Delirium after spinal surgery in Korean population

The interrelationship between multiple long-term conditions (MLTC) and delirium: a scoping review

INTRODUCTION

Delirium and multiple long-term conditions (MLTC) share numerous risk factors and have been shown individually to be associated with adverse outcomes following hospitalisation. However, the extent to which these common ageing syndromes have been studied together is unknown. This scoping review aims to summarise our knowledge to date on the interrelationship between MLTC and delirium.

METHODS

Searches including terms for delirium and MLTC in adult human participants were performed in PubMed, EMBASE, Medline, Psycinfo and CINAHL. Descriptive analysis was used to summarise findings, structured according to Synthesis Without Meta-analysis reporting guidelines.

RESULTS

After removing duplicates, 5256 abstracts were screened for eligibility, with 313 full-texts sought along with 17 additional full-texts from references in review articles. In total, 140 met inclusion criteria and were included in the final review. Much of the literature explored MLTC as a risk factor for delirium (n = 125). Fewer studies explored the impact of MLTC on delirium presentation (n = 5), duration (n = 3) or outcomes (n = 6) and no studies explored how MLTC impacts the treatment of delirium or whether having delirium increases risk of developing MLTC. The most frequently used measures of MLTC and delirium were the Charlson Comorbidity Index (n = 98/140) and Confusion Assessment Method (n = 81/140), respectively.

CONCLUSION

Existing literature largely evaluates MLTC as a risk factor for delirium. Major knowledge gaps identified include the impact of MLTC on delirium treatment and the effect of delirium on MLTC trajectories. Current research in this field is limited by significant heterogeneity in defining both MLTC and delirium.

Risk factors of postoperative delirium following spine surgery: A meta-analysis of 50 cohort studies with 1.1 million participants

Objectives

Postoperative delirium (POD) is considered to be a common complication of spine surgery. Although many studies have reported the risk factors associated with POD, the results remain unclear. Therefore, we performed a meta-analysis to identify risk factors for POD among patients following spinal surgery.

Methods

We systematically searched the PubMed, Embase and the Cochrane Library for relevant articles published from 2006 to February 1, 2023 that reported risk factors associated with the incidence of POD among patients undergoing spinal surgery. The Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed, and random effects models were used to estimate pooled odds ratio (OR) estimates with 95 % confidence intervals (CIs) for each factor. The evidence from observational studies was classified according to Egger's P value, total sample size, and heterogeneity between studies.

Results

Of 11,329 citations screened, 50 cohort studies involving 1,182,719 participants met the inclusion criteria. High-quality evidence indicated that POD was associated with hypertension, diabetes mellitus, cardiovascular disease, pulmonary disease, older age (>65 years), patients experiencing substance use disorder (take drug ≥1 month), cerebrovascular disease, kidney disease, neurological disorder, parkinsonism, cervical surgery, surgical site infection, postoperative fever, postoperative urinary tract infection, and admission to the intensive care unit (ICU). Moderate-quality evidence indicated that POD was associated with depression, American Society of Anesthesiologists (ASA) fitness grade (>II), blood transfusion, abnormal potassium, electrolyte disorder, length of stay, inability to ambulate and intravenous fluid volume.

Conclusions

Conspicuous risk factors for POD were mainly patient- and surgery-related. These findings help clinicians identify high-risk patients with POD following spinal surgery and recognize the importance of early intervention.

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.

Preoperative Risk Factors Associated with Increased Incidence of Postoperative Delirium: Systematic Review of Qualified Clinical Studies

Postoperative delirium (POD) is an acute alteration of mental state, characterized by reduced awareness and attention, occurring up to five postoperative days after recovery from anesthesia. Several original studies and reviews have identified possible perioperative POD risk factors; however, there is no comprehensive review of the preoperative risk factors in patients diagnosed with POD using only validated diagnostic scales. The aim of this systematic review was to report the preoperative risk factors associated with an increased incidence of POD in patients undergoing non-cardiac and non-brain surgery. The reviewed studies included original research papers that used at least one validated diagnostic scale to identify POD occurrence for more than 24 h. A total of 6475 references were retrieved from the database search, with only 260 of them being suitable for further review. Out of the 260 reviewed studies, only 165 that used a validated POD scale reported one or more preoperative risk factors. Forty-one risk factors were identified, with various levels of statistical significance. The extracted risk factors could serve as a preoperative POD risk assessment workup. Future studies dedicated to the further evaluation of the specific preoperative risk factors' contributions to POD could help with the development of a weighted screening tool.

Effect of Preoperative Oral Saline Administration on Postoperative Delirium in Older Persons: A Randomized Controlled Trial

Objective

Postoperative delirium (POD) seriously affects recovery of older persons, increasing their mortality rate after surgery. We aimed to evaluate preoperative oral saline administration on postoperative delirium in older persons undergoing spinal decompression.

Design

A randomised controlled trial in a large tertiary hospital.

Setting and Participants

A total of 76 older persons (≧65 years old) undergoing spinal surgery from May 2020 to January 2021.

Methods

Older persons (65–83 years old) who underwent elective spinal canal decompression were randomly grouped into either the control group (n = 38) or the intervention group (n = 38). The control group was forbidden from drinking 8 hours prior to the operation while the intervention group was administered 5 mL·kg⁻¹ of normal saline 2 hours before anesthesia. Hemodynamic indicators, diagnostic biomarkers, preoperative mini-mental status scores, and intraoperative fluid dynamics were recorded at baseline and at various postoperative timepoints. Subjects were then scored for POD and postoperative pain.

Results

S100β protein was lowered in S₁ (F_S1 = 12.289, P <0.001) and S₂ (F_S2 = 12.440, P <0.001) in the intervention group while mean arterial blood pressure (F_T1= 42.997, P<0.001) and heart rate (F_T1= 8.974, P=0.004) were increased. The Ln c-reactive protein of the intervention group was lowered 1 day postoperatively (F_S2 = 6.305, P = 0.014). The incidence of postoperative delirium in the control group was higher than in the intervention group (27.8% vs 8.3%, χ² = 4.547, P = 0.033).

Conclusion

Preoperative oral saline can reduce the incidence of postoperative delirium in older persons by minimizing perioperative hemodynamic fluctuations and central nervous system damage.

