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Abstract Echocardiography has gained wide acceptance among intensive care physicians during the last 15 years. The lack of accredited formation, the long learning curve required and the excessive structural orientation of the present algorithms to evaluate hemodynamically unstable patients hampers its daily use in the intensive care unit. The aim of this article is to show 4 cases where the use of our simple algorithm based on VTI, was crucial. Subsequently, to explain the benefit of using the proposed algorithm with a more functional perspective, as a means for clinical decision-making. A simple algorithm based on left ventricle outflow tract velocity–time integral measurement for a functional hemodynamic monitoring on patients suffering hemodynamic shock or instability is proposed by Spanish Critical Care Ultrasound Network Group. This algorithm considers perfusion and congestion variables. Its simplicity might be useful for guiding physicians in their daily decision-making managing critically ill patients in hemodynamic shock.

Background: Contrast-induced acute kidney injury (CI-AKI) is a frequent complication of coronary interventions associated with an increased risk of mortality and morbidity. The optimal intravenous hydration strategy to prevent CI-AKI is not well-established. The primary objective is to determine if a tailored hydration strategy reduces the risk of CI-AKI and of major adverse cardiovascular events (MACE) in patients undergoing coronary angiography compared with a nontailored hydration strategy., Methods: A study-level meta-analysis of randomized controlled trials comparing tailored versus nontailored hydration strategies for the prevention of CI-AKI (primary outcome) and of MACE (main secondary outcome) in patients undergoing coronary angiography for any indication was performed. Tailored hydration was defined as the administration of intravenous fluids based on patient-specific parameters other than weight only., Results: A total of 13 studies were included (n = 4,458 participants). The overall risk of bias was moderate. A tailored strategy was associated with a significant reduction in the risk of CI-AKI (RR = 0.56, 95% CI, [0.46-0.69], P < .00001; I 2 = 26%), and of MACE (RR = 0.57, 95% CI, [0.42-0.78], P = .0005; I 2 = 12%). A tailored hydration strategy was not associated with a significant reduction in the other prespecified secondary outcomes, except for all-cause mortality (RR = 0.57, 95% CI, [0.35, 0.94], P = .03; I 2 = 0%). The impact of a tailored strategy on the primary outcome was consistent in sensitivity analyses., Conclusion: These results suggest that tailored hydration is superior to nontailored hydration in reducing the risk of CI-AKI and MACE in patients undergoing coronary angiography. Future trials are required to identify the optimal tailored hydration strategy., Competing Interests: Conflicts of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Dr. Marquis-Gravel reports consulting fees or honoraria from HLS Therapeutics, Bayer, Boston Scientific, Novartis, Servier, JAMP Pharma, Pharmascience, KYE, Amgen, and CSI. He is a Junior 1 Clinical Research Scholar of the Fonds de Recherche du Québec- Santé, and the principal investigator of the NEPTUNE trial., (Copyright © 2025 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Fluid balance gap (FBgap-prescribed vs. achieved) is associated with hospital mortality. Downtime is an important quality indicator for the delivery of continuous renal replacement therapy (CRRT). We examined the association of CRRT downtime with FBgap and clinical outcomes including mortality., Methods: This is a retrospective cohort study of critically ill adults receiving CRRT utilizing both electronic health records (EHR) and CRRT machine data. FBgap was calculated as achieved minus prescribed fluid balance. Downtime, or percent treatment time loss (%TTL), was defined as CRRT downtime in relation to the total CRRT time. Data collection stopped upon transition to intermittent hemodialysis when applicable. Linear and logistic regression models were used to analyze the association of %TTL with FBgap and hospital mortality, respectively. Covariates included demographics, Sequential Organ Failure Assessment (SOFA) score at CRRT initiation, use of organ support devices, and the interaction between %TTL and machine alarms., Results: We included 3630 CRRT patient-days from 500 patients with a median age of 59.5 years (IQR 50-67). Patients had a median SOFA score at CRRT initiation of 13 (IQR 10-16). Median %TTL was 8.1% (IQR 4.3-12.5) and median FBgap was 17.4 mL/kg/day (IQR 8.2-30.4). In adjusted models, there was a significant positive relationship between FBgap and %TTL only in the subgroup with higher alarm frequency (6 + alarms per CRRT-day) (β = 0.87 per 1% increase, 95%CI 0.48-1.26). No association was found in the subgroups with lower alarm frequency (0-2 and 3-5 alarms). There was no statistical evidence for an association between %TTL and hospital mortality in the adjusted model with the interaction term of alarm frequency., Conclusions: In critically ill adult patients undergoing CRRT, %TTL was associated with FBgap only in the subgroup with higher alarm frequency, but not in the other subgroups with lower alarms. No association between %TTL and mortality was observed. More frequent alarms, possibly indicating unexpected downtime, may suggest compromised CRRT delivery and could negatively impact FBgap., Competing Interests: Declarations. Ethics approval and consent to participate: The study was approved by the Institutional Review Board (IRB) from the University of Kentucky (17-0444-P1G). Given the observational nature of this investigation, informed consent was waived by the IRB. Consent for publication: Not applicable. Competing interests: The authors declare that they have no competing interests., (© 2024. The Author(s).)

