Overactivity in the subthalamic nucleus (STN) is believed to contribute to the pathophysiology of Parkinson's disease. It is hypothesized that dopamine receptor agonists reduce neuronal output from the STN. The present study tests this hypothesis by using in vivo extracellular single unit recording techniques to measure neuronal activity in the STN of rats with 6-hydroxydopamineinduced lesions of the nigrostriatal pathway (a model of Parkinson's disease). As predicted, firing rates of STN neurons in lesioned rats were tonically elevated under basal conditions and were decreased by the nonselective dopamine receptor agonists apomorphine and L-3,4-dihydroxyphenylalanine (L-DOPA). STN firing rates were also decreased by the D2 receptor agonist quinpirole when administered after the D1 receptor agonist (Ϯ)-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol (SKF 38393). Results of the present study challenge the prediction that dopaminergic agonists reduce STN activity predominantly through actions at striatal dopamine D2 receptors. Firing rates of STN neurons were not altered by selective stimulation of D2 receptors and were increased by selective stimulation of D1 receptors. Moreover, there was a striking difference between the responses of the STN to D1/D2 receptor stimulation in the lesioned and intact rat; apomorphine inhibited STN firing in the lesioned rat and increased STN firing in the intact rat. These findings support the premise that therapeutic efficacy in the treatment of Parkinson's disease is associated with a decrease in the activity of the STN, but challenge assumptions about the roles of D1 and D2 receptors in the regulation of neuronal activity of the STN in both the intact and dopamine-depleted states.

The management of hypoplastic left heart syndrome (HLHS) has changed substantially over the past four decades. In the 1970s, children with HLHS could only be provided with supportive care. As a result, most of these unfortunate children died within the neonatal period. The advent of the Norwood procedure in the early 1980s has changed the prognosis for these children, and the majority now undergoing a series of three surgical stages that can support survival beyond the neonatal period and into early adulthood. This review will focus on the Norwood procedure and the other important innovations of the last half century that have improved our outlook toward children born with HLHS.

Objective: We sought to describe characteristics and operative outcomes of children who underwent repair of truncus arteriosus and identify risk factors for the occurrence of major adverse cardiac events (MACE) in the immediate postoperative period in a contemporary multicenter cohort.Methods: We conducted a retrospective review of children who underwent repair of truncus arteriosus between 2009 and 2016 at 15 centers within the United States. Patients with associated interrupted or obstructed aortic arch were excluded. MACE was defined as the need for postoperative extracorporeal membrane oxygenation, cardiopulmonary resuscitation, or operative mortality. Risk factors for MACE were identified using multivariable logistic regression analysis and reported as odds ratios (ORs) with 95% confidence intervals (CIs).Results: We reviewed 216 patients. MACE occurred in 44 patients (20%) and did not vary significantly over time. Twenty-two patients (10%) received postoperative extracorporeal membrane oxygenation, 26 (12%) received cardiopulmonary resuscitation, and 15 (7%) suffered operative mortality. With multivariable logistic regression analysis (which included adjustment for center effect), factors independently associated with MACE were failure to diagnose truncus arteriosus before discharge from the nursery (OR, 3.1; 95% CI, 1.3-7.4), cardiopulmonary bypass duration>150 minutes (OR, 3.5; 95% CI, 1.5-8.5), and right ventricle-topulmonary artery conduit diameter >50 mm/m 2 (OR, 4.7; 95% CI, 2.0-11.1).

The novel 48-h VVR was a robust predictor of outcome following paediatric cardiac surgery and outperformed the VIS and peak postoperative lactate.

INTRODUCTION: Previous reports have demonstrated that prior cardiac surgery is independently associated with in-hospital mortality after infant tracheostomy. We aimed to determine whether these infants would continue to be at increased risk for death following hospital discharge. METHODS: A retrospective review was performed on subjects < 2 y of age who recovered from tracheostomy in the pediatric ICU at our institution between January 2007 and December 2011, with follow-up to December 2013. Survival to 1 y following tracheostomy was the primary outcome variable for the study. Multivariate Cox regression analysis was then performed to determine independent risk factors for death after infant tracheostomy. RESULTS: Forty-two subjects met inclusion criteria, 18 of whom had undergone prior cardiac surgery. Twenty-six subjects (62%) were alive at 1 y post-tracheostomy. Age at tracheostomy, concomitant genetic abnormalities or prematurity, and ventilator dependence at discharge were not statistically different between survivors and those who died. Subjects who died, however, were more likely to have had cardiac surgery prior to tracheostomy (11 [69%] vs 7 [27%], P ‫؍‬ .008) and had longer hospital stay (median 3.4 months [interquartile range: 2.6 -4.6] vs 2.2 months [interquartile range: 1.1-3.5], P ‫؍‬ .045). Multivariate Cox regression analysis revealed only prior cardiac surgery to be independently associated with decreased survival after tracheostomy (hazard ratio 4.7, 95% CI 1.3-16.4, P ‫؍‬ .02). CONCLUSIONS: Prior cardiac surgery is independently associated with decreased survival within 1 y following tracheostomy. Clinicians and families of infants with prior cardiac surgery in whom tracheostomy after cardiac surgery is deemed necessary should consider this risk when planning long-term care.

