Golf cart injuries have similar severity to all-terrain vehicle injuries in children: a multicenter comparison over a 5-year period

Background

Golf carts (GCs) and all-terrain vehicles (ATVs) are popular forms of personal transport. Although ATVs are considered adventurous and dangerous, GCs are perceived to be safer. Anecdotal experience suggests increasing numbers of both GC and ATV injuries, as well as high severity of GC injuries in children. This multicenter study examined GC and ATV injuries and compared their injury patterns, resource utilization, and outcomes.

Methods

Pediatric trauma centers in Florida submitted trauma registry patients age <16 years from January 2016 to June 2021. Patients with GC or ATV mechanisms were identified. Temporal trends were evaluated. Injury patterns, resource utilization, and outcomes for GCs and ATVs were compared. Intensive care unit admission and immediate surgery needs were compared using multivariable logistic regression.

Results

We identified 179 GC and 496 ATV injuries from 10 trauma centers. GC and ATV injuries both increased during the study period (R2 0.4286, 0.5946, respectively). GC patients were younger (median 11 vs 12 years, p=0.003) and had more intracranial injuries (34% vs 19%, p<0.0001). Overall Injury Severity Score (5 vs 5, p=0.27), intensive care unit (ICU) admission (20% vs 16%, p=0.24), immediate surgery (11% vs 11%, p=0.96), and mortality (1.7% vs 1.4%, p=0.72) were similar for GCs and ATVs, respectively. The risk of ICU admission (OR 1.19, 95% CI 0.74 to 1.93, p=0.47) and immediate surgery (OR 1.04, 95% CI 0.58 to 1.84, p=0.90) remained similar on multivariable logistic regression.

Conclusions

During the study period, GC and ATV injuries increased. Despite their innocuous perception, GCs had a similar injury burden to ATVs. Heightened safety measures for GCs should be considered.

Level of evidence

III, prognostic/epidemiological.

Transcriptomic Differences in Peripheral Monocyte Populations in Septic Patients Based on Outcome

ABSTRACT

Post-sepsis early mortality is being replaced by survivors who experience either a rapid recovery and favorable hospital discharge or the development of chronic critical illness (CCI) with suboptimal outcomes. The underlying immunological response that determines these clinical trajectories remains poorly defined at the transcriptomic level. As classical and non-classical monocytes are key leukocytes in both the innate and adaptive immune systems, we sought to delineate the transcriptomic response of these cell types. Using single-cell RNA sequencing and pathway analyses, we identified gene expression patterns between these two groups that are consistent with differences in TNFα production based on clinical outcome. This may provide therapeutic targets for those at risk for CCI in order to improve their phenotype/endotype, morbidity, and long-term mortality.

The post-septic peripheral myeloid compartment reveals unexpected diversity in myeloid-derived suppressor cells

Introduction

Sepsis engenders distinct host immunologic changes that include the expansion of myeloid-derived suppressor cells (MDSCs). These cells play a physiologic role in tempering acute inflammatory responses but can persist in patients who develop chronic critical illness.

Methods

Cellular Indexing of Transcriptomes and Epitopes by Sequencing and transcriptomic analysis are used to describe MDSC subpopulations based on differential gene expression, RNA velocities, and biologic process clustering.

Results

We identify a unique lineage and differentiation pathway for MDSCs after sepsis and describe a novel MDSC subpopulation. Additionally, we report that the heterogeneous response of the myeloid compartment of blood to sepsis is dependent on clinical outcome.

Discussion

The origins and lineage of these MDSC subpopulations were previously assumed to be discrete and unidirectional; however, these cells exhibit a dynamic phenotype with considerable plasticity.

Social determinants of health in pediatric trauma: Associations with injury mechanisms and outcomes in the context of the COVID-19 pandemic

BACKGROUND

Relationships between social determinants of health and pediatric trauma mechanisms and outcomes are unclear in context of COVID-19.

METHODS

Children <16 years old injured between 2016 and 2021 from ten pediatric trauma centers in Florida were included. Patients were stratified by high vs. low Social Vulnerability Index (SVI). Injury mechanisms studied were child abuse, ATV/golf carts, and firearms. Mechanism incidence trends and mortality were evaluated by interrupted time series and multivariable logistic regression.

RESULTS

Of 19,319 children, 68% and 32% had high and low SVI, respectively. Child abuse increased across SVI strata and did not change with COVID. ATV/golf cart injuries increased after COVID among children with low SVI. Firearm injuries increased after COVID among children with high SVI. Mortality was predicted by injury mechanism, but was not independently associated with SVI, race, or COVID.

