Delirium in Children after Cardiac Surgery: Brain Resuscitation

This chapter presents the current data on delirium in children in the postoperative period with the correction of congenital heart defects. The analysis of the causes of delirium, according to the literature data, pathophysiology, clinical signs, and methods of diagnosis of postoperative delirium, is shown. In addition, methods for the prevention of delirium in children during cardiac surgery are presented

РОЛЬ ГИПОТЕРМИИ ДЛЯ ЦЕРЕБРОПРОТЕКЦИИ ПРИ ХИРУРГИЧЕСКОЙ КОРРЕКЦИИ ВРОЖДЕННЫХ ПОРОКОВ СЕРДЦА

HighlightsThis article is devoted to a review of studies on the mechanisms of cerebral protection and the effects of hypothermia on the patient. AbstractA large number of surgical corrections of congenital heart defects are performed around the world annually, most of them using cardiopulmonary bypass. This kind of surgery can be a pathological factor for the brain. In some patients, the kind of surgery involves the use of hypothermia. Supposedly, hypothermia should have a neuroprotective effect, however, as recent studies show, this is not always the case. This review is devoted to the mechanisms of the effect of hypothermia on the patient’s body, including not only a decrease in brain metabolism, but also a number of others. Moreover, a review of current works on the use of hypothermia in clinical practice in surgeries that do not require circulatory arrest is presented, along with an analysis of the intra- and postoperative period.Основные положенияПредставлен обзор исследований о механизмах церебропротекции и влиянии гипотермии на пациента. РезюмеЕжегодно в мире проводят большое количество хирургических коррекций врожденных пороков сердца, большую часть из них – с использованием искусственного кровообращения. Любая такая операция имеет набор патологических для головного мозга факторов, в некоторых хирургическая стратегия предполагает применение гипотермии. В частности, гипотермия должна обладать нейропротективным эффектом, однако, как показывают последние исследования, это не всегда так. Обзор посвящен механизмам влияния гипотермии на организм пациента, среди которых не только снижение метаболизма мозга, но и ряд других. Представлены актуальные работы о применении гипотермии при операциях, не требующих циркуляторного ареста, с анализом интра- и послеоперационного периода

