Continuous Right Ventricular Pressure Monitoring in Cardiac Surgery.

OBJECTIVE: Right ventricular (RV) dysfunction in cardiac surgery can lead to RV failure, which is associated with increased morbidity and mortality. Abnormal RV function can be identified using RV pressure monitoring. The primary objective of the study is to determine the proportion of patients with abnormal RV early to end-diastole diastolic pressure gradient (RVDPG) and abnormal RV end-diastolic pressure (RVEDP) before initiation and after cardiopulmonary bypass (CPB) separation. The secondary objective is to evaluate if RVDPG before CPB initiation is associated with difficult and complex separation from CPB, RV dysfunction, and failure at the end of cardiac surgery. DESIGN: Prospective study. SETTING: Tertiary care cardiac institute. PARTICIPANTS: Cardiac surgical patients. INTERVENTION: Cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Automated electronic quantification of RVDPG and RVEDP were obtained. Hemodynamic measurements were correlated with cardiac and extracardiac parameters from transesophageal echocardiography and postoperative complications. Abnormal RVDPG was present in 80% of the patients (n = 105) at baseline, with a mean RVEDP of 14.2 ± 3.9 mmHg. Patients experienced an RVDPG > 4 mmHg for a median duration of 50.2% of the intraoperative period before CPB initiation and 60.6% after CPB separation. A total of 46 (43.8%) patients had difficult/complex separation from CPB, 18 (38.3%) patients had RV dysfunction, and 8 (17%) had RV failure. Abnormal RVDPG before CPB was not associated with postoperative outcome. CONCLUSION: Elevated RVDPG and RVEDP are common in cardiac surgery. RVDPG and RVEDP before CPB initiation are not associated with RV dysfunction and failure but can be used to diagnose them.

Pulmonary Vasodilator Response of Combined Inhaled Epoprostenol and Inhaled Milrinone in Cardiac Surgical Patients.

BACKGROUND: Pulmonary hypertension (PH) and right ventricular (RV) dysfunction are major complications in cardiac surgery. Intraoperative management of patients at high risk of RV failure should aim to reduce RV afterload and optimize RV filling pressures, while avoiding systemic hypotension, to facilitate weaning from cardiopulmonary bypass (CPB). Inhaled epoprostenol and inhaled milrinone (iE&iM) administered in combination before CPB may represent an effective strategy to facilitate separation from CPB and reduce requirements for intravenous inotropes during cardiac surgery. Our primary objective was to report the rate of positive pulmonary vasodilator response to iE&iM and, second, how it relates to perioperative outcomes in cardiac surgery. METHODS: This is a retrospective cohort study of consecutive patients with PH or RV dysfunction undergoing on-pump cardiac surgery at the Montreal Heart Institute from July 2013 to December 2018 (n = 128). iE&iM treatment was administered using an ultrasonic mesh nebulizer before the initiation of CPB. Demographic and baseline clinical data, as well as hemodynamic, intraoperative, and echocardiographic data, were collected using electronic records. An increase of 20% in the mean arterial pressure (MAP) to mean pulmonary artery pressure (MPAP) ratio was used to indicate a positive response to iE&iM. RESULTS: In this cohort, 77.3% of patients were responders to iE&iM treatment. Baseline systolic pulmonary artery pressure (SPAP) (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.24-2.16 per 5 mm Hg; P = .0006) was found to be a predictor of pulmonary vasodilator response, while a European System for Cardiac Operative Risk Evaluation (EuroSCORE II) score >6.5% was a predictor of nonresponse to treatment (≤6.5% vs >6.5% [reference]: OR, 5.19; 95% CI, 1.84-14.66; P = .002). Severity of PH was associated with a positive response to treatment, where a higher proportion of responders had MPAP values >30 mm Hg (42.4% responders vs 24.1% nonresponders; P = .0237) and SPAP values >55 mm Hg (17.2% vs 3.4%; P = .0037). Easier separation from CPB was also associated with response to iE&iM treatment (69.7% vs 58.6%; P = .0181). A higher proportion of nonresponders had a very difficult separation from CPB and required intravenous inotropic drug support compared to responders, for whom easy separation from CPB was more frequent. Use of intravenous inotropes after CPB was lower in responders to treatment (8.1% vs 27.6%; P = .0052). CONCLUSIONS: A positive pulmonary vasodilator response to treatment with a combination of iE&iM before initiation of CPB was observed in 77% of patients. Higher baseline SPAP was an independent predictor of pulmonary vasodilator response, while EuroSCORE II >6.5% was a predictor of nonresponse to treatment.

Assessment of fluid responsiveness in children using respiratory variations in descending aortic flow.

BACKGROUND: The primary aim of the current study was to investigate the ability of respiratory variations in descending aortic flow, measured with two-dimensional echo at the suprasternal notch (ΔVpeak dAo), to predict fluid responsiveness in anesthetized mechanically ventilated children. In addition, variations in peak descending aortic flow measured with apical transthoracic echo (ΔVpeak LVOT) were examined for the same properties. METHODS: Twenty-seven patients under general anesthesia were investigated in this prospective observational study. Cardiac output, ΔVpeak dAo, and ΔVpeak LVOT were measured at stable conditions after anesthesia induction. The measurements were repeated after a 10 mL kg-1 fluid bolus. Patients were classified as responders if stroke volume index increased by >15% after fluid bolus. The ability of each parameter to predict fluid responsiveness was assessed using receiver operating characteristic curves. RESULTS: Twenty-seven patients were analyzed, mean age and weight 43 months and 16 kg, respectively. Twelve responders and 15 non-responders were identified. ΔVpeak dAo was significantly higher in the responder group (14%, 95% confidence interval [CI]: 12%-17%) compared to the non-responder group (11%, 95% CI: 9%-13%) (p = .04) at baseline. Area under the ROC curve for ΔVpeak dAo and ΔVpeak LVOT was 0.73 (95% CI: 0.52-0.89, p = .02) and 0.56 (0.34-0.78, p = .3), respectively. A baseline level of ΔVpeak dAo of >14% predicted fluid responsiveness with a sensitivity of 58% (95% CI: 28%-85%) and specificity of 73% (95% CI: 45%-92%). CONCLUSION: In mechanically ventilated children, ΔVpeak dAo identified fluid responders with moderate diagnostic power in the current study. ΔVpeak LVOT failed to predict fluid responders in the current study.

