Conventional neurocritical care and cerebral oxygenation after traumatic brain injury

Brain tissue oxygen combined with intracranial pressure monitoring versus isolated intracranial pressure monitoring in patients with traumatic brain injury: an updated systematic review and meta-analysis

Monitoring intracranial pressure (ICP) is pivotal in the management of severe traumatic brain injury (TBI), but secondary brain injuries can arise despite normal ICP levels. Cerebral tissue oxygenation monitoring (PbtO2) may detect neuronal tissue infarction thresholds, enhancing neuroprotection. We performed a systematic review and meta-analysis to evaluate the effects of combined cerebral tissue oxygenation (PbtO2) and ICP compared to isolated ICP monitoring in patients with TBI. PubMed, Embase, Cochrane, and Web of Sciences databases were searched for trials published up to June 2023. A total of 16 studies comprising 37,820 patients were included. ICP monitoring was universal, with additional placement of PbtO2 in 2222 individuals (5.8%). The meta-analysis revealed a reduction in mortality (OR 0.57, 95% CI 0.37-0.89, p = 0.01), a greater likelihood of favorable outcomes (OR 2.28, 95% CI 1.66-3.14, p < 0.01), and a lower chance of poor outcomes (OR 0.51, 95% CI 0.34-0.79, p < 0.01) at 6 months for the PbtO2 plus ICP group. However, these patients experienced a longer length of hospital stay (MD 2.35, 95% CI 0.50-4.20, p = 0.01). No significant difference was found in hospital mortality rates (OR 0.81, 95% CI 0.61-1.08, p = 0.16) or intensive care unit length of stay (MD 2.46, 95% CI - 0.11-5.04, p = 0.06). The integration of PbtO2 to ICP monitoring improved mortality outcomes and functional recovery at 6 months in patients with TBI. PROSPERO (International Prospective Register of Systematic Reviews) CRD42022383937; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=383937.

Extracranial pressure (ECP) monitoring in severe traumatic brain injury (TBI): A prospective study validating intra-abdominal pressure (IAP) measurement for predicting intracranial pressure (ICP)

Background

Intracranial pressure (ICP)--guided therapy is the standard of care in the management of severe traumatic brain injury (TBI). Ideal ICP monitoring technique is not yet available, based on its risks associated with bleeding, infection, or its unavailability at major centers. Authors propose that ICP can be gauged based on measuring pressures of other anatomical cavities, for example, the abdominal cavity. Researchers explored the possibility of monitoring intra-abdominal pressure (IAP) to predict ICP in severe TBI patients.

Methods

We measured ICP and IAP in severe TBI patients. ICP was measured using standard right frontal external ventricular drain (EVD) insertion and connecting it to the transducer. IAP was measured using a well-established technique of vesical pressure measurement through a manometer.

Results

A total of 28 patients (n = 28) with an age range of 18-65 years (mean of 32.36 years ± 13.52 years [Standard deviation]) and the median age of 28.00 years with an interquartile range (21.00-42.00 years) were recruited in this prospective study. About 57.1% (n = 16) of these patients were in the age range of 18-30 years. About 92.9% (n = 26) of the patients were male. The most common mode of injury (78.6%) was road traffic accidents (n = 22) and the mean Glasgow Coma Scale at presentation was 4.04 (range 3-9). The mean ICP measured at the presentation of this patient cohort was 20.04 mmHg. This mean ICP (mmHg) decreased from a maximum of 20.04 at the 0 h' time point (at the time of insertion of EVD) to a minimum of 12.09 at the 96 hr time point. This change in mean ICP (from 0 h to 96 h) was found to be statistically significant (Friedman Test: χ2 = 87.6, P ≤ 0.001). The mean IAP (cmH2O) decreased from a maximum of 16.71 at the 0 h' time point to a minimum of 9.68 at the 96 h' time point. This change was statistically significant (Friedman Test: χ2 = 71.8, P ≤ 0.001). The per unit percentage change in IAP on per unit percentage change in ICP we observed was correlated to each other. The correlation coefficient between these variables varied from 0.71 to 0.89 at different time frames. It followed a trend in a directly proportional manner and was found to be statistically significant (P < 0.001) in each time frame of the study. The rise in one parameter followed the rise in another parameter and vice versa.

Conclusion

In this study, we established that the ICP of severe TBI patients correlates well with IAP at presentation. This correlation was strong and constant, irrespective of the timeframe during the treatment and monitoring. This study also established that draining cerebrospinal fluid to decrease ICP in severe TBI patients is reflected in IAP. The study validates that IAP is a strong proxy of ICP in severe TBI patients.

Future of neurocritical care: Integrating neurophysics, multimodal monitoring, and machine learning

Multimodal monitoring (MMM) in the intensive care unit (ICU) has become increasingly sophisticated with the integration of neurophysical principles. However, the challenge remains to select and interpret the most appropriate combination of neuromonitoring modalities to optimize patient outcomes. This manuscript reviewed current neuromonitoring tools, focusing on intracranial pressure, cerebral electrical activity, metabolism, and invasive and noninvasive autoregulation monitoring. In addition, the integration of advanced machine learning and data science tools within the ICU were discussed. Invasive monitoring includes analysis of intracranial pressure waveforms, jugular venous oximetry, monitoring of brain tissue oxygenation, thermal diffusion flowmetry, electrocorticography, depth electroencephalography, and cerebral microdialysis. Noninvasive measures include transcranial Doppler, tympanic membrane displacement, near-infrared spectroscopy, optic nerve sheath diameter, positron emission tomography, and systemic hemodynamic monitoring including heart rate variability analysis. The neurophysical basis and clinical relevance of each method within the ICU setting were examined. Machine learning algorithms have shown promise by helping to analyze and interpret data in real time from continuous MMM tools, helping clinicians make more accurate and timely decisions. These algorithms can integrate diverse data streams to generate predictive models for patient outcomes and optimize treatment strategies. MMM, grounded in neurophysics, offers a more nuanced understanding of cerebral physiology and disease in the ICU. Although each modality has its strengths and limitations, its integrated use, especially in combination with machine learning algorithms, can offer invaluable information for individualized patient care.

Targeted temperature management and PbtO2 in traumatic brain injury

Introduction

Targeted Temperature Management (TTM) to normothermia is widely used in traumatic brain injury (TBI). We investigated the effects to of TTM to normothermia patients with TBI (GCS≤12) monitored with multimodality monitoring, to better understand the physiological consequences of this intervention.

Research question

In TBI patients cooled to normothermia and in which brain oxygenation deteriorates, are there changes in physiological parameters which are pertinent to brain oxygenation?

