Effects of Intracranial Pressure Monitoring on Mortality in Patients with Severe Traumatic Brain Injury: A Meta-Analysis

A deep learning approach for generating intracranial pressure waveforms from extracranial signals routinely measured in the intensive care unit

Intracranial pressure (ICP) is commonly monitored to guide treatment in patients with serious brain disorders such as traumatic brain injury and stroke. Established methods to assess ICP are resource intensive and highly invasive. We hypothesized that ICP waveforms can be computed noninvasively from three extracranial physiological waveforms routinely acquired in the Intensive Care Unit (ICU): arterial blood pressure (ABP), photoplethysmography (PPG), and electrocardiography (ECG). We evaluated over 600 h of high-frequency (125 Hz) simultaneously acquired ICP, ABP, ECG, and PPG waveform data in 10 patients admitted to the ICU with critical brain disorders. The data were segmented in non-overlapping 10-s windows, and ABP, ECG, and PPG waveforms were used to train deep learning (DL) models to re-create concurrent ICP. The predictive performance of six different DL models was evaluated in single- and multi-patient iterations. The mean average error (MAE) ± SD of the best-performing models was 1.34 ± 0.59 mmHg in the single-patient and 5.10 ± 0.11 mmHg in the multi-patient analysis. Ablation analysis was conducted to compare contributions from single physiologic sources and demonstrated statistically indistinguishable performances across the top DL models for each waveform (MAE±SD 6.33 ± 0.73, 6.65 ± 0.96, and 7.30 ± 1.28 mmHg, respectively, for ECG, PPG, and ABP; p = 0.42). Results support the preliminary feasibility and accuracy of DL-enabled continuous noninvasive ICP waveform computation using extracranial physiological waveforms. With refinement and further validation, this method could represent a safer and more accessible alternative to invasive ICP, enabling assessment and treatment in low-resource settings.

Intracranial pressure monitoring for severe traumatic brain injury: A retrospective study of 273 consecutive patients

Background

Intracranial pressure (ICP) monitoring is essential in severe traumatic brain injury (sTBI) cases; yet, the frequency of high ICP occurrences remains debated. This study presents a 9-year analysis of ICP monitoring using intraventricular catheters among sTBI patients.

Methods

A retrospective review of 1760 sTBI patients (Glasgow Coma Score <9) admitted between January 2011 and December 2019 was conducted. Of these, 280 patients meeting monitoring criteria were included based on Brain Trauma Foundation (BTF) Guidelines. ICP was monitored using intraventricular catheters through right frontal burr holes. Initial ICP readings were recorded intraoperatively, followed by continuous monitoring. Patients with ICP >20 mmHg for 10-15 min during 72 h were categorized with high ICP. Data collected included demographics, computed tomography (CT) findings, intra- and post-operative ICP, and complications.

Results

Of 273 patients, 228 were male and 45 females, aged 18-80 (71.30% aged 18-45). Traffic accidents were the primary cause (90.48%). Fifty-two-point seventy-five percent experienced high ICP, correlating significantly with subdural hematoma (P < 0.001), intraventricular hemorrhage (P < 0.013), and compressed basal cisterns (P = 0.046) on initial CT. Twenty patients (7.3%) developed meningitis. Lower mortality rates and improved outcomes were observed in the low ICP group across discharge 3-and 6-month follow-ups.

Conclusion

Adherence to BTF guidelines yielded a 52.75% high ICP rate. Significant correlations were found between high ICP and specific CT abnormalities. This study underscores the benefits of ICP monitoring in selected sTBI cases, suggesting a need to review criteria for initiating monitoring protocols.

The recent two decades of traumatic brain injury: a bibliometric analysis and systematic review

BACKGROUND

Traumatic brain injury (TBI) is a serious public health burden worldwide, with a mortality rate of 20-30%; however, reducing the incidence and mortality rates of TBI remains a major challenge. This study provides a multidimensional analysis to explore the potential breakthroughs in TBI over the past two decades.

MATERIALS AND METHODS

The authors used bibliometric and Latent Dirichlet Allocation (LDA) analyses to analyze publications focusing on TBI published between 2003 and 2022 from the Web of Science Core Collection (WOSCC) database to identify core journals and collaborations among countries/regions, institutions, authors, and research trends.

RESULTS

Over the past 20 years, 41 545 articles on TBI from 3043 journals were included, with 12 916 authors from 20 449 institutions across 145 countries/regions. The annual number of publications has increased 10-fold compared to previous publications. This study revealed that high-income countries, especially the United States, have a significant influence. Collaboration was limited to several countries/regions. The LDA results indicated that the hotspots included four main areas: 'Clinical finding', 'Molecular mechanism', 'Epidemiology', and 'Prognosis'. Epidemiological research has consistently increased in recent years. Through epidemiological topic analysis, the main etiology of TBI has shifted from traffic accidents to falls in a demographically aging society.

CONCLUSION

Over the past two decades, TBI research has developed rapidly, and its epidemiology has received increasing attention. Reducing the incidence of TBI from a preventive perspective is emerging as a trend to alleviate the future social burden; therefore, epidemiological research might bring breakthroughs in TBI.

A Comprehensive Perspective on Intracranial Pressure Monitoring and Individualized Management in Neurocritical Care: Results of a Survey with Global Experts

BACKGROUND

Numerous trials have addressed intracranial pressure (ICP) management in neurocritical care. However, identifying its harmful thresholds and controlling ICP remain challenging in terms of improving outcomes. Evidence suggests that an individualized approach is necessary for establishing tolerance limits for ICP, incorporating factors such as ICP waveform (ICPW) or pulse morphology along with additional data provided by other invasive (e.g., brain oximetry) and noninvasive monitoring (NIM) methods (e.g., transcranial Doppler, optic nerve sheath diameter ultrasound, and pupillometry). This study aims to assess current ICP monitoring practices among experienced clinicians and explore whether guidelines should incorporate ancillary parameters from NIM and ICPW in future updates.

METHODS

We conducted a survey among experienced professionals involved in researching and managing patients with severe injury across low-middle-income countries (LMICs) and high-income countries (HICs). We sought their insights on ICP monitoring, particularly focusing on the impact of NIM and ICPW in various clinical scenarios.

RESULTS

From October to December 2023, 109 professionals from the Americas and Europe participated in the survey, evenly distributed between LMIC and HIC. When ICP ranged from 22 to 25 mm Hg, 62.3% of respondents were open to considering additional information, such as ICPW and other monitoring techniques, before adjusting therapy intensity levels. Moreover, 77% of respondents were inclined to reassess patients with ICP in the 18-22 mm Hg range, potentially escalating therapy intensity levels with the support of ICPW and NIM. Differences emerged between LMIC and HIC participants, with more LMIC respondents preferring arterial blood pressure transducer leveling at the heart and endorsing the use of NIM techniques and ICPW as ancillary information.

CONCLUSIONS

Experienced clinicians tend to personalize ICP management, emphasizing the importance of considering various monitoring techniques. ICPW and noninvasive techniques, particularly in LMIC settings, warrant further exploration and could potentially enhance individualized patient care. The study suggests updating guidelines to include these additional components for a more personalized approach to ICP management.

Problematic meta-analyses: Bayesian and frequentist perspectives on combining randomized controlled trials and non-randomized studies

PURPOSE

In the literature, the propriety of the meta-analytic treatment-effect produced by combining randomized controlled trials (RCT) and non-randomized studies (NRS) is questioned, given the inherent confounding in NRS that may bias the meta-analysis. The current study compared an implicitly principled pooled Bayesian meta-analytic treatment-effect with that of frequentist pooling of RCT and NRS to determine how well each approach handled the NRS bias.

MATERIALS & METHODS

Binary outcome Critical-Care meta-analyses, reflecting the importance of such outcomes in Critical-Care practice, combining RCT and NRS were identified electronically. Bayesian pooled treatment-effect and 95% credible-intervals (BCrI), posterior model probabilities indicating model plausibility and Bayes-factors (BF) were estimated using an informative heavy-tailed heterogeneity prior (half-Cauchy). Preference for pooling of RCT and NRS was indicated for Bayes-factors > 3 or < 0.333 for the converse. All pooled frequentist treatment-effects and 95% confidence intervals (FCI) were re-estimated using the popular DerSimonian-Laird (DSL) random effects model.

