91%) and 72% (60-82%), respectively. Specificity was >90% for both the CAM-ICU and the NuDESC (threshold ≥2); specificity for the NuDESC (threshold ≥1), in the PACU was 69% (54-80%) and 80% (73-85%) for all assessments.

CONCLUSIONS

While highly specific, neither CAM-ICU nor NuDESC (threshold ≥2) are adequately sensitive to identify delirium post-operatively; NuDESC (threshold ≥1) increases sensitivity, but reduces specificity.

Case discussion: large volume blood loss and delirium in a patient with subtrochanteric fracture, dementia, and multiple comorbidities

This case presents a discussion of a 92-year-old man with multiple comorbidities, who presents with a subtrochanteric fracture. His course is complicated by large volume blood loss intraoperatively, requiring intensive care unit (ICU) monitoring postoperatively. His course is also complicated by delirium.

Predisposing factors for postoperative delirium after hip fracture repair in individuals with and without dementia

OBJECTIVES

Based on a multifactorial model of delirium, to compare the types and magnitude of pre- and intraoperative predisposing factors for incident delirium in a stratified sample of individuals with and without preoperative dementia undergoing acute hip fracture repair.

DESIGN

Prospective cohort study.

SETTING

Academic medical center.

PARTICIPANTS

Four hundred twenty-five individuals with acute hip fracture and without delirium (mean age 80.2 ± 6.8, 73.2% female, 33.1% with probable dementia) admitted to a multidisciplinary hip fracture repair service.

MEASUREMENTS

A research nurse assessed each participant for delirium based on the Confusion Assessment Method (CAM) before study enrollment and from the second postoperative day until hospital discharge.

RESULTS

The incidence of delirium was higher in the group with probable dementia (56%) than in the group without dementia (26%) (P < .001). In the group without dementia (n = 284), age (odds ratio (OR) = 1.07, 95% CI = 1.02-1.13), male sex (OR = 2.81, 95% CI = 1.40-5.64), body mass index (OR = 0.92, 95% CI = 0.86-0.99), number of medical comorbidities (OR = 1.15, 95% CI = 1.01-1.32), and duration of surgery longer than 2 hours (OR = 2.53, 95% CI = 1.20-4.88) were independently associated with postoperative delirium. In the group with probable dementia, only the lag time from the emergency department to operating room was significantly associated (OR = 2.83, 95% CI = 1.24-2.25) with delirium.

CONCLUSION

Preoperative determination of dementia status is important for risk stratification for incident delirium after acute hip fracture repair surgery because types and magnitude of predisposing risk factors for postoperative delirium substantially differ based on preoperative dementia status.

The Johns Hopkins Delirium Consortium: a model for collaborating across disciplines and departments for delirium prevention and treatment

Delirium is an important syndrome affecting inpatients in various hospital settings. This article focuses on multidisciplinary and interdepartmental collaboration to advance efforts in delirium clinical care and research. The Johns Hopkins Delirium Consortium, which includes members from the disciplines of nursing, medicine, rehabilitation therapy, psychology, and pharmacy within the departments and divisions of anesthesiology, geriatrics, oncology, orthopedic surgery, psychiatry, critical care medicine, and physical medicine and rehabilitation at the Johns Hopkins Hospital and Johns Hopkins Bayview Medical Center, is one model of such collaboration. This article describes the process involved in developing functional collaboration around delirium and highlights projects, opportunities, and challenges resulting from them.

Postoperative opioid consumption and its relationship to cognitive function in older adults with hip fracture

OBJECTIVES

To determine the relationship between opioid consumption and cognitive impairment after hip fracture repair.

DESIGN

Prospective study of consecutive patients.

SETTING

Johns Hopkins Bayview Medical Center, Baltimore, Maryland.

PARTICIPANTS

Two hundred thirty-six participants aged 65 and older undergoing hip fracture repair.

