Application Of ECMO In Pediatric Critical Care Medicine And Effect Of Annexin A1Expression In Peripheral Blood Mononuclear Cells

PART I Application of ECMO in Pediatric Critical Care MedicineObjective:Extracorporeal membrane oxygenation (ECMO) is an extracorporeal life support technique that can replace of the cardiac and pulmonary function for a long time, and maintain the body’s oxygen supply of every organs for the patients of heart and lung failure in severe situation. ECMO is the key technique of extracorporeal life support system of Pediatric Critical Care Medicine(PCCM) and backward in Chinese PCCM. The data of the critical children underwent ECMO in our hospital recent years was reviewed in this study, the ECMO indication, prognosis, ECMO aid cardiopulmonary resuscitation(ECPR), complications of ECMO and CRRT during ECMO were analyzed. Hope to provide some clinical references for development of ECMO in PCCM field in China.Methods:Research personnel retrospectively analyzed clinical data collected by a standardized data collection sheet through medical record review. The study group consisted of our Hospital, between2010and2013. The admitted children were the patients who were diagnosised with heart or lung function failure and accepted ECMO support.SPSS (SPSS for Windows, version20.0, IBM-SPSS, Chicago, IL, USA) was used for statistical analysis. Continuous variables were presented as means and SD and compared with the rate of occurrence or the composition ratio of the chi square. Values of P<0.05were considered to be significant.Results:1.Clinical Situation and Prognosis12cases of children with ECMO assisted support time was81.2±46.5h, the shortest time was12h and the longest time was173h, ICU stay time was10.9±6.4d. There were7cases that successful weaned off ECMO, the probability was58.3%,5cases survived at last, the survival rate was41.6%.5cases can not wean off ECMO and7cases death at last.2. ECMO support application indications and contraindicationsRespiratory support indication:This group of children according to the oxygenation index(OI) and pH value to evaluate whether has the respiratory support indication.4cases of respiratory support, OI was117,40,100and33,3cases were under NO inhalation; pH value of all cases was less than7.25, the body’s oxygen supply and consumption was imbalance caused by hypoxia, resulting in internal environment disturbance of acid-base balance of body.Circulatory support indications:8cases were circulatory support,5cases of these children, ECMO was established to support cardiopulmonary resuscitation. And2cases, ECMO support was put on for weaned off CPB failure after cardiac surgery.1cases are replaced cardiopulmonary bypass during surgery. Contraindications:The irreversible injury of cardiopulmonary function is the contraindications of ECMO application. The pulmonary function evaluation was according to the chest X ray, lung CT scan and ventilator parameters before the ECMO support. The assessment of cardiac function was based on cardiac arrest duration and heart malformation correction. Evaluation of nerve function was based on bedside cranial ultrasound examination, whether intracranial, hydrocephalus etc. Finally, if children were found necrotizing enterocolitis, which would be the absolute contraindications of ECMO support.3. The mode and establishment of ECMOAll children were treated with V-A model ECMO both respiratory and circulatory support. On6cases, with right atrial and ascending aortic cannulation to establish ECMO, accounting for50%. On4cases, with right internal jugular vein and right common carotid artery cannulation to establish ECMO, accounted for33.3%. on2cases, right femoral artery and femoral vein cannulation was procedured to establish ECMO, accounted for16.7%.4. Effect of ECMO on the vital signs and blood gas analysisBefore the ECMO support (T1), after24hours (T2) and48hours (T3), on these three time points, mean arterial pressure(MAP), heart rate and blood gas analysis result were recorded and analyzed by one way ANOVA, results suggest that the MAP, pH value, BE and Lac levels at different time points were significantly different (p<0.05).MAP, pH value, BE and Lac further multiple comparisons can be find:MAP was significantly difference between T1and T2, T3(p<0.05), but no significantly difference between T2and T3(p=0.75). pH was significantly difference between Tl and T2, T3(p<0.05), but no significantly difference between T2and T3(p=0.99). BE was significantly difference between T1and T2, T3(p<0.05), but no significantly difference between T2and T3(p=0.99). Between T1a nd T2, T2and T3, Lac was no significantly difference(p=0.54, p=0.36), but there was significantly difference between T1and T3.