The influence of liver transplantation on the interplay between gut microbiome and bile acid homeostasis in children with biliary atresia.

BACKGROUND: Biliary atresia (BA) causes neonatal cholestasis and rapidly progresses into cirrhosis if left untreated. Kasai portoenterostomy may delay cirrhosis. BA remains among the most common indications for liver transplantation (LT) during childhood. Liver function and gut microbiome are interconnected. Disturbed liver function and enterohepatic signaling influence microbial diversity. We, herein, investigate the impact of LT and reestablishment of bile flow on gut microbiome-bile acid homeostasis in children with BA before (pre, n = 10), 3 months (post3m, n = 12), 12 months (post12m, n = 9), and more than 24 months (post24 + m, n = 12) after LT. METHODS: We analyzed the intestinal microbiome of BA patients before and after LT by 16S-rRNA-sequencing and bioinformatics analyses, and serum primary and secondary bile acid levels. RESULTS: The gut microbiome in BA patients exhibits a markedly reduced alpha diversity in pre (p = 0.015) and post3m group (p = 0.044), and approximated healthy control groups at later timepoints post12m (p = 1.0) and post24 + m (p = 0.74). Beta diversity analysis showed overall community structure similarities of pre and post3m (p = 0.675), but both differed from the post24 + m (p < 0.001). Longitudinal analysis of the composition of the gut microbiome revealed the Klebsiella genus to show increased abundance in the post24 + m group compared with an age-matched control (p = 0.029). Secondary bile acid production increased 2+ years after LT (p = 0.03). Multivariable associations of microbial communities and clinical metadata reveal several significant associations of microbial genera with tacrolimus and mycophenolate mofetil-based immunosuppressive regimens. CONCLUSIONS: In children with BA, the gut microbiome shows strongly reduced diversity before and shortly after LT, and approximates healthy controls at later timepoints. Changes in diversity correlate with altered secondary bile acid synthesis at 2+ years and with the selection of different immunosuppressants.

Internal Ileal Diversion as Treatment for Progressive Familial Intrahepatic Cholestasis Type 1-Associated Graft Inflammation and Steatosis after Liver Transplantation.

BACKGROUND: Progressive Familial Intrahepatic cholestasis type I (PFIC1) is a rare congenital hepatopathy causing cholestasis with progressive liver disease. Surgical interruption of the enterohepatic circulation, e.g., surgical biliary diversion (SBD) can slow down development of liver cirrhosis. Eventually, end stage liver disease necessitates liver transplantation (LT). PFIC1 patients might develop diarrhea, graft steatosis and inflammation after LT. SBD after LT was shown to be effective in the alleviation of liver steatosis and graft injury. CASE REPORT: Three PFIC1 patients received LT at the ages of two, two and a half and five years. Shortly after LT diarrhea and graft steatosis was recognized, SBD to the terminal ileum was opted to prevent risk for ascending cholangitis. After SBD, inflammation and steatosis was found to be reduced to resolved, as seen by liver biochemistry and ultrasounds. Diarrhea was reported unchanged. CONCLUSION: We present three PFIC1 cases for whom SBD to the terminal ileum successfully helped to resolve graft inflammation and steatosis.

New Therapeutic Approach in an Infant With Systemic Myofibromatosis and Intestinal Hemorrhage.

We report the case of an infant with multicentric myofibromatosis affecting the gastric and intestinal mucosa, leading to continuous intestinal hemorrhage and iron deficiency. Conventional vinblastine and methotrexate combination treatment was administered for 4 months, but persistent intestinal blood loss required repeated blood transfusions. Because of insufficient tumor response to treatment, we opted for the experimental combination of rapamycin and dasatinib. Six weeks after the start of this therapy, hemoglobin levels stabilized without transfusions, and no fecal blood loss was detected. In addition, a follow-up magnetic resonance imaging excluded tumor progression. We here show the effectiveness of an experimental therapy with rapamycin and dasatinib in a child with multicentric myofibromatosis after the failure of conventional therapy with vinblastine and methotrexate.

