Aitaliyev, Serik

Background: The bleeding in cardiac surgery remains a significant clinical problem. There is no "gold standard" method to quantify blood loss. Traditional measurement of drainage volume often underestimates or overestimates, as it does not consider the type of fluid. We hypothesized that blood loss could be more accurately calculated using the Hb/kg index in terms of haemoglobin (Hb) mass loss per kilogram of the patient's body mass. This study aimed to Objective To develop a novel approach for calculating actual blood loss using the Hb/kg index. Methods: This single-center prospective study included 195 patients who underwent cardiac surgery between October 2023 and November 2024. The Hb/kg index was calculated based on intraoperative Hb loss, Hb loss via chest tubes, packed red blood cell transfusions and patient weight. Eighty-six additional clinical predictors were analyzed using conventional statistics and machine learning algorithms. Predictors with statistically significant Spearman correlations were included for further analysis. Results: Lasso regression achieved the best overall performance in predicting Hb/kg index. It yielded the lowest mean squared error (0.08 ± 0.04), mean absolute percentage error (0.18 ± 0.10), with the highest correlation (0.92 ± 0.06) and R² score (0.82 ± 0.13). BMI showed a significant negative relationship (-0.018, p < 0.001). Postoperative Hb and haematocrit values had negative correlation (-0.69, p < 0.001 and -0.07, p < 0.015), while initial Hb was positively correlated (0.85, p < 0.001). Conclusions: This method provides a more reliable and clinically relevant tool to calculate actual blood loss and allows for a more precise assessment and treatment.

Background There is no universally accepted definition of perioperative blood loss in cardiac surgery. Existing methods are based on chest tube output and are not normalised for patient weight. Objective To validate machine learning-derived blood loss severity clusters based on a haemoglobin mass loss per kilogram (Hb/kg index). Methods This single-center prospective study included 195 patients undergoing cardiac surgery between October 2023 and November 2024. Three clusters derived using K-Medoids were mapped to the Hb/kg index to define cut-offs. Cluster discrimination was assessed by receiver operating characteristics (ROC) analysis (area under the curve (AUC)). Group comparisons were performed using analysis of covariance adjusted for age and gender. Associations between the Hb/kg index and clinical outcomes, including transfusion requirements and complications were analysed using Chi-square tests and adjusted two-way Analysis of Covariance (ANCOVA). Results Clustering identified three groups (Mild, Moderate, Severe) defined by optimal Hb/kg thresholds of 1.72 and 2.10. The Severe cluster demonstrated strong discriminative performance (AUC = 0.790, 95% confidence interval 0.721-0.859). Chest tube output did not differ significantly between clusters (= 0.097), while haemoglobin mass loss through chest tubes demonstrated a significant effect (p = 0.011). Conclusions The Hb/kg Index is a validated, data-driven, objective metric for perioperative blood loss, offering greater precision than traditional chest tube drainage volume. It effectively stratifies bleeding severity and identifies high-risk patients with lower BMI.

Postoperative bleeding following cardiopulmonary bypass (CPB) remains a significant challenge.Although viscoelastic testing is increasingly used, the relative contributions of fibrinogen, platelet count and clot firm-ness to blood loss remain debated. We evaluated the diagnostic accuracy of thromboelastometry (ROTEM) comparedwith platelet aggregometry (PA) and standard tests, using the Hb/kg index to quantify blood loss.

Background: Giant descending thoracic aortic aneurysm (GDTAA) is a rare vascular disease char-acterized by an aortic diameter exceeding 10 cm. GDTAA carries a significant risk of rupture and mortality and requires timely diagnosis and intervention. Despite the clinical severity of the disease, the literature on GDTAA remains sparse, particularly in cases with extreme aneurysmal dilatation. Case Presentation: We present the case of a 68-year-old man with a GDTAA of 14.08 × 10.04 cm, one of the largest ever reported. The patient initially presented with recurrent syncope, chronic cough and fatigue. Imaging studies, including Computed Tomography (CT) angiography, revealed a massive aneurysmal dilatation in the distal post-arch segment of the descending aorta with compression of the trachea and bronchi. The patient underwent a successful open surgical repair with a Dacron graft and simultaneous Coronary Artery Bypass Grafting (CABG). Postoperative complications included respiratory acidosis, emphysema and transient haemodynamic instability, which were effectively treated. The patient was discharged in a stable condition on the tenth postoperative day. Conclusion: This case highlights the importance of early recognition and surgical intervention in GDTAA in order to prevent catastrophic consequences. Comprehensive preoperative evaluation, careful surgical plan-ning and attentive postoperative care are essential for optimal recovery. Our results emphasise the importance of modern imaging techniques for accurate anatomical assessment and risk stratification in patients with extreme aneurysm growth. Further research is needed to establish standardised protocols for the treatment of GDTAA.