Background: Patients who experienced acute kidney injury (AKI) may benefit from dedicated care following hospital discharge. Most of these patients will be followed by primary care providers. There is a lack of data on current practices and comfort for these care providers when offering post-AKI care., Objective: We surveyed nurse practitioners and family physicians to assess their awareness, perceptions, practice patterns and comfort regarding post-AKI care., Design/setting: We distributed a web-based self-administered survey among clinicians from the Province of Quebec. We asked about their awareness and perceptions on how AKI should be disclosed and followed, the barriers encountered regarding the process of care following hospital discharge, and their level of comfort and expertise in offering dedicated post-AKI care. The survey integrated direct and scenario-based questions and was conducted from December 2022 to April 2023., Participants: We distributed the survey to practicing family physicians and nurse practitioners through the mailing list of the Fédération des Médecins Omnipraticiens du Québec , and the Association des infirmières praticiennes spécialisées du Québec , respectively. No incentives were provided., Methods: We conducted descriptive analyses and used chi-squared analysis to compare responses between family physicians and nurse practitioners and between hospital-based and cabinet-based practice., Results: The survey was opened by 779 potential participants. Of these, the response rate was 9% (70/779). Most participants were family physicians (79%) and dedicated 70% (±32) of their time in community outpatient clinics. Participants reported that 59% (±20) of all patients seen daily had at least 1 risk factor for AKI, whereas they estimated that 21% (±12) of recently discharged patients suffered from an AKI episode. The lack of awareness by the patient and lack of details on the discharge summary were the barriers most frequently reported impacting the overall process of care at follow-up. Most nurse practitioners (60%) and 33% of family physicians reported at least some levels of discomfort and lack of expertise when offering post-AKI., Limitations: The generalizability of our study is limited by its response rate. However, this is comparable with typical response rates seen in electronic surveys. The distribution was limited to a single province of Canada., Conclusions: We reported significant barriers regarding the hospital-to-community transition of care in patients who experienced AKI and the suboptimal comfort and expertise of primary care providers when offering dedicated post-AKI care. This reflects the need to improve communication, collaboration, and AKI training with primary care providers., Competing Interests: The author(s) declared the following potential conflicts of interest: J.-M.C. reports Board Advisory for GlaxoSmithKline, received research funding from Bayer, and is supported by the Centre de recherche de l’Université de Montréal and the Université de Montréal Faculty of Medicine. J.B. declares no conflict of interest. L.H. declares no conflict of interest. W.B.-S. reports research funding from AstraZeneca and Bayer and is supported by Fonds de recherche en santé du Québec and KRESCENT program (Kidney Foundation of Canada). The authors declare no conflicts of interest with respect to this research., (© The Author(s) 2024.)

Background: The Abdominal Compartment Society (WSACS) established consensus definitions and recommendations for the management of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) in 2006, and they were last updated in 2013. The WSACS conducted an international survey between 2022 and 2023 to seek the agreement of healthcare practitioners (HCPs) worldwide on current and new candidate statements that may be used for future guidelines., Methods: A self-administered, online cross-sectional survey was conducted under the auspices of the WSACS to assess the level of agreement among HCPs over current and new candidate statements. The survey, distributed electronically worldwide, collected agreement or disagreement with statements on the measurement of intra-abdominal pressure (IAP), pathophysiology, definitions, and management of IAH/ACS. Statistical analysis assessed agreement levels, expressed in percentages, on statements among respondents, and comparisons between groups were performed according to the respondent's education status, base specialty, duration of work experience, role (intensivist vs non-intensivist) and involvement in previous guidelines. Agreement was considered to be reached when 80% or more of the respondents agreed with a particular statement., Results: A total of 1042 respondents from 102 countries, predominantly physicians (73%), of whom 48% were intensivists, participated. Only 59% of HCPs were aware of the 2013 WSACS guidelines, and 41% incorporated them into practice. Despite agreement in most statements, significant variability existed. Notably, agreement was not reached on four new candidate statements: "normal intra-abdominal pressure (IAP) is 10 mmHg in critically ill adults" (77%), "clinical assessment and estimation of IAP is inaccurate" (65.2%), "intragastric can be an alternative to the intravesical route for IAP measurement" (70.4%), and "measurement of IAP should be repeated in the resting position after measurement in a supine position" (71.9%). The survey elucidated nuances in clinical practice and highlighted areas for further education and standardization., Conclusion: More than ten years after the last published guidelines, this worldwide cross-sectional survey collected feedback and evaluated the level of agreement with current recommendations and new candidate statements. This will inform the consensus process for future guideline development., Competing Interests: Declarations. Ethics approval and consent to participate: The international survey was initiated by the Abdominal Compartment Society (WSACS,  www.wsacs.org ), and conducted with voluntary participation of healthcare professionals. Protection of participants’ data was ensured under the General Data Protection Regulation (GDPR) of the European Union. The study was designed as a low-risk research project, focusing on personal opinion data collection through an online anonymous survey. The survey methodology and subsequent data analysis were conducted following the ethical principles outlined in the Declaration of Helsinki, which emphasizes respect for individuals, their right to make informed decisions, and the confidentiality of their personal data. Consent was implied upon completion of the survey for participation, anonymized data processing, and publication of the results. Competing interests: ARB received speaker or consultancy fee from Nutricia and VIPUN Medical and is holding a grant from the Estonian Research Council (Grant number PRG1255). MLNGM is a member of the medical advisory Board of Pulsion Medical Systems (fully part of the Getinge group), Serenno Medical, Potrero Medical, Sentinel Medical and Baxter. He consults for BBraun, Becton Dickinson, ConvaTec, Spiegelberg, Medtronic, MedCaptain, and Holtech Medical and receives speaker fees from PeerVoice. He holds stock options for Serenno and Potrero. He is a cofounder and President of the International Fluid Academy (IFA). The IFA ( http://www.fluidacademy.org ) is integrated within the not-for-profit charitable organization iMERiT, International Medical Education and Research Initiative, under Belgian law. The remaining authors have no conflicts of interest., (© 2024. The Author(s).)

There has been a significant interest in venous congestion in recent years, among which the VExUS score has been prominent, both in clinical practice and research efforts. We have noted some recurrent misconceptions among clinicians which are also reflected in certain research efforts. Notably, the misguided attempt to correlate VExUS to volume status, which is only one of the factors influencing it, as well as attempts to re-interpret VExUS in the context of certain pathologies, which reflects a fundamental misunderstanding of its circulatory perspective. In this article we review the physiological basis of the VExUS assessment as a measure and marker of venous congestion from the organs' standpoint and its role as part of the emerging concept of fluid tolerance, in hopes to address these misconceptions for clinicians and for important further studies., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: None., (© 2024. The Author(s).)