Influence of early biliary complications on survival rates after pediatric liver transplantation-A positive outlook.

BACKGROUND: Early biliary complications (EBC) constitute a burden after pediatric liver transplantation frequently requiring immediate therapy. We aimed to assess the impact of EBC on short- and long-term patient and graft survival as well as post-transplant morbidity. METHODS: We analyzed 121 pediatric liver transplantations performed between 1984 and 2019 at the Medical University of Innsbruck for the occurrence of early (<90 days) biliary complications and investigated the influence of EBC on patient and graft survival. RESULTS: Early biliary complications occurred in 30 (24.8%) out of the 121 pediatric liver transplant recipients. Patient survival at 15 years (89.2% vs. 84.2%, p = .65) and all-cause (82.5% vs. 74.0%) and death-censored graft survival (82.5% vs. 75.1%, p = .71) at 10 years were similar between the EBC and the non-EBC group. The EBC group had a significantly longer ICU (25 vs. 16 days, p < .001) and initial hospital stay (64 vs. 42 days, p = .002). Livers of patients with EBC were characterized by multiple bile ducts (33.3% vs. 13.2%, p = .027), and patients with EBC had a higher risk to develop late biliary complications (OR 2.821 [95% CI 1.049-7.587], p = .044) and bowel obstruction/perforation (OR 4.388 [95% CI 1.503-12.812], p = .007). CONCLUSION: Early biliary complications after pediatric liver transplantation is frequent. The occurrence of EBC significantly increased post-transplant morbidity without affecting mortality. Multiple bile ducts were the only risk factor for the development of EBC in our cohort.

Method comparison of HPLC-ninhydrin-photometry and UHPLC-PITC-tandem mass spectrometry for serum amino acid analyses in patients with complex congenital heart disease and controls.

INTRODUCTION: Metabolomics studies are not routine when quantifying amino acids (AA) in congenital heart disease (CHD). OBJECTIVES: Comparative analysis of 24 AA in serum by traditional high-performance liquid chromatography (HPLC) based on ion exchange and ninhydrin derivatisation followed by photometry (PM) with ultra-high-performance liquid chromatography and phenylisothiocyanate derivatisation followed by tandem mass spectrometry (TMS); interpretation of findings in CHD patients and controls. METHODS: PM: Sample analysis as above (total run time, ~ 119 min). TMS: Sample analysis by AbsoluteIDQ® p180 kit assay (BIOCRATES Life Sciences AG, Innsbruck, Austria), which employs PITC derivatisation; separation of analytes on a Waters Acquity UHPLC BEH18 C18 reversed-phase column, using water and acetonitrile with 0.1% formic acid as the mobile phases; and quantification on a Triple-Stage Quadrupole tandem mass spectrometer (Thermo Fisher Scientific, Waltham, MA) with electrospray ionisation in the presence of internal standards (total run time, ~ 8 min). Calculation of coefficients of variation (CV) (for precision), intra- and interday accuracies, limits of detection (LOD), limits of quantification (LOQ), and mean concentrations. RESULTS: Both methods yielded acceptable results with regard to precision (CV < 10% PM, < 20% TMS), accuracies (< 10% PM, < 34% TMS), LOD, and LOQ. For both Fontan patients and controls AA concentrations differed significantly between methods, but patterns yielded overall were parallel. CONCLUSION: Serum AA concentrations differ with analytical methods but both methods are suitable for AA pattern recognition. TMS is a time-saving alternative to traditional PM under physiological conditions as well as in patients with CHD. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier NCT03886935, date of registration March 27th, 2019 (retrospectively registered).

Stereotactic radiofrequency ablation of a variety of liver masses in children.

