ObjectiveThis study was carried out to assess whether the remote ischemic preconditioning (RIPC) affects the inflammatory response in patients undergoing the aortic valve replacement. Methods Twenty seven patients were included into the prospective randomised study. In all cases the aortic valve replacement was performed due to the aortic stenosis under cardiopulmonary bypass (CPB). 13 patients of main group received RIPC and 14 patients formed control group. Anaesthesia was maintained either by propofol and fentanyl (7 patients in the control group, 8 patients in the RIPC group) or by sevoflurane and fentanyl (7 patients in the control group, 5 patients in the RIPC group). RIPC was induced by three 5-min cycles of lower limb ischemia and reperfusion after anaesthesia induction. Cytokines (interleukin-8 (IL-8), interleukin-6 (IL-6)) were analysed at baseline, 30 min, 12 h, 24 h and 48 h after CPB completion. Quantitative data were presented as median (25th–75th percentile). According to nonparametrically distribution, data were assessed by the Mann-Whitney U-test, a P value < 0.05 was considered as significant. Results Our study displayed the significant increase in cytokines levels after CPB completion in both groups. There were no statistical differences in IL-8 and IL-6 concentrations between groups at 30 min and 12 h after CPB. Unexpectedly we found the significantly higher IL-8 activity in the RIPC group at 24 h and 48 h after CPB: it was 12.3 (7.9; 16.5) pg/mL vs. 6.5 (5.5; 10.4) pg/mL in the control group, p = 0.03 at 24 h and 10.6 (5.8; 13.2) pg/mL vs. 5.5 (4.5; 6.1) pg/mL in the control group, p = 0.02 at 48 h. The same tendency was found in IL-6 activity, however statistical significance between the RIPC group and the control one was not confirmed: 27.6 (15.1; 38.5) pg/mL vs. 15.3 (10.5; 28.8) pg/mL, respectively (p = 0.32) at 24 h and 17.1 (13.0; 27.3) pg/mL vs. 9.9 (6.8; 17.2) pg/mL, respectively (p = 0.14) at 48 h. Conclusions This pilot study indicates surprisingly that RIPC may enhance inflammatory response after CPB. Our data suggest that large clinical trials assessing the effects of RIPC on the inflammatory response should be performed in order to study the underlying mechanisms.

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Background Hyperlactatemia is a well recognised marker of circulatory failure [1]. Several studies have shown a strong correlation between blood lactate levels and the risk of morbidity and mortality in varying clinical situations such as circulatory shock, septic shock, severe hypoxemia, liver failure, diabetes mellitus, and others [2]. After cardiac surgery, Hyperlactatemia is relatively common and is associated with morbidity and mortality. Hyperlactatemia occurs during cardiopulmonary bypass in patients undergoing operations for congenital cardiac disease and may be an early indicator for postoperative morbidity and mortality. It is a well-known fact that tissue hypoperfusion and inadequate oxygen delivery are associated with lactic acidosis owing to anaerobic metabolism [3]. The aim of the present study is to estimate the frequency and to reveal predictors of heperlactatemia occurrence in children with congenital heart diseases in the early postoperative period. Methods This prospective study was spent in our centre between March and September 2007. Seventy two patients with congenital heart diseases operated in artificial blood circulation conditions from 1 till 17 years old were included in to the research. The study design was approved by the centre ethical committee. Written voluntary consent to participation in the scientific programme was signed by children’s parents. The induction to anaesthesia was performed in the presence of parents and includes the following components: Ketamin 7 mg/kg; Relanium 0.25 mg/kg; Atropine 0.015 mg/kg. After an approach of proof sedative effect the child was delivered to the operation room. Myoplegia was carried out by an intravenous injection of pipikuronium bromide 0.1 mg/kg. Artificial lungs ventilation was carried by Datex Ohmeda ADU AS-5 (Finland) (IPPV-mode). Results We have obtained the following data: increase in lactate concentration > 5 mmol/l was marked in 2.37% blood samples. Time intervals analysis has shown, that maximal lactate concentration were observed in 7–11 hours after operation. There were no cases of heperlactatemia after 24 hours after operation. Having investigated interrelation between lactate and glucose concentration, we have found statistically authentic differences in glucose level > 9 mmol/l (r = 0.56). This interrelation was traced only in two time intervals: 1–6 and 7–11 hours after operation. Conclusions Metabolic infringements in children with congenital heart diseases operated in artificial blood circulation conditions are observed in small percent of cases. Lactate concentration peak is observed in 7–11 hours interval after operation. There is no significant interrelation between artificial circulation time and heperlactatemia intensity in early postoperative period.

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