Statin and Its Association With Delirium in the Medical ICU

Association between statin use on delirium and 30-day mortality in patients with chronic obstructive pulmonary disease in the intensive care unit

BACKGROUND

Delirium occurs frequently in patients with chronic obstructive pulmonary disease in the intensive care unit. Effective prevention and treatment strategies for delirium remain limited. We aimed to assess delirium and 30-day mortality in patients with chronic obstructive pulmonary disease who were statin and non-statin users.

METHODS

In this retrospective study, patients with chronic obstructive pulmonary disease were identified from the Medical Information Mart for Intensive Care database (MIMIC-IV). The primary exposure variable was the use of statins 3 days after entering the intensive care unit and the primary outcome measure was the presence of delirium. The secondary outcome measure was 30-day mortality. Since the cohort study was retrospective, we used an inverse probability weighting derived from the propensity score matching to balance different variables.

RESULTS

Among a cohort of 2725 patients, 1484 (54.5%) were statin users. Before propensity score matching, the prevalence of delirium was 16% and the 30-day mortality was 18% in patients with chronic obstructive pulmonary disease. Statin use was significantly negatively correlated with delirium, with an odds ratio of 0.69 (95% CI 0.56-0.85, p < 0.001) in the inverse probability weighted cohort and 30-day mortality of 0.7 (95% CI 0.57-0.85, p < 0.001).

CONCLUSIONS

Statin use is associated with a lower incidence of delirium and 30-day mortality in patients with chronic obstructive pulmonary disease in the intensive care unit.

Association between delirium and statin use in patients with congestive heart failure: a retrospective propensity score-weighted analysis

Background

The relationship between statin use and delirium remains controversial; therefore, we aimed to study the association between statin exposure and delirium and in-hospital mortality in patients with congestive heart failure.

Methods

In this retrospective study, patients with congestive heart failure were identified from the Medical Information Mart for Intensive Care database. The primary exposure variable was statin use 3 days after admission to the intensive care unit, and the primary outcome measure was the presence of delirium. The secondary outcome measure was in-hospital mortality. Since the cohort study was retrospective, we used inverse probability weighting derived from the propensity score to balance various variables.

Results

Of 8,396 patients, 5,446 (65%) were statin users. Before matching, the prevalence of delirium was 12.5% and that of in-hospital mortality was 11.8% in patients with congestive heart failure. Statin use was significantly negatively correlated with delirium, with an odds ratio of 0.76 (95% confidence interval: [0.66-0.87]; P < 0.001) in the inverse probability weighting cohort and in-hospital mortality of 0.66 (95% confidence interval: [0.58-0.75]; P < 0.001).

Conclusion

Statins administered in the intensive care unit can significantly reduce the incidence of delirium and in-hospital mortality in patients with congestive heart failure.

The Relationship between Delirium and Statin Use According to Disease Severity in Patients in the Intensive Care Unit

Objective

The aim of this study was to investigate the association between the use of statins and the occurrence of delirium in a large cohort of patients in the intensive care unit (ICU), considering disease severity and statin properties.

Methods

We obtained clinical and demographical information from 3,604 patients admitted to the ICU from January 2013 to April 2020. This included information on daily statin use and delirium state, as assessed by the Confusion Assessment Method for ICU. We used inverse probability of treatment weighting and categorized the patients into four groups based on the Acute Physiology and Chronic Health Evaluation II score (group 1: 0-10 - mild; group 2: 11-20 - mild to moderate; group 3: 21-30 - moderate to severe; group 4: > 30 - severe). We analyzed the association between the use of statin and the occurrence of delirium in each group, while taking into account the properties of statins.

Results

Comparisons between statin and non-statin patient groups revealed that only in group 2, patients who were administered statin showed significantly higher occurrence of delirium (p = 0.004, odds ratio [OR] = 1.58) compared to the patients who did not receive statin. Regardless of whether statins were lipophilic (p = 0.036, OR = 1.47) or hydrophilic (p = 0.032, OR = 1.84), the occurrence of delirium was higher only in patients from group 2.

