Introdução: Prever a capacidade de resposta a fluidos continua sendo um desafio para os médicos que lidam com pacientes instáveis hemodinamicamente. A utilização de parâmetros estáticos, como pressão venosa central (PVC) tem sido usada por décadas, mas não é confiável, evidências robustas sugerem que seu uso deve ser abandonado. Ao longo dos últimos 15 anos, foram desenvolvidos vários testes dinâmicos, baseados no princípio de alteração da pré-carga cardíaca, usando as interações coração-pulmão, e, consequentemente do débito cardíaco. A elevação passiva das pernas (EPP), a infusão de pequenos volumes de fluidos, a variação da pressão de pulso (ΔPP), as variações nos diâmetros de grandes veias tem sido muito utilizados para avaliação de fluidoresponsividade (FR), neste contexto. Objetivo: Analisar e comparar medidas estáticas e dinâmicas antes, após EPP e após infusão de SF, verificando qual delas apresentam melhor FR. Métodos: Trinta e um pacientes instáveis hemodinamicamente e sob ventilação mecânica (VM) foram incluídos no estudo. Foram avaliados VTIFAO, VTIFMi, IDVCI, ΔPP, PVC, PAM antes de qualquer intervenção, após EPP e após infusão de 500ml SF. As variações dos parâmetros foram calculados para todos os pacientes. Resultados: Após EPP e infusão de SF o VTIFAO aumentou em 10% ou mais em 14 (45%) e 18 (58%) pacientes respectivamente, definidos como FR. A EPP previu a capacidade de resposta a fluidos com uma sensibilidade de 77,7%, especificidade de 100%, valor preditivo positivo de 100% e probabilidade de falso positivo de 0%. O parâmetro utilizado como padrão para FR foi o VTIFAO após SF. A PVC, o IDVCI, o ΔPP, PAM e avaliação médica não se mostraram capazes de avaliar adequadamente FR. Conclusão: Em pacientes instáveis hemodinamicamente e sob VM, a EPP foi capaz de avaliar FR com adequada sensibilidade e especificidade, podendo ser usada com segurança, antes da administração de fluidos. / Introduction: Predictig fluid responsiveness remains a constant challenge for physicians dealing with hemodynamically unstable patients. The use of static parameters, such as central venous pressure (CVP), although used for decades is not a trustworthy source, and the suggestion derived from more robust evidence suggests that the use of such should be abandoned. Over the last 15 years, various dynamic tests have been developed based on the principle of altering the cardiac preload, by using the heart-lung interactions and consequently cardiac output. Hence, Passive Leg Raising (PLR), the intake of small amounts of fluid, the variation of pulse pressure, variations in the diameter of large veins have all been widely used for evaluating fluid responsiveness (FR), within this context. Objective: The underlying objective behind this study was to test, if the non-invasive evaluation with transthoracic echocardiography, the Subaortic velocity time integral (VTI), the Distensibility Index of the Inferior Vena Cava (dIVC), the mitral velocity time integral (MTI), the (CVP) and the change in pulse pressure (ΔPP) after (PLR) and fluid infusion (500ml of saline solution) are able to predict the responsiveness of fluid therapy. Methods: Thirty one hemodynamically unstable patients, under mechanical ventilation (MV) were included in the study. Evaluations were made of VTI, MTI, DIVC), ΔPP and CVP before any intervention, after PLR and after infusion of 500ml saline solution. The variations of the parameters were calculated for all patients. Results: After PLR and infusion of saline solution, the VTI increased by 10% or more in 14 (45%) and 18 (58%) patients, respectively, defined as fluid responders. The PLR predicted a response capacity to fluids with a sensibility of 77,7%, specificity of 100%, a positive predictive value of 100% and a false positive probability of 0%. The CVP, dIVC, ΔPP, PAM and the medical evaluation were not capable of providing an adequate FR evaluation. Conclusion: In hemodynamically unstable patients under MV, PLR were capable of precisely predicting the capacity of FR. / Dissertação (Mestrado)

