A Patient Similarity Network (CHDmap) to Predict Outcomes After Congenital Heart Surgery: Development and Validation Study.

Background: Although evidence-based medicine proposes personalized care that considers the best evidence, it still fails to address personal treatment in many real clinical scenarios where the complexity of the situation makes none of the available evidence applicable. "Medicine-based evidence" (MBE), in which big data and machine learning techniques are embraced to derive treatment responses from appropriately matched patients in real-world clinical practice, was proposed. However, many challenges remain in translating this conceptual framework into practice. Objective: This study aimed to technically translate the MBE conceptual framework into practice and evaluate its performance in providing general decision support services for outcomes after congenital heart disease (CHD) surgery. Methods: Data from 4774 CHD surgeries were collected. A total of 66 indicators and all diagnoses were extracted from each echocardiographic report using natural language processing technology. Combined with some basic clinical and surgical information, the distances between each patient were measured by a series of calculation formulas. Inspired by structure-mapping theory, the fusion of distances between different dimensions can be modulated by clinical experts. In addition to supporting direct analogical reasoning, a machine learning model can be constructed based on similar patients to provide personalized prediction. A user-operable patient similarity network (PSN) of CHD called CHDmap was proposed and developed to provide general decision support services based on the MBE approach. Results: Using 256 CHD cases, CHDmap was evaluated on 2 different types of postoperative prognostic prediction tasks: a binary classification task to predict postoperative complications and a multiple classification task to predict mechanical ventilation duration. A simple poll of the k-most similar patients provided by the PSN can achieve better prediction results than the average performance of 3 clinicians. Constructing logistic regression models for prediction using similar patients obtained from the PSN can further improve the performance of the 2 tasks (best area under the receiver operating characteristic curve=0.810 and 0.926, respectively). With the support of CHDmap, clinicians substantially improved their predictive capabilities. Conclusions: Without individual optimization, CHDmap demonstrates competitive performance compared to clinical experts. In addition, CHDmap has the advantage of enabling clinicians to use their superior cognitive abilities in conjunction with it to make decisions that are sometimes even superior to those made using artificial intelligence models. The MBE approach can be embraced in clinical practice, and its full potential can be realized.

Use of extracorporeal membrane oxygenation in children with burn injury: Case report and literature review.

RATIONALE: Burns are one of the most debilitating injuries in the world and one of the major causes of accidental disability and death among children. Severe burns can result in irreversible brain damage, placing patients at high risk of brain failure and high mortality. Therefore, timely diagnosis and treatment of burn encephalopathy are crucial for improving prognosis. In recent years, extracorporeal membrane oxygenation (ECMO) has been increasingly used to improve the prognosis of patients with burns. Here, we report a case of ECMO treatment in a child with burns and review the relevant literature. PATIENT CONCERNS: A 7-year-old boy with a modified Baux score of 24 presented with asphyxia, loss of consciousness, refractory hypoxemia, and malignant arrhythmia after smoke inhalation for 1 day. Fiberoptic bronchoscopy revealed a large amount of black carbon-like substances aspirated from the trachea. DIAGNOSES: Considering that the boy inhaled a large amount of smoke, the clinical manifestation was unclear consciousness, laboratory examination revealed continuous low blood oxygen saturation, and bronchoscopy revealed a large amount of black carbon-like substances in the trachea, thereby leading to the diagnosis of asphyxia, inhalation pneumonia, burn encephalopathy, multiple organ dysfunction syndrome, and malignant arrhythmia. In addition, pulmonary edema and carbon monoxide poisoning are caused by chemical agents, gas fumes, and vapors. INTERVENTIONS: The boy's blood oxygen saturation and blood circulation remained unstable despite various ventilation methods and medications, thus we decided to use ECMO. After 8 days of ECMO support, the patient was successfully weaned from the machine. OUTCOMES: Under the application of ECMO, the respiratory and circulatory systems significantly improved. Nevertheless, due to the progressive brain injury caused by burns and the poor prognosis, the parents ceased all treatment and the boy passed away. LESSONS: This case report demonstrates that brain edema and herniation can arise as phenotypes of burn encephalopathy, which is a challenge to treat in children. Children with confirmed or suspected burn encephalopathy should undergo diagnostic tests completed as soon as possible to confirm the diagnosis. After receiving ECMO treatment, the respiratory and circulatory systems of the burn victims reported significantly improved. Hence, ECMO is a viable alternative for supporting patients with burns.

