Ten good reasons to consider gastrointestinal function after acute brain injury

The brain-gut axis represents a bidirectional communication linking brain function with the gastrointestinal (GI) system. This interaction comprises a top-down communication from the brain to the gut, and a bottom-up communication from the gut to the brain, including neural, endocrine, immune, and humoral signaling. Acute brain injury (ABI) can lead to systemic complications including GI dysfunction. Techniques for monitoring GI function are currently few, neglected, and many under investigation. The use of ultrasound could provide a measure of gastric emptying, bowel peristalsis, bowel diameter, bowel wall thickness and tissue perfusion. Despite novel biomarkers represent a limitation in clinical practice, intra-abdominal pressure (IAP) is easy-to-use and measurable at bedside. Increased IAP can be both cause and consequence of GI dysfunction, and it can influence cerebral perfusion pressure and intracranial pressure via physiological mechanisms. Here, we address ten good reasons to consider GI function in patients with ABI, highlighting the importance of its assessment in neurocritical care.

Transcranial sonography in the critical patient

Transcranial ultrasonography is a non-invasive, bedside technique that has become a widely implemented tool in the evaluation and management of neurocritically ill patients. It constitutes a technique in continuous growth whose fundamentals (and limitations) must be known by the intensivist. This review provides a practical approach for the intensivist, including the different sonographic windows and planes of insonation and its role in different conditions of the neurocritical patients and in critical care patients of other etiologies.

Twelve controversial questions in aneurysmal subarachnoid hemorrhage

Critical care management of aneurysmal subarachnoid hemorrhage (aSAH) remains a major challenge. Despite the recent publication of guidelines from the American Heart Association/American Stroke Association and the Neurocritical Care Society, there are many controversial questions in the intensive care unit (ICU) management of this population. The authors provide an analysis of common issues in the ICU and provide guidance on the daily management of this specific population of neurocritical care patients.

Associated Risk Factors and Impact in Clinical Outcomes of Multiorgan Failure in Patients with TBI

BACKGROUND

Individual extracerebral organ dysfunction is common after severe traumatic brain injury (TBI) and impacts outcomes. However, multiorgan failure (MOF) has received less attention in patients with isolated TBI. Our objective was to analyze the risk factors associated with the development of MOF and its impact in clinical outcomes in patients with TBI.

METHODS

This was an observational, prospective, multicenter study using data from a nationwide registry that currently includes 52 intensive care units (ICUs) in Spain (RETRAUCI). Isolated significant TBI was defined as Abbreviated Injury Scale (AIS) ≥ 3 in the head area with no AIS ≥ 3 in any other anatomical area. Multiorgan failure was defined using the Sequential-related Organ Failure Assessment as the alteration of two or more organs with a score of ≥ 3. We analyzed the contribution of MOF to crude and adjusted mortality (age and AIS head) by using logistic regression analysis. A multiple logistic regression analysis was performed to analyze the risk factors associated with the development of MOF in patients with isolated TBI.

RESULTS

A total of 9790 patients with trauma were admitted to the participating ICUs. Of them, 2964 (30.2%) had AIS head ≥ 3 and no AIS ≥ 3 in any other anatomical area, and these patients constituted the study cohort. Mean age was 54.7 (19.5) years, 76% of patients were men, and ground-level falls were the main mechanism of injury (49.1%). In-hospital mortality was 22.2%. Up to 185 patients with TBI (6.2%) developed MOF during their ICU stay. Crude and adjusted (age and AIS head) mortality was higher in patients who developed MOF (odds ratio 6.28 [95% confidence interval 4.58-8.60] and odds ratio 5.20 [95% confidence interval 3.53-7.45]), respectively. The logistic regression analysis showed that age, hemodynamic instability, the need of packed red blood cells concentrates in the initial 24 h, the severity of brain injury, and the need for invasive neuromonitoring were significantly associated with MOF development.

CONCLUSIONS

MOF occurred in 6.2% of patients with TBI admitted to the ICU and was associated with increased mortality. MOF was associated with age, hemodynamic instability, the need of packed red blood cells concentrates in the initial 24 h, the severity of brain injury, and the need for invasive neuromonitoring.

External validation of the Glasgow Coma Scale-Pupils in patients with severe head injury

OBJECTIVES

To compare the ability of the Glasgow Coma Scale (GCS) score, the GCS Pupils (GCS-P) score, and the Pupil Reactivity Score (PRS) to predict mortality in patients with severe head injury.

MATERIAL AND METHODS

Retrospective analysis of all patients with severe head injury and initial GCS scores of 8 or lower on initial evaluation for whom records included pupil dilation information and clinical course after admission to intensive care units of participating hospitals. We assessed the ability of each of the 3 scores (GCS, GCS-P, and PRS) to predict mortality using discrimination analysis. Discrimination was estimated by calculating the areas under the receiver operating characteristic curves (AUC) and 95% CIs.

