Preoperative endothelial dysfunction for the prediction of acute kidney injury after cardiac surgery using cardiopulmonary bypass: a pilot study based on a second analysis of the MONS study.

BACKGROUND: Up to 42% of patients develop acute kidney injury (AKI) after cardiac surgery. The aim of this study was to describe the relationship between preoperative microcirculatory function and postoperative AKI after cardiac surgery using cardiopulmonary bypass (CPB). METHODS: The prospective observational cohort MONS enrolled 60 patients scheduled for valvular (n = 30, 50%) or coronary (n = 30, 50%) surgery using CPB. Preoperative microcirculation was assessed during preoperative consultation from January 2019 to April 2019 at the University Hospital of Angers, France, using endothelium-dependent and endothelium-independent reactivity tests on the forearm (iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP), respectively). Skin blood flow was measured by laser speckle contrast imaging. The primary endpoint was the occurrence of AKI according to the KDIGO classification during the hospital stay. RESULTS: Forty-three (71.7%) patients developed AKI during the in-hospital follow-up, and 15 (25%) were classified as KDIGO stage 1, 20 (33%) KDIGO stage 2, and 8 (13%) KDIGO stage 3. Regarding preoperative microcirculation, a higher peak amplitude of vasodilation in response to iontophoresis of ACh was found in patients with postoperative occurrence of AKI (35 [20-49] vs 23 [9-44] LSPU, p = 0.04). Iontophoresis of SNP was not significantly different according to AKI occurrence (34 [22-49] vs 36 [20-50] LSPU, p = 0.95). In a multivariable model, the preoperative peak amplitude at iontophoresis of ACh was independently associated with postoperative AKI (OR 1.045 [1.001-1.092], p = 0.045). CONCLUSIONS: The preoperative peak amplitude of endothelium-dependent vasodilation is independently associated with the postoperative occurrence of AKI. TRIAL REGISTRATION: Clinical-Trials.gov, NCT03631797. Registered 15 August 2018, https://clinicaltrials.gov/ct2/show/NCT03631797.

Prognostic value of capillary refill time in adult patients: a systematic review with meta-analysis.

PURPOSE: Acute circulatory failure leads to tissue hypoperfusion. Capillary refill time (CRT) has been widely studied, but its predictive value remains debated. We conducted a meta-analysis to assess the ability of CRT to predict death or adverse events in a context at risk or confirmed acute circulatory failure in adults. METHOD: MEDLINE, EMBASE, and Google scholar databases were screened for relevant studies. The pooled area under the ROC curve (AUC ROC), sensitivity, specificity, threshold, and diagnostic odds ratio using a random-effects model were determined. The primary analysis was the ability of abnormal CRT to predict death in patients with acute circulatory failure. Secondary analysis included the ability of CRT to predict death or adverse events in patients at risk or with confirmed acute circulatory failure, the comparison with lactate, and the identification of explanatory factors associated with better accuracy. RESULTS: A total of 60,656 patients in 23 studies were included. Concerning the primary analysis, the pooled AUC ROC of 13 studies was 0.66 (95%CI [0.59; 0.76]), and pooled sensitivity was 54% (95%CI [43; 64]). The pooled specificity was 72% (95%CI [55; 84]). The pooled diagnostic odds ratio was 3.4 (95%CI [1.4; 8.3]). Concerning the secondary analysis, the pooled AUC ROC of 23 studies was 0.69 (95%CI [0.65; 0.74]). The prognostic value of CRT compared to lactate was not significantly different. High-quality CRT was associated with a greater accuracy. CONCLUSION: CRT poorly predicted death and adverse events in patients at risk or established acute circulatory failure. Its accuracy is greater when high-quality CRT measurement is performed.

Lower Limb Ischemia in Surgical Femoral Veno-Arterial Extracorporeal Membrane Oxygenation.

OBJECTIVES: To analyze the incidence, clinical impact on survival, and risk factors of lower limb ischemia (LLI) of surgical peripheral femoral venoarterial extracorporeal membrane oxygenation (VA ECMO) in the current era. DESIGN: A retrospective analysis of the authors' institutional database of VA ECMO was performed. Patients were divided into 2 groups according to the occurrence of LLI. The primary endpoint was survival to hospital discharge. Risk factors of LLI were searched with multivariate analyses. SETTING: University hospital. PARTICIPANTS: Adult patients receiving peripheral VA ECMO for refractory cardiogenic shock and cardiac arrest. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: From January 2018 to December 2021, 188 patients (mean age: 52.0 ± 14.1 years; 63.8% male, 36.2% female) received peripheral VA ECMO. Male sex was more prevalent in the group without LLI (65.9% v 33.3%; p = 0.031). Twelve (6.4%) patients developed LLI during VA ECMO support (n = 6) or after VA ECMO removal (n = 6). Survival to hospital discharge was not statistically different between patients with and without LLI (50.0% v 48.3%; p = 0.571). Female sex patients were at increased risk for LLI (odds ratio 4.38, 95% CI 1.21-15.81; p = 0.024). CONCLUSIONS: Peripheral femoral VA ECMO through a surgical approach is associated with a low LLI rate, which does not increase the risk of in-hospital mortality. The female sex is an independent risk factor for LLI.