BACKGROUND AND AIMS: Surgical resection is currently the cornerstone of liver tumor treatment in children. In adults radiofrequency ablation (RFA) is an established minimally invasive treatment option for small focal liver tumors. Multiprobe stereotactic RFA (SRFA) with intraoperative image fusion to confirm ablation margins allows treatment for large lesions. We describe our experience with SRFA in children with liver masses. METHODS: SRFA was performed in 10 patients with a median age of 14 years (range 0.5-17.0 years) suffering from liver adenoma (n = 3), hepatocellular carcinoma (n = 1), hepatoblastoma (n = 2), myofibroblastic tumor (n = 1), hepatic metastases of extrahepatic tumors (n = 2) and infiltrative hepatic cysts associated with alveolar echinococcosis (n = 1). Overall, 15 lesions with a mean lesion size of 2.6 cm (range 0.7-9.5 cm) were treated in 11 sessions. RESULTS: The technical success rate was 100%, as was the survival rate. No transient adverse effects higher than grade II (Clavien and Dindo) were encountered after interventions. The median hospital stay was 5 d (range 2-33 d). In two patients who subsequently underwent transplant hepatectomy complete ablation was histologically confirmed. Follow-up imaging studies (median 55 months, range 18-129 months) revealed no local or distant recurrence of disease in any patient. CONCLUSIONS: SRFA is an effective minimal-invasive treatment option in pediatric patients with liver tumors of different etiologies.

Targeted metabolomic analysis of serum amino acids in the adult Fontan patient with a dominant left ventricle.

Growing interest lies in the assessment of the metabolic status of patients with a univentricular circulation after Fontan operation, especially in changes of amino acid metabolism. Using targeted metabolomic examinations, we investigated amino acid metabolism in a homogeneous adult Fontan-patient group with a dominant left ventricle, seeking biomarker patterns that might permit better understanding of Fontan pathophysiology and early detection of subtle ventricular or circulatory dysfunction. We compared serum amino acid levels (42 analytes; AbsoluteIDQ p180 kit, Biocrates Life Sciences, Innsbruck, Austria) in 20 adult Fontan patients with a dominant left ventricle and those in age- and sex-matched biventricular controls. Serum concentrations of asymmetric dimethylarginine, methionine sulfoxide, glutamic acid, and trans-4-hydroxyproline and the methionine sulfoxide/methionine ratio (Met-SO/Met) were significantly higher and serum concentrations of asparagine, histidine, taurine, and threonine were significantly lower in patients than in controls. Met-SO/Met values exhibited a significant negative correlation with oxygen uptake during exercise. The alterations in amino acid metabolome that we found in Fontan patients suggest links between Fontan pathophysiology, altered cell energy metabolism, oxidative stress, and endothelial dysfunction like those found in biventricular patients with congestive heart failure. Studies of extended amino acid metabolism may allow better understanding of Fontan pathophysiology that will permit early detection of subtle ventricular or circulatory dysfunction in Fontan patients.

Targeted metabolomic analysis of serum phospholipid and acylcarnitine in the adult Fontan patient with a dominant left ventricle.

BACKGROUND: Patients with a Fontan circulation have altered cholesterol and lipoprotein values. We analysed small organic molecules in extended phopsholipid and acylcarnitine metabolic pathways ('metabolomes') in adult Fontan patients with a dominant left ventricle, seeking differences between profiles in baseline and Fontan circulations. METHODS: In an observational matched cross-sectional study, we compared phosphatidylcholine (PC), sphingomyelin (SM), and acylcarnitine metabolomes (105 analytes; AbsoluteIDQ® p180 kit (Biocrates Life Sciences AG, Innsbruck, Austria) in 20 adult Fontan patients having a dominant left ventricle with those in 20 age- and sex-matched healthy controls. RESULTS: Serum levels of total PC (q-value 0.01), total SM (q-value 0.0002) were significantly lower, and total acylcarnitines (q-value 0.02) were significantly higher in patients than in controls. After normalisation of data, serum levels of 12 PC and 1 SM Fontan patients were significantly lower (q-values <0.05), and concentrations of 3 acylcarnitines were significantly higher than those in controls (q-values <0.05). CONCLUSION: Metabolomic profiling can use small specimens to identify biomarker patterns that track derangement in multiple metabolic pathways. The striking alterations in the phospholipid and acylcarnitine metabolome that we found in Fontan patients may reflect altered cell signalling and metabolism as found in heart failure in biventricular patients, chronic low-level inflammation, and alteration of functional or structural properties of lymphatic or blood vessels. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier NCT03886935.