CONCLUSION

Social vulnerability influences pediatric trauma mechanisms and COVID effects. Child abuse and firearm injuries should be targeted for prevention.

Monocyte anisocytosis corresponds with increasing severity of COVID-19 in children

Introduction

Although SARS-CoV-2 infection can lead to severe COVID-19 in children, the role of biomarkers for assessing the risk of progression to severe disease is not well established in the pediatric population. Given the differences in monocyte signatures associated with worsening COVID-19 in adults, we aimed to determine whether monocyte anisocytosis early in the infectious course would correspond with increasing severity of COVID-19 in children.

Methods

We performed a multicenter retrospective study of 215 children with SARS-CoV-2 infection, Multisystem Inflammatory Syndrome in Children (MIS-C), convalescent COVID-19, and healthy age-matched controls to determine whether monocyte anisocytosis, quantified by monocyte distribution width (MDW) on complete blood count, was associated with increasing severity of COVID-19. We performed exploratory analyses to identify other hematologic parameters in the inflammatory signature of pediatric SARS-CoV-2 infection and determine the most effective combination of markers for assessing COVID-19 severity in children.

Results

Monocyte anisocytosis increases with COVID-19 severity and need for hospitalization. Although other inflammatory markers such as lymphocyte count, neutrophil/lymphocyte ratio, C-reactive protein, and cytokines correlate with disease severity, these parameters were not as sensitive as MDW for identifying severe disease in children. An MDW threshold of 23 offers a sensitive marker for severe pediatric COVID-19, with improved accuracy when assessed in combination with other hematologic parameters.

Conclusion

Monocyte anisocytosis corresponds with shifting hematologic profiles and inflammatory markers in children with COVID-19, and MDW serves as a clinically accessible biomarker for severe COVID-19 in children.

Exploring Limited English Proficiency in the Clinical Outcomes of Pediatric Burn Patients

INTRODUCTION

Limited English proficiency (LEP) is linked to lower health care access and worse clinical outcomes. This study aims to explore the potential role of LEP on clinical outcomes of pediatric burn patients.

METHODS

We conducted a single-institution retrospective study of burn patients presenting at a tertiary pediatric burn referral program between January 2016 and December 2020. Patient demographics, burn mechanism, severity, interventions, and primary patient language were abstracted from the electronic health record. Clinical outcomes (length of stay [LOS], clinic follow-up, and 30-day readmission) of patients with LEP were compared to patients with English as primary language (EPL).

RESULTS

Thirty-five (4.2%) patients with LEP were identified of 840 total patients. On univariate analysis, there was no difference in mean total body surface area (6.5% versus 6.1%), report of physical abuse (2.9% versus 8.9%), or need for grafting (14.3% versus 15.0%) comparing patients with LEP to those with EPL. Patients with LEP were more likely to have a scald burn (68.6% versus 48.9%, P = 0.025) and less likely to have a flame/fire burn (20.0% versus 37.6%, P = 0.047). On multivariate analysis, there was no difference between patients with LEP compared to patients with EPL for LOS (2.9 versus 3.5 d), 30-day readmissions (5.6% versus 5.7%), or clinic follow-up (80.6% versus 75.0%). In patients with >10% total body surface area, patients with LEP had a longer emergency department LOS (277 min versus 145 min, P = 0.06) but no difference in outcome measures.

CONCLUSIONS

Pediatric patients with LEP were not found to have worse burn outcomes compared to EPL patients in our patient sample. However, a true association is difficult to determine given the small sample size of LEP patients and the potential underestimation of language discordancy as recorded in the electronic medical record. Further research is needed to better explore the role of primary language and health communication as a social determinant of health in pediatric burn patients.

VARIABLES INFLUENCING THE DIFFERENTIAL HOST RESPONSE TO BURNS IN PEDIATRIC AND ADULT PATIENTS

ABSTRACT

Burn injury is a significant source of morbidity and mortality in the pediatric population. Although 40,000 pediatric patients in the United States are admitted to the hospital with burn wounds annually, significant differences exist in the management and treatment of these patients, even among highly specialized burn centers. Some aspects of pediatric burn research, such as metabolic changes and nutritional support after burn injury, have been studied extensively; however, in many aspects of burn care, pediatric research lags behind the study of adult populations. This review compares and contrasts a wide array of physiologic and immune responses between children and adults after burn injury. Such a review elucidates where robust research has been conducted, where adult research is applicable to pediatric patients, and where additional pediatric burn research needs to be conducted.