Introdução: A fluidoterapia é o tratamento de primeira linha para pacientes em choque hemorrágico ou choque séptico para restauração do volume circulante e da perfusão tecidual, mas diversas questões relacionadas a este tópico permanecem em debate, particularmente em relação às metas de ressuscitação representadas por variáveis fisiológicas a serem atingidas. A variação de pressão de pulso (VPP) já foi proposta como índice confiável para predição de fluido-responsividade em pacientes sob ventilação mecânica, mas requer avaliação complementar em variadas condições fisiopatológicas. Objetivo: O propósito do presente estudo foi comparar, em um modelo experimental de choque hemorrágico agudo com endotoxemia, uma estratégia de ressuscitação volêmica aguda guiada por VPP e pressão arterial média (PAM) a outra baseada em metas de ressuscitação convencionalmente empregadas envolvendo pressão venosa central (PVC), PAM e saturação venosa mista de oxigênio (SvO2). O modelo experimental foi desenvolvido para esta finalidade e cada variável empregada como meta foi adicionalmente avaliada quanto à capacidade de predição de fluido-responsividade. Métodos: Cinquenta e um porcos foram anestesiados, mecanicamente ventilados e, após preparo, aleatoriamente divididos em seis grupos: controle (Sham, n=8); infusão intravenosa de endotoxina em doses decrescentes (LPS, n=8); choque hemorrágico obtido por meio da retirada de 50% da volemia estimada em 20 minutos (Hemo, n=8); choque hemorrágico com endotoxemia conforme protocolos dos grupos LPS e Hemo (Hemo+LPS, n=9); choque hemorrágico com endotoxemia e, após 60 minutos, ressuscitação com cristalóides para atingir metas: PVC 12-15 mmHg, PAM ≥ 65 mmHg e SvO2 ≥ 65% (Conv, n=9); choque hemorrágico com endotoxemia e, após 60 minutos, ressuscitação com cristalóides para atingir as metas VPP ≤ 13% e PAM ≥ 65 mmHg (dPP, n=9). Tratamentos foram realizados por três horas. Além da avaliação hemodinâmica incluindo termodiluição e ecocardiografia transesofágica, foram realizadas gasometria arterial com mensuração de eletrólitos e lactato, gasometria venosa mista e tonometria intestinal. Ventilação regional foi avaliada por tomografia por impedância elétrica. Mensuração de citocinas séricas e exames histopatológicos pulmonares também foram efetuados. Resultados: Todos os animais dos quatro grupos que receberam a endotoxina desenvolveram hipertensão pulmonar e lesão pulmonar aguda ao longo do experimento. O grupo Hemo+LPS apresentou alta mortalidade (56%), com alterações hemodinâmicas mais acentuadas do que as observadas nos grupos Hemo e LPS. Os grupos Conv e dPP apresentaram o mesmo grau de comprometimento hemodinâmico observado inicialmente no grupo Hemo+LPS, mas houve rápida recuperação em reposta ao tratamento e todos sobreviveram. Entre os grupos tratados não houve diferenças significantes em relação ao volume de cristalóides administrado (volume total, P=0,066) ou ao débito urinário, mas a PVC no grupo Conv foi significantemente superior à dos grupos dPP (P=0,031) e Sham (P=0,048) ao final do protocolo. Entre as variáveis utilizadas como metas, áreas sob as curvas de características operacionais para predição de fluido-responsividade foram maiores para PVC (0,77; IC95%, 0,68-0,86) e VPP (0,74; IC95%, 0,65-0,83), sendo ambas estas variáveis selecionadas por regressão logística múltipla como variáveis independentes para predição de não-responsividade ao desafio volêmico (PVC: P=0,001, razão de chances, 1,7; IC95%, 1,25-2,32 e VPP: P=0,01, razão de chances, 0,91; IC95%, 0,84-0,98). O melhor valor de corte para VPP para maximização de sua função preditiva foi 15%, com sensibilidade 0,75 (IC95%, 0,63-0,85) e especificidade 0,64 (IC95% 0,49-0,77%). Resultados falso-positivos para VPP foram observados em condições de pressão arterial pulmonar média ≥ 27 mmHg e gradiente transpulmonar ≥ 14 mmHg, acompanhados de índice de resistência vascular pulmonar médio > 3 unidades Wood. Resultados falso-negativos também foram constatados. Conclusões: O presente modelo experimental de choque hemorrágico agudo com endotoxemia produziu intenso comprometimento hemodinâmico, hipertensão pulmonar, lesão pulmonar aguda e, na ausência de tratamento, alta mortalidade. Nestas condições, a ressuscitação aguda com cristalóides guiada por VPP e PAM não produziu resultados inferiores à estratégia guiada por metas de ressuscitação convencionalmente estabelecidas, com base em PVC, PAM e SvO2. A principal diferença em desfecho entre as estratégias de ressuscitação foi indução de uma PVC significantemente maior no segundo grupo, ao final do protocolo. Apesar de seus desempenhos individuais terem sido considerados limitados em relação à predição de fluido-responsividade, PVC e VPP foram preditoras independentes de não-responsividade ao desafio volêmico, de modo que sua aplicação em conjunto deva ser investigada. VPP é proposta como uma variável adicional para auxiliar no monitoramento de pacientes, sendo o conhecimento de suas limitações indispensável. / Introduction: Fluid therapy is first-line treatment for patients in