Co-existence of ABCB11 and DCDC2 disease: Infantile cholestasis requires both next-generation sequencing and clinical-histopathologic correlation.

A boy exhibiting conjugated hyperbilirubinemia from birth, with elevated serum gamma-glutamyl transpeptidase activity (GGT), developed liver failure unusually early (7mo); GGT concomitantly normalized. ABCB4 disease was suspected, but no ABCB4 lesion was found. The boy was instead homozygous for ABCB11 variant c.1213 T>C (p.(Cys405Arg)), which is predicted to affect protein function. Both ABCB4 and ABCB11 were normally expressed in the explanted liver, with intralobular cholestasis; however, large-duct sclerosing cholangiopathy and ductal-plate malformation also were present. The primary-cilium constituent doublecortin domain containing 2 (DCDC2) was not expressed. Co-existence of ABCB11 disease and DCDC2 disease was proposed. Further testing identified homozygosity for the canonical-receptor splice-site variant c.294-2A>G (p.?) in DCDC2. Our report emphasizes the need to integrate clinical, histological, and genetic data in patients with neonatal cholestasis.

Left ventricular mass estimation by real-time 3D echocardiography favourably competes with CMR in congenital left ventricular disease.

Assessment of left ventricular mass (LVM) is important in the evaluation of patients with congenital heart disease (CHD) and cardiac magnetic resonance imaging (CMR) is the gold standard. Recent software allows LVM calculation by real-time 3-dimensional echocardiography (RT3DE). We investigated the impact of different software analysis tools on LVM determination by CMR or RT3DE in a cohort of patients with heterogeneous left ventricular (LV) disease. 37 subjects (17 patients, mean age 18.7 y; 20 controls, mean age 13.2 y) underwent CMR and RT3DE. CMR LVM and RT3DE calculations were done using two different LV-analysis software packages for each modality: CMR i) customized software "CMR HDZ", CMR ii) "CMR ISP"; RT3DE i) "Toshiba", RT3DE ii) "Tomtec", 4D LV-Analysis Version 3.1 (built 3.1.0.258661). Intra- and interobserver variabilities were calculated. Only RT3DE-derived LVM showed significant software-dependent differences. RT3DE-derived LVM (both softwares) was significantly higher than CMR-derived LVM (both softwares). The two different methods and four evaluation software packages for LVM assessment were well correlated with each other. Intra- and interobserver variability of LVM as assessed by each single modality or software was low. Despite software dependency and overestimation of RT3DE-assessed LVM by 5 to 10%, RT3DE still competes with the gold standard, CMR, even in patients with various forms of LV disease. The use of optimized software, especially for RT3DE, should improve the accuracy of LVM assessment, overcoming LVM overestimation.

The dilemma to diagnose Wilson disease by genetic testing alone.