RESULTS

Fifty meta-analyses were identified (2009-2021), reporting pooled estimates in 44; 29 were pharmaceutical-therapeutic and 21 were non-pharmaceutical therapeutic. Re-computed pooled DSL FCI excluded the null (OR or RR = 1) in 86% (43/50). In 18 meta-analyses there was an agreement between FCI and BCrI in excluding the null. In 23 meta-analyses where FCI excluded the null, BCrI embraced the null. BF supported a pooled model in 27 meta-analyses and separate models in 4. The highest density of the posterior model probabilities for 0.333 < Bayes factor < 1 was 0.8.

CONCLUSIONS

In the current meta-analytic cohort, an integrated and multifaceted Bayesian approach gave support to including NRS in a pooled-estimate model. Conversely, caution should attend the reporting of naïve frequentist pooled, RCT and NRS, meta-analytic treatment effects.

Patterns and outcomes of intracranial pressure monitoring in traumatic brain injury: An analysis of the National Inpatient Sample

INTRODUCTION

Elevated intracranial pressure (ICP) can cause progressive neurological deterioration following traumatic brain injury (TBI). ICP can be monitored to guide subsequent treatment decisions. However, there is conflicting data in the literature regarding the utility of ICP monitoring. We aim to describe patterns and outcomes of ICP monitoring in the United States with the use of a nationwide healthcare database.

METHODS

We performed a 5-year analysis of the Nationwide Inpatient Sample database. We identified all adult TBI patients with a Glasgow Coma Scale (GCS) measuring 3-8 using International Classification of Diseases diagnostic codes. Propensity score matching (1:2 ratio) was performed to control for demographics, injury parameters and comorbidities. Outcome measures included inpatient mortality, length of stay (LOS), cost of care, and discharge disposition.

RESULTS

After propensity score matching, a cohort of 1664 patients was obtained (monitored, 555; non-monitored, 1109). Index outcomes with respect to monitor and no-monitor are as follows: inpatient mortality (35.1%, 42.4%, P <0.01), median LOS (15 days, 6 days, P<0.001), median total charge (289,797 USD, 154,223 USD, P <0.001), discharge home (7.9%, 19.3%, P <0.001) and discharge to another facility (53.9%, 35.4%, P <0.001).

DISCUSSION

ICP monitoring in TBI patients is associated with decreased inpatient mortality and discharge to home, and it is associated with an increased hospital LOS, total charge, and chance of discharge to another facility.

CONCLUSION

The risks and benefits of ICP monitoring should be seriously considered when managing adults with severe TBI.

A pilot clinical study to estimate intracranial pressure utilising cerebral photoplethysmograms in traumatic brain injury patients

PURPOSE

In this research, a non-invasive intracranial pressure (nICP) optical sensor was developed and evaluated in a clinical pilot study. The technology relied on infrared light to probe brain tissue, using photodetectors to capture backscattered light modulated by vascular pulsations within the brain's vascular tissue. The underlying hypothesis was that changes in extramural arterial pressure could affect the morphology of recorded optical signals (photoplethysmograms, or PPGs), and analysing these signals with a custom algorithm could enable the non-invasive calculation of intracranial pressure (nICP).

METHODS

This pilot study was the first to evaluate the nICP probe alongside invasive ICP monitoring as a gold standard. nICP monitoring occurred in 40 patients undergoing invasive ICP monitoring, with data randomly split for machine learning. Quality PPG signals were extracted and analysed for time-based features. The study employed Bland-Altman analysis and ROC curve calculations to assess nICP accuracy compared to invasive ICP data.

RESULTS

Successful acquisition of cerebral PPG signals from traumatic brain injury (TBI) patients allowed for the development of a bagging tree model to estimate nICP non-invasively. The nICP estimation exhibited 95% limits of agreement of 3.8 mmHg with minimal bias and a correlation of 0.8254 with invasive ICP monitoring. ROC curve analysis showed strong diagnostic capability with 80% sensitivity and 89% specificity.

CONCLUSION

The clinical evaluation of this innovative optical nICP sensor revealed its ability to estimate ICP non-invasively with acceptable and clinically useful accuracy. This breakthrough opens the door to further technological refinement and larger-scale clinical studies in the future.

TRIAL REGISTRATION

NCT05632302, 11th November 2022, retrospectively registered.

Brain Regional Energy Metabolism in Patients with Traumatic Brain Injury: A Cerebral Microdialysis Guided Study

BACKGROUND

In traumatic brain injuries (TBI), cerebral microdialysis (CMD)-derived parameters, especially the lactate to pyruvate ratio (LP ratio), have been utilized for cerebral perfusion optimization. The objectives were to identify cerebral ischemia as measured by CMD in TBI patients requiring decompressive craniectomy and to observe the correlation between cerebral perfusion pressure (CPP), intracranial pressure (ICP), and CMD variables in these patients. Our secondary aim was to observe the effect of CPP augmentation on ischemia biomarkers.

METHODS

After the Institute Ethics Committee approvals, seven adult patients requiring decompressive craniectomy following TBI were enrolled and CMD data were obtained prospectively for 72 h. CPP was augmented by 20% with noradrenaline infusion if LP ratio >40. Correlations were done with bootstrapping (n = 500) to obtain the confidence intervals (CI) due to the small sample size.

RESULTS

One patient had cerebral ischemia (median LP ratio of 265.5 and median pyruvate of 38 μmol/L), while another patient had non-ischemic mitochondrial dysfunction (median LP ratio 40.7 and median pyruvate 278.5). The coefficients of correlation between the LP ratio with CPP and ICP were r = -0.05 (CI = -0.14-0.03) and r = 0.09 (CI = -0.03-0.24), respectively. The coefficient of correlation between cerebral and blood glucose was r = 0.38, (CI - 0.35-0.14). Only two patients needed CPP augmentation, however, postaugmentation cerebral biochemistry did not change appreciably.

CONCLUSION

CMD can identify cerebral ischemia, however, no correlations were observed between the LP ratio and CPP or ICP. CPP augmentation did not improve cerebral biochemistry. More studies are required to understand and treat cerebral metabolism in TBI.

The effect of age on clinical outcomes in critically ill brain-injured patients

PURPOSE

We studied the impact of age on survival and functional recovery in brain-injured patients.

METHODS

We performed an observational cohort study of all consecutive adult patients with brain injury admitted to ICU in 8 years. To estimate the optimal cut-off point of the age associated with unfavorable outcomes (mRS 3-6), receiver operating characteristic (ROC) curve analyses were used. Multivariate logistic regression analyses were performed to identify prognostic factors for unfavorable outcomes.

RESULTS

We included 619 brain-injured patients. We identified 60 years as the cut-off point at which the probability of unfavorable outcomes increases. Patients ≥ 60 years had higher severity scores at ICU admission, longer duration of mechanical ventilation, longer ICU and hospital stays, and higher mortality. Factors identified as associated with unfavorable outcomes (mRS 3-6) were an advanced age (≥ 60 years) [Odds ratio (OR) 4.59, 95% confidence interval (CI) 2.73-7.74, p < 0.001], a low GCS score (≤ 8 points) [OR 3.72, 95% CI 1.95-7.08, p < 0.001], the development of intracranial hypertension [OR 5.52, 95% CI 2.70-11.28, p < 0.001], and intracerebral hemorrhage as the cause of neurologic disease [OR 3.87, 95% CI 2.34-6.42, p < 0.001].

CONCLUSION

Mortality and unfavorable functional outcomes in critically ill brain-injured patients were associated with older age (≥ 60 years), higher clinical severity (determined by a lower GCS score at admission and the development of intracranial hypertension), and an intracerebral hemorrhage as the cause of neurologic disease.

