Challenges of Delirium Management in Patients with Traumatic Brain Injury: From Pathophysiology to Clinical Practice

Association Between Pupil Light Reflex and Delirium in Adults With Traumatic Brain Injury: Preliminary Findings

ABSTRACT

BACKGROUND: Delirium is a common neurological complication in patients admitted to the intensive care unit (ICU) after moderate to severe traumatic brain injury (TBI). Although current clinical guidelines prioritize delirium prevention, no specific tool is tailored to detect early signs of delirium in TBI patients. This preliminary 2-phase observational study investigated the correlation between the pupillary light reflex (PLR), measured with a pupillometer during mechanical ventilation, and the development of postextubation delirium in TBI patients. METHODS: A convenience sample of 26 adults with moderate to severe TBI under mechanical ventilation was recruited during their ICU stay. In phase I, PLR measurements were performed in the first 3 days of ICU admission using automated infrared pupillometry. In phase II, 2 raters independently extracted delirium data in the 72 hours post extubation period from medical records. Delirium was confirmed with a documented medical diagnosis. Point-biserial correlations (rpb) were used to examine the association between PLR scores and the presence of postextubation delirium. Student t tests were also performed to compare mean PLR scores between patients with and without delirium. RESULTS: Ten TBI patients (38%) were diagnosed with postextubation delirium, whereas 16 (62%) were not. Significant correlations between delirium and 2 PLR variables were found: pupil constriction percentage (rpb(24) = -0.526, P = .006) and constriction velocity (rpb(24) = -0.485, P = .012). The t test also revealed a significant difference in constriction percentage and velocity scores between TBI patients with and without delirium (P ≤ .01). CONCLUSION: Our findings suggest that the use of pupillometry in the first 3 days of mechanical ventilation during an ICU stay may help identify TBI patients at risk for delirium after extubation. Although further research is necessary to support its validity, this technological tool may enable ICU nurses to better screen TBI patients for delirium and prevent its development.

Transcutaneous Cervical Vagus Nerve Magnetic Stimulation in Patients With Traumatic Brain Injury: A Feasibility Study

OBJECTIVES

Transcutaneous vagus nerve stimulation has shown promising results in improving cognitive and motor function after stroke. However, to our knowledge, there have been no studies in the modulation of the cervical vagus nerve using repetitive transcranial magnetic stimulation (rTMS) in patients with traumatic brain injury (TBI) with cognitive dysfunction. Thus, we conducted a single-arm feasibility trial to assess the safety and effectiveness of rTMS of the vagus nerve in patients with TBI.

MATERIALS AND METHODS

We enrolled ten patients with TBI and administered half-hour vagus nerve magnetic stimulation (VNMS) sessions for ten days to evaluate the feasibility of the treatment. The Montreal cognitive assessment-Beijing (MoCA-B), the Digit Span Test, and the Auditory Verbal Learning Test (AVLT) were used to measure cognitive function before and after the VNMS treatment. Physiological parameters of all subjects were assessed by electrocardiogram.

RESULTS

The findings showed that daily half-hour VNMS for ten days was feasible in patients with TBI, with minimal side effects and no clinically significant effects on physiological parameters. Eight patients showed improvement in MoCA-B, and five patients showed improvement in immediate memory as measured by AVLT.

CONCLUSIONS

We conclude that VNMS is a safe and feasible treatment option for patients with TBI with cognitive dysfunction. However, further controlled studies are necessary to establish the efficacy of VNMS in promoting cognitive recovery after TBI.

SIGNIFICANCE

This study is, to our knowledge, the first study to investigate the feasibility of VNMS for cognitive dysfunction in patients with TBI. Our findings offer the possibility of rTMS applied to the vagus nerve in clinical practice.

A nomogram for predicting the necessity of tracheostomy after severe acute brain injury in patients within the neurosurgery intensive care unit: A retrospective cohort study

Objective

This retrospective study was aimed to develop a predictive model for assessing the necessity of tracheostomy (TT) in patients admitted to the neurosurgery intensive care unit (NSICU).

Method

We analyzed data from 1626 NSICU patients with severe acute brain injury (SABI) who were admitted to the Department of NSICU at the Affiliated People's Hospital of Jiangsu University between January 2021 and December 2022. Data of the patients were retrospectively obtained from the clinical research data platform. The patients were randomly divided into training (70%) and testing (30%) cohorts. The least absolute shrinkage and selection operator (LASSO) regression identified the optimal predictive features. A multivariate logistic regression model was then constructed and represented by a nomogram. The efficacy of the model was evaluated based on discrimination, calibration, and clinical utility.