BACKGROUND: Wilson disease (WD) is an autosomal recessive disorder of hepatic copper excretion. About sixty per cent of patients present with liver disease. WD is considered a fatal disease if undiagnosed and/or untreated but recent data indicate that disease penetrance may not be 100%. MATERIALS AND METHODS: All patients underwent liver biopsy as part of the diagnostic workup. Genetic testing for ATP7B was performed by Sanger sequencing. RESULTS: We report on a large family with multiple affected siblings. The first patient (male, 31 years) underwent orthotopic liver transplantation (OLT) because of fulminant WD. He was homozygous for p.G710A. One asymptomatic brother (37 years) had the same mutation. He is doing well on chelation therapy. Fifteen years later, a second-degree sibling (female, 16 years) presented with fulminant WD and underwent OLT. She was compound heterozygote (p.G710A/p.G710S). Further family screening revealed a third mutation (p.V536A) in a female (21 years) and male (16 years) compound-heterozygote sibling (p.G710A/p.V536A). In both, serum ceruloplasmin and 24-hour urinary copper excretion were normal. Liver biopsy showed normal histology and a quantitative hepatic copper content within the normal range or only slightly elevated (19 and 75 µg/g dry weight, respectively). No decoppering treatment was initiated so far. CONCLUSION: Genetic testing alone is not always sufficient to diagnose WD in asymptomatic patients, and human mutation databases should be used with caution. Even patients carrying two disease-causing mutations do not necessarily have demonstrable alteration of copper metabolism. Asymptomatic siblings diagnosed by genetic screening require further testing before initiating treatment.

Vaccination Status in Pediatric Solid-Organ Transplant Recipients and Their Household Members.

OBJECTIVES: Vaccine-preventable diseases remain a major cause of morbidity and mortality in solid-organ transplant candidates and recipients. Newer recommendations include vaccination of all household members to create a herd immunity around the transplant recipient. This study evaluated the vaccination status of pediatric solid-organ transplant recipients and their household members. MATERIALS AND METHODS: We evaluated 30 pediatric solid-organ transplant recipients (14 kidney, 13 liver, 3 heart) and their household members (26 siblings, 30 parents) at time of transplant. RESULTS: Fourteen recipients (47%) received scheduled vaccinations before solid-organ transplant and were up to date for their age with their diphtheria, tetanus, pertussis; hepatitis B virus; poliomyelitis; Haemophilus influenzae type B; Streptococcus pneumoniae conjugate vaccine; and measles, mumps, and rubella vaccinations. Another 7 recipients (23%) had partially completed their schedules, only missing the second dose of the measles, mumps, and rubella vaccine. Fifteen siblings (58%) had either completed (n = 13, 50%) or partially completed (n = 2, 8%) their vaccinations. All 30 parents were either unaware of their vaccination status (n = 10, 33%) or had only incomplete vaccination records (n = 20, 67%). CONCLUSIONS: We found that most pediatric solid-organ transplant recipients to be appropriately vaccinated. However, vaccination status in household members, especially in parents, was disappointing.

Impact of the Fontan Operation on Organ Systems.

In patients having undergone the Fontan operation, besides the well discussed changes in the cardiac, pulmonary and gastrointestinal system, alterations of further organ systems including the hematologic, immunologic, endocrinological and metabolic are reported. As a medical adjunct to Fontan surgery, the systematic study of the central role of the liver as a metabolizing and synthesizing organ should allow for a better understanding of the pathomechanism underlying the typical problems in Fontan patients, and in this context, the profiling of endocrinological and metabolic patterns might offer a tool for the optimization of Fontan follow-up, targeted monitoring and specific adjunct treatment.

SPINT2 (HAI-2) missense variants identified in congenital sodium diarrhea/tufting enteropathy affect the ability of HAI-2 to inhibit prostasin but not matriptase.

