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Biomedical subjects

G Audibert

Publications and source records attributed to G Audibert.

At least 19 recordsLinked to original sources

[Cerebral microdialysis as a clinical tool].

Microdialysis is the only technique available for cerebral metabolic monitoring in the clinical setting. By the mean of a probe inserted in the brain, it provides an extracellular space sampling. Values of various substrates including cerebral glucose, lactate, pyruvate, glycerol or glutamate can be obtained at the bedside at intervals between minutes and hours. Values are critically dependent on the flow of the perfusion liquid and reflect a highly localized cerebral metabolism. Cerebral microdialysis improves our understanding of acute neurological events such as intracranial hypertension or decrease in brain tissue oxygen pressure. Cerebral microdialysis can be used for detection of ischaemia, especially after malignant stroke or vasospasm complicating subarachnoid haemorrhage. In these cases, it may influence the therapeutic management. Moreover, it permits the assessment of metabolic changes after therapeutic interventions. Finally, some markers (like lactate/pyruvate ratio) are related to outcome, especially after traumatic brain injury.

Animals↗

[Anaesthetic management of the patient with acute intracranial hypertension].

Transcranial Doppler and, if possible, measurement of intracranial pressure (ICP) allow preoperative diagnosis of acute intracranial hypertension (ICH) after brain trauma. The main goal of the anaesthesiologist is to prevent the occurrence of secondary brain injuries and to avoid cerebral ischaemia. Treatment of high ICP is mainly achieved with osmotherapy. High-dose mannitol administration (1.4 to 2 g/kg given in bolus doses) may be considered a better option than conventional doses, especially before emergency evacuation of a cerebral mass lesion. Hypertonic saline seems as effective as mannitol without rebound effect and without diuresis increase. Haemostasis should be normalized before neurosurgery and invasive blood pressure monitoring is mandatory. For anaesthesia induction, thiopental or etomidate may be used. In case of ICH, halogenated and nitrous oxide should be avoided. Until the dura is open, mean arterial pressure should be maintained around 90 mmHg (or cerebral perfusion pressure around 70 mmHg). If a long-lasting (several hours) extracranial surgery is necessary, ICP should be monitored and treatment of ICH should have been instituted before.

Acute Disease↗

[Prevention of venous perioperative thromboembolism in ENT and maxillofacial surgery].

There are few studies of poor methodological quality on the risk of thromboembolism in head and neck surgery. The incidence of symptomatic deep vein thrombosis is estimated between, 0.1% and 0.6%. The patient's risk factors (cancer, alcoholism, smoking, malnutrition) determine for the assessment of the potential benefit of thromboembolism prophylaxis. No method can be recommended based on the literature. In patients receiving anticoagulant therapy undergoing superficial head and neck surgery or dental extraction, the literature suggest to continue anticoagulation throughout the perioperative period.

Humans↗

[Thromboprophylaxis in elective spinal surgery and spinal cord injury].

The risk of deep vein thrombosis (DVT) after spinal cord injury is very high. Without prophylaxis the incidence of DVT using venography is 81% and the risk of symptomatic DVT is between 12 and 23%. The risk is much lower in elective spine surgery. After discectomy or laminectomy on less than two spine levels, the risk of DVT is less than 1%. After spinal fusion or extended laminectomy, the risk can be estimated between 0.3 and 2.2%. A prophylaxis is recommended for all patients after spinal cord injury (grade A). The association of a mechanical method and heparin is recommended (grade B). The duration of prophylaxis is 3 months in patients with a motor deficit (grade C). No prophylaxis is recommended after discectomy or limited laminectomy in patients without additional risk factors. Mechanical methods are recommended after spinal fusion or extended laminectomy. For patients with additional risk factors a low molecular weight heparin is recommended.

Ambulatory Surgical Procedures↗

[Thromboprophylaxis in neurosurgery and head trauma].

The incidence of deep vein thrombosis (DVT) is between 20 and 35% using contrast venography, with a rate of symptomatic DVT between 2.3 and 6% in neurosurgery without any prophylaxis. The risk of DVT is poorly evaluated in head injured patients but is around 5%. Specific risk factors in neurosurgery are: a motor deficit, a meningioma or malignant tumour, a large tumour, age over 60 years, surgery lasting more than 4 hours, a chemotherapy. The benefit of mechanical methods or low molecular weight heparin (LMWH) for the prevention of DVP in neurosurgery is demonstrated (grade A). Each method decreases the risk by about 50%. A postoperative prophylaxis with a LMWH does not seem to increase the risk of intracranial bleeding (grade C). There is no demonstrated benefit to begin a prophylaxis with LMWH before the intervention. The duration of the prophylaxis is 7 to 10 days but this has not been scientifically determined.

Craniocerebral Trauma↗