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Objectives: Quantify the relationship between perioperative anaerobic lactate production, microcirculatory blood flow, and mitochondrial respiration in patients after cardiovascular surgery with cardiopulmonary bypass., Design: Serial measurements of lactate-pyruvate ratio (LPR), microcirculatory blood flow, plasma tricarboxylic acid cycle cycle intermediates, and mitochondrial respiration were compared between patients with a normal peak lactate (≤ 2 mmol/L) and a high peak lactate (≥ 4 mmol/L) in the first 6 hours after surgery. Regression analysis was performed to quantify the relationship between clinically relevant hemodynamic variables, lactate, LPR, and microcirculatory blood flow., Setting: This was a single-center, prospective observational study conducted in an academic cardiovascular ICU., Patients: One hundred thirty-two patients undergoing elective cardiovascular surgery with cardiopulmonary bypass., Interventions: None., Measurements and Main Results: Patients with a high postoperative lactate were found to have a higher LPR compared with patients with a normal postoperative lactate (14.4 ± 2.5 vs. 11.7 ± 3.4; p = 0.005). Linear regression analysis found a significant, negative relationship between LPR and microcirculatory flow index ( r = -0.225; β = -0.037; p = 0.001 and proportion of perfused vessels: r = -0.17; β = -0.468; p = 0.009). There was not a significant relationship between absolute plasma lactate and microcirculation variables. Last, mitochondrial complex I and complex II oxidative phosphorylation were reduced in patients with high postoperative lactate levels compared with patients with normal lactate (22.6 ± 6.2 vs. 14.5 ± 7.4 pmol O 2 /s/10 6 cells; p = 0.002)., Conclusions: Increased anaerobic lactate production, estimated by LPR, has a negative relationship with microcirculatory blood flow after cardiovascular surgery. This relationship does not persist when measuring lactate alone. In addition, decreased mitochondrial respiration is associated with increased lactate after cardiovascular surgery. These findings suggest that high lactate levels after cardiovascular surgery, even in the setting of normal hemodynamics, are not simply a type B phenomenon as previously suggested., Competing Interests: Drs. Greenwood, Jang, and Brenner received support for article research from the National Institutes of Health. Dr. Greenwood is supported by the National Center for Advancing Translational Sciences (award number KL2TR001879). Dr. Jang is supported by the National Heart, Lung, and Blood Institute (NHLBI; award number R01HL166592). Dr. Acker received funding from FineHeart. Dr. Kilbaugh is supported by the National Institutes of Congenital Heart Disease (award number R01HL141386). Dr. Brenner is supported by the NHLBI (award number R01HL153510). Dr. Brenner’s institution received funding from BioNTech, AltruMed, and Code BioTherapeutics. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2024 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

The authors thank the editors for this opportunity to review the recent literature on vascular surgery and anesthesia and provide this clinical update. The last in a series of updates on this topic was published in 2019. 1 This review explores evolving discussions and current trends related to vascular surgery and anesthesia that have been published since then. The focus is on the major points discussed in the recent literature in the following areas: carotid artery surgery, infrarenal aortic surgery, peripheral vascular surgery, and the preoperative evaluation of vascular surgical patients., Competing Interests: Declaration of competing interest M.W.V. has received royalties from the Dana-Farber Cancer Institute/Novartis for a novel cancer immunotherapy in clinical development. R.J. F. has received travel support from Abbott for MitraClip training. The other authors have nothing to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Introduction: Microcirculatory dysfunction after cardiovascular surgery is associated with significant morbidity and worse clinical outcomes. Abnormal capillary blood flow can occur from multiple causes, including cytokine-mediated vascular endothelial injury, microthrombosis, and an inadequate balance between vasoconstriction and vasodilation. In response to proinflammatory cytokines, endothelial cells produce cellular adhesion molecules (CAMs) which regulate leukocyte adhesion, vascular permeability, and thus can