Pain, Opioid Intake, and Delirium Symptoms in Adults Following Joint Replacement Surgery

Postoperative pain and neurocognitive outcomes after noncardiac surgery: a systematic review and dose-response meta-analysis

BACKGROUND

Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are common after noncardiac surgery. Postsurgical pain is frequent and can persist as chronic postsurgical pain (CPSP). The association between postsurgical pain and POD or POCD is biologically plausible. We conducted this systematic review to evaluate the association between acute postsurgical pain or CPSP and POD or POCD in adults undergoing noncardiac surgery.

METHODS

We followed Preferred Reporting Items for Systematic Review and Meta-Analyses. We searched MEDLINE, EMBASE, Cochrane, CINAHL and PSYCHINFO up to May 2023. We included cohort, case-control, and cross-sectional studies of any language. Pairs of reviewers independently screened studies, extracted data and assessed the risk of bias using the CLARITY tool and the Joanna Briggs Institute checklist. We assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. Where possible, we conducted random-effects meta-analyses to summarise our findings.

RESULTS

We analysed 30 studies (>9000 participants) that assessed the association between acute postoperative pain and POD/POCD. Dose-response meta-analyses found that postoperative pain intensity was associated with occurrence of POD (adjusted relative risk [aRR]/unit of pain intensity: 1.26; 95% confidence interval [CI]: 1.17-1.35; low certainty of evidence) and risk of developing POD (aRR/unit of pain intensity: 1.18; 95% CI: 1.08-1.30; low certainty of evidence). There was very low certainty of evidence regarding the association between postoperative pain and POCD. No studies assessed the association between CPSP and POCD. Residual confounding and substantial methodological variability between studies prevented pooling data from many of the included studies and lowered certainty of evidence.

CONCLUSIONS

Dose-response meta-analyses found that postoperative pain intensity was associated with occurrence of and risk of developing POD.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO-CRD42021192105.

Assessment and report of individual symptoms in studies of delirium in postoperative populations: a systematic review

OBJECTIVES

Delirium is most often reported as present or absent. Patients with symptoms falling short of the diagnostic criteria for delirium fall into 'no delirium' or 'control' groups. This binary classification neglects individual symptoms and may be hindering identification of the pathophysiology underlying delirium. This systematic review investigates which individual symptoms of delirium are reported by studies of postoperative delirium in adults.

METHODS

Medline, EMBASE and Web of Science databases were searched on 03 June 2021 and 06 April 2023. Two reviewers independently examined titles and abstracts. Each paper was screened in duplicate and conflicting decisions settled by consensus discussion. Data were extracted, qualitatively synthesised and narratively reported. All included studies were quality assessed.

RESULTS

These searches yielded 4,367 results. After title and abstract screening, 694 full-text studies were reviewed, and 62 deemed eligible for inclusion. This review details 11,377 patients including 2,049 patients with delirium. In total, 78 differently described delirium symptoms were reported. The most reported symptoms were inattention (N = 29), disorientation (N = 27), psychomotor agitation/retardation (N = 22), hallucination (N = 22) and memory impairment (N = 18). Notably, psychomotor agitation and hallucinations are not listed in the current Diagnostic and Statistical Manual for Mental Disorders-5-Text Revision delirium definition.

CONCLUSIONS

The 78 symptoms reported in this systematic review cover domains of attention, awareness, disorientation and other cognitive changes. There is a lack of standardisation of terms, and many recorded symptoms are synonyms of each other. This systematic review provides a library of individual delirium symptoms, which may be used to inform future reporting.

Prevalence and risk factors of subsyndromal delirium among postoperative patients: A systematic review and meta-analysis

AIM

The aim of this study is to determine the prevalence and risk factors for subsyndromal delirium in the postoperative patient.

DESIGN

A systematic review and meta-analysis.

METHODS

The Review Manager 5.3 statistics platform and the Newcastle-Ottawa Scale were used for quality evaluation.