Mechanosensitive channel MscL induces non-apoptotic cell death and its suppression of tumor growth by ultrasound.

Mechanosensitive channel of large conductance (MscL) is the most thoroughly studied mechanosensitive channel in prokaryotes. Owing to its small molecular weight, clear mechanical gating mechanism, and nanopore forming ability upon opening, accumulating studies are implemented in regulating cell function by activating mechanosensitive channel of large conductance in mammalian cells. This study aimed to investigate the potentials of mechanosensitive channel of large conductance as a nanomedicine and a mechano-inducer in non-small cell lung cancer (NSCLC) A549 cells from the view of molecular pathways and acoustics. The stable cytoplasmic vacuolization model about NSCLC A549 cells was established via the targeted expression of modified mechanosensitive channel of large conductance channels in different subcellular organelles. Subsequent morphological changes in cellular component and expression levels of cell death markers are analyzed by confocal imaging and western blots. The permeability of mitochondrial inner membrane (MIM) exhibited a vital role in cytoplasmic vacuolization formation. Furthermore, mechanosensitive channel of large conductance channel can be activated by low intensity focused ultrasound (LIFU) in A549 cells, and the suppression of A549 tumors in vivo was achieved by LIFU with sound pressure as low as 0.053 MPa. These findings provide insights into the mechanisms underlying non-apoptotic cell death, and validate the nanochannel-based non-invasive ultrasonic strategy for cancer therapy.

A time-aware attention model for prediction of acute kidney injury after pediatric cardiac surgery.

OBJECTIVE: Acute kidney injury (AKI) is a common complication after pediatric cardiac surgery, and the early detection of AKI may allow for timely preventive or therapeutic measures. However, current AKI prediction researches pay less attention to time information among time-series clinical data and model building strategies that meet complex clinical application scenario. This study aims to develop and validate a model for predicting postoperative AKI that operates sequentially over individual time-series clinical data. MATERIALS AND METHODS: A retrospective cohort of 3386 pediatric patients extracted from PIC database was used for training, calibrating, and testing purposes. A time-aware deep learning model was developed and evaluated from 3 clinical perspectives that use different data collection windows and prediction windows to answer different AKI prediction questions encountered in clinical practice. We compared our model with existing state-of-the-art models from 3 clinical perspectives using the area under the receiver operating characteristic curve (ROC AUC) and the area under the precision-recall curve (PR AUC). RESULTS: Our proposed model significantly outperformed the existing state-of-the-art models with an improved average performance for any AKI prediction from the 3 evaluation perspectives. This model predicted 91% of all AKI episodes using data collected at 24 h after surgery, resulting in a ROC AUC of 0.908 and a PR AUC of 0.898. On average, our model predicted 83% of all AKI episodes that occurred within the different time windows in the 3 evaluation perspectives. The calibration performance of the proposed model was substantially higher than the existing state-of-the-art models. CONCLUSIONS: This study showed that a deep learning model can accurately predict postoperative AKI using perioperative time-series data. It has the potential to be integrated into real-time clinical decision support systems to support postoperative care planning.

Induction of apoptosis and ferroptosis by a tumor suppressing magnetic field through ROS-mediated DNA damage.

Magnetic field (MF) is being used in antitumor treatment; however, the underlying biological mechanisms remain unclear. In this study, the potency and mechanism of a previously published tumor suppressing MF exposure protocol were further investigated. This protocol, characterized as a 50 Hz electromagnetic field modulated by static MF with time-average intensity of 5.1 mT, when applied for 2 h daily for over 3 consecutive days, selectively inhibited the growth of a broad spectrum of tumor cell lines including lung cancer, gastric cancer, pancreatic cancer and nephroblastoma. The level of intracellular reactive oxygen species (ROS) increased shortly after field exposure and persisted. Subsequently, pronounced DNA damage and activation of DNA repair pathways were identified both in vitro and in vivo. Furthermore, use of free radical scavenger alleviated DNA damage and partially reduced cell death. Finally, this field was found to inhibit cell proliferation, and simultaneously induced two types of programmed cell death, apoptosis and ferroptosis. In conclusion, this tumor suppressing MF could determine cell fate through ROS-induced DNA damage, inducing oxidative stress and activation of the DNA damage repair pathways, eventually lead to apoptosis and ferroptosis, as well as inhibition of tumor growth.