Conclusion

The use of statins may be associated with the increases in the risk of delirium occurrence in patients with mild to moderate disease severity, irrespective of statin properties.

Statin Use and Delirium Risk: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Findings on the association of statin use with delirium risk are inconsistent.

THE STUDY QUESTION

Is statin use associated with delirium risk?

STUDY DESIGN

We searched PubMed, the Cochrane Library, and the EMBASE database, limiting the search to human patients and articles in English published until December 31, 2021. The effect size and 95% confidence interval (CI) were defined as the odds ratio (OR) and 95% CI, respectively, to indicate the difference in the incidence of delirium between statin use and nonuse groups. A random-effects model was selected in the case of high heterogeneity of study populations. We used funnel plots, Egger test, Duval and Tweedie trim-and-fill approach, and the classic fail-safe N to assess publication bias.

RESULTS

Of a total of 264 identified studies, 13 were selected for the qualitative review-4 RCTs and 9 observational cohort studies. Statin use was not associated with low delirium risk (pooled OR, 0·82; 95% CI, 0·64-1·04; P = 0·09). Substantial statistical heterogeneity was observed (I2, 90%). Visual inspection of the funnel plot of ORs from the studies revealed symmetry. Using the Grading of Recommendations Assessment, Development, and Evaluation approach, we assigned the evidence a rating of C and a weak recommendation for this review.

CONCLUSIONS

Statin use is not associated with delirium risk. More comprehensive RCTs are required to confirm the results.

Pharmacologic Management of Delirium in the Intensive Care Unit

Delirium, often underdiagnosed in the intensive care unit, is a common complication of critical illness that contributes to significant morbidity and mortality. Clinicians should be aware of common risk factors and triggers and should work to mitigate these as much as possible to reduce the occurrence of delirium. This review first provides an overview of the epidemiology, pathophysiology, evaluation, and consequences of delirium in critically ill patients. Presented next is the current evidence for the pharmacologic management of delirium, focusing on prevention and treatment of delirium in the intensive care unit. It concludes by outlining some emerging treatments of delirium.

Association between stress hyperglycemia ratio and delirium in older hospitalized patients: a cohort study

Background

It remains unclear whether stress hyperglycemia is associated with delirium. We performed this cohort study to determine the association between stress hyperglycemia and delirium.

Methods

We consecutively enrolled patients aged ≥70 years who were admitted to the Geriatric Department of West China Hospital between March 2016 and July 2017. Stress hyperglycemia ratio (SHR) was calculated as fasting blood glucose divided by estimated average glucose derived from glycosylated hemoglobin (HbA1c) and was classified into three tertiles. Delirium was screened within 24 h of admission and three times daily thereafter, using the confusion assessment method. The Cox proportional hazards models were used to assess the association of SHR with delirium.

Results

Among 487 included patients (mean age 83.0 years, 72.0% male), 50 (10.3%) patients experienced delirium during hospitalization. Compared to the second tertile, both the lowest and the highest SHR tertiles were independently associated with delirium (hazard ratio [HR] 3.71, 95% confidence interval [CI] 1.45-9.51; and HR 2.97, 95% CI 1.29-6.81, respectively). Similar results were found after further adjusting for statin comedication. Multiple-adjusted restricted cubic splines revealed a nonlinear relationship between SHR and delirium (P_nonlinearity=0.04). Adding SHR to conventional risk factors improved the risk prediction of delirium (net reclassification index 0.39, P=0.01; integrated discrimination improvement 0.07, P=0.03). Subgroup analyses indicated that the relationship between SHR and delirium was more apparent in patients with HbA1c <6.5%, with significantly higher HR in the first (3.65, 95% CI 1.11-11.97) and third (3.13, 95% CI 1.13-8.72) SHR tertiles compared to the second tertile, while there was no significant association between SHR and delirium in those with HbA1c ≥6.5%.

