Establishment of prophylactic enoxaparin dosing recommendations to achieve targeted anti-factor Xa concentrations in children with CHD

Background Enoxaparin may be used to prevent central venous catheter-related thrombosis in patients with CHD. We aimed to determine whether current enoxaparin dosing regimens effectively achieve anti-factor Xa concentrations within prophylactic goal ranges in this patient population. Methods We implemented a formal protocol aimed at reducing central venous catheter-related thrombosis in children with CHD in January, 2016. Standard empiric prophylactic enoxaparin dosing regimens were used – for example, 0.75 mg/kg/dose every 12 hours for patients <2 months of age and 0.5 mg/kg/dose every 12 hours for patients ⩾2 months of age – with anti-factor Xa goal range of 0.25–0.49 IU/ml. Patients <2 years of age who received enoxaparin and had at least one valid steady-state anti-factor Xa measurement between 25 January, 2016 and 31 August, 2016 were retrospectively reviewed. Results During the study period, 47 patients had 186 anti-factor Xa concentrations measured, of which 20 (11%) were above and 112 (60%) were below the prophylactic goal range. Anti-factor Xa concentrations within the goal range were ultimately achieved in 31 patients. Median dose required to achieve anti-factor Xa concentrations within the prophylactic range was 0.89 mg/kg/dose (25, 75%: 0.75, 1.11) for patients <2 months (n=23 patients) and 0.79 mg/kg/dose (25, 75%: 0.62, 1.11) for patients ⩾2 months (n=8 patients). Conclusions Enoxaparin doses required to achieve prophylactic anti-factor Xa concentrations in young children with CHD were consistently higher than the currently recommended prophylactic dosing regimens. Further study is needed to determine whether dose titration to achieve prophylactic anti-factor Xa concentrations is effective in preventing central venous catheter-related thrombosis

Prior Cardiac Surgery is Independently Associated with Decreased Survival following Infant Tracheostomy

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

Nicardipine for Hypertension following Aortic Coarctectomy and Superior Cavopulmonary Anastomosis

Background: Literature on the use of nicardipine, a dihydropyridine calcium channel antagonist, in children recovering from cardiac surgery is sparse and, to our knowledge, nonexistent in children with single ventricle anatomy. We aimed to report our experience with nicardipine in these patient populations. Methods: We performed a retrospective review of children recovering from aortic coarctectomy or superior cavopulmonary anastomoses who received nicardipine for hypertension at our institution between 2007 and 2013. Hemodynamic variables prior to and after nicardipine initiation were compared using paired t tests. Results: Seven children recovering from aortic coarctectomy (median age 8.6 months, range: 1.5 months-7.9 years) and four children recovering from superior cavopulmonary anastomosis (median age: seven months, range: five-nine months) were reviewed. For all patients, at six hours after initiation of nicardipine, mean systolic blood pressure was significantly decreased, 123 ± 19 versus 103 ± 14 mm Hg (P = .001), as were diastolic blood pressure, 68 ± 20 versus 53.5 ± 10 mm Hg (P = .041), and sodium nitroprusside dose, 4.3 ± 2.9 versus 1.3 ± 1.7 mcg/kg/min (P = .002). Further, within 24 hours, serum lactate decreased from 1.45 ± 0.82 to 0.81 ± 0.29 mg/dL (P = .016). Heart rate, blood urea nitrogen, and serum creatinine measurements were statistically unchanged. Conclusions: Nicardipine effectively decreased blood pressure without apparent adverse events in a small cohort of children with postoperative hypertension while recovering from aortic coarctectomy or superior cavopulmonary anastomosis. Further research comparing nicardipine to more conventional titratable antihypertensive agents in these patient populations is warranted