Integrin α5 subunit is required for the tumor supportive role of fibroblasts in colorectal adenocarcinoma and serves as a potential stroma prognostic marker.

The tumorigenesis of colorectal cancer (CRC) is a complicated process, involving interactions between cancer cells and the microenvironment. The role of α5 integrin subunit in CRC remains controversial, and previous studies mainly focused on cancer cells. Herein, we report an important role of α5 in stroma fibroblasts in the tumorigenesis of CRC. The expression of α5 was found to be located in colorectal tumor stroma rather than in epithelia cancer cells. Immunofluorescence colocalization and gene correlation analysis confirmed that α5 was mainly expressed in cancer-associated fibroblasts (CAFs). Moreover, experimental evidence showed that α5 expression was required for the tumor-promoting effect of fibroblast cells. In an in vivo xenograft nude mice model, α5 depletion in fibroblasts dramatically suppressed fibroblast-induced tumor growth. In an in vitro cell coculture assay, α5 depletion or knockdown reduced the ability of fibroblasts to promote cancer cell migration and invasion compared with wild-type fibroblasts; moreover, we observed that the expression and assembly of fibronectin were downregulated after α5 depletion or knockdown in fibroblasts. Analysis of the RNA-Seq data of the Cancer Genome Atlas cohort revealed that high expression of ITGA5 (α5 integrin subunit) was correlated with poor overall survival in colorectal adenocarcinoma, which was further confirmed by immunohistochemistry in an independent cohort of 355 patients. Thus, our study identifies α5 integrin subunit as a novel stroma molecular marker for colorectal adenocarcinoma, offers a fresh insight into colorectal adenocarcinoma progression, and shows that α5 expression in stroma fibroblasts underlies its ability to promote the tumorigenesis of colorectal adenocarcinoma.

Tigecycline salvage therapy for critically ill children with multidrug-resistant/extensively drug-resistant infections after surgery.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of salvage therapy of tigecycline in critically ill children with infections caused by multidrug-resistant (MDR)/extensively drug-resistant (XDR) bacteria after surgery. METHODS: A retrospective chart review was performed of critically ill children after surgery who had received tigecycline for ≥3days between June 2012 and May 2016 in the surgical intensive care unit of a tertiary level children's hospital. RESULTS: Of 6442 consecutive children admitted after surgery, a total of 22 were enrolled. They had a median age of 7.5 months (interquartile range (IQR), 6 months to 4 years) and a median weight of 7.3kg (IQR, 5.1-12.5kg). Patients received tigecycline for a median 17days (IQR, 12-20 days). The median intensive care unit stay was 56days (IQR, 38-61 days) and median hospital stay was 78days (IQR, 61-94 days). Tigecycline was prescribed as culture-directed therapy in 91% of patients and as empirical therapy in 9%. Clinical success was reported in 86% of the patients. The all-cause mortality in this cohort was 18%. No serious adverse effects of tigecycline were detected in these patients. CONCLUSIONS: Tigecycline salvage therapy was successful in 86% of critically ill pediatric patients with MDR/XDR infections after surgery, with no severe adverse effects.

High shear stress-induced pulmonary hypertension alleviated by endothelial progenitor cells independent of autophagy.