hemorrhagic or septic shock for the restoration of circulating volume and tissue perfusion, but several issues remain under debate, particularly regarding resuscitation goals represented by physiological variables to be achieved. Pulse pressure variation (PPV) has been proposed as a reliable index for the prediction of fluid responsiveness in mechanically ventilated patients, but further evaluation for its use in diverse conditions is required. Objective: To compare acute fluid resuscitation guided by PPV and mean arterial pressure (MAP) to another strategy consisting of conventionally-established goals, based on central venous pressure (CVP), MAP and mixed-venous oxygen saturation (SvO2), during experimental acute hemorrhagic shock with endotoxemia. An experimental model was developed to this end and each variable used as resuscitation goal was evaluated additionally for its ability to predict fluid-responsiveness. Methods: Fifty-one pigs were anesthetized, mechanically ventilated and, after preparation, randomized into six groups: control (Sham, n=8); intravenous infusion of endotoxin in decreasing doses (LPS, n=8); hemorrhagic shock of 50% the estimated blood volume in 20 minutes (Hemo, n=8); hemorrhagic shock with endotoxemia in accordance with protocols in groups LPS and Hemo (Hemo+LPS, n=9); hemorrhagic shock with endotoxemia followed by resuscitation with crystalloids, after 60 minutes, to achieve and maintain CVP 12-15 mmHg, MAP ≥ 65 mmHg and SvO2 ≥ 65% (Conv, n=9); hemorrhagic shock with endotoxemia followed by resuscitation with crystalloids, after 60 minutes, to achieve and maintain PPV ≤ 13% and MAP ≥ 65 mmHg (dPP, n=9). Treatments lasted for three hours. In addition to hemodynamic assessment including thermodilution and transesophageal echocardiography, arterial blood-gases with measurement of electrolytes and lactate, mixed-venous blood-gases and intestinal tonometry were performed. Regional ventilation was evaluated by electrical impedance tomography. Lung histopathology and measurement of serum cytokines were performed as well. Results: All animals from the four groups submitted to endotoxemia developed pulmonary hypertension and acute lung injury over the experimental period. Group Hemo+LPS presented with a high mortality rate (56%) and hemodynamic impairment which was more intense than that observed in groups Hemo or LPS. Groups Conv and dPP developed the same degree of hemodynamic compromise observed in group Hemo+LPS initially, but there was quick recovery in response to treatment and all pigs survived. Between treated groups there were no significant differences in amounts of crystalloids infused (total volume, P=0.066) or in urinary output, but CVP in group Conv was significantly higher than in groups dPP (P=0.031) and Sham (P=0.048) at the end of the study period. Among variables used as goals, areas under the receiver-operator characteristic curves regarding prediction of fluid-responsiveness were larger for CVP (0.77; 95%CI, 0.68-0.86) and PPV (0.74; 95%CI, 0.65-0.83), and both these variables were selected by multiple logistic regression as independent predictors of non-responsiveness to fluid challenge (CVP: P=0.001, odds ratio, 1.7; 95%CI, 1.25-2.32 and PPV: P=0.010, odds ratio, 0.91; 95%CI, 0.84-0.98). Best cutoff value to maximize the predictive function of PPV was 15%, with sensitivity 0.75 (95%CI, 0.63-0.85) and specificity 0.64 (95%CI 0.49-0.77). False positive results for PPV were observed at mean arterial pressure ≥ 27 mmHg and transpulmonary gradient ≥ 14 mmHg, with mean pulmonary vascular resistance index > 3 Wood units. False negative results were also detected. Conclusions: This model of acute hemorrhagic shock with endotoxemia produced severe hemodynamic compromise, pulmonary hypertension, acute lung injury and, in the absence of treatment, a high mortality rate. In this setting, acute resuscitation with crystalloids guided by PPV and MAP was not inferior to the strategy guided by conventionally-established goals, based on CVP, MAP and SvO2. The main difference in outcome between resuscitation strategies was the induction of a significantly higher CVP in the second group, at the end of protocol. Although their individual performances were considered limited for the prediction of fluid-responsiveness, CVP and PPV were independent predictors of non-responsiveness to fluid challenge, so that their combined use should be investigated further. PPV is proposed as an additional variable to aid in patient monitoring, but awareness of its limitations is indispensable.