The syndromic form of congenital sodium diarrhea (SCSD) is caused by bi-allelic mutations in SPINT2, which encodes a Kunitz-type serine protease inhibitor (HAI-2). We report three novel SCSD patients, two novel SPINT2 mutations and review published cases. The most common findings in SCSD patients were choanal atresia (20/34) and keratitis of infantile onset (26/34). Characteristic epithelial tufts on intestinal histology were reported in 13/34 patients. Of 13 different SPINT2 variants identified in SCSD, 4 are missense variants and localize to the second Kunitz domain (KD2) of HAI-2. HAI-2 has been implicated in the regulation of the activities of several serine proteases including prostasin and matriptase, which are both important for epithelial barrier formation. No patient with bi-allelic stop mutations was identified, suggesting that at least one SPINT2 allele encoding a protein with residual HAI-2 function is necessary for survival. We show that the SCSD-associated HAI-2 variants p.Phe161Val, p.Tyr163Cys and p.Gly168Ser all display decreased ability to inhibit prostasin-catalyzed cleavage. However, the SCSD-associated HAI-2 variants inhibited matriptase as efficiently as the wild-type HAI-2. Homology modeling indicated limited solvent exposure of the mutated amino acids, suggesting that they induce misfolding of KD2. This suggests that prostasin needs to engage with an exosite motif located on KD2 in addition to the binding loop (Cys47/Arg48) located on the first Kunitz domain in order to inhibit prostasin. In conclusion our data suggests that SCSD is caused by lack of inhibition of prostasin or a similar protease in the secretory pathway or on the plasma membrane.

Severe Deoxyguanosine Kinase Deficiency in Austria: A 6-Patient Series.

Mutations in the nuclear gene DGUOK, encoding deoxyguanosine kinase, cause an infantile hepatocerebral type of mitochondrial depletion syndrome (MDS). We report 6 MDS patients harboring bi-allelic DGUOK mutations, of which 3 are novel, including a large intragenic Austrian founder deletion. One patient was diagnosed with hepatocellular carcinoma aged 6 months, supporting a link between mitochondrial DNA depletion and tumorigenesis; liver transplantation proved beneficial with regard to both tumor treatment and psychomotor development.

Inflammatory and coagulatory parameters linked to survival in critically ill children with sepsis.

BACKGROUND: Sepsis is associated with a deflection of inflammatory and coagulative parameters, since some clotting factors are known to be involved in the host's defense against infection and inflammation. These parameters could play a crucial role in the course of sepsis and be used as prognostic markers in critically ill children. METHODS: A total of 250 critically ill pediatric patients diagnosed with sepsis were retrospectively analyzed to identify routinely measured predictors for in-hospital mortality at the peak level of C-reactive protein. Those parameters entered multivariate logistic regression analysis as well as a decision tree for survival. RESULTS: Multivariate logistic regression analysis revealed fibrinogen, platelets and activated partial thromboplastin time (aPTT) at the peak level of C-reactive protein to be predictors for survival (p = 0.03, p = 0.01 and p = 0.02, respectively). An increase in fibrinogen and platelets is linked to survival, whereas an aPTT prolongation is associated with higher mortality; adjusted odds ratios (95% CI) for an increase of 100 mg/dl in fibrinogen are 1.35 (1.04-1.82) per 50 G/l platelets 1.94 (1.3-3.29) and 0.83 (0.69-0.96) for an aPTT prolongation of 10 s. Decision tree analysis shows that a fibrinogen level below 192 mg/dl (90.9% vs. 13% mortality) is most distinctive in non-survivors. CONCLUSIONS: High levels of fibrinogen and platelets as well as a non-overshooting aPTT are associated with a higher survival rate in pediatric patients with diagnosed sepsis. In particular, hypofibrinogenemia is distinctive for a high mortality rate in septic critically ill children.

Vedolizumab use after failure of TNF-α antagonists in children and adolescents with inflammatory bowel disease.

