1/7. Temporary occlusion of middle cerebral artery by macroembolism in carotid surgery.Two patients are presented who during carotid endarterectomy (CEA) temporarily showed an obstruction of the middle cerebral artery (MCA) mainstem by a macroembolus resulting in cerebral ischaemia. Both cases are unusual examples of CEA and selected from a cohort of more than 1,500 operations. During surgery with general anaesthesia, brain function was monitored with computerized electroencephalography (EEG) and transcranial Doppler (TCD) ultrasonography. The simultaneous use of EEG and TCD monitoring allowed us to witness the development of intraoperative cerebral ischaemia and to relate these events to a temporary occlusion of the MCA mainstem by a macroembolus. This is the first life report that describes obstruction of a cerebral artery by arterial embolism resulting in cerebral ischaemia.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
2/7. blood pressure manipulation during awake carotid surgery to reverse neurological deficit after carotid cross-clamping.We describe the management of three patients undergoing awake carotid surgery who developed signs of cerebral ischaemia after carotid cross-clamping. Drug treatment to increase arterial blood pressure above baseline reversed the neurological deficit and an internal carotid artery shunt was not needed. Shunt insertion is less frequent with regional rather than general anaesthesia, and blood pressure control can reduce this even more. Coincidentally, one of the patients, who gave a history of angina of effort after walking 100 m, complained of chest pain after cross-clamp release. This was treated successfully with sublingual nitroglycerin before ST segment changes became apparent on the ECG. These reports suggest that regional anaesthesia for carotid surgery allows potential complications to be identified earlier than under general anaesthesia using reports from the patient, so that treatment may be modified to prevent morbidity and even mortality.- - - - - - - - - - ranking = 3keywords = anaesthesia (Clic here for more details about this article) |
3/7. A case of gliosarcoma appearing as ischaemic stroke.OBJECTIVES: Ischaemic stroke attributable to malignant brain tumour is a rarely reported phenomenon and even various imaging techniques including angiography do not necessarily lead to an accurate diagnosis. CASE DESCRIPTION: A 46-year-old, previously healthy man developed apoplectic symptoms with slight right sided hemiparesis and global aphasia. The computed tomography (CT) scan showed lesions of the left temporal lobe and the paraventricular white matter suggestive of left middle cerebral artery (MCA) infarction. Carotid angiography demonstrated compression of the M1 segment of the MCA and occlusion of temporal MCA. The patient initially refused magnetic resonance imaging (MRI) because of claustrophobia. Because of fluctuating symptoms and successive worsening of the condition over weeks an MRI scan was conducted under general anaesthesia. Beneath temporal, opercular, and subcortical infarctions it revealed a left temporal tumour. A tumour biopsy disclosed a gliosarcoma (WHO grade IV). Microscopical examination of the surgical specimen demonstrated invasion of tumour cells into the wall of a greater pre-existing blood vessel. CONCLUSIONS: Malignant brain tumours may cause ischaemic infarction. This is a rare but important differential diagnosis for the origin of strokes. The authors describe the first case with infiltration of intracranial blood vessels by tumour cells of a gliosarcoma.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
4/7. Perioperative management of a cadasil type arteriopathy patient.We report the anaesthetic management of a patient suffering from an ischaemic arteriopathy of the cadasil (cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy) type. The anaesthetic implications of this pathology are discussed. By analogy with other cerebral arteriopathies, the aim of our management was to keep mean arterial blood pressure and end-tidal carbon dioxide so as to prevent any cerebral ischaemic or vasospastic phenomenon. We preserved the cerebral venous return by avoiding excessive head-down position. We used a balanced anaesthetic technique because it allows easier titration of the depth of anaesthesia with regard to mean arterial pressure. There is no contraindication to the use of loco-regional anaesthesia.- - - - - - - - - - ranking = 2keywords = anaesthesia (Clic here for more details about this article) |
5/7. Increased oxygen administration during awake carotid surgery can reverse neurological deficit following carotid cross-clamping.We describe the management of two patients undergoing awake carotid surgery who developed signs of cerebral ischaemia following cross-clamping of the internal carotid artery. Administration of oxygen 100% with a close-fitting anaesthetic facemask reversed the neurological deficit, avoiding the need for insertion of an internal carotid artery shunt. Thus, the incidence of shunt insertion, which is reduced by the use of regional rather than general anaesthesia, could be reduced further by supplementary oxygenation. The possible mechanism and implications are discussed.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
6/7. Barbiturate therapy in the management of cerebral ischaemia.Two patients who underwent surgery for cerebral aneurysms are presented. In the first case 31 g thiopentone were given postoperatively over 20 h after the patient had already been comatose for many hours. Such high doses raise considerable problems in patient management. In the second case a loading dose of 50 mg/kg thiopentone was given prophylactically to a patient undergoing cerebral aneurysm surgery beginning at the induction of anaesthesia and before surface cooling was begun. Cerebral activity was monitored continuously with a cerebral function monitor (CFM). There was no significant cardiovascular depression, little delay in postoperative recovery and no permanent neurological sequelae. In cerebral aneurysm surgery, cerebral oedema following cerebral ischaemia, either associated with vasospasm or resulting from surgical occlusion of vessels, remains a major problem postoperatively and may be an indication for preventive treatment with barbiturates. The author contend that this technique merits further evaluation in cerebro-vascular surgery, especially in high risk cases.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
7/7. Cerebral protection using retrograde cerebral perfusion during hypothermic circulatory arrest.BACKGROUND: Retrograde cerebral perfusion through the superior vena cava (SVC) has been proposed to protect the brain from ischaemic injury during profound hypothermic circulatory arrest (PHCA). Its contribution to cerebral protection is unclear. Furthermore, the addition of anaesthetic or vasodilating agents to the SVC perfusate to enhance brain protection, has never been described. methods: In three patients undergoing repair of the ascending aorta utilizing PHCA, the upper body was retrogradely perfused with cold (16 degrees C) blood through the SVC by the cardiopulmonary bypass pump. Electroencephalographic activity was monitored using a computerized electroencephalographic monitor (Cerebro Trac 2500, SRD). perfusion pressure was measured at a port in the cannula connector. etomidate or thiopentone was injected into the SVC perfusate to arrest reappearing electroencephalographic activity. nitroglycerin or nitroprusside was injected into the perfusate to increase retrograde flow and maintain a constant perfusion pressure. RESULTS: During PHCA periods of up to 61 min, recurrent electroencephalographic activity was abolished by the retrograde administration of small boluses of etomidate (total 50 mg) or thiopentone (total 500 mg). nitroprusside (100 micrograms) and nitroglycerin (2 micrograms.kg-1.min-1) increased retrograde flow from 220 to 550 and 660 ml.min-1, respectively, while maintaining perfusion pressure (25-26 mmHg). Recovery from anaesthesia and surgery was uneventful, with no adverse neurological sequelae. CONCLUSION: Injection of anaesthetic agents into the retrograde SVC perfusate during PHCA, can suppress reoccurring electroencephalographic activity and retrograde injection of vasodilators can facilitate an increase in perfusion. It is suggested that both may augment brain protection.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |