Nudging During Pediatric Intensive Care Conferences With Family Members: Retrospective Analysis of Transcripts From a Single-Center, 2015-2019.

OBJECTIVES: Nudging, a behavioral economics concept, subtly influences decision-making without coercion or limiting choice. Despite its frequent use, the specific application of nudging techniques by clinicians in shared decision-making (SDM) is understudied. Our aim was to analyze clinicians' use of nudging in a curated dataset of family care conferences in the PICU. DESIGN: Between 2019 and 2020, we retrospectively studied and coded 70 previously recorded care conference transcripts that involved physicians and families from 2015 to 2019. We focused on decision-making discussions examining instances of nudging, namely salience, framing, options, default, endowment, commission, omission, recommend, expert opinion, certainty, and social norms. Nudging instances were categorized by decision type, including tracheostomy, goals of care, or procedures. SETTING: Single-center quaternary pediatric facility with general and cardiac ICUs. PATIENTS: None. INTERVENTIONS: None. MEASUREMENTS: We assessed the pattern and frequency of nudges in each transcript. MAIN RESULTS: Sixty-three of the 70 transcripts contained SDM episodes. These episodes represented a total of 11 decision categories based on the subject matter of nudging instances, with 308 decision episodes across all transcripts (median [interquartile range] 5 [4-6] per conference). Tracheostomy was the most frequently discussed decision. A total of 1096 nudging instances were identified across the conferences, with 8 (6-10) nudge types per conference. The most frequent nudging strategy used was gain frame (203/1096 [18.5%]), followed by loss frame (150/1096 [13.7%]). CONCLUSIONS: Nudging is routinely employed by clinicians to guide decision-making, primarily through gain or loss framing. This retrospective analysis aids in understanding nudging in care conferences: it offers insight into potential risks and benefits of these techniques; it highlights ways in which their application has been used by caregivers; and it may be a resource for future trainee curriculum development.

Extracorporeal Membrane Oxygenation as a Bridge to Chimeric Antigen Receptor T-cell Therapy for Severe Refractory Sepsis in the Setting of Relapsed Refractory Pediatric Acute Lymphoblastic Leukemia: A Case Report.

Pediatric oncology patients with sepsis are at higher risk of morbidity and mortality compared with pediatric patients without malignancy. Historically, patients with relapsed and/or refractory disease were not considered candidates for aggressive life support strategies including extracorporeal membrane oxygenation support. CASE SUMMARY: We report a 4-year-old female with relapsed refractory pre-B cell acute lymphoblastic leukemia preparing for chimeric antigen receptor T cell therapy with tisagenlecleucel who was admitted with fever and neutropenia. She progressed to refractory septic shock secondary to Escherichia coli bacteremia and required escalation of hemodynamic support to venoarterial extracorporeal membrane oxygenation cannulation. She cleared her E. coli bacteremia, was decannulated, subsequently received her chimeric antigen receptor T-cell therapy, and was declared disease free 1 month from her initial presentation. CONCLUSION: The ability to provide chimeric antigen receptor T-cell therapy at designated institutions can augment extracorporeal membrane oxygenation candidacy discussions in oncology patients with relapsed disease and may make extracorporeal membrane oxygenation candidacy for oncology patients with refractory sepsis more favorable.

The aquaporin-4 inhibitor AER-271 blocks acute cerebral edema and improves early outcome in a pediatric model of asphyxial cardiac arrest.

BACKGROUND: Cerebral edema after cardiac arrest (CA) is associated with increased mortality and unfavorable outcome in children and adults. Aquaporin-4 mediates cerebral water movement and its absence in models of ischemia improves outcome. We investigated early and selective pharmacologic inhibition of aquaporin-4 in a clinically relevant asphyxial CA model in immature rats in a threshold CA insult that produces primarily cytotoxic edema in the absence of blood-brain barrier permeability. METHODS: Postnatal day 16-18 Sprague-Dawley rats were studied in our established 9-min asphyxial CA model. Rats were randomized to aquaporin-4 inhibitor (AER-271) vs vehicle treatment, initiated at return of spontaneous circulation. Cerebral edema (% brain water) was the primary outcome with secondary assessments of the Neurologic Deficit Score (NDS), hippocampal neuronal death, and neuroinflammation. RESULTS: Treatment with AER-271 ameliorated early cerebral edema measured at 3 h after CA vs vehicle treated rats. This treatment also attenuated early NDS. In contrast to rats treated with vehicle after CA, rats treated with AER-271 did not develop significant neuronal death or neuroinflammation as compared to sham. CONCLUSION: Early post-resuscitation aquaporin-4 inhibition blocks the development of early cerebral edema, reduces early neurologic deficit, and blunts neuronal death and neuroinflammation post-CA.