mediate tissue injury. The relationship between changes in microcirculatory flow during circulatory shock and circulating adhesion molecules is unclear. The objective of this study was to compare changes in plasma soluble endothelial cell adhesion molecules (VCAM-1, ICAM-1, and E-Selectin) in patients with functional derangements in microcirculatory blood flow after cardiovascular surgery., Methods: Adult patients undergoing elective cardiac surgery requiring cardiopulmonary bypass who exhibited postoperative shock were enrolled in the study. Sublingual microcirculation imaging was performed prior to surgery and within 2 h of ICU admission. Blood samples were taken at the time of microcirculation imaging for biomarker analysis. Plasma soluble VCAM-1, ICAM-1, and E-selectin in addition to plasma cytokines (IL-6, IL-8, and IL-10) were measured by commercially available enzyme-linked immunoassay., Results: Of 83 patients with postoperative shock who were evaluated, 40 patients with clinical shock had a postoperative perfused vessel density (PVD) >1 SD above (High PVD group = 28.5 ± 2.3 mm/mm 2 , n = 20) or below (Low PVD = 15.5 ± 2.0 mm/mm 2 , n = 20) the mean postoperative PVD and were included in the final analysis. Patient groups were well matched for comorbidities, surgical, and postoperative details. Overall, there was an increase in postoperative plasma VCAM-1 and E-Selectin compared to preoperative levels, but there was no difference between circulating ICAM-1. When grouped by postoperative microcirculation, patients with poor microcirculation were found to have increased circulating VCAM-1 (2413 ± 1144 vs. 844 ± 786 ng/mL; p < 0.0001) and E-Selectin (242 ± 119 vs. 87 ± 86 ng/mL; p < 0.0001) compared to patients with increased microcirculatory blood flow. Microcirculatory flow was not associated with a difference in plasma soluble ICAM-1 (394 ± 190 vs. 441 ± 256; p = 0.52)., Conclusions: Poor postoperative microcirculatory blood flow in patients with circulatory shock after cardiac surgery is associated with increased plasma soluble VCAM-1 and E-Selectin, indicating increased endothelial injury and activation compared to patients with a high postoperative microcirculatory blood flow. Circulating endothelial cell adhesion molecules may be a useful plasma biomarker to identify abnormal microcirculatory blood flow in patients with shock., Competing Interests: Declaration of competing interest None. None of the authors have received any financial support or have a conflict of interest related to Cytocam or Braedius, BV., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Persistent abnormalities in microcirculatory function are associated with poor clinical outcomes in patients with circulatory shock. We sought to identify patients with acutely reversible microcirculatory dysfunction using a low-dose topical nitroglycerin solution and handheld videomicroscopy during circulatory shock after cardiac surgery. Forty subjects were enrolled for the study, including 20 preoperative control and 20 post-operative patients with shock. To test whether microcirculatory dysfunction is acutely reversible during shock, the sublingual microcirculation was imaged with incident dark field microscopy before and after the application of 0.1 mL of a 1% nitroglycerin solution (1 mg/mL). Compared to the control group, patients with shock had a higher microcirculation heterogeneity index (MHI 0.33 vs. 0.12, p < 0.001) and a lower microvascular flow index (MFI 2.57 vs. 2.91, p < 0.001), total vessel density (TVD 22.47 vs. 25.90 mm/mm 2 , p = 0.005), proportion of perfused vessels (PPV 90.76 vs. 95.89%, p < 0.001) and perfused vessel density (PVD 20.44 vs. 24.81 mm/mm 2 , p < 0.001). After the nitroglycerin challenge, patients with shock had an increase in MFI (2.57 vs. 2.97, p < 0.001), TVD (22.47 vs. 27.51 mm/mm 2 , p < 0.009), PPV (90.76 vs. 95.91%, p < 0.001), PVD (20.44 vs. 26.41 mm/mm 2 , p < 0.001), venular RBC velocity (402.2 vs. 693.9 µm/s, p < 0.0004), and a decrease in MHI (0.33 vs. 0.04, p < 0.001. Thirteen of 20 patients showed a pharmacodynamic response, defined as an increase in PVD > 1.8 SD from shock baseline. Hemodynamics and vasoactive doses did not change during the 30-min study period. Our findings suggest a topical nitroglycerin challenge with handheld videomicroscopy can safely assess for localized recruitment of the microcirculatory blood flow in patients with circulatory shock and may be a useful test to identify nitroglycerin responsiveness., (© 2022. The Author(s).)