Proceedings of the 2022 UAB CRRT Academy: Non-Invasive Hemodynamic Monitoring to Guide Fluid Removal with CRRT and Proliferation of Extracorporeal Blood Purification Devices.

In 2022, we celebrated the 15th anniversary of the University of Alabama at Birmingham (UAB) Continuous Renal Replacement Therapy (CRRT) Academy, a 2-day conference attended yearly by an international audience of over 100 nephrology, critical care, and multidisciplinary trainees and practitioners. This year, we introduce the proceedings of the UAB CRRT Academy, a yearly review of select emerging topics in the field of critical care nephrology that feature prominently in the conference. First, we review the rapidly evolving field of non-invasive hemodynamic monitoring and its potential to guide fluid removal by renal replacement therapy (RRT). We begin by summarizing the accumulating data associating fluid overload with harm in critical illness and the potential for harm from end-organ hypoperfusion caused by excessive fluid removal with RRT, underscoring the importance of accurate, dynamic assessment of volume status. We describe four applications of point-of-care ultrasound used to identify patients in need of urgent fluid removal or likely to tolerate fluid removal: lung ultrasound, inferior vena cava ultrasound, venous excess ultrasonography, and Doppler of the left ventricular outflow track to estimate stroke volume. We briefly introduce other minimally invasive hemodynamic monitoring technologies before concluding that additional prospective data are urgently needed to adapt these technologies to the specific task of fluid removal by RRT and to learn how best to integrate them into practical fluid-management strategies. Second, we focus on the growth of novel extracorporeal blood purification devices, starting with brief reviews of the inflammatory underpinnings of multiorgan dysfunction and the specific applications of pathogen, endotoxin, and/or cytokine removal and immunomodulation. Finally, we review a series of specific adsorptive technologies, several of which have seen substantial clinical use during the COVID-19 pandemic, describing their mechanisms of target removal, the limited existing data supporting their efficacy, ongoing and future studies, and the need for additional prospective trials.

Higher portal venous pulsatility is associated with worse clinical outcomes following congenital heart surgery: a single-centre prospective cohort study.

PURPOSE: Increased portal venous flow pulsatility is associated with major complications after adult cardiac surgery. Nevertheless, no data are available for pediatric patients with congenital heart disease. We hypothesized that Doppler parameters including portal flow pulsatility could be associated with postoperative outcomes in children undergoing various cardiac surgeries. METHODS: We conducted a prospective observational cohort study in children undergoing congenital cardiac surgery. We obtained postoperative portal, splenic, and hepatic venous Doppler data and perioperative clinical data including major postoperative complications. Portal and splenic venous flow pulsatility were calculated. We evaluated the association between venous Doppler parameters and adverse outcomes. The primary objective was to determine whether postoperative portal flow pulsatility could indicate major complications following congenital heart surgery. RESULTS: In this study, we enrolled 389 children, 74 of whom experienced major postoperative complications. The mean (standard deviation) portal pulsatility (44 [30]% vs 25 [14]%; 95% confidence interval [CI] for mean difference, 12 to 26; P < 0.001] and splenic pulsatility indices (41 [30]% vs 26 [16]%; 95% CI, 7 to 23; P < 0.001) were significantly higher in children with postoperative complications than in those without complications. The portal pulsatility index was able to help identify postoperative complications in biventricular patients and univentricular patients receiving bidirectional cavopulmonary shunt whereas it did not in other univentricular patients. An increased postoperative portal pulsatility index was significantly associated with major complications after pediatric cardiac surgery (odds ratio, 1.40; 95% CI, 1.29 to 1.91; P < 0.001). CONCLUSIONS: Higher portal venous pulsatility is associated with major postoperative complications in children undergoing cardiac surgery. Nevertheless, more data are needed to conclude the efficacy of portal venous pulsatility in patients with univentricular physiology. STUDY REGISTRATION: ClinicalTrials.gov (NCT03990779); registered 19 June 2019.

RéSUMé: OBJECTIF: L'augmentation de la pulsatilité du flux de la veine porte est associée à des complications majeures après une chirurgie cardiaque chez l'adulte. Néanmoins, aucune donnée n'est disponible pour la patientèle pédiatrique atteinte de cardiopathie congénitale. Nous avons émis l'hypothèse que les paramètres Doppler, y compris la pulsatilité du flux de la veine porte, pourraient être associés aux devenirs postopératoires des enfants bénéficiant de diverses chirurgies cardiaques. MéTHODE: Nous avons réalisé une étude de cohorte observationnelle prospective portant sur des enfants bénéficiant d'une chirurgie cardiaque congénitale. Nous avons obtenu des données Doppler des veines porte, spléniques et hépatiques postopératoires ainsi que des données cliniques périopératoires, y compris les complications postopératoires majeures. La pulsatilité du flux des veines porte et spléniques a été calculée. Nous avons évalué l'association entre les paramètres Doppler veineux et les issues indésirables. L'objectif principal était de déterminer si la pulsatilité du flux postopératoire de la veine porte pouvait constituer un indicateur des complications majeures après une chirurgie cardiaque congénitale. RéSULTATS: Dans cette étude, nous avons recruté 389 enfants, dont 74 ont présenté des complications postopératoires majeures. La pulsatilité moyenne de la veine porte (écart type) (44 [30] % vs 25 [14] %; intervalle de confiance [IC] à 95 % pour la différence moyenne, 12 à 26; P < 0,001] et les indices de pulsatilité splénique (41 [30] % vs 26 [16] %; IC 95 %, 7 à 23; P < 0,001) étaient significativement plus élevés chez les enfants présentant des complications postopératoires que chez les enfants sans complications. L'indice de pulsatilité de la veine porte a permis d'identifier les complications postopératoires chez les patient·es biventriculaires et les patient·es univentriculaires recevant une anastomose cavo-pulmonaire bidirectionnelle (procédure de Glenn), alors que ce n'était pas le cas chez les autres patient·es univentriculaires. Une augmentation postopératoire de l'indice de pulsatilité de la veine porte était significativement associée à des complications majeures après une chirurgie cardiaque pédiatrique (rapport de cotes, 1,40; IC 95 %, 1,29 à 1,91; P < 0,001). CONCLUSION: Une pulsatilité plus élevée de la veine porte est associée à des complications postopératoires majeures chez les enfants bénéficiant d'une chirurgie cardiaque. Néanmoins, davantage de données sont nécessaires pour conclure à l'efficacité de la pulsatilité de la veine porte chez les patient·es présentant une physiologie univentriculaire. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT03990779); enregistrée le 19 juin 2019.