BACKGROUND: Pulmonary hypertension (PH) is a progressive disease characterized by lung endothelial cell dysfunction and vascular remodeling. Endothelial progenitor cells (EPCs) have been proved to be a potential therapeutic strategy to treat PH. Autophagy has been found to be protective to hypoxia-induced PH. In this study, we applied high shear stress (HSS)-induced PH, and examined whether EPCs confer resistance against HSS-induced PH through autophagy. METHODS: Pulmonary microvascular endothelial cells (PMVECs) were cultured under HSS with pro-inflammatory factors in an artificial capillary system to mimic the PH condition. Levels of p62, a selective autophagy substrate, were quantified by western blotting. Cell viability was determined by trypan blue exclusion test. RESULTS: The p62 level in PMVECs was increased at 4 hours after HSS, peaked at 12 hours and declined at 24 hours. The cell viability gradually decreased. Compared with PMVECs cultured by empty medium, in cells cultured by EPC-conditioned medium (EPC-CM), the cell viability was significantly higher; however, p62 levels were also significantly higher, suggesting inhibition of autophagy by EPC-CM. Adding choloquine to suppress autophagy decreased the cell viability of PMVECs under PH. CONCLUSIONS: EPC-CM could suppress the autophagic activity of PMVECs in HSS-induced PH. However, suppression of autophagy leads to cell death. EPCs could fight against PH through cellular or molecular pathways independent of autophagy. But it is not proved if induction of autophagy could be a potential strategy to treat HSS-induced PH as hypoxia-induced PH.

The role of plasma gelsolin in cardiopulmonary bypass induced acute lung injury in infants and young children: a pilot study.

BACKGROUND: Acute lung injury (ALI) induced by cardiopulmonary bypass (CPB, CPB-ALI) is a common and serious complication after cardiac surgery. And infants and young children are more prone to CPB-ALI. The purpose of this study was to investigate the perioperative changes of plasma gelsolin (pGSN) in patients below 3 years of age with cardiac surgeries and CPB, and determine whether pGSN are associated with the occurrence and severity of CPB-ALI. METHODS: Seventy-seven consecutive patients ≤3 years of age with congenital heart diseases (CHD) performed on open heart surgery with CPB were finally enrolled, and assigned to ALI and non-ALI groups according to the American-European Consensus Criteria. Plasma concentrations of gelsolin and total protein were measured at following 8 time points: before CPB (a), after CPB (b), 2 hours after CPB (c), 6 hours after CPB (d), 12 hours after CPB (e), 24 hours after CPB (f), 48 hours after CPB (g) and 72 hours after CPB (h). RESULTS: Twenty-seven (35.1%) patients developed CPB-ALI in the study, including eleven (14.3%) patients with ARDS. The earliest significant drop of pGSN and normalized pGSN (pGSNN) of ALI group both occurred at 6 hours after CPB (p = 0.04 and p < 0.01), which was much earlier than those of non-ALI group (48 hours, p = 0.03 and 24 hours, p < 0.01); PGSN of ALI group before CPB and 6 hours after CPB were both significantly lower than those of non-ALI group (p < 0.01); PGSNN of ALI group before CPB and 6 hours after CPB were both significantly lower than those of non-ALI group (p < 0.01, p = 0.04); PGSN before CPB was the only independent risk factor predicting the occurrence of CPB-ALI (OR, 1.023; 95% CI, 1.007-1.039; p < 0.01) with an AUC of 0.753 (95% CI, 0.626-0.880); The optimal cutoff value of pGSN before CPB was 264.2 mg/L, with a sensitivity of 58.3% and a specificity 94.7%. And lower pGSN before CPB was significantly associated with the severity of CS-AKI (r = -0.45, p < 0.01). CONCLUSIONS: Patients developing CPB-ALI had lower plasma gelsolin reservoir and a much more amount and rapid consumption of plasma gelsolin early after operation. PGSN before CPB was an early and sensitive predictor of CPB-ALI in infants and young children undergoing cardiac surgery, and was negatively correlated with the severity of CPB-ALI.

Repair of ventricular septal defect with Eisenmenger syndrome after bosentan treatment.

We report a patient with ventricular septal defect (VSD) and Eisenmenger syndrome. The patient was treated with bosentan for 12 weeks, with a decrease in pulmonary vascular resistance index (PRVi) from 18.84 to 9.63 Wood unit (WU) m2 , and underwent successful corrective repair of the VSD after 12 weeks of bosentan therapy.

