Delirium after lung transplantation: Association with recipient characteristics, hospital resource utilization, and mortality

Association of Postoperative Delirium With Incident Dementia and Graft Outcomes Among Kidney Transplant Recipients

BACKGROUND

Kidney transplant (KT) recipients have numerous risk factors for delirium, including those shared with the general surgical population (eg, age and major surgery) and transplant-specific factors (eg, neurotoxic immunosuppression medications). Evidence has linked delirium to long-term dementia risk in older adults undergoing major surgery. We sought to characterize dementia risk associated with post-KT delirium.

METHODS

Using the United States Renal Data System datasets, we identified 35 800 adult first-time KT recipients ≥55 y. We evaluated risk factors for delirium using logistic regression. We evaluated the association between delirium and incident dementia (overall and by subtype: Alzheimer's, vascular, and other/mixed-type), graft loss, and death using Fine and Gray's subhazards models and Cox regression.

RESULTS

During the KT hospitalization, 0.9% of recipients were diagnosed with delirium. Delirium risk factors included age (OR = 1.40, 95% CI, 1.28-1.52) and diabetes (OR = 1.38, 95% CI, 1.10-1.73). Delirium was associated with higher risk of death-censored graft loss (aHR = 1.52, 95% CI, 1.12-2.05) and all-cause mortality (aHR = 1.53, 95% CI, 1.25-1.89) at 5 y post-KT. Delirium was also associated with higher risk of dementia (adjusted subhazard ratio [aSHR] = 4.59, 95% CI, 3.48-6.06), particularly vascular dementia (aSHR = 2.51, 95% CI, 1.01-6.25) and other/mixed-type dementia (aSHR = 5.58, 95% CI, 4.24-7.62) subtypes. The risk of all-type dementia associated with delirium was higher for younger recipients aged between 55 and 64 y ( Pinteraction  = 0.01).

CONCLUSIONS

Delirium is a strong risk factor for subsequent diagnosis of dementia among KT recipients, particularly those aged between 55 and 64 y at the time of transplant. Patients experiencing posttransplant delirium might benefit from early interventions to enhance cognitive health and surveillance for cognitive impairment to enable early referral for dementia care.

Disturbed sleep after lung transplantation is associated with worse patient-reported outcomes and chronic lung allograft dysfunction

Many lung transplant recipients fail to derive the expected improvements in functioning, HRQL, or long-term survival. Sleep may represent an important, albeit rarely examined, factor influencing lung transplant outcomes. Within a larger cohort study, 141 lung transplant recipients completed the Medical Outcomes Study (MOS) Sleep Scale along with a broader survey of patient-reported outcome (PRO) measures and frailty assessment. MOS Sleep yields the Sleep Problems Index (SPI); we also derived an insomnia-specific subscale. Potential perioperative predictors of disturbed sleep and time to chronic lung allograft dysfunction (CLAD) and death were derived from medical records. We investigated associations between perioperative predictors on SPI and Insomnia and associations between SPI and Insomnia on PROs and frailty by linear regressions, adjusting for age, sex, and lung function. We evaluated the associations between SPI and Insomnia on time to CLAD and death using Cox models, adjusting for age, sex, and transplant indication. Post-transplant hospital length of stay >30 days was associated with worse sleep by SPI and insomnia (SPI: p=0.01; Insomnia p=0.02). Worse sleep by SPI and insomnia was associated with worse depression, cognitive function, HRQL, physical disability, health utilities, and Fried Frailty Phenotype frailty (all p<0.01). Those in the worst quartile of SPI and insomnia exhibited increased risk of CLAD (HR 2.18; 95%CI: 1.22-3.89 ; p=0.01 for SPI and HR 1.96; 95%CI 1.09-3.53; p=0.03 for insomnia). Worsening in SPI but not insomnia was also associated with mortality (HR: 1.29; 95%CI: 1.05-1.58; p=0.01). Poor sleep after lung transplant may be a novel predictor of patient reported outcomes, frailty, CLAD, and death with potentially important screening and treatment implications.

