Shawn Kram, PharmD, BCPS, BCCCP (he/him/his)
Clinical Pharmacist, Cardiothoracic Surgery ICU
Duke University Hospital
Durham
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.jpg "Bridgette Kram, BCCCP, BCPS, PharmD photo")
Bridgette Kram, BCCCP, BCPS, PharmD
MICU Clinical Pharmacist
Duke University Hospital
Durham, North Carolina
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Jennifer Cook, PharmD
Clinical Pharmacist
Duke University Hospital
Durham, North Carolina, United States
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Kelsey Ohman, BCCCP, PharmD
Clinical Pharmacist
Duke University Hospital
Durham, North Carolina, United States
Disclosure information not submitted.
Kamrouz Ghadimi, MD, MHSc
Assoc. Professor, CT Anesthesiology & Critical Care
Duke University Hospital, United States
Disclosure information not submitted.
Title: Methylene Blue Dose-Response for Vasoplegic Syndrome in Adult Cardiothoracic Surgery
Introduction: Intravenous methylene blue is commonly administered by variable weight-based dosing strategies for vasoplegic syndrome in adult cardiothoracic surgery. The purpose of this study is to determine the optimal weight-based methylene blue dose that reduces vasopressor requirements in this critically ill population.
Methods: A retrospective, single-center cohort study was performed in adult cardiothoracic surgical patients undergoing cardiopulmonary bypass (CPB) who received methylene blue for vasoplegic syndrome during the index operation or in the ICU up to 24 hours after CPB separation between July 2013 and May 2020. Patients were excluded if administered hydroxocobalamin or additional methylene blue within 120 minutes after the initial dose of methylene blue. Response was measured by changes in vasopressor requirements using norepinephrine equivalents (NEE) immediately prior to and 120 minutes after methylene blue administration.
Results: Of the 390 patients screened, 120 were analyzed. The median age was 58 years (IQR 46-68), median weight was 89 kg (IQR 73-103), and median methylene blue dose was 1.2 mg/kg (IQR 0.9-2.0). The most common operations were coronary artery bypass graft (n=27) and aortic valve replacement (n=26). After adjusting for prespecified clinical covariates associated with vasoplegic syndrome, a significant relationship was detected between the first methylene blue dose and response by reduction in NEE. The minimum methylene blue dose for any reduction in NEE was 1.4 mg/kg. For each incremental dose increase of 0.5 mg/kg, a 57.4% (95% CI 49.1-65.7, p< 0.001) decrease in NEE was observed up to 2.25 mg/kg.
Conclusions: In adult cardiothoracic surgical patients with perioperative vasoplegic syndrome, a methylene blue dose-response relationship between 1.4 to 2.25 mg/kg was observed. Larger cohorts and different critically ill populations are needed to validate these specific dose-response findings.