The ultrasound backscatter coefficient is a frequency-dependent quantity intrinsic to biological tissues that can be recovered from backscattered radiofrequency signals, granted acquisitions on a reference phantom are available under the same system's settings. A phantom-free backscatter coefficient estimation method is proposed based on Gaussian-shaped approximation of the point spread function (electronics and piezoelectric characteristics of the scanner's probe) and the effective medium theory combined with the structure factor model, albeit the proposed approach is amenable to other models. Meanwhile, the total attenuation due to intervening tissues is refined from its theoretical value, which is based on reported average behaviors of tissues, while allowing correction for diffraction due to the probe's geometry. The reference phantom method adapted to a similar approach except for the Gaussian approximation is also presented. The proposed phantom-free and reference phantom methods were compared on ten COVID-19 positive patients and twelve control subjects with measures on femoral veins and arteries. In this context, red blood cells are viewed as scatterers that form aggregates increasing the backscatter under the COVID-19 inflammatory condition. The considered model comprises five parameters, including the mean aggregate size estimated according to polydispersity of aggregates' radii, and anisotropy of their shape. The mean aggregate size over the two proposed methods presented an intraclass correlation coefficient of 0.964 for consistency. The aggregate size presented a significant difference between the two groups with either two methods, despite the confounding effect of the maximum Doppler velocity within the blood vessel and its diameter.

Point-of-care ultrasonography (POCUS) has rapidly evolved from a niche technology to an indispensable tool across medical specialties, including nephrology. This evolution is driven by advancements in technology and the visionary efforts of clinicians in emergency medicine and beyond. Recognizing its potential, medical schools are increasingly integrating POCUS into training curricula, emphasizing its role in enhancing diagnostic accuracy and patient care. Despite these advancements, barriers such as limited faculty expertise and 'lack of' standardized guidelines hinder widespread adoption and regulation. The International Alliance for POCUS in Nephrology (IAPN), through this position statement, aims to guide nephrologists in harnessing the diagnostic power of POCUS responsibly and effectively. By outlining core competencies, recommending training modalities and advocating for robust quality assurance measures, we envision a future where POCUS enhances nephrology practice globally, ensuring optimal patient outcomes through informed, evidence-based decision-making. International collaboration and education are essential to overcome current challenges and realize the full potential of POCUS in nephrology and beyond., Competing Interests: S.A. is supported by ECHONous with a research grant in kind. The remainder of the authors declare no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.)

Background: During cardiac surgery, right ventricular outflow tract obstruction (RVOTO) is defined as an instantaneous pressure difference ≥ 6 mm Hg between right ventricular systolic pressure (RVSP) and pulmonary artery systolic pressure (PASP), for ≥ 5 minutes. Risk factors for RVOTO remain poorly understood. This cohort study was designed to evaluate the incidence, characteristics, and outcomes of the patients who experienced RVOTO., Methods: Instantaneous pressure difference between RVSP and PASP was measured by means of a pulmonary artery catheter with a right ventricular port during cardiac surgery from a retrospective (n = 295) and a prospective (n = 105) cohort., Results: From the retrospective and prospective cohorts, respectively, incidence of RVOTO was 30.2% and 36.2% before cardiopulmonary bypass (CPB) initiation and 43.7% and 47.6% after CPB separation. Before CPB initiation, patients with RVOTO had higher cardiac output (4.2 ± 1.5 vs 3.8 ± 1.1 L/min; P = 0.033) and received more inhaled epoprostenol (79% vs 61%; P = 0.005) and inotropes (66% vs 51%; P = 0.016) compared with those without RVOTO. After CPB separation, patients with RVOTO had higher heart rate (62 ± 15 vs 58 ± 13 beats/min; P = 0.011), cardiac output (4.1 ± 1.4 vs 3.7 ± 1.1 L/min; P = 0.003), and CPB duration (90 ± 45 vs 77 ± 30 min, P = 0.014), had lower fluid balance (758 ± 1123 vs 1063 ± 1089 mL; P = 0.021), and were more exposed to intratracheal milrinone (12% vs 4%; P = 0.015) compared with those without RVOTO. The time with persistent organ dysfunction (T POD ) at 28 days after surgery was similar among patients who had an RVOTO event, before CPB initiation or after CPB separation, compared with those who did not., Conclusions: RVOTO is common in cardiac surgery. However, it is not associated with longer T POD ., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

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., Competing Interests: Declaration of competing interest Dr. Denault received a research grant from Edwards Lifesciences. He is a consultant for CAE Healthcare and on the speakers bureau for Masimo. Daniel Scherb, Kevin Moses, and Cristhian Potes are engineers from Edwards Lifesciences, Irvine, CA., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: During cardiac surgery, transcranial Doppler (TCD) represents a non-invasive modality that allows measurement of red blood cell flow velocities in the cerebral arteries. TCD can also be used to detect and monitor embolic material in the cerebral circulation. Detection of microemboli is reported as a high intensity transient signal (HITS). The importance of cerebral microemboli during cardiac surgery has been linked to the increased incidence of postoperative renal failure, right ventricular dysfunction, and hemodynamic instability. The objective of this study is to determine whether the embolic load is associated with hemodynamic instability during cardiopulmonary bypass (CPB) separation and postoperative complications., Methods: A retrospective single-centre cohort study of 354 patients undergoing cardiac surgery between December 2015 and March 2020 was conducted. Patients were divided in tertiles, where 117 patients had a low quantity of embolic material (LEM), 119 patients have a medium quantity of microemboli (MEM) and 118 patients who have a high quantity of embolic material (HEM). The primary endpoint was a difficult CPB separation. Multivariate logistic regression was used to determine the potential association between a difficult CPB separation and the number of embolic materials., Results: Patients who had a difficult CPB separation had more HITS compared to patients who had a successful CPB separation (p < 0.001). In the multivariate analysis, patients with MEM decreased their odds of having a difficult CPB weaning compared to patients in the HEM group (OR = 0.253, CI 0.111-0.593; p = 0.001). In the postoperative period patients in the HEM group have a higher Time of Persistent Organ Dysfunction (TPOD), a longer stay in the ICU, a longer duration under vasopressor drugs and a higher mortality rate compared to those in the MEM and LEM groups., Conclusion: The result of this study suggests that a high quantity of cerebral embolic material increases the odds of having a difficult CPB separation. Also, it seems to be associated to more complex surgery, a longer CPB time, a higher TPOD and a longer stay in the ICU. Six out of eight patients who died in this cohort were in the HEM group., (© 2024. The Author(s).)

