Assessment of cerebral oxygenation in neurocritical care patients: comparison of a new four wavelengths forehead regional saturation in oxygen sensor (EQUANOX®) with brain tissue oxygenation. A prospective observational study.

BACKGROUND: Because of restricted information given by monitoring solely intracranial pressure and cerebral perfusion pressure, assessment of the cerebral oxygenation in neurocritical care patients would be of interest. The aim of this study was to determinate the correlation between the non-invasive measure regional saturation in oxygen (rSO2) with a third generation NIRS monitor and an invasive measure of brain tissue oxygenation tension (PbtO2). METHODS: We conducted a prospective, observational, unblinded study including neurocritical care patients requiring a PbtO2 monitoring. Concomitant measurements of rSO2 were performed with a four wavelengths forehead sensor (EQUANOX Advance®) of the EQUANOX® 7600 System. We determined the correlation between rSO2 and PbtO2 and the ability of the rSO2 to detect ischemic episodes defined by a PbtO2 less than 15 mmHg. The rSO2 ischemic threshold was 60%. RESULTS: During 2 months, 8 consecutives patients, including 275 measurements, were studied. There was no correlation between rSO2 and PbtO2 (r=0.016 [-0.103-0.134], r2=0.0003, P=0.8). On the 86 ischemic episodes detected by PbtO2, only 13 were also detected by rSO2. ROC curve showed the inability for rSO2 to detect cerebral hypoxia episodes (AUC=0.54). CONCLUSION: rSO2 cannot be used as a substitute for PbtO2 to monitor cerebral oxygenation in neurocritical care patients.

[Ischemic strokes as a presenting feature of marantic endocarditis despite heparin treatment]. / Accidents cérébraux ischémiques sous héparine révélateurs d'endocardites marastiques.

We report on two patients hospitalized in intensive care unit for ischemic strokes presenting the feature of marantic endocarditis complicating lung's adenocarcinoma. These two cases turned out to be very interesting because of the occurrence of ischemic strokes even though the patients were receiving the recommended treatment, namely anticoagulation with heparin, in well-adjusted doses. The management of nonbacterial thrombotic endocarditis remains a challenge and its mortality is still high.

Decompressive craniectomy guided by cerebral microdialysis and brain tissue oxygenation in a patient with meningitis.

Bacterial meningitis remains a life-threatening disease mainly due to intracranial hypertension. However, decompressive craniectomy (DC) and the use of cerebral microdialysis (MD) and brain tissue oxygen pressure measurement (pTiO(2) ) are poorly described in this disease. We report a case of a 56-year-old woman admitted for severe bacterial meningitis complicating mastoiditis. Despite maximal medical treatment, intracranial pressure increased above 30 mmHg, with a decline in pTiO(2) and MD results indicating cerebral ischaemia. A bilateral DC was performed. Neurological outcome was favourable, and on discharge, the patient was able to live independently. This is the first report of DC in meningitis guided by cerebral MD and pTiO(2) . Invasive multimodal neuromonitoring should be used in severe meningitis and DC could be considered in the case of refractory intracranial hypertension.

[Carotid dissection during angioplasty for vasospasm induced by subarachnoid haemorrhage. The use of multimodal cerebral monitoring]. / Dissection carotidienne au cours d'une angioplastie pour vasospasme après hémorragie sous-arachnoïdienne. Apport du monitorage cérébral "multimodal".

We report the case of a 54-year-old woman presenting subarachnoid haemorrhage. She experienced multiple vasospasms and treatment included triple-H (hypervolaemia, hypertension, and haemodilution) and endovascular therapies. Right internal carotid dissection complicated angioplasty of the right middle cerebral artery. Combined brain tissue partial pressure of oxygen monitoring and transcranial echo-Doppler could have facilitated early diagnosis. Despite successful revascularization of right internal carotid by stenting, this complication caused acute stroke with refractory intracranial hypertension.

Cerebral microdialysis and P(ti)O2 for neuro-monitoring before decompressive craniectomy.

We report the case of a young patient with post-traumatic, intractable, intracranial hypertension leading to craniectomy. This intracranial hypertension was preceded by focal signs of ischemia diagnosed through P(ti)O2 monitoring and cerebral microdialysis, and occurred a few hours prior to a decrease in cerebral perfusion pressure below 60 mmHg. The neurological outcome was satisfactory with a Glasgow Outcome Scale of 4 at 3 months. We discuss the potential interest of such neuro-monitoring to determine the optimal time for performing a craniectomy.

[Clinical use of bedside cerebral microdialysis: a review]. / Utilisation clinique du monitorage biochimique cérébral par microdialyse: revue de la littérature.