MEASUREMENTS

Older adults without preoperative delirium who underwent hip fracture repair between April 2005 and July 2009 were followed for pain, opioid consumption, and postoperative delirium. Participants were tested for delirium using the Confusion Assessment Method preoperatively and midmorning on Postoperative Day 2. The nursing staff assessed pain on a numeric oral scale (range 0-10). Opioid analgesia was provided in response to pain at rest to achieve scores of 3 or less. Opioid consumption was analyzed with respect to the occurrence of incident postoperative delirium, presence of dementia, and other demographic variables.

RESULTS

Of the 236 participants, 66 (28%) had dementia, and 213 (90%) received opioids postoperatively, including 55 (83%) with dementia and 158 (93%) without. There was no association between the use of any postoperative opioid and incident delirium (P = .61) in participants with (P = .33) and without (P = .40) dementia. Dementia, but not postoperative delirium, was associated with less opioid use (P < .001 for dementia; P = .12 for delirium; P = .04, for their interaction; Wald chi-square = 142.8, df = 7). Opioid dose (P ≥ .59) on Postoperative Days 1 and 2 was not predictive of incident delirium. Dementia (P < .001) and intensive care unit admission (P = .006), not opioid consumption, were the most important predictors of incident postoperative delirium.

CONCLUSION

Concern for postoperative delirium should not prevent the use of opioid analgesic therapy sufficient to achieve a generally accepted level of comfort in individuals with or without preexisting cognitive impairment.

General anesthesia occurs frequently in elderly patients during propofol-based sedation and spinal anesthesia

STUDY OBJECTIVE

To test the hypothesis that sedation in elderly patients is often electrophysiologically equivalent to general anesthesia (GA).

DESIGN

Prospective, observational study.

SETTING

Operating room of a university medical center.

PATIENTS

40 elderly patients (>or=65 yrs of age) undergoing hip fracture repair with spinal anesthesia and propofol-based sedation.

INTERVENTIONS

In the routine practice group (RP; n = 15), propofol sedation was administered per the usual routine of the anesthesiologist. In the targeted sedation group (TS; n = 25), sedation was titrated to an observer's assessment of alertness/sedation (OAA/S) score of 4 (ie, lethargic in response to name called) to 5 (ie, awake and alert).

MEASUREMENTS

Both patient groups underwent processed electroencephalographic monitoring using bispectral index (BIS) intraoperatively. BIS levels were compared between groups to determine amount of surgical time spent in GA (BIS <or= 60).

MAIN RESULTS

In the RP group, subjects spent 32.2% of surgical time at BIS levels consistent with GA. Although averaged BIS values during surgery increased from (mean +/- SD) 71 +/- 16 to 88 +/- 9 (P < 0.001), GA was still observed during 5% of surgical time in the TS group. Overall, 13 of 15 (87%) RP group patients and 11 of 25 (44%) TS group patients (P < 0.010) experienced some period of GA.

CONCLUSIONS

BIS levels consistent with GA occur frequently in elderly patients during propofol-based sedation for spinal anesthesia. Altering routine practice such that sedation is titrated to a targeted clinically-determined sedation level reduces - but does not eliminate - this incidence.

Preventing postoperative complications in the elderly

Postoperative complications are directly related to poor surgical outcomes in the elderly. This review outlines evidence based quality initiatives focused on decreasing neurologic, cardiac, and pulmonary complications in the elderly surgical patient. Important anesthesia quality initiatives for prevention of delirium, the most common neurologic complication in elderly surgical patients, are outlined. There are few age-specific quality measures aimed at prevention of cardiac and pulmonary complications. However, some recommendations for adults can be applied to the geriatric surgical population. In the future, process measures may provide a more global assessment of quality in the elderly surgical population.

Eight-year follow-up on the effect of a hip fracture service on patient care and outcome

The purpose of this study was to evaluate the 8-year effect of a hip fracture service on time to surgery; duration of surgery; length of stay in acute care, intensive care, and rehabilitation unit; and incidence of postoperative complications and in-hospital mortality. The study group consisted of 50 female patients 65 years of age or older who were treated for hip fractures in 1999 and 50 case-, age-, and American Society of Anesthesiologists score-matched female patients treated in 2006. Group differences were compared via the Student paired t test and χ² analysis (statistical significance, p ≤ .05). The 2006 group had a significantly shorter mean surgical time than did the 1999 group, but time to surgery did not change. The 2006 group showed improvements (but not statistically significant ones) in length of stay in acute care, intensive care, and rehabilitation unit, and in the incidence of complications and in-hospital mortality.