Associations between delirium and SARS-CoV-2 pandemic visitor restrictions among hospitalized patients

OBJECTIVES

Delirium is associated with increased morbidity and mortality, but environmental and behavioral factors may decrease the risk of developing delirium and thus must be considered. To investigate trends in delirium prevalence and examine associations of visitor restrictions with delirium diagnoses among all patients hospitalized during and prior to the novel coronavirus SARS-CoV-2 (COVID-19) pandemic.

STUDY DESIGN

Retrospective epidemiological assessment.

METHODS

The medical records of all patients (n = 33,141) hospitalized within a three-hospital academic medical center system in a large Midwestern metropolitan area from March 20, 2019, through March 19, 2021, were analyzed.

RESULTS

The overall prevalence of delirium during COVID-19 was 11.26% (confidence interval [CI]: 10.79%, 11.73%) compared to 9.28% (CI: 8.82%, 9.73%) before COVID-19. From our adjusted logistic regression analyses, we observed that the odds of delirium among non-isolated patients were significantly higher during COVID-19 visitor restrictions (adjusted odds ratio [aOR]: 1.354; 95% CI: 1.233, 1.488; P < 0.0001) than before. The odds of delirium among isolated patients were not significantly higher during COVID-19 visitor restrictions (aOR: 1.145; 95% CI: 0.974, 1.346; P = 0.1006) than before.

CONCLUSIONS

Medically isolated patients remained at high risk of developing delirium both prior to and during COVID-19 era visitor restrictions. However, non-medically isolated patients had a significantly increased risk of delirium during the social isolation of visitor restrictions compared to prior to visitor restrictions.

Low Skeletal Muscle Mass and the Incidence of Delirium in Hospitalized Older Patients: A Systematic Review and Meta-Analysis of Observational Studies

Background

Both low skeletal muscle mass and delirium are prevalent in older hospitalized patients, while their associations are unclear. This systematic review and meta-analysis aim to investigate the associations between low skeletal muscle mass and the incidence of delirium in hospitalized patients.

Methods

The PubMed, Web of Science, and Embase were searched for relevant studies published before May 2022, and we conducted this systematic review and meta-analysis according to the PRISMA and MOOSE guidelines. The summary odds ratios (OR) and 95% confidence intervals (CI) were estimated, and subgroup analyses were also conducted according to the age and major surgeries.

Results

Finally, nine studies with 3 828 patients were included. The pooled result showed no significant association between low skeletal muscle mass and the incidence of delirium (OR 1.69, 95% CI 0.85 to 2.52). However, sensitivity analysis suggested that one study caused a significant alteration of the summary result, and the meta-analysis of the remaining 8 studies showed that low skeletal muscle mass was significantly associated with an 88% increased incidence of delirium (OR 1.88, 95% CI 1.43 to 2.33). Furthermore, subgroup analyses indicated that low skeletal muscle mass was associated with a higher incidence of delirium in patients ≥75 years old or undergoing major surgeries instead of those <75 years old or without surgeries, respectively.

Conclusions

Hospitalized patients with low skeletal muscle mass might have higher incidence of delirium, particularly in those of older age and undergoing major surgeries. Therefore, great attention should be paid to these patients.

The Intersection of Aging and Lung Transplantation: its Impact on Transplant Evaluation, Outcomes, and Clinical Care

Purpose

Older adults (age ≥ 65 years) are the fastest growing age group undergoing lung transplantation. Further, international consensus document for the selection of lung transplant candidates no longer suggest a fixed upper age limit. Although carefully selected older adults can derive great benefit, understanding which older adults will do well after transplant with improved survival and health-related qualiy of life is key to informed decision-making. Herein, we review the epidemiology of aging in lung transplantation and its impact on outcomes, highlight selected physiological measures that may be informative when evaluating and managing older lung transplant patients, and identify directions for future research.