Introduction: Organ congestion may be a mediator of adverse outcomes in critically ill patients with severe acute kidney injury (AKI). The presence of abnormal venous Doppler waveforms could identify patients with clinically significant organ congestion who may benefit from a decongestive strategy., Methods: This prospective multicenter cohort study enrolled patients with severe AKI defined as Kidney Disease: Improving Global Outcomes stage 2 or higher. Patients were not eligible if they received renal replacement therapy (RRT) for more than 72 hours at the time of screening. Participants underwent serial Doppler ultrasound examinations of the portal, hepatic and intrarenal veins during the week following enrolment. We calculated the venous excess ultrasound (VExUS) score based on these data. The primary outcome studied was major adverse kidney events at 30 days (MAKE30) defined as death, RRT dependence, or a persistent decrease in kidney function., Results: A total of 125 patients were included for whom 291 ultrasound assessments were performed. Severely abnormal venous waveforms were documented in 14.4% of portal vein assessments, 6.5% of intrarenal venous assessments, and 14.4% of hepatic vein assessments. The individual ultrasound markers were not associated with MAKE30. The VExUS score (grade 0-1: reference; grade 2: adjusted hazard ratio [aHR]: 4.03, confidence interval [CI]: 1.81-8.99; grade 3: aHR: 2.70, CI: 1.10-6.65; P  = 0.03), as well as severely abnormal portal, hepatic and intrarenal vein Doppler were each independently associated with mortality., Conclusion: Although not significantly associated with MAKE30, venous Doppler abnormalities suggestive of venous congestion were associated with higher mortality in critically ill patients with severe AKI., (© 2023 International Society of Nephrology. Published by Elsevier Inc.)

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., (© 2023. Canadian Anesthesiologists' Society.)

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., (© 2023 The Authors. Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.)

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. (β = -5.693, r 2  = 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., Competing Interests: Conflict of Interest None., (Copyright © 2023. Published by Elsevier Inc.)

Introduction: Venous congestion is a pathophysiological state where high venous pressures cause organ oedema and dysfunction. Venous congestion is associated with worse outcomes, particularly acute kidney injury (AKI), for critically ill patients. Venous congestion can be measured by Doppler ultrasound at the bedside through interrogation of the inferior vena cava (IVC), hepatic vein (HV), portal vein (PV) and intrarenal veins (IRV). The objective of this study is to quantify the association between Doppler identified venous congestion and the need for renal replacement therapy (RRT) or death for patients with septic shock., Methods and Analysis: This study is a prespecified substudy of the ANDROMEDA-SHOCK 2 (AS-2) randomised control trial (RCT) assessing haemodynamic resuscitation in septic shock and will enrol at least 350 patients across multiple sites. We will include adult patients within 4 hours of fulfilling septic shock definition according to Sepsis-3 consensus conference. Using Doppler ultrasound, physicians will interrogate the IVC, HV, PV and IRV 6-12 hours after randomisation. Study investigators will provide web-based educational sessions to ultrasound operators and adjudicate image acquisition and interpretation. The primary outcome will be RRT or death within 28 days of septic shock. We will assess the hazard of RRT or death as a function of venous congestion using a Cox proportional hazards model. Sub-distribution HRs will describe the hazard of RRT given the competing risk of death., Ethics and Dissemination: We obtained ethics approval for the AS-2 RCT, including this observational substudy, from local ethics boards at all participating sites. We will report the findings of this study through open-access publication, presentation at international conferences, a coordinated dissemination strategy by investigators through social media, and an open-access workshop series in multiple languages., Trial Registration Number: NCT05057611., Competing Interests: Competing interests: AD has the following disclosures, however, none are relevant to this current research: CAE-Healthcare (2010) speaker bureau, (2020) KOL speaker bureau, Masimo (2017) speaker bureau, Edwards (2019) research (equipment grant) and supported by the Richard I. Kaufman Endowment Fund in Anesthesia and Critical Care (2015). EA has the following disclosures, however, it is not relevant or discussed in this current research: Speaker honoraria from EchoNous. The remaining authors have relevant conflict of interest to declare., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: In critically ill patients receiving KRT, high ultrafiltration rates and persistent fluid accumulation are associated with adverse outcomes. The purpose of this international survey was to evaluate current practices and evidence gaps related to fluid removal with KRT in critically ill patients., Methods: This was a multinational, web-based survey distributed by seven networks comprising nephrologists and intensivists. Physicians involved in the care of critically ill patients were invited to complete a 39-question survey about fluid management practices on KRT. The survey was distributed from September 2021 to December 2021., Results: There were 757 respondents from 96 countries (response rate of 65%). Most respondents practiced adult medicine (89%) and worked in an academic center (69%). The majority (91%) reported aiming for a 0.5- to 2-L negative fluid balance per day when fluid removal is indicated, although there was important variability in what respondents considered a safe maximal target. Intensivists were more likely than nephrologists to use adjunct volume status assessment methods ( i.e. , ultrasound, hemodynamic markers, and intra-abdominal pressure), while nephrologists were more likely to deploy cointerventions aimed at improving tolerance to fluid removal ( i.e. , osmotic agents and low-temperature dialysate). There was a broad consensus that rapid decongestion should be prioritized when fluid accumulation is present, but the prevention of hypotension was also reported as a competing priority. A majority (77%) agreed that performing trials that compare fluid management strategies would be ethical and clinically relevant., Conclusions: We have identified multiple areas of variability in current practice of fluid management for patients receiving KRT. Most nephrologists and intensivists agreed that several knowledge gaps related to fluid removal strategies should be investigated in future randomized controlled trials., (Copyright © 2023 by the American Society of Nephrology.)