RESULTS

A total of 1551 patients with severe head injury and pupil dilation records were studied. The mean age was 50 years, 1190 (76.7%) were males, and 592 (38.2%) died. No pupil dilation was observed in 905 patients (58.3%), 362 (23.3%) had unilateral mydriasis, and 284 (18.3%) had bilateral mydriasis. The GCS-P score was significantly better at predicting mortality, with an AUC of 0.77 (95% CI, 0.74-0.79), versus 0.69 (95% CI, 0.67-0.72) for the GCS, and 0.75 (95% CI, 0.72-0.77) for the PRS. As the GCS-P score decreased, mortality increased.

CONCLUSION

The GCS-P was more useful than the GCS for predicting death after severe head injury.

Traumatic Brain Injury and Acute Kidney Injury-Outcomes and Associated Risk Factors

Our objective was to analyze the contribution of acute kidney injury (AKI) to the mortality of isolated TBI patients and its associated risk factors. Observational, prospective and multicenter registry (RETRAUCI) methods were used, from March 2015 to December 2019. Isolated TBI was defined as abbreviated injury scale (AIS) ≥ 3 head with no additional score ≥ 3. A comparison of groups was conducted using the Wilcoxon test, chi-square test or Fisher's exact test, as appropriate. A multiple logistic regression analysis was conducted to analyze associated risk factors in the development of AKI. For the result, overall, 2964 (30.2%) had AIS head ≥ 3 with no other area with AIS ≥ 3. The mean age was 54.7 (SD 19.5) years, 76% were men, and the ground-level falls was 49.1%. The mean ISS was 18.4 (SD 8). The in-hospital mortality was 22.2%. Up to 310 patients (10.6%) developed AKI, which was associated with increased mortality (39% vs. 17%, adjusted OR 2.2). Associated risk factors (odds ratio (OR) (95% confidence interval)) were age (OR 1.02 (1.01-1.02)), hemodynamic instability (OR 2.87 to OR 5.83 (1.79-13.1)), rhabdomyolysis (OR 2.94 (1.69-5.11)), trauma-associated coagulopathy (OR 1.67 (1.05-2.66)) and transfusion of packed red-blood-cell concentrates (OR 1.76 (1.12-2.76)). In conclusion, AKI occurred in 10.6% of isolated TBI patients and was associated with increased mortality.

Inflammatory Biomarkers of Traumatic Brain Injury

Traumatic brain injury (TBI) has a complex pathology in which the initial injury releases damage associated proteins that exacerbate the neuroinflammatory response during the chronic secondary injury period. One of the major pathological players in the inflammatory response after TBI is the inflammasome. Increased levels of inflammasome proteins during the acute phase after TBI are associated with worse functional outcomes. Previous studies reveal that the level of inflammasome proteins in biological fluids may be used as promising new biomarkers for the determination of TBI functional outcomes. In this study, we provide further evidence that inflammatory cytokines and inflammasome proteins in serum may be used to determine injury severity and predict pathological outcomes. In this study, we analyzed blood serum from TBI patients and respective controls utilizing Simple Plex inflammasome and V-PLEX inflammatory cytokine assays. We performed statistical analyses to determine which proteins were significantly elevated in TBI individuals. The receiver operating characteristics (ROC) were determined to obtain the area under the curve (AUC) to establish the potential fit as a biomarker. Potential biomarkers were then compared to documented patient Glasgow coma scale scores via a correlation matrix and a multivariate linear regression to determine how respective biomarkers are related to the injury severity and pathological outcome. Inflammasome proteins and inflammatory cytokines were elevated after TBI, and the apoptosis-associated speck like protein containing a caspase recruitment domain (ASC), interleukin (IL)-18, tumor necrosis factor (TNF)-α, IL-4 and IL-6 were the most reliable biomarkers. Additionally, levels of these proteins were correlated with known clinical indicators of pathological outcome, such as the Glasgow coma scale (GCS). Our results show that inflammatory cytokines and inflammasome proteins are promising biomarkers for determining pathological outcomes after TBI. Additionally, levels of biomarkers could potentially be utilized to determine a patient’s injury severity and subsequent pathological outcome. These findings show that inflammation-associated proteins in the blood are reliable biomarkers of injury severity that can also be used to assess the functional outcomes of TBI patients.

Risk Factors Associated with Mortality in Severe Chest Trauma Patients Admitted to the ICU

Our objective was to determine outcomes of severe chest trauma admitted to the ICU and the risk factors associated with mortality. An observational, prospective, and multicenter registry of trauma patients admitted to the participating ICUs (March 2015-December 2019) was utilized to collect the patient data that were analyzed. Severe chest trauma was defined as an Abbreviated Injury Scale (AIS) value of ≥3 in the thoracic area. Logistic regression analysis was used to evaluate the contribution of severe chest trauma to crude and adjusted ORs for mortality and to analyze the risk factors associated with mortality. Overall, 3821 patients (39%) presented severe chest trauma. The sample's characteristics were as follows: a mean age of 49.88 (19.21) years, male (77.6%), blunt trauma (93.9%), a mean ISS of 19.9 (11.6). Crude and adjusted (for age and ISS) ORs for mortality in severe chest trauma were 0.78 (0.68-0.89) and 0.43 (0.37-0.50) (p < 0.001), respectively. In-hospital mortality in the severe chest trauma patients without significant traumatic brain injury (TBI) was 5.63% and was 25.71% with associated significant TBI (p < 0.001). Age, the severity of injury (NISS and AIS-head), hemodynamic instability, prehospital intubation, acute kidney injury, and multiorgan failure were risk factors associated with mortality. The contribution of severe chest injury to the mortality of trauma patients admitted to the ICU was very low. Risk factors associated with mortality were identified.