Automated machine learning-based model for the prediction of delirium in patients after surgery for degenerative spinal disease

OBJECTIVE

This study used machine learning algorithms to identify critical variables and predict postoperative delirium (POD) in patients with degenerative spinal disease.

METHODS

We included 663 patients who underwent surgery for degenerative spinal disease and received general anesthesia. The LASSO method was used to screen essential features associated with POD. Clinical characteristics, preoperative laboratory parameters, and intraoperative variables were reviewed and were used to construct nine machine learning models including a training set and validation set (80% of participants), and were then evaluated in the rest of the study sample (20% of participants). The area under the receiver-operating characteristic curve (AUROC) and Brier scores were used to compare the prediction performances of different models. The eXtreme Gradient Boosting algorithms (XGBOOST) model was used to predict POD. The SHapley Additive exPlanations (SHAP) package was used to interpret the XGBOOST model. Data of 49 patients were prospectively collected for model validation.

RESULTS

The XGBOOST model outperformed the other classifier models in the training set (area under the curve [AUC]: 92.8%, 95% confidence interval [CI]: 90.7%-95.0%), validation set (AUC: 87.0%, 95% CI: 80.7%-93.3%). This model also achieved the lowest Brier Score. Twelve vital variables, including age, serum albumin, the admission-to-surgery time interval, C-reactive protein level, hypertension, intraoperative blood loss, intraoperative minimum blood pressure, cardiovascular-cerebrovascular disease, smoking, alcohol consumption, pulmonary disease, and admission-intraoperative maximum blood pressure difference, were selected. The XGBOOST model performed well in the prospective cohort (accuracy: 85.71%).

CONCLUSION

A machine learning model and a web predictor for delirium after surgery for the degenerative spinal disease were successfully developed to demonstrate the extent of POD risk during the perioperative period, which could guide appropriate preventive measures for high-risk patients.

Impact of propofol versus sevoflurane on the incidence of postoperative delirium in elderly patients after spine surgery: study protocol of a randomized controlled trial

Background

Postoperative delirium in elderly patients is a common and costly complication after surgery. Propofol and sevoflurane are commonly used anesthetics during general anesthesia, and the sedative and anti-inflammatory mechanisms of the two medications are different. The aim of this trial is to compare the impact of propofol with sevoflurane on the incidence of postoperative delirium in elderly patients after spine surgery.

Methods

A single-center randomized controlled trial will be performed at First Affiliated Hospital of Shandong First Medical University, China. A total of 298 participants will be enrolled in the study and randomized to propofol infusion or sevoflurane inhalation groups. The primary outcome is the incidence of delirium within 7 days after surgery. Secondary outcomes include the day of postoperative delirium onset, duration (time from first to last delirium-positive day), and total delirium-positive days among patients who developed delirium; tracheal intubation time in PACU; the length of stay in PACU; the rate of postoperative shivering; the rate of postoperative nausea and vomiting; the rate of emergence agitation; pain severity; QoR40 at the first day after surgery; the length of stay in hospital after surgery; and the incidence of non-delirium complications within 30 days after surgery.

Discussion

The primary objective of this study is to compare the impact of propofol and sevoflurane on the incidence of postoperative delirium for elderly patients undergoing spine surgery. The results may help inform strategies to the optimal selection of maintenance drugs for general anesthesia in elderly patients undergoing spine surgery.

Trial registration

ClinicalTrials.govNCT05158998. Registered on 14 December 2021

Risk factors for postoperative delirium in geriatric patients with hip fracture: A systematic review and meta-analysis

Objectives

This systematic review and meta-analysis was conducted to identify the potential risk factors for postoperative delirium in geriatric patients with hip fracture.

Methods

PubMed, EMBASE, and Cochrane Library were searched from inception until December 31st, 2021. A combined searching strategy of subject words and free words was adopted. Studies involving risk factors for postoperative delirium in elderly patients undergoing hip fracture surgeries were reviewed. Qualities of included studies were assessed using the Newcastle–Ottawa Scale. Data were pooled and a meta-analysis was performed using Review Manager 5.3.

Results

A total of 37 studies were included. The following risk factors were significant: advanced age (per year increase) (OR: 1.05, 95% CI 1.04–1.07), age>80 years (OR: 2.26, 95% CI 1.47–3.47), male (OR: 1.53, 95% CI 1.37–1.70), preoperative cognitive impairment (OR:3.20, 95% CI 2.12–4.83), preoperative dementia (OR: 2.74, 95% CI 2.18–3.45), preoperative delirium (OR: 9.23, 95% CI 8.26–10.32), diabetes (OR: 1.18, 95% CI 1.05–1.33), preoperative functional dependence (OR: 1.31, 95% CI 1.11–1.56), ASA level (per level increase) (OR: 1.63, 95% CI 1.04–2.57), ASA level≥3(OR: 1.76, 95% CI 1.39–2.24), low albumin (OR: 3.30, 95% CI 1.44–7.55), medical comorbidities (OR: 1.15, 95% CI 1.06–1.25), Parkinson's disease (OR: 4.17, 95% CI 1.68–10.31) and surgery delay>48 h (OR: 1.90, 95% CI 1.36–2.65).

Conclusions

Clinicians should be alert to patients with those risk factors. To identify the risk factors more precisely, more research studies with larger sample size and better design should be conducted.

Risk Factors of Postoperative Delirium in Older Adult Spine Surgery Patients: A Meta-Analysis

This literature review identifies factors that may place older adult patients at risk for developing delirium after spine surgery. We conducted a meta-analysis according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Using a variety of electronic databases, we identified five studies for inclusion that represent 645 patients who were 65 years or older. The pooled incidence rate of postoperative delirium was 13.0%. Factors associated with developing postoperative delirium included preoperative opioid use, cervical spine surgery versus lumbar or thoracic spine surgery, spine fusion versus simple spine surgery, hypertension, cerebrovascular disease, pulmonary disease, duration of surgery, and infused IV fluid volume. Nurses who provide perioperative care for older adult patients undergoing spine surgery should be aware of the potential risk factors of delirium to ensure patient safety. Further research is required to clearly delineate the risk factors for postoperative delirium in older adults.