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

OBJECTIVE

To determine whether limiting intraoperative sedation depth during spinal anesthesia for hip fracture repair in elderly patients can decrease the prevalence of postoperative delirium.

PATIENTS AND METHODS

We performed a double-blind, randomized controlled trial at an academic medical center of elderly patients (>or=65 years) without preoperative delirium or severe dementia who underwent hip fracture repair under spinal anesthesia with propofol sedation. Sedation depth was titrated using processed electroencephalography with the bispectral index (BIS), and patients were randomized to receive either deep (BIS, approximately 50) or light (BIS, >or=80) sedation. Postoperative delirium was assessed as defined by Diagnostic and Statistical Manual of Mental Disorders (Third Edition Revised) criteria using the Confusion Assessment Method beginning at any time from the second day after surgery.

RESULTS

From April 2, 2005, through October 30, 2008, a total of 114 patients were randomized. The prevalence of postoperative delirium was significantly lower in the light sedation group (11/57 [19%] vs 23/57 [40%] in the deep sedation group; P=.02), indicating that 1 incident of delirium will be prevented for every 4.7 patients treated with light sedation. The mean +/- SD number of days of delirium during hospitalization was lower in the light sedation group than in the deep sedation group (0.5+/-1.5 days vs 1.4+/-4.0 days; P=.01).

CONCLUSION

The use of light propofol sedation decreased the prevalence of postoperative delirium by 50% compared with deep sedation. Limiting depth of sedation during spinal anesthesia is a simple, safe, and cost-effective intervention for preventing postoperative delirium in elderly patients that could be widely and readily adopted.

Postoperative delirium in the elderly surgical patient

Delirium is a common complication in the geriatric population following cardiac and noncardiac procedures. Postoperative delirium is a significant financial burden on the United States health care system and is independently associated with prolonged hospital stay, increased risk of early and long term mortality, increased physical dependence, and an increased rate of nursing home placement. The Confusion Assessment Method (CAM) is a bedside rating scale developed to assist nonpsychiatrically trained clinicians in the rapid and accurate diagnosis of delirium. The CAM has been adapted for use in ventilated intensive care unit (ICU) patients in the form of the CAM-ICU. The onset of delirium involves an interaction between predisposing and precipitating risk factors for delirium. The mainstay of delirium management is prevention. The approach involves control or elimination of modifiable risk factors. It is controversial whether anesthetic technique determines delirium. However, important modifiable risk factors under the anesthesiologist's control include adequate postoperative pain management, careful drug selection, and embracing and participating in a multidisciplinary care model for these complicated patients.

Detection and management of pre-existing cognitive impairment and associated behavioral symptoms in the Intensive Care Unit

Recent increase in both the elderly population and associated incidence of dementia are of critical importance to patient care in ICUs in the United States. Identification of pre-existing cognitive impairment, such as mild cognitive impairment and dementia, could prevent delirium and associated morbidity and mortality in the ICU. Additionally, noncognitive behavioral symptoms, such as depression, psychosis, agitation, and catastrophic reactions, are common in patients with pre-existing cognitive impairment. Detection and management of noncognitive behavioral symptoms associated with MRI and dementia in ICU leads to improved delivery of life-saving critical care.

Hippocampus bcl-2 and bax expression and neuronal apoptosis after moderate hypothermic cardiopulmonary bypass in rats