Recent Findings

In general, listing and transplanting older, sicker patients has contributed to worse clinical outcomes and greater healthcare use. Emerging evidence suggest that measures of physiological age, such as frailty, body composition, and neurocognitive and psychosocial function, may better identify risk for poor transplant outcomes than chronlogical age.

Summary

The evidence base to inform transplant decision-making and improvements in care for older adults is small but growing. Multipronged efforts at the intersection of aging and lung transplantation are needed to improve the clinical and patient centered outcomes for this large and growing cohort of patients. Future research should focus on identifying novel and ideally modifiable risk factors for poor outcomes specific to older adults, better approaches to measuring physiological aging (e.g., frailty, body composition, neurocognitive and psychosocial function), and the underlying mechanisms of physiological aging. Finally, interventions that can improve clinical and patient centered outcomes for older adults are needed.

Delirium Development After Lung Transplantation: An Intraoperative Assessment

BACKGROUND

This study aimed to evaluate the relationship between intraoperative hemodynamic and laboratory parameters with postoperative delirium development after lung transplantation.

METHODS

A total of 77 patients who underwent lung transplantation in a single center were included in the study. Demographic and clinical data recorded at critical intraoperative stages (after induction [T1], after bilateral lungs are dissected [T2], while the patient is ventilated for 1 lung [T3], while the unilateral transplanted lung is ventilated [T4], while bilateral transplanted lungs are ventilated [T5], and after the thorax is closed [T6]), postoperative complications, mechanical ventilation duration, intensive care, and hospitalization durations and mortality rates were recorded.

RESULTS

A total of 83.1% of the 77 patients were male, and the mean (SD) age was 47.56 (12.95) years. The mean body mass index (calculated as weight in kilograms divided by height in meters squared) was 23.30 (3.99), and the median Charles Comorbidity Index (CCI) was 1. The diagnosis of 36.4% of the patients was chronic obstructive pulmonary disease. Delirium was seen in 51.9% of the patients. Age, CCI, intraoperative mean arterial pressure changes, lactate levels, mechanical ventilation duration, and hospital stay were all associated with delirium development.

CONCLUSION

Age, CCI, duration of mechanical ventilation, and hospital stay were independent predictors of postoperative delirium development. We believe that our study will be a guide for future prospective randomized controlled studies.

Postoperative management of children after lung transplantation

Pediatric lung transplantation is a highly specialized treatment option at a select few hospitals caring for children. Advancements in surgical and medical approaches in the care of these children have improved their care with only minimal improvement in outcomes which remain the lowest of all solid organ transplants. A crucial time period in the management of these children is in the perioperative period after performance of the lung transplant. Supporting allograft function, preventing infection, maintaining fluid balance, achieving pain control, and providing optimal respiratory support are all key factors required for this highly complex pediatric patient population. We review commonly encountered complications that these patients often experience and provide strategies for management.

Delirium Among Adults Undergoing Solid Organ Transplantation

Purpose of Review

To summarize the research on post-operative delirium among patients undergoing solid organ transplantation in efforts to improve recognition, evaluation, and management, as well as highlight areas for future research.

Recent Findings

Delirium is a common complication in patients with organ failure before and after undergoing solid organ transplant (range: 4.7-47%). However, it is frequently unrecognized and underdiagnosed-even among those closely monitored after major surgery-given that its manifestation is often variable and inconsistent. Delirium has multifactorial etiologies comprising of a complex mix of predisposing recipient, donor, and transplant factors, as well as intraoperative and perioperative factors. Evidence suggests that delirium risk increases with presence of a greater number of such risk factors, and can lead to adverse outcomes such as increased hospital length of stay, time in the ICU, time on mechanical ventilators, graft dysfunction, graft loss, and mortality. Though no trials have been conducted among transplant populations specifically, delirium has been shown to be preventable among hospitalized older adults generally. Multicomponent, primary prevention strategies designed to target multiple risk factors of delirium, such as cognitive impairment, sleep deprivation, immobility, visual impairment, hearing impairment, and dehydration, have been identified as most effective. Whether these approaches translate to improvements in quality of life and long-term health outcomes among patients with organ failure before and after transplantation is yet to be determined.