Влияние трансфузии и гипоксии на клетки модели нейроваскулярной единицы in vitro

Up to 57% of patients develop postoperative delirium after surgery for congenital heart defects (CHD). To reduce cerebral damage in pediatric patients during CHD surgery it is important to find out what inflicts the worse damage: would it be a systemic inflammatory response (SIR) triggered by transfusion, or hypoxia developed in non-transfused patients? In vitro evaluation of hypoxia and SIR effects on the neurovascular unit (NVU) cells might contribute to finding the answer.The aim of the study was to compare the effect of varying severity hypoxia and SIR on the functional activity of NUV cells in vitro.Materials and methods. An in vitro NVU model was designed including neurons, astrocytes and endotheliocytes. The effect of hypoxia on NVU was evaluated in the control (C) and 4 study groups (H 1-4), formed based on O2 content in the medium. The C group NVU were cultivated in standard conditions: N2-75%, O2-20%, CO2-5%; H1: N2-99%, O2-1%; H2: N2- 98%, O2-2%; H3: N2-97%, O2-3 %; H4: N2-96%, O2-4%. The significance of the differences was 0.0125. The effect of interleukin-6 (IL-6) content on NVU was measured by adding to culture medium pediatric patients’ serum with known minimal or maximal SIRS-response. The assessment was made in the Control - an intact NVU model, and 2 study groups – “Minimum” and “Maximum”, i.e. samples with minimum or maximum IL-6 content in culture, respectively. The significance of the differences was 0.017. The cells were incubated at a normothermia regimen for 30 minutes. Then, the functional activity of NVU cells was evaluated by measuring transendothelial resistance (TER) for 24 hours and Lucifer Yellow (LY) permeability test at 60 and 90 minutes after the start of the experiment.Results. After incubation under hypoxic conditions, TER changes occurred in all studied groups. However, they were statistically significant only in the group with 1% oxygen content in the medium. TER decrease in this group was observed after 2, 4 and 24 hours. LY permeability also changed at 60 and 90 minutes, similarly - in NVU cultivated with 1% oxygen in the medium. Minimal TER values were documented at 4 hours after patients’ serum was added to NVU cells culture medium, and TER increased at 24 hours in both study groups. Cellular permeability to LY changed significantly after 1 hour exposure in both groups - with minimum and maximum IL-6 content in the medium. Although at 90 minutes, there was no difference between the 3 groups in LY permeability tests.Conclusion: Intensive SIR demonstrated short-term but more deleterious than hypoxia, effect on cells in the NVU model. Hypoxia disrupted functional activity of NUV cells only at 1% O 2 concentration in the medium.Частота развития послеоперационного делирия при коррекции врожденных пороков сердца (ВПС) достигает 57%. В поиске путей профилактики церебрального повреждения при коррекции ВПС у детей важным является вопрос - что опаснее: гипоксия при отказе от трансфузии или действие повышенного системного воспалительного ответа (СВО) при ее применении. Исследование действия гипоксии и СВО на клетки нейроваскулярной единицы (НВЕ) in vitro способствует решению данного вопроса.Цель исследования: сравнить влияние гипоксии различной выраженности и системного воспалительного ответа на функциональную активность клеток нейроваскулярной единицы.Материалы и методы. Сформировали in vitro модель НВЕ, состоящую из нейронов, астроцитов и эндотелиоцитов. Влияние гипоксии на НВЕ оценивали в контрольной (К) и 4 исследуемых (Г1-4) группах. Группы сформировали по содержанию О2 в среде: К – стандартные условия культивирования: N2-75%, O2-20%, CO2-5%; Г1: N2-99 %, O2-1 %; Г2: N2-98 %, O2-2 %; Г3: N2-97 %, O2-3 %; Г4: N2-96 %, O2-4 %. Значимость различий составила 0,0125. Влияние содержания интерлейкина-6 (ИЛ-6) на НВЕ определяли при культивировании клеток с добавлением сыворотки крови пациентов детского возраста с минимальным, либо максимальным напряжением СВО. Оценку провели в контрольной и 2 исследуемых группах: «Контроль» – интактная модель НВЕ; группы «Минимум» и «Максимум» - образцы с минимальным либо максимальным содержанием ИЛ-6 в культуре соответственно. Значимость различий составила 0,017. Инкубацию клеток проводили в режиме нормотермии в течение 30 минут. Затем оценивали функциональную активность клеток НВЕ методом измерения трансэндотелиального сопротивления (ТЭС) в течение 24 часов и измерения проницаемости для красителя Lucifer Yellow (LY) через 60 и 90 минут от начала эксперимента.Результаты. После инкубации в условиях гипоксии изменения ТЭС наступили во всех исследуемых группах клеток. Однако, только в группе с 1% содержанием кислорода в среде они были статистически значимы. Снижения ТЭС в данной группе наблюдали через 2, 4 и 24 часа. Проницаемость клеток для красителя LY изменилась через 60 и 90 минут также только в условиях их инкубации в среде с 1 % кислородом. При культивировании клеток НВЕ с сывороткой крови пациентов выявили минимальные значения ТЭС через 4 часа и их дальнейшее повышение через 24 часа для обеих исследуемых групп НВЕ. Проницаемость клеток для LY значительно изменилась к 60-й минуте как в группе с минимальным, так и с максимальным содержанием ИЛ-6 в среде. При этом к 90-й минуте различий этого показателя в исследуемых группах и в контрольной группе уже не наблюдали.Заключение. Напряженный СВО оказал более выраженное, но кратковременное действие на модель НВЕ, чем гипоксия. Гипоксия нарушила функциональную активность НВЕ только при концентрации кислорода в среде - 1 %

Refraining from Packed Red Blood Cells in Cardiopulmonary Bypass Priming as a Method of Neuroprotection in Pediatric Cardiac Surgery

