Short summary

The project is a substudy in a Ph.D. project in cerebral metabolism at the neurosurgical department of Odense University Hospital. It is the aim of the investigators to evaluate prevalens and duration of the specific microdialysis patterns of mitochondrial dysfunction in neurocritical patients as well as investigating the possible role of jugular bulb microdialysis in these patients and possible correlations to cerebral microdialysis, parenchymal oxygen partial pressure and outcome.

Rationale

Acute cerebral mitochondrial dysfunction (MD) is a major factor in neurocritical patients in several diseases. It is characterized by non-efficiency of mitochondria (ATP-producing organelles in all cells) in cerebral tissue in spite of ample perfusion and it leads to cell death and hence poorer patient outcome. Our group has recently described how biochemical patterns from cerebral microdialysis can diagnose MD. The fact that cerebral microdialysis only measures regional values in the brain and is intracranially invasive, however, limits usability, and surrogate measures in use today as Near InfraRed Spectroscopy (NIRS, as often used for assessment of cerebral function) correlates poorly to cerebral metabolic status.

Aims

We aim to describe the impact of mitochondrial dysfunction in patients admitted to the Neurointensive Care Unit (NICU) with severe subarachnoid haemorrhage. Furthermore, we will evaluate a completely new method of cerebral metabolic monitoring, namely microdialysis of cerebral venous blood drainage. The cerebral venous drainage (all the blood passing the brain) passes without exception through the jugular bulbs, and most of the flow is to either left or right side depending on dominance.

We hypothesize that the metabolic measurements from the central venous outflow (jugular bulb) mirrors the overall cerebral metabolism and can be used in the diagnosis of cerebral mitochondrial dysfunction.

Methods

In the current prospective cohort study, unconscious patients admitted to the NICU in Odense will be implanted with a frontal lobe cerebral microdialysis catheter as well as jugular bulb microdialysis catheter and monitored for 5 days or until arousal. Clinical data, radiology, intracranial pressure and tissue oxygen pressure will together with our combined microdialysis data be recorded and analyzed. Clinical outcome will be assessed at 6 months.

Perspectives

If jugular bulb microdialysis can be confirmed to give a reliable global estimate of cerebral metabolic state we might be able to implement a new, less invasive diagnostic tool for NICU-patients with implications for future treatment of neurocritical patients.

Description of the cohort

Unconcious adults admitted to the NICU at OUH with confirmed intracaranial lesion. Children, pregnant women and patients with untreated coagulopathy are not included.

Data and biological material

Clinical data and registerdata from the Danish stroke registry.

Collaborating researchers and departments

Department of Neurosurgery, Odense University Hospital

• Professor and Consultant Frantz Rom Poulsen
• Consultant and Associate professor Troels Halfeld Nielsen
• Associate professor Carl-Henrik Nordstrøm