Skin mottling score assesses peripheral tissue hypoperfusion in critically ill patients following cardiac surgery.

BACKGROUND: Skin mottling is a common manifestation of peripheral tissue hypoperfusion, and its severity can be described using the skin mottling score (SMS). This study aims to evaluate the value of the SMS in detecting peripheral tissue hypoperfusion in critically ill patients following cardiac surgery. METHODS: Critically ill patients following cardiac surgery with risk factors for tissue hypoperfusion were enrolled (n = 373). Among these overall patients, we further defined a hypotension population (n = 178) and a shock population (n = 51). Hemodynamic and perfusion parameters were recorded. The primary outcome was peripheral hypoperfusion, defined as significant prolonged capillary refill time (CRT, > 3.0 s). The characteristics and hospital mortality of patients with and without skin mottling were compared. The area under receiver operating characteristic curves (AUROC) were used to assess the accuracy of SMS in detecting peripheral hypoperfusion. Besides, the relationships between SMS and conventional hemodynamic and perfusion parameters were investigated, and the factors most associated with the presence of skin mottling were identified. RESULTS: Of the 373-case overall population, 13 (3.5%) patients exhibited skin mottling, with SMS ranging from 1 to 5 (5, 1, 2, 2, and 3 cases, respectively). Patients with mottling had lower mean arterial pressure, higher vasopressor dose, less urine output (UO), higher CRT, lactate levels and hospital mortality (84.6% vs. 12.2%, p < 0.001). The occurrences of skin mottling were higher in hypotension population and shock population, reaching 5.6% and 15.7%, respectively. The AUROC for SMS to identify peripheral hypoperfusion was 0.64, 0.68, and 0.81 in the overall, hypotension, and shock populations, respectively. The optimal SMS threshold was 1, which corresponded to specificities of 98, 97 and 91 and sensitivities of 29, 38 and 67 in the three populations (overall, hypotension and shock). The correlation of UO, lactate, CRT and vasopressor dose with SMS was significant, among them, UO and CRT were identified as two major factors associated with the presence of skin mottling. CONCLUSION: In critically ill patients following cardiac surgery, SMS is a very specific yet less sensitive parameter for detecting peripheral tissue hypoperfusion.

Extracellular vesicles derived from CD4+ T cells carry DGKK to promote sepsis-induced lung injury by regulating oxidative stress and inflammation.

BACKGROUND: Sepsis is an abnormal immune response after infection, wherein the lung is the most susceptible organ to fail, leading to acute lung injury. To overcome the limitations of current therapeutic strategies and develop more specific treatment, the inflammatory process, in which T cell-derived extracellular vesicles (EVs) play a central role, should be explored deeply. METHODS: Liquid chromatography-tandem mass spectrometry was performed for serum EV protein profiling. The serum diacylglycerol kinase kappa (DGKK) and endotoxin contents of patients with sepsis-induced lung injury were measured. Apoptosis, oxidative stress, and inflammation in A549 cells, bronchoalveolar lavage fluid, and lung tissues of mice were measured by flow cytometry, biochemical analysis, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and western blot. RESULTS: DGKK, the key regulator of the diacylglycerol (DAG)/protein kinase C (PKC) pathway, exhibited elevated expression in serum EVs of patients with sepsis-induced lung injury and showed strong correlation with sepsis severity and disease progression. DGKK was expressed in CD4+ T cells under regulation of the NF-κB pathway and delivered by EVs to target cells, including alveolar epithelial cells. EVs produced by CD4+ T lymphocytes exerted toxic effects on A549 cells to induce apoptotic cell death, oxidative cell damage, and inflammation. In mice with sepsis induced by cecal ligation and puncture, EVs derived from CD4+ T cells also promoted tissue damage, oxidative stress, and inflammation in the lungs. These toxic effects of T cell-derived EVs were attenuated by the inhibition of PKC and NOX4, the downstream effectors of DGKK and DAG. CONCLUSIONS: This approach established the mechanism that T-cell-derived EVs carrying DGKK triggered alveolar epithelial cell apoptosis, oxidative stress, inflammation, and tissue damage in sepsis-induced lung injury through the DAG/PKC/NOX4 pathway. Thus, T-cell-derived EVs and the elevated distribution of DGKK should be further investigated to develop therapeutic strategies for sepsis-induced lung injury.