Intracranial Pressure Trajectories: A Novel Approach to Informing Severe Traumatic Brain Injury Phenotypes.

OBJECTIVES: Intracranial pressure in traumatic brain injury is dynamic and influenced by factors like injury patterns, treatments, and genetics. Existing studies use time invariant summary intracranial pressure measures thus potentially losing critical information about temporal trends. We identified longitudinal intracranial pressure trajectories in severe traumatic brain injury and evaluated whether they predicted outcome. We further interrogated the model to explore whether ABCC8 polymorphisms (a known cerebraledema regulator) differed across trajectory groups. DESIGN: Prospective observational cohort. SETTING: Single-center academic medical center. PATIENTS: Four-hundred four severe traumatic brain injury patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We used group-based trajectory modeling to identify hourly intracranial pressure trajectories in days 0-5 post traumatic brain injury incorporating risk factor adjustment (age, sex, Glasgow Coma Scale 6score, craniectomy, primary hemorrhage pattern). We compared 6-month outcomes (Glasgow Outcome Scale, Disability Rating Scale, mortality) and ABCC8 tag-single-nucleotide polymorphisms associated with cerebral edema (rs2237982, rs7105832) across groups. Regression models determined whether trajectory groups predicted outcome. A six trajectory group model best fit the data, identifying cohorts differing in initial intracranial pressure, evolution, and number/proportion of spikes greater than 20 mm Hg. There were pattern differences in age, hemorrhage type, and craniectomy rates. ABCC8 polymorphisms differed across groups. GOS (p = 0.006), Disability Rating Scale (p = 0.001), mortality (p < 0.0001), and rs2237982 (p = 0.035) differed across groups. Unfavorable outcomes were surprisingly predicted by both low intracranial pressure trajectories and sustained intracranial hypertension. Intracranial pressure variability differed across groups (p < 0.001) and may reflect preserved/impaired intracranial elastance/compliance. CONCLUSIONS: We employed a novel approach investigating longitudinal/dynamic intracranial pressure patterns in traumatic brain injury. In a risk adjusted model, six groups were identified and predicted outcomes. If validated, trajectory modeling may be a first step toward developing a new, granular approach for intracranial pressure phenotyping in conjunction with other phenotyping tools like biomarkers and neuroimaging. This may be particularly relevant in light of changing traumatic brain injury demographics toward the elderly.

Glibenclamide Produces Region-Dependent Effects on Cerebral Edema in a Combined Injury Model of Traumatic Brain Injury and Hemorrhagic Shock in Mice.