(p<0.05).Compared with pre-ECMO support, MAP was obviously increased and blood gas analysis revealed that pH is also higher, BE values tended to be normal, the lactate level is declining. ECMO can well improve the perfusion, internal environment acidosis improved after ECMO support.5. The complication and treatment during ECMOThe complications during ECMO supports can be divided into two categories: mechanical complications and systemic complicationsMechanical complication and treatment:Plasma leakage of the oxygenator were found in5cases during ECMO support period, the incidence was41.7%. When plasma leakage of oxygentor was appeared, only thing we can do was to replace oxygenator. The venous cannula in1cases was blockage, Maybe the cannulation position is not appropriate to discount, the incidence was8.3%.Systemic complication and treatment:In1cases (case10), Rright lower limb ischemic necrosis of toes was appeared, the incidence was8.3%. in5cases, bleeding of operation incision oozing was appeared, the incidence was41.7%, after transfusion of platelets and fresh frozen plasma, ACT was maintained at between140to160seconds, can control the operation incision hemorrhage.1cases had intracranial hemorrhage, incidence was8.3%, the ventricle drainage was given, there were5cases appeared with oliguria, creatinine and urea nitrogen increased, acute renal injury(AKI) were diagnosised, The incidence of AKI was41.7%, all the AKI children were treated with CRRT.6. Wean off and termination of ECMO Before wean off ECMO, bedside chest X ray and cardiac ultrasound were done for evaluation cardiac function recovery in all the children.7cases were successfully weaned off ECMO, the success rate of weaning was58.3%.5cases were failed to wean off ECMO, including3cases were cardiopulmonary function can not be restored, and with the parents consent, ECMO team decided to terminated ECMO.7. Comparision between the successful and failed wean off ECMO groups7cases were successfully weaned off ECMO, weaning rate was58.3%.5cases were failed to wean off ECMO.4cases with respiratory support,2cases were successful weaned off ECMO, but2cases of these children with01>100before ECMO were failed to survive, the only survivors in respiratory support group OI is33pre-ECMO. High values of01may be a risk factor for poor prognosis.Compared with children who were failed to wean off ECMO, successfully weaned off group after24hours ECMO support, the lactic acid level decreased significantly(p<0.05). And the significantly lower incidence of AKI in successful group, compared with the failed ECMO group. Change trend of lactate and AKI incidence could be the related factors of ECMO weaned of,but still needed more clinical data to prove these two points.8. Application of ECPR on cardiopulmonary arrest childrenAmong5cases with ECPR,3cases were successfully weaned off ECMO,1cases (case5) was for the operation incision infection and pulmonary hemorrhage after withdrawal of ECMO for1months.2cases survived (6cases6, cases8).2cases died (cases7, cases11),1case was diagnosis of NEC and terminated of ECMO, another case was weaned off ECMO under the patients’termination decision after26hours on ECMO. Active termination of ECMO program is as follows:firstly, a discussion of the ECMO team, determine whether the cardiopulmonary function can be restored or not, decision to terminate the ECMO support were made after a unified opinion got by the ECMO team, and with the families consent, that the ECMO support will be terminated for ECPR case.9. Treatment of AKI during ECMO support periodAmong12cases, there were5cases diagnosis with AKI during ECMO support period, the incidence of AKI approximately41.7%, and4cases were died of these5patients. And there were3cases died in7cases without AKI during ECMO support period. CRRT system of hemofiltration was selected for the treatment of AKI during ECMO, and the CRRT system was parallel connected with ECMO circuit. The blood inlet of CRRT system is connected to circuit between the pump and the oxygenator, blood returning was connected to the circuit before pump. This way of CRRT on ECMO patients works wll on our clinical practice, the connecting method can guarantee the normal operation of CRRT system, the pressure monitoring points can be guaranteed in the normal range. CRRT treatment in this way can effectively maintain the body fluid balance, effective removal of creatinine and urea nitrogen and other metabolites.Conclusions:1.ECMO can provide effective respiratory and circulatory support for heart failure patients. Today, many other respiratory treatment in respiratory failure children can help to avoid ECMO support, but also delay the those who do need ECMO support. How to distinguish the patients who really need ECMO support from children with respiratory failure is the research direction of clinical workers in PCCM.2.ECPR is the effective means to rescue patients with cardiopulmonary arrest who can not rescue