The use of cardioplegia not only achieves cardiac arrest but also minimizes ischemic/reperfusion (I/R) injury, potentially improving short- or long-term outcomes. The aim of this study was to evaluate the impact of different cardioplegic solutions - del Nido, Custodiol HTK and St. Thomas on genes expression and cytokines response in an immature rat heart model of I/R using the Langendorff preparation. Expression of genes which are involved in cell cycle, proliferation, apoptosis resistance and response to hypoxia were determined in cardiac tissue, as well as levels pro/anti-inflammatory cytokines were measured.

Surgical therapy for aortic valve endocarditis can be complicated by paravalvular abscess formation, which is associated with high morbidity and mortality. We report a case of complicated infective endocarditis treated using a delayed sternalclosure (DSC) strategy. DSC after cardiac surgery may be an effective option in managing complicated aortic root endocarditis. On admission, a 60-year-old male presented with symptoms of heart failure and a high-grade fever of unknown origin. He had previously undergone aortic valve reimplantation (David procedure) 10 years earlier for aortic regurgitation and root dilation. Transesophageal echocardiography and contrast-enhanced computed tomography confirmed a para-aortic infiltrate and vegetation on the free margin of the right coronary cusp. The patient underwent explantation of the infected Valsalva prosthesis with thorough debridement of the surrounding infected native aortic root tissues. Due to the extensive spread of infection, DSC with mediastinal drainage was performed. Mediastinal re-exploration and irrigation with Betadine solution were conducted for meticulous washing of all infected areas. The patient’s postoperative course was uneventful, with preserved valve function and no recurrence of abscess at 3-year follow-up. DSC can be considered a therapeutic option in advanced cases of infective endocarditis.

Introduction: Minor defects in the mitochondrial ATP-generating system and post-cardioplegia oxidative phosphorylation can negatively impact cardiac function in immature hearts. This study aimed to examine the mitochondrial respiratory pathway using three different cardioplegic solutions (Custodiol HTK, St. Thomas, and Del Nido) during moderate (1 h) and long (3 h) ischemic periods.

Motivation and aim: design a model of sponge and gel using biocompatible materials and innovative methods to effectively stop massive bleeding Materials and methods: Chitosan powder (Low, Medium, High mol. weight), Gallic Acid, Gelatin. Results: The combination of chitosan, gallic acid, gelatine, and NaCl can potentially be used for stoppingmassive bleeding due to their hemostatic, antimicrobial, and wound-healing properties. Indeed, the combination of chitosan, gallic acid, gelatin, and NaCl holds promise for the development of a hemostatic formulation to stop massive bleeding. Each component brings unique properties that contribute to the overall efficacy of the formulation. Here's a breakdown of their potential contribution: Chitosan: Chitosan has inherent hemostatic properties due to its positive charge and ability to interact with negatively charged blood cells and tissues. (Dai T., et al. 2011). It forms a gel-like matrix upon contact with blood, facilitating clot formation and promoting hemostasis. Chitosan also possesses antimicrobial properties, which can help prevent infection in the wound site. Gallic Acid: Gallic acid is a phenolic compound known for its antioxidant and antimicrobial activities. It can enhance the hemostatic effect of chitosan by promoting platelet aggregation and clot formation. Additionally, its antimicrobial properties can help reduce the risk of infection, which is crucial in wound healing. Gelatin: Gelatin is a protein derived from collagen and has been widely used in wound dressings and hemostatic materials. It provides mechanical strength to the formulation and can aid in the adhesion of the gel to the wound site. Gelatin also supports tissue regeneration and wound healing processes. NaCl: Sodium chloride (NaCl) can affect the osmotic balance and swelling behavior of the gel formulation. It can help regulate the release of active components, such as chitosan and gallic acid, and potentially enhance their effectiveness in promoting hemostasis and wound healing. Conclusion: In conclusion, this practice aimed to explore the creation of a gel for stopping massive hemorrhage using chitosan asthe main component. By examining the literature on gels and methods of creating them based on chitosan, a better understanding of the properties and potential applications of chitosan in hemostasis was gained. Through the evaluation of possible compositions, it was determined that a combination of chitosan, gallic acid, gelatin, and NaCl could be a promising formulation for achieving hemostasis. Chitosan offers hemostatic properties and promotes clot formation, while gallic acid exhibits antimicrobial activity and supports wound healing. Gelatin provides structural integrity and contributes to the gel's physical properties, and NaCl enhances mechanical strength and stability. Based on this information, a strategy for preparing the gel was designed, which involved dissolving chitosan in a suitable solvent to create a chitosan solution, incorporating gallic acid into the solution, preparing a gelatin solution, and gradually combining the chitosan-gallic acid mixture with the gelatin solution. NaCl was added to enhance the gel's mechanical properties. To assess the gel's effectiveness, it was tested on Gelospan 4% as an artificial blood substitute, simulating bleeding conditions. The gel's hemostatic properties, including clotting time, clot formation, and bleeding control, were evaluated. In summary, this project provides valuable insights into the design and preparation of a chitosan-based gel for stopping massive hemorrhage. The combination of chitosan, gallic acid, gelatin, and NaCl shows promise in achieving effective hemostasis. Further research and experimentation are warranted to validate the efficacy and safety of this gel formulation and explore its potential applications in clinical settings. Acknowledgements: The study is supported by Vytautas Magnus University. Kaunas, Lithuania.