Conclusions

Both lower and higher SHR were associated with increased risk of delirium but only in patients with HbA1c <6.5%. Admission SHR may serve as a promising predictor of delirium, and incorporating this biomarker into prediction algorithms might have potential clinical utility in aiding delirium risk stratification, especially in those with HbA1c <6.5%.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02935-6.

Effects of Atorvastatin Therapy on Postoperative Delirium After Malignant Tumor Surgeries in Older Adults

INTRODUCTION

Postoperative delirium (POD) is one of the prevalent and potentially fatal clinical conditions, leading to high disability and mortality in older patients, as well as increased duration of hospital stay and more hospitalization expenses. There were no effective drugs in the clinical management of POD, and an absence of evidence-based medicine concerning the treatment of POD.

MATERIALS AND METHODS

The present study explored whether atorvastatin (Ato) can decrease the occurrence rate of POD. The present research included patients over the age of 60 who were hospitalized to critical care units (ICUs) following surgery for malignant tumors. Patients received Ato (40mg/day) or placebos utilizing a computer-based random sequencing (in a 1:1 ratio). The primary outcome measure was the occurrence of delirium within the first seven days following surgery.

RESULTS

A total of 230 individuals were classified into two groups, namely the placebo group (n=123) and the Ato group (n=107). Patients belonging to two groups had similar baseline clinical data, and there were no statistically significant differences between them. The occurrence of delirium in the Ato group was remarkably reduced unlike the case in the placebo group. 30-day all-cause mortality did not vary significantly between the two groups. Pulmonary infection and Bedsore were significantly decreased in the Ato group than the placebo group, there were no statistically significant differences between the two groups in rhabdomyolysis and abnormal liver enzymes. In terms of medication responses, there were no statistically significant differences between the two groups. Ato patients had remarkably shortened hospital stays and spent remarkably less on hospitalization expenditures in comparison with those in the placebo group.

CONCLUSION

The findings from the present research indicated that Ato can decrease the occurrence of delirium following surgical operation of malignant tumors among elderly patients, it also can reduce the duration of hospitalization, hospital cost, and post-surgical complications, but not improve 30-day all-cause mortality.

REGISTRATION NUMBER

ChiCTR-IPR-17011984.

Delirium in critical illness: clinical manifestations, outcomes, and management

Delirium is the most common manifestation of brain dysfunction in critically ill patients. In the intensive care unit (ICU), duration of delirium is independently predictive of excess death, length of stay, cost of care, and acquired dementia. There are numerous neurotransmitter/functional and/or injury-causing hypotheses rather than a unifying mechanism for delirium. Without using a validated delirium instrument, delirium can be misdiagnosed (under, but also overdiagnosed and trivialized), supporting the recommendation to use a monitoring instrument routinely. The best-validated ICU bedside instruments are CAM-ICU and ICDSC, both of which also detect subsyndromal delirium. Both tools have some inherent limitations in the neurologically injured patients, yet still provide valuable information about delirium once the sequelae of the primary injury settle into a new post-injury baseline. Now it is known that antipsychotics and other psychoactive medications do not reliably improve brain function in critically ill delirious patients. ICU teams should systematically screen for predisposing and precipitating factors. These include exacerbations of cardiac/respiratory failure or sepsis, metabolic disturbances (hypoglycemia, dysnatremia, uremia and ammonemia) receipt of psychoactive medications, and sensory deprivation through prolonged immobilization, uncorrected vision and hearing deficits, poor sleep hygiene, and isolation from loved ones so common during COVID-19 pandemic. The ABCDEF (A2F) bundle is a means to facilitate implementation of the 2018 Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU (PADIS) Guidelines. In over 25,000 patients across nearly 100 institutions, the A2F bundle has been shown in a dose-response fashion (i.e., greater bundle compliance) to yield improved survival, length of stay, coma and delirium duration, cost, and less ICU bounce-backs and discharge to nursing homes.