Results

The model highlighted six predictive variables, including the duration of NSICU stay, neurosurgery, orotracheal intubation time, Glasgow Coma Scale (GCS) score, systolic pressure, and respiration rate. Receiver operating characteristic (ROC) analysis of the nomogram yielded area under the curve (AUC) values of 0.854 (95% confidence interval [CI]: 0.822-0.886) for the training cohort and 0.865 (95% CI: 0.817-0.913) for the testing cohort, suggesting commendable differential performance. The predictions closely aligned with actual observations in both cohorts. Decision curve analysis demonstrated that the numerical model offered a favorable net clinical benefit.

Conclusion

We developed a novel predictive model to identify risk factors for TT in SABI patients within the NSICU. This model holds the potential to assist clinicians in making timely surgical decisions concerning TT.

Identifying excessive chronic alcohol use with phosphatidylethanol in patients with suspected severe injury-results from the IDART study

INTRODUCTION

Acute and chronic alcohol use are well-known risk factors for accidents and injuries, and concurrent psychoactive drug use can increase injury risk further. Phosphatidylethanol (PEth) 16:0/18:1 is a biomarker used to determine alcohol consumption the previous 3-4 weeks. The aim was to investigate the prevalence of chronic alcohol use in trauma patients, as determined by PEth 16:0/18:1 concentrations, and how excessive chronic alcohol use relate to demographic variables, injury mechanisms and drug use.

SETTING

Patients received at Norwegian trauma hospitals from March 2019 to February 2020. The study is part of the Impairing Drugs and Alcohol as Risk factors for Traumatic Injuries study.

METHODS

All patients aged ≥ 16 years received with trauma team were included in the study. Data on injury date and mechanism, gender and age was registered. Blood samples were analyzed for 22 psychoactive medicinal and illicit drugs, ethanol and phosphatidylethanol 16:0/18:1. Regression analyses were conducted to assess associations between alcohol use and gender, age, injury mechanism and drug use.

RESULTS AND CONCLUSION

Of the 4845 patients included in the study, 10% had PEth 16:0/18:1 concentration ≥ 600 nM (~430 ng/mL), indicative of excessive chronic alcohol use. Being male, between 44-61 years old, involved in violence, and testing positive for medicinal drugs was associated with excessive chronic alcohol use.Excessive chronic alcohol use was common among males, middle-aged, patients with violence as injury mechanism and those with medicinal drug use. These findings emphasize the need to detect and treat excessive chronic alcohol use among trauma patients.

The effects of dexmedetomidine on trauma-induced secondary injury in rat brain

BACKGROUND

The objective of this study was to investigate the effect of dexmedetomidine (Dex), a sedative drug with little or no depressant effect on respiratory centers, on secondary injury in rat brain tissue by means of the Na+/K+ ATPase enzyme, which maintains the cell membrane ion gradient; malondialdehyde, an indicator of membrane lipid peroxidation; glutathione, an indicator of antioxidant capacity; and histopathological analyses.

METHODS

Eighteen rats were randomized into three groups: the trauma group received anesthesia, followed by head trauma with a Mild Traumatic Brain Injury Apparatus; the Trauma+Dex group received an additional treatment of 100 µg/kg intraperitoneal dexmedetomidine daily for three days; the Control group received anesthesia only.

RESULTS

The highest MDA levels compared to the Control group were found in the Trauma group. Mean levels in the Trauma+Dex group were lower, albeit still significantly high compared to the Control group. Glutathione levels were similar in all groups. Na/K-ATPase levels were significantly lower in the Trauma group compared to both the Control group and the Trauma+Dex group. Histopathologic findings of tissue degeneration including edema, vascular congestion and neuronal injury, and cleaved caspase-3 levels were lower in the Trauma+Dex group compared with the Trauma group.

CONCLUSIONS

Dexmedetomidine administered during the early stage of traumatic brain injury may inhibit caspase-3 cleavageHowever, the mechanism does not seem to be related to the improvement of MDA or GSH levels.

Prevention and treatment of traumatic brain injury-related delirium: a systematic review

BACKGROUND

Our systematic review examines the effectiveness and safety of non-pharmacologic and pharmacologic interventions in preventing or treating traumatic brain injury (TBI)-related delirium in acute care.