Impact of Tobacco Smoking on Outcomes After Posterior Decompression Surgery in Patients With Cervical Spondylotic Myelopathy: A Retrospective Multicenter Study

STUDY DESIGN

This was a case-control study.

OBJECTIVE

The objective of this study was to clarify the surgical outcomes after cervical posterior decompression in patients who smoked.

SUMMARY OF BACKGROUND DATA

Smoking is associated with poor outcomes in the field of spinal surgery. However, the impact of tobacco smoking on the outcomes after posterior decompression surgery has not been fully evaluated in patients with cervical spondylotic myelopathy.

MATERIALS AND METHODS

In this retrospective multicenter study, 587 patients with cervical spondylotic myelopathy were enrolled at 17 institutions in Japan. Patients underwent cervical laminoplasty or laminectomy and were followed up for at least 1 year after surgery. Outcome measures were: preoperative smoking status, perioperative complications, the Japanese Orthopedic Association scale, and the Visual Analog Scale for neck pain. After adjusting for age and sex by exact matching, smoking and nonsmoking groups were compared using an unpaired t test for continuous variables or a χ test for categorical variables.

RESULTS

There were 182 (31%) current smokers and 405 (69%) nonsmokers including previous smokers. After matching, 158 patients were extracted from each group. Demographic data and surgical information were almost the same between the groups. Regarding postoperative complications, there was no significant difference in the rate of surgical site infection, cerebrospinal fluid leakage, hematoma, segmental motor paralysis, or neurological deficit. However, smokers showed a significantly higher risk for delirium (3.8% vs. 0.0%, P=0.039). Smokers and nonsmokers showed comparable changes in functional recovery according to Japanese Orthopedic Association scores (3.2±2.1 vs. 3.0±2.1, P=0.425) and in neck pain reduction using the Visual Analog Scale (-1.7±3.1 vs. -1.4±2.8, P=0.417) at the final follow-up.

CONCLUSIONS

Smokers exhibited functional restoration and neck pain reduction after cervical posterior decompression. Attention is required, however, for the postoperative complication of delirium, which could be caused by the acute cessation of tobacco smoking after admission.

LEVEL OF EVIDENCE

Level III.

Systematic review and meta-analysis of risk factor for postoperative delirium following spinal surgery

Background

Postoperative delirium is a common psychiatric disorder among patients who undergo spinal surgery. The purpose of current meta-analysis was to assess the potential risk factors related to delirium in spinal surgery.

Methods

We searched the following databases: PubMed, EMBASE, the Cochrane Library, and Web of Science, from inception to July 2020. Two reviewers independently assessed the quality of the included studies using the previously described Newcastle-Ottawa Scale (NOS). We included spinal surgery patients who suffered with delirium or not. Stata 12.0 was used for meta-analysis.

Results

Thirteen trial studies that met our inclusion criteria were incorporated into the meta-analysis. Postoperative delirium was associated with an increase of the duration of hospital stay (P = 0.044) and increased perioperative readmission rate (P = 0.013) and economic costs (P = 0.002). This meta-analysis demonstrates that there were twenty-two risk factors: general characteristic: old age, female patients, history of surgery, diabetes mellitus, hypertension; preoperative data: low hematocrit, low hemoglobin, low albumin, low sodium, depression; operative data: operating time, total blood loss; postoperative data: low sodium, low hemoglobin, low hematocrit, low albumin, fever, low potassium, blood sugar, and visual analog scale (VAS).

Conclusions

Delirium not only prolongs the length of hospital stay, but also increases readmission rate and the economic costs. Several risk factors including old age, female patients, history of surgery, diabetes mellitus, low hematocrit, low hemoglobin, low albumin, low sodium, depression; operative data: operating time, total blood loss, low sodium, low hemoglobin, low hematocrit, low albumin, fever, low potassium, blood sugar, and VAS were significant predictors for postoperative delirium after spinal surgery.

Preoperative risk factors for delirium in patients aged ≥75 years undergoing spinal surgery: a retrospective study

OBJECTIVE

The increasing number of spinal surgeries being performed in the elderly has increased the incidence of postoperative delirium. The prediction of delirium is complex, and few studies have been performed to examine the preoperative risk factors for delirium after spinal surgery in the elderly. This study was performed to clarify such risk factors in patients aged ≥75 years undergoing spinal surgery.

METHOD

This retrospective observational study included 299 patients aged ≥75 years. Comorbidities, medication history, preoperative examination findings, surgery-related characteristics, and health scale assessments, including the 36-Item Short-Form Survey (SF-36) score and prognostic nutritional index (PNI), were examined as potential risk factors for delirium.

RESULTS

Delirium occurred in 53 patients (17.7%). The preoperative risk factors for delirium were a history of stroke and mental disorders, hypnotic drug use, malnutrition, hyponatremia, anemia, respiratory dysfunction, and cervical surgery. Logistic regression analysis demonstrated that the independent predictors of delirium were a history of stroke, non-benzodiazepine hypnotic drug use, preoperative hyponatremia, the PNI, and the SF-36 physical component summary (PCS) score.

CONCLUSIONS

Independent preoperative predictors of delirium in elderly patients undergoing spinal surgery included a history of stroke, non-benzodiazepine hypnotic drug use, preoperative hyponatremia, the PNI, and the SF-36 PCS score.

Risk factors for postoperative delirium after spinal surgery: a systematic review and meta-analysis

BACKGROUND

Postoperative delirium is common in older patients after spinal surgery. Many reports investigating the risk factors for delirium after spinal surgery have been published recently.

METHODS

A literature search was performed using the Cochrane Library, Web of Science, PubMed, Embase, and Springer databases from inception to February 2019. Relevant studies involving patients with delirium who underwent spinal surgery were included if the studies contained data about blood transfusion or other related factors, such as haemoglobin, haematocrit, and blood loss levels. The Newcastle-Ottawa Scale was used for the study-quality evaluation. The pooled odds ratios or (standard) mean differences of the individual risk factors were estimated using the Mantel-Haenszel or inverse-variance methods.