Cerebral edema is critical to morbidity/mortality in traumatic brain injury (TBI) and is worsened by hypotension. Glibenclamide may reduce cerebral edema by inhibiting sulfonylurea receptor-1 (Sur1); its effect on diffuse cerebral edema exacerbated by hypotension/resuscitation is unknown. We aimed to determine if glibenclamide improves pericontusional and/or diffuse edema in controlled cortical impact (CCI) (5m/sec, 1 mm depth) plus hemorrhagic shock (HS) (35 min), and compare its effects in CCI alone. C57BL/6 mice were divided into five groups (n = 10/group): naïve, CCI+vehicle, CCI+glibenclamide, CCI+HS+vehicle, and CCI+HS+glibenclamide. Intravenous glibenclamide (10 min post-injury) was followed by a subcutaneous infusion for 24 h. Brain edema in injured and contralateral hemispheres was subsequently quantified (wet-dry weight). This protocol brain water (BW) = 80.4% vehicle vs. 78.3% naïve, p < 0.01) but was not reduced by glibenclamide (I%BW = 80.4%). Ipsilateral edema also developed in CCI alone (I%BW = 80.2% vehicle vs. 78.3% naïve, p < 0.01); again unaffected by glibenclamide (I%BW = 80.5%). Contralateral (C) %BW in CCI+HS was increased in vehicle (78.6%) versus naive (78.3%, p = 0.02) but unchanged in CCI (78.3%). At 24 h, glibenclamide treatment in CCI+HS eliminated contralateral cerebral edema (C%BW = 78.3%) with no difference versus naïve. By 72 h, contralateral cerebral edema had resolved (C%BW = 78.5 ± 0.09% vehicle vs. 78.3 ± 0.05% naïve). Glibenclamide decreased 24 h contralateral cerebral edema in CCI+HS. This beneficial effect merits additional exploration in the important setting of TBI with polytrauma, shock, and resuscitation. Contralateral edema did not develop in CCI alone. Surprisingly, 24 h of glibenclamide treatment failed to decrease ipsilateral edema in either model. Interspecies dosing differences versus prior studies may play an important role in these findings. Mechanisms underlying brain edema may differ regionally, with pericontusional/osmolar swelling refractory to glibenclamide but diffuse edema (via Sur1) from combined injury and/or resuscitation responsive to this therapy. TBI phenotype may mandate precision medicine approaches to treat brain edema.

Regionally clustered ABCC8 polymorphisms in a prospective cohort predict cerebral oedema and outcome in severe traumatic brain injury.

OBJECTIVE: ABCC8 encodes sulfonylurea receptor 1, a key regulatory protein of cerebral oedema in many neurological disorders including traumatic brain injury (TBI). Sulfonylurea-receptor-1 inhibition has been promising in ameliorating cerebral oedema in clinical trials. We evaluated whether ABCC8 tag single-nucleotide polymorphisms predicted oedema and outcome in TBI. METHODS: DNA was extracted from 485 prospectively enrolled patients with severe TBI. 410 were analysed after quality control. ABCC8 tag single-nucleotide polymorphisms (SNPs) were identified (Hapmap, r2>0.8, minor-allele frequency >0.20) and sequenced (iPlex-Gold, MassArray). Outcomes included radiographic oedema, intracranial pressure (ICP) and 3-month Glasgow Outcome Scale (GOS) score. Proxy SNPs, spatial modelling, amino acid topology and functional predictions were determined using established software programs. RESULTS: Wild-type rs7105832 and rs2237982 alleles and genotypes were associated with lower average ICP (ß=-2.91, p=0.001; ß=-2.28, p=0.003) and decreased radiographic oedema (OR 0.42, p=0.012; OR 0.52, p=0.017). Wild-type rs2237982 also increased favourable 3-month GOS (OR 2.45, p=0.006); this was partially mediated by oedema (p=0.03). Different polymorphisms predicted 3-month outcome: variant rs11024286 increased (OR 1.84, p=0.006) and wild-type rs4148622 decreased (OR 0.40, p=0.01) the odds of favourable outcome. Significant tag and concordant proxy SNPs regionally span introns/exons 2-15 of the 39-exon gene. CONCLUSIONS: This study identifies four ABCC8 tag SNPs associated with cerebral oedema and/or outcome in TBI, tagging a region including 33 polymorphisms. In polymorphisms predictive of oedema, variant alleles/genotypes confer increased risk. Different variant polymorphisms were associated with favourable outcome, potentially suggesting distinct mechanisms. Significant polymorphisms spatially clustered flanking exons encoding the sulfonylurea receptor site and transmembrane domain 0/loop 0 (juxtaposing the channel pore/binding site). This, if validated, may help build a foundation for developing future strategies that may guide individualised care, treatment response, prognosis and patient selection for clinical trials.

Pre-clinical models in pediatric traumatic brain injury-challenges and lessons learned.