Summary

Delirium is an important, common, yet potentially preventable complication among patients with organ failure. Future studies are needed to test the efficacy of multicomponent, primary prevention strategies on long-term health outcomes among these vulnerable populations.

Postoperative Management of Lung Transplant Recipients in the Intensive Care Unit

The number of lung transplantations is progressively increasing worldwide, providing new challenges to interprofessional teams and the intensive care units. The outcome of lung transplantation recipients is critically affected by a complex interplay of particular pathophysiologic conditions and risk factors, knowledge of which is fundamental to appropriately manage these patients during the early postoperative course. As high-grade evidence-based guidelines are not available, the authors aimed to provide an updated review of the postoperative management of lung transplantation recipients in the intensive care unit, which addresses six main areas: (1) management of mechanical ventilation, (2) fluid and hemodynamic management, (3) immunosuppressive therapies, (4) prevention and management of neurologic complications, (5) antimicrobial therapy, and (6) management of nutritional support and abdominal complications. The integrated care provided by a dedicated multidisciplinary team is key to optimize the complex postoperative management of lung transplantation recipients in the intensive care unit.

Consensus document for the selection of lung transplant candidates: An update from the International Society for Heart and Lung Transplantation

Tens of thousands of patients with advanced lung diseases may be eligible to be considered as potential candidates for lung transplant around the world each year. The timing of referral, evaluation, determination of candidacy, and listing of candidates continues to pose challenges and even ethical dilemmas. To address these challenges, the International Society for Heart and Lung Transplantation appointed an international group of members to review the literature, to consider recent advances in the management of advanced lung diseases, and to update prior consensus documents on the selection of lung transplant candidates. The purpose of this updated consensus document is to assist providers throughout the world who are caring for patients with pulmonary disease to identify potential candidates for lung transplant, to optimize the timing of the referral of these patients to lung transplant centers, and to provide transplant centers with a framework for evaluating and selecting candidates. In addition to addressing general considerations and providing disease specific recommendations for referral and listing, this updated consensus document includes an ethical framework, a recognition of the variability in acceptance of risk between transplant centers, and establishes a system to account for how a combination of risk factors may be taken into consideration in candidate selection for lung transplantation.

The association of post-operative delirium with patient-reported outcomes and mortality after lung transplantation

Post-operative delirium after lung transplantation is common. Its associations with health-related quality of life (HRQL), depression, and mortality remains unknown. In 236 lung transplant recipients, HRQL and depressive symptoms were assessed as part of a structured survey battery before and after transplantation. Surveys included the Geriatric Depressive Scale (GDS) and Short Form 12 (SF12). Delirium was assessed throughout the post-operative intensive care unit (ICU) stay with Confusion Assessment Method for ICU. Delirium and mortality data were extracted from electronic medical records. We examined associations between delirium and changes in depressive symptoms and HRQL using linear mixed effects models and association between delirium and mortality with Cox-proportional hazard models. Post-operative delirium occurred in 34 participants (14%). Delirium was associated with attenuated improvements in SF12-PCS (difference ₋4.0; 95%CI: -7.4, -0.7) but not SF12-MCS (difference 2.2; 95%CI: -0.7,5.7) or GDS (difference ₋0.4; 95%CI: -1.5,0.7). Thirty-two participants died during the study period. Delirium was associated with increased adjusted hazard risk of mortality (HR 17.9, 95%CI: 4.4,72.5). Delirium after lung transplantation identifies a group at increased risk for poorer HRQL and death within the first post-operative year. Further studies should investigate potential causal links between delirium, and poorer HRQL and mortality risk after lung transplantation.