TRAINED IMMUNITY: A POTENTIAL APPROACH FOR IMPROVING HOST IMMUNITY IN NEONATAL SEPSIS

ABSTRACT

Sepsis, a dysregulated host immune response to infection, is one of the leading causes of neonatal mortality worldwide. Improved understanding of the perinatal immune system is critical to improve therapies to both term and preterm neonates at increased risk of sepsis. Our narrative outlines the known and unknown aspects of the human immune system through both the immune tolerant in utero period and the rapidly changing antigen-rich period after birth. We will highlight the key differences in innate and adaptive immunity noted through these developmental stages and how the unique immune phenotype in early life contributes to the elevated risk of overwhelming infection and dysregulated immune responses to infection upon exposure to external antigens shortly after birth. Given an initial dependence on neonatal innate immune host responses, we will discuss the concept of innate immune memory, or "trained immunity," and describe several potential immune modulators, which show promise in altering the dysregulated immune response in newborns and improving resilience to sepsis.

Social determinants of health in pediatric scald burns: Is food access an issue?

BACKGROUND

Burn injury risk, severity, and outcomes have been associated with socioeconomic status. Limited data exist to evaluate health access-related influences at a structural population level. This study evaluated factors at the Census-tract level, specifically evaluating food access and social vulnerability in pediatric scald burns.

METHODS

A single-institution retrospective review using the trauma registry and electronic medical record was conducted of pediatric burns between 2016 and 2020. Home address was coded to the Census-tract level and bulk analyzed. Socioeconomic metrics of the home environment were evaluated from publicly available databases, the United States Food and Drug Administration Food Access Research Atlas, and the Centers for Disease Control's Social Vulnerability Index.

RESULTS

There were 840 patients that met inclusion criteria (49.8% scald, N = 418). The mean total body surface area for scalds was 6.6% with an age of 10.2 years; 76% (n = 317) of scalds had Medicaid, and 15% (n = 63) were due to hot noodles. Scalds occurred more in females (45.7%, N = 191 vs 28.0%, N = 118; P < .0001), non-White race (62.7%, N = 262 vs 29.1%, N = 123; P < .0001), and low-income and low-food access populations (39.8%, N = 147 vs 30.4%, N = 116; P = .007). Low-food access Black populations showed increased scald injury (18% [interquartile range 6-35] vs 10% [interquartile range 4-25]), whereas all other populations showed no association. The patients with scalds had a higher overall social vulnerability index (0.67 vs 0.62, P = .008).

CONCLUSION

Often related to poverty, health access, and health equity, population-level social determinants of health like social vulnerability and food access have significant impact on health care and should influence health outreach and systems improvement.

Heterogeneity in the evaluation of suspected MIS-C: a cross-sectional vignette-based survey

Background and Objectives

Multisystem Inflammatory Syndrome in Children (MIS-C) is an emerging complication of COVID-19 which lacks a definitive diagnostic test and evidence-based guidelines for workup. We sought to assess practitioners' preferences when initiating a workup for pediatric patients presenting with symptoms concerning for MIS-C.

Methods

In a cross-sectional vignette-based survey, providers were presented with clinical vignettes of a patient presenting with 24 h of fever from a community with high rates of COVID-19. Respondents were asked about their general practices in pursuing a workup for potential MIS-C including testing obtained, criteria for diagnosis, and timing to confirm or rule out the diagnosis.

Results

Most of the 174 respondents were physicians from the United States at academic medical centers. The majority of providers would not initiate MIS-C workup for fever and non-specific symptoms unless the fever lasted more than 72 h. Skin rash, abdominal pain, and shortness of breath were symptoms that raised greatest concern for MIS-C. Most providers would obtain COVID-19 PCR or antigen testing, plus blood work, in the initial workup. The list of laboratory studies providers would obtain is extensive. Providers primarily rely on cardiac involvement to confirm a MIS-C diagnosis, and establishing a diagnosis takes 24–48 h.

Conclusions

Significant heterogeneity exists amongst providers as to when to initiate the MIS-C workup, the order and content of the workup, and how to definitively diagnose MIS-C. A diagnostic test with high sensitivity and specificity for MIS-C and refined evidence-based guidelines are needed to expedite diagnosis and treatment.

Monocyte anisocytosis increases during multisystem inflammatory syndrome in children with cardiovascular complications

Background

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening complication that can develop weeks to months after an initial SARS-CoV-2 infection. A complex, time-consuming laboratory evaluation is currently required to distinguish MIS-C from other illnesses. New assays are urgently needed early in the evaluation process to expedite MIS-C workup and initiate treatment when appropriate. This study aimed to measure the performance of a monocyte anisocytosis index, obtained on routine complete blood count (CBC), to rapidly identify subjects with MIS-C at risk for cardiac complications.

