Anaesthetic Management of the Patient With Ischaemic Stroke
Anaesthetic Management of the Patient With Ischaemic Stroke
A survey of members of the Society for Vascular and Interventional Neurology (SVIN) found that interventional surgeons felt the most important limitation of general anaesthesia and the main reason for not preferring it for all cases was time delay. Time delay to therapy is indeed a major concern in therapy for the patient with acute ischaemic stroke. The target of therapy in acute ischaemic stroke is the ischaemic penumbra, which is the threatened but salvageable tissue surrounding the infarct core. The ischaemic penumbra is short-lived, lasting only for a few hours in human patients. The typical ischaemic stroke patient loses 1.9 million neurones for each minute they are untreated. Compared with the normal rate of neurone loss in brain ageing, the ischaemic brain ages 3.6 yr each hour without treatment. Recanalization of occluded arteries is a necessary, but not sufficient, condition for achieving good clinical outcomes with endovascular therapy. If the entire tissue at risk has already progressed to irreversible infarction, reperfusion will be futile, and can even cause harm by increasing the risk of haemorrhagic transformation.
Although induction of general anaesthesia and the involvement of an anaesthesia care team could conceivably delay endovascular treatment of acute ischaemic stroke, most studies show no difference in time from patient arrival to treatment for patients receiving general anaesthesia or local anaesthesia. A single institutional study did find a significantly longer arrival to groin puncture time in patients who received general anaesthesia. In contrast, interventional procedure time has been noted to be less for patients who receive general anaesthesia. Although this is true in reported studies, there can be substantial variability between institutions. It is critical to remember the race to save the penumbra and avoid delay of therapy.
Time Is Brain
A survey of members of the Society for Vascular and Interventional Neurology (SVIN) found that interventional surgeons felt the most important limitation of general anaesthesia and the main reason for not preferring it for all cases was time delay. Time delay to therapy is indeed a major concern in therapy for the patient with acute ischaemic stroke. The target of therapy in acute ischaemic stroke is the ischaemic penumbra, which is the threatened but salvageable tissue surrounding the infarct core. The ischaemic penumbra is short-lived, lasting only for a few hours in human patients. The typical ischaemic stroke patient loses 1.9 million neurones for each minute they are untreated. Compared with the normal rate of neurone loss in brain ageing, the ischaemic brain ages 3.6 yr each hour without treatment. Recanalization of occluded arteries is a necessary, but not sufficient, condition for achieving good clinical outcomes with endovascular therapy. If the entire tissue at risk has already progressed to irreversible infarction, reperfusion will be futile, and can even cause harm by increasing the risk of haemorrhagic transformation.
Although induction of general anaesthesia and the involvement of an anaesthesia care team could conceivably delay endovascular treatment of acute ischaemic stroke, most studies show no difference in time from patient arrival to treatment for patients receiving general anaesthesia or local anaesthesia. A single institutional study did find a significantly longer arrival to groin puncture time in patients who received general anaesthesia. In contrast, interventional procedure time has been noted to be less for patients who receive general anaesthesia. Although this is true in reported studies, there can be substantial variability between institutions. It is critical to remember the race to save the penumbra and avoid delay of therapy.