Zombies in Western Culture

"Why has the zombie become such a pervasive figure in twenty-first-century popular culture? John Vervaeke, Christopher Mastropietro and Filip Miscevic seek to answer this question by arguing that particular aspects of the zombie, common to a variety of media forms, reflect a crisis in modern Western culture. The authors examine the essential features of the zombie, including mindlessness, ugliness and homelessness, and argue that these reflect the outlook of the contemporary West and its attendant zeitgeists of anxiety, alienation, disconnection and disenfranchisement. They trace the relationship between zombies and the theme of secular apocalypse, demonstrating that the zombie draws its power from being a perversion of the Christian mythos of death and resurrection. Symbolic of a lost Christian worldview, the zombie represents a world that can no longer explain itself, nor provide us with instructions for how to live within it. The concept of 'domicide' or the destruction of home is developed to describe the modern crisis of meaning that the zombie both represents and reflects. This is illustrated using case studies including the relocation of the Anishinaabe of the Grassy Narrows First Nation, and the upheaval of population displacement in the Hellenistic period. Finally, the authors invoke and reformulate symbols of the four horseman of the apocalypse as rhetorical analogues to frame those aspects of contemporary collapse that elucidate the horror of the zombie. Zombies in Western Culture: A Twenty-First Century Crisis is required reading for anyone interested in the phenomenon of zombies in contemporary culture. It will also be of interest to an interdisciplinary audience including students and scholars of culture studies, semiotics, philosophy, religious studies, eschatology, anthropology, Jungian studies, and sociology.

Multicenter Validation of the Vasoactive-Ventilation-Renal Score as a Predictor of Prolonged Mechanical Ventilation After Neonatal Cardiac Surgery

Objectives: We sought to validate the Vasoactive-Ventilation-Renal score, a novel disease severity index, as a predictor of outcome in a multicenter cohort of neonates who underwent cardiac surgery. Design: Retrospective chart review. Setting: Seven tertiary-care referral centers. Patients: Neonates defined as age less than or equal to 30 days at the time of cardiac surgery. Interventions: Ventilation index, Vasoactive-Inotrope Score, serum lactate, and Vasoactive-Ventilation-Renal score were recorded for three postoperative time points: ICU admission, 6 hours, and 12 hours. Peak values, defined as the highest of the three measurements, were also noted. Vasoactive-Ventilation-Renal was calculated as follows: ventilation index + Vasoactive-Inotrope Score + Δ creatinine (change in creatinine from baseline × 10). Primary outcome was prolonged duration of mechanical ventilation, defined as greater than 96 hours. Receiver operative characteristic curves were generated, and abilities of variables to correctly classify prolonged duration of mechanical ventilation were compared using area under the curve values. Multivariable logistic regression modeling was also performed. Measurements and Main Results: We reviewed 275 neonates. Median age at surgery was 7 days (25th–75th percentile, 5–12 d), 86 (31%) had single ventricle anatomy, and 183 (67%) were classified as Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Category 4 or 5. Prolonged duration of mechanical ventilation occurred in 89 patients (32%). At each postoperative time point, the area under the curve for prolonged duration of mechanical ventilation was significantly greater for the Vasoactive-Ventilation-Renal score as compared to the ventilation index, Vasoactive-Inotrope Score, and serum lactate, with an area under the curve for peak Vasoactive-Ventilation-Renal score of 0.82 (95% CI, 0.77–0.88). On multivariable analysis, peak Vasoactive-Ventilation-Renal score was independently associated with prolonged duration of mechanical ventilation, odds ratio (per 1 unit increase): 1.08 (95% CI, 1.04–1.12). Conclusions: In this multicenter cohort of neonates who underwent cardiac surgery, the Vasoactive-Ventilation-Renal score was a reliable predictor of postoperative outcome and outperformed more traditional measures of disease complexity and severity

Prevalence and Risk Factors for Upper Airway Obstruction after Pediatric Cardiac Surgery

Objective To determine the prevalence of and risk factors for extrathoracic upper-airway obstruction after pediatric cardiac surgery. Study design A retrospective chart review was performed on 213 patients younger than 18 years of age who recovered from cardiac surgery in our multidisciplinary intensive care unit in 2012. Clinically significant upper-airway obstruction was defined as postextubation stridor with at least one of the following: receiving more than 2 corticosteroid doses, receiving helium-oxygen therapy, or reintubation. Multivariate logistic regression analysis was performed to determine independent risk factors for this complication. Results Thirty-five patients (16%) with extrathoracic upper-airway obstruction were identified. On bivariate analysis, patients with upper-airway obstruction had greater surgical complexity, greater vasoactive medication requirements, and longer postoperative durations of endotracheal intubation. They also were more difficult to calm while on mechanical ventilation, as indicated by greater infusion doses of narcotics and greater likelihood to receive dexmedetomidine or vecuronium. On multivariable analysis, adjunctive use of dexmedetomedine or vecuronium (OR 3.4, 95% CI 1.4-8) remained independently associated with upper-airway obstruction. Conclusion Extrathoracic upper-airway obstruction is relatively common after pediatric cardiac surgery, especially in children who are difficult to calm during endotracheal intubation. Postoperative upper-airway obstruction could be an important outcome measure in future studies of sedation practices in this patient population

