ARDS Mortality Prediction Model Using Evolving Clinical Data and Chest Radiograph Analysis.

INTRODUCTION: Within primary ARDS, SARS-CoV-2-associated ARDS (C-ARDS) emerged in late 2019, reaching its peak during the subsequent two years. Recent efforts in ARDS research have concentrated on phenotyping this heterogeneous syndrome to enhance comprehension of its pathophysiology. METHODS AND RESULTS: A retrospective study was conducted on C-ARDS patients from April 2020 to February 2021, encompassing 110 participants with a mean age of 63.2 ± 11.92 (26-83 years). Of these, 61.2% (68) were male, and 25% (17) experienced severe ARDS, resulting in a mortality rate of 47.3% (52). Ventilation settings, arterial blood gases, and chest X-ray (CXR) were evaluated on the first day of invasive mechanical ventilation and between days two and three. CXR images were scrutinized using a convolutional neural network (CNN). A binary logistic regression model for predicting C-ARDS mortality was developed based on the most influential variables: age, PaO2/FiO2 ratio (P/F) on days one and three, CNN-extracted CXR features, and age. Initial performance assessment on test data (23 patients out of the 110) revealed an area under the receiver operating characteristic (ROC) curve of 0.862 with a 95% confidence interval (0.654-0.969). CONCLUSION: Integrating data available in all intensive care units enables the prediction of C-ARDS mortality by utilizing evolving P/F ratios and CXR. This approach can assist in tailoring treatment plans and initiating early discussions to escalate care and extracorporeal life support. Machine learning algorithms for imaging classification can uncover otherwise inaccessible patterns, potentially evolving into another form of ARDS phenotyping. The combined features of these algorithms and clinical variables demonstrate superior performance compared to either element alone.

Adding Extracorporeal Membrane Oxygenation to Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest Due to Pulmonary Embolism: A Case Report.

We present a challenging cardiopulmonary resuscitation scenario of an out-of-hospital cardiac arrest (OHCA) in a 21-year-old healthy woman recovering from a lower limb fracture who collapsed during a rehabilitation session at a community center. The combination of witnessed arrest, administration of immediate cardiopulmonary resuscitation, and effective communication to emergency services enabled a timely cannulation of extracorporeal membrane oxygenation in a cardiopulmonary resuscitation reference center. The cause of the cardiac arrest was pulmonary embolism, and the intensive care unit team opted for thrombolysis when she arrived after 40 minutes of cardiopulmonary resuscitation. The circulatory support given by venoarterial extracorporeal membrane oxygenation enabled adequate perfusion until the restoration of cardiac blood flow at 75 minutes after cardiac arrest. Despite the initial success, several life-threatening complications occurred. Anticoagulation is of paramount importance during extracorporeal support, as is thrombolysis in massive pulmonary embolism with cardiac arrest. However, this led to several complications. We highlight the importance of liaising with a wider team in such cases, including hepatobiliary surgery, vascular surgery, and interventional radiology, as doing so saved this patient's life without deficits.

Candida auris in Intensive Care Setting: The First Case Reported in Portugal.

Candida auris is an opportunistic human pathogen that has rapidly spread to multiple countries and continents and has been associated with a high number of nosocomial outbreaks. Herein, we report the first case of C. auris in Portugal, which was associated with a patient transferred from Angola to an ICU in Portugal for liver transplantation after a SARS-CoV-2 infection. C. auris was isolated during the course of bronchoalveolar lavage, and it was subjected to antifungal susceptibility testing and whole-genome sequence analysis. This isolate presents low susceptibility to azoles and belongs to the genetic clade III with a phylogenetic placement close to African isolates. Although clade III has already been reported in Europe, taking into account the patient's clinical history, we cannot discard the possibility that the patient's colonization/infection occurred in Angola, prior to admission in the Portuguese hospital. Considering that C. auris is a fungal pathogen referenced by WHO as a critical priority, this case reinforces the need for continuous surveillance in a hospital setting.

Cholesteryl hemiazelate identified in CVD patients causes in vitro and in vivo inflammation.