Objective: To identify potentially modifiable risk factors related to prolonged cardiovascular pharmacological support after weaning from cardiopulmonary bypass (CPB)., Methods: This is a secondary analysis of two prospective cohort study in a specialized cardiac surgery institution in adult patients undergoing cardiac surgery with the use of CPB between August 2016 and July 2017. Prolonged cardiovascular pharmacological support was defined by the need for at least one vasopressor or one inotropic agent 24 hours after separation from CPB. Risk factors were identified among baseline characteristics and peri-operative events through multivariable logistic regression., Results: A total of 247 patients were included and 98 (39.7%) developed prolonged pharmacological support. In multivariable analysis, left ventricular ejection fraction ≤ 30% (OR 9.52, 95% confidence interval (CI) 1.14; 79.25), elevated systolic pulmonary artery pressure (sPAP) > 30 and ≤ 55 mmHg (moderate) (OR 2.52, CI 1.15; 5.52) and sPAP > 55 mmHg (severe) (OR 8.12, CI 2.54; 26.03), as well as cumulative fluid balance in the first 24 hours after surgery (OR 1.76, CI 1.32; 2.33) were independently associated with the development of prolonged pharmacological support., Conclusions: Prolonged cardiovascular pharmacological support is frequent after cardiac surgery on CPB. Severe LV systolic dysfunction, preoperative pulmonary hypertension and postoperative fluid overload are risk factors. Further studies are required to explore if those risk factors could be modified or not., Competing Interests: Dr. Denault is on the Speakers Bureau for CAE Healthcare (2010), Masimo (2017) and Edwards (2019). No other conflict of interest. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2023 Kontar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Emerging data favor central blood pressure (BP) over brachial cuff BP to predict cardiovascular and kidney events, as central BP more closely relates to the true aortic BP. Considering that patients with advanced chronic kidney disease (CKD) are at high cardiovascular risk and can have unreliable brachial cuff BP measurements (due to high arterial stiffness), this population could benefit the most from hypertension management using central BP measurements., Objective: To assess the feasibility and efficacy of targeting central BP as opposed to brachial BP in patients with CKD G4-5., Design: Pragmatic multicentre double-blinded randomized controlled pilot trial., Setting: Seven large academic advanced kidney care clinics across Canada., Patients: A total of 116 adults with CKD G4-5 (estimated glomerular filtration rate [eGFR] < 30 mL/min) and brachial cuff systolic BP between 120 and 160 mm Hg. The key exclusion criteria are 1) ≥ 5 BP drugs, 2) recent acute kidney injury, myocardial infarction, stroke, heart failure or injurious fall, 3) previous kidney replacement therapy., Methods: Double-blind randomization to a central or a brachial cuff systolic BP target (both < 130 mm Hg) as measured by a validated central BP device. The study duration is 12 months with follow-up visits every 2 to 4 months, based on local practice. All other aspects of CKD management are at the discretion of the attending nephrologist., Outcomes: Primary Feasibility : Feasibility of a large-scale trial based on predefined components. Primary Efficacy : Carotid-femoral pulse wave velocity at 12 months. Others : Efficacy (eGFR decline, albuminuria, BP drugs, and quality of life); Events (major adverse cardiovascular events, CKD progression, hospitalization, mortality); Safety (low BP events and acute kidney injury)., Limitations: May be challenging to distinguish whether central BP is truly different from brachial BP to the point of significantly influencing treatment decisions. Therapeutic inertia may be a barrier to successfully completing a randomized trial in a population of CKD G4-5. These 2 aspects will be evaluated in the feasibility assessment of the trial., Conclusion: This is the first trial to evaluate the feasibility and efficacy of using central BP to manage hypertension in advanced CKD, paving the way to a future large-scale trial., Trial Registration: clinicaltrials.gov (NCT05163158)., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

Point-of-care ultrasound has evolved as an invaluable diagnostic modality and procedural guidance tool in the care of critically ill cardiac patients. Beyond focused cardiac ultrasound, additional extracardiac ultrasound modalities may provide important information at the bedside. In addition to new uses of existing modalities, such as pulsed-wave Doppler ultrasound, the development of new applications is fostered by the implementation of additional features in mid-range ultrasound machines commonly acquired for intensive care units, such as tissue elastography, speckle tracking, and contrast-enhanced ultrasound quantification software. This review explores several areas in which ultrasound imaging technology may transform care in the future. First, we review how lung ultrasound in mechanically ventilated patients can enable the personalization of ventilator parameters and help to liberate them from mechanical ventilation. Second, we review the role of venous Doppler in the assessment of organ congestion and how tissue elastography may complement this application. Finally, we explore how contrast-enhanced ultrasound could be used to assess changes in organ perfusion., (Copyright © 2022 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Cellular immune defects associated with suboptimal responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccination in people receiving hemodialysis (HD) are poorly understood. We longitudinally analyze antibody, B cell, CD4 + , and CD8 + T cell vaccine responses in 27 HD patients and 26 low-risk control individuals (CIs). The first two doses elicit weaker B cell and CD8 + T cell responses in HD than in CI, while CD4 + T cell responses are quantitatively similar. In HD, a third dose robustly boosts B cell responses, leads to convergent CD8 + T cell responses, and enhances comparatively more T helper (T H ) immunity. Unsupervised clustering of single-cell features reveals phenotypic and functional shifts over time and between cohorts. The third dose attenuates some features of T H cells in HD (tumor necrosis factor alpha [TNFα]/interleukin [IL]-2 skewing), while others (CCR6, CXCR6, programmed cell death protein 1 [PD-1], and HLA-DR overexpression) persist. Therefore, a third vaccine dose is critical to achieving robust multifaceted immunity in hemodialysis patients, although some distinct T H characteristics endure., Competing Interests: Declaration of interests C.T. serves as a consultant for Merck, Gilead, GSK, AstraZeneca, and Medicago., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

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., Competing Interests: Conflicts of Interest: See Disclosures at the end of the article., (Copyright © 2022 International Anesthesia Research Society.)

