Estimations of the frequency of acute kidney injury in SARS-CoV-2 (COVID-19) coronavirus disease are very diverse. The literature data is highly inconsistent and shows AKI ranging from 0.5 to 80%.
The objective: to analyze the incidence of renal dysfunction in COVID-19 patients and assess the significance of systemic inflammation for its development.
Subjects and methods: The analysis was performed basing on data of 3,806 patients with COVID-19 treated at the Pavlov State Medical University, 395 of them were admitted to the intensive care units (ICU). The criterion for establishing renal dysfunction (RD) is the increase in blood creatinine level above the upper limit of reference values (0.115 mmol/l). Patients with end-stage chronic kidney disease who needed to continue routine long-term dialysis were not included in the study. We analyzed the incidence of renal dysfunction, changes in blood levels of creatinine, urea, and electrolytes during 8 days. In addition, glomerular filtration rate, diuresis volume, levels of hematocrit, hemoglobin, LDH, CRP, ferritin, and procalcitonin were evaluated.
Results. The frequency of RD among all patients was 19.0%, among patients in the ICU – 41.0%. In 79% and 81%, respectively, it was detected on the first day of hospitalization. The increase in the number of patients with RD and the aggravation of the existing dysfunction occurred after 6 days. At the initial stage of the disease, the manifestations of RD in most cases were not expressed even in those with an unfavorable course of the disease but the level of creatinine showed a weak but significant (p < 0.5) correlation with changes in CRP (r = 0.110), ferritin (r = 0.137), and procalcitonin (PCT, r = 0.418). The difference in the level of creatinine in patients with PСT level above and below 0.5 ng/ml was observed on the first day only; the value of this parameter returned to normal faster in the subgroup of patients whose procalcitonin level did not exceed 0.5 ng/ml.
Conclusion. In case of the signs indicative of RD, it is advisable to distinguish between primary and secondary injury. In the first case, it is primarily due to systemic inflammation, in the second case it is caused by additional impact of other aggressive factors. This will make it possible to clarify the renal and non-renal indications for renal replacement therapy (RRT) in patients with COVID-19, and to evaluate the results adequately since the effectiveness of RRT at different stages of the disease cannot be the same.

With a traditional approach to treatment of hypoxemic respiratory failure, it is believed that SpO₂ reduction below 88-90% during oxygen therapy requires emergency care including invasive mechanical ventilation. However, the manifestations of hypoxemic respiratory failure in COVID-19 patients have certain features that have led to the change in the traditional respiratory support procedure. The therapeutic goals of respiratory support in this category of patients require clarification.
The objective: in patients with COVID-19, to study the relationship of transcutaneous saturation values with clinical indicators that characterize ARF, the state of acid-base balance and blood gas composition.
Subjects and methods. A multicenter prospective observational study included 90 COVID-19 patients treated in ICU whose transcutaneous saturation (SpO₂) values were below 93% despite treatment. Depending on the degree of impaired oxygenation, patients underwent oxygen therapy through a mask or nasal cannula, high-flow oxygenation or non-invasive ventilation, while it was not always possible to achieve the target values of oxygenation parameters. The patients were divided into the following groups: Group 1 ‒ SpO₂ above 93%, Group 2 ‒ SpO₂ within 93–90%, Group 3 ‒ SpO₂ within 85–89%, Group 4‒ SpO₂ within 80–84%, Group 5 ‒ SpO₂ within 75–79%, and Group 6 – below 75%.
Results. It was revealed that during ARF management by noninvasive methods, different values of transcutaneous saturation and corresponding changes in the acid-base balance (ABB) and blood gas composition were determined When transcutaneous saturation (SpO₂) decreased to 85%, there was a corresponding moderate decrease in PaO₂ while no metabolic changes occurred. As a rule, there were no obvious clinical signs of respiratory failure (silent hypoxia). In patients with SpO₂ reduction down 80–85%, clinical signs of respiratory failure (dyspnea, tachypnea, agitation) and, as a rule, a moderate increase in PаCO₂ with the development of respiratory acidosis and compensatory metabolic alkalosis were noted. When SpO₂ decreased down to 75–79%, arterial hypoxemia was usually accompanied by moderate hypercapnia and the development of decompensated mixed acidosis and venous desaturation as well as increased lactate levels. With transcutaneous saturation going below 74%, these changes were even more pronounced and were observed in all patients of this group.
Conclusion. The revealed changes are mostly consistent with generally accepted ideas about the relationship between values of transcutaneous saturation and blood gas composition and parameters of blood ABB in the case of ARF. Reduction of transcutaneous saturation down to 85% not accompanied by pronounced clinical signs of respiratory failure (dyspnea, tachypnea, agitation), development of acidosis and venous desaturation, and the elevated lactate level can be regarded as relatively safe.