Oxidation of PUFAs in LDLs trapped in the arterial intima plays a critical role in atherosclerosis. Though there have been many studies on the atherogenicity of oxidized derivatives of PUFA-esters of cholesterol, the effects of cholesteryl hemiesters (ChEs), the oxidation end products of these esters, have not been studied. Through lipidomics analyses, we identified and quantified two ChE types in the plasma of CVD patients and identified four ChE types in human endarterectomy specimens. Cholesteryl hemiazelate (ChA), the ChE of azelaic acid (n-nonane-1,9-dioic acid), was the most prevalent ChE identified in both cases. Importantly, human monocytes, monocyte-derived macrophages, and neutrophils exhibit inflammatory features when exposed to subtoxic concentrations of ChA in vitro. ChA increases the secretion of proinflammatory cytokines such as interleukin-1ß and interleukin-6 and modulates the surface-marker profile of monocytes and monocyte-derived macrophage. In vivo, when zebrafish larvae were fed with a ChA-enriched diet, they exhibited neutrophil and macrophage accumulation in the vasculature in a caspase 1- and cathepsin B-dependent manner. ChA also triggered lipid accumulation at the bifurcation sites of the vasculature of the zebrafish larvae and negatively impacted their life expectancy. We conclude that ChA behaves as an endogenous damage-associated molecular pattern with inflammatory and proatherogenic properties.

The Impact of the Serum Extraction Protocol on Metabolomic Profiling Using UPLC-MS/MS and FTIR Spectroscopy.

Biofluid metabolomics is a very appealing tool to increase the knowledge associated with pathophysiological mechanisms leading to better and new therapies and biomarkers for disease diagnosis and prognosis. However, due to the complex process of metabolome analysis, including the metabolome isolation method and the platform used to analyze it, there are diverse factors that affect metabolomics output. In the present work, the impact of two protocols to extract the serum metabolome, one using methanol and another using a mixture of methanol, acetonitrile, and water, was evaluated. The metabolome was analyzed by ultraperformance liquid chromatography associated with tandem mass spectrometry (UPLC-MS/MS), based on reverse-phase and hydrophobic chromatographic separations, and Fourier transform infrared (FTIR) spectroscopy. The two extraction protocols of the metabolome were compared over the analytical platforms (UPLC-MS/MS and FTIR spectroscopy) concerning the number of features, the type of features, common features, and the reproducibility of extraction replicas and analytical replicas. The ability of the extraction protocols to predict the survivability of critically ill patients hospitalized at an intensive care unit was also evaluated. The FTIR spectroscopy platform was compared to the UPLC-MS/MS platform and, despite not identifying metabolites and consequently not contributing as much as UPLC-MS/MS in terms of information concerning metabolic information, it enabled the comparison of the two extraction protocols as well as the development of very good predictive models of patient's survivability, such as the UPLC-MS/MS platform. Furthermore, FTIR spectroscopy is based on much simpler procedures and is rapid, economic, and applicable in the high-throughput mode, i.e., enabling the simultaneous analysis of hundreds of samples in the microliter range in a couple of hours. Therefore, FTIR spectroscopy represents a very interesting complementary technique not only to optimize processes as the metabolome isolation but also for obtaining biomarkers such as those for disease prognosis.

Complications during transport of adult patients on extracorporeal membrane oxygenation.

INTRODUCTION: Transport on extracorporeal membrane oxygenation (ECMO) is a risky and complex procedure. Although most published data support the feasibility of interhospital transport on ECMO, data concerning intra-facility transportation and frequency and severity of complications during ECMO transport of adult patients are still scarce. The aim of this study was to assess transport arrangements and complications during intra and interhospital ECMO-supported patients transport at a high-volume ECMO center. METHODS: Retrospective single-center descriptive study evaluating the prevalence and severity of complications associated with the transportation of adult patients on ECMO support between 2014 and 2022 in our ECMO center. RESULTS: We performed 393 transfers of patients on ECMO support. Those comprised 206 intra-facility, 147 primary, 39 secondary and one tertiary transports. For primary and tertiary transportations, the average transfer length was 118.6 km (range 2.5-1446) and the mean total transport time was 5 h 40 min. The majority of transportations were made by ambulance (93.2%). Complications occurred in 12.7% of all transports and were more frequent in intra-facility and primary/tertiary transfers. Most complications were patient (46%) and staff related (26%). Risk category two was the most frequent (50%), and only five complications were classified as risk category 1 (10%). No deaths occurred during all patient transport. CONCLUSIONS: Most transports carry minor problems that entail a negligible risk to the patient. When ECMO-supported transport is performed by an experienced team, the severe complications are not related with an increased morbimortality.