Background: Despite current resuscitation strategies, circulatory shock and organ injury after cardiac surgery occur in 25-40% of patients. Goal-directed resuscitation after cardiac surgery has generated significant interest, but clinical practice to normalize hemodynamic variables including mean arterial pressure, cardiac filling pressures, and cardiac output may not reverse microcirculation abnormalities and do not address cellular dysoxia. Recent advances in technology have made it possible to measure critical components of oxygen delivery and oxygen utilization systems in live human tissues and blood cells. The MicroRESUS study will be the first study to measure microcirculatory and mitochondrial function in patients with circulatory shock and link these findings with clinical outcomes., Methods and Analysis: This will be a prospective, observational study that includes patients undergoing elective cardiovascular surgery with cardiopulmonary bypass (CPB). Microcirculation will be quantified with sublingual incident dark field videomicroscopy. Mitochondrial respiration will be measured by performing a substrate-uncoupler-inhibitor titration protocol with high resolution respirometry on peripheral blood mononuclear cells at baseline and serial timepoints during resuscitation and at recovery as a possible liquid biomarker. Plasma samples will be preserved for future analysis to examine endothelial injury and other mechanisms of microcirculatory dysfunction. Thirty-day ventilator and vasopressor-free days (VVFDs) will be measured as a primary outcome, along with sequential organ failure assessment scores, and other clinical parameters to determine if changes in microcirculation and mitochondrial respiration are more strongly associated with clinical outcomes compared to traditional resuscitation targets., Discussion: This will be the first prospective study to examine both microcirculatory and mitochondrial function in human patients with circulatory shock undergoing cardiac bypass and address a key mechanistic knowledge gap in the cardiovascular literature. The results of this study will direct future research efforts and therapeutic development for patients with shock., Competing Interests: The authors have declared that no competing interests exist.

Introduction: Lactic acidosis after cardiac surgery with cardiopulmonary bypass is common and associated with an increase in postoperative morbidity and mortality. A number of potential causes for an elevated lactate after cardiopulmonary bypass include cellular hypoxia, impaired tissue perfusion, ischemic-reperfusion injury, aerobic glycolysis, catecholamine infusions, and systemic inflammatory response after exposure to the artificial cardiopulmonary bypass circuit. Our goal was to examine the relationship between early abnormalities in microcirculatory convective blood flow and diffusive capacity and lactate kinetics during early resuscitation in the intensive care unit. We hypothesized that patients with impaired microcirculation after cardiac surgery would have a more severe postoperative hyperlactatemia, represented by the lactate time-integral of an arterial blood lactate concentration greater than 2.0 mmol/L., Methods: We measured sublingual microcirculation using incident darkfield video microscopy in 50 subjects on intensive care unit admission after cardiac surgery. Serial measurements of systemic hemodynamics, blood gas, lactate, and catecholamine infusions were recorded each hour for the first 6 h after surgery. Lactate area under the curve (AUC) was calculated over the first 6 h. The lactate AUC was compared between subjects with normal and low perfused vessel density (PVD < 18 mm/mm2), high microcirculatory heterogeneity index (MHI > 0.4), and low vessel-by-vessel microvascular flow index (MFIv < 2.6)., Results: Thirteen (26%) patients had a low postoperative PVD, 20 patients (40%) had a high MHI, and 26 (52%) patients had a low MFIv. Patients with low perfused vessel density had higher lactate AUC compared with subjects with a normal PVD (22.3 [9.4-31.0] vs. 2.6 [0-8.8]; P < 0.0001). Patients with high microcirculatory heterogeneity had a higher lactate AUC compared with those with a normal MHI (2.5 [0.1-8.2] vs. 13.1 [3.7-31.1]; P < 0.001). We did not find a difference in lactate AUC when comparing high and low MFIv., Conclusion: Low perfused vessel density and high microcirculatory heterogeneity are associated with an increased intensity and duration of lactic acidosis after cardiac surgery with cardiopulmonary bypass., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by the Shock Society.)