Methods

We measured monocyte anisocytosis, quantified by monocyte distribution width (MDW), in blood samples collected from children who sought medical care in a single medical center from April 2020 to October 2020 (discovery cohort). After identifying an effective MDW threshold associated with MIS-C, we tested the utility of MDW as a tier 1 assay for MIS-C at multiple institutions from October 2020 to October 2021 (validation cohort). The main outcome was the early screening of MIS-C, with a focus on children with MIS-C who displayed cardiac complications. The screening accuracy of MDW was compared to tier 1 routine laboratory tests recommended for evaluating a child for MIS-C.

Results

We enrolled 765 children and collected 846 blood samples for analysis. In the discovery cohort, monocyte anisocytosis, quantified as an MDW threshold of 24.0, had 100% sensitivity (95% CI 78–100%) and 80% specificity (95% CI 69–88%) for identifying MIS-C. In the validation cohort, an initial MDW greater than 24.0 maintained a 100% sensitivity (95% CI 80–100%) and monocyte anisocytosis displayed a diagnostic accuracy greater that other clinically available hematologic parameters. Monocyte anisocytosis decreased with disease resolution to values equivalent to those of healthy controls.

Conclusions

Monocyte anisocytosis detected by CBC early in the clinical workup improves the identification of children with MIS-C with cardiac complications, thereby creating opportunities for improving current practice guidelines.

T-Cell Activation and LPS: A Dangerous Duo for Organ Dysfunction

Lipopolysaccharide (LPS), one of the main components of cell membranes in gram-negative bacteria, is commonly used to promote inflammation-induced organ dysfunction. In the TLR4/LPS pathway, LPS binding protein and CD14 enable lipid A of LPS to be recognized by the TLR4-MD2 receptor complex. The intracellular domain of the TLR4/LPS complex stimulates MyD88-dependent/independent and TRIF-dependent pathways, which in turn activate NF-B and IRF3, leading to subsequent production of pro-inflammatory mediators. LPS has been demonstrated to induce microcirculatory disturbances via promotion of leukocyte adhesion to the vascular endothelium and the release of reactive oxygen species (ROS), damaging the vessels and causing vascular dysfunction. Thus, LPS is frequently used as a systemic model of inflammation as LPS administration increases circulating pro-inflammatory mediators, which triggers leukocyte adhesion and leads to multi-organ failure and death.

49 Bromelain Based Enzymatic Debridement of Pediatric Deep Burns: Top Line Results of a Multicenter RCT

Introduction

Bromelain based debridement (BBD) of deep burns with a concentrate of proteolytic enzymes enriched in Bromelain is approved for use in adults in several regions worldwide. Children are a large part of the patient population in many burn centers around the world. Clinical trial experience and off label reports point to BBD safety and efficacy in children as well. The aim of this study was to further assess the safety and efficacy of BBD in children, in efforts to support regulatory approval for the use of BBD in children.

Methods

One hundred and forty five children aged 0-18 years old suffering from deep thermal burns between 1-30% TBSA were enrolled in a multicenter, multinational, open label, randomized, controlled phase III study. Seventy two children were randomized to eschar removal with BBD and 73 children to standard of care (SOC) surgical and/or non-surgical eschar removal methods, at the investigators' discretion. Patients who did not achieve complete eschar removal after BBD application were rescued with SOC eschar removal methods. Wound care after achieving complete eschar removal was according to routine methods, at the investigators' discretion. Patients are currently in stages of long term follow-up, planned for a duration of &gt;2 years. This abstract reports the top line results of the study including the first year of follow-up.

Results

Baseline characteristics were similar between the arms. The median age was 3.4 years in the BBD arm and 3.9 years in the SOC arm. The average burn area was 7.0±4.9 %TBSA in the BBD arm and 6.2±4.8 %TBSA in the SOC arm. The study met all 3 primary endpoints: Median time to complete eschar removal was 1 day for BBD and 6 days for SOC (p&lt; 0.001), the percent wound area excised in order to complete eschar removal was 1.5% for BBD and 48% for SOC (p&lt; 0.0001), and the MVSS scores at 12 months were 3.83 for BBD and 4.86 for SOC (non-inferiority endpoint). Secondary endpoints demonstrated 8.3% incidence of surgical excision to complete eschar removal for BBD and 64.4% for SOC (p&lt; 0.0001), mean eschar removal associated blood loss of 32±284ml for BBD and 202±409 for SOC (NS), a 25.9% incidence of autografting in deep partial thickness wounds for BBD and 37.7% for SOC (p=0.054), and a mean percent area of deep partial thickness wound autografting of 15.9±38.6 for BBD and 22.8±43.7 for SOC (NS). Safety endpoints demonstrated a non-inferior time to complete wound closure (median 32 days for BBD, 34 days for SOC) and no significant safety issues were demonstrated during the study.