<p>Akutno bubrežno o&scaron;tećenje je česta i ozbiljna komplikacija nakon hirur&scaron;ke rekonstrukcije abdominalne aorte. Ona produžuje, poskupljuje bolničko lečenje i povećava morbiditet i mortalitet bolesnika. &Scaron;to ranije prepoznavanje bolesnika koji su pod povi&scaron;enim rizikom uz pomoć prediktivnih faktora, kao i identifikovanje akutnog bubrežnog o&scaron;tećenja od velikog je značaja za pravovremeno započinjanje preventivnih i terapijskih mera i smanjenje mortaliteta ovih bolesnika. Cilj istraživanja: Utvrditi incidencu akutnog bubrežnog o&scaron;tećenja, najznačajnije preoperativne i intraoperativne prediktivne faktore za nastanak akutnog bubrežnog o&scaron;tećenja i utvrditi da li serumski cistatin C ranije i preciznije ukazuje na akutno bubrežno o&scaron;tećenje u odnosu na serumski kreatinin 72 sata nakon elektivnih operacija na infrarenalnom segmentu aorte. Metodologija: Na Klinici za anesteziju, intenzivnu terapiju i terapiju bola i Klinici za vaskularnu i transplantacionu hirurgiju Kliničkog centra Vojvodine sprovedeno je prospektivno opservaciono istraživanje u trajanju od 18 meseci, od oktobra 2017. do aprila 2019. godine. U istraživanje je uključeno 140 pacijenata koji su podvrgnuti elektivnom operativnom zahvatu na infrarenalnom segmentu aorte. Preoperativni i intraoperativni potencijalni prediktivni faktori identifikovani su iz medicinske dokumentacije: istorije bolesti, protokoli anestezije, dnevne terapijske liste, liste vitalnih parametara i liste laboratorijskih parametara. Nastanak ABO je potvrđivan pomoću AKIN klasifikacionog sistema. Tokom postoperativnog perioda lečenja od 72 sata obraćana je pažnja na vreme i stepen nastanka ABO. Za statističku obradu podataka kori&scaron;ćen je program SPSS, verzija 21 (IBM SPSS, Čikago, Ilinois). Rezultati su predstavljeni tabelarno i grafički, a statistički značajnim su se smatrale vrednosti nivoa značajnosti p&lt;0,05. Podaci su obrađivani standardnim statističkim testovima. Za dobijanje modela predikcije primenjena je multivarijantna logistička regresija. Rezultati: Incidenca akutnog bubrežnog o&scaron;tećenja nakon elektivnih operacija na infrarenalnom segmentu aorte na Klinici za anesteziju, intenzivnu terapiju i terapiju bola i Klinici za vaskularnu i transplantacionu hirurgiju Kliničkog centra Vojvodine iznosi 28,56%. Prema ROC analizi granična vrednost koncentracije cistatina C od 1,14 mg/l ima najvi&scaron;u senzitivnost (82,5%), i specifičnost (76%) u diferenciranju bolesnika koji će dobiti akutno bubrežno o&scaron;tećenje. Kompletan model predikcije ABO nakon elektivnih operacija na infrarenalnom segmentu aorte sadrži sledeće faktore: prisustvo hronične bubrežne slabosti, preoperativna serumska koncentracija cistatina C &gt;1,14 mg/l, primena koloida u volumenu &gt;500 ml u toku operacije, ukupni volumen nadoknade u intraoperativnom periodu &gt;59 ml/kg. Zaključak: Incidenca akutnog bubrežnog o&scaron;tećenja nakon elektivnih operacija na infrarenalnom segmentu aorte na Klinici za anesteziju, intenzivnu terapiju i terapiju bola i Klinici za vaskularnu i transplantacionu hirurgiju Kliničkog centra Vojvodine je ne&scaron;to vi&scaron;a u odnosu na literaturne podatke. Cistatin C je bolji prediktor i pokazatelj akutnog bubrežnog o&scaron;tećenja u odnosu na kreatinin. Bolesnici koji imaju hroničnu bubrežnu slabost, preoperativni nivo cistatina C&gt;1,14 mg/l, koji tokom operacije dobiju preko 500 ml koloidnih rastvora, i ukupni volumen nadoknade &gt;59 ml/kg imaju veću &scaron;ansu da dobiju akutno o&scaron;tećenje bubrega u postoperativnom periodu.</p> / <p>Acute kidney injury is frequent and serious complication after aortic surgery which increases length of hospital stay, costs, morbidity and mortality. Earlier recognition of patients at risk by predictive factors and identification of acute kidney injury could have important role on right timing of preventive and therapeutic measures and lower mortality of these patients. Aims: to investigate the incidence of acute kidney injury, the most important preoperative and intraoperative predictive factors for acute kidney injury, and check whether cystatin C indicates acute kidney injury earlier and more accurately than creatinine 72 hours after elective infrarenal aortic surgery. Methodology: This prospective observational study was performed at Clinic of Anesthesia, Intensive Care and