Congenital heart defect (CHD) surgeries are performed with cardiopulmonary bypass (CPB) and are complicated by several factors that affect the child’s brain. However, to date, the number of studies on brain protection in cardiac surgery remains small. The aim of this study was to assess the impact of refraining from using packed red blood cells (PRBCs) in priming solutions in children with congenital defects (CHDs) who require surgical interventions using CPB to prevent brain injury in the postoperative period. Material and methods: This study included 40 children, and the mean age was 14 (12–22.5) months and the mean weight was 8.8 (7.25–11) kg. All patients underwent CHD closure using CPB. The patients were divided into two groups depending on the use of PRBCs in the priming solution. Brain injury was assessed using three specific blood serum markers, namely S100 calcium-binding protein β (S100β), neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) before surgery, after the completion of CPB and 16 h after surgery (first, second and third control points). Markers of systemic inflammatory response were also analyzed, including interleukin-1, -6, -10 and tumor necrosis factor alpha (TNF-α). A clinical assessment of brain injury was carried out using a valid, rapid, observational tool for screening delirium in children of this age group, i.e., “Cornell Assessment of Pediatric Delirium”. Results: Factors of the intra- and postoperative period were analyzed, such as hemoglobin levels, oxygen delivery (cerebral tissue oxygenation, blood lactate level and venous oxygen saturation) and indicators of organ dysfunction (creatinine, urea, bilirubin levels, duration of CPB and length of stay in the ICU). Following the procedure, there were no significant differences between the groups and all indicators were within the reference values, thus demonstrating the safety of CHD closure without transfusion. Moreover, the highest level of specific markers of brain injury were noted immediately after the completion of CPB in both groups. The concentration of all three markers was significantly higher in the group with transfusion after the completion of CPB. Moreover, GFAP levels were higher in the transfusion group and 16 h after surgery. Conclusions: The results of the study show the safety and effectiveness of brain injury prevention strategies that consist of not conducting PRBC transfusion

Mitochondrial DNA as a Candidate Marker of Multiple Organ Failure after Cardiac Surgery

Assess the level of mitochondrial DNA depending on the presence of multiple organ failure in patients after heart surgery. The study included 60 patients who underwent surgical treatment of valvular heart disease using cardiopulmonary bypass. Uncomplicated patients were included in the 1st group (n = 30), patients with complications and multiple organ failure (MOF) were included in the 2nd group (n = 30). Serum mtDNA levels were determined by quantitative real-time polymerase chain reaction with fluorescent dyes. Mitochondrial DNA gene expression did not differ between group before surgery. Immediately after the intervention, cytochrome B gene expression was higher in the group with MOF, and it remained high during entire follow-up period. A similar trend was observed in cytochrome oxidase gene expression. Increased NADH levels of gene expressions during the first postoperative day were noted in both groups, the expression showed tendency to increase on the third postoperative day. mtDNA gene expression in the “MOF present” group remained at a higher level compared with the group without complications. A positive correlation was reveled between the severity of MOF according to SOFA score and the level of mtDNA (r = 0.45; p = 0.028) for the end-point “First day”. The ROC analysis showed that mtDNA circulating in plasma (AUC = 0.605) can be a predictor of MOF development. The level of mtDNA significantly increases in case of MOF, irrespective of its cause. (2) The expression of mtDNA genes correlates with the level of MOF severity on the SOFA score

Cardiopulmonary bypass without the use of donor blood components in heart surgery in an 8-kg infant: case report

The issue of rejecting donor blood components intraoperatively in children with congenital heart defects is widely discussed in the world literature. This is primarily due to the presence of a low volume of circulating blood, which leads to excessive hemodilution during artificial circulation. The purpose of this report is to demonstrate the safety and effectiveness of conducting operations associated with congenital heart defects without the use of transfusion of donor blood components. A case of surgical treatment of the interatrial septum defect in an 11-month (8 kg) infant with the use of cardiopulmonary bypass and a set of measures enabling to abandon transfusion media is presented. Retrograde filling of the oxygenator and maximum minimization of the extracorporeal circuit were used to reduce the primary volume. To ensure the required volume of blood in the cardiotomy tank, dosed vacuum was applied. Clinical and laboratory characteristics of the intraoperative and postoperative periods are given, which demonstrate sufficient oxygen supply of the organism, absence of anemia and any organ dysfunctions, as well as a low level of the systemic inflammatory response, once again confirming the immediate advantages of blood-saving technologies. Following the correction of congenital heart disease, the infant was transferred to a specialized surgical department on the second day. The outcome of the clinical case was the infant’s recovery and discharge from the hospital.Received 17 April 2018. Revised 17 June 2018. Accepted 18 June 2018.Informed consent: The informed consent to use the infant’s medical data for scientific purposes was obtained from his legal representative.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.</p