Using a rat model of moderate hypothermic (26 degrees C-28 degrees C) cardiopulmonary bypass (CPB) with hemodilution, we investigated hippocampal apoptotic gene expression and neuronal apoptosis up to 6 h after CPB. The CPB was performed on male rats (380-400 g) under general anesthesia with isoflurane and fentanyl. The right atrium and tail artery were cannulated, and a peristaltic pump and membrane oxygenator were used for CPB. Two groups were studied: Group 1 consisted of fasted rats (n = 15) subjected to 60 min of moderate hypothermic nonpulsatile CPB; Group 2 consisted of sham-operated rats (n = 15). At 1 h after CPB, in 6 rats per group, hippocampus was processed for the apoptotic gene (bcl-2 and bax) messenger RNAs detection by reverse transcriptase polymerase chain reaction, and messenger RNA expression was determined by the ratio of the polymerase chain reaction product of bcl-2 or bax to the beta-actin gene. At 6 h after CPB, in 6 rats per group, hippocampus expression of Bcl-2 and bax protein was determined by immunohistochemistry, and neuronal apoptosis was detected by TUNEL. At 6 h after CPB, in three rats per group, changes in hippocampal CA1 neuronal ultra structure were determined with electron microscopy. Group 1 had increased ratios of bcl-2/beta-actin, bax/beta-actin, and bax/bcl-2 mRNA at 1 h after CPB (bcl-2/beta-actin, 0.82 +/- 0.14 versus 0.63 +/- 0.07; P = 0.03; bax/beta-actin, 1.04 +/- 0.14 versus 0.56 +/- 0.03; P = 0.00; bax/bcl-2, 1.31 +/- 0.12 versus 0.84 +/- 0.09; P = 0.02; Group 1 versus Group 2, respectively). Group 1 had increased bcl-2 and bax protein expression in hippocampal CA1 region at 6 h after CPB (bcl-2, 0.18 +/- 0.05 versus 0.09 +/- 0.01; P = 0.02; bax, 0.20 +/- 0.06 versus 0.04 +/- 0.02; P = 0.01; Group 1 versus Group 2, respectively). Group 1 had increased TUNEL staining in hippocampus CA1 at 6 h after CPB (0.14 +/- 0.02 versus 0.03 +/- 0.01; P = 0.00; Group 1 versus Group 2, respectively). In Group 1 CA1 hippocampus neurons, ultra-structural changes consistent with apoptosis occurred. In rats, moderate hypothermic CPB with hemodilution is associated with CA1 hippocampus bax and bcl-2 gene expression and neuronal apoptosis during the early post-CPB recovery period.

Recovery Room Delirium Predicts Postoperative Delirium After Hip-Fracture Repair

In this study, we sought to determine the incidence of recovery room delirium in elderly patients having hip-fracture repair under general anesthesia and to discover whether recovery room delirium is associated with continuing postoperative delirium. In this prospective study, patients undergoing hip-fracture repair were anesthetized using a standardized protocol. In addition, postoperative pain management was standardized in both the postoperative anesthesia care unit and in the hospital ward. The presence of delirium was determined using the confusion assessment method (CAM) score. Recovery room delirium was assessed by obtaining a CAM score at 60 min after discontinuation of isoflurane. Postoperative delirium was assessed by obtaining a daily CAM score during the postoperative in-hospital recovery period. Fifty patients consented to the study and 47 patients were included in the analysis (surgery cancelled postinduction n = 1; nonadherence to protocol n = 2). Average patient age was 77 +/- 1 (mean +/- SE) yr (range, 56-98 yr). Seventy-seven percent of the study patients were ASA class III or more. The prevalence of recovery room delirium was 45%. The prevalence of postoperative delirium was 36%. Recovery room delirium predicted postoperative delirium (P < 0.001, Fisher's exact test) with a sensitivity of 100% and a specificity of 85%. Analgesic doses administered in the postoperative anesthesia care unit and ward were similar in patients with or without postoperative delirium. Results of this study show that recovery room delirium is a strong predictor of postoperative delirium.

IMPLICATIONS

In patients undergoing hip-fracture repair, recovery room delirium is a strong predictor of postoperative delirium when using a standardized protocol for general anesthesia and postoperative pain management.