Prolonged cardiovascular pharmacological support and fluid management after cardiac surgery.

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.

A Multimodal Cardioprotection Strategy During Cardiac Surgery: The ProCCard Study.

OBJECTIVE: The ProCCard study tested whether combining several cardioprotective interventions would reduce the myocardial and other biological and clinical damage in patients undergoing cardiac surgery. DESIGN: Prospective, randomized, controlled trial. SETTING: Multicenter tertiary care hospitals. PARTICIPANTS: 210 patients scheduled to undergo aortic valve surgery. INTERVENTIONS: A control group (standard of care) was compared to a treated group combining five perioperative cardioprotective techniques: anesthesia with sevoflurane, remote ischemic preconditioning, close intraoperative blood glucose control, moderate respiratory acidosis (pH 7.30) just before aortic unclamping (concept of the "pH paradox"), and gentle reperfusion just after aortic unclamping. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the postoperative 72-h area under the curve (AUC) for high-sensitivity cardiac troponin I (hsTnI). Secondary endpoints were biological markers and clinical events occurring during the 30 postoperative days and the prespecified subgroup analyses. The linear relationship between the 72-h AUC for hsTnI and aortic clamping time, significant in both groups (p < 0.0001), was not modified by the treatment (p = 0.57). The rate of adverse events at 30 days was identical. A non-significant reduction of the 72-h AUC for hsTnI (-24%, p = 0.15) was observed when sevoflurane was administered during cardiopulmonary bypass (46% of patients in the treated group). The incidence of postoperative renal failure was not reduced (p = 0.104). CONCLUSION: This multimodal cardioprotection has not demonstrated any biological or clinical benefit during cardiac surgery. The cardio- and reno-protective effects of sevoflurane and remote ischemic preconditioning therefore remain to be demonstrated in this context.

Reliability and reproducibility of the DICART device to assess capillary refill time: a bench and in-silico study.

Capillary refill time (CRT) is an important indicator of peripheral perfusion with a strong prognostic value, but it is sensitive to environmental factors and numerous measurement methods are reported in the litterature. DiCARTECH has developed a device that assesses CRT. We sought to investigate the robustness of the device and the reproducibility of the algorithm in a bench and in-silico study. We used the video acquired from a previous clinical study on healthy volunteers. For the bench study, the measurement process was performed by a robotic system piloted by a computer that analyzed 250 times nine previously acquired videos. For the in-silico study, we used 222 videos to test the algorithm's robustness. We created 30 videos from each video with a large blind spot and used the "color jitter" function to create a hundred videos from each video. In the bench study, the coefficient of variation was 11% (95%CI: 9-13). The correlation with human-measured CRT was good (R2 = 0.91, P < 0.001). In the in-silico study, for the blind spotted video, the coefficient of variation was 13% (95%CI: 10-17). For the color-jitter modified video the coefficient of variation was 62% (95%CI: 55-70). We confirmed the ability of the DiCART™ II device to perform multiple measurements without mechanical or electronic dysfunction. The precision and reproducibility of the algorithm are compatible with the assessment of clinical small changes in CRT.

Hemodynamic Effects of Awake Prone Positioning With COVID-19 Acute Respiratory Failure.

INTRODUCTION: Awake prone positioning (PP) reduces need for intubation for patients with COVID-19 with acute respiratory failure. We investigated the hemodynamic effects of awake PP in non-ventilated subjects with COVID-19 acute respiratory failure. METHODS: We conducted a single-center prospective cohort study. Adult hypoxemic subjects with COVID-19 not requiring invasive mechanical ventilation receiving at least one PP session were included. Hemodynamic assessment was done with transthoracic echocardiography before, during, and after a PP session. RESULTS: Twenty-six subjects were included. We observed a significant and reversible increase in cardiac index (CI) during PP compared to supine position (SP): 3.0 ± 0.8 L/min/m2 in PP, 2.5 ± 0.6 L/min/m2 before PP (SP1), and 2.6 ± 0.5 L/min/m2 after PP (SP2, P < .001). A significant improvement in right ventricular (RV) systolic function was also evidenced during PP: The RV fractional area change was 36 ± 10% in SP1, 46 ± 10% during PP, and 35 ± 8% in SP2 (P < .001). There was no significant difference in PaO2 /FIO2 and breathing frequency. CONCLUSION: CI and RV systolic function are improved by awake PP in non-ventilated subjects with COVID-19 with acute respiratory failure.