METHODS

We searched four electronic databases (MEDLINE, EMBASE, CENTRAL/CDSR, and PsycINFO) to identify randomized controlled trials (RCTs), quasi-experimental, and observational studies. Eligible studies included adults with TBI, at least one comparator group, delirium as an outcome and took place in acute care. Two reviewers independently completed all study screening, data abstraction, and risk of bias assessment using the Cochrane risk of bias 2 tool for RCTs or risk of bias in non-randomized studies-of interventions tool for observational studies. We implemented the PROGRESS-Plus framework to describe social determinants of health (SDoH) reporting.

RESULTS

We identified 20,022 citations, reviewed 301 in full text, and included eight studies in the descriptive synthesis. The mean age of study participants ranged from 32 to 62 years. 12.5% of included studies reported SDoH. Included studies had moderate-to-high risk of bias. Studies compared reorientation programs and an intervention bundle to usual care, but these interventions were not better than usual care in treating TBI-related delirium. Individual studies found that rosuvastatin and aripiprazole were more efficacious than placebo, and dexmedetomidine was more efficacious than propofol and haloperidol for preventing TBI-related delirium. No studies reported safety as the primary outcome.

CONCLUSIONS

We identified efficacious pharmacologic interventions for preventing TBI-related delirium, but these studies were at moderate-to-high risk of bias, which limits our confidence in these findings. Future studies should incorporate safety outcomes, and a diverse study population, including older adults.

Neurological Examination Frequency and Time-to-Delirium After Traumatic Brain Injury

BACKGROUND

Frequent neurological examinations in patients with traumatic brain injury (TBI) disrupt sleep-wake cycles and potentially contribute to the development of delirium.

OBJECTIVE

To evaluate the risk of delirium among patients with TBI with respect to their neuro-check frequencies.

METHODS

A retrospective study of patients presenting with TBI at a single level I trauma center between January 2018 and December 2019. The primary exposure was the frequency of neurological examinations (neuro-checks) assigned at the time of admission. Patients admitted with hourly (Q1) neuro-check frequencies were compared with those who received examinations every 2 (Q2) or 4 (Q4) hours. The primary outcomes were delirium and time-to-delirium. The onset of delirium was defined as the first documented positive Confusion Assessment Method for the Intensive Care Unit score.

RESULTS

Of 1552 patients with TBI, 458 (29.5%) patients experienced delirium during their hospital stay. The median time-to-delirium was 1.8 days (IQR: 1.1, 2.9). Kaplan-Meier analysis demonstrated that patients assigned Q1 neuro-checks had the greatest rate of delirium compared with the patients with Q2 and Q4 neuro-checks ( P < .001). Multivariable Cox regression modeling demonstrated that Q2 neuro-checks (hazard ratio: 0.439, 95% CI: 0.33-0.58) and Q4 neuro-checks (hazard ratio: 0.48, 95% CI: 0.34-0.68) were protective against the development of delirium compared with Q1. Other risk factors for developing delirium included pre-existing dementia, tobacco use, lower Glasgow Coma Scale score, higher injury severity score, and certain hemorrhage patterns.

CONCLUSION

Patients with more frequent neuro-checks had a higher risk of developing delirium compared with those with less frequent neuro-checks.

The establishment and validation of a prediction model for traumatic intracranial injury patients: a reliable nomogram

Objective

Traumatic brain injury (TBI) leads to death and disability. This study developed an effective prognostic nomogram for assessing the risk factors for TBI mortality.

Method

Data were extracted from an online database called "Multiparameter Intelligent Monitoring in Intensive Care IV" (MIMIC IV). The ICD code obtained data from 2,551 TBI persons (first ICU stay, >18 years old) from this database. R divided samples into 7:3 training and testing cohorts. The univariate analysis determined whether the two cohorts differed statistically in baseline data. This research used forward stepwise logistic regression after independent prognostic factors for these TBI patients. The optimal variables were selected for the model by the optimal subset method. The optimal feature subsets in pattern recognition improved the model prediction, and the minimum BIC forest of the high-dimensional mixed graph model achieved a better prediction effect. A nomogram-labeled TBI-IHM model containing these risk factors was made by nomology in State software. Least Squares OLS was used to build linear models, and then the Receiver Operating Characteristic (ROC) curve was plotted. The TBI-IHM nomogram model's validity was determined by receiver operating characteristic curves (AUCs), correction curve, Hosmer-Lemeshow test, integrated discrimination improvement (IDI), net reclassification improvement (NRI), and decision-curve analysis (DCA).

