We read with great interest the special article entitled “Perioperative Ultrasound Training in Anesthesiology: A Call to Action” by Mahmood et al1 that included a pertinent discussion on the emerging use of perioperative ultrasonography. We commend the authors for their commentary and agree with their call to action regarding perioperative ultrasound in anesthesiology.
We would like to suggest an important addition to the discussion of the current and potential uses for perioperative ultrasound and encourage the consideration of Transcranial Doppler Ultrasonography (TCD) as an essential tool for all anesthesiologists and, in particular, neuroanesthesiologists. As cardiac anesthesiologists “gain” important insights into cardiac function with echocardiography, so can neuroanesthesiologists “probe” the dynamic cerebrovascular circulation with TCD. First described by Aaslid,2 TCD offers important real-time insight into cerebrovascular anatomy and hemodynamics. The technology is widely used periprocedurally, ranging from carotid endarterectomy to selectively determine the need for shunt to emboli detection during cardiopulmonary bypass procedures.3,4 In addition, indications in the critical care arena vary from detection of vasospasm, to elevated intracranial pressure, to confirmatory testing for cerebral circulatory arrest and brain death. It is unfortunate that the technology is not applied more generally and would be a shame to not include TCD training in the curricula of anesthesiology trainees.
As neuroanesthesia works to define itself as a subspecialty and work toward accreditation and standardization of fellowship training, knowledge of TCD would be an important subspecialty skill set for the budding neuroanesthesiologist. For those who desire to demonstrate a more in-depth knowledge base, the American Society of Neuroimaging offers an examination and guidelines with certification for the interpretation of not only TCD, but also carotid duplex.
As Mahmood et al1 so elegantly conclude, “…the clinical applications of perioperative ultrasound are expanding rapidly, and its use will become a standard of care in multiple clinical settings,” let us not leave behind the important applications of ultrasound in neuroanesthesiology.
Brian E. Schmidt, MD
Swedish Neuroscience Institute
Swedish Medical Center
Neuroanesthesiology Fellow
Seattle, Washington
Arthur M. Lam, MD
Department of Anesthesiology and Pain Medicine
University of Washington
Attending Neurointensivist
Medical Director of Neuroanesthesia
Medical Director of Cerebrovascular Laboratory
Swedish Neuroscience Institute
Swedish Medical Center
Seattle, Washington
REFERENCES
1. Mahmood F, Matyal R, Skubas N, et al. Perioperative ultrasound training in anesthesiology: a call to action. Anesth Analg. 2016;122:17941804.
2. Aaslid R, Markwalder TM, Nornes H. Noninvasive transcranial Doppler ultrasound recording of flow velocity in basal cerebral arteries. J Neurosurg. 1982;57:769774.
3. Lam AM, Kianpour D. Monitoring for carotid endarterectomy: more or less? Anesth Analg. 2015;120:11861188.
4. Patel N, Minhas JS, Chung EM. Intraoperative embolization and cognitive decline after cardiac surgery: a systematic review. Semin Cardiothorac Vasc Anesth. 2016;20:225231.