The Characteristics and Laboratory Findings of SARS-CoV-2 Infected Patients during the First Three COVID-19 Waves in Portugal-A Retrospective Single-Center Study.

Background and Objectives: Given the wide spectrum of clinical and laboratory manifestations of the coronavirus disease 2019 (COVID-19), it is imperative to identify potential contributing factors to patients' outcomes. However, a limited number of studies have assessed how the different waves affected the progression of the disease, more so in Portugal. Therefore, our main purpose was to study the clinical and laboratory patterns of COVID-19 in an unvaccinated population admitted to the intensive care unit, identifying characteristics associated with death, in each of the first three waves of the pandemic. Materials and Methods: This study included 337 COVID-19 patients admitted to the intensive care unit of a single-center hospital in Lisbon, Portugal, between March 2020 and March 2021. Comparisons were made between three COVID-19 waves, in the second (n = 325) and seventh (n = 216) days after admission, and between discharged and deceased patients. Results: Deceased patients were considerably older (p = 0.021) and needed greater ventilatory assistance (p = 0.023), especially in the first wave. Differences between discharged and deceased patients' biomarkers were minimal in the first wave, on both analyzed days. In the second wave significant differences emerged in troponins, lactate dehydrogenase, procalcitonin, C-reactive protein, and white blood cell subpopulations, as well as platelet-to-lymphocyte and neutrophil-to-lymphocyte ratios (all p < 0.05). Furthermore, in the third wave, platelets and D-dimers were also significantly different between patients' groups (all p < 0.05). From the second to the seventh days, troponins and lactate dehydrogenase showed significant decreases, mainly for discharged patients, while platelet counts increased (all p < 0.01). Lymphocytes significantly increased in discharged patients (all p < 0.05), while white blood cells rose in the second (all p < 0.001) and third (all p < 0.05) waves among deceased patients. Conclusions: This study yields insights into COVID-19 patients' characteristics and mortality-associated biomarkers during Portugal's first three COVID-19 waves, highlighting the importance of considering wave variations in future research due to potential significant outcome differences.

Infection Biomarkers Based on Metabolomics.

Current infection biomarkers are highly limited since they have low capability to predict infection in the presence of confounding processes such as in non-infectious inflammatory processes, low capability to predict disease outcomes and have limited applications to guide and evaluate therapeutic regimes. Therefore, it is critical to discover and develop new and effective clinical infection biomarkers, especially applicable in patients at risk of developing severe illness and critically ill patients. Ideal biomarkers would effectively help physicians with better patient management, leading to a decrease of severe outcomes, personalize therapies, minimize antibiotics overuse and hospitalization time, and significantly improve patient survival. Metabolomics, by providing a direct insight into the functional metabolic outcome of an organism, presents a highly appealing strategy to discover these biomarkers. The present work reviews the desired main characteristics of infection biomarkers, the main metabolomics strategies to discover these biomarkers and the next steps for developing the area towards effective clinical biomarkers.

Cytokine Adsorption Therapy during Extracorporeal Membrane Oxygenation in Adult Patients with COVID-19.

Respiratory failure and systemic inflammation are paramount features of severe SARS-CoV-2 disease (COVID-19). Extracorporeal membrane oxygenation (ECMO) therapy has a potential role in patients with refractory disease. An inflammatory response due to blood contact with hemofilters, functioning as a synergic inflammatory stimulus, can lead to a hyperinflammatory state, relatable to cytokine release syndromes. After the first patient succumbed to a refractory vasodilatory shock believed to be due to hyperinflammatory state, a strategy of blood purification through cytokine adsorption therapy (CAT) with CytoSorb® was designed. In this case series, the authors describe the initial experience with such strategy. CAT was employed with no direct complications and helped controlling the inflammatory state, with all patients halting vasopressor support in 72 h and biomarker levels (C-reactive protein, ferritin, and interleukin-6) showing negative trends in most patients. Analysis of inflammatory biomarkers evolution highlighted 2 biomarker profiles related to the presence or absence of superinfection at the time of CAT implementation. In this case series of severe COVID-19 patients, 3 patients died - irreversible lung fibrosis, complications of critical hypoxemia before ECMO induction and complications of systemic anticoagulation were the causes. This case series aimed to contribute to the body of evidence substantiating CAT utilization in hyperinflammatory patients, namely, COVID-19 patients requiring ECMO rescue.

