Brain hemodynamics in septic patients.

Brain dysfunction is a frequent complication of sepsis. Most likely, sepsis-associated brain dysfunction (SABD) results from the interaction between multiple factors: neurodegeneration due to microglial activation, altered neurotransmission, neuroinflammation and impairment of cerebral macro- and microcirculation. Altered brain perfusion might results from several mechanism: global or regional alterations in cerebral blood flow (CBF); reduced cerebral perfusion pressure - which is the driving force propelling blood through cerebral blood vessels - due to systemic hypotension; global or regional vasoconstriction; dysfunction of the intrinsic regulatory mechanisms of CBF, such as cerebral autoregulation and cerebrovascular reactivity; endothelial and blood-brain barrier dysfunction; autonomic nervous system dysfunction and metabolic uncoupling.

Critically ill patients with acute kidney injury: clinical determinants and post-mortem histology.

Background: Acute kidney injury (AKI) requiring renal replacement therapy (RRT) in the intensive care unit (ICU) portends a poor prognosis. We aimed to better characterize predictors of survival and the mechanism of kidney failure in these patients.

Methods: This was a retrospective observational study using clinical and radiological electronic health records, analysed by univariable and multivariable binary logistic regression.

Estimated Cerebral Perfusion Pressure and Intracranial Pressure in Septic Patients.

Background: Sepsis-associated brain dysfunction (SABD) is frequent and is associated with poor outcome. Changes in brain hemodynamics remain poorly described in this setting. The aim of this study was to investigate the alterations of cerebral perfusion pressure and intracranial pressure in a cohort of septic patients.

The association between the presence and burden of periodic discharges and outcome in septic patients: an observational prospective study.

Background: Sepsis-associated encephalopathy (SAE) is frequent in septic patients. Electroencephalography (EEG) is very sensitive to detect early epileptic abnormalities, such as seizures and periodic discharges (PDs), and to quantify their duration (the so-called burden). However, the prevalence of these EEG abnormalities in septic patients, as well as their effect on morbidity and mortality, are still unclear.

Correlation between heart rate variability and cerebral autoregulation in septic patients.

Background: Heart rate variability (HRV) may provide an estimation of the autonomous nervous system (ANS) integrity in critically ill patients. Disturbances of cerebral autoregulation (CAR) may share common pathways of ANS dysfunction.

Aim: To explore whether changes in HRV and CAR index correlate in critically ill septic patients.

Cerebral Autoregulation Indices Are Not Interchangeable in Patients With Sepsis.

Introduction: Dynamic cerebral autoregulation (dCA) is frequently altered in patients with sepsis and may be associated with sepsis-associated brain dysfunction. However, the optimal index to quantify dCA in patients with sepsis is currently unknown.

Objective: To assess the agreement between two validated dCA indices in patients with sepsis.

Cerebral autoregulation in anoxic brain injury patients treated with targeted temperature management.

Background: Little is known about the prevalence of altered CAR in anoxic brain injury and the association with patients' outcome. We aimed at investigating CAR in cardiac arrest survivors treated by targeted temperature management and its association to outcome.

Methods: Retrospective analysis of prospectively collected data.

The Prognostic Value of Brain Dysfunction in Critically Ill Patients with and without Sepsis: A Analysis of the ICON Audit.

Brain dysfunction is associated with poor outcome in critically ill patients. In a post hoc analysis of the Intensive Care over Nations (ICON) database, we investigated the effect of brain dysfunction on hospital mortality in critically ill patients. Brain failure was defined as a neurological sequential organ failure assessment (nSOFA) score of 3-4, based on the assumed Glasgow Coma Scale (GCS) score.

Delay of cerebral autoregulation in traumatic brain injury patients.

Introduction: Adequate cerebral perfusion prevents secondary insult after traumatic brain injury (TBI). Cerebral autoregulation (CAR) keeps cerebral blood flow (CBF) constant when arterial blood pressure (ABP) changes. Aim of the study was to evaluate the existence of delayed CAR in TBI patients and its possible association with outcome.

The use of automated pupillometry to assess cerebral autoregulation: a retrospective study.

Background: Critically ill patients are at high risk of developing neurological complications. Among all the potential aetiologies, brain hypoperfusion has been advocated as one of the potential mechanisms. Impairment of cerebral autoregulation (CAR) can result in brain hypoperfusion.

Cerebrospinal Fluid Glucose and Lactate Levels After Subarachnoid Hemorrhage: A Multicenter Retrospective Study.