Postoperative glucocorticoids in patients with acute type A aortic dissection (GLAD): study protocol for a prospective, single-center, randomized controlled trial.

BACKGROUND: Patients receiving surgical treatment of acute type A Aortic Dissection (aTAAD) are common to suffer organ dysfunction in the intensive care unit due to overwhelming inflammation. Previous studies have revealed that glucocorticoids may reduce complications in certain patient groups, but evidence between postoperative glucocorticoids administration and improvement in organ dysfunction after aTAAD surgery are lacking. METHODS: This study will be an investigator-initiated, prospective, single-blind, randomized, single-center study. Subjects with confirmed diagnosis of aTAAD undergoing surgical treatment will be enrolled and 1:1 randomly assigned to receive either glucocorticoids or normal treatment. All patients in the glucocorticoids group will be given methylprednisolone intravenously for 3 days after enrollment. The primary endpoint will be the amplitude of variation of Sequential Organ Failure Assessment score on post-operative day 4 compared to baseline. DISCUSSION: The trial will explore the rationale for postoperative application of glucocorticoids in patients after aTAAD surgery. TRIAL REGISTRATION: This study has been registered on ClinicalTrials.gov (NCT04734418).

Effect of glucocorticoid for patients with type A aortic dissection undergoing surgical repair with deep hypothermic circulatory arrest: A single-center, retrospective study.

BACKGROUND: Postoperative patients with Type A aortic dissection (TAAD) often experience severe inflammatory responses caused by multiple factors perioperatively. However, the effect of postoperative glucocorticoid (GC) use, which is a potent anti-inflammatory agent, on complications or all-cause mortality is unclear. METHODS: Patients with TAAD who underwent surgical repair requiring deep hypothermic circulatory arrest between January 2020 and December 2021 were included in the study. Characteristics of patients treated with and without GCs were compared. The primary outcome was in-hospital mortality, and a composite secondary outcome was defined as in-hospital death or any major complications. Propensity score matching was used to balance baseline differences between groups. Kaplan-Meier curves were used to compare survival probability. RESULTS: A total of 393 postoperative patients with TAAD were included in the study. Forty of them (10.2%) received GC treatment at a median daily methylprednisolone-equivalent dose of 0.6 mg/kg (0.4-0.7) for a median period of 2 (1-3) days. Patients on GCs had more intraoperative blood transfusions, higher postoperative APACHE II (12 vs 9, p = .004) and SOFA (9 vs 6, p < .001) scores, worse perioperative hepatic, renal and cardiac function. The in-hospital mortality in the matched cohort did not differ between groups [GC n = 11/40 (27.5%) versus Non-GC n = 19/80 (23.8%); p = .661]. CONCLUSIONS: The propensity to use GCs correlated with the critical status of the patient. However, low dose and short-term postoperative GC treatment did not reduce in-hospital mortality rates among patients with TAAD. A more appropriate regimen should be further investigated.

Remifentanil versus Dexmedetomidine in Cardiac Surgery Patients with Noninvasive Ventilation Intolerance: Protocol for the REDNIVI Trial.

BACKGROUND: Respiratory failure is one of the most common complications following cardiac surgery. Although noninvasive ventilation (NIV) has been an effective treatment, it has a high rate of intolerance. Both remifentanil and dexmedetomidine are used as sedatives in cardiac surgery (CS) patients with NIV intolerance. However, no randomized controlled trials have compared the effects of these drugs in relieving the intolerance. METHODS: REDNIVI will be a multicenter, prospective, single-blind, randomized controlled trial carried out in six clinical sites in China. Subjects with NIV intolerance will be randomized to receive remifentanil or dexmedetomidine in a ratio of 1:1. Primary outcomes of intolerance remission rate at different timings (15 minutes, 1, 3, 6, 12, 24, 36, 48, 60, 72 hours after initiation of treatment) and 72 h average remission rate will be determined. In addition, secondary outcomes such as mortality, duration of intensive care unit (ICU) stay, duration of mechanical ventilation (MV), the need for endotracheal intubation, hemodynamic changes, and delirium incidence will also be determined. CONCLUSIONS: This trial will provide evidence to determine the effects of remifentanil and dexmedetomidine in patients with NIV intolerance after cardiac surgery. CLINICAL TRIAL REGISTRATION: This study has been registered on ClinicalTrials.gov (NCT04734418).