Objectives: To describe the epidemiology of extubation failure and identify risk factors for its occurrence in a multicenter population of neonates undergoing surgery for congenital heart disease. Study Design:We conducted a prospective observational study of neonates ≤ 30 days of age who underwent cardiac surgery at seven centers within the United States in 2015. Extubation failure was defined as reintubation within 72 hours of the first planned extubation. Risk factors were identified using multivariable logistic regression analysis and reported as odds ratios (OR) with 95% confidence intervals (CI). Multivariable logistic regression analysis was also conducted to examine the relationship between extubation failure and worse clinical outcome, defined as hospital length-of-stay in the upper 25% or operative mortality.

Objective In a multicenter cohort of neonates recovering from cardiac surgery, we sought to describe the epidemiology of extubation failure and its variability across centers, identify risk factors, and determine its impact on outcomes. Methods We analyzed prospectively collected clinical registry data on all neonates undergoing cardiac surgery in the Pediatric Cardiac Critical Care Consortium database from October 2013 to July 2015. Extubation failure was defined as reintubation less than 72 hours after the first planned extubation. Risk factors were identified using multivariable logistic regression with generalized estimating equations to account for within-center correlation. Results The cohort included 899 neonates from 14 Pediatric Cardiac Critical Care Consortium centers; 14% were premature, 20% had genetic abnormalities, 18%had major extracardiac anomalies, and 74%underwent surgery with cardiopulmonary bypass. Extubation failure occurred in 103 neonates (11%), within 24 hours in 61%. Unadjusted rates of extubation failure ranged from 5% to 22% across centers; this variability was unchanged after adjusting for procedural complexity and airway anomaly. After multivariable analysis, only airway anomaly was identified as an independent risk factor for extubation failure (odds ratio, 3.1; 95%confidence interval, 1.4–6.7; P = .01). Neonates who failed extubation had a greater median postoperative length of stay (33 vs 23 days, P < .001) and in-hospital mortality (8% vs 2%, P = .002). Conclusions This multicenter study showed that 11% of neonates recovering from cardiac surgery fail initial postoperative extubation. Only congenital airway anomaly was independently associated with extubation failure. We observed a 4-fold variation in extubation failure rates across hospitals, suggesting a role for collaborative quality improvement to optimize outcomes.

Objectives: We aimed to further validate the vasoactive-ventilation-renal score as a predictor of outcome in patients recovering from surgery for congenital heart disease. We also sought to determine the optimal time point within the early recovery period at which the vasoactive-ventilation-renal score should be measured. Methods: We prospectively reviewed consecutive patients recovering from cardiac surgery within our intensive care unit between January 2015 and June 2015. The vasoactive-ventilation-renal score was calculated at 6, 12, 24, and 48 hours postoperatively as follows: vasoactive-ventilation-renal score ¼ ventilation index þ vasoactive-inotrope score þ D creatinine [change in serum creatinine from baseline*10]. Primary outcome of interest was prolonged hospital length of stay, defined as length of stay in the upper 25%. Receiver operating characteristic curves were generated, and areas under the curve with 95% confidence intervals were calculated for all time points. Multivariable logistic regression modeling also was performed. Results: We reviewed 164 patients with a median age of 9.25 months (interquartile range, 2.6-58 months). Median length of stay was 8 days (interquartile range, 5-17.5 days). The area under the curve value for the vasoactive-ventilation-renal score as a predictor of prolonged length of stay (>17.5 days) was greatest at 12 hours postoperatively (area under the curve ¼ 0.93; 95% confidence interval, 0.89-0.97). On multivariable regression analysis, after adjustment for potential confounders, the 12-hour vasoactive-ventilation-renal score remained a strong predictor of prolonged hospital length of stay (odds ratio, 1.15; 95% confidence interval, 1.10-1.20). Conclusions: In a heterogeneous population of patients undergoing surgery for congenital heart disease, the novel vasoactive-ventilation-renal score calculated in the early postoperative recovery period can be a strong predictor of prolonged hospital length of stay.