Brief postoperative delirium in hip fracture patients affects functional outcome at three months

It is unclear how brief postoperative delirium (DEL) affects functional outcomes. In this study, we sought to determine if patients with brief postoperative DEL (<6-wk duration) have different living situations when compared with non-DEL patients after hip fracture repair. In a prospective study, patients admitted to the geriatric hip fracture service were assessed every postoperative day for the presence of DEL using the confusion assessment method (CAM) score. Patients were reassessed at 6 wk and 3 mo postoperatively for CAM score, current living situation, and activities of daily living. Group comparisons were tested after dividing patients into two groups: DEL (DEL; [+] CAM at any time during the postoperative period while in the hospital); no-DEL (no DEL; [-] CAM throughout the postoperative period while in the hospital). The study included 92 patients of whom 26 (28%) were CAM (+) after surgery. At 6 wk follow-up, n = 81; at 3 mo follow-up, n = 76. Eight patients died during the study. At 6 wk and 3 mo, a larger percentage of DEL patients were not living with a family member (27% versus 8% patients not living with a family member at 3 mo follow-up in DEL and no-DEL, respectively). There was no difference in activities of daily living by 3 mo. We conclude that brief postoperative DEL lasting <6 wk is a determining factor for poor long-term functional outcome after hip fracture repair, because it significantly impacts the ability to live independently.

IMPLICATIONS

Brief postoperative delirium lasting <6 wk is a determining factor for poor long-term functional outcome after hip fracture repair, because it significantly impacts the ability to live independently.

Age associated issues: geriatrics

The effects of aging on the body are numerous, but the most important point with regard to surgery is to differentiate the effects of aging from those of the pathology associated with a disease process that may also be present in the elderly patient. Studies tend to validate the premise that there are no labs mandated solely because of a patient's age. Rather, the physician should analyze the geriatric patient with reference to the nature of the surgery emergent versus elective; the degree of risk for the surgical procedure itself-that is high-risk, intermediate--risk, or low-risk surgery; while bearing in mind the patient's overall physiologic state. In assessing a patient's overall physiologic state an organ systems based approach focusing on the cardiac, respiratory, renal, hepatic, endocrine, nutritional, and neurologic systems may be warranted and beneficial. In the elderly population one of the key predictors of perioperative complications seems to be the geriatric patient's preoperative condition and preoperative level of functioning.

Preoperative factors associated with postoperative change in confusion assessment method score in hip fracture patients

Postoperative delirium is a major problem in elderly patients undergoing surgical repair of hip fracture. It is imperative to identify potentially treatable preoperative factors associated with the onset of postoperative delirium to optimize outcome. We sought to determine what preoperative variables are associated with postoperative delirium in geriatric patients undergoing surgical repair of hip fracture. In a prospective, IRB-approved study, patients admitted to the geriatric hip fracture service were examined daily in the hospital for the occurrence of postoperative delirium. All patients with a preoperative diagnosis of dementia or delirium were eliminated. A positive confusion assessment method score ([+]CAM) was used to determine the presence of postoperative delirium during the acute hospital stay. To determine the association between preoperative variables (demographics, laboratory values, and comorbidities) and postoperative (+)CAM scores, chi(2) and logistic regression analysis were performed with calculation for the odds ratios (OR). One-hundred-sixty-eight patients (72% women) were included in the analysis. Twenty-eight percent (n = 47) of patients had a (+)CAM score. Three variables were significant predictors of a (+)CAM score: (a) normal white blood cell count (OR, 2.2), (b) abnormal serum sodium (OR, 2.4); and (c) ASA physical status >II (OR, 11.3). The results suggest that preoperative medical conditions (abnormal serum sodium and ASA physical status >II) and an inability to mount a stress response (normal white blood cell count) may influence the patient's postoperative mental status. In particular, two of the risk factors we identified may be amenable to therapy and are abnormal serum sodium and lack of an increase in white blood cell count during the stress of trauma and surgery.

IMPLICATIONS

This prospective study investigated preoperative variables that are predictive of postoperative delirium in geriatric patients undergoing surgical repair of hip fracture. The results suggest that the patient's preoperative medical condition and inability to mount a stress response influence postoperative delirium.

Does intraoperative fluid management in spine surgery predict intensive care unit length of stay?

STUDY OBJECTIVE

To determine whether intraoperative fluid management in spine surgery predicts postoperative intensive care unit length of stay (ICU LOS).

DESIGN

Retrospective case series.

SETTING

University-affiliated medical center.