Central Versus Peripheral Arterial Pressure Monitoring in Patients Undergoing Cardiac Surgery: A Prospective Observational Study.

OBJECTIVE: The aortic-to-radial arterial pressure gradient is described during and after cardiopulmonary bypass (CPB), and can lead to underestimating arterial blood pressure. The authors hypothesized that central arterial pressure monitoring would be associated with lower norepinephrine requirements than radial arterial pressure monitoring during cardiac surgery. DESIGN: An observational prospective cohort with propensity score analysis. SETTING: At a tertiary academic hospital's operating room and intensive care unit (ICU). PARTICIPANTS: A total of 286 consecutive adult patients undergoing cardiac surgery with CPB (central group: 109; radial group: 177) were enrolled and analyzed. INTERVENTIONS: To explore the hemodynamic effect of the measurement site, the authors divided the cohort into 2 groups according to a femoral/axillary (central group) or radial (radial group) site of arterial pressure monitoring. MEASUREMENT AND MAIN RESULTS: The primary outcome was the intraoperative amount of norepinephrine administered. Secondary outcomes included norepinephrine-free hours and ICU-free hours at postoperative day 2 (POD2). A logistic model with propensity score analysis was built to predict central arterial pressure monitoring use. The authors compared demographic, hemodynamic, and outcomes data before and after adjustment. Central group patients had a higher European System for Cardiac Operative Risk Evaluation. (EuroSCORE) compared to the radial group-7.9 ± 14.0 versus 3.8 ± 7.0, p < 0.001. After adjustment, both groups had similar patient EuroSCORE and arterial blood pressure levels. Intraoperative norepinephrine dose regimens were 0.10 ± 0.10 µg/kg/min in the central group and 0.11 ± 0.11 µg/kg/min in the radial group (p = 0.519). Norepinephrine-free hours at POD2 were 38 ± 17 hours versus 33 ± 19 hours in central and radial groups, respectively (p = 0.034). The ICU-free hours at POD2 were greater in the central group: 18 ± 13 hours versus 13 ± 13 hours, p = 0.008. Adverse events were less frequent in the central group than in the radial group-67% versus 50%, p = 0.007. CONCLUSIONS: No differences in the norepinephrine dose regimen were found according to the arterial measurement site during cardiac surgery. However, norepinephrine use and length of stay in the ICU were shorter, and adverse events were decreased when central arterial pressure monitoring was used.

Advantages and limitations of noninvasive devices for cardiac output monitoring: a literature review.

PURPOSE OF REVIEW: Individualized hemodynamic optimization often requires cardiac output monitoring, mostly for goal-directed therapy in the operating room and fluid responsiveness assessment in the intensive care unit. Different technologies for noninvasive cardiac output determination have become available over the recent years. It is therefore crucial for care providers to be made aware of the advantages and limitations of those different devices for an appropriate use at the bedside. RECENT FINDINGS: Nowadays, different noninvasive technologies exist, each with their advantages and limitations, but none are considered interchangeable with bolus thermodilution. Different clinical studies however, emphasize that the trending ability of such devices allows to guide decisions from care providers, and that their use may be associated with improved prognosis, especially in the operating room. Recent studies have also reported their potential use for hemodynamic optimization in specific populations. SUMMARY: Noninvasive cardiac output monitoring may have a clinical impact on patient outcomes. Further studies are required to evaluate their clinical relevance, notably in the intensive care unit. Noninvasive monitoring opens up the possibility for hemodynamic optimization in specific or low-risk populations, the benefit of which remains to be assessed.

Elaboration of a French version of the Duke Activity Status Index questionnaire and performance to predict functional capacity.

BACKGROUND: Guidelines recommend detecting poor functional capacity (VO2max < 14 ml.kg-1.min-1) to assess preoperative cardiac risk. This screening is performed via a cardiopulmonary exercise test (CPET), the self-reported inability to climb two flights of stairs, or the use of the Duke Activity Status Index (DASI) questionnaire, which has shown a significant correlation with VO2max and postoperative outcomes. The objectives of the present study were: 1) to create a French version of the DASI questionnaire (FDASI); 2) to assess its diagnostic performance in predicting functional capacity. METHODS: Consecutive adult patients undergoing CPET for medical or preoperative evaluation were prospectively included between May 2020 and March 2021. All patients were asked to complete FDASI as a self-questionnaire and report their inability to climb two flights of stairs. RESULTS: 122 patients were included. Test-retest reliability was 0.88 and 23 (19%) patients experienced a VO2max < 14 ml.kg-1.min-1. There was a significant positive relationship between FDASI and VO2max: r2 = 0.32; p < 0.001. ROCAUC was 0.81 [95%CI: 0.73-0.89]. The best FDASI score threshold was 36 points, leading to sensitivity and specificity values of 87% [74-100] and 68% [56-79], respectively. Besides, sensitivity and specificity were 35% [17-56] and 92% [86-97] for the self-reported inability to climb two flights of stairs. CONCLUSION: A FDASI score of 36 represents a reliable threshold the clinicians could routinely use to identify patients with a VO2max < 14 ml.kg-1.min-1. FDASI could advantageously replace the self-reported inability to climb two flights of stairs.