Plasma sRAGE enables prediction of acute lung injury after cardiac surgery in children.

INTRODUCTION: Acute lung injury (ALI) after cardiac surgery is associated with a high postoperative morbidity and mortality, but few predictors are known for the occurrence of the complication. This study evaluated whether elevated plasma levels of soluble receptor for advanced glycation end products (sRAGE) and S100A12 reflected impaired lung function in infants and young children after cardiac surgery necessitating cardiopulmonary bypass (CPB). METHODS: Consecutive children younger than 3 years after cardiac surgery were prospectively enrolled and assigned to ALI and non-ALI groups, according to the American-European Consensus Criteria. Plasma concentrations of sRAGE and S100A12 were measured at baseline, before, and immediately after CPB, as well as 1 hour, 12 hours, and 24 hours after operation. RESULTS: Fifty-eight patients were enrolled and 16 (27.6%) developed postoperative ALI. Plasma sRAGE and S100A12 levels increased immediately after CPB and remained significantly higher in the ALI group even 24 hour after operation (P < 0.01). In addition, a one-way MANOVA revealed that the overall sRAGE and S100A12 levels were higher in the ALI group than in the non-ALI group immediately after CPB (P < 0.001). The multivariate logistic regression analysis showed that the plasma sRAGE level immediately after CPB was an independent predictor for postoperative ALI (OR, 1.088; 95% CI, 1.011 to 1.171; P = 0.025). Increased sRAGE and S100A12 levels immediately after CPB were significantly correlated with a lower PaO2/FiO2 ratio (P < 0.01) and higher radiographic lung-injury score (P < 0.01), as well as longer mechanical ventilation time (sRAGEN: r = 0.405; P = 0.002; S100A12N: r = 0.322; P = 0.014), longer surgical intensive care unit stay (sRAGEN: r = 0.421; P = 0.001; S100A12N: r = 0.365; P = 0.005) and hospital stay (sRAGEN: r = 0.329; P = 0.012; S100A12N: r = 0.471; P = 0.001). CONCLUSIONS: Elevated sRAGE and S100A12 levels correlate with impaired lung function, and sRAGE is a useful early biomarker of ALI in infants and young children undergoing cardiac surgery.

Increased nitrosoglutathione reductase activity in hypoxic pulmonary hypertension in mice.

Altered S-nitrosothiols (RSNO) signaling is linked to pulmonary hypertension. Recent studies have shown that S-nitrosoglutathione (GSNO) reductase (GSNOR) catalyzes the degradation of GSNO and indirectly regulates the level of RSNO in vivo. Our present study tested the hypothesis that chronic hypoxia causes pulmonary hypertension, in part, by the change of GSNOR activity that contributes to the depletion of RSNO. Male mice were exposed to normobaric hypoxia in a ventilated chamber for 1 to 21 days or normoxia for 21 days. Right ventricular systolic pressure, right ventricle hypertrophy, and the number and media thickness of muscular pulmonary vessels increased significantly after 21 days of hypoxic exposure. Hypoxia induced the overexpression of endothelial nitric oxide synthase and inducible nitric oxide synthase. The mRNA expression of GSNOR decreased on day 1 of hypoxic exposure, but increased significantly on day 7 compared with the normoxic group. The protein expression of GSNOR increased significantly in the lung tissue after 7 days of hypoxic exposure and its enzymatic activities also increased. Both the ratios of glutathione to glutathione disulfide and nitrate to nitrite were significantly lower in the hypoxic groups than in the normoxic controls. The results suggest an increased GSNOR activity interfered with the metabolism of RSNO in mice with hypoxic pulmonary hypertension. An imbalanced of redox status is associated with the pathogenesis of hypoxic pulmonary hypertension.

Extracorporeal membrane oxygenation for the treatment of children with severe hemodynamic alteration in perioperative cardiovascular surgery.

