RESUMO
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.
Assuntos
Anestesia , Procedimentos Cirúrgicos Vasculares , Humanos , Procedimentos Cirúrgicos Vasculares/métodos , Anestesia/métodosRESUMO
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; ß = -0.037; p = 0.001 and proportion of perfused vessels: r = -0.17; ß = -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.
Assuntos
Ponte Cardiopulmonar , Ácido Láctico , Microcirculação , Mitocôndrias , Humanos , Microcirculação/fisiologia , Masculino , Estudos Prospectivos , Feminino , Ponte Cardiopulmonar/efeitos adversos , Ácido Láctico/sangue , Pessoa de Meia-Idade , Idoso , Mitocôndrias/metabolismo , Anaerobiose/fisiologia , Ácido Pirúvico/metabolismo , Ácido Pirúvico/sangueRESUMO
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/mm2, n = 20) or below (Low PVD = 15.5 ± 2.0 mm/mm2, 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.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Molécula 1 de Adesão Intercelular , Adulto , Humanos , Selectina E , Microcirculação , Molécula 1 de Adesão de Célula Vascular , Células Endoteliais , Procedimentos Cirúrgicos Cardíacos/efeitos adversosRESUMO
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/mm2, 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/mm2, 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/mm2, p < 0.009), PPV (90.76 vs. 95.91%, p < 0.001), PVD (20.44 vs. 26.41 mm/mm2, 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.
Assuntos
Nitroglicerina , Choque , Hemodinâmica/fisiologia , Humanos , Microcirculação/fisiologia , Microscopia de VídeoRESUMO
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.
Assuntos
Leucócitos Mononucleares , Choque , Hemodinâmica , Humanos , Microcirculação , Mitocôndrias , Estudos Observacionais como Assunto , Oxigênio , Estudos Prospectivos , Respiração , RessuscitaçãoRESUMO
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 2.0âmmol/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 6âh after surgery. Lactate area under the curve (AUC) was calculated over the first 6âh. The lactate AUC was compared between subjects with normal and low perfused vessel density (PVDâ<â18âmm/mm2), high microcirculatory heterogeneity index (MHIâ>â0.4), and low vessel-by-vessel microvascular flow index (MFIvâ<â2.6). 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]; Pâ<â0.0001). 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]; Pâ<â0.001). 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.
Assuntos
Acidose Láctica/fisiopatologia , Ponte Cardiopulmonar , Hemodinâmica , Microcirculação , Complicações Pós-Operatórias/fisiopatologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de TempoRESUMO
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/mm2) 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.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Ácido Láctico , Adulto , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Hemodinâmica , Humanos , Microcirculação , Soalho Bucal , Estudos ProspectivosAssuntos
Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Infecções por Coronavirus/complicações , Insuficiência Cardíaca/complicações , Hipertensão/complicações , Pneumonia Viral/complicações , Sistema Renina-Angiotensina/efeitos dos fármacos , Betacoronavirus , COVID-19 , Infecções por Coronavirus/fisiopatologia , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Hipertensão/tratamento farmacológico , Pandemias , Pneumonia Viral/fisiopatologia , Sistema Renina-Angiotensina/fisiologia , SARS-CoV-2RESUMO
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.
Assuntos
Anestesiologia , Bolsas de Estudo , Acreditação , Adulto , Anestesiologia/educação , Credenciamento , Educação de Pós-Graduação em Medicina , Humanos , Estados UnidosRESUMO
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.
Assuntos
Anestesiologia , Internato e Residência , Adulto , Anestesiologia/educação , Bolsas de Estudo , Humanos , Avaliação de Programas e Projetos de SaúdeAssuntos
Cateterismo Cardíaco/métodos , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/cirurgia , Instrumentos Cirúrgicos , Idoso de 80 Anos ou mais , Procedimentos Cirúrgicos Cardíacos/métodos , Implante de Prótese de Valva Cardíaca/métodos , Humanos , Masculino , Intervenção Coronária Percutânea/métodosRESUMO
Nephrologists use hemodialysis and hemofiltration to remove low molecular weight toxic constituents, and increasingly deploy therapeutic plasma exchange (TPE)/plasmapheresis to eliminate higher molecular weight substances such as immunoglobulins or immune complexes from plasma. This review discusses different modalities of TPE, their application in renal disorders, its rationale and complications. TPE is recommended based on evidence, in alloantibody-mediated diseases such as humoral antibody mediated renal transplant rejection, autoantibody mediated glomerulonephritis (GN) disorders for example, anti-glomerular basement membrane GN, as well as in antineutrophil cytoplasmic antibody mediated GN and antibody mediated thrombotic thrombocytopenic purpura. In many other renal illnesses, the rational use of TPE is gaining currency. Double membrane filtration, immune adsorption and cryofiltration are important modifications in TPE.
RESUMO
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.
Assuntos
Anestesia em Procedimentos Cardíacos , Anestesiologia/educação , Competência Clínica , Acreditação , Adulto , Viés , Bolsas de Estudo , HumanosAssuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Doenças Cardiovasculares/cirurgia , Circulação Cerebrovascular/fisiologia , Transtornos Cognitivos/diagnóstico , Monitorização Intraoperatória/métodos , Oximetria/métodos , Complicações Pós-Operatórias/diagnóstico , Adulto , Algoritmos , Doenças Cardiovasculares/metabolismo , Criança , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/metabolismo , Complicações Pós-Operatórias/metabolismo , Complicações Pós-Operatórias/fisiopatologiaRESUMO
Abnormal primary hemostasis is believed to be the most significant contributor to uremic bleeding. This study aimed to describe the prevalence and profile of primary and secondary hemostatic disorders in patients with chronic kidney disease (CKD) Stages 4 and 5 and to determine their association if any, with degree of uremia. Stages 4 and 5 predialysis CKD patients attending nephrology outpatient clinic were prospectively recruited and the following bleeding parameters were measured in all patients: platelet count, bleeding time (BT), Factor VIII assay, von Willebrand factor antigen (vWF:Ag), vWF:ristocetin cofactor activity (vWF:RCo), ratio of vWF:ristocetin cofactor activity to vWF antigen (vWF:RCo/vWF:Ag), prothrombin time (PT), and activated partial thromboplastin time (aPTT). Forty-five patients (80%, males) with a mean age of 39.4 years, 82% (n = 37) in Stage 5 CKD, were recruited for the study. The prevalence of thrombocytopenia was significantly higher among patients from West Bengal (15/26, 57.7%) compared to other study patients (2/19, 10.5%; P = 0.001); however, all had macrothrombocytes with normal BT, suggestive of the Harris syndrome. Factor VIII, vWF:Ag, vWF:RCo, vWF:RCo/vWF:Ag ratio, BT, PT, and aPTT were abnormal in 0 (0%), 0 (0%), 0 (0%), 4 (8.8%), 1 (2.2%), 7 (15.6%), and 5 (11.1%) patients, respectively. Except for thrombocytopenia, the prevalence of hemostatic abnormalities did not differ between CKD Stages 4 and 5. Hemostatic abnormalities are uncommon in Stages 4-5 CKD and except for thrombocytopenia, are not associated with degree of uremia. Constitutional macrothrombocytopenia is associated with normal BT even in CKD.