Organ congestion from venous hypertension is an important pathophysiological mechanism mediating organ injury in several clinical contexts including critical illness, congestive heart failure and end-stage chronic kidney disease. However, the practical evaluation of venous congestion is often challenging at the bedside because of the limitations of traditional methods. Point-of-care ultrasound (POCUS) enables the clinician to assess venous velocity profiles during the cardiac cycle using Doppler modalities. Venous Doppler profile abnormalities at multiple sites are detected when elevated venous pressure results in hemodynamic changes within the systemic venous circulation. The detection of these abnormal Doppler profiles may identify patients with clinically significant systemic venous congestion. These patients have been reported to be at increased risk of medical complications. Improving the evaluation of venous congestion may lead to individualized treatment and improved patient outcomes. In this review, we describe the physiologic principles necessary to understand venous Doppler assessment. We also propose a nomenclature for the description of venous Doppler profiles. Finally, we provide a narrative review of the current clinical evidence related to use of venous Doppler assessment in various clinical contexts., Competing Interests: Conflict of interest disclosure No author has any relationship with industry to disclose related to this article., (Copyright © 2022 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)

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., (© 2023 The Author(s). Published by S. Karger AG, Basel.)

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., (Copyright © 2022 International Anesthesia Research Society.)

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., (© 2022. The Author(s).)

Introduction: Patients who survive acute kidney injury (AKI) may receive fewer cardioprotective drugs. Our objective was to measure the difference in time to dispensing of evidence-based cardiovascular drugs in patients with a history of myocardial infarction (MI) with and without AKI., Methods: This was a population-based cohort study of patients 66 years of age and older with a history of MI who survived a hospitalization complicated with AKI, propensity-score matched to patients without AKI. The primary outcome was time to outpatient dispensing of an angiotensin-converting enzyme inhibitor (ACEi)/angiotensin II receptor blocker (ARB), statin, or β-blocker within 1 year of hospital discharge., Results: We identified 28,871 patients with AKI, of whom 21,452 were matched 1:1 to patients without AKI. In the matched cohort, mean age was 80 years, 40% were female, and 34% had an MI during the index hospitalization. AKI was associated with less frequent dispensing of all 3 cardiovascular drug classes within 1 year of hospital discharge (subdistribution hazard ratio [sHR], 0.93; 95% confidence interval [CI], 0.91-0.95). This association was most pronounced in patients with stage 2 (sHR, 0.81; 95% CI, 0.75-0.88) and stage 3 (sHR, 0.71; 95% CI, 0.64-0.79) AKI. We observed less frequent dispensing of statins in patients with stage 2 (sHR, 0.87; 95% CI, 0.81-0.92) and stage 3 (sHR, 0.85; 95% CI, 0.78-0.93) AKI and less frequent dispensing of β-blockers in patients with stage 3 AKI (sHR, 0.86; 95% CI, 0.79-0.94)., Conclusion: In patients with a history of MI, survivors of AKI were less likely to receive prescriptions for ACEi/ARB, statins, or β-blockers within 1 year of hospital discharge. This association was most pronounced in patients with stages 2 and 3 AKI., (© 2022 Published by Elsevier Inc. on behalf of the International Society of Nephrology.)

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 (T POD ) 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 T POD (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 T POD . 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., (Copyright © 2022 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Delirium is common in patients undergoing cardiac surgery, and venous congestion has been reported as an important risk factor. We report a 69-year-old patient who developed postoperative delirium in the intensive care unit following aortic valve replacement surgery. The postoperative course was complicated by delirium for which echographic signs of venous congestion on the portal and the renal but also the femoral veins and their resolution correlated with the course of delirium. The use of common femoral vein Doppler as a simple bedside technique to predict and identify congestive delirium has not been reported before., Competing Interests: Conflicts of Interest: See Disclosures at the end of the article., (Copyright © 2022 International Anesthesia Research Society.)

Purpose of Review: Diabetes affects almost a 10th of the Canadian population, and diabetic nephropathy is one of its main complications. It remains a leading cause of kidney failure despite the availability of effective treatments., Sources of Information: The sources of information are iterative discussions between health care professionals and patient partners and literature collected through the search of multiple databases., Methods: Major pitfalls related to optimal diabetic nephropathy care were identified through discussions between patient partners and clinician researchers. We identified underlying factors that were common between pitfalls. We then conducted a narrative review of strategies to overcome them, with a focus on Canadian initiatives., Key Findings: We identified 5 pitfalls along the diabetic nephropathy trajectory, including a delay in diabetes diagnosis, suboptimal glycemic control, delay in the detection of kidney involvement, suboptimal kidney protection, and deficient management of advanced chronic kidney disease. Several innovative care models and approaches have been proposed to address these pitfalls; however, they are not consistently applied. To improve diabetic nephropathy care in Canada, we recommend focusing initiatives on improving awareness of diabetic nephropathy, improving access to timely evidence-based care, fostering inclusive patient-centered care environment, and generating new evidence that supports complex disease management. It is imperative that patients and their families are included at the center of these initiatives., Limitations: This review was limited to research published in peer-reviewed journals. We did not perform a systematic review of the literature; we included articles that were relevant to the major pitfalls identified by our patient partners. Study quality was also not formally assessed. The combination of these factors limits the scope of our conclusions., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)

Background: Cerebral oximetry using near-infrared spectroscopy (NIRS) is used for monitoring cerebral oxygen saturation during cardiac surgery and is correlated with clinical outcomes. Our goal was to explore cerebral and somatic NIRS in liver resections as a predictor of post-operative complications., Methods: Prospective observational and non-interventional study from a tertiary care university hospital including adult patients undergoing liver resection monitored using NIRS at four sites before and during surgery. Those sites were: frontotemporal left and right zones, right thigh, and right arm. Anesthesiologists and surgeons were blinded to oximetry values. Correlations were assessed between baseline oximetry values and cerebro-somatic desaturation load (threshold of 80% from baseline) values with peri-operative events and complications., Results: Ninety patients were distributed equally among gender with a mean age of 59.7 ± 13.1 years. Lower baseline cerebral and/or somatic values were associated with increased risk of delirium, respiratory failure, surgical and renal complications, blood transfusions, and length of stay in the intensive care unit and in the hospital (P < 0.05). The severity of somatic desaturation below 80% was the only parameter associated with blood losses (P = 0.030) and length of hospital stay (P = 0.047)., Conclusions: Cerebral and somatic desaturation does occur in liver resection and can be used simultaneously during liver surgery. Both baseline cerebral and somatic NIRS values are correlated with complications and outcomes. However, thigh desaturation appears more sensitive than cerebral NIRS values in predicting some of these complications.