REPAIR OF RUPTURED ABDOMINAL AORTIC ANEURYSM AFTER CARDIAC ARREST: A CASE REPORT.

The management of abdominal aortic aneurysms, especially ruptured abdominal aortic aneurysms, continues to challenge vascular surgeons. A ruptured abdominal aortic aneurysm is associated with a high mortality rate. If cardiopulmonary resuscitation is required before surgical repair, mortality rates are said to be even higher. However, cardiac arrest in patients with ruptured abdominal aortic aneurysm does not accurately predict a nonsalvageable state or preclude functional survival. In these cases, agressive management may be the only hope for survival, and cardiac arrest should not as such contraindicate repair. The objective of this study is to present a successful case of repair of ruptured abdominal aortic aneurysm after cardiac arrest.

Is the efficacy of remdesivir so different from that of lopinavir-ritonavir in severe COVID-19? The answer by real time-PCR: a narrative review.

This letter discusses the efficacy of current antiviral therapy used in severe COVID-19 infection. Since the first severe cases were documented, several antiviral options have been studied as adjuncts to standard supportive care [1, 2]. Firstly, the combination of lopinavir-ritonavir resurrected from SARS and MERS outbreaks and soon abandoned after the publication of several trials like the randomized controlled trial RECOVERY, which concluded that it was not associated with reductions in 28-day mortality, duration of hospital stay, or risk of progression to invasive mechanical ventilation or death [3]. Remdesivir is currently the only antiviral agent approved for the treatment of COVID-19. It is recommended for use in hospitalized patients who require supplemental oxygen. However, it is not routinely recommended for patients who require mechanical ventilation due to the lack of data showing any benefit at this advanced stage of the disease [4-6].

User-Experience with Haptic Feedback Technologies and Text Input in Interactive Multimedia Devices.

Remote control devices are commonly used for interaction with multimedia equipment and applications (e.g., smart TVs, gaming, etc.). To improve conventional keypad-based technologies, haptic feedback and user input capabilities are being developed for enhancing the UX and providing advanced functionalities in remote control devices. Although the sensation provided by haptic feedback is similar to mechanical push buttons, the former offers much greater flexibility, due to the possibility of dynamically choosing different mechanical effects and associating different functions to each of them. However, selecting the best haptic feedback effects among the wide variety that is currently enabled by recent technologies, remains a challenge for design engineers aiming to optimise the UX. Rich interaction further requires text input capability, which greatly influences the UX. This work is a contribution towards UX evaluation of remote control devices with haptic feedback and text input. A user evaluation study of a wide variety of haptic feedback effects and text input methods is presented, considering different technologies and different number of actuators on a device. The user preferences, given by subjective evaluation scores, demonstrate that haptic feedback has undoubtedly a positive impact on the UX. Moreover, it is also shown that different levels of UX are obtained, according to the technological characteristics of the haptic actuators and how many of them are used on the device.

Prognostic significance of specific EEG patterns after cardiac arrest in a Lisbon Cohort.

OBJECTIVE: To evaluate if EEG patterns considered highly malignant are reliable predictors not only of poor neurological outcome but also reliable predictors of death. METHODS: Retrospectively, EEGs from Cardiac Arrest (CA) patients of two teaching hospitals in Lisbon were classified into 3 groups: highly malignant, malignant, and benign groups. Outcome was assessed at 6 months after CA by CPC (Cerebral Performance Categories) scale. We evaluated the accuracy of these patterns to predict poor neurological outcome and death. RESULTS: We included 106 patients for analysis. All patients with a highly malignant EEG (n = 37) presented a poor neurological outcome. Those patterns were also associated with death. Malignant EEG patterns were not associated with poor neurological outcome. Benign EEG patterns were associated with good neurological recovery (p < 0.0001). CONCLUSION: Highly malignant EEG patterns were strongly associated with poor neurological outcome and can be considered to be predictors of death. SIGNIFICANCE: This study increased the knowledge about the value of EEG as a tool in outcome prediction of patients after cardiac arrest.