Background. Perioperative blood loss in cardiac surgery remains a significant clinical challenge as there is no “gold standard” for its accurate assessment [1, 2]. Conventional volume-based methods often underestimate or overestimate actual blood loss [3], especially given individual differences in body mass and chest tubes composition (haemorrhagic vs. serous) [4]. We hypothesized that blood loss could be more accurately calculated using the Hb/kg index in terms of haemoglobin (Hb) mass loss per kilogram the patient's body weight. Objective: To develop a novel approach for calculating actual blood loss using the Hb/kg index. Methods. We studied 195 patients undergoing cardiac surgery over 13 months (October 2023–November 2024). The Hb/kg index was calculated using intraoperative Hb loss, Hb loss via chest tubes, packed red blood cell transfusions, and patient weight. Eighty-six additional clinical predictors were analyzed using conventional statistics and machine learning algorithms, including Linear Regression, Lasso, Lasso-OLS, Support Vector Machine, k-Nearest Neighbors, Decision Tree, XGBoost, and Deep Neural Network. Predictors with statistically significant Spearman correlations with the Hb/kg index were included for further analysis. Results: Lasso regression achieved the best overall performance in predicting Hb/kg index. It yielded the lowest mean squared error (0.08 ± 0.04), and mean absolute percentage error (0.18 ± 0.10), with the highest correlation (0.92 ± 0.06) and R² score (0.82 ± 0.13). BMI showed a significant negative relationship (-0.018, p < 0.001). Postoperative Hb and haematocrit values had negative correlation (-0.69, p<0.001 and -0.07, p<0.015), while initial Hb was positively correlated (0.85, p<0.001). Conclusion: This method provides a more reliable and clinically relevant tool to calculate actual blood loss and allows for a more precise assessment and treatment. This approach could be a robust research tool, although further studies are needed to demonstrate the way serves as a predictor of surgical and clinical outcomes.

Introduction Perioperative blood loss in cardiac surgery is still a significant problem [1]. There is no gold standard method to assess actual blood loss [2]. Traditional methods are based on volumetric measurement, which can be inaccurate as they can be under- or overestimated [3]. It is important to understand how the same amount of blood loss affects hemodynamics and postoperative complications in patients with different body mass [4]. Moreover, the fluid draining from the chest tube can be either haemorrhagic, serous or a combination of both [5]. We hypothesized and calculated blood loss using the Hb/kg index, which is based on hemoglobin loss per kilogram and proved to be a more accurate method of calculating actual blood loss. Aim To develop an empirical formula and a novel approach to calculate actual blood loss in terms of hemoglobin loss per kilogram (Hb/kg index). Methods In a prospective observational study, a total of 195 patients who underwent cardiac surgery with cardiopulmonary bypass were included over a period of 13 months (October 2023- November 2024). To calculate the Hb/kg index, hemoglobin loss via chest tube drainage, intraoperative hemoglobin loss, transfusion of packed red blood cells and patient weight were taken into account. An analysis of 86 predictors of the Hb/kg index was performed. Correlation coefficients Pearson r and Spearman rho between the predictors and the Hb/kg index were computed. Predictors that showed statistically significant Spearman correlations were selected for further analysis in Robust Linear Regression model. Results The robust linear regression model was fitted using Huber’s T norm estimator in Ordinary Least Squares (OLS). The determination coefficient R-squared was equal 0.983 and indicated that 98% of the variance in the Hb/kg index was explained by the predictors. The adjusted R-squared was equal 0.981. The linear regression model was statistically significant, F(27,167) = 366.3, p < 0.001. The linear regression analysis revealed several significant predictors of the Hb/kg index. Body mass index (-0.0303, p < 0.001) showed a significant negative relationship, indicating that low body mass index leads to an increase in the Hb/kg index. Predictors such as hemoglobin mass before surgery (0.0430, p < 0.001), hemoglobin loss via chest tube (0.0110, p < 0.001) and intraoperative hemoglobin loss (0.0033, p < 0.001) were found to be highly significant and positively correlated. Conversely, transfusion of hemoglobin mass (packed red blood cells) showed significant negative effects (-0.0136, p < 0.001). Conclusions This method provides a more reliable and clinically relevant tool for calculation actual blood loss, providing a more precise and individualized evaluation. This approach could be a robust research tool, although further studies are needed to demonstrate its reliability.