Lung transplantation: candidate selection and timing of transplant

PURPOSE OF REVIEW

Over the past two decades, lung transplant has become the mainstay of treatment for several end-stage lung diseases. As the field continues to evolve, the criteria for referral and listing have also changed. The last update to these guidelines was in 2014 and several studies since then have changed how patients are transplanted. Our article aims to briefly discuss these updates in lung transplantation.

RECENT FINDINGS

This article discusses the importance of early referral of patients for lung transplantation and the concept of the 'transplant window'. We review the referral and listing criteria for some common pulmonary diseases and also cite the updated literature surrounding the absolute and relative contraindications keeping in mind that they are a constantly moving target. Frailty and psychosocial barriers are difficult to assess with the current assessment tools but continue to impact posttransplant outcomes. Finally, we discuss the limited data on transplantation in acute respiratory distress syndrome (ARDS) due to COVID19 as well as extracorporeal membrane oxygenation bridge to transplantation.

SUMMARY

The findings discussed in this article will strongly impact, if not already, how we select candidates for lung transplantation. It also addresses some aspects of lung transplant such as frailty and ARDS, which need better assessment tools and clinical data.

Extracorporeal membrane oxygenation as a bridge vs. non-bridging for lung transplantation: A systematic review and meta-analysis

Whether extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation (BTT) can achieve a similar survival to non-BTT remains controversial. We conducted this meta-analysis to compare the outcomes between ECMO BTT and non-BTT to facilitate better clinical decision-making. Seven databases were searched for eligible studies comparing ECMO BTT and non-BTT. The primary endpoints included survival, intraoperative indicators, postoperative hospitalization indicators, and postoperative complications. Nineteen studies (involving 7061 participants) were included in the final analysis. The outcomes of overall survival, overall survival rate, graft survival rate, in-hospital mortality, postoperative hospital days, postoperative intensive care unit days, postoperative ventilation time, blood transfusion volume, and postoperative complications were all better in the non-BTT group. The total mortality in ECMO bridging was 23.03%, in which the top five causes of death were right heart failure (8.03%), multiple organ failure (7.03%), bleeding (not cranial) (4.67%), cranial bleeding (3.15%), and sepsis (2.90%). In summary, Non-BTT is associated with better survival and fewer complications compared to BTT. When ECMO may be the only option, the patient and medical team need to realize the increased risk of ECMO by complications and survival.

Clinical and Neuroimaging Correlates of Post-Transplant Delirium

Delirium is common among adults undergoing hematopoietic stem cell transplantation (HCT), although the clinical and neuroimaging correlates of post-HCT delirium have not been adequately delineated. We therefore examined the frequency of delirium and neuroimaging correlates of post-transplant delirium in a retrospective cohort of 115 adults undergoing neuroimaging after allogeneic HCT. Delirium was established using previously validated methods for retrospective identification of chart-assessed postprocedural delirium. Chart reviews were independently conducted by a multidisciplinary team with expertise in HCT, psychiatry, and psychology on consecutive allogeneic HCT patients who underwent neuroimaging assessments and transplantation at a single center between January 2009 and December 2016. Neuroimaging markers of white matter damage and brain volume loss were also recorded. In total, 115 patients were included, ranging in age from 20 to 74 years (mean [SD] age, 49 [13]). Fifty-three patients (46%) developed post-HCT delirium. In an adjusted model, delirium incidence was associated with older age (odds ratio [OR], 1.92 [1.28, 2.87] per decade, P = .002), greater severity of white matter hyperintensities (OR, 1.95 [1.06, 3.57], P = .031), and conditioning intensity (OR, 6.37 [2.20, 18.45], P < .001) but was unrelated to cortical atrophy (P = .777). Delirium was associated with fewer hospital-free days (P = .023) but was not associated with overall survival (hazard ratio, 0.95 [0.56, 1.61], P = .844). Greater incidence of delirium following HCT was associated with greater age, microvascular burden, and conditioning intensity. Pre-HCT consideration of microvascular burden and other neuroimaging biomarkers of risk may be warranted.