Background: In patients with subarachnoid hemorrhage (SAH), abnormalities in glucose and lactate metabolism have been described using cerebral microdialysis. Glucose and lactate concentrations in cerebrospinal fluid (CSF) are more easily accessible, but scarce data are available in this setting. The aim of this study is to assess the relationship of CSF glucose and lactate with blood concentrations and with unfavorable neurological outcome after SAH.

Renin as a Marker of Tissue-Perfusion and Prognosis in Critically Ill Patients.

Objectives: To characterize renin in critically ill patients. Renin is fundamental to circulatory homeostasis and could be a useful marker of tissue-perfusion. However, diurnal variation, continuous renal replacement therapy and drug-interference could confound its use in critical care practice.

Impaired cerebral autoregulation is associated with brain dysfunction in patients with sepsis.

Background: Sepsis-associated brain dysfunction (SABD) is associated with high morbidity and mortality. The pathophysiology of SABD is multifactorial. One hypothesis is that impaired cerebral autoregulation (CAR) may result in brain hypoperfusion and neuronal damage leading to SABD.

Septic Encephalopathy.

Purpose Of The Review: To discuss the diagnostic approach to patients with septic encephalopathy as well as the need for specific neuro-monitoring and the perspectives on future therapeutic approaches in this setting.

Recent Findings: Most of data-concern experimental studies evaluating the pathophysiology of septic encephalopathy. A combination of neurodegenerative pathways with neurovascular injury is the cornerstone for the development of such complication and the long-term neurological sequelae among survivors.

Six-Month Outcome of Immunocompromised Patients with Severe Acute Respiratory Distress Syndrome Rescued by Extracorporeal Membrane Oxygenation. An International Multicenter Retrospective Study.

Because encouraging rates for hospital and long-term survival of immunocompromised patients in ICUs have been described, these patients are more likely to receive invasive therapies, like extracorporeal membrane oxygenation (ECMO). To report outcomes of immunocompromised patients treated with ECMO for severe acute respiratory distress syndrome (ARDS) and to identify their pre-ECMO predictors of 6-month mortality and main ECMO-related complications. Retrospective multicenter study in 10 international ICUs with high volumes of ECMO cases.

Is There a Role for Enterohormones in the Gastroparesis of Critically Ill Patients?

Objectives: Delayed gastric emptying occurs in critically ill patients and impairs the delivery, digestion, and absorption of enteral feeding. A pathophysiologic role of the enterohormones peptide YY and ghrelin is supported by preclinical data. To compare the circulating plasma levels of peptide YY and ghrelin in control subjects and in critically ill patients, during feeding and fasting, and to search for a correlation with gastric emptying.

Anemia management after acute brain injury.

Anemia is frequent among brain-injured patients, where it has been associated with an increased risk of poor outcome. The pathophysiology of anemia in this patient population remains multifactorial; moreover, whether anemia merely reflects a higher severity of the underlying disease or is a significant determinant of the neurological recovery of such patients remains unclear. Interestingly, the effects of red blood cell transfusions (RBCT) in moderately anemic patients remain controversial; although hemoglobin levels are increased, different studies observed only a modest and inconsistent improvement in cerebral oxygenation after RBCT and raised serious concerns about the risk of increased complications.

Noninvasive Vascular Methods for Detection of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage.

The development of delayed cerebral ischemia after subarachnoid hemorrhage is one of the most important determinants of poor neurologic outcome. The pathophysiology of delayed cerebral ischemia relies on a complex interplay between a significant reduction of the diameter of large intracranial arteries (vasospasm), microvascular disturbances, and spreading cortical depolarization that lead to an inadequate oxygen supply to the brain parenchyma. The early diagnosis of cerebral vasospasm is a real challenge for clinicians and requires a multimodal approach to evaluate the consequences of vascular narrowing on cerebral function.

Optimizing sedation in patients with acute brain injury.

Daily interruption of sedative therapy and limitation of deep sedation have been shown in several randomized trials to reduce the duration of mechanical ventilation and hospital length of stay, and to improve the outcome of critically ill patients. However, patients with severe acute brain injury (ABI; including subjects with coma after traumatic brain injury, ischaemic/haemorrhagic stroke, cardiac arrest, status epilepticus) were excluded from these studies. Therefore, whether the new paradigm of minimal sedation can be translated to the neuro-ICU (NICU) is unclear.