Recommendations for the management of critically ill patients with COVID-19 in Intensive Care Units

The COVID-19 pandemic has led to the admission of a high number of patients to the ICU, generally due to severe respiratory failure. Since the appearance of the first cases of SARS-CoV-2 infection, at the end of 2019, in China, a huge number of treatment recommendations for this entity have been published, not always supported by sufficient scientific evidence or with methodological rigor necessary. Thanks to the efforts of different groups of researchers, we currently have the results of clinical trials, and other types of studies, of higher quality. We consider it necessary to create a document that includes recommendations that collect this evidence regarding the diagnosis and treatment of COVID-19, but also aspects that other guidelines have not considered and that we consider essential in the management of critical patients with COVID-19. For this, a drafting committee has been created, made up of members of the SEMICYUC Working Groups more directly related to different specific aspects of the management of these patients.

Development of a new score for early mortality prediction in trauma ICU patients: RETRASCORE

Background

Severity scores are commonly used for outcome adjustment and benchmarking of trauma care provided. No specific models performed only with critically ill patients are available. Our objective was to develop a new score for early mortality prediction in trauma ICU patients.

Methods

This is a retrospective study using the Spanish Trauma ICU registry (RETRAUCI) 2015–2019. Patients were divided and analysed into the derivation (2015–2017) and validation sets (2018–2019). We used as candidate variables to be associated with mortality those available in RETRAUCI that could be collected in the first 24 h after ICU admission. Using logistic regression methodology, a simple score (RETRASCORE) was created with points assigned to each selected variable. The performance of the model was carried out according to global measures, discrimination and calibration.

Results

The analysis included 9465 patients: derivation set 5976 and validation set 3489. Thirty-day mortality was 12.2%. The predicted probability of 30-day mortality was determined by the following equation: 1/(1 + exp (− y)), where y = 0.598 (Age 50–65) + 1.239 (Age 66–75) + 2.198 (Age > 75) + 0.349 (PRECOAG) + 0.336 (Pre-hospital intubation) + 0.662 (High-risk mechanism) + 0.950 (unilateral mydriasis) + 3.217 (bilateral mydriasis) + 0.841 (Glasgow ≤ 8) + 0.495 (MAIS-Head) − 0.271 (MAIS-Thorax) + 1.148 (Haemodynamic failure) + 0.708 (Respiratory failure) + 0.567 (Coagulopathy) + 0.580 (Mechanical ventilation) + 0.452 (Massive haemorrhage) − 5.432. The AUROC was 0.913 (0.903–0.923) in the derivation set and 0.929 (0.918–0.940) in the validation set.

Conclusions

The newly developed RETRASCORE is an early, easy-to-calculate and specific score to predict in-hospital mortality in trauma ICU patients. Although it has achieved adequate internal validation, it must be externally validated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03845-6.

Thyroid Disfunction in Critically Ill COVID-19 Patients. Relationship with In-Hospital Mortality

The incidence of thyroid disfunction has not been analyzed in critically ill COVID-19 patients. Our objective was to analyze the relationship of the thyroid profile and in-hospital mortality in critically ill COVID-19 patients. This was a prospective single-center study involving critically ill COVID-19 patients admitted to the ICU of a tertiary University Hospital. Thyroid hormones were measured through drawing blood samples from a central venous catheter at ICU admission and on the fifth day. A multiple logistic regression analysis was performed to analyze the variables associated with mortality. The ability of the different thyroid hormones to predict in-hospital mortality was evaluated by calculating the receiver operating characteristics (ROCs) and the area under the curve (AUC). A total of 78 patients were included in the study at ICU admission; 72 had their thyroid profile measured at day 5. In-hospital mortality reached 29.5%. Multiple logistic regression analysis showed that variables associated with mortality were age and prior beta-blocker therapy at ICU admission and age fT4 at day 5. The AUC for in-hospital mortality predictions of fT4 at day 5 was 0.69. Thyroid responses are commonly observed in critically ill COVID-19 patients. fT4 at day 5 after ICU admission was associated with mortality.

Factors associated with death due to trauma in patients with a Glasgow Coma Scale score of 3 and bilateral fixed dilated pupils

OBJECTIVES

To compare patients with a Glasgow Coma Scale (GCS) score of 3 stratified according to pupillary reaction and to explore factors associated with in-hospital death in those with bilateral fixed dilated pupils.

MATERIAL AND METHODS

Prospective, observational, multicenter study. We included all patients with trauma and GCS scores of 3 admitted to the intensive care unit from March 2015 to December 2019. Factors associated with in-hospital mortality in the patients with bilateral dilated pupils were explored using multiple regression analysis.