Early prediction of noninvasive ventilation failure after extubation: development and validation of a machine-learning model.

BACKGROUND: Noninvasive ventilation (NIV) has been widely used in critically ill patients after extubation. However, NIV failure is associated with poor outcomes. This study aimed to determine early predictors of NIV failure and to construct an accurate machine-learning model to identify patients at risks of NIV failure after extubation in intensive care units (ICUs). METHODS: Patients who underwent NIV after extubation in the eICU Collaborative Research Database (eICU-CRD) were included. NIV failure was defined as need for invasive ventilatory support (reintubation or tracheotomy) or death after NIV initiation. A total of 93 clinical and laboratory variables were assessed, and the recursive feature elimination algorithm was used to select key features. Hyperparameter optimization was conducted with an automated machine-learning toolkit called Neural Network Intelligence. A machine-learning model called Categorical Boosting (CatBoost) was developed and compared with nine other models. The model was then prospectively validated among patients enrolled in the Cardiac Surgical ICU of Zhongshan Hospital, Fudan University. RESULTS: Of 929 patients included in the eICU-CRD cohort, 248 (26.7%) had NIV failure. The time from extubation to NIV, age, Glasgow Coma Scale (GCS) score, heart rate, respiratory rate, mean blood pressure (MBP), saturation of pulse oxygen (SpO2), temperature, glucose, pH, pressure of oxygen in blood (PaO2), urine output, input volume, ventilation duration, and mean airway pressure were selected. After hyperparameter optimization, our model showed the greatest accuracy in predicting NIV failure (AUROC: 0.872 [95% CI 0.82-0.92]) among all predictive methods in an internal validation. In the prospective validation cohort, our model was also superior (AUROC: 0.846 [95% CI 0.80-0.89]). The sensitivity and specificity in the prediction group is 89% and 75%, while in the validation group they are 90% and 70%. MV duration and respiratory rate were the most important features. Additionally, we developed a web-based tool to help clinicians use our model. CONCLUSIONS: This study developed and prospectively validated the CatBoost model, which can be used to identify patients who are at risk of NIV failure. Thus, those patients might benefit from early triage and more intensive monitoring. TRIAL REGISTRATION: NCT03704324. Registered 1 September 2018, https://register. CLINICALTRIALS: gov .

The transition and outcomes of perioperative low ejection fraction status in cardiac surgical patients.

Low left ventricular ejection fraction (LVEF) was always considered a high-risk factor for surgery. A growing number of patients with preoperative low LVEF have undergone cardiac surgery in recent years. The transition of postoperative LVEF and its correlation with short-term outcomes is not yet clear. We retrospectively collected the clinical data of cardiac surgery patients with low preoperative LVEF (≤40%). LVEF measurements were collected preoperatively and at least twice postoperatively. The primary endpoint was the composite endpoint of hospital mortality or length of intensive care unit (ICU) stay ≥7 days. Univariate logistic regression was used to evaluate the association of each indicator with the outcomes, including calculation of the area under the receiver operating characteristic (ROC) curve. A two-piecewise linear regression model was applied to examine the threshold effect of the LVEF on the composite endpoint using a smoothing function. From 1 January to 31 December 2018, a total of 123 patients had low LVEF preoperatively, of whom 35 (28.5%) met the composite endpoint. LVEF was 35% [interquartile range (IQR) 30%-42%] at first measurement and increased to 40% (IQR 35%-45%) at final measurement during their hospitalization. There was a linear relationship between composite endpoint and lowest level of postoperative LVEF. The base e logarithm of odds ratio [Ln(OR)] of composite endpoint decreased with increasing LVEF (OR = 0.83, 95% confidence interval 0.76-0.91, p < 0.01). Most patients with low preoperative LVEF will benefit from cardiac surgery. The lowest measurement of postoperative LVEF can be used to evaluate the short-term outcome of patients after cardiac surgery.