Result

The eight features with a minimal BIC model were mannitol use, mechanical ventilation, vasopressor use, international normalized ratio, urea nitrogen, respiratory rate, and cerebrovascular disease. The proposed nomogram (TBI-IHM model) was the best mortality prediction model, with better discrimination and superior model fitting for severely ill TBI patients staying in ICU. The model's receiver operating characteristic curve (ROC) was the best compared to the seven other models. It might be clinically helpful for doctors to make clinical decisions.

Conclusion

The proposed nomogram (TBI-IHM model) has significant potential as a clinical utility in predicting mortality in TBI patients.

Delirium in trauma ICUs: a review of incidence, risk factors, outcomes, and management

PURPOSE OF REVIEW

This article reviews the impact and importance of delirium on patients admitted to the ICU after trauma, including the latest work on prevention and treatment of this condition. As the population ages, the incidence of geriatric trauma will continue to increase with a concomitant rise in the patient and healthcare costs of delirium in this population.

RECENT FINDINGS

Recent studies have further defined the risk factors for delirium in the trauma ICU patient population, as well as better demonstrated the poor outcomes associated with the diagnosis of delirium in these patients. Recent trials and meta-analysis offer some new evidence for the use of dexmedetomidine and quetiapine as preferred agents for prevention and treatment of delirium and add music interventions as a promising part of nonpharmacologic bundles.

SUMMARY

Trauma patients requiring admission to the ICU are at significant risk of developing delirium, an acute neuropsychiatric disorder associated with increased healthcare costs and worse outcomes including increased mortality. Ideal methods for prevention and treatment of delirium are not well established, especially in this population, but recent research helps to clarify optimal prevention and treatment strategies.

The neuroprotective effect of dexmedetomidine and its mechanism

Dexmedetomidine (DEX) is a highly selective α2 receptor agonist that is routinely used in the clinic for sedation and anesthesia. Recently, an increasing number of studies have shown that DEX has a protective effect against brain injury caused by traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), cerebral ischemia and ischemia–reperfusion (I/R), suggesting its potential as a neuroprotective agent. Here, we summarized the neuroprotective effects of DEX in several models of neurological damage and examined its mechanism based on the current literature. Ultimately, we found that the neuroprotective effect of DEX mainly involved inhibition of inflammatory reactions, reduction of apoptosis and autophagy, and protection of the blood–brain barrier and enhancement of stable cell structures in five way. Therefore, DEX can provide a crucial advantage in neurological recovery for patients with brain injury. The purpose of this study was to further clarify the neuroprotective mechanisms of DEX therefore suggesting its potential in the clinical management of the neurological injuries.

Effect Evaluation of Dexmedetomidine Intravenous Anesthesia on Postoperative Agitation in Patients with Craniocerebral Injury by Magnetic Resonance Imaging Based on Sparse Reconstruction Algorithm

The effect of dexmedetomidine on postoperative agitation of patients with craniocerebral injury was investigated based on magnetic resonance imaging (MRI) with the sparse reconstruction algorithm. Sixty patients with craniocerebral injury who underwent tracheal intubation and craniotomy hematoma removal under general anesthesia in hospital were selected as the research objects. Patients were randomly and averagely divided into the normal saline group (group A) and the dexmedetomidine (DEX) group (group B). DEX was added to patients in group A during anesthesia. Other operations in group B were the same as those in group A, where DEX needed to be used was replaced by an equal amount of the normal saline. All patients received the MRI examination, and the images were processed by using the sparse reconstruction algorithm. After the surgery, some indexes, such as hemodynamics (mean arterial pressure (MAP) and hear rate (HR)), the Riker sedation agitation score, the Ramsay sedation score, and the visual analogue scale (VAS) score were recorded and compared. The results showed that the MRI image quality processed by sparse reconstruction algorithm was observably improved. After reconstruction, the sharpness of the image was significantly improved, and the distinction between lesions and tissues was also increased. The Riker sedation agitation score and the incidence of agitation in group A were greatly lower than those in group B (16% VS 76%, P < 0.05). The Ramsay sedation score of group A was manifestly higher than that of group B. The cases of postoperative nausea, vomiting, chills, delirium, and bradycardia in group A were 2, 1, 1, 0, and 1, respectively. The cases of postoperative nausea, vomiting, chills, delirium, and bradycardia in group B were 3, 9, 6, 5, and 0, respectively. The cases of chills and delirium in group A were observably less than those in group B (P < 0.05). In conclusion, based on the sparse reconstruction algorithm, the MRI technology and DEX had high adoption value in preventing postoperative agitation of patients with craniocerebral injury. Compared with group B, the hemodynamics of patients in group A was more stable.