Evaluation of Portal, Splenic, and Hepatic Vein Flows in Children Undergoing Congenital Heart Surgery.

OBJECTIVE: Little is known about changes in portal, splenic, and hepatic vein flow patterns in children undergoing congenital heart surgery. This study aimed to determine the characteristics of portal, splenic, and hepatic vein flow patterns using ultrasonography in children undergoing cardiac surgery. DESIGN: Single-center, prospective observational study. SETTING: Tertiary children's hospital, operating room. PARTICIPANTS: Children undergoing cardiac surgery. MEASUREMENT AND MAIN RESULTS: The authors obtained ultrasound data from the heart, inferior vena cava, portal, splenic, and hepatic veins before and after surgeries. In the biventricular group, which included children with atrial and ventricular septal defects and pulmonary stenosis (n = 246), the portal pulsatility index decreased from 38.7% to 25.6% (p < 0.001) after surgery. The preoperative portal pulsatility index was significantly higher in patients with pulmonary hypertension (43.3% v 27.4%; p < 0.001). In the single-ventricle group (n = 77), maximum portal vein flow velocities of Fontan patients were significantly lower (13.5 cm/s) compared with that of patients with modified Blalock-Taussig shunt (19.7 cm/s; p = 0.035) or bidirectional cavopulmonary shunt (23.1 cm/s; p < 0.001). The cardiac index was inversely correlated with the portal pulsatility index in the bidirectional cavopulmonary shunt and Fontan circulation. (ß = -5.693, r2 = 0.473; p = 0.001) The portal pulsatility index was correlated with splenic venous pulsatility and hepatic venous atrial reverse flow velocity in biventricular and single-ventricle groups. CONCLUSIONS: The characteristics of venous Doppler patterns in the portal, splenic, and hepatic veins differed according to congenital heart disease. Further studies are required to determine the association between splanchnic venous Doppler findings and clinical outcomes in this population.

Fluid balance and renal replacement therapy initiation strategy: a secondary analysis of the STARRT-AKI trial.

BACKGROUND: Among critically ill patients with acute kidney injury (AKI), earlier initiation of renal replacement therapy (RRT) may mitigate fluid accumulation and confer better outcomes among individuals with greater fluid overload at randomization. METHODS: We conducted a pre-planned post hoc analysis of the STandard versus Accelerated initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial. We evaluated the effect of accelerated RRT initiation on cumulative fluid balance over the course of 14 days following randomization using mixed models after censoring for death and ICU discharge. We assessed the modifying effect of baseline fluid balance on the impact of RRT initiation strategy on key clinical outcomes. Patients were categorized in quartiles of baseline fluid balance, and the effect of accelerated versus standard RRT initiation on clinical outcomes was assessed in each quartile using risk ratios (95% CI) for categorical variables and mean differences (95% CI) for continuous variables. RESULTS: Among 2927 patients in the modified intention-to-treat analysis, 2738 had available data on baseline fluid balance and 2716 (92.8%) had at least one day of fluid balance data following randomization. Over the subsequent 14 days, participants allocated to the accelerated strategy had a lower cumulative fluid balance compared to those in the standard strategy (4509 (- 728 to 11,698) versus 5646 (0 to 13,151) mL, p = 0.03). Accelerated RRT initiation did not confer greater 90-day survival in any of the baseline fluid balance quartiles (quartile 1: RR 1.11 (95% CI 0.92 to 1.34), quartile 2: RR 1.03 (0.87 to 1.21); quartile 3: RR 1.08 (95% CI 0.91 to 1.27) and quartile 4: RR 0.87 (95% CI 0.73 to 1.03), p value for trend 0.08). CONCLUSIONS: Earlier RRT initiation in critically ill patients with AKI conferred a modest attenuation of cumulative fluid balance. Nonetheless, among patients with greater fluid accumulation at randomization, accelerated RRT initiation did not have an impact on all-cause mortality. TRIAL REGISTRATION: ClinicalTrials.gov number, https://clinicaltrials.gov/ct2/show/NCT02568722 , registered October 6, 2015.

Perioperative Doppler ultrasound assessment of portal vein flow pulsatility in high-risk cardiac surgery patients: a multicentre prospective cohort study.