RESULTS

Of the 933 patients included, 454 (48.7%) had responsive pupils, 201 (21.5%) had a single fixed dilated pupil, and 278 (29.8%) had bilateral dilation. Hospital mortality was high in all 3 groups: 32.5% in those with normal responsive pupils, 54.6% in those with a single unreactive pupil, and 91.0% in those with bilateral dilation. Factors significantly associated with in-hospital death were age, a score of 3 or more on the Abbreviated Injury Scale for the head, and shock or refractory shock. Types I or II diffuse lesions and evacuated mass lesions were protective in patients with GCS scores of 3 and bilateral dilated pupils. Twelve of the 26 patients (46.1%) with bilateral dilated pupils and GCS scores of 3 had GCS scores of 14 or 15 on discharge from the hospital.

CONCLUSION

The in-hospital mortality was 91% in this study of trauma patients with GCS scores of 3 and bilateral dilated pupils. Factors significantly associated with in-hospital death were age, a score of 3 or more on the Abbreviated Injury Scale for the head, and shock or refractory shock. Types I or II diffuse lesions and evacuated mass lesions were protective in patients with GCS scores of 3 and bilateral dilated pupils.

[Recommendations for the management of critically ill patients with COVID-19 in Intensive Care Units]

La pandemia por COVID-19 ha provocado el ingreso de un elevado número de pacientes en UCI, generalmente por insuficiencia respiratoria severa. Desde la aparición de los primeros casos de infección por SARS-CoV-2, a finales de 2019, en China, se ha publicado una cantidad ingente de recomendaciones de tratamiento de esta entidad, no siempre respaldadas por evidencia científica suficiente ni con el rigor metodológico necesario. Gracias al esfuerzo de distintos grupos de investigadores, actualmente disponemos de resultados de ensayos clínicos, y otro tipo de estudios, de mayor calidad. Consideramos necesario realizar un documento que incluya recomendaciones que recojan estas evidencias en cuanto al diagnóstico y tratamiento de la COVID-19, pero también aspectos que otras guías no han contemplado y que consideramos fundamentales en el manejo del paciente crítico con COVID-19. Para ello se ha creado un comité redactor, conformado por miembros de los Grupos de Trabajo de SEMICYUC más directamente relacionados con diferentes aspectos específicos del manejo de estos pacientes.

Serum Caspase-1 as an Independent Prognostic Factor in Traumatic Brain Injured Patients

BACKGROUND

The objectives of this study were to assess the association between serum caspase 1 levels and known clinical and radiological prognostic factors and determine whether caspase 1was a more powerful predictor of outcome after traumatic brain injury (TBI) than clinical indices alone, to determine the association between the serum levels of caspase 1 and the 6-month outcome, and to evaluate if there is any association between caspase 1 with clinical and radiological variables.

METHODS

This prospective and observational study was conducted in a university hospital and included patients with TBI who required hospital admission. Serum samples were collected at hospital admission and 24 h after TBI. Caspase 1 levels were determined by enzyme-linked immunosorbent assay. Receiver operating characteristic curves were obtained to test the potential of caspase 1 to predict mortality (Glasgow Outcome Scale Extended score of 1) and unfavorable outcome (Glasgow Outcome Scale Extended scores of 1-4). Multivariate logistic regression was used to assess the effect of serum caspase 1 levels, adjusted by known clinical and radiological prognostic indices, on the outcome.

RESULTS

One hundred thirty-two patients and 33 healthy controls were included. We obtained 6-month outcome in 118 patients. On admission, the mean serum levels of caspase 1 were higher in patients with TBI compared with controls (157.9 vs. 108.5 pg/mL; p < 0.05) but not at 24 h after TBI. Serum caspase 1 levels on admission were higher in patients with unfavorable outcomes (189.5 vs. 144.1 pg/mL; p = 0.009). Similarly, serum caspase 1 levels on admission were higher in patients who died vs. patients who survived (213.6 vs. 146.8 pg/mL; p = 0.03). A logistic regression model showed that the serum caspase 1 level on admission was an independent predictor of 6-month unfavorable outcomes (odds ratio 1.05; 95% confidence interval 1-1.11; p = 0.05). Caspase 1 levels were higher in patients with severe TBI compared with those with moderate TBI, those with mild TBI, and healthy controls (p < 0.001). We did not find any correlation between caspase 1 and the radiological variables studied.

CONCLUSIONS

In this cohort of patients with TBI, we show that serum caspase 1 protein levels on admission are an independent prognostic factor after TBI. Serum caspase 1 levels on admission are higher in patients who will present unfavorable outcomes 6 months after TBI. Caspase 1 levels on admission are associated with the injury severity determined by the Glasgow Coma Scale.

Dexamethasone for the treatment of traumatic brain injured patients with brain contusions and pericontusional edema: Study protocol for a prospective, randomized and double blind trial

BACKGROUND

Traumatic brain injury (TBI) constitutes a leading cause of death and disability. Patients with TBI and cerebral contusions developing pericontusional edema are occasionally given dexamethasone on the belief that this edema is similar to that of tumors, in which the beneficial effect of dexamethasone has been demonstrated.

