Risk factors for reoperation after relief of congenital subaortic stenosis

Background: Congenital subaortic stenosis entails a lesion spectrum, ranging from an isolated obstructive membrane, to complex tunnel narrowing of the left outflow associated with other cardiac defects. We review our experience with this anomaly, and analyze risk factors leading to restenosis requiring reoperation. Methods: From 1994 to 2006, 58 children (median age 4.3 years, range 7 days-13.7 years) underwent primary relief of subaortic stenosis. Patients were divided into simple lesions (n=43) or complex stenosis (n=15) associated with other major cardiac defects. Age, pre- and postoperative gradient over the left outflow, associated aortic or mitral valve insufficiency, chromosomal anomalies, arteria lusoria, and operative technique (membrane resection (22) vs associated myectomy (34) vs Konno (2)) were analyzed as risk factors for reoperation (Kaplan-Meier, Cox regression). Results: There was no operative mortality. Median follow-up spanned 2.7 years (range 0.1-10), with one late death at 4 months. Reoperation was required for recurrent stenosis in 11 patients (19%) at 2.6 years (range 0.3-7.5) after initial surgery. Risk factors for reoperation included complex subaortic stenosis (p=0.003), younger age (p=0.012), postoperative residual gradient (p=0.019), and the presence of an arteria lusoria (p=0.014). For simple lesions, no variable achieved significance for stenosis recurrence. Conclusions: Surgical relief of congenital subaortic stenosis, even with complex defects, yields excellent results. Reoperation is not infrequent, and should be anticipated with younger age at operation, complex defects, residual postoperative gradient, and an arteria lusoria. Myectomy concomitant to membrane resection, even in simple lesions, does not provide enhanced freedom from reoperation, and should be tailored to anatomic finding

Network Farthest-Point Diagrams

Consider the continuum of points along the edges of a network, i.e., an undirected graph with positive edge weights. We measure distance between these points in terms of the shortest path distance along the network, known as the network distance. Within this metric space, we study farthest points. We introduce network farthest-point diagrams, which capture how the farthest points---and the distance to them---change as we traverse the network. We preprocess a network G such that, when given a query point q on G, we can quickly determine the farthest point(s) from q in G as well as the farthest distance from q in G. Furthermore, we introduce a data structure supporting queries for the parts of the network that are farther away from q than some threshold R > 0, where R is part of the query. We also introduce the minimum eccentricity feed-link problem defined as follows. Given a network G with geometric edge weights and a point p that is not on G, connect p to a point q on G with a straight line segment pq, called a feed-link, such that the largest network distance from p to any point in the resulting network is minimized. We solve the minimum eccentricity feed-link problem using eccentricity diagrams. In addition, we provide a data structure for the query version, where the network G is fixed and a query consists of the point p.Comment: A preliminary version of this work was presented at the 24th Canadian Conference on Computational Geometr

Propionic acidemia in a previously healthy adolescent with acute onset of dilated cardiomyopathy

Propionic acidemia (PA) is a rare autosomal recessive organic aciduria resulting from defects in propionyl-CoA-carboxylase (PCC), a key enzyme of intermediate energy metabolism. PA mostly manifests during the neonatal period, when affected newborns develop severe metabolic acidosis and hyperammonemia. We present a previously healthy teenager, who suffered from acute fatigue and breathlessness. The patient was tachycardic, displayed a precordial heave and a systolic murmur. Cardiac investigations revealed severe dilated cardiomyopathy (DCM). Biochemical work up led to the diagnosis of PA. Remarkably, this patient of consanguineous Hispanic origin was in a good general health condition before the acute onset of DCM. Diagnosis of PA was confirmed by enzymatic and molecular genetic analysis, the latter revealing a novel homozygous mutation in the PCCB gene (c.1229G > A; p.R410Q). Residual PCC enzyme activity of approximately 14% of normal was detected in patient's lymphocytes and fibroblasts, thereby providing a possible explanation for the hitherto asymptomatic phenotype. Conclusion: Isolated DCM, although rare, can be the leading and/or sole symptom of late-onset PA. Therefore, patients with DCM should receive a comprehensive diagnostic evaluation including selective screening for inborn errors of metabolism

Propionic acidemia in a previously healthy adolescent with acute onset of dilated cardiomyopathy

