Vol 6, No 2 (2025)

BACKGROUND: Nephrectomy with thrombectomy of the inferior vena cava is an effective treatment for kidney cancer complicated by tumor thrombus (TT). However, this surgical intervention carries a high risk of severe homeostatic disturbances in the early postoperative period.

AIM: This study aimed to evaluate the changes in metabolic parameters in the early postoperative period in patients undergoing nephrectomy with inferior vena cava thrombectomy without extracorporeal circulation.

METHODS: This observational study included 682 patients who underwent nephrectomy with thrombectomy for kidney cancer with TT. According to the Mayo Clinic classification, patients were divided into three groups based on the proximal extent of TT: Infrahepatic (InH, levels I and II), Retrohepatic (RH, level III), and Supradiaphragmatic (SD, level IV). Complete blood count, blood biochemistry, and coagulation profile were assessed at three time points: stage 1 (S1), preoperatively; stage 2 (S2), morning of postoperative day 1; and stage 3 (S3), morning of postoperative day 2.

RESULTS: Analysis of hematology, coagulation, and biochemistry parameters revealed significant postoperative changes. A progressive decrease in platelet concentration was observed from stage to stage, with intergroup differences most pronounced in the InH group. Erythrocyte concentration significantly decreased at S3 in the RH group. Fibrinogen concentration demonstrated a complex pattern. The highest values were recorded in the InH group at S1. Significant differences between all groups persisted at subsequent stages, whereas key coagulation parameters remained stable.

The biochemistry profile was characterized by a significant increase in urea and creatinine concentrations by S3 in all groups. Total bilirubin, total protein, and albumin concentrations significantly decreased after S1. Alanine aminotransferase and aspartate aminotransferase activities differed significantly between stages but not between groups. Pancreatic amylase concentration did not change. Despite statistically significant fluctuations, plasma lactate concentration remained within reference ranges in all cases.

CONCLUSION: The frequency and severity of homeostatic disturbances after nephrectomy with thrombectomy of inferior vena cava directly correlate with the extent of the TT.

Malnutrition substantially affects the outcomes of antitumor therapy in patients with cancer. Nutritional support is often prescribed subjectively, which may lead to errors in determining the need for artificial nutrition, route of administration, and composition of nutritional therapy. While machine learning and artificial intelligence are increasingly being incorporated into clinical practice, their application in nutritional support remains rather limited. Here, we conducted a review to highlight the current state of this issue.

We analyzed publications indexed in MEDLINE, Web of Science, and the Scientific Electronic Library (eLibrary) from 2021 to 2024 addressing the use of artificial intelligence — namely, machine learning algorithms — for early identification of protein–energy deficiency and prediction of its development in patients with cancer. The findings indicate that predictive models based on artificial intelligence, as well as models for identifying protein–energy deficiency, can be integrated into clinical decision support systems. This approach enables timely diagnosis and correction of nutritional deficiencies and helps reduce the subjectivity and limitations inherent to the conventional empirical approach to prescribing nutritional support. The review also discusses common errors encountered in the implementation of nutritional support in patients with cancer, and outlines opportunities for mitigating them through machine learning.

The analysis shows that despite considerable prospects, the use of machine learning and artificial intelligence for identifying nutritional deficiencies and delivering nutritional support in real clinical practice remains rather limited.

In recent decades, active longevity and increased average lifespan have received particular attention in the Russian Federation. One of the major achievements of modern medicine has been the extension of life expectancy. However, this accomplishment has been accompanied by a growing number of individuals with limited mobility, and sarcopenia is considered one of its causes. Therefore, timely identification and diagnosis of potential contributors to sarcopenia represent an important task for preventive medicine. This review summarizes data demonstrating the association between sarcopenia and vitamin D. Analysis of scientific publications indicates that vitamin D deficiency is one of the significant factors contributing to the development of sarcopenia in older adults. Recently, vitamin D has been considered a potential determinant of muscle biology that affects physical performance and plays a fundamental role in sarcopenia prevention. Evidence suggests that decreased serum vitamin D concentration may lead to destruction of muscle fibers. This condition manifests as reduced muscle strength, decreased muscle mass, and impaired skeletal muscle function, up to complete muscle atrophy. Nutritional support is essential in sarcopenia prevention and includes adequate levels of high-quality protein, leucine, creatine, and omega-3 polyunsaturated fatty acids in the daily diet.

Severe hypokalemia, defined as a serum potassium concentration below 2.5 mmol/L, is a relatively uncommon but clinically significant condition. It is often associated with a poorer prognosis in hospitalized patients. Potassium replacement in severe hypokalemia may be challenging. A major contributing factor is substantial underestimation of the deficiency when standard calculation methods are used.

A 64-year-old woman with decompensated pyloric stenosis due to gastric cancer and displacement of a previously installed stent developed severe hypokalemia following persistent vomiting. Despite potassium replacement according to the British Dietetic Association’s Clinical Nutrition Guidelines commonly used for hypokalemia, both hypokalemia and symptoms of severe potassium deficiency continued to worsen. The patient was transferred to the intensive care unit with progressive weakness, muscle cramps, and gastrointestinal paresis, where a simplified protocol for rapid potassium replacement was used. Normokalemia and resolution of severe manifestations of potassium deficiency were achieved within 2 days.

In cases of severe potassium deficiency, it is essential to diagnose hypokalemia and monitor serum potassium concentrations during correction and also to accurately estimate the potassium dose required to replenish the deficiency. Standard potassium deficiency calculations used for mild or moderate hypokalemia substantially underestimate the actual deficiency in severe hypokalemia, resulting in inadequate correction. Existing nomograms for potassium repletion that take into account current acid–base balance are complex to use. They do not offer any advantages in clinical practice, as minor calculation errors are compensated by repeated serum potassium measurements and subsequent therapy adjustments. In severe hypokalemia, for the initial general estimation of potassium deficiency, it is convenient to consider that that each decrease in potassium concentration by 0.3 mmol/L with serum potassium below 3.5 mmol/L corresponds to a total body potassium deficit of approximately 10 mmol per 10 kilograms of body weight.