PATIENTS

103 adult ASA physical status I, II, and III patients undergoing spine surgery.

INTERVENTIONS

Patients were divided into three LOS groups: no ICU stay (LOS0) (n = 26), 1 day ICU stay (LOS1) (n = 48), and ICU stay > 1 day (LOS2) (n = 29). Measurements were analyzed by groups using the Kruskal-Wallis and Mann-Whitney tests, and linear regression.

MEASUREMENTS

Demographics, comorbidity, length of surgery, surgical procedure, and intraoperative fluids were recorded.

MAIN RESULTS

The important differences in perioperative fluid management among the three groups included estimated blood loss (612 +/- 480 mL, 1853 +/- 1175 mL, 2702 +/- 1771 mL, means +/- SD); total crystalloid administration (2715 +/- 1396 mL, 5717 +/- 2574 mL, 7281 +/- 3417 mL); and total blood administration (92 +/- 279 mL, 935 +/- 757 mL, 1542 +/- 1230 mL) in LOS0, LOS1, and LOS2, respectively. The mixture of surgical procedures was similar in LOS1 and LOS2; and differed from LOS0. Predictors of ICU LOS included age, ASA physical status, surgical procedure, total crystalloid administration, and platelet administration. Surgical procedure and total crystalloid administration correlated (Pearson correlation coefficient = 0.441; p = 0.000) and were not related to age or ASA physical status.

CONCLUSIONS

Total crystalloid administration during spine surgery does predict ICU LOS. In addition, total crystalloid administration is closely related to the surgical procedure. Given that the mixture of surgical procedures was similar in LOS1 and LOS2, but differed in estimated blood loss, total crystalloid administration, and total blood administration; intraoperative fluid management during spine surgery only predicts ICU LOS insofar as total crystalloid administration is related to the surgical procedure.

Estrogen decreases infarct size after temporary focal ischemia in a genetic model of type 1 diabetes mellitus

BACKGROUND AND PURPOSE

It is unclear how genetic type 1 diabetes mellitus (DM) influences infarct size when blood glucose is tightly controlled. The aim of this study was to determine the effect of genetic type 1 DM, as occurs in BB rats, on infarct size after transient unilateral middle cerebral artery occlusion (MCAO) in male and female rats. In addition, studies suggest that male type 1 DM rats have a higher incidence of end-organ complications than do females. A second aim of this study was to determine the effect of chronic 17beta-estradiol (E(2)) administration on infarct size in male BB rats.

METHODS

Diabetic male (MDiab, n=14) and female (FDiab, n=8) BB rats were studied and compared with background strain Wistar rats (MWist, n=16; FWist, n=14). Two additional male cohorts (MWist+E(2), n=15; MDiab+E(2), n=14) received subcutaneous 25 microg E(2) implants 7 to 10 days before MCAO. Rats underwent 1 hour of MCAO followed by 22 hours of reperfusion. Physiological variables were controlled among groups, and the intraischemic laser Doppler flow signal was reduced similarly in all animals. Infarction volume was evaluated by 2,3,5-triphenyltetrazolium chloride staining and image analysis.

RESULTS

Preischemic blood glucose was 94+/-5, 127+/-13, 90+/-15, 63+/-18, 122+/-8, and 81+/-14 mg/dL in MWist, FWist, MDiab, FDiab, MWist+E(2), and MDiab+E(2) rats, respectively (mean+/-SE). Intraischemic laser Doppler flow was reduced to 20% to 25% of baseline in all groups. Striatal infarct size (percentage of ipsilateral caudate putamen) was increased in male diabetic rats relative to nondiabetic MWist rats (41+/-3% versus 28+/-3%). Striatal injury was not increased in FDiab rats, and infarction volume was smaller than that in FWist rats (23+/-4% in FWist versus 13+/-3% in FDiab). Chronic estrogen treatment reduced cortical and striatal infarction in MDiab+E(2) rats compared with untreated MDiab rats.

