Generalizing Diffusion Tensor Imaging of Physis and Metaphysis: Evaluation of Variability [Meeting Abstract]
Purpose or Case Report: To assess variability in diffusion tensor imaging of the physis and metaphysis (DTI-P/M) of the distal femur between scanners, observers, tractography software, and resolution. Methods & Materials: We prospectively obtained DTI-P/M (20 directions, b values of 0 and 600 sec/mm2) in 11 healthy subjects (5 males, 6 females) ages 10-15 (mean 12.54) and quantified tract volume, tract length, and number of tracts in the distal femoral physis. Each subject was imaged in both GE and Siemens 3T units, and the sequence was performed twice in each session with voxel sizes of 2x2x3mm or 1x1x2mm and gap sizes of 0mm and 0.6 mm (22 studies). We compared interobserver variability (with two observers) using hand-drawn regions of interest in the distal femur physis between two tractography software, Trackvis (FACT algorithm) and DSI Studio (Euler algorithm), both with a 40o angular threshold. For DSI Studio, we set the tracking threshold to 0.1, length range to 0-200mm, and seed termination to 1000000. We compared tract number, length, and volume and fractional anisotropy, between the 22 studies using Spearman's correlation and Bland-Altman (BA) plots.
Result(s): Correlation between Siemens and GE was significant between Siemens with 2x2x3mm voxel size and 0.6mm gap with GE 1x1x2mm voxel size and 0mm gap (rho = 0.93, p<10^- 15). Bland-Altman plots normalizing for voxel size between Siemens and GE showed no bias in inter-scanner variability (bias -5.76, BA limits of agreement (LOA) -24.31 and 12.78), nor was there significant intrascanner variability between consecutive runs of either Siemens (bias 0.565, BA LOA -10.31 and 9.18) or GE (bias 0.309, BA LOA -2.08 and 2.69). The 95% confidence intervals for the inter-scan (Mean=1.109, 95%-CI [- 0.84 3.06]) and intra-scan (Mean=0.3, 95%-CI [-0.31 0.91]) both included zero confirming no significant bias between scanners (p<0.05). Trackvis, the current standard for DTI-P/M, had high interobserver agreement (rho = 0.95) whereas DSI Studio showed poor interobserver agreement (rho = 0.29).
Conclusion(s): DTI-P/M shows high GE and Siemens inter- and intra-scanner reproducibility and low variability. Trackvis has low interobserver variability for tractography generation
Prevalence and Risk Factors of Neurologic Manifestations in Hospitalized Children Diagnosed with Acute SARS-CoV-2 or MIS-C
BACKGROUND:Our objective was to characterize the frequency, early impact, and risk factors for neurological manifestations in hospitalized children with acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or multisystem inflammatory syndrome in children (MIS-C). METHODS:Multicenter, cross-sectional study of neurological manifestations in children aged <18Â years hospitalized with positive SARS-CoV-2 test or clinical diagnosis of a SARS-CoV-2-related condition between January 2020 and April 2021. Multivariable logistic regression to identify risk factors for neurological manifestations was performed. RESULTS:Of 1493 children, 1278 (86%) were diagnosed with acute SARS-CoV-2 and 215 (14%) with MIS-C. Overall, 44% of the cohort (40% acute SARS-CoV-2 and 66% MIS-C) had at least one neurological manifestation. The most common neurological findings in children with acute SARS-CoV-2 and MIS-C diagnosis were headache (16% and 47%) and acute encephalopathy (15% and 22%), both PÂ <Â 0.05. Children with neurological manifestations were more likely to require intensive care unit (ICU) care (51% vs 22%), PÂ <Â 0.001. In multivariable logistic regression, children with neurological manifestations were older (odds ratio [OR] 1.1 and 95% confidence interval [CI] 1.07 to 1.13) and more likely to have MIS-C versus acute SARS-CoV-2 (OR 2.16, 95% CI 1.45 to 3.24), pre-existing neurological and metabolic conditions (OR 3.48, 95% CI 2.37 to 5.15; and OR 1.65, 95% CI 1.04 to 2.66, respectively), and pharyngeal (OR 1.74, 95% CI 1.16 to 2.64) or abdominal pain (OR 1.43, 95% CI 1.03 to 2.00); all PÂ <Â 0.05. CONCLUSIONS:In this multicenter study, 44% of children hospitalized with SARS-CoV-2-related conditions experienced neurological manifestations, which were associated with ICU admission and pre-existing neurological condition. Posthospital assessment for, and support of, functional impairment and neuroprotective strategies are vitally needed.