OBJECTIVE: To review the current data on clinical bedside use of cerebral microdialysis. DATA SOURCE: Search through Medline database of articles in French and English (keywords: microdialysis, cerebral ischaemia, head trauma, subarachnoid haemorrhage, clinical study). STUDY SELECTION: All clinical articles published between 1995 and 2005, including original papers and some case reports. DATA SYNTHESIS: Microdialysis after occlusive stroke has shown elevated levels of glutamate and lactate. When space-occupying oedema develops, biochemistry abnormalities occur first, before ICP increases. Bedside microdialysis appears to be a sensitive and earlier indicator of space occupying oedema. Most Accurate markers to monitor ischaemia induced by vasospasm are glutamate and lactate/pyruvate ratio. These markers are earlier than clinical abnormalities or pressure measurements (sensibility 82%, specificity 89%). In the field of head trauma, the same compounds were utilised. The level of these compounds correlates with outcome in a different manner whether the area studied is close to a concussion or not. Most of biochemical events are linked to global cerebral ischaemia. We can observe some abnormalities limited to the pericontusional area, which are not detected by the global monitoring. Microdialysis appears a useful tool to investigate disease mechanisms but cannot be recommended for a widespread use after head trauma. CONCLUSION: Bedside cerebral microdialysis allows clinical decisions in the setting of subarachnoid haemorrhage and ischaemic stroke. It represents a valuable tool to investigate head trauma pathophysiology.

[A sudden C3-C4 tetraplegia revealing an intracranial dural arteriovenous draining into the spinal medullary veins]. / Tétraplégie brutale C3-C4 révélant une fistule durale artérioveineuse intracrânienne à drainage veineux périmédullaire.

We report a case of intracranial dural arteriovenous (DAVF) draining into the spinal medullary veins. A 49-year-old woman presented a rapidly progressive ascending myelopathy resulting in a C3-C4 tetraplegia associated with acute respiratory failure at the twelfth hour. MRI revealed swelling of the cervical spinal cord, hyperintensity on T2 and enhancement of enlarged veins on MR angiography. A conventional angiography showed the DAVF with venous drainage into the spinal vein extending to the conus medullaris. After embolization, neurological recovery occurred during the first week, allowing tracheal extubation on day 2. Clinical, radiological and therapeutic aspects of this uncommon pathology are presented.

Nitric oxide inhalation is useful in the management of right ventricular failure caused by myocardial contusion.

We report a severe head injury and blunt chest trauma with sternal and multiple rib fractures with high-energy impact in a 22-year-old man. Twelve hours after the accident, haemodynamic status of the patient rapidly worsened because of right ventricular (RV) failure due to myocardial contusion, requiring increasing doses of catecholamine. Nitric oxide inhalation was used to decrease RV afterload, and produced an immediate improvement in haemodynamic status, permitting a decrease in catecholamine administration. From days 2 through 8, cardiac function continued to improve, and was normal on day 9. Nitric oxide inhalation was stopped on day 4.

Sufentanil supplementation of sevoflurane during induction of anaesthesia: a randomized study.

BACKGROUND AND OBJECTIVE: The use of opioids with sevoflurane for induction of anaesthesia is associated with fewer reactions to laryngoscopy but increases the risk of apnoea. Thus it is important to search for the optimal opioid dose. The aim of this study was to compare two sufentanil doses during induction with sevoflurane in young adults. METHODS: Sixty-three young patients (18-26 yr) undergoing wisdom-tooth extraction were randomly allocated to one of the two sufentanil dose groups: 0.15 microg kg(-1) (n = 33) or 0.30 microg kg(-1) (n = 30). Sufentanil was injected 1 min before sevoflurane inhalation. Sevoflurane was inhaled using the three-breath vital-capacity technique with 8% sevoflurane and 100% oxygen. The anaesthesiologist decided when to intubate the trachea. The length of time for intubation was measured. In addition, any apnoea, patient movement, adequacy of the laryngoscopic view, coughing and haemodynamic responses were recorded. RESULTS: Mean time to intubate the trachea, full laryngoscopy view and open-cord position were similar in both groups. The incidence of apnoea was higher in Group 0.30 (P < 0.05). The incidence of patient movement (P < 0.05) and coughing (P < 0.001) was lower in Group 0.30 than in Group 0.15. Sufentanil 0.30 microg kg(-1) attenuated the change in heart rate more effectively than sufentanil 0.15 microg kg(-1). Mean arterial pressure was similar and stable in both groups during induction of anaesthesia. CONCLUSIONS: In current clinical practice during sevoflurane induction, sufentanil 0.30 microg kg(-1) provided a better quality of induction than sufentanil 0.15 microg kg(-1), without significant cardiovascular depression, although the risk of apnoea is increased.

[Brainstem anesthesia after peribulbar anesthesia]. / Anesthésie du tronc cérébral après anesthésie péribulbaire.

We report a case of pupilloplasty under peribulbar anaesthesia complicated by a brainstem anaesthesia requiring tracheal intubation and mechanical ventilation. Immediate outcome was good. We discuss the different mechanisms of this complication. The subarachnoidal (intrathecal) injection of local anaesthesic seems to be the most probable cause. The use of short needles should theoretically decrease the risk. Despite all these precautions, peribulbar anaesthesia should not be considered as an ordinary procedure.