Intracranial Hypertension following Acute Mesenteric Ischemia: A Case Study on the Multiple Compartment Syndrome

In this case study, we describe a 25-year-old male who was admitted due to a severe traumatic brain injury, requiring invasive intracranial pressure monitoring. At 48 hours posttrauma, he developed intracranial hypertension refractory to medical treatment without tomographic changes in the brain. Subsequently, intra-abdominal hypertension and tomographic signs of abdominal surgical pathology were observed. An exploratory laparotomy was performed with an intraoperative diagnosis of acute mesenteric ischemia. After surgical intervention for the abdominal pathology, intracranial pressure was restored to physiological values with a favorable recovery of the patient. In this report, the relationship between intracranial pressure and intra-abdominal pressure is discussed, highlighting the delicate association between the brain, abdomen, and thorax. Measures should be taken to avoid increases in intra-abdominal pressure in neurocritical patients. When treating intracranial hypertension refractory to conventional measures, abdominal causes and multiple compartment syndrome must be considered. The cranial compartment has physiological interdependence with other body compartments, where one can be modified by variations from another, giving rise to the concept of multiple compartment syndrome. Understanding this relationship is fundamental for a comprehensive approach of the neurocritical patient. To the best of our knowledge, this is the first report of a comatose patient post-traumatic brain injury, who developed medically unresponsive intracranial hypertension secondary to acute mesenteric ischemia, in which surgical resolution of intra-abdominal pathology resulted in intracranial pressure normalization and restitutio ad integrum of neurological status.

Ultrasound detected increase in optic disk height to identify elevated intracranial pressure: a systematic review

BACKGROUND

Elevated intracranial pressure (eICP) is a serious medical emergency that requires prompt identification and monitoring. The current gold standards of eICP detection require patient transportation, radiation, and can be invasive. Ocular ultrasound has emerged as a rapid, non-invasive, bedside tool to measure correlates of eICP. This systematic review seeks to explore the utility of ultrasound detected optic disc elevation (ODE) as an ultrasonographic finding of eICP and to study its sensitivity and specificity as a marker of eICP.

METHODS

This systematic review followed the preferred reporting items for systematic reviews and meta-analyses guidelines. We systematically searched PubMed, EMBASE, and Cochrane Central for English articles published before April 2023; yielding 1,919 total citations. After eliminating duplicates, and screening the records, we identified 29 articles that addressed ultrasonographically detected ODE.

RESULTS

The 29 articles included a total of 1249 adult and pediatric participants. In patients with papilledema, the mean ODE ranged between 0.6 mm and 1.2 mm. Proposed cutoff values for ODE ranged between 0.3 mm and 1 mm. The majority of studies reported a sensitivity between 70 and 90%, and specificity ranged from 69 to 100%, with a majority of studies reporting a specificity of 100%.

CONCLUSIONS

ODE and ultrasonographic characteristics of the optic disc may aid in differentiating papilledema from other conditions. Further research on ODE elevation and its correlation with other ultrasonographic signs is warranted as a means to increase the diagnostic accuracy of ultrasound in the setting of eICP.

Optic nerve sheath diameter, intensive care unit admission and COVID-19-related-in-hospital mortality

BACKGROUND

Hypoxia and hypercapnia due to acute pulmonary failure in patients with coronavirus disease 2019 (COVID-19) can increase the intracranial pressure (ICP). ICP correlated with the optic nerve sheath diameter (ONSD) on ultrasonography and is associated with a poor prognosis.

AIM

We investigated the capability of ONSD measured during admission to the intensive care unit (ICU) in patients with critical COVID-19 in predicting in-hospital mortality.

METHODS

A total of 91 patients enrolled in the study were divided into two groups: survivor (n = 48) and nonsurvivor (n = 43) groups. ONSD was measured by ultrasonography within the first 3 h of ICU admission.

RESULTS

The median ONSD was higher in the nonsurvivor group than in the survivor group (5.95 mm vs. 4.15 mm, P < 0.001). The multivariate Cox proportional hazard regression analysis between ONSD and in-hospital mortality (contains 26 covariates) was significant (adjusted hazard ratio, 4.12; 95% confidence interval, 1.46-11.55; P = 0.007). The ONSD cutoff for predicting mortality during ICU admission was 5 mm (area under the curve, 0.985; sensitivity, 98%; and specificity, 90%). The median survival of patients with ONSD >5 mm (43%; n = 39) was lower than those with ONSD ≤5 mm (57%; n = 52) (11.5 days vs. 13.2 days; log-rank test P = 0.001).

CONCLUSIONS

ONSD ultrasonography during ICU admission may be an important, cheap and easy-to-apply method that can be used to predict mortality in the early period in patients with critical COVID-19.

Decompressive Hemicraniectomies as a Damage Control Approach for Multilobar Firearm Projectile Injuries: A Single-Center Experience

BACKGROUND

While firearms projectile injuries to the head carry a high rate of morbidity and mortality, current literature in clinical management remains controversial. Decompressive hemicraniectomy (DHC) has been previously described in the neurosurgical literature for traumatic brain injuries, with positive results in the reduction of mortality. Here we aim to assess DHC as a damage control approach for multilobar firearm injuries to the head and compare our results with what is present in the literature.

METHODS

A retrospective review of patients who sustained multilobar firearm injuries to the head admitted to our center from January 2009 to April 2021 was performed. Exclusion criteria were a Glasgow Coma Scale (GCS) score <5, and/or brain stem dysfunction that persisted despite stabilization and medical therapy for intracranial hypertension.

RESULTS

A total of 20 patients were analyzed, with an average GCS on admission of 8.35. The 60-day mortality rate for all 20 patients was 20% with a total of 4 deaths, 1 of which was due to pulmonary sepsis in the critical postoperative care unit. The mean hospital stay of surviving patients was 22 days.

CONCLUSIONS

DHC should be considered as a damage control strategy for young patients with multilobar firearm injuries and GCS >5, having yielded favorable results in this study when compared to current literature.

Characteristics and therapeutic profile of TBI patients who underwent bilateral decompressive craniectomy: experience with 151 cases

Background

Decompressive craniectomy (DC) and intracranial pressure (ICP) monitoring are common approaches to reduce the death rate of Traumatic brain injury (TBI) patients, but the outcomes of these patients are unfavorable, particularly those who receive bilateral DC. The authors discuss their experience using ICP and other potential methods to improve the outcomes of TBI patients who receive bilateral DC.

Methods

Data from TBI patients receiving bilateral DC from Jan. 2008 to Jan. 2022 were collected via a retrospective chart review. Included patients who received unplanned contralateral DC after initial surgery were identified as unplanned secondary surgery (USS) patients. Patients’ demographics and baseline medical status; pre-, intra-, and postoperative events; and follow-up visit outcome data were analyzed.

Results

A total of 151 TBI patients were included. Patients who underwent USS experienced more severe outcomes as assessed using the 3-month modified Rankin Scale score (P = 0.024). In bilateral DC TBI patients, USS were associated with worsen outcomes, moreover, ICP monitoring was able to lower their death rate and was associated with a lower USS incidence. In USS patients, ICP monitoring was not associated with improved outcomes but was able to lower their mortality rate (2/19, 10.5%, vs. 10/25, 40.0%; P = 0.042).

Conclusion

The avoidance of USS may be associated with improved outcomes of TBI patients who underwent bilateral DC. ICP monitoring was a potential approach to lower USS rate in TBI patients, but its specific benefits were uncertain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-022-01046-w.

The Significance of Intracranial Pressure Monitoring for Reducing Mortality in Patients with Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Background

Despite guidelines provided by the Brain Trauma Foundation (BTF) for treating patients with TBI, including advice to monitor intracranial pressure (ICP), the clinical application of ICP monitoring is far from universal. This laxity has been attributed to the relationship between mortality in TBI patients and ICP monitoring.

Objective

This systematic review and meta-analysis was aimed at determining the effect of intracranial pressure (ICP) monitoring on the mortality of patients with traumatic brain injury (TBI).

Method

A systematic search for articles was conducted on PubMed, Scopus, Cochrane Central Register of Control Trials (CENTRAL), and APA PsycNet for articles published from 1 January 2000 to 1 August 2022. Manager 5.4 was used to carry out statistical analysis.

Results

Article search yielded 1421 articles, but only 23 cohort studies were included in the systematic review and meta-analysis. The total number of study participants is 80,058. Seventeen studies reported unadjusted odds ratios (OR), and only 8 reported the adjusted odds ratio (OR). Nine out of seventeen studies reported an unadjusted OR of less than 1, and five out of eight studies reported an adjusted OR of less than 1. From this paper's analysis, the OR for in-hospital mortality was 1.01 [95% CI, 0.80, 1.28], with a p value of 0.92. OR for ICU mortality was 0.84 [95% CI, 0.52, 1.35], with a p value of 0.47.

Conclusion

But due to conflicting results, as evident above, it is unsatisfyingly challenging to draw any substantial conclusions from them. This paper thus calls for more research on this particular paper.