Conclusions

BBD was shown to be a safe and effective debridement agent in pediatric burns.

Medical Student Career Choice: Who Is the Influencer?

BACKGROUND

While many factors influence medical student career choice, interactions with attending and resident physicians during clinical rotations are particularly important. To evaluate the influence of attending and resident physicians on medical students' career choices, particularly for those pursuing surgical careers, we quantified their respective influence in the context of other known influences.

METHODS

Rising fourth-year medical students and new graduates were given an IRB-exempt, 14-item online survey. Descriptive statistics were performed on the demographic information. Chi-square analysis was used, as were Kruskal-Wallis and Mann-Whitney analyses on the Likert responses (α = 0.05).

RESULTS

Survey response was 24%. Students pursuing general surgery rated residents greater than or equal to attendings on 7 of 8 key mentoring characteristics. Of students choosing a different specialty than the one they intended to pursue upon entering medical school, the influence of residents was cited by 100% of the students pursuing general surgery, compared to 59% of the entire cohort. Identification of a role model and perceived personality fit were significantly more important than other factors (P < 0.0001). Students pursuing general surgery rated the importance of identifying a role model and perceived personality fit greater than their peers.

CONCLUSIONS

Residents have greater influences on medical students' career choice compared to attendings. Students pursuing a surgical specialty, particularly general surgery, considered the influence of role models and perceived personality fit to be the most important factors in their specialty decision. These findings provide valuable insights to improve student experiences and career recruitment in surgical specialties, particularly general surgery.

Prehospital personnel discretion pediatric trauma team activations: Too much of a good thing?

PURPOSE

Trauma team activation is essential to provide rapid assessment of injured patients, however excessive utilization can overburden systems. We aimed to identify predictors of over triage and evaluate impact of prehospital personal discretion trauma activations on the over triage rate.

METHODS

Retrospective comparative study of pediatric trauma patients (<18 years) evaluated after activation of the trauma team to those evaluated as a trauma consult treated between 2010 and 2013. Cohort matching of trauma activated and consult patients was done on the basis of patients' age and ISS.

RESULTS

1363 patients including 359 trauma team activations were evaluated. Median age was 6 years, Injury Severity Score (ISS) 4, 116 (8.5%) required operative intervention and 20 (1.4%) died. Matched analysis using age and ISS showed trauma activated patients were more likely to have penetrating MOI (4.7% vs.1.7%; p = 0.03) and need ICU admission(32.9% vs.16.7%; p = 0.0001). State of Florida discrete criteria based trauma activated patients when compared to paramedic discretion activations had a higher ISS (9 vs.5; p = 0.014), need for ICU admission (36.5% vs.20.4%; p = 0.004), ICU LOS(2 vs.0 days; p = 0.02), hospital LOS(2 vs.2 days; p = 0.014) and higher likelihood of death(4.9% vs.0%;p = 0.0001). Moreover, paramedic discretion trauma activated patients were similar to trauma consult patients in terms of ISS score(p = 0.86), need for ICU admission(p = 0.86), operative intervention(p = 0.86), death(p = 0.86) and hospital LOS(p = 0.86), with a considerably higher cost of care(p = 0.0002).

CONCLUSION

Discrete criteria-based trauma team activations appear to more reliably identify patients likely to benefit from initial multidisciplinary management.

Analysis of Outcomes in Adolescents and Young Adults With Pilonidal Disease

Purpose: Numerous definitive surgical techniques exist for the treatment of pilonidal disease with varied recurrence rates and wound complications. Due to the wide array of techniques and lack of consensus on the best approach, we proposed to study our experience treating pilonidal disease in adolescents and young adults.

Methods: A retrospective analysis was conducted of patients 10–24 years old treated at a tertiary medical center from 2011 to 2016. Data including demographics, management, and outcomes were collected and analyzed. Primary outcome was recurrence of disease.

Results: One hundred and thirty three patients with pilonidal disease underwent operative management. Fifty one percent underwent primary closure and 49% healed by secondary intention with no significant difference in recurrence rates (primary 18%, secondary 11%; p = 0.3245). Secondary healing patients had significantly lower wound complication rates (primary 51%, secondary 23%; p = 0.0012). After accounting for sex, race, weight, and operative technique, age was predictive of disease recurrence with an adjusted odds ratio (OR) of 0.706 (0.560–0.888; p = 0.003). Age and sex were both predictive of wound complications. Older patients had decreased risk of wound complication (adjusted OR 0.806, 95% CI 0.684–0.951; p = 0.0105), and male patients had increased risk of wound complication (adjusted OR 2.902, 95% CI 1.001–8.409; p = 0.0497).