PURPOSE: Despite the enormity of the problem and the lack of new therapies, research in the pre-clinical arena specifically using pediatric traumatic brain injury (TBI) models is limited. In this review, some of the key models addressing both the age spectrum of pediatric TBI and its unique injury mechanisms will be highlighted. Four topics will be addressed, namely, (1) unique facets of the developing brain important to TBI model development, (2) a description of some of the most commonly used pre-clinical models of severe pediatric TBI including work in both rodents and large animals, (3) a description of the pediatric models of mild TBI and repetitive mild TBI that are relatively new, and finally (4) a discussion of challenges, gaps, and potential future directions to further advance work in pediatric TBI models. METHODS: This narrative review on the topic of pediatric TBI models was based on review of PUBMED/Medline along with a synthesis of information on key factors in pre-clinical and clinical developmental brain injury that influence TBI modeling. RESULTS: In the contemporary literature, six types of models have been used in rats including weight drop, fluid percussion injury (FPI), impact acceleration, controlled cortical impact (CCI), mechanical shaking, and closed head modifications of CCI. In mice, studies are largely restricted to CCI. In large animals, FPI and rotational injury have been used in piglets and shake injury has also been used in lambs. Most of the studies have been in severe injury models, although more recently, studies have begun to explore mild and repetitive mild injuries to study concussion. CONCLUSIONS: Given the emerging importance of TBI in infants and children, the morbidity and mortality that is produced, along with its purported link to the development of chronic neurodegenerative diseases, studies in these models merit greater systematic investigations along with consortium-type approaches and long-term follow-up to translate new therapies to the bedside.

Cerebrospinal Fluid NLRP3 is Increased After Severe Traumatic Brain Injury in Infants and Children.

BACKGROUND: Inflammasome-mediated neuroinflammation may cause secondary injury following traumatic brain injury (TBI) in children. The pattern recognition receptors NACHT domain-, Leucine-rich repeat-, and PYD-containing Protein 1 (NLRP1) and NLRP3 are essential components of their respective inflammasome complexes. We sought to investigate whether NLRP1 and/or NLRP3 abundance is altered in children with severe TBI. METHODS: Cerebrospinal fluid (CSF) from children (n = 34) with severe TBI (Glasgow coma scale score [GCS] ≤8) who had externalized ventricular drains (EVD) placed for routine care was evaluated for NLRP1 and NLRP3 at 0-24, 25-48, 49-72, and >72 h post-TBI and was compared to infection-free controls that underwent lumbar puncture to rule out CNS infection (n = 8). Patient age, sex, initial GCS, mechanism of injury, treatment with therapeutic hypothermia, and 6-month Glasgow outcome score were collected. RESULTS: CSF NLRP1 was undetectable in controls and detected in 2 TBI patients at only <24 h post-TBI. CSF NLRP3 levels were increased in TBI patients compared with controls at all time points, p < 0.001. TBI patients ≤4 years of age had higher peak NLRP3 levels versus patients >4 (15.50 [3.65-25.71] vs. 3.04 [1.52-8.87] ng/mL, respectively; p = 0.048). Controlling for initial GCS in multivariate analysis, peak NLRP3 >6.63 ng/mL was independently associated with poor outcome at 6 months. CONCLUSIONS: In the first report of NLRP1 and NLRP3 in childhood neurotrauma, we found that CSF NLRP3 is elevated in children with severe TBI and independently associated with younger age and poor outcome. Future studies correlating NLRP3 with other markers of inflammation and response to therapy are warranted.

ABCC8 Single Nucleotide Polymorphisms are Associated with Cerebral Edema in Severe TBI.