Critical illness is often complicated by acute kidney injury (AKI). In patients with severe AKI, renal replacement therapy (RRT) is deployed to address metabolic dysfunction and volume excess until kidney function recovers. This review is intended to provide a comprehensive update on key aspects of RRT prescription and delivery to critically ill patients. Recently completed trials have enhanced the evidence base regarding several RRT practices, most notably the timing of RRT initiation and anticoagulation for continuous therapies. Better evidence is still needed to clarify several aspects of care including optimal targets for ultrafiltration and effective strategies for RRT weaning and discontinuation., (© 2022. Springer-Verlag GmbH Germany, part of Springer Nature.)

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., Competing Interests: Conflict of Interest Dr. Denault is a speaker and consultant for CAE Healthcare, speaker for Edwards and Masimo. He received a research grant from Edwards (2019)., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Online hemodiafiltration (HDF) has been increasingly used for improved clearance of middle molecular weight toxins. The impact of this mode of clearance is unknown in critically ill patients. We aimed to determine whether the use of HDF in acute kidney injury (AKI) is associated with lower mortality and improved kidney recovery up to 90 days after initiation of therapy., Methods: Single-center retrospective cohort study using data from 2017 to 2020 of adults with AKI who initiated intermittent renal replacement therapy (IRRT) in the intensive care unit (ICU), using either hemodialysis (HD) or HDF depending on the maintenance status of the water system without regards for patient characteristics. We assessed association with patient-events and session-events using time-dependent Cox models and general estimating equations models, respectively., Results: We included 182 adults with AKI for whom 848 IRRT sessions were performed in the ICU. The 90-day mortality rate was 43 of 182 (24.6%). There was no significant association with the use of HDF and mortality (adjusted hazard ratio [aHR]: 0.85 (0.43; 1.67) P  = 0.64), kidney recovery (aHR: 1.18 (0.76; 1.84) P  = 0.47), or intradialytic hypotension (adjusted odds ratio [aOR]: 0.91 confidence interval [CI]: 0.64-1.28 P  = 0.58). HDF treatment was associated with a lower rate of subsequent vasopressor use (aOR: 0.60 CI: 0.36-0.99 P  = 0.047) and a greater reduction of the neutrophil-to-lymphocyte ratio (NLR) following the first session (-15.0% vs. +5.1%, P  = 0.047) but was also associated with increased risk of filter thrombosis during treatment (aOR: 2.42 CI: 1.67-3.50 P  < 0.001)., Conclusion: The use of HDF in the setting of AKI was not associated with a differential risk of mortality or kidney recovery., (© 2022 International Society of Nephrology. Published by Elsevier Inc.)

Background: The differential diagnosis of acute kidney injury (AKI) episodes is often challenging. Novel AKI biomarkers have shown their utility to improve prognostic prediction and diagnostic assessment in various research populations but their implementation in standard clinical practice is still rarely reported., Objective: To report the differential diagnostic ability and associated clinical utility of the neutrophil gelatinase-associated lipocalin (NGAL) testing in a real-life setting of a heterogeneous AKI population., Design: This is a retrospective cohort study combined with a clinical audit using questionnaires distributed to consultant nephrologists following NGAL results., Setting: The first 250 consecutive patients with a confirmed AKI where an NGAL test (plasma NGAL [pNGAL] or urine NGAL [uNGAL]) was ordered from a large academic center in Montreal, Canada from January 2021 to August 2021., Patients: Patients were classified into 3 groups based on the final AKI etiology category (functional, intrarenal, and postrenal) following definitive adjudication by 2 independent nephrologists., Methods: The ability of plasma NGAL (pNGAL), urine NGAL (uNGAL), and uNGAL-to-creatinine ratio (uNGAL/Cr) to discriminate intrarenal from functional AKI etiologies was compared to standard urine chemistry (FENa) and proteinuria. A logistic regression was used to evaluate the association between intrarenal AKI and increased biomarker levels. The overall clinical utility and appreciation of the NGAL test was evaluated using a questionnaire completed prospectively by the consultant nephrologist at the time of receiving the NGAL result. The NGAL results were prospectively available to clinicians with a median time of 2.9 (1.3-7.4) hours from the initial order., Results: A total of 214 uNGAL and 44 pNGAL were ordered from 100 functional, 139 intrarenal and 11 postrenal AKI episodes after final adjudication. The discriminative ability of FENa (AUC 0.68 [95% CI: 0.61-0.75]) was lower than uNGAL (AUC 0.80 [95% CI: 0.73-0.86]) and uNGAL/Cr (AUC 0.83 [95% CI: 0.77-0.88]) but better than pNGAL (AUC 0.66 [95% CI: 0.48-0.85]). According to consultant nephrologists, the NGAL testing has led to a change in clinical management in 42% of cases., Limitations: Data reported came from a single center and NGAL was reserved for more complex cases, which limits generalizability. No biopsy has been performed for most AKI cases as the final adjudication was based on a retrospective review of the hospitalization episode., Conclusions: Neutrophil gelatinase-associated lipocalin testing can be successfully integrated as part of the diagnostic workup for AKI in clinical practice. The integration of tubular damage biomarkers to functional biomarkers can further improve the differential diagnostic assessment. However, the impact of such biomarkers on AKI management and associated outcomes still needs further validation., Competing Interests: Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: WBS has received honorarium from Baxter. JFC has received honorarium from AstraZeneca. PTM has received consulting/scientific advisory board fees from: AM-Pharma, FAST Biomedical, Renibus Therapeutics and Novartis. The remaining authors have no conflict of interest to declare., (© The Author(s) 2022.)

