Simon Mölström1, Troels H Nielsen2, Claus Andersen3, Carl H Nordström2, Palle Toft4. 1. Department of Anesthesiology and Intensive Care, Odense University Hospital, Odense, Denmark. Electronic address: Smolstrom@gmail.com. 2. Department of Neurosurgery, Odense University Hospital, Odense, Denmark. 3. Department of Anesthesiology and Intensive Care, Thorax Anesthesiology Unit VITA, Odense University Hospital, Odense, Denmark. 4. Department of Anesthesiology and Intensive Care, Odense University Hospital, Odense, Denmark.
Abstract
OBJECTIVES: This study investigated whether the lactate-to-pyruvate (LP) ratio obtained by microdialysis (MD) of the cerebral venous outflow reflected a derangement of global cerebral energy state during cardiopulmonary bypass (CPB). DESIGN: Interventional, prospective, randomized study. SETTING: Single-center, university teaching hospital. PARTICIPANTS: The study included 10 patients undergoing primary, elective coronary artery bypass grafting. INTERVENTIONS: Patients were randomized blindly to low mean arterial pressure (MAP) (40-60 mmHg; n = 5) or high MAP (60-80 mmHg; n = 5) during CPB. The MD catheters were positioned in a retrograde direction into the jugular bulb, and a reference catheter was inserted into the brachial artery. The correlations among LP ratio, MAP, data obtained from bifrontal near-infrared spectroscopy (NIRS), and postoperative neurologic outcome measures were assessed. MEASUREMENTS AND MAIN RESULTS: The correlated difference between pooled LP ratio (low and high MAP) of the jugular venous and the arterial blood was significant (LParterial 17 [15-20] v LPvenous 26 [23-27]; p = 0.0001). No cerebral desaturations (decrease in rSO2>20% from baseline) were observed in either group during CPB. In each group, 50% of the patients showed significant cognitive decline (mini-mental state examination, 3 points) 2 days after surgery. CONCLUSION: The LP ratio of cerebral venous blood increased significantly during CPB, indicating compromised cerebral oxidative metabolism. Conventional monitoring of rSO2 by NIRS did not show a corresponding decrease in cerebral oxygenation. As the patients exhibited decreased cognitive functions after CPB, increases in jugular venous LP ratio may be a sensitive indicator of impending cerebral damage.
RCT Entities:
OBJECTIVES: This study investigated whether the lactate-to-pyruvate (LP) ratio obtained by microdialysis (MD) of the cerebral venous outflow reflected a derangement of global cerebral energy state during cardiopulmonary bypass (CPB). DESIGN: Interventional, prospective, randomized study. SETTING: Single-center, university teaching hospital. PARTICIPANTS: The study included 10 patients undergoing primary, elective coronary artery bypass grafting. INTERVENTIONS:Patients were randomized blindly to low mean arterial pressure (MAP) (40-60 mmHg; n = 5) or high MAP (60-80 mmHg; n = 5) during CPB. The MD catheters were positioned in a retrograde direction into the jugular bulb, and a reference catheter was inserted into the brachial artery. The correlations among LP ratio, MAP, data obtained from bifrontal near-infrared spectroscopy (NIRS), and postoperative neurologic outcome measures were assessed. MEASUREMENTS AND MAIN RESULTS: The correlated difference between pooled LP ratio (low and high MAP) of the jugular venous and the arterial blood was significant (LParterial 17 [15-20] v LPvenous 26 [23-27]; p = 0.0001). No cerebral desaturations (decrease in rSO2>20% from baseline) were observed in either group during CPB. In each group, 50% of the patients showed significant cognitive decline (mini-mental state examination, 3 points) 2 days after surgery. CONCLUSION: The LP ratio of cerebral venous blood increased significantly during CPB, indicating compromised cerebral oxidative metabolism. Conventional monitoring of rSO2 by NIRS did not show a corresponding decrease in cerebral oxygenation. As the patients exhibited decreased cognitive functions after CPB, increases in jugular venous LP ratio may be a sensitive indicator of impending cerebral damage.
Authors: Simon Mölström; Troels Halfeld Nielsen; Carl H Nordström; Christian Hassager; Jacob Eifer Møller; Jesper Kjærgaard; Sören Möller; Henrik Schmidt; Palle Toft Journal: Trials Date: 2019-06-10 Impact factor: 2.279