BACKGROUND: This article summarizes the use of extracorporeal membrane oxygenation (ECMO) for the treatment of children with severe hemodynamic alteration in perioperative cardiovascular surgery. METHODS: Four children with congenital heart disease (CHD) (3 boys and 1 girl, aged 6 days to 4 years and weighing 2.8-15 kg) associated with severe heart failure and/or hypoxemia were treated with ECMO cardiopulmonary support in perioperative cardiovascular surgery between July 2007 and July 2008. We retrospectively analyzed the medical records of the 4 children. RESULTS: Of the 4 children, 2 survived and 2 died. The survivors were treated with venoarterial (VA) ECMO due to severe low output syndrome after arterial switch operation. They were weaned successfully from 22-hour and 87-hour ECMO support, and discharged 20 days and 58 days after ECMO explantation, respectively. The other boy treated with venovenous ECMO died of severe hypoxemia and metabolic acidosis. The other girl with VSD, treated with VA ECMO because of failure to wean from cardiopulmonary bypass, died from irreversible heart failure 11 hours after ECMO explantation. The main complications in this series included pulmonary hemorrhage, blood tamponade, surgical site bleeding, hemolysis and hyperbilirubinemia. CONCLUSIONS: ECMO is an effective therapy for patients with severe heart failure in the perioperative cardiovascular surgery. The keys to successful ECMO are selection of indications, time to set up ECMO, and good management of complications during ECMO.

Perioperative risk factors for prolonged mechanical ventilation following cardiac surgery in neonates and young infants.

BACKGROUND: Prolonged mechanical ventilation (PMV) after cardiac surgery in children is associated with a high postoperative morbidity and mortality, as well as increased ICU and hospital resource utilization. Little has been done to identify the predictors of PMV in neonates and young infants. This study was performed to evaluate the perioperative risk factors for PMV in neonates and young infants undergoing cardiac surgery. METHODS: Clinical records of 172 consecutive children aged < or = 3 months were reviewed. PMV was defined as mechanical ventilation (MV) > or = 72 h following operation. After univariate analysis, a stepwise logistic regression analysis was used to evaluate the independent risk factors for PMV following cardiac surgery. The predictive ability of risk factors for PMV was assessed using an area under the receiver operating characteristic (ROC) curve. RESULTS: Sixty-one patients required PMV after cardiac surgery. The median duration of MV was 150 h in PMV patients, while it was 28 h in non-PMV patients. The independent risk factors for PMV were risk adjustment for surgery for congenital heart disease (RACHS)-1 (p = 0.041), nosocomial pneumonia (p = 0.001), low cardiac output syndrome (LCOS) [p = 0.001], postoperative cumulative positive fluid balance (p = 0.032), and extubation failure (EF) [p = 0.027]. The value for the ROC curve was 0.940. CONCLUSIONS: The present results strongly suggest that RACHS-1, nosocomial pneumonia, LCOS, fluid retention postoperatively, and EF are risk factors for PMV in neonates and young infants undergoing reparative surgery for congenital heart disease.

[Extracorporeal membrane oxygenation treatment of a neonate with severe low cardiac output syndrome following open heart surgery].