METHODS

The DEXCON TBI trial is a multicenter, pragmatic, randomized, triple-blind, placebo controlled trial to quantify the effects of dexamethasone on the prognosis of TBI patients with brain contusions and pericontusional edema. Adult patients who fulfill the elegibility criteria will be randomized to dexamethasone/placebo in a short and descending course: 4 mg/6 h (2 days); 4 mg/8 hours (2 days); 2 mg/6 hours (2 days); 2 mg/8 hours (2 days); 1 mg/8 hours (2 days); 1 mg/12 hours (2 days). The primary outcome is the Glasgow Scale Outcome Extended (GOSE) performed 1 month and 6 months after TBI. Secondary outcomes are: number of episodes of neurological deterioration; symptoms associated with TBI; adverse events; volume of pericontusional edema before and after 12 days of treatment; results of the neuropsychological tests one month and 6 months after TBI. The main analysis will be on an "intention-to-treat" basis. Logistic regression will estimate the effect of dexamethasone/placebo on GOSE at one month and at 6 months, dichotomized in unfavorable outcome (GOSE 1-6) and favorable outcome (GOSE 7-8). Efficacy will also be analyzed using the 'sliding dichotomy'. An interim and safety analysis will be performed including patients recruited during the first year to calculate the conditional power. A study with 600 patients would have 80% power (2 sided alpha = 5%) to detect a 12% absolute increase (from 50% to 62%) in good recovery.

DISCUSSION

This is a confirmative trial to elucidate the therapeutic efficacy of dexamethasone in a very specific group of TBI patients: patients with brain contusions and pericontusional edema. This trial could become an important milestone for TBI patients as nowadays there is no effective treatment in this type of patients.

TRIAL REGISTRATION

eudraCT: 2019-004038-41; Clinical Trials.gov: NCT04303065.

Machine learning techniques for mortality prediction in critical traumatic patients: anatomic and physiologic variables from the RETRAUCI study

Background

Interest in models for calculating the risk of death in traumatic patients admitted to ICUs remains high. These models use variables derived from the deviation of physiological parameters and/or the severity of anatomical lesions with respect to the affected body areas. Our objective is to create different predictive models of the mortality of critically traumatic patients using machine learning techniques.

Methods

We used 9625 records from the RETRAUCI database (National Trauma Registry of 52 Spanish ICUs in the period of 2015–2019). Hospital mortality was 12.6%. Data on demographic variables, affected anatomical areas and physiological repercussions were used. The Weka Platform was used, along with a ten-fold cross-validation for the construction of nine supervised algorithms: logistic regression binary (LR), neural network (NN), sequential minimal optimization (SMO), classification rules (JRip), classification trees (CT), Bayesian networks (BN), adaptive boosting (ADABOOST), bootstrap aggregating (BAGGING) and random forest (RFOREST). The performance of the models was evaluated by accuracy, specificity, precision, recall, F-measure, and AUC.

Results

In all algorithms, the most important factors are those associated with traumatic brain injury (TBI) and organic failures. The LR finds thorax and limb injuries as independent protective factors of mortality. The CT generates 24 decision rules and uses those related to TBI as the first variables (range 2.0–81.6%). The JRip detects the eight rules with the highest risk of mortality (65.0–94.1%). The NN model uses a hidden layer of ten nodes, which requires 200 weights for its interpretation. The BN find the relationships between the different factors that identify different patient profiles. Models with the ensemble methodology (ADABOOST, BAGGING and RandomForest) do not have greater performance. All models obtain high values ​​in accuracy, specificity, and AUC, but obtain lower values ​​in recall. The greatest precision is achieved by the SMO model, and the BN obtains the best recall, F-measure, and AUC.

Conclusion

Machine learning techniques are useful for creating mortality classification models in critically traumatic patients. With clinical interpretation, the algorithms establish different patient profiles according to the relationship between the variables used, determine groups of patients with different evolutions, and alert clinicians to the presence of rules that indicate the greatest severity.

Use of diffusion tensor imaging to assess the vasogenic edema in traumatic pericontusional tissue

BACKGROUND AND OBJECTIVE

Cerebral edema is a frequent and serious complication of traumatic brain injury (TBI). Diffusion tensor imaging (DTI) is considered a useful technique to assess white matter integrity after TBI. The objective of this prospective, observational study was to assess the characteristics of the vasogenic edema in the traumatic pericontusional tissue and compare it to the vasogenic edema found in brain tumors. We also included a control group.

METHODS

Using DTI, the Apparent diffusion coefficient (ADC) and Fractional anisotropy (FA) were measured in the area of vasogenic edema in both TBI and tumor patients. The measurements in the control group were done in the gray and white matter. We included 15 TBI patients, 18 tumor patients and 15 controls.

RESULTS

ADC and FA showed no differences between TBI and tumor patients (p=0.27 for AF; p=0.79 for ADC). Compared to healthy controls, TBI and tumor patients presented higher ADC values and lower FA values. The differences between TBI and controls were statistically significant (p<0.05).

CONCLUSIONS

In this prospective observational study using DTI-MRI in a selected group of mild and moderate TBI patients with vasogenic pericontusional edema we have shown that there were no significant differences of the ADC and FA values compared to brain tumor patients. Furthermore, healthy controls showed significant lower ADC values and higher FA values compared to TBI and tumor patients. Future studies, using DTI-MRI, should address whether any therapy has a favorable impact on the vasogenic edema of TBI patients with brain contusions.