Air embolism to multiorgan failure: A rare complication of catheter removal in a pediatric patient [Meeting Abstract]
INTRODUCTION: The pathological manifestations of vascular air embolism (VAE) depend on the volume and rapidity of gas entry, and result from mechanical obstruction, leading to ischemia and inflammatory reactions to air as a foreign body. Physiologic effects on the cardiovascular, neurologic, or pulmonary systems may be trivial or catastrophic.
METHOD(S): A 17-year-old boy with anti-MOG syndrome was admitted for plasmapheresis for optic neuritis. Minutes after removal of his internal jugular central venous catheter (CVC), he developed paresthesias, chest discomfort, and sudden onset cough, progressing to unresponsiveness. Noncontrast head CT was negative for acute intracranial process. Upon transfer to the PICU, the patient decompensated further, requiring intubation and initiation of vasoactives for refractory shock. CT angiogram of the head and neck was unremarkable. Initial brain MRI showed diffuse leptomeningeal enhancement concerning for infection, however extensive infectious workup was negative. Repeat MRI revealed numerous scattered foci of acute and lateacute infarcts consistent with an embolic event. Cardiac workup was significant for an EKG with anterolateral ST elevation, elevated serum troponin, and TEE demonstrating left ventricular hypokinesia and a trivial PFO. Cardiac MRI confirmed an intraventricular septal infarct. The sudden onset of signs of neurologic and cardiopulmonary compromise with temporal relation to CVC manipulation led to the clinical diagnosis of VAE.
RESULT(S): We describe a rare case of CVC-associated VAE in a pediatric patient resulting in neurologic injury and cardiopulmonary collapse. When air enters the vasculature, it can migrate along three major pathways: via pulmonary circulation, paradoxically via intra-cardiac shunt, or to the cerebral venous system via retrograde ascension. In most described cases, emboli migrate along only one or two of these pathways. In this case, the patient developed ARDS, cardiogenic shock, and multiple ischemic strokes, suggesting embolic migration along all three pathways. There is inadequate awareness of VAE as a potentially fatal complication of CVC use. Though a rare complication, the vast majority of catheter-associated VAE are largely preventable with focused instruction and reinforcement through enhanced supervision
Outcomes and Adverse Effects With Peramivir for the Treatment of Influenza H1N1 in Critically Ill Pediatric Patients
OBJECTIVES/OBJECTIVE:Influenza is an environmental pathogen and infection presents as a range from asymptomatic to fulminant illness. Though treatment is supportive, antiviral agents have a role in the management of infection. Pediatric use of peramivir is largely based on reports and extrapolations of pharmacokinetic data. We seek to describe efficacy and safety of peramivir in critically ill pediatric patients. METHODS:This is a retrospective, institutional review board-approved chart review of all patients under 21 years of age, admitted to the PICU, and treated with peramivir for influenza H1N1 infection between January 1, 2016, and March 31, 2016, at a single-center, 12-bed PICU. The primary outcome was time to sustained resolution of fever; secondary outcomes included dose, duration, and adverse effects of peramivir therapy. RESULTS:Seven patients were included with median age of 3.7 years. Median time to sustained resolution of fever was 49.3 hours, median duration of mechanical ventilation was 14.2 days, median ICU LOS was 18.7 days, and hospital LOS was 24.7 days. No patients suffered mortality. Three patients experienced leukopenia, one of which experienced a concurrent neutropenia. Three patients experienced hyperglycemia, 2 experienced hypertension, 1 experienced increased aspartate aminotransferase and increased alanine aminotransferase, and 1 experienced diarrhea. All adverse events assessed were classified as possible using published adverse event causality assessments. CONCLUSIONS:Peramivir has been shown to be an effective therapy for the treatment of influenza H1N1 in critically ill pediatric patients. In our experience with 7 pediatric patients, peramivir was well tolerated at typical durations of therapy; however, increased vigilance is warranted during prolonged courses or in patients with reasons for altered pharmacokinetics and pharmacodynamics.