Inhaled nitric oxide reduces the intrapulmonary shunt to ameliorate severe hypoxemia after acute type A aortic dissection surgery.

BACKGROUND: To assess the relationship between the intrapulmonary shunt and PaO2/FiO2 in severe hypoxemic patients after acute type A aortic dissection (ATAAD) surgery and to evaluate the effect of inhaled nitric oxide (iNO) on intrapulmonary shunt. METHODS: Postoperative ATAAD patients with PaO2/FiO2 ≤ 150 mmHg were enrolled. Intrapulmonary shunt was calculated from oxygen content of different sites (artery [CaO2], mixed venous [CvO2], and alveolar capillary [CcO2]) using the Fick equation, where intrapulmonary shunt = (CcO2-CaO2)/(CcO2-CvO2). Related variables were measured at baseline (positive end expiratory pressure [PEEP] 5 cm H2O), 30 min after increasing PEEP (PEEP 10 cm H2O), 30 min after 5 ppm iNO therapy (PEEP 10 cm H2O + iNO), and 30 min after decreasing PEEP (PEEP 5 cm H2O + iNO). RESULTS: A total of 20 patients were enrolled between April 2019 and December 2019. Intrapulmonary shunt and PaO2/FiO2 were correlated in severe hypoxemic, postoperative ATAAD patients (adjusted R2 = 0.467, p < 0.001). A mixed model for repeated measures revealed that iNO, rather than increasing PEEP, significantly decreased the intrapulmonary shunt (by 15% at a PEEP of 5 cm H2O and 16% at a PEEP of 10 cm H2O, p < 0.001 each) and increased PaO2/FiO2 (by 63% at a PEEP of 5 cm H2O and 65% at a PEEP of 10 cm H2O, p < 0.001 each). After iNO therapy, the decrement of intrapulmonary shunt and the increment of PaO2/FiO2 were also correlated (adjusted R2 = 0.375, p < 0.001). CONCLUSIONS: This study showed that intrapulmonary shunt and PaO2/FiO2 were correlated in severe hypoxemic, postoperative ATAAD patients. Furthermore, iNO, rather than increasing PEEP, significantly decreased the intrapulmonary shunt to improve severe hypoxemic conditions.

Changes in Stroke Volume Variation Induced by Passive Leg Raising to Predict Fluid Responsiveness in Cardiac Surgical Patients With Protective Ventilation.

OBJECTIVES: Stroke volume variation (SVV) has been used to predict fluid responsiveness. The authors hypothesized the changes in SVV induced by passive leg raising (PLR) might be an indicator of fluid responsiveness in patients with protective ventilation after cardiac surgery. DESIGN: A prospective single-center observational study. SETTING: A single cardiac surgery intensive care unit at a tertiary hospital. PARTICIPANTS: A total of 123 patients undergoing cardiac surgery with hemodynamic instability. Tidal volume was set between 6 and 8 mL/kg of ideal body weight. INTERVENTIONS: PLR maneuver, fluid challenge. MEASUREMENTS AND MAIN RESULTS: SVV was continuously recorded using pulse contour analysis before and immediately after a PLR test and after fluid challenge (500 mL of colloid given over 30 min). Sixty-three (51.22%) patients responded to fluid challenge, in which PLR and fluid challenge significantly increased the SV and decreased the SVV. The decrease in SVV induced by PLR was correlated with the SV changes induced by fluid challenge. A 4% decrease in the SVV induced by PLR-discriminated responders to fluid challenge with an area under the curve of 0.90. The gray zone identified a range of SVV changes induced by PLR (between -3.94% and -2.91%) for which fluid responsiveness could not be predicted reliably. The gray zone included 15.45% of the patients. The SVV at baseline predicted fluid responsiveness with an area under the curve of 0.72. CONCLUSIONS: Changes in the SVV induced by PLR predicted fluid responsiveness in cardiac surgical patients with protective ventilation.

Increased cardiac index attenuates septic acute kidney injury: a prospective observational study.

