Johnny Millar

Predictors of survival after single-ventricle palliation: the impact of right ventricular dominance.

OBJECTIVES This study examined survival after surgical palliation in children with single-ventricle physiology. BACKGROUND Contemporary surgical outcomes for the entire population of newborns undergoing single-ventricle palliation are unclear. METHODS In a single-center review of 499 consecutive patients undergoing univentricular palliation from 1990 to 2008, predictors of mortality were determined using multivariate risk analysis, stratified for each post-operative stay and interim states. RESULTS After 2000, the population comprised more patients with dominant right ventricle (66% vs. 36%) and hypoplastic left heart syndrome (HLHS) (47% vs. 13%). Median age at bidirectional cavopulmonary shunt (BCPS) decreased from 15 months (10 to 22 months) before 2000 to 4 months (3.3 to 9 months) thereafter. Survival rates at 1, 5, and 10 years were, respectively, 82% (95% confidence interval [CI]: 79% to 85%), 74% (95% CI: 70% to 78%), and 71% (95% CI: 67% to 75%). Throughout the study, atrioventricular valve regurgitation (hazard ratio [HR]: 1.8; p = 0.008), not having transposition (HR: 2.0; p = 0.013), and heterotaxia (HR: 2.0; p = 0.026) were predictors of mortality. The most potent risk factor was right ventricular (RV) dominance (HR: 2.2; p = 0.001) because of its impact before BCPS. HR for death in patients with RV dominance went from 2.8 (95% CI: 1.4 to 5.7; p = 0.005) before BCPS to 1.0 (95% CI: 0.5 to 2.1; p = 0.98) thereafter. Survival of patients with RV dominance, adjusted for the risk factors noted here, improved over the study period (p = 0.001). CONCLUSIONS Considerable mortality is still observed during the first years of life among patients with single ventricle. RV dominance is the most important risk factor for death but only before BCPS.

Elective decompression of the left ventricle in pediatric patients may reduce the duration of venoarterial extracorporeal membrane oxygenation.

We aimed to determine the effect of elective left heart decompression at the time of initiation of central venoarterial extracorporeal membrane oxygenation (VA ECMO) on VA ECMO duration and clinical outcomes in children in a single tertiary ECMO referral center with a large pediatric population from a national referral center for pediatric cardiac surgery. We studied 51 episodes of VA ECMO in a historical cohort of 49 pediatric patients treated between the years 1990 and 2013 in the Paediatric Intensive Care Unit (PICU) of the Royal Childrens Hospital, Melbourne. The cases had a variety of diagnoses including congenital cardiac abnormalities, sepsis, myocarditis, and cardiomyopathy. Left heart decompression as an elective treatment or an emergency intervention for left heart distension was effectively achieved by a number of methods, including left atrial venting, blade atrial septostomy, and left ventricular cannulation. Elective left heart decompression was associated with a reduction in time on ECMO (128 h) when compared with emergency decompression (236 h) (P = 0.013). Subgroup analysis showed that ECMO duration was greatest in noncardiac patients (elective 138 h, emergency 295 h; P = 0.02) and in patients who died despite both emergency decompression and ECMO (elective 133 h, emergency 354 h; P = 0.002). As the emergency cases had a lower pH, a higher PaCO2 , and a lower oxygenation index and were treated with a higher mean airway pressure, positive end-expiratory pressure, and respiratory rate prior to receiving VA ECMO, we undertook multivariate linear regression modeling to show that only PaCO2 and the timing of left heart decompression were associated with ECMO duration. However, elective left heart decompression was not associated with a reduction in length of PICU stay, duration of mechanical ventilation, or duration of oxygen therapy. Elective left heart decompression was not associated with improved ECMO survival or survival to PICU discharge. Elective left heart decompression may reduce ECMO duration and has therefore the potential to reduce ECMO-related complications. A prospective, randomized controlled trial is indicated to study this intervention further.

Five-Year Survival of Children With Chronic Critical Illness in Australia and New Zealand.

Objective:Outcomes for children with chronic critical illness are not defined. We examined the long-term survival of these children in Australia and New Zealand. Design:All cases of PICU chronic critical illness with length of stay more than 28 days and age 16 years old or younger in Australia and New Zealand from 2000 to 2011 were studied. Five-year survival was analyzed using Kaplan-Meir estimates, and risk factors for mortality evaluated using Cox regression. Setting:All PICUs in Australia and New Zealand. Patients:Nine hundred twenty-four children with chronic critical illness. Intervention:None. Measurements and Main Results:Nine hundred twenty-four children were admitted to PICU for longer than 28 days on 1,056 occasions, accounting for 1.3% of total admissions and 23.5% of bed days. Survival was known for 883 of 924 patients (95.5%), with a median follow-up of 3.4 years. The proportion with primary cardiac diagnosis increased from 27% in 2000–2001 to 41% in 2010–2011. Survival was 81.4% (95% CI, 78.6–83.9) to PICU discharge, 70% (95% CI, 66.7–72.8) at 1 year, and 65.5% (95% CI, 62.1–68.6) at 5 years. Five-year survival was 64% (95% CI, 58.7–68.6) for children admitted in 2000–2005 and 66% (95% CI, 61.7–70) if admitted in 2006–2011 (log-rank test, p = 0.37). After adjusting for admission severity of illness using the Paediatric Index of Mortality 2 score, predictors for 5-year mortality included bone marrow transplant (hazard ratio, 3.66; 95% CI, 2.26–5.92) and single-ventricle physiology (hazard ratio, 1.98; 95% CI, 1.37–2.87). Five-year survival for single-ventricle physiology was 47.2% (95% CI, 34.3–59.1) and for bone marrow transplantation 22.8% (95% CI, 8.7–40.8). Conclusions:Two thirds of children with chronic critical illness survive for at-least 5 years, but there was no improvement between 2000 and 2011. Cardiac disease constitutes an increasing proportion of pediatric chronic critical illness. Bone marrow transplant recipients and single-ventricle physiology have the poorest outcomes.