Spontaneous pneumomediastinum is a rare complication of viral pneumonia. The prevalence of pneumomediastinum among coronavirus infection patients is unknown.
Subjects and methods. Three cases of spontaneous pneumomediastinum among the COVID-19 pneumonia patients were analyzed. The researchers investigated and compared clinical, radiological and laboratory data.
Results. According to the research results, no correlation was found between the development of pneumomediastinum and changes in values of blood laboratory tests. As well as there were no signs of correlation between drug treatment and pneumomediastinum frequency.
Conclusion: The researchers suggest that the leading cause of spontaneous pneumomediastinum is viral pneumonia-associated severe alveolar damage.

Early prediction of disease severity helps clinicians prevent adverse events and/or minimize losses in the event of a life-threatening complication. This provision fully applies to refractory septic shock, in which norepinephrine administration at a dose exceeding 0.5 μg/kg-1/min-1 is needed to maintain mean arterial pressure.
The objective: to determine predictors of lethal outcomes in patients with refractory septic shock.
Subjects and methods. A retrospective study included 79 patients with refractory septic shock aged from 42 to 74 years (59.7 ± 7.8), with severity of the condition as per SOFA varying from 8 to 16 scores. The predictive value of indicators was assessed using univariate and multivariate analyses.
Results. In multivariate analysis, the only significant predictor of an unfavorable outcome was the SOFA score (adj. OR: 1.626 [95% CI: 1.313; 2.014], p < 0.001). Other putative indicators (age, oxygenation index, lactate and procalcitonin concentrations, and norepinephrine dose) had no predictive value.
Conclusion: The SOFA score is an independent predictor of lethality in adult patients with refractory septic shock (аdj. OR: 1.26 [95% CI: 1.313; 2.014], p < 0.001). According to the results of the ROC analysis, along with SOFA, norepinephrine dose was also a significant predictor (AUC 0.989 [95% CI 0.934; 1.000], p < 0.001).

The objective: to compare efficacy and safety of Intellivent-ASV® with conventional ventilation modes during weaning in the patients after cardiac surgery.
Subjects and methods. In this randomized controlled trial, 40 adult patients were ventilated with conventional ventilation modes and 40 with Intellivent-ASV after uncomplicated cardiac surgery. Eight physicians were involved in the study.
Care of both groups was standardized, except for the modes of postoperative ventilation.
We compared:
- The physician’s workload, through accounting number of manual ventilator settings and time they spent near the ventilator in every group,
- Duration of tracheal intubation in ICU,
- Evaluation of ventilation safety by considering driving pressure, mechanical power, positive end expiratory pressure, and tidal volume level,
- The frequency of adverse events, postoperative complications, and lethality.
Results. There were significant differences in the duration of respiratory support in ICU: 226 ± 31 min (Intellivent Group) vs 271 ± 78 min (Control Group) (p = 0.0013).
In Intellivent Group, the number of manual ventilator settings and time spent by physicians near the ventilator before tracheal extubation were significantly lower: 0 vs 4 (2–6), and 35 (25–53) sec vs 164 ± 69 sec respectively (p < 0.001 in both cases).
Intellivent-ASV provided significantly more protective ventilation through reduction in the driving pressure, tidal volume, FiO₂ and PEEP levels but no difference was noted between paO2/FiO2 ratio. ∆P and Vt were significantly lower in Intellivent Group – ∆P on mechanical ventilation was 6 (5–7) cm H2O vs 7.25 (6.5–9.5) cm H₂O (p < 0.001); Vt on mechanical ventilation was 6 (5.2–7) vs 7 (6–9.5) ml/kg/PBW (p = 0.000003). PEEP and FiO₂ levels were also significantly lower in Intellivent Group, PEEP on mechanical ventilation was 5 (5–7.5) cm H₂O vs 7 (5–11.5) cm H2O and FiO₂ level was 26 (22–30) % vs 34 (30–40) %.
There were no significant differences between the groups in frequency of adverse events and duration of ICU and hospital stay.
Conclusion. Application of Intellivent-ASV mode after uncomplicated cardiac surgery provides more protective mechanical ventilation and reduces the physician’s workload without compromising the quality of respiratory support and safety of patients.