Propionic acidemia (PA) is a rare autosomal recessive organic aciduria resulting from defects in propionyl-CoA-carboxylase (PCC), a key enzyme of intermediate energy metabolism. PA mostly manifests during the neonatal period, when affected newborns develop severe metabolic acidosis and hyperammonemia. We present a previously healthy teenager, who suffered from acute fatigue and breathlessness. The patient was tachycardic, displayed a precordial heave and a systolic murmur. Cardiac investigations revealed severe dilated cardiomyopathy (DCM). Biochemical work up led to the diagnosis of PA. Remarkably, this patient of consanguineous Hispanic origin was in a good general health condition before the acute onset of DCM. Diagnosis of PA was confirmed by enzymatic and molecular genetic analysis, the latter revealing a novel homozygous mutation in the PCCB gene (c.1229G > A; p.R410Q). Residual PCC enzyme activity of approximately 14 % of normal was detected in patient’s lymphocytes and fibroblasts, thereby providing a possible explanation for the hitherto asymptomatic phenotype. Conclusion: Isolated DCM, although rare, can be the leading and/or sole symptom of late-onset PA. Therefore, patients with DCM should receive a comprehensive diagnostic evaluation including selective screening for inborn errors of metabolism

Involvement of parents in critical incidents in a neonatal-paediatric intensive care unit

BACKGROUND: With more liberal visiting hours in paediatric intensive care practice, parents' presence at the bedside has increased. Parents may thus become involved in critical incidents as contributors or detectors of critical incidents or they may be affected by critical incidents. METHODS: Voluntary, anonymous, non-punitive critical incident reporting system. Parents' involvement in critical incidents has been evaluated retrospectively (January 2002 to August 2007). The reports were analysed regarding involvement of parents, age of child, unit (paediatric intensive care or intermediate neonatal nursery), critical incident severity, critical incident category, actual or potential harm to patient and/or parent (minor, moderate, major), delay between the critical incident and its detection, and implemented system changes. RESULTS: Overall, 2494 critical incidents have been reported. There were 101 critical incidents with parental involvement: parents as contributors to critical incident (18; 0.7%), parents discovering a critical incident (11; 0.4%), parents affected by critical incident (72; 2.9%). The most vulnerable categories regarding contribution and detection were drugs, line/drain disconnection, trauma and hygiene. Ten critical incidents precipitated by parents were of moderate severity and seven of potential major severity (six line/drain disconnections). The majority of the events (six) detected by parents were of potential moderate severity and four were of major severity. CONCLUSION: Because of their presence at the bedside, parents in the paediatric intensive care unit are inevitably involved in safety issues. It is not the parents' duty to guarantee the safety for their children, but parents should be encouraged to report anything that worries them. Only an established safety culture allows parents to articulate their concerns

Prognostic Evaluation of Mortality after Pediatric Resuscitation Assisted by Extracorporeal Life Support

To improve survival rates during cardiopulmonary resuscitation (CPR), some patients are put on extracorporeal life support (ECLS) during active resuscitation (ECPR). Our objective was to assess the clinical outcomes after pediatric ECPR in Switzerland and to determine pre-ECPR prognostic factors for mortality. The present study is a retrospective analysis. The study setting included three pediatric intensive care units in Switzerland that use ECPR. All patients ( 7.00; 2 points if ≤ 7.00; 3 points if ≤ 6.85; 6 points if ≤ 6.60. The area under the receiver-operating characteristic curve was 0.74. The positive predictive value of a score ≥ 9 was 94%. In our population, a score based on three variables easily available prior to ECLS initiation had good discrimination and could appropriately predict mortality. This score now needs validation in a larger population

The morbidity and mortality conference in pediatric intensive care as a means for improving patient safety

