2010 MSARF Symposium Participants - Foundation for Anesthesia ...

dehydration of the intravascular space. Recognizing how the presence of glycosuria affects urine volume and composition
in surgical patients is important for preemptively managing fluids and insulin for the best clinical outcomes.
Student Name: Albert Tsai
Host Department: University of Pennsylvania School of Medicine
Primary Mentor Name: Max Kelz, MD, PhD
Title of Research Project: Disruption of Circadian Rhythms Following Extended Exposure to Isoflurane in
Drosophila
Background: Circadian rhythms are fundamental to all eukaryotes and can be characterized by a neuronal circuit
consisting of input, core clock, and output components. Given that anesthetics disrupt synaptic signaling, it is not
surprising recent studies suggest anesthetics might affect circadian rhythms. However, the mechanisms through which this
occur remain unknown. Using Drospohila we investigate the effects of volatile anesthetics upon circadian functioning.
Methods: Flies were entrained on a 12-h light/12-h dark schedule and subsequently placed into constant darkness. 1.2%
isoflurane was delivered for 2 or 6 hours at different circadian times to determine anesthetic effects on a circadian
output—locomotor behavior. Separately, light pulses were given during 2-hour isoflurane exposures to determine if the
clock remained responsive to inputs. Finally, isoflurane and halothane were applied directly to cultured cell reporter
system to determine the effects upon the core clock.
Results: During a 2-hour 1.2% isoflurane anesthetic, input, output, and core circadian clock functions remained
unaffected. Core clock function was also unaffected by 1.0% halothane. However, output of the clock was significantly
shifted by a 6-hour 1.2% isoflurane exposure, yielding phase shifts ranging from -43 minutes to +75 minutes, with no
effect on the circadian period.
Conclusions: These results suggest normal circadian functioning following acute exposures to volatile anesthetics.
However, following prolonged exposure to isoflurane, circadian disturbances arise, which may be attributable to
accumulation of homeostatic drive and its interaction with the circadian process. Clinically, this might suggest a dosedependent
effect of general anesthetics on circadian rhythm disruptions following surgery.
Student Name: Ajayram Ullal
Host Department: Montefiore Medical Center The University Hospital for the Albert Einstein College of Medicine
Primary Mentor Name: Linda Shore-Lesserson, MD
Additional Mentors: Elise Delphin, MD
Title of Research Project: A randomized, double-blinded trial comparing the efficacy of tranexamic acid and
epsilon-aminocaproic acid in reducing bleeding and transfusion in cardiac surgery.
Background: Patients who undergo cardiopulmonary bypass (CPB) for cardiac surgery are at high risk for post-operative
bleeding. Without aprotinin available, two lysine-analogues, tranexamic Acid (TA) and epsilon-aminocaproic acid
(EACA) have become the standard of care to control bleeding following CPB. The purpose of this study is to compare
TA to EACA in reducing bleeding and transfusion requirements following CPB.
Methods: This is a single-center, randomized, double-blind trial targeted to enroll 196 adult patients undergoing cardiac
surgery involving CPB. Patients randomly receive prophylactic EACA or TA at standard dose. Blood is sampled at
baseline, after loading dose, and post-protamine for ROTEM®, Thromboelastography (TEG), and D-Dimer analyses.
Chest tube drainage(CTD) and transfusions are followed for 24 hours, and complications assessed up to 30 days.
Results: Blinded interim analysis after 81 patients reveals no statistically significant differences between groups in CTD,
transfusion volumes, TEG/ROTEM parameters, or complications. One group, did have a non-statistically significant
trend towards a lower transfusion rate (p