Conclusion: In summary, there is no significant difference in the recurrence rates between operative techniques for pilonidal disease. Older patients have decreased risk of recurrence following intervention. Wound complication rates are lower in patients undergoing secondary healing, though this may be better explained by differences in age and sex. Additional research investigating newer, minimally-invasive techniques needs to be pursued.

Immunological Endotyping of Chronic Critical Illness After Severe Sepsis

Improved management of severe sepsis has been one of the major health care accomplishments of the last two decades. Due to enhanced recognition and improved management of severe sepsis, in-hospital mortality has been reduced by up to 40%. With that good news, a new syndrome has unfortunately replaced in-hospital multi-organ failure and death. This syndrome of chronic critical illness (CCI) includes sepsis patients who survive the early "cytokine or genomic storm," but fail to fully recover, and progress into a persistent state of manageable organ injury requiring prolonged intensive care. These patients are commonly discharged to long-term care facilities where sepsis recidivism is high. As many as 33% of sepsis survivors develop CCI. CCI is the result, at least in part, of a maladaptive host response to chronic pattern-recognition receptor (PRR)-mediated processes. This maladaptive response results in dysregulated myelopoiesis, chronic inflammation, T-cell atrophy, T-cell exhaustion, and the expansion of suppressor cell functions. We have defined this panoply of host responses as a persistent inflammatory, immune suppressive and protein catabolic syndrome (PICS). Why is this important? We propose that PICS in survivors of critical illness is its own common, unique immunological endotype driven by the constant release of organ injury-associated, endogenous alarmins, and microbial products from secondary infections. While this syndrome can develop as a result of a diverse set of pathologies, it represents a shared outcome with a unique underlying pathobiological mechanism. Despite being a common outcome, there are no therapeutic interventions other than supportive therapies for this common disorder. Only through an improved understanding of the immunological endotype of PICS can rational therapeutic interventions be designed.

Aluminum Adjuvant Improves Survival Via NLRP3 Inflammasome and Myeloid Non-Granulocytic Cells in a Murine Model of Neonatal Sepsis

ABSTRACT

Neonatal sepsis leads to significant morbidity and mortality with the highest risk of death occurring in preterm (<37 weeks) and low birth weight (<2,500 g) infants. The neonatal immune system is developmentally immature with well-described defects in innate and adaptive immune responses. Immune adjuvants used to enhance the vaccine response have emerged as potential therapeutic options, stimulating non-specific immunity and preventing sepsis mortality. Aluminum salts ("alum") have been used as immune adjuvants for over a century, but their mechanism of action remains poorly understood. This study aims to identify potential mechanisms by which pretreatment with alum induces host protective immunity to polymicrobial sepsis in neonatal mice. Utilizing genetic and cell-depletion studies, we demonstrate here that the prophylactic administration of aluminum adjuvants in neonatal mice improves sepsis survival via activation of the nucleotide oligomerization domain-like receptor family, pyrin-domain-containing 3 inflammasome and dendritic cell activation. Furthermore, this beneficial effect is dependent on myeloid, non-granulocytic Gr1-positive cells, and MyD88-signaling pathway activation. These findings suggest a promising therapeutic role for aluminum-based vaccine adjuvants to prevent development of neonatal sepsis and improve mortality in this highly vulnerable population.

Long-term outcomes of antegrade continence enema in children with chronic encopresis and incontinence: what is the optimal flush to use?

PURPOSE

Severe constipation and encopresis are significant problems in the pediatric population. Medical management succeeds in 50-70%; however, surgical considerations are necessary for the remainder such as the antegrade continence enema (ACE). The purpose of this study is to assess the long-term outcomes following the ACE procedure.

METHODS

All patients undergoing an ACE over a 14-year period were included. Data on clinical conditions, treatments, and outcomes were collected. A successful outcome was defined as remaining clean with ≤ 1 accident per week. Comparative data were analyzed using the Fisher's exact test, Mann-Whitney U test, or Student's t test.

RESULTS

There were 42 ACE patients, and overall, 79% had improvement in their bowel regimens. Encopresis rates decreased from 79 to 5% (P < 0.001). Admissions for cleanouts decreased from 52 to 19% (P = 0.003). All cases of Hirschsprung's, functional constipation and spina bifida were successful. Rates of success varied for other diseases such as slow-transit constipation (60%) and cerebral palsy (33%). A majority (85%) required a change in the enema composition for improvement.

