European legislation impedes critical care research and fails to protect patients' rights

The European Clinical Trials Directive requires an informed consent from the patient or a proxy in drug trials. Although informed consent is a valuable tool to protect patients' rights in clinical trials, this requirement largely impedes research in critical care settings, and if pursued in this context, it does not provide the patient with adequate protection. Instead of insisting on informed consent, we suggest that the focus should be shifted towards two other ethically relevant elements in human experimentation: risk assessment and selection of research subjects. When reviewing protocols in which a waiver of consent is deemed necessary, the Ethical Review Board should ensure that non-therapeutic risks are minimal, that the research is specifically designed to benefit critically ill patients, and that it cannot be conducted under circumstances where an informed consent can be obtained. If the European Directive is changed accordingly, this permits clinical trials in critical care settings, while adequate protection from risky non-therapeutic procedures is ensured and exploitation of the patient as an easily accessible research subject is prevented

Acute myocardial infarction and syncope in an 18-year-old athlete with an abnormal origin of the left coronary artery: a case report

We report a case of acute myocardial infarction and syncope in an 18-year-old athlete during high-performance exercise. A coronary arteriography and an angiographic computed tomography scan subsequently revealed a left coronary arterial origin from the right aortic sinus along with an intramural course of the left main stem. The patient was successfully treated with surgical unroofing of the left main stem from inside the aorta. To our knowledge, this is the first report demonstrating this type of anomaly pre- and postoperatively by use of angiographic computed tomography scan in the context of acute coronary syndrome

Cerebral net exchange of large neutral amino acids after lipopolysaccharide infusion in healthy humans

INTRODUCTION: Alterations in circulating large neutral amino acids (LNAAs), leading to a decrease in the plasma ratio between branched-chain and aromatic amino acids (BCAA/AAA ratio), may be involved in sepsis-associated encephalopathy. We hypothesised that a decrease in the BCAA/AAA ratio occurs along with a net cerebral influx of the neurotoxic AAA phenylalanine in a human experimental model of systemic inflammation. METHODS: The BCAA/AAA ratio, the cerebral delivery, and net exchange of LNAAs and ammonia were measured before and 1 hour after a 4-hour intravenous infusion of Escherichia coli lipopolysaccharide (LPS) in 12 healthy young men. RESULTS: LPS induced systemic inflammation, reduced the BCAA/AAA ratio, increased the cerebral delivery and unidirectional influx of phenylalanine, and abolished the net cerebral influx of the BCAAs leucine and isoleucine. Furthermore, a net cerebral efflux of glutamine, which was independent of the cerebral net exchange of ammonia, was present after LPS infusion. CONCLUSIONS: Systemic inflammation may affect brain function by reducing the BCAA/AAA ratio, thereby changing the cerebral net exchange of LNAAs

Neuro-oxidative-nitrosative stress in sepsis

Neuro-oxidative-nitrosative stress may prove the molecular basis underlying brain dysfunction in sepsis. In the current review, we describe how sepsis-induced reactive oxygen and nitrogen species (ROS/RNS) trigger lipid peroxidation chain reactions throughout the cerebrovasculature and surrounding brain parenchyma, due to failure of the local antioxidant systems. ROS/RNS cause structural membrane damage, induce inflammation, and scavenge nitric oxide (NO) to yield peroxynitrite (ONOO−). This activates the inducible NO synthase, which further compounds ONOO− formation. ROS/RNS cause mitochondrial dysfunction by inhibiting the mitochondrial electron transport chain and uncoupling oxidative phosphorylation, which ultimately leads to neuronal bioenergetic failure. Furthermore, in certain ‘at risk' areas of the brain, free radicals may induce neuronal apoptosis. In the present review, we define a role for ROS/RNS-mediated neuronal bioenergetic failure and apoptosis as a primary mechanism underlying sepsis-associated encephalopathy and, in sepsis survivors, permanent cognitive deficits