Pain Therapy and Clinic of Vascular and Transplantation Surgery, Clinical Centre of Vojvodina, during the period of 18 months, from October 2017 till April 2019. It includes 140 adult patient who underwent elective infrarenal aortic surgery. Potential predictive factors were identified out of medical records such as: patient history, anesthesia lists, daily therapeutic lists, vital parameters and laboratory values lists. The occurrence of acute kidney injury was noted according to AKIN criteria. IBM SPSS version 21 (Chicago, Illinois) was used for statistical analysis. The results were presented in tables and graphs, statistical significance was set at p value of less than 0,05. Standard statistical tests were applied. Multivariate logistic regression model was used for potential predictive factors. Results: The incidence of acute kidney injury at Clinic of Anesthesia, Intensive Care and Pain Therapy and Clinic of Vascular and Transplantation Surgery, Clinical Centre of Vojvodina, was 28,56%. The cut off value of cystatin C serum concentration of 1,14 mg/l has the highest sensitivity (82,5%), and specificity (76%) in the differentiation of patients who will develop acute kidney injury. The final model for predicting acute kidney injury in patients who underwent elective infrarenal aortic surgery contains the following variables: presence of chronic kidney failure, preoperative serum concentration of cystatin C&gt;1,14 mg/l, application of colloid solutions in volume&gt;500 ml during the operation and total intravascular fluid replacement volume&gt;59 ml/kg in intraoperative period. Conclusion: The incidence of acute kidney injury at Clinic of Anesthesia, Intensive Care and Pain Therapy and Clinic of Vascular and Transplantation Surgery, Clinical Centre of Vojvodina, is somewhat higher comparing to world literature data. Patients who are more likely to develop acute kidney injury have: chronic kidney failure, preoperative serum concentration of cystatin C&gt;1,14 mg/l and get colloid solutions in volume&gt;500 ml and total intravascular fluid replacement volume&gt;59 ml/kg during intraoperative period.</p>

Background: Every year, more than 2 million people undergo cardiac surgery including 15 000 Canadians (1). Acute kidney injury remain a frequent complication in this setting which can affect up to 39% of patients (2). This complication is associated with a significant increase in the risk of short-term and long-term mortality after cardiac surgery (1). Multiple mechanisms can lead to acute kidney injury in the peri-operative period which complexify prevention and treatment. Among them, multiple clinical factors can result in an increase in venous pressure leading to a state of systemic congestion deleterious to kidney function in addition to other organs. The detection of congestion at the bedside of patients after cardiac surgery could be used to identify patients at risk of developing congestive complications such as congestive acute kidney injury as well as opening possibilities for prevention and treatment. Doppler ultrasound is a non-invasive technology enabling the assessment of blood flow velocity within the venous system. A reduction of systemic venous compliance lead to the appearance of alterations in portal vein flow and intra-renal venous flow. The objectives of the work presented in this thesis were the following: To determine the prevalence and predictive factor associated with the appearance of venous flow alterations during the intra-operative and post-operative period, to determine if their detection is associated with acute kidney injury in the post-operative period and to determine the clinical significance of their detection in the immediate post-operative period. Main results: This thesis is comprised of 3 cohort studies including a total of 1497 ultrasound asessments in 362 patients. Alterations in venous Doppler signals were observed in a subtantial proportion of patients during the per-operative period, from 10.8% to 24.3% depending on the time of assessment and the site assessed. We observed significant correlations between venous Doppler alterations and other clinical markers of congestion including central venous pressure, NT-pro-BNP and fluid balance. Furthermore, we observed that portal flow pulsatility and abnormal patterns of intrarenal venous flow were correlated. Using repeated