BACKGROUND: Portal vein Doppler ultrasound pulsatility measured by transoesophageal echocardiography is a marker of the haemodynamic impact of venous congestion in cardiac surgery. We investigated whether the presence of abnormal portal vein flow pulsatility is associated with a longer duration of invasive life support and postoperative complications in high-risk patients. METHODS: In this multicentre cohort study, pulsed-wave Doppler ultrasound assessments of portal vein flow were performed during anaesthesia before initiation of cardiopulmonary bypass (before CPB) and after separation of cardiopulmonary bypass (after CPB). Abnormal pulsatility was defined as portal pulsatility fraction (PPF) ≥50% (PPF50). The primary outcome was the cumulative time in perioperative organ dysfunction (TPOD) requiring invasive life support during 28 days. Secondary outcomes included major postoperative complications. RESULTS: 373 patients, 71 (22.0%) had PPF50 before CPB and 77 (24.9%) after CPB. PPF50 was associated with longer duration of TPOD (median [inter-quartile range]; before CPB: 27 h [11-72] vs 19 h [8.5-42], P=0.02; after CPB: 27 h [11-61] vs 20 h [8-42], P=0.006). After adjusting for confounders, PPF50 before CPB showed significant association with TPOD. PPF50 after CPB was associated with a higher rate of major postoperative complications (36.4% vs 20.3%, P=0.006). CONCLUSIONS: Abnormal portal vein flow pulsatility before cardiopulmonary bypass was associated with longer duration of life support therapy after cardiac surgery in high-risk patients. Abnormal portal vein flow pulsatility after cardiopulmonary bypass separation was associated with a higher risk of major postoperative complications although this association was not independent of other factors. CLINICAL TRIAL REGISTRATION: NCT03656263.

Early Detection and Correction of Cerebral Desaturation With Noninvasive Oxy-Hemoglobin, Deoxy-Hemoglobin, and Total Hemoglobin in Cardiac Surgery: A Case Series.

Regional cerebral oxygen saturation (rS o2 ) obtained from near-infrared spectroscopy (NIRS) provides valuable information during cardiac surgery. The rS o2 is calculated from the proportion of oxygenated to total hemoglobin in the cerebral vasculature. Root O3 cerebral oximetry (Masimo) allows for individual identification of changes in total (ΔcHbi), oxygenated (Δ o2 Hbi), and deoxygenated (ΔHHbi) hemoglobin spectral absorptions. Variations in these parameters from baseline help identify the underlying mechanisms of cerebral desaturation. This case series represents the first preliminary description of Δ o2 Hbi, ΔHHbi, and ΔcHbi variations in 10 cardiac surgical settings. Hemoglobin spectral absorption changes can be classified according to 3 distinct variations of cerebral desaturation. Reduced cerebral oxygen content or increased cerebral metabolism without major blood flow changes is reflected by decreased Δ o2 Hbi, unchanged ΔcHbi, and increased ΔHHbi Reduced cerebral arterial blood flow is suggested by decreased Δ o2 Hbi and ΔcHbi, with variable ΔHHbi. Finally, acute cerebral congestion may be suspected with increased ΔHHbi and ΔcHbi with unchanged Δ o2 Hbi. Cerebral desaturation can also result from mixed mechanisms reflected by variable combination of those 3 patterns. Normal cerebral saturation can occur, where reduced cerebral oxygen content such as anemia is balanced by a reduction in cerebral oxygen consumption such as during hypothermia. A summative algorithm using rS o2 , Δ o2 Hbi, ΔHHbi, and ΔcHbi is proposed. Further explorations involving more patients should be performed to establish the potential role and limitations of monitoring hemoglobin spectral absorption signals.

Intermittent Convective Therapies in Patients with Acute Kidney Injury: A Systematic Review with Meta-Analysis.

INTRODUCTION: In critically ill patients requiring intermittent renal replacement therapy (RRT), the benefits of convective versus diffusive clearance remain uncertain. We conducted a systematic review and meta-analysis to determine the safety, clinical efficacy, and clearance efficiency of hemofiltration (HF) and hemodiafiltration (HDF) compared to hemodialysis (HD) in patients with acute kidney injury (AKI) receiving intermittent RRT. METHOD: We searched Medline, Embase, Cochrane Library, and PROSPERO. We included clinical trials and observational studies that reported the use of intermittent HF or HDF in adult patients with AKI. The following outcomes were included: mortality, renal recovery, clearance efficacy, intradialytic hemodynamic stability, circuit loss, and inflammation modulation. RESULTS: A total of 3,169 studies were retrieved and screened. Four randomized controlled trials and 4 observational studies were included (n: 615 patients). Compared with conventional HD, intermittent convective therapies had no effect on in-hospital mortality (relative risk, 1.23; 95% confidence interval (CI), 0.76-1.99), renal recovery at 30 days (RR, 0.98; 95% CI, 0.82-1.16), time-to-renal recovery (mean difference [MD], 0.77; 95% CI, -6.56 to 8.10), and number of dialysis sessions until renal recovery (MD, -1.34; 95% CI, -3.39 to 0.72). The overall quality of included studies was low, and dialysis parameters were suboptimal for all included studies. CONCLUSION: This meta-analysis suggests that there is no significant difference in short-term mortality and renal recovery in patients with severe AKI when treated with intermittent HF or HDF compared to conventional HD. This systematic review emphasizes the need for further trials evaluating optimal convective parameters in AKI patients treated with intermittent dialysis.

Intra-abdominal pressure during and after cardiac surgery: a single-centre prospective cohort study.

PURPOSE: While intra-abdominal hypertension (IAH) has been associated with adverse outcomes in multiple settings, the epidemiology and clinical implications of IAH in the context of cardiac surgery are less known. In this study, we aimed to describe the prevalence of IAH in patients undergoing cardiac surgery and determine its association with patient characteristics and postoperative outcomes. METHODS: We conducted a single-centre prospective cohort study in which intra-abdominal pressure was measured in the operating room after general anesthesia (T1), after the surgical procedure (T2), and two hours after intensive care unit (ICU) admission (T3) in a subset of patients. Intra-abdominal hypertension was defined as intra-abdominal pressure (IAP) ≥ 12 mm Hg. Postoperative outcomes included death, acute kidney injury (AKI), and length of stay in the ICU and hospital. RESULTS: A total of 513 IAP measurements were obtained from 191 participants in the operating room and 131 participants in the ICU. Intra-abdominal hypertension was present in 105/191 (55%) at T1, 115/191 (60%) at T2, and 31/131 (24%) at T3. Intra-abdominal pressure was independently associated with body mass index, central venous pressure, and mean pulmonary artery pressure but was not associated with cumulative fluid balance. Intraoperative IAH was not associated with adverse outcomes including AKI. CONCLUSIONS: Intra-abdominal hypertension is very common during cardiac surgery but its clinical implications are uncertain.