CONCLUSION

In our study, ACE reduced soiling, constipation, and need for fecal disimpaction. Higher volume saline flushes used once a day was the optimal solution and most preferred option.

LEVEL OF EVIDENCE

Level 4 (retrospective case series or cohort).

Inguinal hernias in premature neonates: exploring optimal timing for repair

PURPOSE

Inguinal hernias have been reported in as many as 10-30% premature neonates, making inguinal herniorrhaphy (IHR) one of the most commonly performed surgical procedures. The timing of surgery remains controversial. The purpose of this report is to compare outcomes of IHR while in the NICU (inpatient) versus repair following discharge (outpatient) to determine optimal timing.

METHODS

Premature neonates having undergone IHR over a 5-year period were identified and a retrospective case cohort analysis was performed.

RESULTS

263 patients underwent IHR during the 5-year study period with 115 (43.7%) having surgical repair inpatient (IP; prior to discharge) and 148 having outpatient herniorrhaphy (OP). Patients with IHR performed IP had significantly lower birth weight (p < 0.001), gestational age (p < 0.001), longer duration of surgery (p = 0.01) and were more likely to have post-operative ventilator dependence following repair; however, there were no differences in the rate of recurrence (p = 0.44) and incarceration (p = 0.45).

CONCLUSION

Our study demonstrated no significant differences in the rates of incarceration or recurrence, following in- or out-patient IHR. These findings suggest that IHR can potentially be offered as an outpatient procedure following hospital discharge in appropriate patients. The optimal timing of IHR in premature infants remains elusive and will likely require additional multicenter investigation.

Sepsis is associated with reduced spontaneous neutrophil migration velocity in human adults

Sepsis is a common and deadly complication among trauma and surgical patients. Neutrophils must mobilize to the site of infection to initiate an immediate immune response. To quantify the velocity of spontaneous migrating blood neutrophils, we utilized novel microfluidic approaches on whole blood samples from septic and healthy individuals. A prospective study at a level 1 trauma and tertiary care center was performed with peripheral blood samples collected at <12 hours, 4 days, and/or 14 days relative to study initiation. Blood samples were also collected from healthy subjects. Ex vivo spontaneous neutrophil migration was measured on 2 μl of whole blood using microfluidic devices and time-lapse imaging. For each sample, individual neutrophils were tracked to calculate mean instantaneous velocity. Forty blood samples were collected from 33 patients with sepsis, and 15 blood samples were collected from age- and gender-matched healthy, control subjects. Average age was 61 years for septic patients with a male predominance (67%). Overall, average spontaneous neutrophil migration velocity in septic samples was 16.9 μm/min, significantly lower than controls samples at 21.1 μm/min (p = 0.0135). Neutrophil velocity was reduced the greatest at <12 hours after sepsis (14.5 μm/min). Regression analysis demonstrated a significant, positive correlation between neutrophil velocity and days after sepsis (p = 0.0059). There was no significant association between neutrophil velocity and age, gender, APACHE II score, SOFA score, sepsis severity, total white blood cell count, or percentage of neutrophils. Circulating levels of the cytokines IL-6, IL-8, IL-10, MCP-1, IP-10, and TNF were additionally measured using bead-based multiplex assay and found to peak at <12 hours and be significantly increased in patients with sepsis at all three time points (<12 hours, 4 days, and 14 days after sepsis) compared to healthy subjects. In conclusion, these findings may demonstrate an impaired ability of neutrophils to respond to sites of infection during the proinflammatory phase of sepsis.

Initial primary spontaneous pneumothorax in children and adolescents: Operate or wait?

PURPOSE

The management of primary spontaneous pneumothorax (PSP) in the pediatric population is not standardized. The purpose of this study was to understand the management options for a first episode of PSP in children and adolescents, and their associated outcomes.

METHODS

A retrospective study was conducted for patients 5-20 years old with a diagnosis of PSP at a large academic children's hospital between 2002 and 2014. Patient data were reviewed for each case. Management and outcomes were analyzed and compared between groups.

RESULTS

Eighty patients met all inclusion criteria. Overall recurrence rate was 40% with 86% occurring within 12 months of the initial PSP. Patients with recurrent PSP were significantly taller. Size of pneumothorax based on initial chest x-ray was comparable between recurrent and nonrecurrent groups. A negative CT scan for subpleural blebs did not predict recurrence. Patients undergoing thoracoscopic blebectomy and mechanical pleurodesis at initial presentation had significantly lower recurrence rate compared to patients who underwent nonoperative management (operative group 14%, nonoperative group 45%; p=0.0373).