RESULTS

Fifteen observational studies met the inclusion criteria; the studies included a total of 583,290 patients (5431 patients with delirium and 577,859 patients without delirium). In addition to an advanced age, the results of the meta-analyses showed that living in an institution, diabetes, cerebral vascular diseases, pulmonary diseases, opioid use, length of surgery, intraoperative blood loss, blood transfusions, intraoperative infusion, preoperative albumin, postoperative albumin, preoperative haematocrit, postoperative haematocrit, preoperative haemoglobin, postoperative haemoglobin, preoperative sodium, postoperative sodium, Mini-Mental State Examination score, inability to ambulate, depression, number of medications, and treatment with multiple drugs (> three types) were significantly associated with delirium.

CONCLUSION

The above-mentioned risk factors can be used to identify high-risk patients, and the appropriate prophylaxis strategies should be implemented to prevent delirium after spinal surgery.

Incidence & Risk Factors of Postoperative Delirium After Spinal Surgery in Older Patients

Although postoperative delirium is a common complication in older patients, few papers have described risk factors after of spinal surgery. The purpose of this study was to analyze various perioperative risk factors for delirium after spinal surgery in older patients. This study was performed on retrospective data collection with prospective design. We analyzed 138 patients over 65 years of age who underwent spinal surgery. Preoperative factors were cognitive function (Mini-Mental State Examination-Korean (MMSE-K) and the Korean version of the Delirium Rating Scale-Revised-98 (K-DRS 98)), age, sex, type of admission, American Society of Anesthesiologist classification, metabolic equivalents, laboratory findings, visual analog scale, and Oswestry Disability Index. Intraoperative factors were operation time, blood loss, and type of procedure. Postoperative factors were blood transfusion and type of postoperative pain control. Postoperative delirium developed in 25 patients (18.16%). Patients were divided into two groups: Group with delirium (group A) and group without delirium (group B). MMSE-K scores in Group A were significantly lower than in Group B (p < 0.001). K-DRS 98 scores were significantly higher in Group A than Group B (p < 0.001). The operation time was longer in Group A than Group B (p = 0.059). On multivariate regression analysis, the odds ratio of K-DRS 98 was 2.43 (p = 0.010). After correction for the interaction between age and MMSE-K, patients younger than 73 years old had a significantly lower incidence of delirium with higher MMSE-K score (p = 0.0014). Older age, low level of preoperative cognitive function, long duration of surgery, and transfusion were important risk factors of postoperative delirium after spinal surgery. It is important to recognize perioperative risk factors and manage appropriately.

Postoperative delirium in patients undergoing surgery for bone metastases

Postoperative delirium (PD), characterized by acute onset of global impairment in consciousness and cognition, is a common complication following major surgeries and is often associated with adverse outcomes. Because of the multiple comorbidities of the patient along with extensive nature of the surgery, patients undergoing surgery for bone metastases may be prone to developing PD. However, no study exists regarding PD in patients who undergo surgery for bone metastases.Two hundred seventy six patients with mean age of 64 years (range, 16-94) who underwent surgery for bone metastases were reviewed. The diagnosis of PD was made by the psychiatrist, according to fourth edition of the Diagnostic and Statistical Manual of Mental Disorders. Possible perioperative clinic-pathologic factors that may be associated with the development of PD were investigated.Among the 276 patients, 9% (n = 25) developed PD. On multivariate logistic regression analysis, history of psychiatric disorders (odds ratio [OR] = 9.63; 95% confidence interval [CI] 1.78-21.74, P = .004), high preoperative serum C-reactive protein (CRP) level (OR = 1.17; 95% CI 1.06-1.29, P = .001), low preoperative serum albumin level (OR = 0.13; 95% CI 0.03-0.48, P = 0.002), and high dose of opioid analgesics received in the immediate postoperative period (OR = 1.05; 95% CI 1.01-1.07, P = .001) were independently associated with the development of PD. Patients with PD had lower survival (log rank, P = .001) than patients without PD.Incidence of PD is considerable in patients undergoing surgery for bone metastases. History of psychiatric disorders, preoperative serum albumin and CRP levels, and the dose of postoperative opioid analgesics are associated with the development of PD.

Prevalence and risk factors of postoperative delirium after spinal surgery: a meta-analysis

OBJECTIVE

Postoperative delirium (POD) was common after spinal surgery, but the main findings in previous studies remained conflicting. This current meta-analysis was aimed at exploring the prevalence and risk factors of POD after spinal surgery.

METHODS

PubMed and Embase were searched from inception to June 2019. Studies which reported the prevalence and risk factors of POD after spinal surgery were included. STATA version 12.0 was employed to analyze the pooled data. Statistical heterogeneity across included studies was identified using the I2 statistics.

RESULTS

A total of 28 studies with 588,732 patients were included in the meta-analysis. The pooled prevalence of POD after spinal surgery was 0.85% (95%CI, 0.83-0.88%) with substantial heterogeneity (I2 = 97.3%). The central nervous system disorder (OR 4.73; 95%CI, 4.30-5.19) was a strong predictor for POD, whereas age (OR 1.16; 95%CI, 1.05-2.47; I2 = 99.2%) and blood loss (OR 1.10; 95%CI, 1.01-1.20; I2 = 93.3%) were weaker predictors. The funnel plot and statistical tests suggested that there existed potential publication bias, but the trim and fill method indicated that the pooled prevalence basically kept stable after adding two "missing" studies.

CONCLUSIONS

The pooled POD after spinal surgery ranges from 0.83 to 0.88%. The central nervous system disorder, age, and blood loss were potential risk factors for POD.

Incidence and Risk Factors for Postoperative Delirium in Patients Undergoing Spine Surgery: A Systematic Review and Meta-Analysis

Background

The present study aims to investigate the incidence and risk factors associated with postoperative delirium in patients undergoing spine surgery.

Methods

PubMed, EMBASE, Cochrane Library, and Science Citation Index were searched up to August 2019 for studies examining postoperative delirium following spine surgery. Incidence and risk factors associated with delirium were extracted. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for outcomes. The Newcastle-Ottawa Scale (NOS) was used for the study quality evaluation.