Levels of caspase-1 in cerebrospinal fluid of patients with traumatic brain injury: correlation with intracranial pressure and outcome

OBJECTIVE

The objectives of this study were to evaluate levels of inflammasome-signaling proteins in serum and CSF of patients with traumatic brain injury (TBI), and to correlate these protein levels with intracranial pressure (ICP) and clinical outcomes at 6 months after injury.

METHODS

This is a prospective and observational study in patients with moderate and severe TBI who required an external ventricular drain as part of their treatment. Serum and CSF samples were collected 3 times a day for the first 5 days after TBI. The authors have determined the protein concentration of caspase-1 in the CSF and serum of patients with TBI by using commercially available enzyme-linked immunosorbent assays. The ICP value was recorded hourly. The 6-month outcome was assessed using the Glasgow Outcome Scale-Extended.

RESULTS

A total of 21 patients were included in this study, and a total of 234 paired serum-CSF samples were analyzed. The area under the curve (AUC) value of caspase-1 in CSF during the 5-day period was 2452.9 pg/mL·hr in the group of patients with high ICP vs 617.6 pg/mL·hr in the patients with low ICP. The differences were mainly on day 2 (19.7 pg/mL vs 1.8 pg/mL; p = 0.06) and day 3 (13.9 pg/mL vs 1 pg/mL; p = 0.05). The AUC value of caspase in CSF during the 5-day period was 1918.9 pg/mL·hr in the group of patients with poor outcome versus 924.5 pg/mL·hr in the patients with good outcome. The protein levels of caspase-1 in CSF were higher in patients with unfavorable outcomes during the first 96 hours after TBI.

CONCLUSIONS

In this cohort of patients with TBI who were admitted to the neurosurgical ICU, the inflammasome protein caspase-1 is increased in the CSF of patients with high ICP, especially on days 2 and 3 after TBI. Also the protein levels of caspase-1 in CSF were higher in patients with poor outcome during the first 96 hours after TBI. Moreover, not only the absolute value of caspase-1 in CSF but also its trend is associated with poor outcomes.

Outcomes of very elderly trauma ICU patients. Results from the Spanish trauma ICU registry

OBJECTIVE

To analyze outcomes and factors related to mortality among very elderly trauma patients admitted to intensive care units (ICUs) participating in the Spanish trauma ICU registry.

DESIGN

A multicenter nationwide registry. Retrospective analysis. November 2012-May 2017.

SETTING

Participating ICUs.

PATIENTS

Trauma patients aged ≥80 years.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

The outcomes and influence of limitation of life sustaining therapy (LLST) were analyzed. Comparisons were established using the Wilcoxon test, Chi-squared test or Fisher's exact test as appropriate. Multiple logistic regression analysis was performed to analyze variables related to mortality. A p-value <0.05 was considered statistically significant.

RESULTS

The mean patient age was 83.4±3.3 years; 281 males (60.4%). Low-energy falls were the mechanisms of injury in 256 patients (55.1%). The mean ISS was 20.5±11.1, with a mean ICU stay of 7.45±9.9 days. The probability of survival based on the TRISS methodology was 69.8±29.7%. The ICU mortality rate was 15.5%, with an in-hospital mortality rate of 19.2%. The main cause of mortality was intracranial hypertension (42.7%). The ISS, the need for first- and second-tier measures to control intracranial pressure, and being admitted to the ICU for organ donation were independent mortality predictors. LLST was applied in 128 patients (27.9%). Patients who received LLST were older, with more severe trauma, and with more severe brain injury.

CONCLUSIONS

Very elderly trauma ICU patients presented mortality rates lower than predicted on the basis of the severity of injury.

Hyperlactatemia in ICU patients: Incidence, causes and associated mortality

PURPOSE

To describe the incidence, causes and associated mortality of hyperlactatemia in critically ill patients and to evaluate the association between lactate clearance and in-hospital survival.

METHODS

Retrospective cohort study of patients with hyperlactatemia admitted to the ICU. Hyperlactatemia was defined as a blood lactate concentration ≥5mmol/L and high-grade hyperlactatemia a lactate level ≥10mmol/L. Lactate clearance was calculated as the percentage of decrease in lactate concentration from the peak value.

RESULTS

Of 10,123 patients, 1373 (13.6%) had lactate concentration ≥5mmol/L, and 434(31.6%) of them had ≥10mmol/L. The most common causes of hyperlactatemia were sepsis/septic shock and post-cardiac surgery. An association was found between lactate concentration and in-hospital mortality (p<0.001). The area under the receiver-operating-characteristics (ROC) of lactate concentration and the optimal cut off to predict mortality were 0.72 (0.70-0.75) and 8.6mmol/L, respectively. ROC analysis for lactate clearance to predict in-hospital survival showed that the best area under the curve was obtained at 12h: 0.67 (95% confidence interval 0.59-0.75).

CONCLUSIONS

Hyperlactatemia was common and associated with a high mortality in critically ill patients. Lactate clearance had limited utility for predicting in-hospital survival.