Initial neurocritical care of severe traumatic brain injury: New paradigms and old challenges

Background:

Early neurocritical care aims to ameliorate secondary traumatic brain injury (TBI) and improve neural salvage. Increased engagement of neurosurgeons in neurocritical care is warranted as daily briefings between the intensivist and the neurosurgeon are considered a quality indicator for TBI care. Hence, neurosurgeons should be aware of the latest evidence in the neurocritical care of severe TBI (sTBI).

Methods:

We conducted a narrative literature review of bibliographic databases (PubMed and Scopus) to examine recent research of sTBI.

Results:

This review has several take-away messages. The concept of critical neuroworsening and its possible causes is discussed. Static thresholds of intracranial pressure (ICP) and cerebral perfusion pressure may not be optimal for all patients. The use of dynamic cerebrovascular reactivity indices such as the pressure reactivity index can facilitate individualized treatment decisions. The use of ICP monitoring to tailor treatment of intracranial hypertension (IHT) is not routinely feasible. Different guidelines have been formulated for different scenarios. Accordingly, we propose an integrated algorithm for ICP management in sTBI patients in different resource settings. Although hyperosmolar therapy and decompressive craniectomy are standard treatments for IHT, there is a lack high-quality evidence on how to use them. A discussion of the advantages and disadvantages of invasive ICP monitoring is included in the study. Addition of beta-blocker, anti-seizure, and anticoagulant medications to standardized management protocols (SMPs) should be considered with careful patient selection.

Conclusion:

Despite consolidated research efforts in the refinement of SMPs, there are still many unanswered questions and novel research opportunities for sTBI care.

Impact of Intracranial Hypertension on Outcome of Severe Traumatic Brain Injury Pediatric Patients: A 15-Year Single Center Experience

Background: Intracranial hypertension (IC-HTN) is significantly associated with higher risk for an unfavorable outcome in pediatric trauma. Intracranial pressure (ICP) monitoring is widely becoming a standard of neurocritical care for children. Methods: The present study was designed to evaluate influences of IC-HTN on clinical outcomes of pediatric TBI patients. Demographic, injury severity, radiologic characteristics were used as possible predictors of IC-HTN or of functional outcome. Results: A total of 118 pediatric intensive care unit (PICU) patients with severe TBI (sTBI) were included. Among sTBI cases, patients with GCS < 5 had significantly higher risk for IC-HTN and for mortality. Moreover, there was a statistically significant positive correlation between IC-HTN and severity scoring systems. Kaplan−Meier analysis determined a significant difference for good recovery among patients who had no ICP elevations, compared to those who had at least one episode of IC-HTN (log-rank chi-square = 11.16, p = 0.001). A multivariable predictive logistic regression analysis distinguished the ICP-monitored patients at risk for developing IC-HTN. The model finally revealed that higher ISS and Helsinki CT score increased the odds for developing IC-HTN (p < 0.05). Conclusion: The present study highlights the importance of ICP-guided clinical practices, which may lead to increasing percentages of good recovery for children.

Intracranial Pressure Monitoring in the Intensive Care Unit for Patients with Severe Traumatic Brain Injury: Analysis of the CENTER-TBI China Registry

BACKGROUND

Although the current guidelines recommend the use of intracranial pressure (ICP) monitoring in patients with severe traumatic brain injury (sTBI), the evidence indicating benefit is limited. The present study aims to evaluate the impact of ICP monitoring on patients with sTBI in the intensive care unit (ICU).

METHODS

The patient data were obtained from the Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury China Registry, a prospective, multicenter, longitudinal, observational, cohort study. Patients with sTBI who were admitted to 52 ICUs across China, managed with ICP monitoring or without, were analyzed in this study. Patients with missing information on discharge survival status, Glasgow Coma Scale score on admission to hospital, and record of ICP monitoring application were excluded from the analysis. Data on demographic characteristics, injury, clinical features, treatments, survival at discharge, discharge destination, and length of stay were collected and assessed. The primary end point was survival state at discharge, and death from any cause was considered the event of interest.

RESULTS

A total of 2029 patients with sTBI were admitted to the ICU; 737 patients (36.32%) underwent ICP monitoring, and 1292 (63.68%) were managed without ICP monitoring. There was a difference between management with and without ICP monitoring on in-hospital mortality in the unmatched cohort (18.86% vs. 26.63%, p < 0.001) and the propensity-score-matched cohort (19.82% vs. 26.83%, p = 0.003). Multivariate logistic regressions also indicated that increasing age, higher injury severity score, lower Glasgow Coma Scale score, unilateral and bilateral pupillary abnormalities, systemic hypotension (SBP ≤ 90 mm Hg), hypoxia (SpO2 < 95%) on arrival at the hospital, and management without ICP monitoring were associated with higher in-hospital mortality. However, the patients without ICP monitoring had a lower length of stay in the ICU (11.79 vs. 7.95 days, p < 0.001) and hospital (25.96 vs. 21.71 days, p < 0.001), and a higher proportion of survivors were discharged to the home with better recovery in self-care.

CONCLUSIONS

Although ICP monitoring was not widely used by all of the centers participating in this study, patients with sTBI managed with ICP monitoring show a better outcome in overall survival. Nevertheless, the use of ICP monitoring makes the management of sTBI more complex and increases the costs of medical care by prolonging the patient's stay in the ICU or hospital.

The ICEBERG: a score and visual representation to track the severity of traumatic brain injury: design principles and preliminary results

BACKGROUND

Establishing neurological prognoses in traumatic brain injury (TBI) patients remains challenging. To help physicians in the early management of severe TBI, we have designed a visual score (ICEBERG score) including multimodal monitoring and treatment-related criteria. We evaluated the ICEBERG scores among patients with severe TBI to predict the 28-day mortality and long-term disability (Extended Glasgow Outcome Score (GOSE) at 3 years). Additionally, we made a preliminary assessment of the nurses and doctors on the uptake and reception to the use of the ICEBERG visual tool.

METHODS

This study was part of a larger prospective cohort study of 207 patients with severe TBI in the Parisian region (PariS-TBI study). The ICEBERG score included 6 variables from multimodal monitoring and treatment-related criteria: cerebral perfusion pressure (CPP), intracranial pressure (ICP), body temperature, sedation depth, arterial partial pressure of CO2 and blood osmolarity. The primary outcome measures included the ICEBERG score and its relationship with hospital mortality and GOSE.

RESULTS

The hospital mortality was 21% (45/207). The ICEBERG score baseline value and changes during the 72nd first hours were more strongly associated with TBI prognosis than the ICEBERG parameters measured individually. Interestingly, when the clinical and CT parameters at admission were combined with the ICEBERG score at 48 h using a multimodal approach, the predictive value was significantly increased (AUC = 0.92). Furthermore, comparing the ICEBERG visual representation with the traditional numerical readout revealed that changes in patient vitals were more promptly detected using ICEBERG representation (p < 0.05).

CONCLUSIONS

The ICEBERG score could represent a simple and effective method to describe severity in TBI patients, where a high score is associated with increased mortality and disability. Additionally, ICEBERG representation could enhances the recognition of unmet therapeutic goals and dynamic evolution of the patient's condition. These preliminary results must be confirmed in a prospective manner.

STUDY TYPE

Prognostic.

LEVEL OF EVIDENCE

Level III.

Controversies and evidence gaps in the early management of severe traumatic brain injury: back to the ABCs

Traumatic brain injury (TBI) accounts for around 30% of all trauma-related deaths. Over the past 40 years, TBI has remained a major cause of mortality after trauma. The primary injury caused by the injurious mechanical force leads to irreversible damage to brain tissue. The potentially preventable secondary injury can be accentuated by addressing systemic insults. Early recognition and prompt intervention are integral to achieve better outcomes. Consequently, surgeons still need to be aware of the basic yet integral emergency management strategies for severe TBI (sTBI). In this narrative review, we outlined some of the controversies in the early care of sTBI that have not been settled by the publication of the Brain Trauma Foundation’s 4th edition guidelines in 2017. The topics covered included the following: mode of prehospital transport, maintaining airway patency while securing the cervical spine, achieving adequate ventilation, and optimizing circulatory physiology. We discuss fluid resuscitation and blood product transfusion as components of improving circulatory mechanics and oxygen delivery to injured brain tissue. An outline of evidence-based antiplatelet and anticoagulant reversal strategies is discussed in the review. In addition, the current evidence as well as the evidence gaps for using tranexamic acid in sTBI are briefly reviewed. A brief note on the controversial emergency surgical interventions for sTBI is included. Clinicians should be aware of the latest evidence for sTBI. Periods between different editions of guidelines can have an abundance of new literature that can influence patient care. The recent advances included in this review should be considered both for formulating future guidelines for the management of sTBI and for designing future clinical studies in domains with clinical equipoise.