BACKGROUND: The relationship between cardiac output and septic acute kidney injury (AKI) remains unclear. The purpose of this study was to assess the association between the cardiac index (CI) and the renal outcomes in patients with septic shock. METHODS: A one-year prospective cohort study was performed in the surgical and medical ICU of a teaching hospital in Nanjing, China. Twenty-nine septic shock patients who required early goal-directed fluid resuscitation were consecutively included. Pulse indicator continuous cardiac output (PiCCO) device was used to measure hemodynamic parameters before and after early goal-directed therapy (EGDT). Based on CI changes after EGDT, patients were assign to the CI increased group or the CI constant group, respectively. The incidence of poor renal outcome, which was defined as AKI on admission without recovery in following three days or new onset AKI within 28 days, was recorded. We investigated whether an increased CI was associated with a better renal outcome. RESULTS: After EGDT, there were 16 patients in the CI increased group and 13 patients in the CI constant group. The incidence of poor renal outcome was lower in CI increased group than in the CI constant group (6% vs. 62%; P = 0.003) with a relative risk of 0.10. The logistic regression showed that the CI percent change was associated with renal outcome, with an odd ratio of 0.003 (P = 0.056) after adjustment of possible confounding factors. The CI percent change would predict a good renal outcome (AU ROC 0.739, P = 0.012) with moderate accuracy (sensitivity 75% and specificity 89%) when using a 10% cut-off value from Youden index. The CI percent change was also positively correlated with creatinine clearance (CCr) after EGDT (ρ = 0.548; P = 0.002). CONCLUSIONS: The increased CI after EGDT was a protective factor for kidney in patients with septic shock. A CI increased above 10% could be potentially used to predict development and reversibility of AKI in septic shock patients. TRIAL REGISTRATION: Clinicaltrials.gov:NCT01862588 (May 13, 2013).

Data science in the intensive care unit.

In this editorial, we comment on the current development and deployment of data science in intensive care units (ICUs). Data in ICUs can be classified into qualitative and quantitative data with different technologies needed to translate and interpret them. Data science, in the form of artificial intelligence (AI), should find the right interaction between physicians, data and algorithm. For individual patients and physicians, sepsis and mechanical ventilation have been two important aspects where AI has been extensively studied. However, major risks of bias, lack of generalizability and poor clinical values remain. AI deployment in the ICUs should be emphasized more to facilitate AI development. For ICU management, AI has a huge potential in transforming resource allocation. The coronavirus disease 2019 pandemic has given opportunities to establish such systems which should be investigated further. Ethical concerns must be addressed when designing such AI.

Weaning from venous-arterial extracorporeal membrane oxygenation: The hemodynamic and clinical aspects of flow challenge test.

The cardiac function reserve is crucial for the successful weaning of V-A ECMO. During the V-A ECMO weaning phase, the gradual reduction in pump flow converts the blood flow originally driven by the pump to native cardiac output and also transforms afterload (caused by retrograde flow) into ventricular preload, thus introducing a "flow challenge" to the native heart. In this perspective, we propose to use this flow challenge as a test to simulate the preload-to-afterload conversion to assess cardiac functional reserve quantitatively. With this short article we offer the hemodynamic and clinical aspects regarding the flow challenge test.

Recombinant human brain natriuretic peptide ameliorates venous return function in congestive heart failure.

AIMS: Recombinant human brain natriuretic peptide (rh-BNP) is commonly used as a decongestive therapy. This study aimed to investigate the instant effects of rh-BNP on cardiac output and venous return function in post-cardiotomy patients with congestive heart failure (CHF). METHODS AND RESULTS: Twenty-four post-cardiotomy heart failure patients were enrolled and received a standard loading dose of rh-BNP. Haemodynamic monitoring was performed via a pulmonary artery catheter before and after the administration of rh-BNP. The cardiac output and venous return functions were estimated by depicting Frank-Starling and Guyton curves. After rh-BNP infusion, variables reflecting cardiac congestion and venous return function, such as pulmonary artery wedge pressure, mean systemic filling pressure (Pmsf) and venous return resistance index (VRRI), reduced from 15 ± 3 to 13 ± 3 mmHg, from 32 ± 7 to 28 ± 7 mmHg and from 6.7 ± 2.6 to 5.7 ± 1.8 mmHg min m2 /L, respectively. Meanwhile, cardiac index, stroke volume index, and the cardiac output function curve remained unchanged per se. The decline in Pmsf [-13% (-22% to -8%)] and VRRI [-12% (-25% to -5%)] was much greater than that in the systemic vascular resistance index [-7% (-14% to 0%)]. In the subgroup analysis of reduced ejection fraction (<40%) patients, the aforementioned changes were more significant. CONCLUSIONS: rh-BNP might ameliorate venous return rather than cardiac output function in post-cardiotomy CHF patients.