Bioelectrical impedance analysis during deresuscitation: correlation and agreement with cumulative fluid balance in ICU patients.

Bioelectrical impedance analysis (BIA) is a promising tool to evaluate the body composition of critically-ill patients. The present study aimed to assess its value as a fluid management monitoring tool during standardized deresuscitation strategy. A historical cohort of critically-ill adult patients with fluid overload and continuous renal replacement therapy was used to explore both relationship and agreement between changes in cumulative fluid balance and BIA-derived hydration variables within the 5 days following initiation of deresuscitation strategy using net ultrafiltration. Correlations were described using Spearman's rank correlation coefficient, and agreement using Bland-Altman analysis for repeated measurements. Sixty-one couples of fluid shift measurements from 30 patients were analyzed. The deresuscitation strategy induced a negative mean (± SD) cumulative fluid balance (- 4.2 ± 3.8 L) and a significant decrease in extra- and intracellular water (P < 0.001). Decreases in extra- and intracellular water were independent of weight variations inputted in the BIA device. Total body water (rho = 0.63), extracellular water (rho = 0.68), and intracellular water (rho = 0.67) were significantly correlated with cumulative fluid balance (all P values < 0.001). The limits of agreement did not allow interchangeability for a delta of 2L between cumulative fluid balance and BIA-derived hydration variables (P > 0.05). BIA hydration-derived variables are significantly correlated with cumulative fluid balance but the large limits of agreements exclude interchangeability of the measures.

Refilling and preload dependence failed to predict cardiac index decrease during fluid removal with continuous renal replacement therapy.

BACKGROUND: Fluid removal can reduce the burden of fluid overload after initial resuscitation. According to the Frank-Starling model, iatrogenic hypovolemia should induce a decrease in cardiac index. We hypothesized that inadequate refilling detected by haemoconcentration during fluid removal or an increase in cardiac index (CI) during passive leg raising (PLR) could predict CI decrease during mechanical fluid removal with continuous renal replacement therapy (CRRT). METHODS: We conducted a single-centre prospective diagnostic accuracy study. The primary objective was to investigate the diagnostic performance of plasma protein concentration variations in detecting a CI decrease ≥ 12% during mechanical fluid removal. Secondary objective was to assess other predictive factors of CI change. The attending physician prescribed a fluid removal challenge consisting of a mechanical fluid removal challenge of 500 mL for one hour. Plasma protein concentration, haemoglobin level, PLR and transpulmonary thermodilution were done before and after the fluid removal challenge. RESULTS: We included 69 adult patients between December 2016 and April 2020. Sixteen patients had a significant CI decrease (23% [95% CI 14-35]). Haemoconcentration and PLR before fluid removal challenge or CI trending failed to predict CI decrease. CONCLUSION: Haemoconcentration variables, preload dependence status and CI trending failed to predict CI decrease during fluid removal challenge.

Perfusion-based deresuscitation during continuous renal replacement therapy: A before-after pilot study (The early dry Cohort).

BACKGROUND: Active fluid removal has been suggested to improve prognosis following the resolution of acute circulatory failure. We have implemented a routine care protocol to guide fluid removal during continuous renal replacement therapy (CRRT). We designed a before-after pilot study to evaluate the impact of this deresuscitation strategy on the fluid balance. METHODS: Consecutive ICU patients suffering from fluid overload and undergoing CRRT for acute kidney injury underwent a perfusion-based deresuscitation protocol combining a restrictive intake, net ultrafiltration (UFnet) of 2 mL/kg/h, and monitoring of perfusion (early dry group, N = 42) and were compared to a historical group managed according to usual practices (control group, N = 45). The primary outcome was the cumulative fluid balance at day 5 or at discharge. RESULTS: Adjusted cumulative fluid balance was significantly lower in the early dry group (median [IQR]: -7784 [-11,833 to -2933] mL) compared to the control group (-3492 [-9935 to -1736] mL; p = 0.04). The difference was mainly driven by a greater daily UFnet (31 [22-46] mL/kg/day vs. 24 [15-32] mL/kg/day; p = 0.01). There was no significant difference between both groups regarding hemodynamic tolerance. CONCLUSION: Our perfusion-based deresuscitation protocol achieved a greater negative cumulative fluid balance compared to standard practices and was hemodynamically well tolerated.