Material and method

102 TBI patients with continuous recordings of intracranial pressure (ICP) and brain oxygen tension (PbtO2) were studied retrospectively. Non-continuous arterial carbon dioxide (PaCO2) and oxygen (PaO2) tensions, and core body temperature (Tc) were added. PaO2 and PaCO2 were also corrected for Tc. Transitions from elevated Tc to normothermia were identified in 39 patients. The 8 h pre and post the transition to normothermia were compared. Data is given as median [IQR] or mean (SD).

Results

Overall, normothermia reduced ICP (12 [9-18] -11 [8-17] mmHg, p < 0.009) and Tcore (38.3 [0.3]-36.9 [0.4] oC, p < 0.001), but not PbtO2 (23.3 [16.6]-24.4 [17.2-28.7] mmHg, NS). Normothermia was associated with a fall in PbtO2 in 18 patients (24.5 [9.3] -20.8 [7.6] mmHg). Only in those with a fall in PbtO2 with cooling did ICP (15 [10.8-18.5] -12 [7.8-17.3] mmHg, p = 0.002), and temperature corrected PaCO2 (5.3 [0.5]- 4.9 [0.8] kPa, p = 0.001) decrease.

Discussion and conclusion

A reduction in PbtO2 was only present in the subgroup of patients with a fall in temperature corrected PaCO2 with cooling. This suggests that even modest temperature changes could result in occult hyperventilation in some patients. pH stat correction of ventilation may be an important factor to consider in future TTM protocols.

A Systematic Review on Traumatic Brain Injury Pathophysiology and Role of Herbal Medicines in its Management

BACKGROUND

Traumatic brain injury (TBI) is a worldwide problem. Almost about sixtynine million people sustain TBI each year all over the world. Repetitive TBI linked with increased risk of neurodegenerative disorder such as Parkinson, Alzheimer, traumatic encephalopathy. TBI is characterized by primary and secondary injury and exerts a severe impact on cognitive, behavioral, psychological and other health problem. There were various proposed mechanism to understand complex pathophysiology of TBI but still there is a need to explore more about TBI pathophysiology. There are drugs present for the treatment of TBI in the market but there is still need of more drugs to develop for better and effective treatment of TBI, because no single drug is available which reduces the further progression of this injury.

OBJECTIVE

The main aim and objective of structuring this manuscript is to design, develop and gather detailed data regarding about the pathophysiology of TBI and role of medicinal plants in its treatment.

METHOD

This study is a systematic review conducted between January 1995 to June 2021 in which a consultation of scientific articles from indexed periodicals was carried out in Science Direct, United States National Library of Medicine (Pubmed), Google Scholar, Elsvier, Springer and Bentham.

RESULTS

A total of 54 studies were analyzed, on the basis of literature survey in the research area of TBI.

CONCLUSION

Recent studies have shown the potential of medicinal plants and their chemical constituents against TBI therefore, this review targets the detailed information about the pathophysiology of TBI and role of medicinal plants in its treatment.

The Impact of Invasive Brain Oxygen Pressure Guided Therapy on the Outcome of Patients with Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Traumatic brain injury (TBI) is a major public health burden, causing death and disability worldwide. Intracranial hypertension and brain hypoxia are the main mechanisms of secondary brain injury. As such, management strategies guided by intracranial pressure (ICP) and brain oxygen (PbtO₂) monitoring could improve the prognosis of these patients. Our objective was to summarize the current evidence regarding the impact of PbtO₂-guided therapy on the outcome of patients with TBI. We performed a systematic search of PubMed, Scopus, and the Cochrane library databases, following the protocol registered in PROSPERO. Only studies comparing PbtO₂/ICP-guided therapy with ICP-guided therapy were selected. Primary outcome was neurological outcome at 3 and 6 months assessed by using the Glasgow Outcome Scale; secondary outcomes included hospital and long-term mortality, burden of intracranial hypertension, and brain tissue hypoxia. Out of 6254 retrieved studies, 15 studies (n = 37,245 patients, of who 2184 received PbtO₂-guided therapy) were included in the final analysis. When compared with ICP-guided therapy, the use of combined PbO₂/ICP-guided therapy was associated with a higher probability of favorable neurological outcome (odds ratio 2.21 [95% confidence interval 1.72-2.84]) and of hospital survival (odds ratio 1.15 [95% confidence interval 1.04-1.28]). The heterogeneity (I²) of the studies in each analysis was below 40%. However, the quality of evidence was overall low to moderate. In this meta-analysis, PbtO₂-guided therapy was associated with reduced mortality and more favorable neurological outcome in patients with TBI. The low-quality evidence underlines the need for the results from ongoing phase III randomized trials.

Role of brain tissue oxygenation (PbtO2) in the management of subarachnoid haemorrhage: a scoping review protocol

INTRODUCTION

In patients with subarachnoid haemorrhage (SAH), the initial brain oedema and increased blood volume can cause an increase in intracranial pressure (ICP) leading to impaired cerebral perfusion and tissue hypoxia. However, ICP monitoring may not be enough to detect tissue hypoxia, which can also occur in the absence of elevated ICP. Moreover, some patients will experience tissue hypoxia in a later phase after admission due to the occurrence of delayed cerebral ischaemia. Therefore, the measurement of brain oxygenation using invasive techniques has become of great interest. This scoping review seeks to examine the role of brain tissue oxygenation in the management of patients with SAH, mapping the existing literature to identify areas for future research.

METHODS AND ANALYSIS

This scoping review has been planned following the Joanna Briggs Institute recommendations and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The literature search will be performed using several databases: Medline, EMBASE, the Cochrane Central Register of Controlled Trials and Grey literature. The database searches are planned from the inception to May 2020. Two reviewers will independently screen titles and abstracts, followed by full-text screening of potentially relevant articles with a standardised data extraction. Articles eligible for the inclusion will be discussed with a third reviewer.

ETHICS AND DISSEMINATION

This paper does not require ethics approval. The results of our evaluation will be disseminated on author's web sites. Additional dissemination will occur through presentations at conferences, such as courses and science education conferences, regionally and nationally, and through articles published in peer-reviewed journals.

SCOPING REVIEW REGISTRATION

Open Science Framework Registration: https://doi.org/10.17605/OSF.IO/ZYJ7R.Trial registration numberClinicalTrials.gov Identifier: NCT03754114.

Evaluation of a New Multiparameter Brain Probe for Simultaneous Measurement of Brain Tissue Oxygenation, Cerebral Blood Flow, Intracranial Pressure, and Brain Temperature in a Porcine Model

BACKGROUND

A novel multiparameter brain sensor (MPBS) allows the simultaneous measurement of brain tissue oxygenation (ptiO₂), cerebral blood flow (CBF), intracranial pressure (ICP), and brain temperature with a single catheter. This laboratory investigation evaluates the MPBS in an animal model in relation to established reference probes.