Results

The final analysis includes a total of 40 studies. The pooled analysis reveals that incidence of delirium is 8%, and there are significant differences for developing delirium in age (OR 1.07; 95% CI 1.04-1.09), age more than 65 (OR 4.77; 95% CI 4.37-5.16), age more than 70 (OR 15.87; 95% CI 6.03-41.73), and age more than 80 (OR 1.91; 95% CI 1.78-2.03) years, male (OR 0.81; 95% CI 0.76-0.86), a history of alcohol abuse (OR 2.11; 95% CI 1.67-2.56), anxiety (OR 1.74; 95% CI 1.04-2.44), congestive heart failure (OR 1.4; 95% CI 1.21-1.6), depression (OR 2.5; 95% CI 1.52-3.49), hypertension (OR 1.12; 95% CI 1.04-1.2), kidney disease (OR 1.41; 95% CI 1.16-1.66), neurological disorder (OR 4.66; 95% CI 4.22-5.11), opioid use (OR 1.86; 95% CI 1.18-2.54), psychoses (OR 2.77; 95% CI 2.29-3.25), pulmonary disease (OR 1.81; 95% CI 1.27-2.35), higher mini-mental state examination (OR 0.7; 95% CI 0.5-0.89), preoperative pain (OR 1.88; 95% CI 1.11-2.64), and postoperative urinary tract infection (OR 5.68; 95% CI 2.41-13.39).

Conclusions

A comprehensive understanding of incidence and risk factors of delirium can improve prevention, diagnosis, and management. Risk of postoperative delirium can be reduced based upon identifiable risk factors.

Serum biomarkers of delirium in the elderly: a narrative review

Delirium after surgery and in the intensive care unit (ICU) remains a challenge for patients, families, and caregivers. Over the years, many promising biomarkers have been investigated as potential instruments for risk stratification of delirium. This review aimed to identify and assess the clinical usefulness of candidate serum biomarkers associated with hospital delirium in patients aged 60 years and older. We performed a time-unlimited review of publications indexed in PubMed, Cochrane, Embase, and MEDLINE databases until June 2019 that evaluated baseline and/or longitudinal biomarker measurements in patients suffering from delirium at some point during their hospital stay. A total of 32 studies were included in this review reporting information on 7610 patients. Of these 32 studies, twenty-four studies reported data from surgical patients including four studies in ICU cohorts, five studies reported data from medical patients (1026 patients), and three studies reported data from a mixed cohort (1086 patients), including one study in an ICU cohort. Findings confirm restricted clinical usefulness to predict or diagnose delirium due to limited evidence on which biomarkers can be used and limited availability due to non-routine use.

The risk factors associated with delirium after lumbar spine surgery in elderly patients

Background

To prospectively explore the incidence and risk factors for postoperative delirium in elderly patients following lumbar spine surgery.

Methods

This prospective study enrolled 148 consecutive patients over the age of 65 who were scheduled to undergo spine surgery. Patients were screened for delirium using the short Confusion Assessment Method (CAM) postoperatively. Patient demographics and relevant medical information were collected. Logistic regression analysis was used to identify the risk factors associated with postoperative delirium.

Results

Eighty-three patients (56.1%) who underwent lumbar spine surgery (not coexisting with cervical or thoracic spine surgery) were enrolled in our study. Post-operative delirium was noted in 14.5% of patients over 65 years old. The presence of preoperative Parkinsonism was significantly higher in the delirium group (41.7% vs. 8.5%, P=0.002), as was a higher preoperative C-reactive protein (CRP) (7.0±15.2 vs. 1.3±2.3 mg/L, P=0.017) when compared with the non-delirium group. Of the risk factors, male sex [odds ratio (OR) =0.10, 95% confidence interval (CI): 0.01-0.66, P=0.017], Parkinsonism (OR =5.83, 95% CI: 1.03-32.89, P=0.046), and lower baseline MMSE score (OR =0.71, 95% CI: 0.52-0.97, P=0.032) were independently associated with postoperative delirium in elderly patients undergoing lumbar spine surgery.

Conclusions

Post-operative delirium occurred in 14.5% of elderly patients who underwent lumbar spine surgery. Male sex, Parkinsonism, and lower baseline MMSE score were identified as independent risk factors for postoperative delirium in elderly patients following lumbar surgery.

Intraoperative ketamine may increase risk of post-operative delirium after complex spinal fusion for adult deformity correction

BACKGROUND

For complex surgery, intraoperative ketamine administration is readily used to reduce post-operative pain. However, there have been a few studies suggesting that intraoperative ketamine may have deleterious effects and impact post-operative delirium. Therefore, we sought to identify the impact that intraoperative ketamine has on post-operative outcomes after complex spinal surgery involving ≥5 level fusions.

METHODS

The medical records of 138 adult (≥18 years old) spine deformity patients undergoing elective, primary complex spinal fusion (≥5 level) for deformity correction at a major academic institution from 2010 to 2015 were reviewed. We identified 98 (71.0%) who had intraoperative ketamine administration and 40 (29%) who did not (Ketamine-Use: n=98; No-Ketamine: n=40). Patient demographics, comorbidities, intra- and post-operative complication rates were collected for each patient. The primary outcome investigated in this study was the rate of post-operative delirium. A multivariate nominal-logistic regression analysis was used to determine the independent association between intraoperative ketamine and post-operative delirium.

RESULTS

Patient demographics and comorbidities were similar between both cohorts, including age, gender, and BMI. The median number of fusion levels operated, length of surgery, estimated blood loss, and proportion of patients requiring blood transfusions were similar between both cohorts. Postoperative complication profile was similar between the cohorts, except for the Ketamine-Use cohort having significantly higher proportion of patients experiencing delirium (Ketamine-Use: 14.3% vs. No-Ketamine: 2.6%, P=0.047). In a multivariate nominal-logistic regression analysis, intraoperative Ketamine-Use was independently associated with post-operative delirium (OR: 9.475, 95% CI: 1.026-87.508, P=0.047).

CONCLUSIONS

Our study suggests that the intraoperative use of ketamine may increase the risk of post-operative delirium. Further studies are necessary to understand the physiological effect intraoperative ketamine has on patients undergoing complex spinal fusions in order to better overall patient care and reduce healthcare resources.