DATA SOURCES

The following databases were searched: PubMed, Web of Science, EMBASE, The Cochrane Library, Scopus and EBSCO from January 2000 to December 2021. Additional sources were found by looking at relevant articles' citations.

RESULTS

A total of 1744 titles were originally identified, and five studies including 962 patients were included in the systematic review, with a pooled prevalence of postoperative subsyndromal delirium (PSSD) of 30% (95% CI: 0.28-0.32). Significant risk variables for PSSD were older age, low levels of education (≤9 years), cognitive impairment, higher comorbidity score, and the duration of operation.

CONCLUSION

PSSD is prevalent and is associated with a variety of risk factors as well as low academic performance.

IMPACT

Identification and clinical management of patients with PSSD should be improved. Future research on PSSD risk factors should look at a wider range of intraoperative and postoperative risk factors that can be changed.

PATIENT AND PUBLIC CONTRIBUTION

No Patient or Public Contribution.

Relationship Between Pain and Delirium in Critically Ill Adults

OBJECTIVES

Although opioids are frequently used to treat pain, and are an important risk for ICU delirium, the association between ICU pain itself and delirium remains unclear. We sought to evaluate the relationship between ICU pain and delirium.

DESIGN

Prospective cohort study.

SETTING

A 32-bed academic medical-surgical ICU.

PATIENTS

Critically ill adults (n = 4,064) admitted greater than or equal to 24 hours without a condition hampering delirium assessment.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Daily mental status was classified as arousable without delirium, delirium, or unarousable. Pain was assessed six times daily in arousable patients using a 0-10 Numeric Rating Scale (NRS) or the Critical Care Pain Observation Tool (CPOT); daily peak pain score was categorized as no (NRS = 0/CPOT = 0), mild (NRS = 1-3/CPOT = 1-2), moderate (NRS = 4-6/CPOT = 3-4), or severe (NRS = 7-10/CPOT = 5-8) pain. To address missingness, a Multiple Imputation by Chained Equations approach that used available daily pain severity and 19 pain predictors was used to generate 25 complete datasets. Using a first-order Markov model with a multinomial logistic regression analysis, that controlled for 11 baseline/daily delirium risk factors and considered the competing risks of unarousability and ICU discharge/death, the association between peak daily pain and next-day delirium in each complete dataset was evaluated.

RESULTS

Among 14,013 ICU days (contributed by 4,064 adults), delirium occurred on 2,749 (19.6%). After pain severity imputation on 1,818 ICU days, mild, moderate, and severe pain were detected on 2,712 (34.1%), 1,682 (21.1%), and 894 (11.2%) of the no-delirium days, respectively, and 992 (36.1%), 513 (18.6%), and 27 (10.1%) of delirium days (p = 0.01). The presence of any pain (mild, moderate, or severe) was not associated with a transition from awake without delirium to delirium (aOR 0.96; 95% CI, 0.76-1.21). This association was similar when days with only mild, moderate, or severe pain were considered. All results were stable after controlling for daily opioid dose.

CONCLUSIONS

After controlling for multiple delirium risk factors, including daily opioid use, pain may not be a risk factor for delirium in the ICU. Future prospective research is required.

Grip Strength is a Predictor for Subsyndromal Delirium Among Older Adults Following Joint Replacement

Background

Delirium is common in older patients during the postoperative period, increasing the number of adverse events, and grip strength is associated with delirium. Subsyndromal delirium (SSD) is a prostate of clinical delirium; nevertheless, the relationship between grip strength and SSD has not been elucidated. This study aimed to examine the association between grip strength and SSD in the elderly after arthroplasty.

Methods

A total of 181 patients were recruited from two Chinese hospitals. SSD and delirium were evaluated before the surgery and the first week after surgery using the confusion assessment method. The Mini-mental State Examination was used to assess patients' cognitive function, and their grip strength was evaluated with an electronic hand dynamometer before surgery. Logistic regression and ROC curve analysis were conducted to determine the odds ratio and predictive value of grip strength for SSD.