METHODS

The study group consisted of 17 juvenile male pigs. Four MPBS and four reference probes were implanted per pig and compared simultaneously. The measured parameters were challenged by standardized provocations such as hyperoxia, dobutamine, and norepinephrine application, hypercapnia and hypoxia in combination with and without a controlled cortical impact (CCI) injury. Mean values over 2 min were collected for predefined time points and were analyzed using Bland-Altman plots.

RESULTS

The protocol was successfully conducted in 15 pigs of which seven received CCI. ICP and ptiO₂ were significantly influenced by the provocations. Subtraction of MPBS from reference values revealed a mean difference (limits of agreement) of 3.7 (- 20.5 to 27.9) mm Hg, - 2.9 (- 7.9 to 2.1) mm Hg, and 5.1 (- 134.7 to 145.0) % for ptiO₂, ICP, and relative CBF, respectively.

CONCLUSIONS

The MPBS is a promising measurement tool for multiparameter neuromonitoring. The conducted study demonstrates the in vivo functionality of the probe. Comparison with standard probes revealed a deviation which is mostly analogous to other multiparameter devices. However, further evaluation of the device is necessary before it can reliably be used for clinical decision making.

Intracranial pressure monitoring: Gold standard and recent innovations

Intracranial pressure monitoring (ICP) is based on the doctrine proposed by Monroe and Kellie centuries ago. With the advancement of technology and science, various invasive and non-invasive modalities of monitoring ICP continue to be developed. An ideal monitor to track ICP should be easy to use, accurate, reliable, reproducible, inexpensive and should not be associated with infection or haemorrhagic complications. Although the transducers connected to the extra ventricular drainage continue to be Gold Standard, its association with the likelihood of infection and haemorrhage have led to the search for alternate non-invasive methods of monitoring ICP. While Camino transducers, Strain gauge micro transducer based ICP monitoring devices and the Spiegelberg ICP monitor are the emerging technology in invasive ICP monitoring, optic nerve sheath diameter measurement, venous opthalmodynamometry, tympanic membrane displacement, tissue resonance analysis, tonometry, acoustoelasticity, distortion-product oto-acoustic emissions, trans cranial doppler, electro encephalogram, near infra-red spectroscopy, pupillometry, anterior fontanelle pressure monitoring, skull elasticity, jugular bulb monitoring, visual evoked response and radiological based assessment of ICP are the non-invasive methods which are assessed against the gold standard.

Treatment of severe traumatic brain injury in German pediatric intensive care units-a survey of current practice

PURPOSE

German pediatric guidelines for severe traumatic brain injury (TBI) management expired in 2011. Thus, divergent evidence-based institutional protocols are predominantly being followed. We performed a survey of current Pediatric Intensive Care Unit (PICU) management of isolated severe TBI in Germany to reveal potential varying practices.

METHODS

Seventy German PICUs were invited to join an anonymous online survey from February to May 2017. Twenty-nine participants (41.4%) successfully completed the survey (17 university hospitals and 12 district hospitals). The majority of items were polar (yes/no) or scaled (e.g., never - always). Main topics were imaging, neurosurgery, neuromonitoring, adjuvant therapy, and medication. Severity of TBI was defined via Glasgow Coma Scale.

RESULTS

The majority of respondents (93.1%) had internal TBI standards, and patients were mainly administered to interdisciplinary trauma units. The use of advanced neuromonitoring techniques, intracranial hypertension management, and drug treatment differed between PICUs. Routine administration of hypertonic saline in TBI-associated cerebral edema was performed by 3.4%, while it was never an option for 31.0% of the participants. Prophylactic anticonvulsive therapy was restrictively performed. If indicated, the main anticonvulsive drugs used were phenobarbital and levetiracetam. Neuroendocrine follow-up was recommended/performed by 58.6% of the PICUs.

CONCLUSIONS

This survey provides an overview of the current PICU practices of isolated severe TBI management in Germany and demonstrates a wide instrumental and therapeutical range, revealing an unmet need for the revised national guideline and further (international) clinical trials for the treatment of severe TBI in pediatrics.

Management of Pediatric Severe Traumatic Brain Injury: 2019 Consensus and Guidelines-Based Algorithm for First and Second Tier Therapies

OBJECTIVES

To produce a treatment algorithm for the ICU management of infants, children, and adolescents with severe traumatic brain injury.

DATA SOURCES

Studies included in the 2019 Guidelines for the Management of Pediatric Severe Traumatic Brain Injury (Glasgow Coma Scale score ≤ 8), consensus when evidence was insufficient to formulate a fully evidence-based approach, and selected protocols from included studies.

DATA SYNTHESIS

Baseline care germane to all pediatric patients with severe traumatic brain injury along with two tiers of therapy were formulated. An approach to emergent management of the crisis scenario of cerebral herniation was also included. The first tier of therapy focuses on three therapeutic targets, namely preventing and/or treating intracranial hypertension, optimizing cerebral perfusion pressure, and optimizing partial pressure of brain tissue oxygen (when monitored). The second tier of therapy focuses on decompressive craniectomy surgery, barbiturate infusion, late application of hypothermia, induced hyperventilation, and hyperosmolar therapies.

CONCLUSIONS

This article provides an algorithm of clinical practice for the bedside practitioner based on the available evidence, treatment protocols described in the articles included in the 2019 guidelines, and consensus that reflects a logical approach to mitigate intracranial hypertension, optimize cerebral perfusion, and improve outcomes in the setting of pediatric severe traumatic brain injury.

Pioglitazone Therapy and Fractures: Systematic Review and Meta- Analysis

INTRODUCTION

Thiazolidinediones are a group of synthetic medications used in type 2 diabetes treatment. Among available thiazolidinediones, pioglitazone is gaining increased attention due to its lower cardiovascular risk in type 2 diabetes mellitus sufferers and seems a promising future therapy. Accumulating evidence suggests that diabetic patients may exert bone fractures due to such treatments. Simultaneously, the female population is thought to be at greater risk. Still, the safety outcomes of pioglitazone treatment especially in terms of fractures are questionable and need to be clarified.

METHODS

We searched MEDLINE, Scopus, PsyInfo, eLIBRARY.ru electronic databases and clinical trial registries for studies reporting an association between pioglitazone and bone fractures in type 2 diabetes mellitus patients published before Feb 15, 2016. Among 1536 sources that were initially identified, six studies including 3172 patients proved relevant for further analysis.