RéSUMé: OBJECTIF: Bien que l'hypertension intra-abdominale (HIA) ait été associée à des issues indésirables dans de multiples contextes, l'épidémiologie et les implications cliniques de l'HIA dans le contexte de la chirurgie cardiaque sont moins connues. Dans cette étude, nous avons cherché à décrire la prévalence de l'HIA chez les patients bénéficiant d'une chirurgie cardiaque et à déterminer son association avec les caractéristiques des patients et les issues postopératoires. MéTHODE: Nous avons mené une étude de cohorte prospective monocentrique dans laquelle la pression intra-abdominale a été mesurée en salle d'opération après une anesthésie générale (T1), après l'intervention chirurgicale (T2) et deux heures après l'admission à l'unité de soins intensifs (USI) (T3) dans un sous-ensemble de patients. L'hypertension intra-abdominale a été définie comme une pression intra-abdominale (PIA) ≥ 12 mmHg. Les issues postopératoires comprenaient le décès, l'insuffisance rénale aiguë (IRA), et la durée du séjour à l'USI et à l'hôpital. RéSULTATS: Au total, 513 mesures de la PIA ont été obtenues auprès de 191 participants en salle d'opération et de 131 participants à l'USI. L'hypertension intra-abdominale était présente chez 105/191 patients (55 %) à T1, 115/191 (60 %) à T2 et 31/131 (24 %) à T3. La pression intra-abdominale était indépendamment associée à l'indice de masse corporelle, à la pression veineuse centrale et à la pression artérielle pulmonaire moyenne, mais n'était pas associée à un bilan hydrique cumulatif. L'HIA peropératoire n'était pas associée à des issues indésirables, y compris à l'IRA. CONCLUSION: L'hypertension intra-abdominale est très fréquente lors d'une chirurgie cardiaque, mais ses implications cliniques sont incertaines.

Constrictive pericarditis: portal, splenic, and femoral venous Doppler pulsatility: a case series.

PURPOSE: Pulsatile flow of the portal vein has been implicated as an indicator of right ventricular dysfunction in cardiac patients. In patients with significantly elevated right atrial pressure, pulsatile venous flow may be transmitted to the portal, splenic, renal, and femoral veins. We describe the evolution of these echocardiographic findings in four patients with constrictive pericarditis (CP) undergoing pericardiectomy with simultaneous hemodynamic waveform and cerebral oximetry monitoring in the operating room and in the intensive care unit. CLINICAL FEATURES: Patient 1 presented classic signs of CP, including equalization of left and right diastolic pressures, a "square root" sign on the diastolic portion of the right ventricular pressure curve, and elevated right atrial pressure. Preoperative transesophageal echocardiography showed a hyperdynamic left ventricle and dilated right ventricle with abnormal pulsatile waveforms in the portal and splenic veins. Surgical decompression of the pericardium gradually normalized the Doppler waveforms. Increased venous return following pericardiectomy during surgery in patients 2 and 3 and during the postoperative period in patient 4 resulted in right ventricular (RV) failure due to significantly increased preload. Venous pulsatility was also observed in the portal, splenic, and femoral veins. CONCLUSION: In patients with CP, changes in hemodynamic and echocardiographic signs of RV dysfunction are rapidly reflected by changes in peripheral venous velocities. Identifying signs of splanchnic and peripheral vascular venous congestion could help identify patients at higher risk of developing postoperative complications following pericardiectomy.

RéSUMé: OBJECTIF : Le flux pulsatile de la veine porte a été impliqué comme indicateur de dysfonctionnement ventriculaire droit chez les patients de chirurgie cardiaque. Le flux veineux pulsatile pourrait être transmis aux veines porte, splénique, rénale et fémorale chez les patients présentant une pression auriculaire droite significativement élevée. Nous décrivons l'évolution de ces observations échocardiographiques chez quatre patients atteints de péricardite constrictive (PC) bénéficiant d'une péricardectomie avec monitorage simultané de la forme d'onde hémodynamique et de l'oxymétrie cérébrale en salle d'opération et à l'unité de soins intensifs. CARACTéRISTIQUES CLINIQUES: Le patient 1 présentait des signes classiques de PC, y compris l'égalisation des pressions diastoliques gauche et droite, un signe de « racine carrée ¼ sur la partie diastolique de la courbe de pression ventriculaire droite, et une pression auriculaire droite élevée. L'échocardiographie transœsophagienne préopératoire a montré un ventricule gauche hyperdynamique et un ventricule droit dilaté, avec des formes d'onde pulsatiles anormales dans les veines porte et splénique. La décompression chirurgicale du péricarde a progressivement normalisé les formes d'onde Doppler. L'augmentation du retour veineux suivant une péricardectomie, survenue pendant la chirurgie chez les patients 2 et 3 et en période postopératoire chez le patient 4, a entraîné une défaillance ventriculaire droite (VD) due à l'augmentation significative de la précharge. La pulsatilité veineuse a également été observée dans les veines porte, splénique et fémorale. CONCLUSION: Chez les patients atteints de péricardite constrictive, les changements dans les signes hémodynamiques et échocardiographiques de dysfonctionnement du VD sont rapidement reflétés par des changements dans la vélocité veineuse périphérique. L'identification des signes de congestion veineuse splanchnique et vasculaire périphérique pourrait aider à identifier les patients présentant un risque plus élevé de manifester des complications postopératoires après une péricardectomie.