Effectiveness and harms of pharmacological interventions for the treatment of delirium in adults in intensive care units after cardiac surgery: a systematic review

OBJECTIVE

The objective of this review was to synthesize the best available evidence on the effectiveness and harms of pharmacological interventions for the treatment of delirium in adult patients in the intensive care unit (ICU) after cardiac surgery.

INTRODUCTION

Patients who undergo cardiac surgery are at high risk of delirium (incidence: 50-90%). Delirium has deleterious effects, increasing the risk of death and adversely affecting recovery. Clinical interventional trials have been conducted to prevent and treat postoperative delirium pharmacologically including antipsychotics and sedatives. These trials have provided some evidence about efficacy and influenced clinical decision making. However, much reporting is incomplete and provides biased assessments of efficacy; benefits are emphasized while harms are inadequately reported.

INCLUSION CRITERIA

Participants were ≥ 16 years, any sex or ethnicity, who were treated postoperatively in a cardiothoracic ICU following cardiac surgery and were identified as having delirium. Any pharmacological intervention for the treatment of delirium was included, regardless of drug classification, dosage, intensity or frequency of administration. Outcomes of interest of this review were: mortality, duration and severity of delirium, use of physical restraints, quality of life, family members' satisfaction with delirium management, duration/severity of the aggressive episode, associated falls, severity of accidental self-harm, pharmacological harms, harms related to over-sedation, ICU length of stay, hospital length of stay (post ICU), total hospital length of stay, need for additional intervention medication and need for rescue medication. Randomized controlled trials were considered first and in their absence, non-randomized controlled trials and quasi-experimental would have been considered, followed by analytical observational studies.

METHODS

A search was conducted in PubMed, Embase, CINAHL, Web of Science, Cochrane Central Register of Controlled Trials, Scopus, Epistemonikos, Australian New Zealand Clinical Trials Registry, ClinicalTrials.gov, Clinical Trials in New Zealand, and ProQuest Dissertations and Theses to locate both published and unpublished studies. There was no date limit for the search. A hand search for primary studies published between January 1, 2012 and November 17, 2018 in relevant journals was also conducted. Only studies published in English were considered for inclusion. Two reviewers independently assessed the methodological quality using standardized critical appraisal instruments from JBI and McMaster University. Quantitative data were extracted using the standardized JBI data extraction tool. A meta-analysis was not performed, as there was too much clinical and methodological heterogeneity in the included studies. Results have been presented in a narrative form. Standard GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) evidence assessment of outcomes has been reported.

RESULTS

Three RCTs investigating morphine versus haloperidol (n = 53), ondansetron versus haloperidol (n = 72), and dexmedetomidine versus midazolam (n = 80) were included. Due to heterogeneity and incomplete reporting, a meta-analysis was not feasible. Overall, the methodological quality of these studies was found to be low. Additionally, this review found reporting of harms to be inadequate and superficial for all three studies and did not meet the required standards for harms reporting, as defined by the CONSORT statement extension for harms.

CONCLUSIONS

It was not possible to draw any valid conclusions regarding the effectiveness of morphine vs haloperidol, ondansetron vs haloperidol or dexmedetomidine vs midazolam in treating delirium after cardiac surgery. This is due to the low number of studies, the poor methodological quality in conducting and reporting and the heterogeneity between the studies.

Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU

OBJECTIVE

To update and expand the 2013 Clinical Practice Guidelines for the Management of Pain, Agitation, and Delirium in Adult Patients in the ICU.

DESIGN

Thirty-two international experts, four methodologists, and four critical illness survivors met virtually at least monthly. All section groups gathered face-to-face at annual Society of Critical Care Medicine congresses; virtual connections included those unable to attend. A formal conflict of interest policy was developed a priori and enforced throughout the process. Teleconferences and electronic discussions among subgroups and whole panel were part of the guidelines' development. A general content review was completed face-to-face by all panel members in January 2017.