Ultrasound measurement of the optic nerve sheath diameter in traumatic brain injury: a narrative review

Background : Raised intracranial pressure (ICP) needs to be investigated in various situations, especially in traumatic brain injury (TBI). Ultra-sonographic (US) measurement of the optic nerve sheath diameter (ONSD) is a promising noninvasive tool for assessing elevated ICP. Objectives : This narrative review aimed to explain the history of and indications forUS measurement of ONSD. We focused on the detection of elevated ICP after TBI and discussed the possible improvements in detection methods. Conclusions : US measurement of ONSD in TBI cases provides a qualitative but no quantitative assessment of ICP. Current studies usually calculate their own optimum cutoff value for detecting raised ICP based on the balance between sensitivity and specificity of the method when compared with invasive methods. There is no universally accepted threshold. We did not find any paper focusing on the prognosis of patients benefiting from it when compared with usual care. Another limitation is the lack of standardization. US measurement of ONSD cannot be used as the sole technique to detect elevated ICP and monitor its evolution, but it can be a useful tool in a multimodal protocol and it might help to determine the prognosis of patients in various situations.

Factors associated with receipt of intracranial pressure monitoring in older adults with traumatic brain injury

BACKGROUND

The Brain Trauma Foundation (BTF) Guidelines for the Management of Severe Traumatic Brain Injury (TBI) include intracranial pressure monitoring (ICPM), yet very little is known about ICPM in older adults. Our objectives were to characterize the utilization of ICPM in older adults and identify factors associated with ICPM in those who met the BTF guidelines.

METHODS

We analyzed data from the American Association for the Surgery of Trauma Geriatric TBI Study, a registry study conducted among individuals with isolated, CT-confirmed TBI across 45 trauma centers. The analysis was restricted to those aged ≥60. Independent factors associated with ICPM for those who did and did not meet the BTF guidelines were identified using logistic regression.

RESULTS

Our sample was composed of 2303 patients, of whom 66 (2.9%) underwent ICPM. Relative to Glasgow Coma Scale (GCS) score of 13 to 15, GCS score of 9 to 12 (OR 10.2; 95% CI 4.3 to 24.4) and GCS score of <9 (OR 15.0; 95% CI 7.2 to 31.1), intraventricular hemorrhage (OR 2.4; 95% CI 1.2 to 4.83), skull fractures (OR 3.6; 95% CI 2.0 to 6.6), CT worsening (OR 3.3; 95% CI 1.8 to 5.9), and neurosurgical interventions (OR 3.8; 95% CI 2.1 to 7.0) were significantly associated with ICPM. Restricting to those who met the BTF guidelines, only 43 of 240 (18%) underwent ICPM. Factors independently associated with ICPM included intraparenchymal hemorrhage (OR 2.2; 95% CI 1.0 to 4.7), skull fractures (OR 3.9; 95% CI 1.9 to 8.2), and neurosurgical interventions (OR 3.5; 95% CI 1.7 to 7.2).

DISCUSSION

Worsening GCS, intraparenchymal/intraventricular hemorrhage, and skull fractures were associated with ICPM among older adults with TBI, yet utilization of ICPM remains low, especially among those meeting the BTF guidelines, and potential benefits remain unclear. This study highlights the need for better understanding of factors that influence compliance with BTF guidelines and the risks versus benefits of ICPM in this population.

LEVEL OF EVIDENCE

Prognostic and epidemiological, level III.

The historic evolution of intracranial pressure and cerebrospinal fluid pulse pressure concepts: Two centuries of challenges

BACKGROUND

There is a consensus on the importance of monitoring intracranial pressure (ICP) during neurosurgery, and this monitoring reduces mortality during procedures. Current knowledge of ICP and cerebrospinal fluid pulse pressure has been built thanks to more than two centuries of research on brain dynamics.

METHODS

Articles and books were selected using the descriptors "ICP," "cerebrospinal fluid pulse," "monitoring," "Monro-Kellie doctrine," and "ICP waveform" in electronic databases PubMed, Lilacs, Science Direct, and EMBASE.

RESULTS

Several anatomists and physiologists have helped clarify the patterns of intracranial volumes under normal and pathological conditions. Monro-Kellie doctrine was an important step in a story that is reconstructed in this article. Through documentary research, we report the contribution of important medical figures, such as Monro, Kellie, Abercrombie, Burrows, Cushing, Langfitt, Marmarou, and other physiologists and anatomists who left their marks on the history of Medicine.

CONCLUSION

Understanding intracranial dynamics is an unfinished historical construction. Current knowledge is the result of two centuries of research that began with the investigations of Alexander Monro secundus.

Evaluation of transpalpebral ultrasonographic measurement of optic nerve sheath diameter for indirect assessment of intracranial pressure in anesthetized and standing healthy adult horses

OBJECTIVE

To determine whether an association exists between direct intracranial pressure (ICP) measurement and ultrasonographic measurement of optic nerve sheath diameter (ONSD) in anesthetized and standing horses.

DESIGN

Cross-sectional study performed on a convenience sample of healthy adult horses.

SETTING

University teaching hospital.

ANIMALS

Eight adult horses donated to the University. Enrolled horses were free of abnormalities on physical examination, CBC, neurological evaluation, and ophthalmological examination.

MEASUREMENTS AND MAIN RESULTS

Horses were anesthetized in lateral recumbency for placement of an ICP transducer. Three head positions (neutral, elevated, and lowered) were used to alter ICP. ICP and ONSD in 2 directions (D1 and D2) were recorded at 5 and 10 minutes after position change to elevated and lowered. ICP and ONSD measurements were repeated in standing sedated horses 24-36 hours after recovery from anesthesia. Linear regressions were performed with ICP as the dependent variable and ONSD as the independent variable by head position and times. Linear regressions were also performed for change from neutral under anesthesia, with ONSD as the independent variable and ICP as the dependent variable, by head position and times. Significance was set at P < 0.05. There was a moderate association between ICP and ONSD in horses with head lowered at 5 and 10 minutes (R² values = 63%-78%) and weak association in head elevated at 10 minutes (R² values = 56%-63%). There was a weak association between change from neutral ICP and change from neutral ONSD in the elevated anesthetized position at 10 minutes for summed D1 + D2 (R²  = 33%).

CONCLUSIONS

Consistent associations between direct ICP and ONSD in anesthetized or standing horses were not observed. This inconsistency limits the clinically utility of transpalpebral ultrasonographic ONSD measurement for ICP monitoring in horses.

Neurologic Assessment of the Neurocritical Care Patient

Sedation is a ubiquitous practice in ICUs and NCCUs. It has the benefit of reducing cerebral energy demands, but also precludes an accurate neurologic assessment. Because of this, sedation is intermittently stopped for the purposes of a neurologic assessment, which is termed a neurologic wake-up test (NWT). NWTs are considered to be the gold-standard in continued assessment of brain-injured patients under sedation. NWTs also produce an acute stress response that is accompanied by elevations in blood pressure, respiratory rate, heart rate, and ICP. Utilization of cerebral microdialysis and brain tissue oxygen monitoring in small cohorts of brain-injured patients suggests that this is not mirrored by alterations in cerebral metabolism, and seldom affects oxygenation. The hard contraindications for the NWT are preexisting intracranial hypertension, barbiturate treatment, status epilepticus, and hyperthermia. However, hemodynamic instability, sedative use for primary ICP control, and sedative use for severe agitation or respiratory distress are considered significant safety concerns. Despite ubiquitous recommendation, it is not clear if additional clinically relevant information is gleaned through its use, especially with the contemporaneous utilization of multimodality monitoring. Various monitoring modalities provide unique and pertinent information about neurologic function, however, their role in improving patient outcomes and guiding treatment plans has not been fully elucidated. There is a paucity of information pertaining to the optimal frequency of NWTs, and if it differs based on type of injury. Only one concrete recommendation was found in the literature, exemplifying the uncertainty surrounding its utility. The most common sedative used and recommended is propofol because of its rapid onset, short duration, and reduction of cerebral energy requirements. Dexmedetomidine may be employed to facilitate serial NWTs, and should always be used in the non-intubated patient or if propofol infusion syndrome (PRIS) develops. Midazolam is not recommended due to tissue accumulation and residual sedation confounding a reliable NWT. Thus, NWTs are well-tolerated in selected patients and remain recommended as the gold-standard for continued neuromonitoring. Predicated upon one expert panel, they should be performed at least one time per day. Propofol or dexmedetomidine are the main sedative choices, both enabling a rapid awakening and consistent NWT.