CONCLUSIONS

Type 1 DM is associated with increased infarct size after temporary MCAO, despite tight control of blood glucose. The deleterious effect of DM is evident only in males rats; female diabetic BB rats sustain small infarcts. Chronic E(2) treatment reduced injury in the male BB rat, providing neuroprotection even in the presence of DM. These data suggest that genetic diabetes even with mild glucose elevation plays a role in determining neuropathology in experimental stroke. However, factors such as reproductive steroids also determine outcome in DM stroke.

Apoptosis and necrosis occur in separate neuronal populations in hippocampus and cerebellum after ischemia and are associated with differential alterations in metabotropic glutamate receptor signaling pathways

It was evaluated whether postischemic neurodegeneration is apoptosis and occurs with alterations in phosphoinositide-linked metabotropic glutamate receptors (mGluRs) and their associated signaling pathways. A dog model of transient global incomplete cerebral ischemia was used. The CA1 pyramidal cells and cerebellar Purkinje cells underwent progressive delayed degeneration. By in situ end-labeling of DNA, death of CA1 and Purkinje cells was greater at 7 days than 1 day after ischemia, whereas death of granule neurons in dentate gyrus and cerebellar cortex was greater at 1 than at 7 days. Ultrastructurally, degenerating CA1 pyramidal neurons and cerebellar Purkinje cells were necrotic; in contrast, degenerating granule neurons were apoptotic. In agarose gels of regional DNA extracts, random DNA fragmentation coexisted with internucleosomal fragmentation. By immunoblotting of regional homogenates, mGluR1alpha, mGluR5, phospholipase Cbeta (PLCbeta), and Galphaq/11 protein levels in hippocampus at 1 and 7 days after ischemia were similar to control levels, but in cerebellar cortex, mGluR1alpha and mGluR5 were decreased but PLCbeta was increased. By immunocytochemistry, mGluR and PLCbeta immunoreactivity dissipated in CA1 and cerebellar Purkinje cell/ molecular layers, whereas immunoreactivities for these proteins were enhanced in granule neurons. It was concluded that neuronal death after global ischemia exists as two distinct, temporally overlapping forms in hippocampus and cerebellum: necrosis of pyramidal neurons and Purkinje cells and apoptosis of granule neurons. Neuronal necrosis is associated with a loss of phosphoinositide-linked mGluR transduction proteins, whereas neuronal apoptosis occurs with increased mGluR signaling.

Protein kinase C expression and activity after global incomplete cerebral ischemia in dogs

BACKGROUND AND PURPOSE

Studies suggest that protein kinase C (PKC) activation during ischemia plays an important role in glutamate neurotoxicity and that PKC inhibition may be neuroprotective. We tested the hypothesis that elevations in the biochemical activity and protein expression of Ca2+-dependent PKC isoforms occur in hippocampus and cerebellum during the period of delayed neurodegeneration after mild brain ischemia.

METHODS

We used a dog model of 20 minutes of global incomplete ischemia followed by either 6 hours, 1 day, or 7 days of recovery. Changes in PKC expression (Western blotting and immunocytochemistry) and biochemical activity were compared with neuropathology (percent ischemically damaged neurons) by means of hematoxylin and eosin staining.

RESULTS

The percentage of ischemically damaged neurons increased from 13+/-4% to 52+/-10% in CA1 and 24+/-11% to 69+/-6% in cerebellar Purkinje cells from 1 to 7 days, respectively. The occurrence of neuronal injury was accompanied by sustained increases in PKC activity (240% and 211% of control in hippocampus and cerebellum, respectively) and increased protein phosphorylation as detected by proteins containing phosphoserine residues. By Western blotting, the membrane-enriched fraction showed postischemic changes in protein expression with increases of 146+/-64% of control in hippocampal PKCalpha and increases of 138+/-38% of control in cerebellar PKCalpha, but no changes in PKCbeta and PKCgamma were observed. By immunocytochemistry, the neuropil of CA1 and CA4 in hippocampus and the radial glia in the molecular layer of cerebellum showed increased PKCalpha expression after ischemia.

CONCLUSIONS

This study shows that during the period of progressive ischemic neurodegeneration there are regionally specific increases in PKC activity, isoform-specific increases in membrane-associated PKC, and elevated protein phosphorylation at serine sites.