OBJECTIVE: To summarize the experience of extracorporeal membrane oxygenation (ECMO) to rescue a neonate with severe low cardiac output syndrome following open heart surgery. METHODS: The patient was a male, 2 d, 2.8 kg, G3P2 full-term neonate with gestational age 40 weeks, born by Cesarean-section with Apgar score of 10 at 1 min. He was admitted due to severe dyspnea with oxygen desaturation and heart murmur on the second day after birth. Physical examination showed clear consciousness, cyanosis, dyspnea, RR 70 bpm and a grade II/6 heart murmur. Bp was 56/45 mm Hg (1 mm Hg = 0.133 kPa) and SpO2 around 65%. Blood WBC 13.1 x 10(9)/L, N 46.1%, Hb 238 g/L, Plt 283 x 10(9)/L, CRP < 1 mg/L. Echocardiographic findings: TGA + ASD + PDA with left ventricular ejection fraction (LVEF) of 60%. After supportive care and prostaglandin E1 (5 ng/kg/min) treatment, his condition became stable with SpO2 85 - 90%. On the 6(th) day of life, the baby underwent an arterial switch procedure + ASD closing and PDA ligation. The time of aorta clamp was 72 mins. The cool 4:1 blood cardioplegia was given for 2 times during aortal clamp. Ultrafiltration was used. The internal and external volumes were almost equal and the electrolytes and blood gas and hematocrit (36%) were normal during extracorporeal bypass. Due to a failure (severe low cardiac output) to wean from cardiopulmonary bypass (263 min) with acidosis (lactate 8.8 mmol/L), low blood pressure (< 39/30 mm Hg), increased LAP (> 20 mmHg), bloody phlegm, decreased urine output [< 1 ml/(kg.h)], a V-A ECMO was used for cardio-pulmonary support. ECMO setup: Medtronic pediatric ECMO package (CB2503R1), carmeda membrane oxygenator and centrifugal pump (bio-console 560) were chosen. Direct cannulation of the ascending aorta (Edward FEM008A) and right atrium (TF018090) was performed using techniques that were standard for cardiopulmanory bypass. The ECMO system was primed with 400 ml blood, 5% CaCl(2)1g, 5% sodium bicarbonate 1.5 g, 20% mannitol 2 g, albumin 10 g, and heparin 5 mg. The blood was re-circulated until the temperature was 37 degrees C and blood gases and the electrolytes were in normal range. The patient was weaned from bypass and connected to V-A ECMO. Management of ECMO: the blood flow was set at 150 - 200 ml/kg/min. Venous saturation (SvO2) was maintained at the desired level (75%) by increasing and decreasing extracorporeal blood flow. Systemic blood pressure was maintained at 76/55 - 80/59 mm Hg by adjusting blood volume. Hemoglobin was maintained between 120 - 130 g/L. Platelet count was maintained at > 75,000/mm3 and ACT was maintained at 120 - 190 s. The mechanical ventilation was reduced to lung rest settings (FiO2 35%, RR 10 bpm, PIP 16 cm H(2)O, PEEP 5 cm H2O) to prevent alveolar collapse. Inotropic drug dosages were kept at a low level. RESULTS: The patient was successfully weaned from ECMO following 87 hours treatment. LVEF on day 1, 2 and 3 following ECMO were 20%, 34% and 43% respectively. The circulation was stable after weaning from ECMO with Bp 75/55 mm Hg, HR 160 bpm and LAP 11 mm Hg under inotropic drug suppor with epinephrine [(0.2 microg/(kg.min)], dopamine [(8 microg/(kg.min)], milrinone [(0.56 microg/(kg.min)]. The blood gases after 1 h off-ECMO showed: pH 7.39, PaO2 104 mm Hg, PaCO2 45 mm Hg, lactate 3.8 mmol/L, Hct 35%, K(+) 3.8 mmol/L, Ca(++) 1.31 mmol/L. The serum lactate was normal after 24 h off-ECMO. On day 22 off-ECMO, the baby was successfully extubated and weaned from conventional ventilator. On day 58, the patient was discharged. Serial ultrasound imaging studies revealed no cerebral infarction or intracranial hemorrhage during and after ECMO. At the time of hospital discharge, the patient demonstrated clear consciousness with good activity, normal function of heart, lung, liver and kidney. However, more subtle morbidities, such as behavior problems, learning disabilities should be observed ria long term follow-up. The main ECMO complications were pulmonary hemorrhage, bleeding on the sternal wound, tamponade, hemolysis and hyperbilirubinemia. CONCLUSION: ECMO is an effective option of cardio-pulmonary support for neonate with low cardiac output syndrome following open heart surgery.

Epidemiology of nosocomial pneumonia in infants after cardiac surgery.