Hospital-level intracranial pressure monitoring utilization and functional outcome in severe traumatic brain injury: a post hoc analysis of prospective multicenter observational study

Background

Several observational studies have shown that hospital-level intracranial pressure (ICP) monitoring utilization varies considerably in patients with severe traumatic brain injury (TBI). However, the relationship between hospital-level ICP monitoring utilization and clinical functional outcomes is unknown. This study examined whether patients with severe TBI treated at hospitals with high ICP monitoring utilization have better functional outcomes.

Methods

A post hoc analysis of the data from a prospective multicenter cohort study in Japan was undertaken, and included severe TBI patients (Glasgow Come Scale score ≤ 8). The primary exposure was hospital-level ICP monitoring utilization. Patients treated at hospitals with more than 80% ICP monitoring utilization were assigned to a high group and the others to a low group. The primary endpoint was a favorable functional outcome at 6 months after injury, defined as a Glasgow Outcome Scale score of good recovery or moderate disability. We conducted multiple logistic regression analyses adjusted for potential confounders.

Results

Of the 427 included patients, 60 were assigned to the high group and 367 to the low group. Multiple logistic regression analysis revealed that patients in the high group had significantly better functional outcome (adjusted odds ratio [OR]: 2.36; 95% confidence interval [CI]: 1.17–4.76; p = 0.016). Multiple logistic regression analysis adjusted for additional confounders supported this result (adjusted OR: 2.30; 95% CI: 1.07–4.92; p = 0.033).

Conclusion

Treatment at hospitals with high ICP monitoring utilization for severe TBI patients could be associated with better functional outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-020-00825-7.

Role of Intraoperative ICP And CPP Measurement for Predicting Surgical Outcome in Severe Traumatic Brain Injury

Introduction Traumatic brain injury (TBI) is one of the leading causes of mortality and disability worldwide, and optimizing the management of these patients is a continuing challenge. Intraoperative intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were evaluated for use as prognostic indicators after surgery for severe TBI. Although ICP and CPP monitoring is standard postsurgery treatment for TBI, very few studies have reported the use of ICP and CPP values monitored during surgery.

Objectives The objectives of this study were to evaluate the use of intraoperative ICP and CPP values as prognostic indicators and as subjective guidelines for managing severe TBI.

Materials and Methods All patients with severe TBI who underwent surgical decompression and ICP monitoring intraoperatively were included in our study from 2017 to 2018. We measured ICP and CPP values after creation of the first burr hole, after hematoma evacuation, and after wound closure.

Results From the analysis of receiver-operated characteristic (ROC) curves, we observed that ICP initial (cutoff > 28 mm Hg) and CPP initial (cutoff < 44.5 mm Hg) are the best predictors of unfavorable outcomes. Favorable outcome (Glasgow outcome scale [GOS] 4 and 5) and unfavorable outcome (GOS 1–3) after 6 months were achieved in 64.1 and 35.8% of patients, respectively. There was significant difference between the ICP and CPP values which are measured after the first burrhole, after hematoma evacuation, and after scalp closure in both favorable and unfavorable outcomes. The highest positive Pearson’s correlation coefficient is found between GOS and ICP and CPP after first burr hole.

Conclusion Monitoring ICP and CPP during surgery improves management in patients with severe TBI and provides an early prognostic indicator in such patients.

Use of Intracranial Pressure Monitoring in Patients with Severe Traumatic Brain Injury

OBJECTIVE

The Brain Trauma Foundation (BTF) recommends intracranial pressure (ICP) monitoring for all salvageable patients with an abnormal computed tomography (CT) scan and a Glasgow Coma Scale <9. Studies have shown that compliance with this recommendation is low. We sought to obtain contemporary national rates of ICP monitor placement in patients with severe traumatic brain injury (TBI).

METHODS

Patients from the National Trauma Data Bank from 2013 to 2017 who met BTF criteria for ICP monitoring were included. Placement of an intraparenchymal ICP monitor or an external ventricular drain was queried. Binary logistic regression was used to determine factors that influenced the placement of an ICP monitor.

RESULTS

A total of 21,374 patients with severe TBI and an abnormal CT scan were included in the study. An ICP monitor was placed in 6543 patients (30.6%). ICP monitor placement increased modestly from 28.6% in 2013 to 32.8% in 2017. The pooled odds of ICP monitor placement between 2014 and 2017 were not different from 2013 (odds ratio, 1.04; 95% confidence interval, 0.99-1.09), but the adjusted odds of ICP monitor placement in 2017 were significantly greater (odds ratio, 1.18; 95% confidence interval, 1.06-1.30). Treatment at a teaching hospital, subdural hematoma, multiple intracranial abnormalities on CT, and greater Injury Severity Score were associated with ICP monitor placement, whereas older age was negatively associated with ICP monitor placement.

CONCLUSIONS

The rate of ICP monitoring in patients with severe TBI who meet BTF criteria is low and increased only slightly from 2013 to 2017.

Cerebral Edema in Traumatic Brain Injury: a Historical Framework for Current Therapy

PURPOSE OF REVIEW

The purposes of this narrative review are to (1) summarize a contemporary view of cerebral edema pathophysiology, (2) present a synopsis of current management strategies in the context of their historical roots (many of which date back multiple centuries), and (3) discuss contributions of key molecular pathways to overlapping edema endophenotypes. This may facilitate identification of important therapeutic targets.

RECENT FINDINGS

Cerebral edema and resultant intracranial hypertension are major contributors to morbidity and mortality following traumatic brain injury. Although Starling forces are physical drivers of edema based on differences in intravascular vs extracellular hydrostatic and oncotic pressures, the molecular pathophysiology underlying cerebral edema is complex and remains incompletely understood. Current management protocols are guided by intracranial pressure measurements, an imperfect proxy for cerebral edema. These include decompressive craniectomy, external ventricular drainage, hyperosmolar therapy, hypothermia, and sedation. Results of contemporary clinical trials assessing these treatments are summarized, with an emphasis on the gap between intermediate measures of edema and meaningful clinical outcomes. This is followed by a brief statement summarizing the most recent guidelines from the Brain Trauma Foundation (4th edition). While many molecular mechanisms and networks contributing to cerebral edema after TBI are still being elucidated, we highlight some promising molecular mechanism-based targets based on recent research including SUR1-TRPM4, NKCC1, AQP4, and AVP1.

SUMMARY

This review outlines the origins of our understanding of cerebral edema, chronicles the history behind many current treatment approaches, and discusses promising molecular mechanism-based targeted treatments.

EVENTS ASSOCIATED WITH THE OCCURRENCE OF INTRACRANIAL HYPERTENSION IN PEDIATRIC PATIENTS WITH SEVERE CRANIOENCEPHALIC TRAUMA AND MONITORING OF INTRACRANIAL PRESSURE

Objective:

To determine the events associated with the occurrence of intracranial hypertension (ICH) in pediatric patients with severe cranioencephalic trauma.

Methods:

This was a prospective cohort study of patients 18 years old and younger with cranioencephalic trauma, scores below nine on the Glasgow Coma Scale, and intracranial pressure monitoring. They were admitted between September, 2005 and March, 2014 into a Pediatric Intensive Care Unit. ICH was defined as an episode of intracranial pressure above 20 mmHg for more than five minutes that needed treatment.