RESULT

Pooled analysis of the included studies demonstrated that after treatment with pioglitazone patients with type 2 diabetes mellitus had no significant increase in fracture risk [odds ratio (OR): 1.18, 95% confidence interval (CI): 0.82 to 1.71, p=0.38] compared to other antidiabetic drugs or placebo. Additionally, no association was found between the risk of fractures and pioglitazone therapy duration. The gender of the patients involved was not relevant to the risk of fractures, too.

CONCLUSION

Pioglitazone treatment in diabetic patients does not increase the incidence of bone fractures. Moreover, there is no significant association between patients' fractures, their gender and the period of exposure to pioglitazone. Additional longitudinal studies need to be undertaken to obtain more detailed information on bone fragility and pioglitazone therapy.

Recommendations on RBC Transfusion in Critically Ill Children With Acute Brain Injury From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for RBC transfusions in critically ill children with acute brain injury developed by the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

The panel of 38 experts developed evidence-based, and when evidence was lacking, expert-based clinical recommendations as well as research priorities for RBC transfusions in critically ill children. The acute brain injury subgroup included three experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Transfusion and Anemia Expertise Initiative Consensus Conference experts developed and agreed upon two clinical and two research recommendations focused on RBC transfusion in the critically ill child with acute brain injury. Recommendations include consideration of RBC transfusion for a hemoglobin concentration between 7 and 10 g/dL in patients with acute brain injury and do not support the use of brain tissue PO2 monitoring to guide RBC transfusion decisions. Research is needed to better understand transfusion thresholds and brain tissue monitoring for pediatric patients with acute brain injury.

CONCLUSIONS

The Transfusion and Anemia Expertise Initiative Consensus Conference developed pediatric-specific clinical and research recommendations regarding RBC transfusion in the critically ill child with acute brain injury. Although agreement among experts was very strong, the available pediatric evidence was extremely limited with major gaps in the literature.

Neutrophils in traumatic brain injury (TBI): friend or foe?

Our knowledge of the pathophysiology about traumatic brain injury (TBI) is still limited. Neutrophils, as the most abundant leukocytes in circulation and the first-line transmigrated immune cells at the sites of injury, are highly involved in the initiation, development, and recovery of TBI. Nonetheless, our understanding about neutrophils in TBI is obsolete, and mounting evidences from recent studies have challenged the conventional views. This review summarizes what is known about the relationships between neutrophils and pathophysiology of TBI. In addition, discussions are made on the complex roles as well as the controversial views of neutrophils in TBI.

Delayed Hypoxemia after Traumatic Brain Injury Exacerbates Long-Term Behavioral Deficits

Hypoxemia during initial stabilization of patients with severe traumatic brain injury (TBI) has been associated with poorer outcomes. However, the effects of delayed hypoxemia occurring during intensive care post-TBI on outcome is unclear. Pre-clinical models of TBI have rarely shown cognitive or behavioral deficits beyond 6 weeks post-injury and commonly have not included modeling of secondary insults. We have previously developed a murine model of TBI followed by delayed hypoxemia to model the secondary insult of hypoxemia and brain hypoxia occurring in the intensive care setting. Understanding long-term effects of delayed hypoxemia post-TBI in our murine model is critical for future testing of candidate therapeutics targeting secondary brain hypoxia. For this study, forty 5-week-old male mice were randomized to controlled cortical impact (CCI; N = 24) or sham surgery (N = 16). One day later, awake animals were randomized to 60 min of hypoxemia or normoxemia. Six months after initial injury, animals underwent behavior testing (Morris water maze, social interaction, and tail suspension) before euthanasia for immunohistochemistry (IHC) assessments. At 6 months post-injury, mice experiencing CCI and hypoxemia (CCI+H) had longer swim distances to the hidden platform (51 cm) compared to CCI alone (26 cm) or sham animals (22 cm). During social interaction assessments, CCI + H mice spent less time interacting with novel stimulus mice (79 sec) than CCI alone (101 sec) or sham animals (139 sec). CCI + H had larger lesion volumes compared to CCI alone (14.0% vs. 9.9%; p < 0.003). Glial fibrillary acidic protein IHC at 6 months post-injury demonstrated increased astrogliosis in the ipsilateral white matter of CCI + H compared to CCI alone. To summarize, this clinically relevant model of delayed hypoxia post-TBI resulted in long-term behavioral deficits and evidence of exacerbated structural injury.

Multimodality neuromonitoring in severe pediatric traumatic brain injury

Each year, the annual hospitalization rates of traumatic brain injury (TBI) in children in the United States are 57.7 per 100K in the <5 years of age and 23.1 per 100K in the 5-14 years age group. Despite this, little is known about the pathophysiology of TBI in children and how to manage it most effectively. Historically, TBI management has been guided by clinical examination. This has been assisted progressively by clinical imaging, intracranial pressure (ICP) monitoring, and finally a software that can calculate optimal brain physiology. Multimodality monitoring affords clinicians an early indication of secondary insults to the recovering brain including raised ICP and decreased cerebral perfusion pressure. From variables such as ICP and arterial blood pressure, correlations can be drawn to determine parameters of cerebral autoregulation (pressure reactivity index) and "optimal cerebral perfusion pressure" at which the vasculature is most reactive. More recently, significant advances using both direct and near-infrared spectroscopy-derived brain oxygenation plus cerebral microdialysis to drive management have been described. Here in, we provide a perspective on the state-of-the-art techniques recently implemented in clinical practice for pediatric TBI.

Aggressive blood pressure treatment of hypertensive intracerebral hemorrhage may lead to global cerebral hypoperfusion: Case report and imaging perspective

Hypoperfusion injury related to blood pressure decrease in acute hypertensive intracerebral hemorrhage continues to be a controversial topic. Aggressive treatment is provided with the intent to stop the ongoing bleeding. However, there may be additional factors, including autoregulation and increased intracranial pressure, that may limit this approach. We present here a case of acute hypertensive intracerebral hemorrhage, in which aggressive blood pressure management to levels within the normal range led to global cerebral ischemia within multiple border zones. Global cerebral ischemia may be of concern in the management of hypertensive hemorrhage in the presence of premorbid poorly controlled blood pressure and increased intracranial pressure.

Hunt-Hess 5 subarachnoid haemorrhage presenting with cardiac arrest is associated with larger volume bleeds

AIMS

The mechanism, effects, and outcomes of cardiac arrest (CA) caused by subarachnoid haemorrhage (SAH) remain unclear. We compared SAH patients presenting with CA to other high-grade SAH patients presenting without CA in order to better understand (1) the cause of CA, (2) cerebral pathophysiology following CA, and (3) outcomes of CA in patients with SAH.