Extracorporeal membrane modality conversions

We report the case of a patient with cardiovascular and respiratory failure due to severe anaphylaxis requiring multiple extracorporeal membrane oxygenation (ECMO) cannulation strategies to provide adequate oxygen delivery and ventilatory support during a period of rapid physiological change. ECMO provides partial or complete support of oxygenation-ventilation and circulation. The choice of which ECMO modality to use is governed by anatomical (vessel size, cardiovascular anatomy and previous surgeries) and physiological (respiratory and/or cardiac failure) factors. The urgency with which ECMO needs to be implemented (emergency cardiopulmonary resuscitation (eCPR), urgent, elective) and the institutional experience will also influence the type of ECMO provided. Here we describe a 12-year-old schoolgirl who, having been resuscitated with peripheral veno-venous (VV) ECMO for severe hypoxemia due to status asthmaticus in the setting of acute anaphylaxis, required escalation to peripheral veno-arterial (VA) ECMO for precipitous cardiovascular deterioration. Insufficient oxygen delivery for adequate cellular metabolic function and possible cerebral hypoxia due to significant differential hypoxia necessitated ECMO modification. After six days of central (transthoracic) VA ECMO support and 21 days of intensive care unit (ICU) care, she made a complete recovery with no neurological sequelae. The use of ECMO support warrants careful consideration of the interplay of a patient’s pathophysiology and extracorporeal circuit dynamics. Particular emphasis should be placed on the potential for mismatch between cardiovascular and respiratory support as well as the need to meet metabolic demands through adequate cerebral, coronary and systemic oxygenation. Cannulation strategies occasionally require alteration to meet and anticipate the patient’s evolving needs.

Trends in PICU admission and survival rates in children in Australia and New Zealand following cardiac arrest

Objectives: To describe the temporal trends in rates of PICU admissions and mortality for out-of-hospital cardiac arrests and in-hospital cardiac arrests admitted to PICU over the last decade. Design: Multicenter, retrospective analysis of prospectively collected binational data of the Australian and New Zealand Paediatric Intensive Care Registry. All nine specialist PICUs in Australia and New Zealand were included. Patients: All children admitted between 2003 and 2012 to PICU who were less than 16 years old at the time of admission. Interventions: None. Measurements and Main Results: There were a total of 71,425 PICU admissions between 2003 and 2012. Overall, cardiac arrest accounted for 1.86% of all admissions (1,329 cases), including 677 cases of in-hospital cardiac arrest (51.0%) and 652 cases of out-of-hospital cardiac arrest (49.0%). Over the last decade, there has been a 29.6% increase in the odds of PICU survival for all pediatric admissions (odds ratio, 1.30; 95% CI, 1.09–1.54). By contrast, there was no significant improvement in the risk-adjusted odds of survival for out-of-hospital cardiac arrest admissions (odds ratio, 1.03; 95% CI, 0.50–2.10; p = 0.94) or in-hospital cardiac arrest admissions (odds ratio, 1.03; 95% CI, 0.54–1.98; p = 0.92). Conclusions: Despite improvements in overall outcomes in children admitted to Australian and New Zealand PICUs, survival of children admitted with out-of-hospital cardiac arrest or in-hospital cardiac arrest did not change significantly over the past decade.

Ventricular assist device support in patients with single ventricles: the Melbourne experience