OBJECTIVES: To present our experience in an interdisciplinary and interprofessional morbidity and mortality conference, with special emphasis on its usefulness in improving patient safety. DESIGN: Retrospective analysis. SETTING: Tertiary interdisciplinary neonatal PICU. PATIENTS: Morbidity and mortality conference minutes on 48 patients (newborns to 17 yr), January 2009 to June 2014. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The authors' PICU implemented a morbidity and mortality conference guideline in 2009 using a system-based approach to identify medical errors, their contributing factors, and possible solutions. In the subsequent 5.5 years, there were 44 mortality conferences (of 181 deaths [27%] over the same period) and four morbidity conferences. The median death/morbidity event-morbidity and mortality conference interval was 90 days (range, 7 d to 1.5 yr). The median age of patients was 4 months (range, newborn to 17 years). In six cases, the primary reason for PICU admission was a treatment complication. Unsafe processes/medical errors were identified and discussed in 37 morbidity and mortality conferences (77%). In seven cases, new autopsy findings prompted the discussion of a possible error. The 48 morbidity and mortality conferences identified 50 errors, including 30 in which an interface problem was a contributing factor. Fifty-four improvements were identified in 34 morbidity and mortality conferences. Four morbidity and mortality conferences discussed specific ethical issues. CONCLUSIONS: From our experience, we have found that the interdisciplinary and interprofessional morbidity and mortality conference has the potential to reveal unsafe processes/medical errors, in particular, diagnostic and communication errors and interface problems. When formatted as a nonhierarchical tool inviting contributions from all staff levels, the morbidity and mortality conference plays a key role in the system approach to medical errors

Propionic acidemia in a previously healthy adolescent with acute onset of dilated cardiomyopathy

Propionic acidemia (PA) is a rare autosomal recessive organic aciduria resulting from defects in propionyl-CoA-carboxylase (PCC), a key enzyme of intermediate energy metabolism. PA mostly manifests during the neonatal period, when affected newborns develop severe metabolic acidosis and hyperammonemia. We present a previously healthy teenager, who suffered from acute fatigue and breathlessness. The patient was tachycardic, displayed a precordial heave and a systolic murmur. Cardiac investigations revealed severe dilated cardiomyopathy (DCM). Biochemical work up led to the diagnosis of PA. Remarkably, this patient of consanguineous Hispanic origin was in a good general health condition before the acute onset of DCM. Diagnosis of PA was confirmed by enzymatic and molecular genetic analysis, the latter revealing a novel homozygous mutation in the PCCB gene (c.1229G > A; p.R410Q). Residual PCC enzyme activity of approximately 14 % of normal was detected in patient’s lymphocytes and fibroblasts, thereby providing a possible explanation for the hitherto asymptomatic phenotype. Conclusion: Isolated DCM, although rare, can be the leading and/or sole symptom of late-onset PA. Therefore, patients with DCM should receive a comprehensive diagnostic evaluation including selective screening for inborn errors of metabolism

The effect of ductal diameter on surgical and medical closure of patent ductus arteriosus in preterm neonates: size matters

OBJECTIVE: We sought to analyze the effect of patent ductus arteriosus diameter on treatment success in premature neonates. METHODS: Among 537 consecutive neonates born between 1985 and 2005 with a diagnosed patent ductus arteriosus, 201 premature patients (<35 weeks' gestation) treated for a hemodynamically significant patent ductus arteriosus were retrospectively reviewed. Two groups were compared: group MED (n = 154; successful treatment with indomethacin) and group FAIL (n = 47; failure of medication to reduce the patent ductus arteriosus diameter to hemodynamic insignificance). RESULTS: After unsuccessful medical treatment, 33 patients required surgical patent ductus arteriosus closure, 12 died before further possible treatment, and 2 were discharged home without clinical symptoms but with an open patent ductus arteriosus. Mean patent ductus arteriosus diameter in the FAIL group (2.8 +/- 0.9 mm) was significantly larger than that in the MED group (2.4 +/- 0.6 mm, P < .01). Assisted respiration time (ventilation plus continuous positive airway pressure) before patent ductus arteriosus closure was longer in the FAIL group (20 days) than in the MED group (9 days, P < .001) but was similar after patent ductus arteriosus closure. By using an index of patent ductus arteriosus diameter squared/birth weight (in square millimeters per kilogram), a cutoff value of less than 9 mm2/kg correctly predicts medical patent ductus arteriosus closure in 87.5% of patients. Values of greater than 9 mm2/kg correctly predict medication failure in 41.5% of patients. CONCLUSIONS: In preterm babies requiring surgical patent ductus arteriosus closure, longer respiration times reflect a delay while attempting medical treatment, but respiration time is equally short between groups after shunt elimination. Medical treatment, although a valid first option, is likely to fail with larger patent ductus arteriosus diameters and lower birth weights. Unwarranted assisted respiration and corresponding hospital stay might be shortened by earlier surgical referral for patent ductus arteriosus closure in preterm babies with a patent ductus arteriosus index of greater than 9 mm2/kg