METHODS

We performed a retrospective analysis of a prospectively collected observational cohort. 31 Hunt-Hess 5 patients that presented with CA were compared to 146 Hunt-Hess 5 patients that presented without CA. Clinical and imaging findings were predefined and adjudicated. Cerebral physiology measures were available for a subset of patients, matched 1:1 by age.

RESULTS

Twenty-two (71%) CA patients had pulseless electrical activity/asystole compared to 2 (6%) with a shockable rhythm. The CA patients were younger (OR 0.96, 95% CI 0.93-0.99, p=0.009), had more SAH on CT (OR 1.07, 95% CI 1.01-1.13, p=0.02), and had higher in-hospital mortality (87% vs. 58%, OR 6.2 (2.1-26.6), p=0.004). There were no differences in aneurysm location, cerebral herniation, or ictal seizures. Despite similar cerebral perfusion pressure, CA patients had pathologically lower brain tissue oxygenation, lower glucose, and higher lactate to pyruvate ratios.

CONCLUSIONS

CA in SAH is associated with larger volume bleeds. Despite normal cerebral perfusion pressures, CA patients show compromised cerebral physiology.

Management of Traumatic Brain Injury

Traumatic brain injury remains a serious public health problem, causing death and disability for millions. In order to maximize outcomes in the face of a complex injury to a complex organ, a variety of advanced neuromonitoring techniques may be used to guide surgical and medical decision-making. Because of the heterogeneity of injury types and the plethora of treatment confounders present in this patient population, the scientific study of specific interventions is challenging. This challenge highlights the need for a firm understanding of the anatomy and pathophysiology of brain injuries when making clinical decisions in the intensive care unit.

Targeted treatment in severe traumatic brain injury in the age of precision medicine

In recent years, much progress has been made in our understanding of traumatic brain injury (TBI). Clinical outcomes have progressively improved, but evidence-based guidelines for how we manage patients remain surprisingly weak. The problem is that the many interventions and strategies that have been investigated in randomized controlled trials have all disappointed. These include many concepts that had become standard care in TBI. And that is just for adult TBI; in children, the situation is even worse. Not only is pediatric care more difficult than adult care because physiological norms change with age, but also there is less evidence for clinical practice. In this article, we discuss the heterogeneity inherent in TBI and why so many clinical trials have failed. We submit that a key goal for the future is to appreciate important clinical differences between patients in their pathophysiology and their responses to treatment. The challenge that faces us is how to rationally apply therapies based on the specific needs of an individual patient. In doing so, we may be able to apply the principles of precision medicine approaches to the patients we treat.

Rethinking Neuroprotection in Severe Traumatic Brain Injury: Toward Bedside Neuroprotection

Neuroprotection after traumatic brain injury (TBI) is an important goal pursued strenuously in the last 30 years. The acute cerebral injury triggers a cascade of biochemical events that may worsen the integrity, function, and connectivity of the brain cells and decrease the chance of functional recovery. A number of molecules acting against this deleterious cascade have been tested in the experimental setting, often with preliminary encouraging results. Unfortunately, clinical trials using those candidate neuroprotectants molecules have consistently produced disappointing results, highlighting the necessity of improving the research standards. Despite repeated failures in pharmacological neuroprotection, TBI treatment in neurointensive care units has achieved outcome improvement. It is likely that intensive treatment has contributed to this progress offering a different kind of neuroprotection, based on a careful prevention and limitations of intracranial and systemic threats. The natural course of acute brain damage, in fact, is often complicated by additional adverse events, like the development of intracranial hypertension, brain hypoxia, or hypoperfusion. All these events may lead to additional brain damage and worsen outcome. An approach designed for early identification and prompt correction of insults may, therefore, limit brain damage and improve results.

Oxygen availability and spreading depolarizations provide complementary prognostic information in neuromonitoring of aneurysmal subarachnoid hemorrhage patients

Multimodal neuromonitoring in neurocritical care increasingly includes electrocorticography to measure epileptic events and spreading depolarizations. Spreading depolarization causes spreading depression of activity (=isoelectricity) in electrically active tissue. If the depression is long-lasting, further spreading depolarizations occur in still isoelectric tissue where no activity can be suppressed. Such spreading depolarizations are termed isoelectric and are assumed to indicate energy compromise. However, experimental and clinical recordings suggest that long-lasting spreading depolarization-induced depression and isoelectric spreading depolarizations are often recorded outside of the actual ischemic zones, allowing the remote diagnosis of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage. Here, we analyzed simultaneous electrocorticography and tissue partial pressure of oxygen recording in 33 aneurysmal subarachnoid hemorrhage patients. Multiple regression showed that both peak total depression duration per recording day and mean baseline tissue partial pressure of oxygen were independent predictors of outcome. Moreover, tissue partial pressure of oxygen preceding spreading depolarization was similar and differences in tissue partial pressure of oxygen responses to spreading depolarization were only subtle between isoelectric spreading depolarizations and spreading depressions. This further supports that, similar to clustering of spreading depolarizations, long spreading depolarization-induced periods of isoelectricity are useful to detect energy compromise remotely, which is valuable because the exact location of future developing pathology is unknown at the time when the neurosurgeon implants recording devices.

Recording, analysis, and interpretation of spreading depolarizations in neurointensive care: Review and recommendations of the COSBID research group

Spreading depolarizations (SD) are waves of abrupt, near-complete breakdown of neuronal transmembrane ion gradients, are the largest possible pathophysiologic disruption of viable cerebral gray matter, and are a crucial mechanism of lesion development. Spreading depolarizations are increasingly recorded during multimodal neuromonitoring in neurocritical care as a causal biomarker providing a diagnostic summary measure of metabolic failure and excitotoxic injury. Focal ischemia causes spreading depolarization within minutes. Further spreading depolarizations arise for hours to days due to energy supply-demand mismatch in viable tissue. Spreading depolarizations exacerbate neuronal injury through prolonged ionic breakdown and spreading depolarization-related hypoperfusion (spreading ischemia). Local duration of the depolarization indicates local tissue energy status and risk of injury. Regional electrocorticographic monitoring affords even remote detection of injury because spreading depolarizations propagate widely from ischemic or metabolically stressed zones; characteristic patterns, including temporal clusters of spreading depolarizations and persistent depression of spontaneous cortical activity, can be recognized and quantified. Here, we describe the experimental basis for interpreting these patterns and illustrate their translation to human disease. We further provide consensus recommendations for electrocorticographic methods to record, classify, and score spreading depolarizations and associated spreading depressions. These methods offer distinct advantages over other neuromonitoring modalities and allow for future refinement through less invasive and more automated approaches.