by conventional CPR, it can win the window time for cure the primary disease that lead to cardiac arrest, and have a very important significance in the treatment of pediatric cardiac arrest in children. A practical team of ECPR and a set of ECPR rapid response mechanism, with timely and effective cardiopulmonary resuscitation and accurate assessment of the patients’heart, lungs and nervous system function, can improve the prognosis of cardiac arrest patients. Compared with the pre ECPR serum lactic acid level, dynamic changes in the effective circulatory support after the lactic acid level may be prognostic index for mortality.3.On the critical children with ECMO support, ECMO related complications is the mainly factor affecting the prognosis of the patients. Mechanical complications include plasma leakage of oxygenator and ECMO circuit blockage, generally can only be solved by replacing the ECMO system. Hemorrhage is the most common complications of the system. adjust the amount of heparin, maintain a short ACT time, transfusion of platelets and fresh frozen plasma, most bleeding can be effectively controlled. AKI is the most serious complication of pediatric ECMO support period, Connecting CRRT system with ECMO system in parallel, can guarantee the controllable blood flow and ultrafiltration velocity during CRRT, it can effective maintain volume and fluid balance. To achieve control the flow velocity and ultrafiltration speed accurately was especially significant for low body weight infants on ECMO. This method has not been reported in literature in China and abroad. PART II Effect of ECMO on Annexin A1expression in Peripheral blood mononuclear cellsObjective:ECMO associated systemic inflammatory response syndrome has a close relationship with the body complications. With the beginning hours of the ECMO, systemic inflammatory response syndrome becomes stronger. The clinical manifestations,caused by systemic inflammatory response syndrome, are hypotension, decreased urine output, decreased lung compliance, capillary leakage of systemic edema and damage of liver function which will last for several days and impact the prognosis of the original disease. The aims of the study are as follows.(1)To investigate the involved proteomic profiling of PBMC in the ECMO inflammatory reaction.(2)To examine the effect of ECMO on Annexin Al expression in peripheral blood mononuclear cells (PBMCs) before and after ECMO.Methods:In this study12patients(9males,3females;age:1days to7years old; weight8±6. lkg received ECMO support. PBMCs of peripheral blood(3-5ml) was collected by density gradient centrifugation before and24h after ECMO. The lysis protein extraction was qualificated by2D-QUANT.The images were acquired by UMAX PowerLook1100and then analyzed by PDQuest7.1.0. Mass spectrometry was followed to identify candidate proteins with1.5folds difference after ECMO which were validated by western blot. The data are expressed as x+-s, analyzed by one-way ANOVO test with SPSS13.0software.P<0.05indicates significant difference.Results:l.The average support time of ECMO in12cases was81.2±46.5h.7cases (58.3%) were successfully weaned off ECMO,41.7%(5cases) survived,7cases died, the mortality rate was58.3%.2.Peripheral blood collected at two time points were subjected to two-dimensional electrophoresis and a total of12differentially expressed proteins had been identified. Compared to before ECMO(T1),5proteins (Complement C3precursor, Prostacyclin synthase, Glutathione peroxidase1, Complement component1Q subcomponent-binding protein, Annexin A1) increased after ECMO (T2). However, the remaining7proteins (Protein S100-A9, Actin cytoplasmic1, ATP synthase subunit alpha, mitochondrial precursor, Hemoglobin subunit alpha, Apolipoprotein C-III precursor, Elongation factor1-beta) decreased.3.Considering Annexin A1is an important inflammation regulatory protein, playing a critical role in the production of inflammation, in this study we choose Annexin Al as the subject. Western blot assay shows that Annexin Al expression began to increase after ECMO, and increased significantly24h after CPB (P=0.000). This indicates ECMO can induce the expression of ECMO.Conclusions:1.ECMO support process, the systemic inflammatory reactions mainly originate from existed inflammation before ECMO and contact proinflammatory reactions between the ECMO pipeline and blood.2.The complicated inflammation responses resulted in a series of outcomes. Mononuclear cells are both effective cells of inflammation and regulatory cells, playing an important role in the associated inflammation of ECMO.3. We initially shows the molecular mechanism of mononuclear cell in the inflammation response. However, the activated mechanism of these proteins including Annexin Al and signaling pathways involved are still unclear, and more studies are required.