Neurodegeneration in excitotoxicity, global cerebral ischemia, and target deprivation: A perspective on the contributions of apoptosis and necrosis

In the human brain and spinal cord, neurons degenerate after acute insults (e.g., stroke, cardiac arrest, trauma) and during progressive, adult-onset diseases [e.g., amyotrophic lateral sclerosis, Alzheimer's disease]. Glutamate receptor-mediated excitotoxicity has been implicated in all of these neurological conditions. Nevertheless, effective approaches to prevent or limit neuronal damage in these disorders remain elusive, primarily because of an incomplete understanding of the mechanisms of neuronal death in in vivo settings. Therefore, animal models of neurodegeneration are crucial for improving our understanding of the mechanisms of neuronal death. In this review, we evaluate experimental data on the general characteristics of cell death and, in particular, neuronal death in the central nervous system (CNS) following injury. We focus on the ongoing controversy of the contributions of apoptosis and necrosis in neurodegeneration and summarize new data from this laboratory on the classification of neuronal death using a variety of animal models of neurodegeneration in the immature or adult brain following excitotoxic injury, global cerebral ischemia, and axotomy/target deprivation. In these different models of brain injury, we determined whether the process of neuronal death has uniformly similar morphological characteristics or whether the features of neurodegeneration induced by different insults are distinct. We classified neurodegeneration in each of these models with respect to whether it resembles apoptosis, necrosis, or an intermediate form of cell death falling along an apoptosis-necrosis continuum. We found that N-methyl-D-aspartate (NMDA) receptor- and non-NMDA receptor-mediated excitotoxic injury results in neurodegeneration along an apoptosis-necrosis continuum, in which neuronal death (appearing as apoptotic, necrotic, or intermediate between the two extremes) is influenced by the degree of brain maturity and the subtype of glutamate receptor that is stimulated. Global cerebral ischemia produces neuronal death that has commonalities with excitotoxicity and target deprivation. Degeneration of selectively vulnerable populations of neurons after ischemia is morphologically nonapoptotic and is indistinguishable from NMDA receptor-mediated excitotoxic death of mature neurons. However, prominent apoptotic cell death occurs following global ischemia in neuronal groups that are interconnected with selectively vulnerable populations of neurons and also in nonneuronal cells. This apoptotic neuronal death is similar to some forms of retrograde neuronal apoptosis that occur following target deprivation. We conclude that cell death in the CNS following injury can coexist as apoptosis, necrosis, and hybrid forms along an apoptosis-necrosis continuum. These different forms of cell death have varying contributions to the neuropathology resulting from excitotoxicity, cerebral ischemia, and target deprivation/axotomy. Degeneration of different populations of cells (neurons and nonneuronal cells) may be mediated by distinct or common causal mechanisms that can temporally overlap and perhaps differ mechanistically in the rate of progression of cell death.

The neurologic implications of diabetic hyperglycemia during surgical procedures at increased risk for brain ischemia

The neurologic implications of diabetic hyperglycemia depend on whether the ischemic insult is permanent or temporary. Laboratory studies show that following permanent focal ischemia, a situation analogous to stroke, diabetic hyperglycemia is protective in the penumbral region, whereas it may slightly increase infarct size. In addition, clinical studies cannot unequivocally attribute poor outcome in diabetic stroke patients to hyperglycemia. Thus, both laboratory and clinical studies have been unable to define a cause and effect relationship between diabetic hyperglycemia and neurologic outcome following stroke. On the other hand, diabetic hyperglycemia is an important determinant of neurologic outcome following temporary focal ischemia (analogous to temporary occlusion of a cerebral vessel) and global ischemia (analogous to circulatory arrest). Based on laboratory studies, aggressive insulin-based blood glucose management with the goal of euglycemia is imperative prior to temporary ischemia. However, intraoperative ischemic events are overwhelmingly of a permanent focal nature, and the neurologic implications of diabetic hyperglycemia for the vast majority of surgical procedures at increased risk for brain ischemia are minimal. It is only in circumstances where temporary focal or global ischemia are used as part of the surgical procedure that aggressive insulin-based blood glucose management is warranted.