Some patients with severe burn injury have a high risk of developing acute respiratory failure, the cause of which may be interstitial pulmonary edema caused by inadequate infusion therapy.
The objective: to evaluate the effectiveness of high-flow oxygen therapy (HFOT) in acute parenchymatous respiratory failure in burn patients.
Subjects and methods. The prospective analysis included 74 patients with ARF in the stage of burn toxemia, without inhalation trauma, with PaO₂/FiO₂ below 300. In Main Group (37 patients), HFOT was used, while in Control Group patients received oxygenation through nasal cannula with the rate up to 15 l/min. Parameters of respiratory rate, PaO₂/FiO₂, PaCO₂, MAP, heart rate, the number of intubations, respiratory comfort were recorded within 48 hours.
Results. Main Group had higher values of oxygenation index in 48 hours of the trial (342 vs. 305.5, p = 0.02), faster normalization of blood gas composition compared to Control Group. HFOT was associated with greater respiratory comfort (8.4 vs. 5.3 VAS scores, p = 0.03), lower need in mechanical ventilation (4 vs. 11, p = 0.04).
Conclusion: HFOT is an effective method for the treatment of respiratory failure in inpatients with burns. The need for intubation decreases, it is more comfortable to be tolerated than standard methods of oxygen therapy.

The preoperative anemia in patients increases the risk of perioperative blood transfusion, myocardial infarction, ischemic stroke, acute kidney injury, and higher nosocomial and 30-day mortality, lengthens the duration of treatment, and increases the risk of re-hospitalization.
The objective: to improve treatment results of patients after revision shoulder replacement through management of preoperative anemia.
Subjects and methods. 170 medical files of patients who underwent revision shoulder replacement from 2014 to 2021 were retrospectively analyzed. On the day when they were examined by the physician, all patients had blood hemoglobin level below 130 g/l. The patients were divided into two groups that were comparable in their characteristics. Patients of the Main Group (n = 90) received preoperative preparation with iron carboxymaltate in combination with recombinant human erythropoietin 4 weeks before the expected date of surgery. Patients of the Control Group (n = 80) did not have any specific preparation.
Results. The data obtained showed that the volume of intraoperative and postoperative drainage blood loss did not differ statistically between the groups; hemoglobin blood level in patients from the Main Group was statistically significantly higher both before the surgery and on the first day after it, and no hemotransfusion was indicated. In the Control Group, a statistically significantly greater decrease in hemoglobin level was observed in the postoperative period; 3 (3.8%) patients in the Control Group required RBC-transfusion. Complications in the early postoperative period (myocardial infarction, pulmonary embolism, and cardiac arrhythmia) were significantly less frequent in the Main Group versus the Control one (4.5% of cases vs. 8.8%; p < 0.05).
Conclusion. The use of iron carboxymaltate at the dose of 1,000 mg once and, if necessary, repeatedly in 14 days in combination with recombinant human erythropoietin at the dose of 150 IU/kg allows preparing patients for revision shoulder replacement within the period from two weeks to one month. Preoperative management of anemia until the hemoglobin concentration reaches 130 g/l using the proposed regimen can significantly reduce the need for blood transfusion and frequency of somatic complications in the early postoperative period.