Severe trauma in the geriatric population

Geriatric trauma constitutes an increasingly recognized problem. Aging results in a progressive decline in cellular function which leads to a loose of their capacity to respond to injury. Some medications commonly used in this population can mask or blunt the response to injury. Falls constitute the most common cause of trauma and the leading cause of trauma-related deaths in this population. Falls are complicated by the widespread use of antiplatelets and anticoagulants, especially in patients with brain injury. Under-triage is common in this population. Evaluation of frailty could be helpful to solve this issue. Appropriate triaging and early aggressive management with correction of coagulopathy can improve outcome. Limitation of care and palliative measures must be considered in cases with a clear likelihood of poor prognosis.

Effect of FiO2 in the measurement of VO2 and VCO2 using the E-COXV metabolic monitor

OBJECTIVE

We evaluated the effect of changes in FiO₂ on the bias and accuracy of the determination of oxygen consumption (V˙O₂) and carbon dioxide production (V˙CO₂) using the E-COVX monitor in patients with mechanical ventilation.

DESIGN

Descriptive of concordance.

SETTING

Intensive Care Unit.

PATIENTS OR PARTICIPANTS

Patients with mechanical ventilation.

INTERVENTIONS

We measured V˙O₂ and V˙CO₂ using the E-COVX monitor. Values recorded were the average in 5min. Two groups of 30 patients. We analyzed: 1) the reproducibility in the measurement of V˙O₂ and V˙CO₂ at FiO₂ 0.4, and 2) the effect of the changes in FiO₂ on the measurement of V˙O₂ and V˙CO₂. Statistical analysis was performed using Bland and Altman test.

VARIABLES OF MAIN INTEREST

Bias and accuracy.

RESULTS

1) FiO₂ 0.4 reproducibility: The bias in the measurement of V˙O₂ and V˙CO₂ was 1.6 and 2.1mL/min, respectively, and accuracy was 9.7 to -8.3% and 7.2 to -5.2%, respectively, and 2) effect of FiO₂ on V˙O₂: The bias of V˙O₂ measured at FiO₂ 0.4 and 0.6 was -4.0mL/min and FiO₂ 0.4 and 0.8 was 5.2mL/min. Accuracy between FiO₂ 0.4 and 0.6 was 11.9 to -14.1%, and between FiO₂ 0.4 and 0.8 was 43.9 to -39.7%.

CONCLUSIONS

The E-COVX monitor evaluates V˙O₂ and V˙CO₂ in critical patients with mechanical ventilation with a clinically acceptable accuracy until FiO₂ 0.6.

Scoring severity in trauma: comparison of prehospital scoring systems in trauma ICU patients

PURPOSE

We evaluated the predictive ability of mechanism, Glasgow coma scale, age and arterial pressure (MGAP), Glasgow coma scale, age and systolic blood pressure (GAP), and triage-revised trauma Score (T-RTS) scores in patients from the Spanish trauma ICU registry using the trauma and injury severity score (TRISS) as a reference standard.

METHODS

Patients admitted for traumatic disease in the participating ICU were included. Quantitative data were reported as median [interquartile range (IQR), categorical data as number (percentage)]. Comparisons between groups with quantitative variables and categorical variables were performed using Student's T Test and Chi Square Test, respectively. We performed receiving operating curves (ROC) and evaluated the area under the curve (AUC) with its 95 % confidence interval (CI). Sensitivity, specificity, positive predictive and negative predictive values and accuracy were evaluated in all the scores. A value of p < 0.05 was considered significant.

RESULTS

The final sample included 1361 trauma ICU patients. Median age was 45 (30-61) years. 1092 patients (80.3 %) were male. Median ISS was 18 (13-26) and median T-RTS was 11 (10-12). Median GAP was 20 (15-22) and median MGAP 24 (20-27). Observed mortality was 17.7 % whilst predicted mortality using TRISS was 16.9 %. The AUC in the scores evaluated was: TRISS 0.897 (95 % CI 0.876-0.918), MGAP 0.860 (95 % CI 0.835-0.886), GAP 0.849 (95 % CI 0.823-0.876) and T-RTS 0.796 (95 % CI 0.762-0.830).

CONCLUSIONS

Both MGAP and GAP scores performed better than the T-RTS in the prediction of hospital mortality in Spanish trauma ICU patients. Since these are easy-to-perform scores, they should be incorporated in clinical practice as a triaging tool.

Mortality prediction using TRISS methodology in the Spanish ICU Trauma Registry (RETRAUCI)

OBJECTIVES

To validate Trauma and Injury Severity Score (TRISS) methodology as an auditing tool in the Spanish ICU Trauma Registry (RETRAUCI).

DESIGN

A prospective, multicenter registry evaluation was carried out.

SETTING

Thirteen Spanish Intensive Care Units (ICUs).

PATIENTS

Individuals with traumatic disease and available data admitted to the participating ICUs.

INTERVENTIONS

Predicted mortality using TRISS methodology was compared with that observed in the pilot phase of the RETRAUCI from November 2012 to January 2015. Discrimination was evaluated using receiver operating characteristic (ROC) curves and the corresponding areas under the curves (AUCs) (95% CI), with calibration using the Hosmer-Lemeshow (HL) goodness-of-fit test. A value of p<0.05 was considered significant.