Brain Multimodality Monitoring: Updated Perspectives

The challenges posed by acute brain injury (ABI) involve the management of the initial insult in addition to downstream inflammation, edema, and ischemia that can result in secondary brain injury (SBI). SBI is often subclinical, but can be detected through physiologic changes. These changes serve as a surrogate for tissue injury/cell death and are captured by parameters measured by various monitors that measure intracranial pressure (ICP), cerebral blood flow (CBF), brain tissue oxygenation (PbtO2), cerebral metabolism, and electrocortical activity. In the ideal setting, multimodality monitoring (MMM) integrates these neurological monitoring parameters with traditional hemodynamic monitoring and the physical exam, presenting the information needed to clinicians who can intervene before irreversible damage occurs. There are now consensus guidelines on the utilization of MMM, and there continue to be new advances and questions regarding its use. In this review, we examine these recommendations, recent evidence for MMM, and future directions for MMM.

Neuroprotective measures in children with traumatic brain injury

Traumatic brain injury (TBI) is a major cause of death and disability in children. Severe TBI is a leading cause of death and often leads to life changing disabilities in survivors. The modern management of severe TBI in children on intensive care unit focuses on preventing secondary brain injury to improve outcome. Standard neuroprotective measures are based on management of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) to optimize the cerebral blood flow and oxygenation, with the intention to avoid and minimise secondary brain injury. In this article, we review the current trends in management of severe TBI in children, detailing the general and specific measures followed to achieve the desired ICP and CPP goals. We discuss the often limited evidence for these therapeutic interventions in children, extrapolation of data from adults, and current recommendation from paediatric guidelines. We also review the recent advances in understanding the intracranial physiology and neuroprotective therapies, the current research focus on advanced and multi-modal neuromonitoring, and potential new therapeutic and prognostic targets.

Multimodal neuromonitoring for traumatic brain injury: A shift towards individualized therapy

Multimodal neuromonitoring in the management of traumatic brain injury (TBI) enables clinicians to make individualized management decisions to prevent secondary ischemic brain injury. Traditionally, neuromonitoring in TBI patients has consisted of a combination of clinical examination, neuroimaging and intracranial pressure monitoring. Unfortunately, each of these modalities has its limitations and although pragmatic, this simplistic approach has failed to demonstrate improved outcomes, likely owing to an inability to consider the underlying heterogeneity of various injury patterns. As neurocritical care has evolved, so has our understanding of underlying disease pathophysiology and patient specific considerations. Recent additions to the multimodal neuromonitoring platform include measures of cerebrovascular autoregulation, brain tissue oxygenation, microdialysis and continuous electroencephalography. The implementation of neurocritical care teams to manage patients with advanced brain injury has led to improved outcomes. Herein, we present a narrative review of the recent advances in multimodal neuromonitoring and highlight the utility of dedicated neurocritical care.

Pathophysiology and Management of Moderate and Severe Traumatic Brain Injury in Children

Traumatic brain injury remains a leading cause of morbidity and mortality in children. Key pathophysiologic processes of traumatic brain injury are initiated by mechanical forces at the time of trauma, followed by complex excitotoxic cascades associated with compromised cerebral autoregulation and progressive edema. Acute care focuses on avoiding secondary insults, including hypoxia, hypotension, and hyperthermia. Children with moderate or severe traumatic brain injury often require intensive monitoring and treatment of multiple parameters, including intracranial pressure, blood pressure, metabolism, and seizures, to minimize secondary brain injury. Child neurologists can play an important role in acute and long-term care. Acutely, as members of a multidisciplinary team in the intensive care unit, child neurologists monitor for early signs of neurological change, guide neuroprotective therapies, and transition patients to long-term recovery. In the longer term, neurologists are uniquely positioned to treat complications of moderate and severe traumatic brain injury, including epilepsy and cognitive and behavioral issues.

Early Changes in Brain Oxygen Tension May Predict Outcome Following Severe Traumatic Brain Injury

We report on the change in brain oxygen tension (PbtO2) over the first 24 h of monitoring in a series of 25 patients with severe traumatic brain injury (TBI) and relate this to outcome. The trend in PbtO2 for the whole group was to increase with time (mean PbtO2 17.4 [1.75] vs 24.7 [1.60] mmHg, first- vs last-hour data, respectively; p = 0.002). However, a significant increase in PbtO2 occurred in only 17 patients (68 %), all surviving to intensive care unit discharge (p = 0.006). Similarly, a consistent increase in PbtO2 with time occurred in only 13 patients, the correlation coefficient for PbtO2 versus time being ≥0.5 for all survivors. There were eight survivors and four non-survivors, with low correlation coefficients (<0.5). Significantly more patients with a correlation coefficient ≥0.5 for PbtO2 versus time survived in intensive care (p = 0.039). The cumulative length of time that PbtO2 was <20 mmHg was not significantly different among these three groups. In conclusion, although for the cohort as a whole PbtO2 increased over the first 24 h, the individual trends of PbtO2 were related to outcome. There was a significant association between improving PbtO2 and survival, despite these patients having cumulative durations of hypoxia similar to those of non-survivors.

Neuroprotection of hyperbaric oxygen therapy in sub-acute traumatic brain injury: not by immediately improving cerebral oxygen saturation and oxygen partial pressure

Although hyperbaric oxygen (HBO) therapy can promote the recovery of neural function in patients who have suffered traumatic brain injury (TBI), the underlying mechanism is unclear. We hypothesized that hyperbaric oxygen treatment plays a neuroprotective role in TBI by increasing regional transcranial oxygen saturation (rSO₂) and oxygen partial pressure (PaO₂). To test this idea, we compared two groups: a control group with 20 healthy people and a treatment group with 40 TBI patients. The 40 patients were given 100% oxygen of HBO for 90 minutes. Changes in rSO₂ were measured. The controls were also examined for rSO₂ and PaO₂, but received no treatment. rSO₂ levels in the patients did not differ significantly after treatment, but levels before and after treatment were significantly lower than those in the control group. PaO₂ levels were significantly decreased after the 30-minute HBO treatment. Our findings suggest that there is a disorder of oxygen metabolism in patients with sub-acute TBI. HBO does not immediately affect cerebral oxygen metabolism, and the underlying mechanism still needs to be studied in depth.