Objective: Resuscitation after cardiac surgery needs to address multiple pathophysiological processes that are associated with significant morbidity and mortality. Functional microcirculatory derangements despite normal systemic hemodynamics have been previously described but must be tied to clinical outcomes. The authors hypothesized that microcirculatory dysfunction after cardiac surgery would include impaired capillary blood flow and impaired diffusive capacity and that subjects with the lowest quartile of perfused vessel density would have an increased postoperative lactate level and acute organ injury scores., Design: Prospective, observational study., Setting: A single, tertiary university cardiovascular surgical intensive care unit., Participants: 25 adults undergoing elective cardiac surgery requiring cardiopulmonary bypass., Intervention: Sublingual microcirculation was imaged using incident dark field microscopy before and 2 to 4 hours after surgery in the intensive care unit., Measurements and Main Results: Compared with baseline measurements, postoperative vessel-by-vessel microvascular flow index (2.9 [2.8-2.9] v 2.5 [2.4-2.7], p < 0.0001) and perfused vessel density were significantly impaired (20.7 [19.3-22.9] v 16.3 [12.8-17.9], p < 0.0001). The lowest quartile of perfused vessel density (<12.8 mm/mm 2 ) was associated with a significantly increased postoperative lactate level (6.0 ± 2.9 v 1.8 ± 1.2, p < 0.05), peak lactate level (7.6 ± 2.8 v 2.8 ± 1.5, p = 0.03), and sequential organ failure assessment (SOFA) score at 24 and 48 hours., Conclusion: In patients undergoing cardiac surgery, there was a significant decrease in postoperative microcirculatory convective blood flow and diffusive capacity during early postoperative resuscitation. Severely impaired perfused vessel density, represented by the lowest quartile of distribution, is significantly related to hyperlactatemia and early organ injury., Competing Interests: Conflict of Interest None. None of the authors has received any financial support or has a conflict of interest related to Cytocam or Braedius, BV., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The fellowship in adult cardiothoracic anesthesiology has matured as an accredited program. This special article addresses current challenges in this educational milieu. The first challenge relates to serving as a program director in the contemporary era. The second challenge deals with the accreditation process, including the site visit. The third challenge discusses the integration of structural heart disease and interventional echocardiography into daily practice. The fourth challenge deals with the issues that face fellowship education in the near future. Taken together, these perspectives provide a review of the contemporary challenges facing fellowship education in adult cardiothoracic anesthesiology., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The Program Evaluation Committee has an essential role in the quality improvement process of the adult cardiothoracic anesthesiology fellowship. The annual program evaluation presents all stakeholders with an opportunity to evolve with the changing needs and opportunities of the fellowship milieu. The active engagement of the program in this process is a high-quality approach to successful planning, preparation and conduct of the self-study and site visit that are important extensions of the annual program evaluation and the program evaluation committee., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to disclose., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The clinical competency committee offers a fellowship program a structured approach to assess the clinical performance of each trainee in a comprehensive fashion This special article examines the structure and function of this important committee in detail. Furthermore, the strategies for the optimal functioning of this committee are also discussed as a way to enhance the overall quality of the fellowship program., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Vasoplegic syndrome, characterized by low systemic vascular resistance and hypotension in the presence of normal or supranormal cardiac function, is a frequent complication of cardiovascular surgery. It is associated with a diffuse systemic inflammatory response and is mediated largely through cellular hyperpolarization, high levels of inducible nitric oxide, and a relative vasopressin deficiency. Cardiopulmonary bypass is a particularly strong precipitant of the vasoplegic syndrome, largely due to its association with nitric oxide production and severe vasopressin deficiency. Postoperative vasoplegic shock generally is managed with vasopressors, of which catecholamines are the traditional agents of choice. Norepinephrine is considered to be the first-line agent and may have a mortality benefit over other drugs. Recent investigations support the use of noncatecholamine vasopressors, vasopressin in particular, to restore vascular tone. Alternative agents, including methylene blue, hydroxocobalamin, corticosteroids, and angiotensin II, also are capable of restoring vascular tone and improving vasoplegia, but their effect on patient outcomes is unclear., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The functional aortic annulus offers a clinical approach for the perioperative echocardiographer to classify the mechanisms of aortic regurgitation in acute type-A dissection. Comprehensive examination of the functional aortic annulus in this setting using transesophageal echocardiography can guide surgical therapy for the aortic root by considering the