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Introduced into the human population in December 2019, the zoonotic novel β-coronavirus spread rapidly. Labeled Coronavirus Disease 2019 (COVID-19) by the World Health Organization (WHO), the infection reached pandemic proportions by March 11, 2020. At the time of writing this commentary, globally our way of life is transforming. Hospitals are no exception, with mobilization into an emergency mode including halting all non-urgent elective procedures and clinic visits. The Centers for Disease Control and Prevention (CDC) and the WHO are currently recommending aggressive measures to prevent viral transmission. For healthcare workers, aside from standard precautions like using personal protective equipment (PPE) and handwashing, these bodies are strongly encouraging the practice of ‘social distancing’ (SD) and ‘self-quarantine’ (SQ) for those with suspected or proven infections. In essence, SD means avoiding crowds, closing schools, canceling all social events and meetings, and maintaining a 6-foot distance between individuals. SQ refers to isolating oneself for 2 weeks without any social contact to avoid transmission. These efforts will be critical to mitigating covid-19 spread, as they may ‘flatten the curve’ of new and serious cases and prevent the healthcare system from being overwhelmed. Healthcare workers are on the front line, and doctors, nurses, and hospital staff are at highest risk of contracting the virus. As cases become ubiquitous throughout the healthcare system, many staff will become secondarily infected and will require medical treatment and SQ. As the volume of infected personnel increases, many services will need to operate on a skeleton crew. If infection breaches a critical threshold, some emergency services may cease to be possible. The greatest potential impact will be on mechanical thrombectomy (MT) in acute ischemic stroke. MT for emergent large vessel occlusion (ELVO) represents one of the most impactful and effective emergent interventions in medicine,1 markedly reducing morbidity and mortality. MT is …

Background The glymphatic pathway transports cerebrospinal fluid through the brain, thereby facilitating waste removal. A unique aspect of this pathway is that its function depends on the state of consciousness of the brain and is associated with norepinephrine activity. A current view is that all anesthetics will increase glymphatic transport by inducing unconsciousness. This view implies that the effect of anesthetics on glymphatic transport should be independent of their mechanism of action, as long as they induce unconsciousness. We tested this hypothesis by comparing the supplementary effect of dexmedetomidine, which lowers norepinephrine, with isoflurane only, which does not. Methods Female rats were anesthetized with either isoflurane (N = 8) or dexmedetomidine plus low-dose isoflurane (N = 8). Physiologic parameters were recorded continuously. Glymphatic transport was quantified by contrast-enhanced magnetic resonance imaging. Cerebrospinal fluid and gray and white matter volumes were quantified from T1 maps, and blood vessel diameters were extracted from time-of-flight magnetic resonance angiograms. Electroencephalograms were recorded in separate groups of rats. Results Glymphatic transport was enhanced by 32% in rats anesthetized with dexmedetomidine plus low-dose isoflurane when compared with isoflurane. In the hippocampus, glymphatic clearance was sixfold more efficient during dexmedetomidine plus low-dose isoflurane anesthesia when compared with isoflurane. The respiratory and blood gas status was comparable in rats anesthetized with the two different anesthesia regimens. In the dexmedetomidine plus low-dose isoflurane rats, spindle oscillations (9 to 15 Hz) could be observed but not in isoflurane anesthetized rats. Conclusions We propose that anesthetics affect the glymphatic pathway transport not simply by inducing unconsciousness but also by additional mechanisms, one of which is the repression of norepinephrine release.

There has been a long-standing debate regarding the optimal approach to the anesthetic management of patients undergoing mechanical thrombectomy. While the vast majority of intracranial neurointerventional procedures are performed under general anesthesia (GA), thrombectomy has been treated differently. Thrombectomy cases are fundamentally different from traditional cases in that they occur at all hours of the day (and night) and always represent a time-critical emergency. At many institutions the anesthetic management of these patients is left to the available general on-call anesthesia staff, or sometimes they are performed without an anesthesiologist at all. It is the rare exception that a dedicated, experienced, on-call cerebrovascular anesthesia team is available. As thrombectomy has become established as the standard of care for emergent large vessel occlusion (ELVO), it is time that neurointerventional surgery evolves in the same direction as have other subspecialties such as cardiothoracic surgery, which typically have a dedicated, specialized, anesthesia team. Until recently, most studies had suggested that GA led to higher mortality rates and worse neurological outcomes for thrombectomy patients. In general, these studies were methodologically weak, inherently biased, and either post hoc analyses of prospective studies or altogether retrospective. To date, three randomized controlled trials have analyzed this very …