High frequency percussive ventilation in a child with severe acute respiratory distress syndrome from pulmonary hemorrhage [Meeting Abstract]
Aims & Objectives: High frequency percussive ventilation (HFPV) rapidly delivers subphysiologic tidal volumes using a volume-diffusive respirator and provides similar or improved oxygenation and ventilation at lower peak, mean, and end-expiratory pressures when compared with conventional ventilation (CV). We present the case of a child with acute respiratory distress syndrome (ARDS) from pulmonary hemorrhage treated with HFPV. Methods Case Report Results A ventilator-dependent 5-year-old male with pyruvate dehydrogenase deficiency presented with acute hypoxemic respiratory failure. Chest radiography showed bilateral pulmonary infiltrates and tracheal aspirate revealed hemosiderin laden macrophages. Methylprednisolone and empiric antibiotics were administered for pulmonary hemorrhage and severe ARDS. The patient was placed on high-frequency oscillatory ventilation (HFOV) then HFPV (Figure 1). Subsequent dislodgement of a blood clot was followed by improvement in OI and chest radiography (Figure 2). The patient was discharged on home ventilator settings on HD#11. (Figure prsented). Conclusions HFPV has been shown to decrease morbidity and mortality by improving mucociliary clearance. To our knowledge this is the first reported case of HFPV use in a pediatric patient with ARDS from pulmonary hemorrhage. Early implementation of HFPV may be a safe and effective ECMO-sparing strategy to improve oxygenation in patients with ARDS due to pulmonary hemorrhage
Blood plasma levels of heart disease biomarker cardiac troponin I are significantly increased in alopecia areata affected individuals [Meeting Abstract]
MALIGNANT HYPERTHERMIA-ASSOCIATED LIVER FAILURE TREATED WITH N-ACETYLCYSTEINE IN A 5-YEAR-OLD BOY [Meeting Abstract]
IV Enoxaparin in Pediatric and Cardiac ICU Patients
OBJECTIVES: To report our experience with the use of IV enoxaparin in neonatal and pediatric patients in the ICU. DESIGN: We performed a case control from January 1, 2009, to June 30, 2012, comparing patients that received IV enoxaparin to controls that received subcutaneous enoxaparin. Cases were matched to controls in a 1:2 manner. IV enoxaparin doses were infused over 30 minutes and anti-Factor Xa levels were drawn 4 hours after the start of the IV infusion or 4 hours after a subcutaneous dose. SETTING: The pediatric and cardiac ICUs of a tertiary/quaternary, free-standing, academic children's hospital. PATIENTS: Forty-five neonatal and pediatric patients receiving prophylactic or therapeutic enoxaparin. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Fifteen cases and 30 controls were included. Of 15 patients, 13 received IV enoxaparin for treatment and two received IV enoxaparin for prophylaxis as compared with 25 of 30 controls receiving subcutaneous enoxaparin for treatment and five receiving subcutaneous enoxaparin for prophylaxis. The ages for the cases ranged from 21 days to 16 years with a median weight of 5 kg, and the ages for controls ranged from 10 days to 23 years with a median weight of 31 kg. The median duration of IV therapy was 11 days (range, 1-120 d) and the median duration for subcutaneous therapy was 15 days (range, 3-85 d). The mean initial IV dose was 1.14 +/- 0.38 mg/kg/dose q12h, and the mean initial subcutaneous dose was 0.85 +/- 0.2 mg/kg/dose subcutaneous q12h (p = 0.003). The mean therapeutic IV dose was 1.31 +/- 0.52 mg/kg/dose q12h, and the mean therapeutic subcutaneous dose was 0.9 +/- 0.3 mg/kg/dose q12h (p = 0.016). There were no adverse events reported related to bleeding, thrombosis, or hypersensitivity in any of the cases or controls evaluated. CONCLUSION: The pharmacodynamics of a 30-minute IV enoxaparin infusion was found to produce therapeutic 4 hour anti-Factor Xa levels similar to subcutaneous doses. Although this was a small study, there were no adverse events, suggesting the safety profile of IV enoxaparin may be similar to subcutaneous dosing with the added benefit of less pain associated with IV dosing. These findings suggest that IV enoxaparin may be a viable option for anticoagulating critically ill children and its use warrants further study.
ELEVATED PROCALCITONIN AFTER ANTI-THYMOCYTE GLOBULIN FOR FAMILIAL HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS [Meeting Abstract]
Stress response in critical illness
Sepsis brings about neuroendocrine dysfunction in children that differs significantly from that of adults and can thus be difficult to interpret and manage. Aggressive treatment of sepsis with appropriate and judicious use of antibiotics remains a top priority. Strict glycemic control in children has been associated with significant risk of hypoglycemia, which may independently contribute to morbidity and mortality. Timely initiation of hydrocortisone in persistently hypotensive children with fluid-refractory, catecholamine-resistant shock is controversial, but its use in children with suspected or proven adrenal insufficiency is suggested. Fluid and electrolyte abnormalities must be corrected. Treatment of thyroid dysfunction has been shown to be beneficial in certain specific populations but cannot be extrapolated to all septic patients with the current available data.