Exosome-Derived From Sepsis Patients' Blood Promoted Pyroptosis of Cardiomyocytes by Regulating miR-885-5p/HMBOX1.

Background: Septic myocardial depression has been associated with increased morbidity and mortality. miR-885-5p has been shown to regulate cell growth, senescence, and/or apoptosis. Published studies demonstrated that Homeobox-containing protein 1 (HMBOX1) inhibits inflammatory response, regulates cell autophagy, and apoptosis. However, the role of miR-885-5p/HMBOX1 in sepsis and septic myocardial depression and the underlying mechanism is not fully understood. Materials and Methods: Exosomes (exos) derived from sepsis patients (sepsis-exos) were isolated using ultracentrifugation. Rats were subjected to cecal ligation and puncture surgery and treated with sepsis-exos. HMBOX1 was knocked down or overexpressed in AC16 cells using lentiviral plasmids carrying short interfering RNAs targeting human HMBOX1 or carrying HMBOX1 cDNA. Cell pyroptosis was measured by flow cytometry. The secretion of IL-1ß and IL-18 was examined by ELISA kits. Quantitative polymerase chain reaction (PCR) or western blot was used for gene expression. Results: Sepsis-exos increased the level of miR-885-5p, decreased HMBOX1, elevated IL-1ß and IL-18, and promoted pyroptosis in AC16 cells. Septic rats treated with sepsis-exos increased the serum inflammatory cytokines is associated with increased pyroptosis-related proteins of hearts. MiR-885-5p bound to the three prime untranslated regions of HMBOX1 to negatively regulate its expression. Overexpressing HMBOX1 reversed miR-885-5p-induced elevation of inflammatory cytokines and upregulation of NLRP3, caspase-1, and GSDMD-N in AC16 cells. The mechanistic study indicated that the effect of HMBOX1 was NF-κB dependent. Conclusion: Sepsis-exos promoted the pyroptosis of AC16 cells through miR-885-5p via HMBOX1. The results show the significance of the miR-885-5p/HMBOX1 axis in myocardial cell pyroptosis and provide new directions for the treatment of septic myocardial depression.

INFRARED THERMOGRAPHY-BASED BODY-SURFACE THERMAL INHOMOGENEITY MONITORING TO ASSESS THE SEVERITY OF HYPOPERFUSION IN CRITICALLY ILL PATIENTS.

ABSTRACT: Background: Uneven body-surface thermal distribution is a manifestation of hypoperfusion and can be quantified by infrared thermography. Our aim was to investigate whether body-surface thermal inhomogeneity could accurately evaluate the severity of patients at risk of hypoperfusion. Methods: This was a prospective cohort study in which infrared thermography images were taken from unilateral legs of critically ill patients at high risk of hypoperfusion in a cardiac surgical intensive care unit. For each patient, five body-surface thermal inhomogeneity parameters, including standard deviation (SD), kurtosis, skewness, entropy, and low-temperature area rate (LTAR), were calculated. Demographic, clinical, and thermal characteristics of deceased and living patients were compared. The risk of mortality and capillary refill time (CRT) were chosen as the primary outcome and benchmarking parameter for hypoperfusion, respectively. The area under the receiver operating characteristic curve (AUROC) was used to evaluate predictive accuracy. Results: Three hundred seventy-three patients were included, and 55 (14.7%) died during hospital stay. Of inhomogeneity parameters, SD (0.738) and LTAR (0.768) had similar AUROC to CRT (0.757) for assessing mortality risk. Besides, there was a tendency for LTAR (1%-3%-7%) and SD (0.81°C-0.88°C-0.94°C) to increase in normotensive, hypotensive, and shock patients. These thermal parameters are associated with CRT, lactate, and blood pressure. The AUROC of a combined prediction incorporating three thermal inhomogeneity parameters (SD, kurtosis, and entropy) was considerably higher at 0.866. Conclusions: Body-surface thermal inhomogeneity provided a noninvasive and accurate assessment of the severity of critically ill patients at high risk of hypoperfusion.