Results

The incidence of SSD and postoperative delirium (POD) was 41.44% and 14.36% for the elderly following arthroplasty respectively, and approximately 1/3 of SSD progressed into POD. Older age, declined cognitive function, fall history, and lower grip strength were risk factors for SSD (P<0.05). The area under the ROC curve of grip strength was 0.863 and 0.900 for males and females respectively, and the cut-off point of it was determined to be 22.050 kg for men and 18.050 kg for women.

Conclusion

SSD and POD are common among older people. Decreased grip strength, advanced age, lower cognitive function, and fall history were independent risk factors for SSD, and grip strength was a significant predictor for SSD in aged patients after the arthroplasty.

Immune, Blood Cell, and Blood Gas Biomarkers of Delirium in Elderly Individuals with Hip Fracture Surgery

BACKGROUND

Postoperative delirium in elderly people with hip fracture is associated with various adverse clinical outcomes. Nevertheless, the pathophysiological processes underpinning delirium have remained elusive.

OBJECTIVES

The aim of this study was to explore the associations between delirium and its features and immune-inflammatory and blood gas biomarkers.

METHODS

In this prospective study, we examined 65 patients who underwent a hip fracture surgery and assessed the Confusion Assessment Method for the Intensive Care Unit, Richmond Agitation-Sedation Scale (RASS), and Delirium Rating Scale Revised-98 (DRS-R-98) before and during 4 days after the surgery. Complete blood count and venous blood gas markers were obtained at the same time points.

RESULTS

Delirium was observed in 19 patients and was accompanied by significantly increased pO2, number of white blood cells, neutrophil percentage, and neutrophil/lymphocyte ratio, and lower mean platelet volume (MPV) after adjusting for age, central nervous system (CNS) disease, blood loss during surgery, sleep disorders, and body mass index. The severity of delirium was associated with lowered number of platelets and MPV. Psychomotor disorders were associated with lower bicarbonate levels. The requirement of physical restraint of the patients was predicted by increased percentages of neutrophils and lymphocytes. Prior CNS disease was together with these biomarkers a significant predictor of delirium and severity of delirium.

CONCLUSION

Delirium and psychomotor disorders following hip fracture and surgery may be caused by immune-inflammatory and oxidative stress pathways probably attributable to an aseptic inflammatory process.

Risk factors for postoperative delirium and subsyndromal delirium in older patients in the surgical ward: A prospective observational study

Postoperative delirium (POD) and subsyndromal delirium (SSD) among older patients is a common, serious condition associated with a high incidence of negative outcomes. However, there are few accurate methods for the early detection of POD and SSD in surgical wards. This study aimed to identify risk factors of POD and SSD in older patients who were scheduled for surgery in a surgical ward. This was a prospective observational study. Study participants were older than 65 years, underwent urology surgery, and were hospitalized in the surgical ward between April and September 2019. Delirium symptoms were assessed using the Confusion Assessment Method (CAM) on the preoperative day, the day of surgery, and postoperative days 1–3 by the surgical ward nurses. SSD was defined as the presence of one or more CAM criteria and the absence of a diagnosis of delirium based on the CAM algorithm. Personal characteristics, clinical data, cognitive function, physical functions, laboratory test results, medication use, type of surgery and anesthesia, and use of physical restraint and bed sensor were collected from medical records. Multiple logistic regression analyses were conducted to identify the risk factors for both POD and SSD. A total of 101 participants (mean age 74.9 years) were enrolled; 19 (18.8%) developed POD (n = 4) and SSD (n = 15). The use of bed sensors (odds ratio 10.2, p = .001) was identified as a risk factor for both POD and SSD. Our findings suggest that the use of bed sensors might be related to the development of both POD and SSD among older patients in surgical wards.