Results:

A total of 198 children and adolescents were included in the study, of which 70.2% were males and there was a median age of nine years old. ICH occurred in 135 (68.2%) patients and maximum intracranial pressure was 36.3 mmHg, with a median of 34 mmHg. A total of 133 (97.8%) patients with ICH received sedation and analgesia for treatment of the condition, 108 (79.4%) received neuromuscular blockers, 7 (5.2%) had cerebrospinal fluid drainage, 105 (77.2%) received mannitol, 96 (70.6%) received hyperventilation, 64 (47.1%) received 3% saline solution, 20 (14.7%) received barbiturates, and 43 (31.9%) underwent a decompressive craniectomy. The events associated with the occurrence of ICH were tomographic findings at the time of admission of diffuse or hemispheric swelling (edema plus engorgement). The odds ratio for ICH in patients with Marshall III (diffuse swelling) tomography was 14 (95%CI 2.8–113; p<0.003), and for those with Marshall IV (hemispherical swelling) was 24.9 (95%CI 2.4–676, p<0.018). Mortality was 22.2%.

Conclusions:

Pediatric patients with severe cranioencephalic trauma and tomographic alterations of Marshall III and IV presented a high chance of developing ICH.

Evaluation of a New Catheter for Simultaneous Intracranial Pressure Monitoring and Cerebral Spinal Fluid Drainage: A Pilot Study

OBJECTIVES

Intracranial pressure (ICP) monitoring is a common practice when treating intracranial pathology with risk of elevated ICP. External ventricular drain (EVD) insertion is a standard approach for both monitoring ICP and draining cerebrospinal fluid (CSF). However, the conventional EVD cannot serve these two purposes simultaneously because it cannot accurately measure ICP and its pulsatile waveform while the EVD is open to CSF drainage. A new Integra^® Camino^® FLEX Ventricular Catheter (Integra Lifesciences, County Offaly, Ireland) with a double-lumen construction has been recently introduced into the market, and it can monitor ICP waveforms even during CSF drainage. The aim of this study was to evaluate and validate this new FLEX catheter for ICP monitoring in a neurological intensive care unit.

METHODS

Six patients with 34 EVD open/close episodes were retrospectively analyzed. Continuous ICP was detected in two ways: through the FLEX sensor at the tip (ICP_f) and through a fluid-coupled manometer within the FLEX catheter, functioning as a conventional EVD (ICP_e). The morphologies of ICP_f and ICP_e pulses were extracted using Morphological Clustering and Analysis of ICP algorithm, an algorithm that has been validated in previous publications. The mean ICP and waveform shapes of ICP pulses detected through the two systems were compared. Bland-Altman plots were used to assess the agreement of the two systems.

RESULTS

A significant linear relationship existed between mean ICP_f and mean ICP_e, which can be described as: mICP_f = 0.81 × mICP_e + 1.67 (r = 0.79). The Bland-Altman plot revealed that no significant difference existed between the two ICPs (average of [ICP_e-ICP_f] was - 1.69 mmHg, 95% limits of agreement: - 7.94 to 4.56 mmHg). The amplitudes of the landmarks of ICP pulse waveforms from the two systems showed strong, linear relationship (r ranging from 0.89 to 0.94).

CONCLUSIONS

This study compared a new FLEX ventricular catheter with conventional fluid-coupled manometer for ICP waveform monitoring. Strong concordance in ICP value and waveform morphology between the two systems indicates that this catheter can be used for reliability for both clinical and research applications.

Outcome and rational management of civilian gunshot injuries to the brain-retrospective analysis of patients treated at the Helsinki University Hospital from 2000 to 2012

Background

Treatment of gunshot wounds of the brain (GSWB) remains controversial and there is high variation in reported survival rates (from < 10 to > 90%) depending on the etiology and country. We retrospectively analyzed the outcome of a series of consecutive GSWB patients admitted alive to a level 1 trauma center in a safe high-income welfare country with a low rate of homicidal gun violence.

Methods

Patients admitted due to a GSWB to the HUS Helsinki University Hospital during 2000–2012 were identified from hospital discharge registry and log books of the emergency room and ICU. CT scans and medical records of these patients were reviewed. Univariate analysis and backward logistic regression were performed, and their results compared with that of a systematic literature review of factors related to the outcome of GSWB patients.

Results

Sixty-four patients admitted alive after GSWB were identified. Eighty percent had self-inflicted GSWB, 81% were contact shots, and 70% were caused by handguns. In-hospital mortality was 72%. Factors associated with mortality in our series were low GCS (≤ 8) at admission, transventricular bullet trajectory, and associated damage to deep brain structures, as reported before in the literature. Of the 64 patients admitted alive, 42% (27/64) were admitted to ICU, 34% (22/64) underwent surgery, and in 25% (16/64), craniotomy and hematoma evacuation was performed. Mortality in the surgically treated group was 32% but near 100% without surgery and ICU treatment. Median GOS in the surgically treated patients was 3 (range 1–5).

Conclusions

GSWB caused by contact shot from handguns has a high mortality rate, but can be survived with reasonable outcome if limited to lobar injury without significant damage to deep brain structures or brain stem. In such GSWB patients, initial aggressive resuscitation, ICU admission, and surgery seem indicated.

Electronic supplementary material

The online version of this article (10.1007/s00701-019-03952-y) contains supplementary material, which is available to authorized users.

Respect your elders: effects of ageing on intracranial pressure monitor use in traumatic brain injury

BACKGROUND

The Brain Trauma Foundation recommends intracranial pressure (ICP) monitor placement for patients with severe traumatic brain injury (TBI). Adherence with these guidelines in elderly patients is unknown. We hypothesized that disparities in ICP monitor placement would exist based on patient age.

METHODS

Using the National Trauma Data Bank (2010-2014), we identified patients admitted for blunt TBI with admission Glasgow Coma Scale (GCS) scores of 3-8. Patients were excluded if they had a non-Head Abbreviated Injury Scale (AIS) score ≥3, hospital length of stay <24 hours or were discharged from the emergency department. Demographic data, ICP monitor placement, GCS, AIS-Head, Injury Severity Score, and outcome measures were collected. Propensity score matching between ICP monitor and non-ICP monitor patients was used for logistic regression and Cox multivariate regression analyses.

RESULTS

Of the 30 710 patients with blunt TBI with GCS scores of 3-8 included in our study, 4093 were treated with an ICP monitor. ICP monitor placement rates significantly decreased with increasing age. Multivariable analysis demonstrated that patients treated with an ICP monitor were more likely to be younger, male, have private/commercial insurance, and receive care at an institution with three or more neurosurgeons.

CONCLUSION

Patients ≥65 years of age with severe blunt TBI are less likely to be treated with an ICP monitor than younger patients. Age disparities in adherence to Brain Trauma Foundation guidelines may alter the outcomes for patients with severe TBI.

LEVEL OF EVIDENCE

Level IV.

Optic Nerve Sheath Diameter Correlation with Elevated Intracranial Pressure Determined via Ultrasound

Background

The early detection of elevated intracranial pressure (ICP) can not only prevent mortality but also aid in more aggressive management. Brain computed tomography (CT) is a mainstay modality in detecting elevated ICP, but the feasibility of using brain CTs to detect elevated ICP in critically ill patients is limited, especially for patients who require high levels of inotropic support. The optic nerve sheath is a direct extension of the brain meninges. Therefore, the elevation of ICP is directly transmitted to the sheath. Measuring the optic nerve sheath diameter (ONSD) through ultrasound (US) is a bedside, noninvasive means to detect elevated ICP. The goal of this study was to assess the correlation of ONSD with elevated ICP as measured via US in an intensive care unit (ICU).

Methods

We conducted a six-month prospective, single-center, observational study of mass effect stroke patients aged 18 to 65 years who had a traumatic brain injury (TBI) and were admitted to the ICU. Patients with chronic hydrocephalus, extensive local orbit trauma, a pre-existing ocular disease affecting the optic nerve and/or orbital cavity, hyperthyroidism with exophthalmos, and facial trauma affecting the orbits and/or eyeballs were excluded. We measured the ONSD at the entry of optic nerve into the globe using two-dimensional (2D) US.

Results

One hundred patients were included in the study. Forty-nine patients had diffuse cerebral edema detected on CT scan correlating with increased ONSD notable via bedside US. The mean ONSD related to CT-detectable elevated ICP was 0.61 cm. The sensitivity for the ONSD cut-off value of ≥5.8 mm was 94% (95% confidence interval [CI], 84.05% to 98.79%), and the specificity was 96.08% (95% CI, 86.7% to 99.52%).The positive predictive value was 92.08% (95% CI, 86.28% to 98.96%), and the negative predictive value was 94.23% (95% CI, 84.47% to 98.00%).

