The Daily Dose • Thursday, June 3, 2021

Searching for Solutions to Medicine’s Biggest Problems

Mark Arcario, MD, PhD

The Early Stage Anesthesiology Scholars (eSAS) put together an excellent panel of junior faculty, fellows, and residents across the specialty. The panel, “Going Up: Early Stage Anesthesiology Scholars Rapid-Fire Showcase,” presented on May 16 at the IARS 2021 Annual Meeting, showcased the wide range of research subjects and techniques anesthesiologists are bringing to bear on medicine’s biggest problems.

Broc Burke, MD, PhD, Clinical Instructor of Anesthesiology at Washington University in St. Louis, presented an interesting look at his work on utilizing near-infrared optical techniques in determining ischemic stroke severity and evolution. Following time-dependent patterns in near-infrared absorption differences in oxyhemoglobin and deoxyhemoglobin, Dr. Burke’s portable optical device was able to detect ischemic brain tissue with a significant degree of accuracy. This could potentially revolutionize monitoring for patients with ischemic stroke and their clinical course.

Erica Langnas, MD, Resident Physician in the Department of Anesthesiology at University of California, San Francisco, analyzed what factors from inpatient pain regimens are leading to outpatient opioid prescriptions in postsurgical patients. Via a retrospective, single-center analysis, Dr. Langnas noted that since the mid-2010s, the use of analgesic adjuncts in a multimodal scheme has been steadily increasing, which has led to a concomitant decrease in inpatient opioid prescriptions. Despite this, however, patients are still being prescribed a significant dose of opioids on discharge, even in excess of what they required in the hospital. Indeed, in patients who did not require any opioids as an inpatient, the vast majority were still prescribed opioids in an outpatient setting. This work provides a path forward for further reducing outpatient opioid burden, by highlighting another area where vigilance can be applied.

Loren Smith, MD, PhD, Assistant Professor of Anesthesiology at Vanderbilt University Medical Center, examined the role of high-density lipoproteins (HDL) in the development of acute kidney injury (AKI). As HDL has been shown to have anti-inflammatory properties as well as promoting endothelial health, it is thought to potentially play a protective role in the development of AKI. Analysis of perioperative patients demonstrated that higher perioperative HDL levels correlated with lower changes from baseline creatinine and lower rates of AKI development. It is known, however, that perioperative administration of atorvastatin, which raises HDL levels, is not protective against development of AKI. Further experiments showed that exogenously delivered HDL does reduce oxidative stress, but only if the HDL were small particles. These particles cause downstream inactivation of inflammatory molecules, such as TNF-alpha, IL-6, and toll-like receptors, suggesting HDL particles reduce both oxidate stress and reduce inflammatory burden.

Michael Devinney, Jr., MD, PhD, Assistant Professor of Anesthesiology at Duke University, provided an update on the SANDMAN study, examining the role of obstructive sleep apnea in development of postoperative cognitive dysfunction. With the hypothesis being that sleep apnea leads to a chronic neuroinflammatory state, Dr. Devinney has almost completed enrollment in his trial, which will examine the relationship between cerebrospinal fluid cytokines, obstructive sleep apnea, and development of postoperative cognitive dysfunction.

Brittney Williams, MD, Assistant Professor of Anesthesiology at the University of Maryland, is studying the role of toll-like receptor 7 (TLR7) on platelet activation and coagulopathy in sepsis. Utilizing a TLR7 knock-out mouse model, Dr. Williams was able to show that TLR7 induces platelet activation and formation of platelet aggregates in a sepsis, which likely leads to thrombocytopenia and coagulopathy.

Mitra Heshmati, MD, PhD, Resident Physician in the Department of Anesthesiology at University of Washington, presented her research on neural circuits that are pertinent to the emergence state, especially in emergence delirium. Giving a background that shows the ventral tegmental area as important for arousal from sleep and anesthesia, she aimed to study how neurotransmitters are involved in the emergence sate. Using a murine model of arousal following general anesthesia, together with behavioral and optogenetics, Dr. Heshmati has shown that there is a significant dopaminergic release just prior to the righting reflex of mice, which would coincide with arousal and emergence from anesthesia.

Allison Janda, MD, Clinical Lecturer and Research Fellow in the Department of Anesthesiology at the University of Michigan, presented her work on utilizing large, multicenter databases to examine differences in practices and outcomes in cardiac surgical patients. Particularly examining the use of benzodiazepines, she showed a three-fold difference in benzodiazepine use due to practitioner difference and up to a five-fold difference in use due to institutional patterns.

James Khan, MD, FRCPC, Assistant Professor of Anesthesiology and Pain Medicine at the University of Toronto, discussed persistent pain following breast cancer surgery. Breast cancer surgery has the highest prevalence of persistent postsurgical pain at close to 40%. This obviously impacts the quality of life of the patient and costs $1 billion annually. Detailing results from the PLAN pilot trial, which uses intraoperative lidocaine infusion to hopefully reduce persistent postsurgical pain in breast cancer surgery, Dr. Kahn and colleagues have shown a 32% reduction in persistent postsurgical pain. Enrollment is still ongoing for the main trial.