Impact of Processed Electroencephalography in Cardiac Surgery: A Retrospective Analysis.

OBJECTIVE: The use of brain function monitoring with processed electroencephalography (pEEG) during cardiac surgery is gaining interest for the optimization of hypnotic agent delivery during the maintenance of anesthesia. The authors sought to determine whether the routine use of pEEG-guided anesthesia is associated with a reduction of hemodynamic instability during cardiopulmonary bypass (CPB) separation and subsequently reduces vasoactive and inotropic requirements in the intensive care unit. DESIGN: This is a retrospective cohort study based on an existing database. SETTING: A single cardiac surgical center. PARTICIPANTS: Three hundred patients undergoing cardiac surgery, under CPB, between December 2013 and March 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred and fifty patients had pEEG-guided anesthesia, and 150 patients did not have a pEEG-guided anesthesia. Multiple logistic regression demonstrated that pEEG-guided anesthesia was not associated with a successful CPB separation (p = 0.12). However, the use of pEEG-guided anesthesia reduced by 57% the odds of being in a higher category for vasoactive inotropic score compared to patients without pEEG (odds ratio = 0.43; 95% confidence interval: 0.26-0.73; p = 0.002). Duration of mechanical ventilation, fluid balance, and blood losses were also reduced in the pEEG anesthesia-guided group (p < 0.003), but there were no differences in organ dysfunction duration and mortality. CONCLUSION: During cardiac surgery, pEEG-guided anesthesia allowed a reduction in the use of inotropic or vasoactive agents at arrival in the intensive care unit. However, it did not facilitate weaning from CPB compared to a group where pEEG was unavailable. A pEEG-guided anesthetic management could promote early vasopressor weaning after cardiac surgery.

Short-term antibody response after 1 dose of BNT162b2 vaccine in patients receiving hemodialysis.

BACKGROUND: Patients receiving in-centre hemodialysis are at high risk of exposure to SARS-CoV-2 and death if infected. One dose of the BNT162b2 SARS-CoV-2 vaccine is efficacious in the general population, but responses in patients receiving hemodialysis are uncertain. METHODS: We obtained serial plasma from patients receiving hemodialysis and health care worker controls before and after vaccination with 1 dose of the BNT162b2 mRNA vaccine, as well as convalescent plasma from patients receiving hemodialysis who survived COVID-19. We measured anti-receptor binding domain (RBD) immunoglobulin G (IgG) levels and stratified groups by evidence of previous SARS-CoV-2 infection. RESULTS: Our study included 154 patients receiving hemodialysis (135 without and 19 with previous SARS-CoV-2 infection), 40 controls (20 without and 20 with previous SARS-CoV-2 infection) and convalescent plasma from 16 patients. Among those without previous SARS-CoV-2 infection, anti-RBD IgG was undetectable at 4 weeks in 75 of 131 (57%, 95% confidence interval [CI] 47% to 65%) patients receiving hemodialysis, compared with 1 of 20 (5%, 95% CI 1% to 23%) controls (p < 0.001). No patient with nondetectable levels at 4 weeks developed anti-RBD IgG by 8 weeks. Results were similar in non-immunosuppressed and younger individuals. Three patients receiving hemodialysis developed severe COVID-19 after vaccination. Among those with previous SARS-CoV-2 infection, median anti-RBD IgG levels at 8 weeks in patients receiving hemodialysis were similar to controls at 3 weeks (p = 0.3) and to convalescent plasma (p = 0.8). INTERPRETATION: A single dose of BNT162b2 vaccine failed to elicit a humoral immune response in most patients receiving hemodialysis without previous SARS-CoV-2 infection, even after prolonged observation. In those with previous SARS-CoV-2 infection, the antibody response was delayed. We advise that patients receiving hemodialysis be prioritized for a second BNT162b2 dose at the recommended 3-week interval.

Frailty status among older critically ill patients with severe acute kidney injury.

BACKGROUND: Frailty status among critically ill patients with acute kidney injury (AKI) is not well described despite its importance for prognostication and informed decision-making on life-sustaining therapies. In this study, we aim to describe the epidemiology of frailty in a cohort of older critically ill patients with severe AKI, the outcomes of patients with pre-existing frailty before AKI and the factors associated with a worsening frailty status among survivors. METHODS: This was a secondary analysis of a prospective multicentre observational study that enrolled older (age > 65 years) critically ill patients with AKI. The clinical frailty scale (CFS) score was captured at baseline, at 6 months and at 12 months among survivors. Frailty was defined as a CFS score of ≥ 5. Demographic, clinical and physiological variables associated with frailty as baseline were described. Multivariable Cox proportional hazard models were constructed to describe the association between frailty and 90-day mortality. Demographic and clinical factors associated with worsening frailty status at 6 months and 12 months were described using multivariable logistic regression analysis and multistate models. RESULTS: Among the 462 patients in our cohort, median (IQR) baseline CFS score was 4 (3-5), with 141 (31%) patients considered frail. Pre-existing frailty was associated with greater hazard of 90-day mortality (59% (n = 83) for frail vs. 31% (n = 100) for non-frail; adjusted hazards ratio [HR] 1.49; 95% CI 1.11-2.01, p = 0.008). At 6 months, 68 patients (28% of survivors) were frail. Of these, 57% (n = 39) were not classified as frail at baseline. Between 6 and 12 months of follow-up, 9 (4% of survivors) patients transitioned from a frail to a not frail status while 10 (4% of survivors) patients became frail and 11 (5% of survivors) patients died. In multivariable analysis, age was independently associated with worsening CFS score from baseline to 6 months (adjusted odds ratio [OR] 1.08; 95% CI 1.03-1.13, p = 0.003). CONCLUSIONS: Pre-existing frailty is an independent risk factor for mortality among older critically ill patients with severe AKI. A substantial proportion of survivors experience declining function and worsened frailty status within one year.