Intracranial pressure monitoring: fundamental considerations and rationale for monitoring

Traumatic brain injury (TBI) is a major cause of death and disability worldwide. In large part critical care for TBI is focused on the identification and management of secondary brain injury. This requires effective neuromonitoring that traditionally has centered on intracranial pressure (ICP). The purpose of this paper is to review the fundamental literature relative to the clinical application of ICP monitoring in TBI critical care and to provide recommendations on how the technique maybe applied to help patient management and enhance outcome. A PubMed search between 1980 and September 2013 identified 2,253 articles; 244 of which were reviewed in detail to prepare this report and the evidentiary tables. Several important concepts emerge from this review. ICP monitoring is safe and is best performed using a parenchymal monitor or ventricular catheter. While the indications for ICP monitoring are well established, there remains great variability in its use. Increased ICP, particularly the pattern of the increase and ICP refractory to treatment is associated with increased mortality. Class I evidence is lacking on how monitoring and management of ICP influences outcome. However, a large body of observational data suggests that ICP management has the potential to influence outcome, particularly when care is targeted and individualized and supplemented with data from other monitors including the clinical examination and imaging.

Safety and efficacy of combined epidural/general anesthesia during major abdominal surgery in patients with increased intracranial pressure: a cohort study

Background

The increased intracranial pressure can significantly complicate the perioperative period in major abdominal surgery, increasing the risk of complications, the length of recovery from the surgery, worsening the outcome. Epidural anesthesia has become a routine component of abdominal surgery, but its use in patients with increased intracranial pressure remains controversial. The goal of the study was to evaluate the safety and efficacy of epidural anesthesia, according to monitoring of intracranial pressure in patients with increased intracranial pressure.

Methods

The study includes 65 surgical patients who were routinely undergone the major abdominal surgery under combined epidural/general anesthesia. Depending on the initial ICP all patients were divided into 2 groups: 1 (N group) - patients with the normal intracranial pressure (≤12 mm Hg, n = 35) and 2 (E group) – patients with the elevated intracranial pressure (ICP > 12 mm Hg, n = 30). During the surgery we evaluated ICP, blood pressure, cerebral perfusion pressure (CPP). The parameters of recovery from anesthesia and the effectiveness of postoperative analgesia were also assessed.

Results

In N group ICP remained stable. In E group ICP decreased during anesthesia, the overall decline was 40 % at the end of the operation (from 15 to 9 mm Hg (P <0.05)). The correction of MAP with vasopressors to maintain normal CPP was required mainly in patients with increased ICP (70 % vs. 45 %, p <0.05). CPP declined by 19 % in N group. In E group the CPP reduction was 23 %, and then it remained stable at 60 mm Hg. No significant differences in time of the recovery of consciousness, effectiveness of postoperative analgesia and complications between patients with initially normal levels of ICP and patients with ICH were noted.

Conclusions

The combination of general and epidural anesthesia is safe and effective in patients with increased intracranial pressure undergoing elective abdominal surgery under the condition of maintaining the arterial pressure. Its use is not associated with the increase in intracranial pressure during the anesthesia, but it needs an intraoperative monitoring of ICP in order to prevent CPP reduction.

Intensive Care Treatment in Traumatic Brain Injury

Head injury remains a serious public problem, especially in the young population. The understanding of the mechanism of secondary injury and the development of appropriate monitoring and critical care treatment strategies reduced the mortality of head injury. The pathophysiology, monitoring and treatment principles of head injury are summarised in this article.

Multimodal monitoring in the pediatric intensive care unit: new modalities and informatics challenges

We review several newer modalities to monitor the brain in children with acute neurologic disease in the pediatric intensive care unit, such as partial brain tissue oxygen tension (PbtO2), jugular venous oxygen saturation (SjvO2), near infrared spectroscopy (NIRS), thermal diffusion measurement of cerebral blood flow, cerebral microdialysis, and EEG. We then discuss the informatics challenges to acquire, consolidate, analyze, and display the data. Acquisition includes multiple data types: discrete, waveform, and continuous. Consolidation requires device interoperability and time synchronization. Analysis could include pressure reactivity index and quantitative EEG. Displays should communicate the patient's current status, longitudinal and trend information, and critical alarms.

Monitoring of brain and systemic oxygenation in neurocritical care patients

Maintenance of adequate oxygenation is a mainstay of intensive care, however, recommendations on the safety, accuracy, and the potential clinical utility of invasive and non-invasive tools to monitor brain and systemic oxygenation in neurocritical care are lacking. A literature search was conducted for English language articles describing bedside brain and systemic oxygen monitoring in neurocritical care patients from 1980 to August 2013. Imaging techniques e.g., PET are not considered. A total of 281 studies were included, the majority described patients with traumatic brain injury (TBI). All tools for oxygen monitoring are safe. Parenchymal brain oxygen (PbtO2) monitoring is accurate to detect brain hypoxia, and it is recommended to titrate individual targets of cerebral perfusion pressure (CPP), ventilator parameters (PaCO2, PaO2), and transfusion, and to manage intracranial hypertension, in combination with ICP monitoring. SjvO2 is less accurate than PbtO2. Given limited data, NIRS is not recommended at present for adult patients who require neurocritical care. Systemic monitoring of oxygen (PaO2, SaO2, SpO2) and CO2 (PaCO2, end-tidal CO2) is recommended in patients who require neurocritical care.

Intracranial pressure after the BEST TRIP trial: a call for more monitoring

PURPOSE OF REVIEW

Increased intracranial pressure (ICP) is associated with worse outcome after traumatic brain injury (TBI), but whether its management improves the outcome is unclear. In this review, we will examine the implications of the Benchmark Evidence from South American Trials: Treatment of Intracranial Pressure (BEST TRIP) trial, evidence for an influence of ICP care on outcome, and a need for greater understanding of the pathophysiology than just ICP through multimodal monitoring (MMM) to enhance the outcome.

RECENT FINDINGS

The primary impact of the BEST TRIP trial, a randomized clinical trial that examined two TBI management strategies, one that used an ICP monitor, is in research and should not alter clinical practice. Analyses of large databases suggest TBI care based on the Brain Trauma Foundation guidelines and management of intracranial hypertension can improve patient outcome. However, accumulating evidence demonstrates there are several mechanisms of secondary brain injury (SBI), for example, microvascular dysfunction or alterations in glucose utilization that cannot be detected using an ICP monitor. In these patients, growing clinical evidence suggests that MMM can help manage SBI and improve TBI outcome.

SUMMARY

ICP-based monitoring and treatment alone may not be enough to enhance TBI outcome, but ICP and cerebral perfusion pressure therapy remain important in TBI care. Although high-quality evidence for MMM is limited, it should be more widely adapted to better understand the complex pathophysiology after TBI, better target care, and identify new therapeutic opportunities.