OBJECTIVE: Cerebral edema (CE) in traumatic brain injury (TBI) is the consequence of multiple underlying mechanisms and is associated with unfavorable outcomes. Genetic variability in these pathways likely explains some of the clinical heterogeneity observed in edema development. A role for sulfonylurea receptor-1 (Sur1) in CE is supported. However, there are no prior studies examining the effect of genetic variability in the Sur1 gene (ABCC8) on the development of CE. We hypothesize that ABCC8 single nucleotide polymorphisms (SNPs) are predictive of CE. METHODS: DNA was extracted from 385 patients. SNPs in ABCC8 were genotyped using the Human Core Exome v1.2 (Illumina). CE measurements included acute CT edema, mean and peak intracranial pressure (ICP), and need for decompressive craniotomy. RESULTS: Fourteen SNPs with minor allele frequency >0.2 were identified. Four SNPS rs2283261, rs3819521, rs2283258, and rs1799857 were associated with CE measures. In multiple regression models, homozygote-variant genotypes in rs2283261, rs3819521, and rs2283258 had increased odds of CT edema (OR 2.45, p = 0.007; OR 2.95, p = 0.025; OR 3.00, p = 0.013), had higher mean (ß = 3.13, p = 0.000; ß = 2.95, p = 0.005; ß = 3.20, p = 0.008), and peak ICP (ß = 8.00, p = 0.001; ß = 7.64, p = 0.007; ß = 6.89, p = 0.034). The homozygote wild-type genotype of rs1799857 had decreased odds of decompressive craniotomy (OR 0.47, p = 0.004). CONCLUSIONS: This is the first report assessing the impact of ABCC8 genetic variability on CE development in TBI. Minor allele ABCC8 SNP genotypes had increased risk of CE, while major SNP alleles were protective-potentially suggesting an evolutionary advantage. These findings could guide risk stratification, treatment responders, and the development of novel targeted or gene-based therapies against CE in TBI and other neurological disorders.

Sulfonylurea Receptor-1: A Novel Biomarker for Cerebral Edema in Severe Traumatic Brain Injury.

OBJECTIVES: Cerebral edema is a key poor prognosticator in traumatic brain injury. There are no biomarkers identifying patients at-risk, or guiding mechanistically-precise therapies. Sulfonylurea receptor-1-transient receptor potential cation channel M4 is upregulated only after brain injury, causing edema in animal studies. We hypothesized that sulfonylurea receptor-1 is measurable in human cerebrospinal fluid after severe traumatic brain injury and is an informative biomarker of edema and outcome. DESIGN: A total of 119 cerebrospinal fluid samples were collected from 28 severe traumatic brain injury patients. Samples were retrieved at 12, 24, 48, 72 hours and before external ventricular drain removal. Fifteen control samples were obtained from patients with normal pressure hydrocephalus. Sulfonylurea receptor- 1 was quantified by enzyme-linked immunosorbent assay. Outcomes included CT edema, intracranial pressure measurements, therapies targeting edema, and 3-month Glasgow Outcome Scale score. MAIN RESULTS: Sulfonylurea receptor-1 was present in all severe traumatic brain injury patients (mean = 3.54 ± 3.39 ng/mL, peak = 7.13 ± 6.09 ng/mL) but undetectable in all controls (p < 0.001). Mean and peak sulfonylurea receptor-1 was higher in patients with CT edema (4.96 ± 1.13 ng/mL vs 2.10 ± 0.34 ng/mL; p = 0.023). There was a temporal delay between peak sulfonylurea receptor-1 and peak intracranial pressure in 91.7% of patients with intracranial hypertension. There was no association between mean/peak sulfonylurea receptor-1 and mean/peak intracranial pressure, proportion of intracranial pressure greater than 20 mm Hg, use of edema-directed therapies, decompressive craniotomy, or 3-month Glasgow Outcome Scale. However, decreasing sulfonylurea receptor-1 trajectories between 48 and 72 hours were significantly associated with improved cerebral edema and clinical outcome. Area under the multivariate model receiver operating characteristic curve was 0.881. CONCLUSIONS: This is the first report quantifying human cerebrospinal fluid sulfonylurea receptor-1. Sulfonylurea receptor-1 was detected in severe traumatic brain injury, absent in controls, correlated with CT-edema and preceded peak intracranial pressure. Sulfonylurea receptor-1 trajectories between 48 and 72 hours were associated with outcome. Because a therapy inhibiting sulfonylurea receptor-1 is available, assessing cerebrospinal fluid sulfonylurea receptor-1 in larger studies is warranted to evaluate our exploratory findings regarding its diagnostic, and monitoring utility, as well as its potential to guide targeted therapies in traumatic brain injury and other diseases involving cerebral edema.