The utilization of kidney replacement therapies (KRT) for fluid management of patients who are critically ill has significantly increased over the last years. Clinical studies have suggested that both fluid accumulation and high fluid removal rates are associated with adverse outcomes in the critically ill population receiving KRT. Importantly, the ideal indications and/or fluid management strategies that could favorably affect these patients are unknown; however, differentiating clinical scenarios in which effective fluid removal may provide benefit to the patient by avoiding congestive organ injury, compared with other settings in which this intervention may result in harm, is direly needed in the critical care nephrology field. In this review, we describe observational data related to fluid management with KRT, and examine the role of point-of-care ultrasonography as a potential tool that could provide physiologic insights to better individualize decisions related to fluid management through KRT., Competing Interests: W. Beaubien-Souligny reports receiving honoraria from Baxter, and being employed by Centre Hospitalier de l'Université de Montréal (CHUM). J.A. Neyra reports serving as guest editor and on the editorial board of Advances in Chronic Kidney Disease, as section editor of Clinical Nephrology, as guest editor of Critical Care Nephrology, and on the editorial board of Kidney360; having consultancy agreements with Baxter Healthcare Inc., Biomedical Insights, and Leadiant Biosciences; and being employed by the University of Alabama at Birmingham. The remaining author has nothing to disclose., (Copyright © 2022 by the American Society of Nephrology.)

Background: Renin-angiotensin system inhibitors (RASi) are not re-initiated for almost a quarter of patients who suffered acute kidney injury 6 months after discharge. This discontinuation might be partly explained by the nephrotoxicity of these medications, yet they remain of benefit, especially for patients with heart failure., Objective: To determine the factors deemed by clinicians to influence RASi re-initiation and set threshold values for important safety parameters., Design: Three-round modified online Delphi survey., Setting: The study was conducted in Quebec, Canada., Participants: Twenty clinicians from nephrology, intensive care medicine, and internal medicine., Measurements: The factors' importance was rated on 4-point Likert-type scale, ranging from "not important" to "very important" by the panelists., Methods: We conducted a brief literature review to uncover possible influencing factors followed by a 3-round modified Delphi survey to establish a consensus on the importance of these factors., Results: We recruited 20 clinicians (7 nephrologists, 3 internists, and 10 intensive care physicians). We created a list of 25 factors, 15 of which met consensus. Eleven of these factors, including serum creatinine, glomerular filtration rate, and acute kidney injury (AKI) stage, were deemed as important while 4, such as responsibility ambiguity and absence of feedback, were deemed as not important. The majority of the 10 factors which did not meet consensus were related to the clinical setting, such as a pharmacist follow-up and the required time to ensure optimal RASi re-initiation., Limitations: Quebec clinicians' agreement might not reflect the opinion of the rest of Canada. The survey measures clinicians' belief rather than their actual practice., Conclusion: Renin-angiotensin system inhibitors re-initiation is a rather complex concept which encompasses several factors. Our research uncovered some of these factors which may be used to develop guidelines on optimal RASi re-initiation., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)

Background: Hemodialysis patients have faced unique challenges during the COVID-19 pandemic. They face high risk of death if infected and have unavoidable exposure to others when they come to hospital three times weekly for their life-saving treatments. The objective of this study was to gain a better understanding of the scope and magnitude of the effects of the pandemic on the lived experience of patients receiving in-center hemodialysis., Methods: We conducted semi-structured interviews with 22 patients who were undergoing dialysis treatments in five hemodialysis centers in Montreal from November 2020 to May 2021. Interviews were transcribed and then analyzed using thematic content analysis., Results: Most participants reported no negative effects of the COVID-19 pandemic on their hemodialysis care. Several patients had negative feelings related to forced changes in their dialysis schedules, and this was especially pronounced for indigenous patients in a shared living situation. Some patients were concerned about contracting COVID-19, especially during public transportation, whereas others expressed confidence that the physical distancing and screening measures implemented at the hospital would protect them and their loved ones. Some participants reported that masks negatively affected their interactions with health care workers, and for many others, the pandemic was associated with feelings of loneliness. Finally, some respondents reported some positive effects of the pandemic, including use of telemedicine and creating a sense of solidarity., Conclusions: Patients undergoing hemodialysis reported no negative effects on their medical care but faced significant disruptions in their routines and social interactions due to the COVID-19 pandemic. Nevertheless, they showed great resilience in their ability to adapt to the new reality of their hemodialysis treatments. We also show that studies focused on understanding the lived experiences of indigenous patients and patients from different ethnic backgrounds are needed in order reduce inequities in care during public health emergencies., Competing Interests: A. Affdal reports being Scientific Director for the Canadian Journal of Bioethics. W. Beaubien-Souligny reports honoraria from Baxter. D. Blum reports honoraria from AstraZeneca and Otsuka. M.-C. Fortin reports being a member of the ethics committee of Transplant Quebec, the Collège des médecins du Québec, and the Canadian Society of Transplantation and being a member of different committees of the Canadian Blood Services. A.-C. Nadeau-Fredette reports a current scholarship from Fonds de la recherche du Québec en Santé (FRQS). R.S. Suri reports the honoraria from Amgen and Otskuka and an advisory or leadership role for the Canadian Institutes of Health Research Institute of Circulatory and Respiratory Health and the Canadian Society of Nephrology. M. Vasilevsky reports ownership interest in the Bank of America, Birchcliff Energy Ltd., Brookfield Infrastructure Partners, CCL Industries, Inc., CAE, Inc., Canadian National Railway, Cenovus Energy, Eli Lilly, Enbridge, Inc., Inovio Pharmaceuticals, Microsoft, Parkland Corp., Precigen, Inc., Sirius XM Holdings, Stellantis N.V., Teck Resources Ltd., Toronto Dominion Bank, West Fraser Timber Co. Ltd., and Yamana Gold, Inc.; and research funding from CIHR via Sunnybrooke Research Institute and GSK/PPD Investigator Services. All remaining authors have nothing to disclose., (Copyright © 2022 by the American Society of Nephrology.)