Risk Factors for Delirium in the Palliative Care Population: A Systematic Review and Meta-Analysis

Objective: Delirium is common and highly distressing for the palliative care population. Until now, no study has systematically reviewed the risk factors of delirium in the palliative care population. Therefore, we performed a systematic review and meta-analysis to evaluate delirium risk factors among individuals receiving palliative care. Methods: We systematically searched PubMed, Medline, Embase, and Cochrane database to identify relevant observational studies from database inception to June 2021. The methodological quality of the eligible studies was assessed by the Newcastle Ottawa Scale. We estimated the pooled adjusted odds ratio (aOR) for individual risk factors using the inverse variance method. Results: Nine studies were included in the review (five prospective cohort studies, three retrospective case-control studies and one retrospective cross-section study). In pooled analyses, older age (aOR: 1.02, 95% CI: 1.01-1.04, I ² = 37%), male sex (aOR:1.80, 95% CI: 1.37-2.36, I ² = 7%), hypoxia (aOR: 0.87, 95% CI: 0.77-0.99, I ² = 0%), dehydration (aOR: 3.22, 95%CI: 1.75-5.94, I ² = 18%), cachexia (aOR:3.40, 95% CI: 1.69-6.85, I ² = 0%), opioid use (aOR: 2.49, 95%CI: 1.39-4.44, I ² = 0%), anticholinergic burden (aOR: 1.18, 95% CI: 1.07-1.30, I ² = 9%) and Eastern Cooperative Oncology Group Performance Status (aOR: 2.54, 95% CI: 1.56-4.14, I ² = 21%) were statistically significantly associated with delirium. Conclusion: The risk factors identified in our review can help to highlight the palliative care population at high risk of delirium. Appropriate strategies should be implemented to prevent delirium and improve the quality of palliative care services.

Preoperative Nutritional Status and Risk for Subsyndromal Delirium in Older Adults Following Joint Replacement Surgery

BACKGROUND

Subsyndromal delirium following surgery in older adults is related to increased lengths of hospital stay and increased admissions to long-term care. Impaired nutrition increases risk for delirium, but its relationship to subsyndromal delirium remains unclear.

PURPOSE

This correlational study examined the relationship between nutritional status and subsyndromal delirium in older adults.

METHODS

Assessments for subsyndromal delirium in 53 adults 65 years or older were completed for three consecutive days following joint replacement surgery. Relationships between nutritional status and subsyndromal delirium were analyzed. Level of significance for all tests was set at p ≤ .05.

RESULTS

Participants' scores from the Mini Nutritional Assessment screen were significantly related (p = .05) to subsyndromal delirium severity after accounting for variability posed by age and cognition status.

CONCLUSION

When preoperative risk assessment of older adults indicates nutritional risk, preoperative optimization may improve effectiveness of delirium prevention efforts.

Pain and delirium: mechanisms, assessment, and management

PURPOSE

Pain and delirium are common problems for older people. Both conditions are prevalent in acute hospital settings. In people living in the community, delirium often precipitates presentation to the emergency department. Pain and delirium are known to interact in a complex and multidirectional way. This can make it challenging for staff to recognize and treat pain in people with delirium.

METHODS

This paper aims to explore the complex relationship between pain and delirium and on pain assessment in delirium, drawing together evidence from a range of settings including acute medical, cardiac and orthopaedic post-operative cohorts, as well as from aged care.

RESULTS

A limited number of studies suggest there is an association between pain and delirium; however, this is a complex, particularly where analgesics which may-themselves cause delirium are prescribed. Factors acting on the pathway between pain and delirium may include depression, sleep deprivation and disturbance of the cholinergic system. Delirium affects the ability to self-report pain. The fluctuating nature of delirium as well as reduced awareness and attention may challenge practitioners in recognizing, assessing and treating pain. Evidence concerning the reliability and validity of current observational and self-assessment tools in people with delirium is unclear but some show promise in this population.

CONCLUSION

The current evidence base regarding assessing pain in people with delirium is lacking. Tentative recommendations, drawing on current guidelines require robust testing. Guidelines for people with pain and dementia require adaptations regarding the unique characteristics of delirium. The complex interplay between dementia, pain and delirium warrants further investigation across a range of settings.