Practical applications of nutritional scores.

PURPOSE OF REVIEW: Any intensive therapy requires individual adaptation, despite the standardization of the concepts that support them. Among these therapies, nutritional care has repeatedly been shown to influence clinical outcome. In order to evaluate the risk of malnutrition among critically ill patients and to identify those patients who may benefit from medical nutrition therapy is imperative to have a validated screening tool to optimize nutritional care.The scope of this review is to analyze the recent literature on the management of nutritional scores for patients admitted to the ICU. RECENT FINDINGS: Critically ill patient staying for more than 24-48 h in the ICU, if unable to eat, should be considered at risk for malnutrition. Several nutritional tools have been proposed but not all are validated to screening those patients. The limitations of existing screening tools are described. SUMMARY: Nutritional scores should be routinely performed at ICU admission according to recommended guidelines. An approach to incorporate these tools into everyday clinical practice is suggested.

Time of admission to intensive care unit, strained capacity, and mortality: A retrospective cohort study.

PURPOSE: We sought to study the association between afterhours ICU admission and ICU mortality considering measures of strained ICU capacity. MATERIALS AND METHODS: Retrospective analysis of 4141 admissions to 2 ICUs in Lisbon, Portugal (06/2016-06/2018). Primary exposure was ICU admission on 20:00 h-07:59 h. Primary outcome was ICU mortality. Measures of strained ICU capacity were: bed occupancy rate ≥ 90% and cluster of ICU admissions 2 h before or following index admission. RESULTS: There were 1581 (38.2%) afterhours ICU admissions. Median APACHE II score (19 vs. 20) was similar between patients admitted afterhours and others (P = .27). Patients admitted afterhours had higher crude ICU mortality (15.4% vs. 21.9%; P < .001), but similar adjusted ICU mortality (aOR [95%CI] = 1.15 [0.97-1.38]; P = .12). While bed occupancy rate ≥ 90% was more frequent in patients admitted afterhours (23.1% vs. 29.1%) or deceased in ICU (23.6% vs. 33.7%), cluster of ICU admissions was more frequent in patients admitted during daytime hours (75.2% vs. 58.9%) or that survived the ICU stay (70.1% vs. 63.9%; P ≤ .001 for all). These measures of strained ICU capacity were not associated with adjusted ICU mortality (P ≥ .10 for both). CONCLUSIONS: Afterhours ICU admission and measures of strained ICU capacity were associated with crude but not adjusted ICU mortality.

Acute-on-Chronic Liver Failure: A Portuguese Single-Center Reference Review.

Acute-on-chronic liver failure (ACLF) is a syndrome characterized by an acute deterioration of a patient with cirrhosis, frequently associated with multi-organ failure and a high short-term mortality rate. We present a retrospective study that aims to characterize the presentation, evolution, and outcome of patients diagnosed with ACLF at our center over the last 3 years, with a comparative analysis between the group of patients that had ACLF precipitated by infectious insults of bacterial origin and the group of those with ACLF triggered by a nonbacterial infectious insult; the incidence of acute kidney injury and its impact on the prognosis of ACLF was also analyzed. Twenty-nine patients were enrolled, the majority of them being male (89.6%), and the mean age was 53 years. Fourteen patients (48.3%) developed ACLF due to a bacterial infectious event, and 9 of them died (64.2%, overall mortality rate 31%); however, no statistical significance was found (p < 0.7). Of the remaining 15 patients (51.7%) with noninfectious triggers, 11 died (73.3%, overall mortality rate 37.9%); again there was no statistical significance (p < 0.7). Twenty-four patients (83%) developed acute kidney injury (overall mortality rate 65.5%; p < 0.022) at the 28-day and 90-day follow-up. Twelve patients had acute kidney injury requiring renal replacement therapy (41.37%; overall mortality rate 37.9%; p < 0.043). Hepatic transplant was performed in 3 patients, with a 100% survival at the 28-day and 90-day follow-up (p < 0.023). Higher grades of ACLF were associated with increased mortality (p < 0.02; overall mortality 69%). CONCLUSIONS: ACLF is a heterogeneous syndrome with a variety of precipitant factors and different grades of extrahepatic involvement. Most cases will have some degree of renal dysfunction, with an increased risk of mortality. Hepatic transplant is an efficient form of therapy for this syndrome.