Acute kidney disease beyond day 7 after major surgery: a secondary analysis of the EPIS-AKI trial

Purpose: Acute kidney disease (AKD) is a significant health care burden worldwide. However, little is known about this complication after major surgery. Methods: We conducted an international prospective, observational, multi-center study among patients undergoing major surgery. The primary study endpoint was the incidence of AKD (defined as new onset of estimated glomerular filtration rate (eCFR) &lt; 60&nbsp;ml/min/1.73&nbsp;m2 present on day 7 or later) among survivors. Secondary endpoints included the relationship between early postoperative acute kidney injury (AKI) (within 72&nbsp;h after major surgery) and subsequent AKD, the identification of risk factors for AKD, and the rate of chronic kidney disease (CKD) progression in patients with pre-existing CKD. Results: We studied 9510 patients without pre-existing CKD. Of these, 940 (9.9%) developed AKD after 7&nbsp;days of whom 34.1% experiencing an episode of early postoperative-AKI. Rates of AKD after 7&nbsp;days significantly increased with the severity (19.1% Kidney Disease Improving Global Outcomes [KDIGO] 1, 24.5% KDIGO2, 34.3% KDIGO3; P &lt; 0.001) and duration (15.5% transient vs 38.3% persistent AKI; P &lt; 0.001) of early postoperative-AKI. Independent risk factors for AKD included early postoperative-AKI, exposure to perioperative nephrotoxic agents, and postoperative pneumonia. Early postoperative-AKI carried an independent odds ratio for AKD of 2.64 (95% confidence interval [CI] 2.21-3.15). Of 663 patients with pre-existing CKD, 42 (6.3%) had worsening CKD at day 90. In patients with CKD and an episode of early AKI, CKD progression occurred in 11.6%. Conclusion: One in ten major surgery patients developed AKD beyond 7&nbsp;days after surgery, in most cases without an episode of early postoperative-AKI. However, early postoperative-AKI severity and duration were associated with an increased rate of AKD and early postoperative-AKI was strongly associated with AKD independent of all other potential risk factors

Epidemiology of surgery associated acute kidney injury (EPIS-AKI): a prospective international observational multi-center clinical study

Purpose: The incidence, patient features, risk factors and outcomes of surgery-associated postoperative acute kidney injury (PO-AKI) across different countries and health care systems is unclear. Methods: We conducted an international prospective, observational, multi-center study in 30 countries in patients undergoing major surgery (&gt; 2-h duration and postoperative intensive care unit (ICU) or high dependency unit admission). The primary endpoint was the occurrence of PO-AKI within 72&nbsp;h of surgery defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Secondary endpoints included PO-AKI severity and duration, use of renal replacement therapy (RRT), mortality, and ICU and hospital length of stay. Results: We studied 10,568 patients and 1945 (18.4%) developed PO-AKI (1236 (63.5%) KDIGO stage 1500 (25.7%) KDIGO stage 2209 (10.7%) KDIGO stage 3). In 33.8% PO-AKI was persistent, and 170/1945 (8.7%) of patients with PO-AKI received RRT in the ICU. Patients with PO-AKI had greater ICU (6.3% vs. 0.7%) and hospital (8.6% vs. 1.4%) mortality, and longer ICU (median 2 (Q1-Q3, 1-3) days vs. 3 (Q1-Q3, 1-6) days) and hospital length of stay (median 14 (Q1-Q3, 9-24) days vs. 10 (Q1-Q3, 7-17) days). Risk factors for PO-AKI included older age, comorbidities (hypertension, diabetes, chronic kidney disease), type, duration and urgency of surgery as well as intraoperative vasopressors, and aminoglycosides administration. Conclusion: In a comprehensive multinational study, approximately one in five patients develop PO-AKI after major surgery. Increasing severity of PO-AKI is associated with a progressive increase in adverse outcomes. Our findings indicate that PO-AKI represents a significant burden for health care worldwide