METHODS

Content experts, methodologists, and ICU survivors were represented in each of the five sections of the guidelines: Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption). Each section created Population, Intervention, Comparison, and Outcome, and nonactionable, descriptive questions based on perceived clinical relevance. The guideline group then voted their ranking, and patients prioritized their importance. For each Population, Intervention, Comparison, and Outcome question, sections searched the best available evidence, determined its quality, and formulated recommendations as "strong," "conditional," or "good" practice statements based on Grading of Recommendations Assessment, Development and Evaluation principles. In addition, evidence gaps and clinical caveats were explicitly identified.

RESULTS

The Pain, Agitation/Sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) panel issued 37 recommendations (three strong and 34 conditional), two good practice statements, and 32 ungraded, nonactionable statements. Three questions from the patient-centered prioritized question list remained without recommendation.

CONCLUSIONS

We found substantial agreement among a large, interdisciplinary cohort of international experts regarding evidence supporting recommendations, and the remaining literature gaps in the assessment, prevention, and treatment of Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) in critically ill adults. Highlighting this evidence and the research needs will improve Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) management and provide the foundation for improved outcomes and science in this vulnerable population.

The Role of Perioperative Statin Use in the Prevention of Delirium After Total Knee Replacement Under Spinal Anesthesia

BACKGROUND

The relationship between statin use and incidence of postoperative delirium (POD) is controversial. We investigated the association between perioperative statin use and occurrence of delirium after total knee arthroplasty (TKA) under spinal anesthesia.

METHODS

We retrospectively reviewed the electronic medical records of patients who underwent TKA under spinal anesthesia at a single tertiary care hospital between January 2005 and October 2017. POD incidence was recorded for patients who received statins continuously from 1 month before surgery until discharge and for patients who did not receive any statins. Univariable and multivariable logistic regression analyses were conducted to investigate an association between occurrence of POD and perioperative statin use.

RESULTS

In total, 6020 procedures were included, and 992 (16.4%) were associated with perioperative statin use. POD was confirmed for 304 (5.0%) procedures. The statin group showed a 1.7% significant lower incidence (P = .017) of POD (35/992, 3.5%) than the no statin group (1420/5,028, 5.4%). In multivariable logistic regression analysis, the POD incidence in the statin group was 34% lower than that in the no statin group (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.45-0.97, P = .036]. Moreover, the POD incidence was decreased by 37% (OR 0.63, 95% CI 0.40-0.99, P = .047) and 79% (OR 0.21, 95% CI 0.05-0.88, P = .033) respectively, when atorvastatin and simvastatin were administered.

CONCLUSION

Continuous perioperative statin use may be associated with a significantly lower risk of delirium after TKA under spinal anesthesia; simvastatin was the most effective statin for POD prevention.

Preoperative statins are associated with a reduced risk of postoperative delirium following vascular surgery

Delirium is a common complication of vascular surgery. The protective effect of preoperative statins on delirium after vascular surgery is controversial. The authors hypothesized that preoperative statin administration would decrease the incidence of delirium after vascular surgery. From May 2010 to May 2015, 1,132 patients underwent vascular surgery. Postoperative delirium was diagnosed from patients’ medical records. The incidence of delirium was 11.5%. The preoperative statin exposure was not associated with reduced delirium in the univariate analysis. After adjusting for covariates, preoperative statin exposure was associated with reduced delirium (OR, 0.54; 95% CI, 0.33–0.87; p = 0.011). This favor effect of statin for delirium was observed after propensity matching (OR, 0.59; 95% CI, 0.34–1.02; p = 0.060). However, the median hospital lengths of stay and in-hospital mortality were not statistically different between the two groups. CRP(C-reactive protein) levels in the unmatched population were lower in the preoperative statin group compared with the other group (p<0.001), however, there was only numerically different without statistical difference after matching (p = 0.083). Preoperative statin use was associated with a decreased incidence of postoperative delirium in patients who underwent vascular surgery. However, preoperative statin did not reduce mortality rate and hospital stay.