A Doença Hepática Crónica Agudizada/Falência é um síndrome caracterizado por uma deterioração aguda de um doente com cirrose, frequentemente associada com falência multiorgânica e elevada mortalidade a curto prazo. Apresentamos estudo retrospetivo que teve como objetivo caracterizar a apresentação, evolução e prognóstico de doentes diagnosticados com Doença Hepática Crónica Agudizada/Falência no nosso Centro nos últimos 3 anos, comparando o grupo de doentes que tiveram Doença Hepática Crónica provocada por infeções bacterianas e os doentes com Doença Hepática Crónica Agudizada/Falência desencadeada por precipitantes que não a infeção bacteriana; foi também analisada a incidência de lesão renal aguda e o seu impacto no prognóstico na Doença Hepática Crónica Agudizada/Falência. Vinte e nove doente foram incluídos no estudo, a maioria do género masculino (89.6%), idade media de 53 anos. Catorze doentes (48.3%) desenvolveram Doença Hepática Crónica Agudizada devido a infeção bacteriana, 9 dos quais faleceram (64.2%, mortalidade global 31%), contudo, sem significado estatístico (p < 0.7); dos restantes 15 (51.7%) sem infeção bacteriana, 11 faleceram (73.3%, mortalidade global 37.9%), também sem significado estatístico (p < 0.7%). Vinte e quatro doentes (83%) desenvolveram lesão renal, mortalidade global de 65.5% (p < 0.022) aos 28 e 90 dias de seguimento. Doze doentes desenvolveram lesão renal aguda com necessidade de terapêutica de substituição da função renal (41.37%), mortalidade global de 37.9% (p < 0.043). O transplante hepático foi realizado em 3 doentes, com uma sobrevida de 100% aos 28 e 90 dias de seguimento (p < 0.023); Graus elevados de Doença Hepática Crónica Agudizada estão associadas a mortalidade mais elevada (p < 0.02); mortalidade global de 69%. CONCLUSIONS: A Doença Hepática Crónica Agudizada é um síndrome heterogéneo, com uma variedade de fatores precipitantes e diferentes graus de envolvimento extra-hepático; a maioria das situações estará associada a disfunção renal, com aumento do risco de mortalidade; O transplante hepático será uma eficaz de tratamento deste síndrome.

Monitorização do sistema nervoso autônomo em ambiente de cuidados intensivos como ferramenta de prognóstico. Revisão sistemática / Autonomic nervous system monitoring in intensive care as a prognostic tool. Systematic review

RESUMO Objetivo: Apresentar uma revisão sistemática do uso da monitorização do sistema nervoso autônomo como ferramenta de prognóstico, verificando a variabilidade da frequência cardíaca nas unidades de cuidados intensivos. Métodos: Revisão de literatura publicada até julho de 2016 na PubMed/MEDLINE de estudos realizados em unidades de cuidados intensivos, sobre a monitorização do sistema nervoso autônomo, por meio da análise da variabilidade da frequência cardíaca, como ferramenta de prognóstico - estudo da mortalidade. Foram utilizados os seguintes termos em inglês no campo de pesquisa: ("autonomic nervous system" OR "heart rate variability") AND ("intensive care" OR "critical care" OR "emergency care" OR "ICU") AND ("prognosis" OR "prognoses" OR "mortality"). Resultados: A probabilidade de morte nos doentes aumentou com a diminuição da variabilidade da frequência cardíaca, estudada por meio da variância da frequência cardíaca, desacoplamento cardíaco, volatilidade da frequência cardíaca, integer heart rate variability, desvio padrão de todos os intervalos RR normais, raiz quadrada da média do quadrado das diferenças entre intervalos RR adjacentes, poder total, componente de baixa frequência, componente de muito baixa frequência, razão entre o componente de baixa frequência e o componente de alta frequência), razão entre expoentes fractais de curto e longo prazo, entropia de Shannon, entropia multiescalar e entropia aproximada. Conclusão: Nos doentes internados em unidades de cuidados intensivos, independentemente da patologia que motivou o internamento, a variabilidade da frequência cardíaca varia de forma inversa com a gravidade clínica e com o prognóstico.