Risk Factors for Extubation Failure following Neonatal Cardiac Surgery

Objective: Extubation failure after neonatal cardiac surgery has been associated with considerable postoperative morbidity, although data identifying risk factors for its occurrence are sparse. We aimed to determine risk factors for extubation failure in our neonatal cardiac surgical population. Design: Retrospective chart review. Setting: Urban tertiary care free-standing children’s hospital. Patients: Neonates (0–30 d) who underwent cardiac surgery at our institution between January 2009 and December 2012 was performed. Interventions: Extubation failure was defined as reintubation within 72 hours after extubation from mechanical ventilation. Multivariate logistic regression analysis was performed to determine independent risk factors for extubation failure. Measurements and Main Results: We included 120 neonates, of whom 21 (17.5%) experienced extubation failure. On univariate analysis, patients who failed extubation were more likely to have genetic abnormalities (24% vs 6%; p = 0.023), hypoplastic left heart (43% vs 17%; p = 0.009), delayed sternal closure (38% vs 12%; p = 0.004), postoperative infection prior to extubation (38% vs 11%; p = 0.002), and longer duration of mechanical ventilation (median, 142 vs 58 hr; p = 0.009]. On multivariate analysis, genetic abnormalities, hypoplastic left heart, and postoperative infection remained independently associated with extubation failure. Furthermore, patients with infection who failed extubation tended to receive fewer days of antibiotics prior to their first extubation attempt when compared with patients with infection who did not fail extubation (4.9 ± 2.6 vs 7.3 ± 3; p = 0.073). Conclusions: Neonates with underlying genetic abnormalities, hypoplastic left heart, or postoperative infection were at increased risk for extubation failure. A more conservative approach in these patients, including longer pre-extubation duration of antibiotic therapy for postoperative infections, may be warranted

Passive Peritoneal Drainage versus Pleural Drainage after Pediatric Cardiac Surgery

Background: We aimed to determine whether infants undergoing cardiac surgery would more efficiently attain negative fluid balance postoperatively with passive peritoneal drainage as compared to traditional pleural drainage. Methods: A prospective, randomized study including children undergoing repair of tetralogy of Fallot (TOF) or atrioventricular septal defect (AVSD) was completed between September 2011 and June 2013. Patients were randomized to intraoperative placement of peritoneal catheter or right pleural tube in addition to the requisite mediastinal tube. The primary outcome measure was fluid balance at 48 hours postoperatively. Variables were compared using t tests or Fisher exact tests as appropriate. Results: A total of 24 patients were enrolled (14 TOF and 10 AVSD), with 12 patients in each study group. Mean fluid balance at 48 hours was not significantly different between study groups, −41 ± 53 mL/kg in patients with periteonal drainage and −9 ± 40 mL/kg in patients with pleural drainage (P = .10). At 72 hours however, postoperative fluid balance was significantly more negative with peritoneal drainage, −52.4 ± 71.6 versus +2.0 ± 50.6 (P = .04). On subset analysis, fluid balance at 48 hours in patients with AVSD was more negative with peritoneal drainage as compared to pleural, −82 ± 51 versus −1 ± 38 mL/kg, respectively (P = .02). Fluid balance at 48 hours in patients with TOF was not significantly different between study groups. Conclusion: Passive peritoneal drainage may more effectively facilitate negative fluid balance when compared to pleural drainage after pediatric cardiac surgery, although this benefit is not likely universal but rather dependent on the patient’s underlying physiology

Vasoactive-ventilation-renal score reliably predicts hospital length of stay after surgery for congenital heart disease

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 = ventilation index + vasoactive-inotrope score + Δ 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 = 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

Variation in extubation failure rates after neonatal congenital heart surgery across Pediatric Cardiac Critical Care Consortium hospitals

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