Early postoperative organ dysfunction is highly associated with the mortality risk of patients with type A aortic dissection.

OBJECTIVES: This study assessed the impact of early postoperative organ dysfunction (EPOD) on in-hospital mortality of patients with type A aortic dissection (TAAD) after surgery. METHODS: Patients with TAAD who underwent surgical repair requiring deep hypothermic circulatory arrest from January 2020 to December 2021 were included. The Sequential Organ Failure Assessment (SOFA) score was calculated for 3 days postoperatively to stratify the severity of organ dysfunction. Patients with the SOFA of 0-4, 5-8 or >8 were defined as mild, moderate or severe EPOD. The primary outcome was in-hospital mortality, and a composite secondary outcome was defined as in-hospital death or any major complications. Kaplan-Meier curves were used to compare survival probability. The area under the receiver operating characteristic curve and calibration plots were used to evaluate the predictive power and overall performance of SOFA. RESULTS: Of the 368 patients, 5 patients (3%) with moderate EPOD and 33 patients (23%) with severe EPOD died. No patient died with mild EPOD. The areas under the receiver operating characteristic curve of SOFA for predicting mortality and the composite outcome were 0.85 (0.81-0.88) and 0.81 (0.77-0.85) on postoperative day 1. Each point of postoperative day 1 SOFA score corresponded to an odds ratio of 1.65 (1.42-1.92) for mortality. Of the 6 components of the SOFA system, only coagulation (2.34 [1.32-4.13]), cardiovascular (1.47 [1.04-2.08]), central nervous system (1.96 [1.36-2.82]) and renal (1.67 [1.04-2.70]) functions were associated with the higher risk of mortality. CONCLUSIONS: EPOD stratified by the SOFA score was associated with a higher risk of death and predicted the clinical outcomes of patients with TAAD with good accuracy.

Serum creatinine as a predictor of mortality in patients readmitted to the intensive care unit after cardiac surgery: a retrospective cohort study in China.

BACKGROUND: Patients readmitted to the intensive care unit (ICU) after cardiac surgery have a high mortality rate. The relationship between renal function and in-hospital mortality in readmitted patients has not been well demonstrated. METHODS: We retrospectively evaluated cardiac surgery patients who were readmitted to the ICU at least once. Data on serum creatinine levels before surgery and on the day of ICU readmission were collected. The estimated glomerular filtration rate (eGFR) was calculated according to the creatinine-based Chronic Kidney Disease-Epidemiology Collaboration equation. We used logistic regression models and restricted cubic spline curves with four knots (5%, 35%, 65%, 95%) to investigate the relationship between renal function indicators and mortality. RESULTS: Of the 184 patients evaluated, 30 patients died during hospitalization, yielding a mortality rate of 16.30%. Cardiac dysfunction (n=84, 45.65%) and respiration disorder (n=51, 27.72%) were the most common reasons for ICU readmission. Creatinine [odds ratio (OR): 1.14, 95% confidence interval (CI): 1.07-1.25] and eGFR (OR: 0.95, 95% CI: 0.93-0.98) were independently associated with in-hospital mortality after adjusting for various confounders. Both creatinine level and eGFR had a linear association with in-hospital mortality (P for non-linearity ˃0.05). CONCLUSION: Renal function is significantly associated with the in-hospital mortality of patients readmitted to the ICU after cardiac surgery, as evidenced by the independent correlation of both creatinine and eGFR with in-hospital mortality.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: A Potential Therapeutic Strategy for Acute Kidney Injury.