ABSTRACT Objective: To present a systematic review of the use of autonomic nervous system monitoring as a prognostic tool in intensive care units by assessing heart rate variability. Methods: Literature review of studies published until July 2016 listed in PubMed/Medline and conducted in intensive care units, on autonomic nervous system monitoring, via analysis of heart rate variability as a prognostic tool (mortality study). The following English terms were entered in the search field: ("autonomic nervous system" OR "heart rate variability") AND ("intensive care" OR "critical care" OR "emergency care" OR "ICU") AND ("prognosis" OR "prognoses" OR "mortality"). Results: There was an increased likelihood of death in patients who had a decrease in heart rate variability as analyzed via heart rate variance, cardiac uncoupling, heart rate volatility, integer heart rate variability, standard deviation of NN intervals, root mean square of successive differences, total power, low frequency, very low frequency, low frequency/high frequency ratio, ratio of short-term to long-term fractal exponents, Shannon entropy, multiscale entropy and approximate entropy. Conclusion: In patients admitted to intensive care units, regardless of the pathology, heart rate variability varies inversely with clinical severity and prognosis.

Autonomic nervous system monitoring in intensive care as a prognostic tool. Systematic review. / Monitorização do sistema nervoso autônomo em ambiente de cuidados intensivos como ferramenta de prognóstico. Revisão sistemática.

OBJECTIVE: To present a systematic review of the use of autonomic nervous system monitoring as a prognostic tool in intensive care units by assessing heart rate variability. METHODS: Literature review of studies published until July 2016 listed in PubMed/Medline and conducted in intensive care units, on autonomic nervous system monitoring, via analysis of heart rate variability as a prognostic tool (mortality study). The following English terms were entered in the search field: ("autonomic nervous system" OR "heart rate variability") AND ("intensive care" OR "critical care" OR "emergency care" OR "ICU") AND ("prognosis" OR "prognoses" OR "mortality"). RESULTS: There was an increased likelihood of death in patients who had a decrease in heart rate variability as analyzed via heart rate variance, cardiac uncoupling, heart rate volatility, integer heart rate variability, standard deviation of NN intervals, root mean square of successive differences, total power, low frequency, very low frequency, low frequency/high frequency ratio, ratio of short-term to long-term fractal exponents, Shannon entropy, multiscale entropy and approximate entropy. CONCLUSION: In patients admitted to intensive care units, regardless of the pathology, heart rate variability varies inversely with clinical severity and prognosis.

OBJETIVO: Apresentar uma revisão sistemática do uso da monitorização do sistema nervoso autônomo como ferramenta de prognóstico, verificando a variabilidade da frequência cardíaca nas unidades de cuidados intensivos. MÉTODOS: Revisão de literatura publicada até julho de 2016 na PubMed/MEDLINE de estudos realizados em unidades de cuidados intensivos, sobre a monitorização do sistema nervoso autônomo, por meio da análise da variabilidade da frequência cardíaca, como ferramenta de prognóstico - estudo da mortalidade. Foram utilizados os seguintes termos em inglês no campo de pesquisa: ("autonomic nervous system" OR "heart rate variability") AND ("intensive care" OR "critical care" OR "emergency care" OR "ICU") AND ("prognosis" OR "prognoses" OR "mortality"). RESULTADOS: A probabilidade de morte nos doentes aumentou com a diminuição da variabilidade da frequência cardíaca, estudada por meio da variância da frequência cardíaca, desacoplamento cardíaco, volatilidade da frequência cardíaca, integer heart rate variability, desvio padrão de todos os intervalos RR normais, raiz quadrada da média do quadrado das diferenças entre intervalos RR adjacentes, poder total, componente de baixa frequência, componente de muito baixa frequência, razão entre o componente de baixa frequência e o componente de alta frequência), razão entre expoentes fractais de curto e longo prazo, entropia de Shannon, entropia multiescalar e entropia aproximada. CONCLUSÃO: Nos doentes internados em unidades de cuidados intensivos, independentemente da patologia que motivou o internamento, a variabilidade da frequência cardíaca varia de forma inversa com a gravidade clínica e com o prognóstico.