SF-36 scores predict postoperative delirium after surgery for cervical spondylotic myelopathy

OBJECTIVE

Cervical spondylotic myelopathy (CSM) is one of the most common causes of spinal cord dysfunction. Surgery for CSM is generally effective, but postoperative delirium is a potential complication. Although there have been some studies that investigated postoperative delirium after spine surgery, no useful tool for identifying high-risk patients has been established, and it is unknown if 36-Item Short Form Health Survey (SF-36) scores can predict postoperative delirium. The objective of this study was to evaluate the correlation between preoperative SF-36 scores and postoperative delirium after surgery for CSM.

METHODS

Sixty-seven patients who underwent surgery for CSM at the authors' institution were enrolled in this study. Medical records of these patients were retrospectively reviewed. Patient background, preoperative laboratory data, preoperative SF-36 scores, the preoperative Japanese Orthopaedic Association (JOA) score for the evaluation of cervical myelopathy, and perioperative factors were selected as potential risk factors for postoperative delirium. These factors were evaluated using univariable and multivariable logistic regression analysis.

RESULTS

Ten patients were diagnosed with postoperative delirium. Univariable analysis revealed that the physical functioning score (p = 0.01), general health perception score (p < 0.01), and vitality score (p < 0.01) of the SF-36 were significantly lower in patients with postoperative delirium than in those without. The total number of medications was significantly higher in the delirium group compared with the no-delirium group (p = 0.02). In contrast, there were no significant differences between the delirium group and the no-delirium group in cervical JOA scores (p = 0.20). Multivariable analysis revealed that a low general health perception score was an independent risk factor for postoperative delirium (p = 0.02; odds ratio 0.810, 95% confidence interval 0.684-0.960).

CONCLUSIONS

Some of the SF-36 scores were significantly lower in patients with postoperative delirium than in those without. In particular, the general health perception score was independently correlated with postoperative delirium. SF-36 scores could help identify patients at high risk for postoperative delirium and aid in the development of prevention strategies.

Association Between Transfusion of RBCs and Subsequent Development of Delirium in Critically Ill Children

OBJECTIVES

To determine the temporal relationship between the transfusion of RBCs and the subsequent development of delirium in a cohort of critically ill children.

DESIGN

Nested retrospective cohort study within prospective cohort study.

SETTING

Urban academic tertiary care PICU.

PATIENTS

All consecutive admissions from September 2014 through August 2015.

INTERVENTIONS

Children were screened twice daily for delirium during their PICU admission.

MEASUREMENTS AND MAIN RESULTS

Among 1,547 independent admissions screened for delirium, 166 (10.7%) were transfused RBCs. Children who were transfused RBCs were more than twice as likely to be delirious during their admission compared with children who were never transfused, after controlling for known predictors of delirium development (adjusted odds ratio, 2.16; 95% CI, 1.38-3.37; p = 0.001). Among transfused children, a temporal relationship was observed between receipt of RBCs and the subsequent development of delirium. For each additional 10 mL/kg of RBCs transfused, the recipients were 90% more likely to develop delirium or coma in the 72 hours following the transfusion, after controlling for confounders (adjusted odds ratio, 1.90; 95% CI, 1.14-3.17; p = 0.01). Anemia (represented by nadir hemoglobin prior to transfusion) was not associated with delirium development.

CONCLUSIONS

In this cohort of critically ill children, there is an independent association between the receipt of an RBC transfusion and the subsequent development of delirium. Further prospective studies are warranted to replicate this finding and investigate possible pathophysiologic mechanisms for this association.

Preoperative severe hypoalbuminemia is associated with an increased risk of postoperative delirium in elderly patients: Results of a secondary analysis

PURPOSE

To explore the association between the severity of preoperative hypoalbuminemia and the occurrence of postoperative delirium.

MATERIALS AND METHODS

This was a secondary analysis of the database from a previously conducted clinical trial. 700 elderly patients (age ≥65years) who were admitted to intensive care unit (ICU) after noncardiac surgery were included. Delirium was assessed with the Confusion Assessment Method for the ICU twice daily during the first 7days postoperatively. Other outcomes were also monitored. The relationship between preoperative albumin level and postoperative delirium were analyzed using a logistic regression model.

RESULTS

111 of 700 patients (15.9%) developed postoperative delirium. When compared with normal albumin level (>40.0g/L), severe (≤30.0g/L: OR 2.727, 95% CI 1.283-5.797, P=0.009), but not mild (35.1-40.0g/L: OR 1.175, 95% CI 0.679-2.032, P=0.565) or moderate (30.1-35.0g/L: OR 1.674, 95% CI 0.897-3.122, P=0.105) hypoalbuminemia was associated with an increased risk of postoperative delirium. Preoperative severe hypoalbuminemia was also associated with prolonged mechanical ventilation, increased non-delirium complications, and prolonged ICU and hospital stay after surgery.

CONCLUSIONS

Preoperative severe hypoalbuminemia (≤30.0g/L) was associated with an increased risk of postoperative delirium and worse outcomes.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, www.chictr.org.cn, ChiCTR-TRC-10000802.

Risk Factors for Delirium After Spine Surgery in Extremely Elderly Patients Aged 80 Years or Older and Review of the Literature: Japan Association of Spine Surgeons with Ambition Multicenter Study

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

Spine surgeries in elderly patients have increased in recent years due to aging of society and recent advances in surgical techniques, and postoperative complications have become more of a concern. Postoperative delirium is a common complication in elderly patients that impairs recovery and increases morbidity and mortality. The objective of the study was to analyze postoperative delirium associated with spine surgery in patients aged 80 years or older with cervical, thoracic, and lumbar lesions.

METHODS

A retrospective multicenter study was performed in 262 patients 80 years of age or older who underwent spine surgeries at 35 facilities. Postoperative complications, incidence of postoperative delirium, and hazard ratios of patient-specific and surgical risk factors were examined.

RESULTS

Postoperative complications occurred in 59 of the 262 spine surgeries (23%). Postoperative delirium was the most frequent complication, occurring in 15 of 262 patients (5.7%), and was significantly associated with hypertension, cerebrovascular disease, cervical lesion surgery, and greater estimated blood loss (P < .05). In multivariate logistic regression using perioperative factors, cervical lesion surgery (odds ratio = 4.27, P < .05) and estimated blood loss ≥300 mL (odds ratio = 4.52, P < .05) were significantly associated with postoperative delirium.