A proposed algorithm for combining transcranial Doppler ultrasound monitoring with cerebral and somatic oximetry: a case report.

PURPOSE: Transcranial Doppler (TCD) ultrasound is a non-invasive monitor of cerebral blood velocity that can be used intraoperatively. The purpose of this report is to describe how different patterns seen on TCD can help identify the cause of cerebral desaturation when near-infrared spectroscopy (NIRS) oximetry is used concomitantly. CLINICAL FEATURES: A 69-yr-old male patient undergoing coronary revascularisation and aortic valve replacement developed perioperative complications that were detected using a combination of transtemporal TCD of the middle cerebral artery along with cerebral and somatic NIRS. Initial brain desaturation was secondary to hypocapnia during which TCD-derived blood velocity and somatic NIRS values remained unchanged. After the procedure, a second episode of brain desaturation occurred secondary to a technical issue with the aortic valve prosthesis requiring a return to cardiopulmonary bypass (CPB); there were no high-intensity transient signals (HITS) on TCD. Brain desaturation occurred a third time following the second attempt to separate from CPB at which time TCD detected a significant amount of HITS suggesting air emboli that were associated with acute right ventricular dysfunction; there was also a reduction in somatic NIRS. CONCLUSIONS: Combining TCD with cerebral NIRS allows for the rapid identification of three different mechanisms of brain desaturation. An algorithm is proposed to help identify the origin of NIRS cerebral desaturation. Prospective clinical trials are needed to investigate potential benefits of multimodal brain monitoring and its impact on short and/or long-term clinical outcomes.

RéSUMé: OBJECTIF: L'échographie par Doppler transcrânien (DTC) est un moniteur non invasif de la vélocité sanguine cérébrale qui peut être utilisé en période peropératoire. L'objectif de ce compte rendu est de décrire comment différents tracés observés sur le DTC peuvent aider l'anesthésiologiste à identifier la cause de la désaturation cérébrale lorsque l'oxymétrie par spectroscopie proche infrarouge (SPIR) est utilisée de manière concomitante. ÉLéMENTS CLINIQUES: Un homme de 69 ans subissant une revascularisation coronarienne et un remplacement de valve aortique a présenté des complications périopératoires détectées grâce à la combinaison d'un DTC trans-temporal de l'artère cérébrale moyenne et d'une SPIR cérébrale et somatique. La désaturation cérébrale initiale était secondaire à une hypocapnie, pendant laquelle la vélocité sanguine dérivée du DTC et les valeurs de SPIR somatique sont demeurées inchangées. Après l'intervention, un deuxième épisode de désaturation cérébrale est survenu suite à un problème technique avec la prothèse de valve aortique, nécessitant un retour sous circulation extracorporelle (CEC); il n'y avait pas de signaux transitoires de haute intensité (HITS) sur le DTC. Il y a eu un troisième épisode de désaturation cérébrale suite à la deuxième tentative de sevrage de la CEC; à ce moment-là, le DTC a détecté une quantité significative de HITS, suggérant des embolies gazeuses associées à une insuffisance ventriculaire droite aiguë; une réduction de la SPIR somatique a également été observée. CONCLUSION: La combinaison du DTC à la SPIR cérébrale a permis d'identifier trois différents mécanismes de désaturation cérébrale. Un algorithme est proposé pour aider le clinicien à déterminer l'origine de la désaturation cérébrale sur la SPIR. Des études cliniques prospectives sont nécessaires afin d'explorer les avantages potentiels d'un monitorage cérébral multimodal et son impact sur les devenirs cliniques à court et à long terme.

COVID-19 Outbreak in an Urban Hemodialysis Unit.

RATIONALE & OBJECTIVE: Hemodialysis patients are at increased risk for coronavirus disease 2019 (COVID-19) transmission due in part to difficulty maintaining physical distancing. Our hemodialysis unit experienced a COVID-19 outbreak despite following symptom-based screening guidelines. We describe the course of the COVID-19 outbreak and the infection control measures taken for mitigation. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 237 maintenance hemodialysis patients and 93 hemodialysis staff at a single hemodialysis center in Toronto, Canada. EXPOSURE: Universal screening of patients and staff for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). OUTCOMES: The primary outcome was detection of SARS-CoV-2 in nasopharyngeal samples from patients and staff using reverse transcriptase-polymerase chain reaction (RT-PCR). ANALYTICAL APPROACH: Descriptive statistics were used for clinical characteristics and the primary outcome. RESULTS: 11 of 237 (4.6%) hemodialysis patients and 11 of 93 (12%) staff members had a positive RT-PCR test result for SARS-CoV-2. Among individuals testing positive, 12 of 22 (55%) were asymptomatic at time of testing and 7 of 22 (32%) were asymptomatic for the duration of follow-up. One patient was hospitalized at the time of SARS-CoV-2 infection and 4 additional patients with positive test results were subsequently hospitalized. 2 (18%) patients required admission to the intensive care unit. After 30 days' follow-up, no patients had died or required mechanical ventilation. No hemodialysis staff required hospitalization. Universal droplet and contact precautions were implemented during the outbreak. Hemodialysis staff with SARS-CoV-2 infection were placed on home quarantine regardless of symptom status. Patients with SARS-CoV-2 infection, including asymptomatic individuals, were treated with droplet and contact precautions until confirmation of negative SARS-CoV-2 RT-PCR test results. Analysis of the outbreak identified 2 index cases with subsequent nosocomial transmission within the dialysis unit and in shared shuttle buses to the hemodialysis unit. LIMITATIONS: Single-center study. CONCLUSIONS: Universal SARS-CoV-2 testing and universal droplet and contact precautions in the setting of an outbreak appeared to be effective in preventing further transmission.

The Frequency of Routine Blood Sampling and Patient Outcomes Among Maintenance Hemodialysis Recipients.