Physiological complexity of acute traumatic brain injury in patients treated with a brain oxygen protocol: utility of symbolic regression in predictive modeling of a dynamical system

Predictive modeling of emergent behavior, inherent to complex physiological systems, requires the analysis of large complex clinical data streams currently being generated in the intensive care unit. Brain tissue oxygen protocols have yielded outcome benefits in traumatic brain injury (TBI), but the critical physiological thresholds for low brain oxygen have not been established for a dynamical patho-physiological system. High frequency, multi-modal clinical data sets from 29 patients with severe TBI who underwent multi-modality neuro-clinical care monitoring and treatment with a brain oxygen protocol were analyzed. The inter-relationship between acute physiological parameters was determined using symbolic regression (SR) as the computational framework. The mean patient age was 44.4±15 with a mean admission GCS of 6.6±3.9. Sixty-three percent sustained motor vehicle accidents and the most common pathology was intra-cerebral hemorrhage (50%). Hospital discharge mortality was 21%, poor outcome occurred in 24% of patients, and good outcome occurred in 56% of patients. Criticality for low brain oxygen was intracranial pressure (ICP) ≥22.8 mm Hg, for mortality at ICP≥37.1 mm Hg. The upper therapeutic threshold for cerebral perfusion pressure (CPP) was 75 mm Hg. Eubaric hyperoxia significantly impacted partial pressure of oxygen in brain tissue (PbtO2) at all ICP levels. Optimal brain temperature (Tbr) was 34-35°C, with an adverse effect when Tbr≥38°C. Survivors clustered at [Formula: see text] Hg vs. non-survivors [Formula: see text] 18 mm Hg. There were two mortality clusters for ICP: High ICP/low PbtO2 and low ICP/low PbtO2. Survivors maintained PbtO2 at all ranges of mean arterial pressure in contrast to non-survivors. The final SR equation for cerebral oxygenation is: [Formula: see text]. The SR-model of acute TBI advances new physiological thresholds or boundary conditions for acute TBI management: PbtO2≥25 mmHg; ICP≤22 mmHg; CPP≈60-75 mmHg; and Tbr≈34-37°C. SR is congruous with the emerging field of complexity science in the modeling of dynamical physiological systems, especially during pathophysiological states. The SR model of TBI is generalizable to known physical laws. This increase in entropy reduces uncertainty and improves predictive capacity. SR is an appropriate computational framework to enable future smart monitoring devices.

Update on intensive neuromonitoring for patients with traumatic brain injury: a review of the literature and the current situation

Intracranial pressure (ICP) measurements are fundamental in the present protocols for intensive care of patients during the acute stage of severe traumatic brain injury. However, the latest report of a large scale randomized clinical trial indicated no association of ICP monitoring with any significant improvement in neurological outcome in severely head injured patients. Aggressive treatment of patients with therapeutic hypothermia during the acute stage of traumatic brain injury also failed to show any significant beneficial effects on clinical outcome. This lack of significant results in clinical trials has limited the therapeutic strategies available for treatment of severe traumatic brain injury. However, combined application of different types of neuromonitoring, including ICP measurement, may have potential benefits for understanding the pathophysiology of damaged brains. The combination of monitoring techniques is expected to increase the precision of the data and aid in prevention of secondary brain damage, as well as assist in determining appropriate time periods for therapeutic interventions. In this study, we have characterized the techniques used to monitor patients during the acute severe traumatic brain injury stage, in order to establish the beneficial effects on outcome observed in clinical studies conducted in the past and to follow up any valuable clues that point to additional strategies for aggressive management of these patients.

The impact of early flow and brain oxygen crisis on the outcome of patients with severe traumatic brain injury

BACKGROUND

Multimodality monitoring and goal-directed therapy may not prevent blood flow and brain oxygen (Flow/BrOx) crisis. We sought to determine the impact of these events on outcome in patients with severe traumatic brain injury (sTBI).

METHODS

Twenty-four patients with sTBI were treated to maintain intracranial pressure (ICP) less than or equal to 20 mm Hg, cerebral perfusion pressure (CPP) greater than or equal to 60 mm Hg, brain oxygen greater than or equal to 20 mm Hg, and near infrared spectroscopy greater than or equal to 60%. Flow/BrOx crisis events were recorded. The 14-day predicted mortality was compared with actual mortality.

RESULTS

Nonsurvivors had a significantly higher number of crisis events nonresponsive to treatment (P < .05). Mortality was 87.5% in patients with greater than or equal to 20 events versus 6.3% in patients with less than 20 events. The predicted mortality was 58%, whereas actual mortality was 33.3% (8/24), yielding a 42% reduction in mortality.

CONCLUSIONS

A multimodality monitoring and goal-directed therapy may decrease mortality in sTBI. However, Flow/BrOx crisis events still occur and predict a poor outcome.

Response of brain oxygen to therapy correlates with long-term outcome after subarachnoid hemorrhage

BACKGROUND

Brain oxygen (PbtO2) monitoring can help guide care of poor-grade aneurysmal subarachnoid hemorrhage (aSAH) patients. The relationship between PbtO2-directed therapy and long-term outcome is unclear. We hypothesized that responsiveness to PbtO2-directed interventions is associated with outcome.

METHODS

Seventy-six aSAH patients who underwent PbtO2 monitoring were included. Long-term outcome [Glasgow Outcome Score-Extended (GOS-E) and modified Rankin Scale (mRS)] was ascertained using the social security death database and structured telephone interviews. Univariate and multivariate regression were used to identify variables that correlated with outcome.

RESULTS

Data from 64 patients were analyzed (12 were lost to follow-up). There were 530 episodes of compromised PbtO2 (<20 mmHg) during a total of 7,174 h of monitor time treated with 1,052 interventions. Forty-two patients (66 %) survived to discharge. Median follow-up was 8.5 months (range 0.1-87). At most recent follow-up 35 (55 %) patients were alive, and 28 (44 %) had a favorable outcome (mRS ≤3). In multivariate ordinal regression analysis, only age and response to PbtO2-directed intervention correlated significantly with outcome. Increased age was associated with worse outcome (coeff. 0.8, 95 % CI 0.3-1.3, p = 0.003), and response to PbtO2-directed intervention was associated with improved outcome (coeff. -2.12, 95 % CI -4.0 to -0.26, p = 0.03). Patients with favorable outcomes had a 70 % mean rate of response to PbtO2-directed interventions whereas patients with poor outcomes had a 45 % response rate (p = 0.005).

CONCLUSIONS

Response to PbtO2-directed intervention is associated with improved long-term functional outcome in aSAH patients.