Diagnosis of vitamin D deficiency and its management is the most difficult problem of modern neonatology.
The objective: to study the concentration of 25(OH)D3 in newborns of St. Petersburg depending on the presence of congenital malformations (CM).
Subjects and methods. 60 newborns were examined, their gestational age made 39.4 (38-41) weeks. Children were divided into 2 groups: Group 1 – healthy children, Group 2 – children with CM.
Results. Regardless of the presence of CM, the calcifedol plasma concentration was below 15 ng/ml. It was found that children with CM whose plasma calcifedol concentration was below 8.0 ng/ml needed long-term invasive mechanical ventilation (80.0 vs 40.0 hours; p < 0.005) and longer treatment in ICU (7.0 vs 4.0; p < 0,002). Negative correlations were revealed between calcifedol concentration, duration of narcotic analgesics administration (R = -0.44; p = 0.01), duration of mechanical ventilation (R = -0.49; p = 0.003) and stay in ICU (R = -0.54; p = 0.001).
Conclusion. The most pronounced deficiency of calcifedol was in children with severe CM requiring long-term treatment in ICU.

The objective: to evaluate the international practice of using calcium salts when weaning from cardiopulmonary bypass after cardiac surgery in adult patients.
Design: a multiple-choice survey about the current practice of calcium salts use when weaning from cardiopulmonary bypass based on the SurveyMonkey platform.
Participants: cardiac surgical hospitals around the world.
Estimation and main results. Totally 112 emails were sent to Russian and foreign centers inviting them to participate in the survey. 100 centers from 32 countries replied to this request. Generally, the majority of centers (88%) administer calcium salts during surgery with cardiopulmonary bypass, and in 71 (71%) centers out of 100, calcium salts are used to improve hemodynamics. Among 88 centers that use calcium salts during surgery, 66% (58/88) of respondents use calcium chloride, 22% (19/88) use calcium gluconate, and 12% (11/88) use both drugs. Most centers (55 (77%) out of 71) use doses of 5 to 15 mg/kg as a bolus or infusion for 1 min.
Conclusion: Our survey shows that the majority of cardiac surgery centers use calcium in adult cardiac surgery patients especially during weaning from cardiopulmonary bypass. There is variability in the type of drug, dose, and route of administration.

Post-cardiac arrest syndrome is an extremely complex nosology, characterized by high mortality and the development of severe neurological disorders. Predicting the neurological outcome in this pathology is an urgent problem, since it allows determining the tactics of patient management and optimizing the scope of medical care, as well as preparing the patient's family members for expected results of treatment. Currently, clinical, laboratory and instrumental data are used as predictors of an unfavorable neurological outcome (e.g., pupillary responses, neuron-specific enolase levels, electroencephalography). There is no single criterion with high sensitivity and specificity for predicting neurological disorders; therefore, a multimodal approach is required. This article discusses several factors, the combination of which allows predicting the outcome of post-cardiac arrest syndrome with the greatest degree of reliability.

Refractory shock is the shock that does not respond to vasopressor therapy. Refractory shock with a short-term mortality rate of more than 50% is diagnosed in 6-7% of critically ill patients. There is an objective need to Investigate methods of intensive therapy for refractory septic shock.
The objective of the study: to analyze literature data on the intensive care of refractory septic shock.
Results. The second part of the article analyzes 37 studies, both Russian and foreign ones devoted to the intensive care of refractory shock. At present, based on the analysis of the publication, it is impossible to draw reasonable conclusions about the advantage of one or another method of intensive therapy for refractory shock (veno-venous hemofiltration, the use of angiotensin II and vasopressin, as well as methylene blue, vitamin B₁₂, ECMO) over basic therapy.

Acute pulmonary embolism (PE) is a relatively common vascular disease with potentially life-threatening complications. Right heart thrombi deteriorate the prognosis. Due to the known high lethality, such a clinical situation requires immediate diagnosis and treatment. With the existing different management options for intracardiac blood clots, the optimal one is still uncertain. The article describes the experience of therapeutic and diagnostic tactics in a patient with PE and thrombosis of two right chambers of the heart with a favorable outcome while the conservative approach was used.