following important aspects: severity and mechanism of aortic regurgitation, extent of root dissection, and the pattern of coronary artery involvement. The final choice of surgical therapy also should take into account factors, such as patient presentation and surgical experience, to limit mortality and morbidity from this challenging acute aortic syndrome. This review explores these concepts in detail within the framework of the functional aortic annulus, detailed anatomic considerations, and the latest literature., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objectives: Diversity in the physician workforce is essential to providing culturally effective care. In critical care, despite the high stakes and frequency with which cultural concerns arise, it is unknown whether physician diversity reflects that of critically ill patients. We sought to characterize demographic trends in critical care fellows, who represent the emerging intensivist workforce., Design: We used published data to create logistic regression models comparing annual trends in the representation of women and racial/ethnic groups across critical care fellowship types., Setting: United States Accreditation Council on Graduate Medical Education-approved residency and fellowship training programs., Subjects: Residents and fellows employed by Accreditation Council on Graduate Medical Education-accredited training programs from 2004 to 2014., Interventions: None., Measurements and Main Results: From 2004 to 2014, the number of critical care fellows increased annually, up 54.1% from 1,606 in 2004-2005 to 2,475 in 2013-2014. The proportion of female critical care fellows increased from 29.5% (2004-2005) to 38.3% (2013-2014) (p < 0.001). The absolute number of black fellows increased each year but the percentage change was not statistically significantly different (5.1% in 2004-2005 vs 3.9% in 2013-2014; p = 0.92). Hispanic fellows increased in number from 124 (7.7%) in 2004-2005 to 216 (8.4%) in 2013-2014 (p = 0.015). The number of American Indian/Alaskan Native/Native Hawaiian/Pacific Islander fellows decreased from 15 (1.0%) to seven (0.3%) (p < 0.001). When compared with population estimates, female critical care fellows and those from racial/ethnic minorities were underrepresented in all years., Conclusions: The demographics of the emerging critical care physician workforce reflect underrepresentation of women and racial/ethnic minorities. Trends highlight increases in women and Hispanics and stable or decreasing representation of non-Hispanic underrepresented minority critical care fellows. Further research is needed to elucidate the reasons underlying persistent underrepresentation of racial and ethnic minorities in critical care fellowship programs.

This article reviewed selected research highlights of 2013 that pertain to the specialty of cardiothoracic and vascular anesthesia. The first major theme is the commemoration of the sixtieth anniversary of the first successful cardiac surgical procedure with cardiopulmonary bypass conducted by Dr Gibbon. This major milestone revolutionized the practice of cardiovascular surgery and invigorated a paradigm of mechanical platforms for contemporary perioperative cardiovascular practice. Dr Kolff was also a leading contributor in this area because of his important contributions to the refinement of cardiopulmonary bypass and mechanical ventricular assistance. The second major theme is the diffusion of echocardiography throughout perioperative practice. There are now guidelines and training pathways to guide its generalization into everyday practice. The third major theme is the paradigm shift in perioperative fluid management. Recent large randomized trials suggest that fluids are drugs that require a precise prescription with respect to type, dose, and duration. The final theme is patient safety in the cardiac perioperative environment. A recent expert scientific statement has focused attention on this issue because most perioperative errors are preventable. It is likely that clinical research in this area will blossom because this is a major opportunity for improvement in our specialty. The patient care processes identified in these research highlights will further improve perioperative outcomes for our patients., (© 2013 Elsevier Inc. All rights reserved.)

Incidental moderate mitral regurgitation (MR) in patients presenting for coronary artery bypass grafting (CABG) is not only common but also probably adversely affects clinical outcome. The echocardiographic evaluation of incidental MR must be comprehensive and integrated, as it remains a cornerstone in management decisions. Current guidelines support surgical mitral intervention in this setting as a reasonable option, reflecting clinical equipoise towards moderate MR in the setting of planned CABG. There are currently 2 major randomized trials in progress that will test whether surgical correction of moderate MR combined with CABG improves major clinical outcomes as compared to CABG alone. These landmark trials will be completed in the near future. In the interim, significant progress in the fields of cardiac resynchronization therapy, transcatheter mitral valve intervention, and minimally invasive mitral valve surgery promise to affect the management alternatives for moderate MR in patients undergoing CABG regardless of operative risk. It is likely that in the coming decade there will be less tolerance for incidental moderate MR given its already known outcome effects and the multimodal interventions that continue to mature with better safety profiles., (Copyright © 2014. Published by Elsevier Inc.)