assessments in a cohort of 145 patients, we observed that portal flow pulsatility and severe alterations in intrarenal venous flow were associated with the subsequent development of acute kidney injury in the post-operative period. A re-analysis of this data suggested that a grading system combining mutliple Doppler assesments at intensive care admission after cardiac surgery including heaptic veins, the portal vein and intrarenal veins may be able to identify patients at risk of developping acute kidney injury with high specificity. Conclusions: In the context of cardiac surgery, Doppler ultrasound can be used to identify alterations in peripheral venous Doppler signals suggestive of a congestion phenomenon and may be able to anticipate complications related to venous congestion such as acute kidney injury. / Contexte : Chaque année, plus de 2 millions de personnes subissent une chirurgie cardiaque, dont 15 000 Canadiens (1). L’insuffisance rénale aiguë demeure une complication fréquente chez les patients subissant une chirurgie cardiaque atteignant une incidence jusqu’à 39 % dans la période postopératoire (2). Cette complication est associée à une augmentation du risque de mortalité à court et long termes. Plusieurs mécanismes peuvent engendrer l’insuffisance rénale aiguë dans la période peropératoire, ce qui complexifie la prévention et le traitement. Parmi ceux-ci, divers facteurs peuvent engendrer une augmentation des pressions veineuses menant à un état de congestion systémique qui affecte la fonction des reins ainsi que celle des autres organes vitaux. La détection de la congestion au chevet des patients durant la période intraopératoire et postopératoire pourrait permettre d’identifier les individus à risque de développer des complications de nature congestive telles que l’insuffisance rénale aiguë ainsi que de mettre en place des stratégies de prévention et de traitement. L’échographie Doppler est une technologie non invasive qui permet d’évaluer la vélocité du sang dans le réseau veineux. La diminution de la compliance veineuse entraine l’apparition d’altérations du flot veineux de la veine porte et des veines intrarénales. Les objectifs des travaux présentés dans cette thèse étaient les suivants : déterminer la prévalence ainsi que les facteurs prédicteurs de l’apparition de ces altérations durant la période peropératoire; déterminer si la détection de ces altérations est en mesure de prédire l’apparition d’insuffisance rénale aiguë dans la période postopératoire; et déterminer quelle est la signification clinique de l’apparition de ces signes dans la période postopératoire immédiate. Résultats principaux : Les travaux contenus dans cette thèse comportent trois études de cohorte comprenant 1497 examens échographiques chez 362 patients. La présence d’altération du flot veineux a été observée chez une proportion substantielle des patients durant la période post-opératoire, allant de 10.8% à 24.3% selon le site intérrogé et le moment où l’examen est effectué. Nous avons observé des associations entre les altérations du flot veineux et les autres marqueurs de congestion incluant la pression veineuse centrale, la mesure du NT-pro-BNP et la balance liquidienne. De plus, nous avons observé que la pulsatilité du flot portal est corrélée aux altérations du signal Doppler dans les veines intrarénales. Grâce à des examens répétées effectuées dans une cohorte de 145 patients, nous avons observé que la pulsatilité du flot portal et la présence d’un profil compatible avec une anomalie sévère du flot intrarénal veineux étaient associées indépendamment avec la survenue subséquente d’insuffisance rénale aiguë durant la période postopératoire. Une réanalyse de ces données nous a permis de constater qu’un système de gradation combinant la présence des altérations du flot veineux à plusieurs sites, incluant les veines hépatiques, la veine porte et les veines intrarénales, au moment de l’admission aux soins intensifs permet d’indentifier les patients qui développeront une insuffisance rénale aiguë avec une spécificité élevée. Conclusions : Dans le contexte de la chirurgie cardiaque, l’échographie Doppler peut être utilisée au chevet afin d’indentifier des altérations du flot veineux périphérique suggestives d’un phénomène de congestion et d’anticiper les complications de nature congestive tel que l’insuffisance rénale aiguë.