CONCLUSIONS

Cervical lesion surgery and greater blood loss were perioperative risk factors for delirium in extremely elderly patients after spine surgery. Hypertension and cerebrovascular disease were significant risk factors for postoperative delirium, and careful management is required for patients with such risk factors.

Prevention and Management of Postoperative Delirium in Elderly Patients Following Elective Spinal Surgery

STUDY DESIGN

This study is a systematic review.

OBJECTIVE

Propose an evidence-based algorithm for prevention, diagnosis, and management of postoperative delirium in geriatric patients undergoing elective spine surgery.

SUMMARY OF BACKGROUND DATA

Delirium is associated with longer stays after elective surgery, increased risk of readmission, and $6.9 billion annually in medical costs. Early diagnosis and treatment of delirium can reduce length of stay (LOS), in-hospital morbidity, and health care costs. After spinal surgery, postoperative delirium increases average LOS to >7 days and is diagnosed in 12.5%-24.3% of geriatric patients. Currently, studies for management of postoperative delirium after elective spinal procedures are not available.

METHODS

A literature review was performed for observational studies, randomized controlled trials, and systematic reviews between 1990 and 2015.

RESULTS

Risk factors for delirium after elective spinal surgery include age, functional impairment, preexisting dementia, general anesthesia, surgical duration >3 hours, intraoperative hypercapnia and hypotension, greater blood loss, low hematocrit and albumin, preoperative affective dysfunction, and postoperative sleep disorders. Postoperatively, decreasing the use of methylprednisolone and promoting movement with an appropriate orthosis can reduce delirium incidence (P=0.0091). Polypharmacy is an independent risk factor for delirium (P=0.01) and decreasing use of delirium-inducing medications may reduce incidence. The delirium observation screening scale diagnoses and monitors delirium and is rated by nurses as easier to use than the NEECHAM Confusion Scale (P<0.003). Haloperidol is used widely to treat postoperative delirium. Randomized controlled trials show that adding quetiapine results in delirium resolution an average of 3.5 days faster than haloperidol alone (P=0.001) and decreases agitation and LOS (P=0.02; P=0.05).

CONCLUSIONS

An evidence-based algorithm is proposed to prevent, diagnose, and manage postoperative delirium that can be used clinically for geriatric patients undergoing elective spine surgery. Prevention and diagnosis involve efforts from the anesthesiologist and postoperative clinical care team. Treatment may include a therapeutic regimen of low-dose neuroleptic medications as needed.

LEVEL OF EVIDENCE

Level II.

The Effect of Treatment of Anemia with Blood Transfusion on Delirium: A Systematic Review

OBJECTIVES

Treating the precipitating factors of delirium is the mainstay of the prevention and treatment of delirium. We aim to investigate the role of anemia and blood transfusion within the multicomponent prevention and treatment strategy of delirium.

DESIGN

Systematic review.

SETTING

We included cohort studies or Randomized Controlled Trials (RCTs) that considered blood transfusion as treatment for delirium or risk factor, and had delirium as outcome.

PARTICIPANTS

Hospitalized patients above 55 years old.

MEASUREMENTS

We searched MEDLINE from 1946 through November 2014. Quality assessment and data extraction were performed systematically.

RESULTS

We included 23 studies (n = 29,471). The majority of the studies (n = 22) had a limited quality and for one study quality was uncertain. Two studies evaluated the association between transfusion strategy and postoperative delirium and found no association. Twenty-one studies investigated blood transfusion as a risk factor for delirium. In four of the 21 studies it could be assumed that delirium occurred after transfusion. One of these studies stated that transfusion was a significant risk factor for subsequent delirium (odds ratio (OR) = 3.68, 95% confidence interval (CI) = 1.32-10.94). The other three studies found no association between transfusion and delirium. In the remaining 17 studies, it was not clear whether delirium occurred before or after transfusion, so no conclusion could be drawn on the role of transfusion in delirium development.

CONCLUSION

The majority of the included studies was not suited to answer the research question properly as the time course of the beginning of delirium as to transfusion was lacking. Our review shows that there is no good quality evidence available for blood transfusion to be a risk factor for delirium or to be a preventive or treatment option.

Risk Factors for Delirium After Spinal Surgery: A Meta-Analysis

OBJECTIVE

Postoperative delirium can occur following various types of surgeries. The specific risk factors for delirium following spinal surgery have not been systematically evaluated. The aim of this study is to conduct a meta-analysis of the risk factors for delirium after spinal surgery.

METHODS

PubMed, EMBASE, the Cochrane Library, and Science Citation Index were searched from inception to October 2014 for original research studies. Relevant studies on patients with delirium following spinal surgery were included if they identified at least 1 risk factor as being associated with delirium. The Newcastle-Ottawa Scale (NOS) was used for the study quality assessment, and the pooled odds ratios (ORs) were used for determining the risk factors.

RESULTS

Six articles met the inclusion criteria. Twenty-four risk factors in the multivariate analyses and 22 factors in the univariate analyses were significantly associated with delirium following spinal surgery. In the pooled analyses, age >65 years (OR: 6.13; 95% confidence interval [CI]: 5.75, 6.54); female sex (OR: 1.21; 95% CI: 1.15, 1.28); number of medications (mean difference [MD]: 1.36; 95% CI: 0.73, 2.00); low preoperative hematocrit (MD: -1.67; 95% CI: -2.97, -0.38) and albumin (MD: -0.33; 95% CI: -0.53, -0.13); duration of surgery (MD: 35.79; 95% CI: 1.42, 70.16); intraoperative blood loss (MD: 124.44; 95% CI: 100.03, 148.85); low postoperative hematocrit (MD: -2.58; 95% CI: -3.70, -1.46), hemoglobin (MD: -1.10; 95% CI: -1.86, -0.35), and sodium (MD: -2.97; 95% CI: -5.42, -0.51); and postoperative fever (OR: 4.52; 95% CI: 2.94, 6.95) were significantly associated with delirium.

CONCLUSIONS

Several risk factors were consistently associated with delirium following spinal surgery, which can be used to identify high-risk patients. Recognizing these patients is important for physicians to develop preventive strategies to reduce postoperative delirium and its negative consequences.