Conclusion

The greatest accuracy in ONSD was found with a cut-off of >0.58 cm in patients with positive CT brain findings. Therefore, US can be used as an initial screening test when physicians suspect a patient has elevated ICP.

Intracranial Pressure Monitoring in Experimental Traumatic Brain Injury: Implications for Clinical Management

Traumatic brain injury (TBI) is often associated with long-term disability and chronic neurological sequelae. One common contributor to unfavorable outcomes is secondary brain injury, which is potentially treatable and preventable through appropriate management of patients in the neurosurgical intensive care unit. Intracranial pressure (ICP) is currently the predominant neurological-specific physiological parameter used to direct the care of severe TBI (sTBI) patients. However, recent clinical evidence has called into question the association of ICP monitoring with improved clinical outcome. The detailed cellular and molecular derangements associated with intracranial hypertension (IC-HTN) and their relationship to injury phenotype and neurological outcomes are not completely understood. Various animal models of TBI have been developed, but the clinical applicability of ICP monitoring in the pre-clinical setting has not been well-characterized. Linking basic mechanistic studies in translational TBI models with investigation of ICP monitoring that more faithfully replicates the clinical setting will provide clinical investigators with a more informed understanding of the pathophysiology of IC-HTN, thus facilitating development of improved therapies for sTBI patients.

The effect of ICP monitoring in severe traumatic brain injury: a propensity score-weighted and adjusted regression approach

OBJECTIVE

The use of intracranial pressure (ICP) monitoring has been postulated to be beneficial in patients with severe traumatic brain injury (TBI), although studies investigating this hypothesis have reported conflicting results. The objective of this study was to evaluate the effect of inserting an ICP monitor on survival in patients with severe TBI.

METHODS

The Oslo University Hospital trauma registry was searched for the records of all patients admitted between January 1, 2002, and December 31, 2013, who fulfilled the Brain Trauma Foundation criteria for intracranial hypertension and who survived at least 24 hours after admission. The impact of ICP monitoring was investigated using both a logistic regression model and a multiple imputed, propensity score-weighted logistic regression analysis.

RESULTS

The study involved 1327 patients, in which 757 patients had an ICP monitor implanted. The use of ICP monitors significantly increased in the study period (p < 0.01). The 30-day overall mortality was 24.3% (322 patients), divided into 35.1% (200 patients, 95% confidence interval [CI] 31.3%-39.1%) in the group without an ICP monitor and 16.1% (122 patients, 95% CI 13.6%-18.9%) in the group with an ICP monitor. The impact of ICP monitors on 30-day mortality was found to be beneficial both in the complete case analysis logistic regression model (odds ratio [OR] 0.23, 95% CI 0.16-0.33) and in the adjusted, aggregated, propensity score-weighted imputed data sets (OR 0.22, 95% CI 0.15-0.35; both p < 0.001). The sensitivity analysis indicated that the findings are robust to unmeasured confounders.

CONCLUSIONS

The authors found that the use of an ICP monitor is significantly associated with improved survival in patients with severe head injury.

Patients Who Benefit from Intracranial Pressure Monitoring without Cerebrospinal Fluid Drainage After Severe Traumatic Brain Injury

BACKGROUND

India has a high traumatic brain injury (TBI) burden and intracranial pressure monitoring (ICP) remains controversial but some patients may benefit.

OBJECTIVE

To examine the association between ICP monitor placement and outcomes, and identify Indian patients with severe TBI who benefit from ICP monitoring

METHODS

We conducted a secondary analysis of a prospective cohort study at a level 1 Indian trauma center. Patients over 18 yr with severe TBI (admission Glasgow coma scale score < 8) who received tracheal intubation for at-least 48 h were examined. Propensity-based analysis using inverse probability weighting approach was used to examine ICP monitor placement within 72 h of admission and outcomes. Outcomes were in-hospital mortality and Glasgow Outcome Scale (GOS) score at discharge, 3, 6, and 12 mo. Death, vegetative, or major impairment defined unfavorable outcome.

RESULTS

The 200 patients averaged 36 [18 to 85] yr of age and average injury severity score of 31.4 [2 to 73]. ICP monitors were placed in 126 (63%) patients. Patients with ICP monitor placement experienced lower in-hospital mortality (adjusted relative risk [aRR]; 0.50 [0.29, 0.87]) than patients without ICP monitoring. However, there was no benefit at 3, 6, and 12 mo. With ICP monitor placement, absence of cerebral edema (aRR 0.54, 95% confidence interval 0.35-0.84), and absence of intraventricular hemorrhage (aRR 0.52, 95% confidence interval 0.33-0.82) were associated with reduced unfavorable outcomes.

CONCLUSION

ICP monitor placement without cerebrospinal fluid drainage within 72 h of admission was associated with reduced in-patient mortality. Patients with severe TBI but without cerebral edema and without intraventricular hemorrhage may benefit from ICP monitoring.

Intracranial pressure management in patients with traumatic brain injury: an update

PURPOSE OF REVIEW

Intracranial pressure (ICP) monitoring and treatment is central in the management of traumatic brain injury. Despite 4 decades of clinical use, several aspects remain controversial, including the indications for ICP and treatment options.

RECENT FINDINGS

Two major trials tested surgical decompression and mild hypothermia as treatments for high ICP. Both were rigorous, randomized, multicenter studies, with different designs. Decompression was tested for ICP refractory to conventional treatment, whereas hypothermia was offered as an alternative to conventional medical therapy. Decompression reduced mortality, but at the expense of more disability. The hypothermia trial was stopped because of a worse outcome in the treated arm. Indications for ICP monitoring have been reviewed and new international guidelines issued. New contributions published in 2016 have dealt with computerized analysis for predicting ICP crises; noninvasive or innovative methods for measuring ICP; reassessment of standard therapeutic interventions, such as hypertonic solutions and the level of intensity of ICP therapy.

SUMMARY

Aggressive strategies for ICP control, like surgical decompression or hypothermia, carefully tested, have controversial effects on outcome. Several articles have made worthwhile contributions to important clinical issues, but with no real breakthroughs.

Intracranial Pressure Monitoring-Review and Avenues for Development

Intracranial pressure (ICP) monitoring is a staple of neurocritical care. The most commonly used current methods of monitoring in the acute setting include fluid-based systems, implantable transducers and Doppler ultrasonography. It is well established that management of elevated ICP is critical for clinical outcomes. However, numerous studies show that current methods of ICP monitoring cannot reliably define the limit of the brain's intrinsic compensatory capacity to manage increases in pressure, which would allow for proactive ICP management. Current work in the field hopes to address this gap by harnessing live-streaming ICP pressure-wave data and a multimodal integration with other physiologic measures. Additionally, there is continued development of non-invasive ICP monitoring methods for use in specific clinical scenarios.

Head Computed Tomography Scan in Isolated Traumatic Brain Injury in a Low-Income Country

BACKGROUND

Head computed tomography scan (HCTS) is the cornerstone of the management of traumatic brain injury (TBI). The impact of performing a HCTS in TBI has been scarcely investigated in low-income countries (LICs). Furthermore, the cost of a HCTS is a burden for family finances.

METHODS

A prospective observational study was conducted in Burkina Faso. All consecutive patients with isolated TBI needing a HCTS were included. Result and impact of HCTS were evaluated.

RESULTS

There were 183 patients prescribed a HCTS for an isolated TBI. Mild, moderate, and severe TBIs represented 55%, 31%, and 14% of the cases, respectively. In 72 patients, HCTS was not performed because of economic barrier. Among the 110 HCTSs performed, there were intracranial lesions in 81 (74%) patients. Among the 110 performed HCTS, 34 (31% [22.3%-39.5%]) HCTSs altered the management of TBI, with 16 (15%) cases of surgical indications, and 20 (18%) cases of modification of the medical treatment. In patients without neurologic signs, the rate of alteration of management was 28%. The realization of the HCTSs was associated with the presence of neurologic signs and income level. In-hospital mortality was 11% (n = 21). Among the 162 patients discharged alive from the hospital, 27 (20%) were discharged with a severe disability state (Glasgow Outcome Scale score ≤3). The rate of return to work was 77%.

CONCLUSIONS

No modification of guidelines can be advocated from this study. However, given the financial burden on family of performing HCTS, research may identify criteria allowing for avoiding HCTS. Guidelines specific to LICs are needed to get closer to the best interest of patients.