RATIONALE & OBJECTIVE: Surveillance blood work is routinely performed in maintenance hemodialysis (HD) recipients. Although more frequent blood testing may confer better outcomes, there is little evidence to support any particular monitoring interval. STUDY DESIGN: Retrospective population-based cohort study. SETTING & PARTICIPANTS: All prevalent HD recipients in Ontario, Canada, as of April 1, 2011, and a cohort of incident patients commencing maintenance HD in Ontario, Canada, between April 1, 2011, and March 31, 2016. EXPOSURE: Frequency of surveillance blood work, monthly versus every 6 weeks. OUTCOMES: The primary outcome was all-cause mortality. Secondary outcomes were major adverse cardiovascular events, all-cause hospitalization, and episodes of hyperkalemia. ANALYTICAL APPROACH: Cox proportional hazards with adjustment for demographic and clinical characteristics was used to evaluate the association between blood testing frequency and all-cause mortality. Secondary outcomes were evaluated using the Andersen-Gill extension of the Cox model to allow for potential recurrent events. RESULTS: 7,454 prevalent patients received care at 17 HD programs with monthly blood sampling protocols (n=5,335 patients) and at 8 programs with blood sampling every 6 weeks (n=2,119 patients). More frequent monitoring was not associated with a lower risk for all-cause mortality compared to blood sampling every 6 weeks (adjusted HR, 1.16; 95% CI, 0.99-1.38). Monthly monitoring was not associated with a lower risk for any of the secondary outcomes. Results were consistent among incident HD recipients. LIMITATIONS: Unmeasured confounding; limited data for center practices unrelated to blood sampling frequency; no information on frequency of unscheduled blood work performed outside the prescribed sampling interval. CONCLUSIONS: Monthly routine blood testing in HD recipients was not associated with a lower risk for death, cardiovascular events, or hospitalizations as compared with testing every 6 weeks. Given the health resource implications, the frequency of routine blood sampling in HD recipients deserves careful reassessment.

Lymphocytopenia During Hospitalization for Acute Heart Failure and Its Relationship With Portal Congestion and Right Ventricular Function.

BACKGROUND: Lymphocytopenia is associated with mortality in acute heart failure (AHF), and portal congestion has been suggested to play a role in leukocyte distribution. The associations between lymphocytopenia and ultrasound surrogates for portal congestion have never been studied. We aimed to characterize the determinants of lymphocytopenia, explore the associations between lymphocytopenia and portal congestion, and explore the relationships between lymphocytopenia and outcomes in AHF. METHODS AND RESULTS: Patients were compared according to tertiles of lymphocyte count (very low, <0.87 × 109/L; low, 0.87-1.2 × 109/L; or normal, >1.2 × 109/L). One hundred three patients with AHF were prospectively assessed at baseline and discharge. At baseline, 69% of patients had a lymphocyte count below the normal range. Patients with baseline very low lymphocyte count were older, had more advanced disease and higher portal vein pulsatility index when compared with those in the higher tertiles. Very low lymphocyte count at baseline was associated with age (odds ratio (OR) 1.098), portal vein pulsatility index (OR, 1.026), and tricuspid annular plane systolic excursion (OR, 0.865, all P < .05). The portal vein pulsatility index was the most powerful determinant of lymphocytopenia at discharge (OR 1.033, P < .05). In a Cox model, lymphocytopenia at discharge was associated with mortality (hazard ratio 4.796, P < .05). CONCLUSIONS: In AHF, lymphocytopenia is associated with ultrasound surrogates for portal congestion and right ventricular dysfunction. Whether these associations depict a potent pathophysiologic pathway or whether they only reflect a more advanced disease remains uncertain.

Preliminary Experience Using Diastolic Right Ventricular Pressure Gradient Monitoring in Cardiac Surgery.

OBJECTIVES: Right ventricular (RV) dysfunction in cardiac surgery is associated with increased mortality and morbidity and difficult separation from cardiopulmonary bypass (DSB). The primary objective of the present study was to describe the prevalence and characteristics of patients with abnormal RV diastolic pressure gradient (PG). The secondary objective was to explore the association among abnormal diastolic PG and DSB, postoperative complications, high central venous pressure (CVP), and high RV end-diastolic pressure (RVEDP). DESIGN: Retrospective and prospective validation study. SETTING: Tertiary care cardiac institute. PARTICIPANTS: Cardiac surgical patients (n=374) from a retrospective analysis (n=259) and a prospective validation group (n=115). INTERVENTION: RV pressure waveforms were obtained using a pulmonary artery catheter with a pacing port opened at 19 cm distal to the tip of the catheter. Abnormal RV diastolic PG was defined as >4 mmHg. Both elevated RVEDP and high CVP were defined as >16 mmHg. MEASUREMENTS AND MAIN RESULTS: From the retrospective and validation cohorts, 42.5% and 48% of the patients had abnormal RV diastolic PG before cardiac surgery, respectively. Abnormal RV diastolic PG before cardiac surgery was associated with higher EuroSCORE II (odds ratio 2.29 [1.10-4.80] v 1.62 [1.10-3.04]; p = 0.041), abnormal hepatic venous flow (45% v 29%; p = 0.038), higher body mass index (28.9 [25.5-32.5] v 27.0 [24.9-30.5]; p = 0.022), pulmonary hypertension (48% v 37%; p = 0.005), and more frequent DSB (32% v 19%; p = 0.023). However, RV diastolic PG was not an independent predictor of DSB, whereas RVEDP (odds ratio 1.67 [1.09-2.55]; p = 0.018) was independently associated with DSB. In addition, RV pressure monitoring indices were superior to CVP in predicting DSB. CONCLUSION: Abnormal RV diastolic PG is common before cardiac surgery and is associated with a higher proportion of known preoperative risk factors. However, an abnormal RV diastolic PG gradient is not an independent predictor of DSB in contrast to RVEDP.