Diary for self-observation: A self-management tool for recipients of lung transplantation-A pilot study

Aim

To (a) explore how the diary contributes to patient motivation for monitoring self‐management and (b) explore the nurses' experience of how the diary supports the patients' self‐management after lung transplantation.

Design

A quantitative and qualitative study design.

Methods

Fifteen patients and four nurses participated. Data were analysed descriptively and thematically.

Results

This pilot study shows that the diary strengthens patients' self‐management in the first postoperative period. Nurses were confident that the patients were structured about self‐observation when using the diary.

Incidence, Risk Factors, and Sequelae of Post-kidney Transplant Delirium

Background Frail kidney transplant (KT) recipients may be particularly vulnerable to surgical stressors, resulting in delirium and subsequent adverse outcomes. We sought to identify the incidence, risk factors, and sequelae of post-KT delirium.Methods We studied 125,304 adult KT recipients (1999-2014) to estimate delirium incidence in national registry claims. Additionally, we used a validated chart abstraction algorithm to identify post-KT delirium in 893 adult recipients (2009-2017) from a cohort study of frailty. Delirium sequelae were identified using adjusted logistic regression (length of stay ≥2 weeks and institutional discharge [skilled nursing or rehabilitation facility]) and adjusted Cox regression (death-censored graft loss and mortality).Results Only 0.8% of KT recipients had a delirium claim. In the cohort study, delirium incidence increased with age (18-49 years old: 2.0%; 50-64 years old: 4.6%; 65-75 years old: 9.2%; and ≥75 years old: 13.8%) and frailty (9.0% versus 3.9%); 20.0% of frail recipients aged ≥75 years old experienced delirium. Frailty was independently associated with delirium (odds ratio [OR], 2.05; 95% confidence interval [95% CI], 1.02 to 4.13; P=0.04), but premorbid global cognitive function was not. Recipients with delirium had increased risks of ≥2-week length of stay (OR, 5.42; 95% CI, 2.76 to 10.66; P<0.001), institutional discharge (OR, 22.41; 95% CI, 7.85 to 63.98; P<0.001), graft loss (hazard ratio [HR], 2.73; 95% CI, 1.14 to 6.53; P=0.03), and mortality (HR, 3.12; 95% CI, 1.76 to 5.54; P<0.001).Conclusions Post-KT delirium is a strong risk factor for subsequent adverse outcomes, yet it is a clinical entity that is often missed.

Neurological Sequelae and Clinical Outcomes After Lung Transplantation

Background

Neurological complications are common after lung transplantation. However, no large cohort studies have examined the incidence, predictors, and clinical significance of neurological events sustained by lung transplant recipients.

Methods

We conducted a retrospective cohort analysis of a consecutive series of lung transplant recipients, transplanted at Duke University Medical Center between May 2014 and February 2017 (n = 276). Early neurological complications (ie, occurring during the first week after transplant) were documented by transplant mental health specialists and included delirium, ischemic injury, and posterior reversible encephalopathy syndrome. Analyses accounted for age, native disease, sex, type of transplant, lung allocation score, and primary graft dysfunction. The objectives of the study were to characterize the prevalence and predictors of early neurological sequelae (NSE), occurring during the first week posttransplant, and the association between NSE and subsequent clinical outcomes, including length of stay and mortality.

Results

Neurological sequelae were common, occurring in 123 (45%) patients. Fifty-seven patients died over a follow-up interval of 2.1 years. The most common NSE were postoperative delirium (n = 110 [40%]) and posterior reversible encephalopathy syndrome (n = 12 [4%]), followed by stroke/transient ischemic attack and neurotoxicity. Higher lung allocation score was the strongest predictor of delirium. The presence of a NSE was associated with longer length of hospital stay (32 days vs 17 days, P < 0.001) and greater mortality (hazard ratio, 1.90; 95% confidence interval, 1.09-3.32], P = 0.024), with the greatest mortality risk occurring approximately 2 years after transplantation.

Conclusions

Neurological events are relatively common after lung transplantation and associated with adverse clinical outcomes.