Low hemoglobin level is associated with the development of delirium after hepatectomy for hepatocellular carcinoma patients

Background

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide and liver resection is the only potential curative treatment option for those patients. Postoperative complications specific to elderly surgical patients such as delirium will be increasingly relevant in the coming decades. Herein, we aimed to investigate the risk factors for postoperative delirium in patients who have received hepatectomy for HCC.

Methods

This is a single medical center observational study and the study subjects comprised 401 individuals who underwent liver resection for hepatocellular carcinoma during January 2009 to October 2013. Multivariate analysis was used to examine whether preoperative, intra-operative, or postoperative variables were associated with the development of delirium.

Results

Of the 401 patients who underwent hepatectomy, 34 developed postoperative delirium (8.4%). In the majority of those patients, symptoms and signs of the syndrome occurred on postoperative day 2 and the mean duration of symptoms was 3.61 ± 3.71 days. Multivariate analysis revealed that advanced age (>71 years) [odds ratio (OR) = 1.133, 95% confidence interval (CI): 1.071–1.200, p<0.001], prolonged operative time (>190 minutes) (OR = 1.009, 95% CI: 1.000–1.017, p = 0.038), a decreased postoperative hemoglobin level (< 10.16 g/dL) (OR = 0.777, 95% CI: 0.613–0.983, p = 0.036), and history of hypnotic drug use (OR = 3.074, 95% CI: 1.045–9.039, p = 0.041) were independent risk factors for the development of postoperative delirium after hepatectomy.

Conclusions

Although the mechanism of postoperative delirium is not well understood, numbers of studies have shown that patients with postoperative delirium tend to have prolonged hospital stay, worse postoperative outcome and an increased risk of short- and long-term mortality. In this study, we found that advanced age, prolonged operative time, postoperative low hemoglobin level and history of hypnotic drug use are independent risk factors for postoperative delirium.

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.

Risk factors for delirium after spine surgery in elderly patients

Objective

Postoperative delirium is a common complication in the elderly after surgery but few papers have reported after spinal surgery. We analyzed various risk factors for postoperative delirium after spine surgery.

Methods

Between May 2012 and September 2013, 70 patients over 60 years of age were examined. The patients were divided into two groups : Group A with delirium and Group B without delirium. Cognitive function was examined with the Mini-Mental State Examination-Korea (MMSE-K), Clinical Dementia Rating (CDR) and Global Deterioration Scale (GDS). Information was also obtained on the patients' education level, underlying diseases, duration of hospital stay and laboratory findings. Intraoperative assessment included Bispectral index (BIS), type of surgery or anesthesia, blood pressure, fluid balance, estimated blood loss and duration of surgery.

Results

Postoperative delirium developed in 17 patients. The preoperative scores for the MMSE, CDR, and GDS in Group A were 19.1±5.4, 0.9±0.6, and 3.3±1.1. These were significantly lower than those of Group B (25.6±3.4, 0.5±0.2, and 2.1±0.7) (p<0.05). BIS was lower in Group A (30.2±6.8 compared to 35.4±5.6 in group B) (p<0.05). The number of BIS <40 were 5.1±3.1 times in Group A, 2.5±2.2 times in Group B (p<0.01). In addition, longer operation time and longer hospital stay were risk factors.

Conclusion

Precise analysis of risk factors for postoperative delirium seems to be more important in spinal surgery because the surgery is not usually expected to have an effect on brain function. Although no risk factors specific to spinal surgery were identified, the BIS may represent a valuable new intraoperative predictor of the risk of delirium.

Onset, risk factors, and impact of delirium in patients with traumatic spinal cord injury

Delirium is a commonly reported acute care adverse event in patients with traumatic spinal cord injury (TSCI), but studies specifically investigating it in this population are lacking. The purpose of this study was to characterize the onset, risk factors, and impact of delirium in patients with TSCI. Patients discharged between 2008 and 2010 were identified from a prospective registry in an acute SCI center. Controls were matched to delirium cases based on date of discharge from acute care. Patient characteristics, risk factors, and the hospital unit (intensive care, spine step-down, spine ward) in which delirium occurred were collected retrospectively. Length of stay (LOS) was calculated and compared between cases and controls. A predictive model was built for patient characteristics and risk factors associated with delirium using logistical regression. There were 192 patients identified from the study group; 34 (17.7%) were delirium cases and 34 were selected as controls. Most delirious episodes were reported during high acuity care (76.5%). The median time interval between injury and delirium identification was 8.5 days (interquartile range=5-31). Age at injury (p<0.01) and initial motor score (p<0.05) were significantly associated with delirium. Patients with delirium had significantly greater LOS than controls (median LOS=46.9 vs. 15.3 days respectively, p<0.0001). Elderly patients who sustain a TSCI and have a low motor score on admission are at increased risk of delirium. These results could contribute to the development of a screening program to address the problem of delirium in the TSCI population.

Association between intraoperative blood transfusions and early postoperative delirium in older adults

OBJECTIVES

To determine whether intraoperative blood transfusion, a known trigger and amplifier of inflammation, is an independent risk factor for early postoperative delirium (POD), an acute state of confusion with fluctuating consciousness and inattention after surgery, in older adults undergoing surgery.

DESIGN

Secondary analysis using a database created for a prospective cognitive outcomes study.

SETTING

University hospital.

PARTICIPANTS

Four hundred seventy-two individuals aged 65 and older undergoing major noncardiac surgery.

MEASUREMENTS

Perioperative data were examined for association with POD on the first postoperative day. Multivariable logistic regression analysis was conducted to determine whether intraoperative blood transfusion independently predicts POD after adjusting for covariates known to be associated with onset of delirium and blood transfusions.

RESULTS

One hundred thirty-seven individuals (29%) developed delirium on the first postoperative day. The multivariable logistic regression model identified age, sex, history of central nervous system disorder, preoperative cognitive dysfunction, and pain, as well as blood transfusions, as independent risk factors for POD. Intraoperative administration of more than 1,000 mL of red blood cells (RBCs) was the strongest predictor of POD on the first postoperative day (odds ratio = 3.68; 95% confidence interval = 1.32–10.94; P < .001).

CONCLUSION

Intraoperative blood transfusion of more than 1,000 mL of RBCs increases the risk of delirium on the first postoperative day in older adults undergoing noncardiac surgery.