MAIN VARIABLES OF INTEREST

Predicted and observed mortality.

RESULTS

A total of 1405 patients were analyzed. The observed mortality rate was 18% (253 patients), while the predicted mortality rate was 16.9%. The area under the ROC curve was 0.889 (95% CI: 0.867-0.911). Patients with blunt trauma (n=1305) had an area under the ROC curve of 0.887 (95% CI: 0.864-0.910), and those with penetrating trauma (n=100) presented an area under the curve of 0.919 (95% CI: 0.859-0.979). In the global sample, the HL test yielded a value of 25.38 (p=0.001): 27.35 (p<0.0001) in blunt trauma and 5.91 (p=0.658) in penetrating trauma. TRISS methodology underestimated mortality in patients with low predicted mortality and overestimated mortality in patients with high predicted mortality.

CONCLUSIONS

TRISS methodology in the evaluation of severe trauma in Spanish ICUs showed good discrimination, with inadequate calibration - particularly in blunt trauma.

Epidemiology of severe trauma in Spain. Registry of trauma in the ICU (RETRAUCI). Pilot phase

OBJECTIVE

To describe the characteristics and management of severe trauma disease in Spanish Intensive Care Units (ICUs). Registry of trauma in the ICU (RETRAUCI). Pilot phase.

DESIGN

A prospective, multicenter registry.

SETTING

Thirteen Spanish ICUs.

PATIENTS

Patients with trauma disease admitted to the ICU.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

Epidemiology, out-of-hospital attention, registry of injuries, resources utilization, complications and outcome were evaluated.

RESULTS

Patients, n=2242. Mean age 47.1±19.02 years. Males 79%. Blunt trauma 93.9%. Injury Severity Score 22.2±12.1, Revised Trauma Score 6.7±1.6. Non-intentional in 84.4% of the cases. The most common causes of trauma were traffic accidents followed by pedestrian and high-energy falls. Up to 12.4% were taking antiplatelet medication or anticoagulants. Almost 28% had a suspected or confirmed toxic influence in trauma. Up to 31.5% required an out-of-hospital artificial airway. The time from trauma to ICU admission was 4.7±5.3hours. At ICU admission, 68.5% were hemodynamically stable. Brain and chest injuries predominated. A large number of complications were documented. Mechanical ventilation was used in 69.5% of the patients (mean 8.2±9.9 days), of which 24.9% finally required a tracheostomy. The median duration of stay in the ICU and in hospital was 5 (range 3-13) and 9 (5-19) days, respectively. The ICU mortality rate was 12.3%, while the in-hospital mortality rate was 16.0%.

CONCLUSIONS

The pilot phase of the RETRAUCI offers a first impression of the epidemiology and management of trauma disease in Spanish ICUs.

A SIMPLIFIED EQUATION FOR TOTAL ENERGY EXPENDITURE IN MECHANICALLY VENTILATED CRITICALLY ILL PATIENTS

INTRODUCTION

"tight calorie control" concept arose to avoid over- and under-feeding of patients.

OBJECTIVE

to describe and validate a simplified predictive equation of total energy expenditure (TEE) in mechanically ventilated critically ill patients.

METHODS

this was a secondary analysis of measurements of TEE by indirect calorimetry in critically ill patients. Patients were allocated in a 2:1 form by a computer package to develop the new predictive equation TEE (prediction cohort) and the validation cohort. Indirect calorimetry was performed with three different calorimeters: the Douglas-bag, a metabolic computer and the CalorimetR. We developed a new TEE predictive equation using measured TEE (in kcal/kg/d) as dependent variable and as independent variables different factors known to influence energy expenditure: age, gender, body mass index (BMI) and type of injury.

RESULTS

prediction cohort: 179 patients. Validation cohort: 91 patients. The equation was: TEEPE (kcal/Kg/d) = 33 - (3 x A) - (3 x BMI) - (1 x G). Where: A (age in years): ≤ 50 = 0; > 50 = 1. BMI (Kg/m2): 18.5 - 24.9 = 0; 25 - 29.9 = 1; 30 - 34.9 = 2; 35 - 39.9 = 3. G (gender): male = 0; female = 1. The bias (95% CI) was -0.1 (-1.0 - 0.7) kcal/kg/d and the limits of agreement (} 2SD) were -8.0 to 7.8 kcal/kg/d. Predicted TEE was accurate (within 85% to 115%) in 73.6% of patients.

CONCLUSION

the new predictive equation was acceptable to predict TEE in clinical practice for most mechanically ventilated critically ill patients.

Transcranial Sonography and Cerebral Circulatory Arrest in Adults: A Comprehensive Review

The diagnosis of brain death remains a clinical challenge for intensive care unit physicians. Worldwide regulations in its diagnosis may differ, and the need of ancillary tests after a clinical examination is not uniform. Transcranial sonography is a noninvasive, bedside, and widely available technique that can be used in the diagnosis of the cerebral circulatory arrest that preceeds brain death. In this paper we review the general concepts, the technical requisites, the patterns of Doppler signal confirming cerebral circulatory arrest, the vessels to insonate, and the options in cases with poor acoustic window. Future research perspectives in the field of transcranial sonography are discussed as well.