Abstract/Description/Artist Statement
Introduction: Deep hypothermic circulatory arrest (DHCA) is utilized for neuroprotection during aortic surgery. The associations between the hemodynamic, metabolic and neurologic effects are not well characterized. We hypothesized that DHCA would be associated with hemodynamic and physiologic derangements which would correlate with neurological injury in a large animal model.
Methods: Twenty canines underwent 90 min DHCA at 18 °C with a randomized antegrade cerebral perfusion (ACP) flow rate (2.5, 5, or 10 cc/kg/min, n=6 for each) and were survived for 3 days. No ACP was implemented in controls (n=2). Intraoperative assessments included hemodynamic (mean arterial pressure (MAP) and heart rate (HR)) and laboratory values (pH, HCO3-, lactate, base excess (BE)). Neurologic testing was performed on postoperative days (POD) 1-3 with two validated, independent tests.
Results: There were significant differences in hemodynamics and acid-base balance in all canines before and after DHCA: HR increased from 97.8 to 135.7 bpm (p< 0.01), MAP increased 70.6 to 85.6 mmHg (p=0.01), lactate increased 2.1 to 6.3 mmol/L (p< 0.01), BE shifted -6.8 to -4.8 mEq/L (p=0.01), pH decreased 7.35 to 7.2 (p=0.040), and HCO3- increased 17.9 to 20.1 mEq/L (p=0.016). Importantly, BE and pH on POD1 and lactate on POD1 and 2 were significantly correlated with worse neurologic performance (p< 0.05) (Figure 1).
Conclusions: DHCA is associated with significant changes in hemodynamics and metabolic lab markers in canines despite variation in ACP flow rate. Uncompensated acidosis is associated with worse neurological function after DHCA. More research into the mechanisms and treatment of acidosis following DHCA is needed.
Faculty Advisor/Mentor
Jennifer Lawton
Faculty Advisor/Mentor Department
Department of Cardiac Surgery, Department of Surgery, Johns Hopkins School of Medicine
College/School Affiliation
Other
Student Level Group
Medical
Presentation Type
Poster
Included in
Acidosis During DHCA is associated with Neurologic Injury in a Canine Model
Introduction: Deep hypothermic circulatory arrest (DHCA) is utilized for neuroprotection during aortic surgery. The associations between the hemodynamic, metabolic and neurologic effects are not well characterized. We hypothesized that DHCA would be associated with hemodynamic and physiologic derangements which would correlate with neurological injury in a large animal model.
Methods: Twenty canines underwent 90 min DHCA at 18 °C with a randomized antegrade cerebral perfusion (ACP) flow rate (2.5, 5, or 10 cc/kg/min, n=6 for each) and were survived for 3 days. No ACP was implemented in controls (n=2). Intraoperative assessments included hemodynamic (mean arterial pressure (MAP) and heart rate (HR)) and laboratory values (pH, HCO3-, lactate, base excess (BE)). Neurologic testing was performed on postoperative days (POD) 1-3 with two validated, independent tests.
Results: There were significant differences in hemodynamics and acid-base balance in all canines before and after DHCA: HR increased from 97.8 to 135.7 bpm (p< 0.01), MAP increased 70.6 to 85.6 mmHg (p=0.01), lactate increased 2.1 to 6.3 mmol/L (p< 0.01), BE shifted -6.8 to -4.8 mEq/L (p=0.01), pH decreased 7.35 to 7.2 (p=0.040), and HCO3- increased 17.9 to 20.1 mEq/L (p=0.016). Importantly, BE and pH on POD1 and lactate on POD1 and 2 were significantly correlated with worse neurologic performance (p< 0.05) (Figure 1).
Conclusions: DHCA is associated with significant changes in hemodynamics and metabolic lab markers in canines despite variation in ACP flow rate. Uncompensated acidosis is associated with worse neurological function after DHCA. More research into the mechanisms and treatment of acidosis following DHCA is needed.