Acute kidney injury (AKI) is a common and potential life-threatening disease in patients admitted to hospital, affecting 10%-15% of all hospitalizations and around 50% of patients in the intensive care unit. Severe, recurrent, and uncontrolled AKI may progress to chronic kidney disease or end-stage renal disease. AKI thus requires more efficient, specific therapies, rather than just supportive therapy. Mesenchymal stem cells (MSCs) are considered to be promising cells for cellular therapy because of their ease of harvesting, low immunogenicity, and ability to expand in vitro. Recent research indicated that the main therapeutic effects of MSCs were mediated by MSC-derived extracellular vesicles (MSC-EVs). Furthermore, compared with MSCs, MSC-EVs have lower immunogenicity, easier storage, no tumorigenesis, and the potential to be artificially modified. We reviewed the therapeutic mechanism of MSCs and MSC-EVs in AKI, and considered recent research on how to improve the efficacy of MSC-EVs in AKI. We also summarized and analyzed the potential and limitations of EVs for the treatment of AKI to provide ideas for future clinical trials and the clinical application of MSC-EVs in AKI.

Levosimendan to Facilitate Weaning From Cardiorespiratory Support in Critically Ill Patients: A Meta-Analysis.

Background: Cardiopulmonary support, as extracorporeal membrane oxygenation (ECMO) or mechanical ventilation (MV), is crucial for ICU patients. However, some of these patients are difficult to wean. Therefore, we aimed to assess the efficacy and safety of levosimendan in facilitating weaning from cardiorespiratory support in this patient population. Methods: We searched for potentially relevant articles in PubMed, Embase, China National Knowledge Infrastructure, Wanfang, and the Cochrane database from inception up to Feb 30, 2021. Studies focusing on weaning data in MV/ECMO adult patients who received levosimendan compared to controls were included. We used the Cochrane risk of bias tool or the Newcastle-Ottawa Quality Assessment Scale to evaluate the study quality. The primary outcome was the weaning rate from MV/ECMO. Secondary outcomes were mortality, duration of MV, and ICU stay. Subgroup analysis, sensitivity analysis, and publication bias were also conducted. Results: Eighteen studies with 2,274 patients were included. The quality of the included studies was low to moderate. Overall, levosimendan effectively improved weaning rates from MV/ECMO [odds ratio (OR) = 2.32; 95%CI, 1.60-3.36; P < 0.00001, I 2 = 68%]. Subgroup analyses confirmed the higher successful weaning rates in ventilated patients with low left ventricular ejection fractions (OR = 4.06; 95%CI, 2.16-7.62), patients with ECMO after cardiac surgery (OR = 2.04; 95%CI, 1.25-3.34), and patients with ECMO and cardiogenic shock (OR = 1.98; 95%CI, 1.34-2.91). However, levosimendan showed no beneficial effect on patients with MV weaning difficulty (OR = 2.28; 95%CI, 0.72-7.25). Additionally, no differences were found concerning the secondary outcomes between the groups. Conclusions: Levosimendan therapy significantly increased successful weaning rates in patients with cardiopulmonary support, especially patients with combined cardiac insufficiency. Large-scale, well-designed RCTs will be needed to define the subgroup of patients most likely to benefit from this strategy.

Propensity score matching with R: conventional methods and new features.

It is increasingly important to accurately and comprehensively estimate the effects of particular clinical treatments. Although randomization is the current gold standard, randomized controlled trials (RCTs) are often limited in practice due to ethical and cost issues. Observational studies have also attracted a great deal of attention as, quite often, large historical datasets are available for these kinds of studies. However, observational studies also have their drawbacks, mainly including the systematic differences in baseline covariates, which relate to outcomes between treatment and control groups that can potentially bias results. Propensity score methods, which are a series of balancing methods in these studies, have become increasingly popular by virtue of the two major advantages of dimension reduction and design separation. Within this approach, propensity score matching (PSM) has been empirically proven, with outstanding performances across observational datasets. While PSM tutorials are available in the literature, there is still room for improvement. Some PSM tutorials provide step-by-step guidance, but only one or two packages have been covered, thereby limiting their scope and practicality. Several articles and books have expounded upon propensity scores in detail, exploring statistical principles and theories; however, the lack of explanations on function usage in programming language has made it difficult for researchers to understand and follow these materials. To this end, this tutorial was developed with a six-step PSM framework, in which we summarize the recent updates and provide step-by-step guidance to the R programming language. This tutorial offers researchers with a broad survey of PSM, ranging from data preprocessing to estimations of propensity scores, and from matching to analyses. We also explain generalized propensity scoring for multiple or continuous treatments, as well as time-dependent PSM. Lastly, we discuss the advantages and disadvantages of propensity score methods.