BACKGROUND: Vedolizumab is safe and effective in adult patients with Crohn's disease (CD) and ulcerative colitis (UC); however, data in children with inflammatory bowel disease (IBD) are scarce. Therefore, we evaluated vedolizumab use in a cohort of Austrian paediatric patients with IBD. METHODS: Twelve patients (7 female; 7 CD; 5 UC), aged 8-17 years (median, 15 years), with severe IBD who received vedolizumab after tumour necrosis factor α antagonist treatment were retrospectively analysed. Clinical activity scores, relevant laboratory parameters, and auxological measures were obtained at infusion visits. RESULTS: In the CD group, 1/7 patient discontinued therapy due to a severe systemic allergic reaction; 1/7 and 2/7 patients achieved complete and partial response, respectively, at week 14; and 3/7 patients discontinued therapy due to a primary non-response or loss of response. In the UC group, complete clinical remission was achieved at weeks 2, 6, and 14 in 2/5, 1/5 and 1/5 patients respectively; partial response was observed in one patient at week 2. CD activity scores did not significantly change from baseline to week 38 (median 47.5 vs. 40 points, p = 1,0), while median UC activity scores changed from 70 to 5 points (p < 0,001). Substantial weight gain and increased albumin and haemoglobin levels were observed in both groups. CONCLUSION: These results demonstrate that vedolizumab can be an effective treatment for individual paediatric patients with IBD who are unresponsive, intolerant, or experience a loss of efficacy in other therapies. However, vedolizumab appears to be more effective in paediatric UC than in paediatric CD.

The transverse four-chamber view for the assessment of atrial tissue deformation in the fetus.

AIMS: To determine if atrial tissue deformation (peak strain, PS) and time to peak strain (TTPS) can be assessed in the fetus, with identification of best echocardiographic plane. MATERIALS AND METHODS: Pulsed-wave tissue Doppler study of a longitudinal and a transverse four-chamber view (FCV) in each of 20 healthy fetuses. Determination of PS and TTPS in regions of interest (ROI), viz., lateral walls of the right and left atria (RA, LA); comparison of values depending on section plane, with results-based discussion of the physiology of fetal atrial deformation and of possible clinical uses. RESULTS: PS and TTPS could be determined on transverse FCV in 91% of subjects and in 61% on longitudinal FCV. Transverse PS and TTPS were significantly higher than longitudinal (p = 0.0001). Transverse PS was significantly higher in RA than in LA (26.9% vs. 17.3%, p = 0.034), and transverse TTPS was significantly shorter in RA than in LA (p = 0.034). CONCLUSION: Atrial radial PS and TTPS determinations are possible in the fetus. The transverse FCV is best suited for these. The highest PS values and shortest TTPS values are found in ROI representing the RA. Our findings may contribute to detailed intrauterine assessment of atrial and ventricular myocardial function.

Standardized training for AVT pacing in paediatric patients with postoperative junctional ectopic tachycardia.

BACKGROUND: Junctional ectopic tachycardia is a serious complication of surgery for paediatric congenital heart disease. R-wave synchronized atrial (AVT) pacing, an innovative temporary pacing technique, restores atrioventricular synchrony in these patients. The method is highly effective but technically complex. A standardized training model exists for doctors but not for paediatric intensive care nurses. AIMS: This study seeks to evaluate whether a standardized programme involving simulation and vignettes increases knowledge of AVT pacing and accuracy of its documentation, as well as recognition and management of specific complications. STUDY DESIGN: This study was an experimental simulation test with before and after descriptive evaluation. METHODS: A custom-made simulation model was used in combination with standardized training. Before and after training, 10 paediatric nurse specialists were asked to document pacing, to identify complications and to intervene as necessary. Four clinical scenarios were presented: effective AVT pacing, ineffective AVT pacing, pacing with narrow interval between atrial pacing and ventricular sensing and pacemaker-induced tachycardia. Identification and management of complications were evaluated using a 3-point scale. RESULTS: Training improved the quality of documentation and complication management. At outset, documentation by 1 of 10 participants was completely correct, and after training, documentation by 8 of 10 participants was completely correct. Before training, 30% of interpretations of the four presented clinical scenarios were correct (12/40) versus 83% (33/40) after training. The decision to notify a doctor of a complication was correct in 83% (33/40) before versus 95% (38/40) after the training. CONCLUSION: Standardized simulation training improves quality and safety in AVT pacing, with more accurate documentation of the pacing mode and better recognition and management of specific complications during pacing. RELEVANCE TO CLINICAL PRACTICE: AVT pacing should be performed in conjunction with standardized simulation training in paediatric cardiac intensive care units.