BACKGROUND: The pattern of nosocomial pneumonia (NP) in infants in a pediatric surgical ICU after cardiac surgery may differ from that seen in adult ICUs. STUDY OBJECTIVES: The primary aim of this study was to describe the epidemiology of NP in infants after cardiac surgery and, secondarily, to describe the changes of the distribution and antibiotic resistance of the pathogen during the last 3 years. METHODS: Data were collected between June 1999 and June 2002 from 311 consecutive infants who underwent open-heart surgery in our hospital. We retrospectively analyzed the distribution and antibiotic resistance pattern of all the pathogenic microbial isolates cultured from lower respiratory tract aspirations. RESULTS: Of 311 infants, 67 patients (21.5%) acquired NP after cardiac surgery. The incidence of NP was more frequently associated with complex congenital heart defect (CHD) compared to simple CHD (43% vs 15.9%, chi(2) = 22.47, p < 0.0001). The proportion of late-onset NP was higher in patients with complex CHD (chi(2) = 6.02, p = 0.014). A total of 79 pathogenic microbial strains were isolated. Gram-negative bacilli (GNB) were the most frequent isolates (68 isolates, 86.1%), followed by fungi (6 isolates, 7.6%) and Gram-positive cocci (5 isolates, 6.3%). The main GNB were Acinetobacter baumanii (11 isolates, 13.9%), Pseudomonas aeruginosa (10 isolates, 12.7%); other commonly seen GNB were Flavobacterium meningosepticum (7 isolates, 8.9%), Klebsiella pneumoniae (7 isolates, 8.9%), Escherichia coli (6 isolates, 7.6%), and Xanthomonas maltophilia (5 isolates, 6.2%). The most commonly seen Gram-positive cocci were Staphylococcus aureus (2 isolates, 2.5%) and Staphylococcus epidermidis (2 isolates, 2.5%). The frequent fungi were Candida albicans (5 isolates, 6.3%). Most GNB were sensitive to cefoperazone-sulbactum, piperacillin-tazobactam, imipenem, ciprofloxacin, amikacin. The bacteria producing extended spectrum beta-lactamases were mainly from K pneumoniae and E coli; the susceptibility of ESBL-producing strains to imipenem was 100%. There were one case of methicillin-resistant S aureus (MRSA) and 1 case of methicillin-resistant S epidermidis; their susceptibility to vancomycin, gentamycin, and ciprofloxacin were 100%. From 1999 to 2002 in infants with NP after open-heart surgery, there was a trend of increasing frequency of multiresistant GNB such as A baumanii, P aeruginosa, and K pneumoniae. However, no remarkable changes of distribution were found in Gram-positive cocci and fungi in the 3-year period. Early onset episodes of NP were frequently caused by Haemophilus influenzae, methicillin-sensitive S aureus, and other susceptible Enterobacteriaceae. Conversely, in patients who acquired late-onset NP, P aeruginosa, A baumannii, other multiresistant GNB, MRSA, and fungi were the predominant organisms. CONCLUSIONS: The pattern of pathogens and their antibiotic-resistance patterns in NP in infants after cardiac surgery had not shown an increasing prevalence of Gram-positive pathogens as reported by several adult ICUs. GNB still remained the most common pathogens during the last 3 years in our hospital. There was a trend of increasing antibiotic resistance in these isolates.

[The risk factors of failed extubation after cardiac surgery in infants].

OBJECTIVE: To investigate the risk factors of failed extubation (FE) after cardiac surgery in infants. METHODS: 227 infants (< 1 year of age) who underwent congenital heart surgery in the period between January 2001 and December 2002 were included in this study. Logistic regression analysis was used to assess the risk factors of failed extubation. Odds Ratio was used to suppose the degree of relationship between FE and risk factors. RESULTS: Out of the 227 infants undergoing congenital heart operations, 30 (13.22%) cases failed at the extubation. Risk factors for failed extubation included postoperative duration of ventilation (EOR = 12.0; 95% CI = 4.04 - 35.71; P = 0.000 9), postoperative pneumonia (EOR = 5.33; 95% CI = 1.81 - 15.68; P = 0.002) and preoperative pulmonary hypertension (EOR = 2.80; 95% CI = 1.21 - 10.45; P = 0.041). Postoperative pneumonia and preoperative pulmonary hypertension were the 2 independent risk factors for failed extubation (P < 0.05). CONCLUSIONS: Postoperative pneumonia and preoperative pulmonary hypertension are major risk factors for failed extubation after congenital heart surgery in infants. To prevent and to treat postoperative pneumonia and pulmonary hypertensive crises will be beneficial to the successful extubation.