OBJECTIVES The capacity and limitations of ventricular assist device (VAD) support in single-ventricle physiology remains poorly understood. We aimed to review our experience in the use of VAD support in the single-ventricle circulation to determine its feasibility in this population. METHODS We reviewed our experience with VAD support in patients with single ventricles over the past 25 years. Fifty-seven patients received 64 runs of VAD support between 1990 and 2015 at a median age of 13 days [interquartile range (IQR) 4.1-99.4 days], of which 55 were supported for post-cardiotomy failure. The majority of patients received short-term VAD support, while 4 patients were either directly supported (1) or transitioned onto the Berlin Heart EXCOR (3). RESULTS The median duration of support was 3.5 days (IQR 2.8-5.2 days). Twelve patients suffered significant neurological complications, and thromboembolic events occurred in 8 patients. Twenty-nine of the 55 patients were successfully weaned off support (53%). There were 37 inpatient deaths, with a survival-to-hospital discharge rate of 33% (18 of 55). Of the 4 patients supported after early Fontan failure, 3 died. Having a higher mean arterial blood pressure on initiation of VAD support was the only significant predictor of death (hazards ratio 1.08; 95% confidence interval 1.03-1.14; P = 0.002). Patients who required a second run of support had higher hospital mortality (83% vs 63%; P = 0.84). Of the hospital survivors, 12 patients (63%) remain alive without heart transplantation at median 7.2 years (IQR 3.5-14.0) post VAD support. CONCLUSIONS VAD support in patients with a single ventricle has a high hospital mortality, with 1 of 3 patients surviving to discharge. Systemic VAD support is likely futile in the setting of early Fontan failure or when re-initiation of support is required.

Complications of intrathoracic lines placed during cardiac surgery

FIGURE 1. Techniques of insertion of a direct right atrial line to prevent the li before the entry point into the right atrium. B, A 7-0 polydioxanone suture is sec the right atrium. From the Department of Cardiac Surgery, The Royal Children’s Hospital, Melbourne; Department of Pediatrics, University of Melbourne, Melbourne; Paediatric Intensive Care Unit, The Royal Children’s Hospital, Melbourne; and Murdoch Children’s Research Institute, Melbourne, Victoria, Australia. This research project was supported by the Victorian Government’s Operational Infrastructure Support Program. Disclosures: Yves d’Udekem is a Career Development Fellow of The National Heart Foundation of Australia (CR 10M 5339) and National Health and Medical Research Council Clinician Practitioner Fellow (1082186). All other authors have nothing to disclose with regard to commercial support. Received for publication July 23, 2014; revisions received Nov 3, 2014; accepted for publication Nov 28, 2014; available ahead of print Jan 13, 2015. Address for reprints: Yves d’Udekem, MD, PhD, Department of Cardiac Surgery, Royal Children’s Hospital, Flemington Rd, Parkville, Melbourne, Victoria 3052, Australia (E-mail: yves.dudekem@rch.org.au). J Thorac Cardiovasc Surg 2015;149:1212-3 0022-5223/

Laryngeal ultrasound detects a high incidence of vocal cord paresis after aortic arch repair in neonates and young children

36.00 Copyright 2015 by The American Association for Thoracic Surgery http://dx.doi.org/10.1016/j.jtcvs.2014.11.082

Extracorporeal membrane oxygenation for Kawasaki disease: two case reports and the Extracorporeal Life Support Organization experience 1999–2015

Objectives: To determine the incidence of vocal cord paresis (VCP) after neonatal aortic arch repair/Norwood‐type procedure, and the effectiveness of noninvasive laryngeal ultrasound in detecting VCP compared with gold standard invasive nasoendoscopy. Methods: Fifty‐two patients who underwent an arch repair (39 of 52; 75%) or Norwood‐type procedure (13 of 52; 25%) via sternotomy between April 1, 2015, and April 30, 2017 underwent laryngeal ultrasound (50 of 52; 96%) and/or flexible fiber optic nasoendoscopy (39 of 52; 75%) at 48 to 72 hours after endotracheal extubation. Primary arch diagnoses were coarctation in 56% (29 of 52), hypoplastic left heart syndrome in 17% (9 of 52), isolated hypoplastic arch in 17% (9 of 52), and interrupted aortic arch in 10% (5 of 52). The median patient age at surgery was 5.5 days (interquartile range, 4.0–12.5 days). Fifteen patients (15 of 52; 29%) required preoperative intubation. Results: Left VCP was present in 59% (23 of 39) of patients on nasoendoscopy and in 59% (27 of 46) of patients on laryngeal ultrasound, and 4 additional patients had inconclusive ultrasound results. There was agreement between the results of nasoendoscopy and conclusive ultrasound in all cases. The overall sensitivity, specificity, positive and negative predictive values, and Cohens kappa coefficient of laryngeal ultrasound compared with nasoendoscopy for the detection of left VCP were 95%, 88%, 91%, 93%, and 0.83, respectively. On multivariable analysis, preoperative intubation and arch repair techniques other than the Norwood procedure were associated with left VCP (odds ratio, 12.7; P = .03; and 14.1; P = .03, respectively). Conclusions: There is a high incidence of VCP after arch repair via sternotomy. Laryngeal ultrasound seems to be an effective and noninvasive method for detecting VCP in neonates and young children.

Five-Year Survival of Children With Chronic Critical Illness in Australia and New Zealand

Kawasaki disease is usually a limited illness of early childhood. However, life-threatening cardiac manifestations can occur, either at acute presentation or as a consequence of coronary arterial involvement. We report the successful use of veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) for cardiac support in two children with Kawasaki disease: one with acute Kawasaki disease shock syndrome, the other with complications of coronary arteritis and subsequent surgery. We also reviewed the reported experience in the ELSO database and available literature.