CONCLUSIONS

Recurrence following nonoperative management was high with the majority occurring within a year and requiring readmission. These findings support offering surgery to families as a potential initial management option.

LEVEL OF EVIDENCE

3b/4 - retrospective series or case control study, single institution, very limited population.

Review: The Perioperative Use of Thromboelastography for Liver Transplant Patients

Thromboelastography (TEG) is a viscoelastic test that allows rapid evaluation of clot formation and fibrinolysis from a sample of whole blood. TEG is increasingly utilized to guide blood product resuscitation in surgical patients and transfusions for liver transplant patients. Patients with severe liver failure have significant derangement of their clotting function due to impaired production of procoagulant and anticoagulant factors. Traditional coagulation studies are limited by the short time needed for the result and provide little information about the dynamics and strength of clot formation. In addition, traditional coagulation studies do not correlate well with bleeding episodes and may lead to over-transfusion of various blood products. Evidence is less robust regarding the use of TEG for transfusion management decisions in severe liver failure patients awaiting, undergoing, or immediately after liver transplant surgery. However, the available evidence suggests that systematic implementation of TEG rather than traditional coagulation studies results in the administration of fewer blood products without increased mortality or complications. The purpose of this study is to review the literature regarding the use of TEG in liver failure patients prior to liver transplant, intraoperatively, and postoperatively. Additional high-quality randomized controlled studies should be performed to evaluate the use of TEG to guide transfusion decisions, particularly in the postoperative period following liver transplantation.

Impact of toll-like receptor 4 stimulation on human neonatal neutrophil spontaneous migration, transcriptomics, and cytokine production

Neonates rely on their innate immune system, and neutrophils in particular, to recognize and combat life-threatening bacterial infections. Pretreatment with lipopolysaccharide (LPS), a toll-like receptor (TLR) 4 agonist, improves survival to polymicrobial sepsis in neonatal mice by enhancing neutrophil recruitment. To understand the response of human neonatal neutrophils to TLR4 stimulation, ex vivo spontaneous neutrophil migration, neutrophil transcriptomics, and cytokine production in the presence and absence of LPS were measured directly from whole blood of adults, term neonates, and preterm neonates. Spontaneous neutrophil migration was measured on novel microfluidic devices with time-lapse imaging for 10 h. Genome-wide neutrophil transcriptomics and plasma cytokine concentrations were also determined. Preterm neonates had significantly fewer spontaneously migrating neutrophils at baseline, and both term and preterm neonates had decreased neutrophil velocity, compared to adults. In the presence of LPS stimulation, the number of spontaneously migrating neutrophils was reduced in preterm neonates compared to term neonates and adults. Neutrophil velocity was not significantly different among groups with LPS stimulation. Preterm neonates upregulated expression of genes associated with the recruitment and response of neutrophils following LPS stimulation, but failed to upregulate the expression of genes associated with antimicrobial and antiviral responses. Plasma levels of IL-1β, IL-6, IL-8, MIP-1α, and TNF-α increased in response to LPS stimulation in all groups, but IL-10 was increased only in term and preterm neonates. In conclusion, age-specific changes in spontaneous neutrophil migration counts are not affected by LPS despite changes in gene expression and cytokine production.

KEY MESSAGES

Preterm neonates have reduced spontaneous neutrophil migration compared to term neonates and adults in the absence and presence of TLR4 stimulation. Preterm and term neonates have reduced neutrophil velocities compared to adults in the absence of TLR4 stimulation but no difference in the presence of TLR4 stimulation. Unique transcriptomic response to TLR4 stimulation is observed in neutrophils from preterm neonates, term neonates, and adults. TLR4 stimulation produces an age-specific cytokine response.

Delayed Healing Associated with Silver Sulfadiazine Use for Partial Thickness Scald Burns in Children

Burns are a leading cause of injury in children. Management principles vary widely, with no consensus about the best treatment. The purpose of this study was to compare outcomes of three different dressings for pediatric partial-thickness scald burns. A retrospective, single-center study was conducted for patients 0-16 years old with a diagnosis of acute partial-thickness scald burn between July 2007 and December 2012. Data regarding prehospital, inpatient, and outpatient course were collected. Cohort was stratified into topical antimicrobial (TA) ointment, silver sulfadiazine (SS), and biosynthetic dressing (BD) groups for analysis. The primary outcome of interest was time to full healing. One hundred and seventy-seven patients met all study criteria. Overall, mean total body surface area burned was 8.3 per cent. TA was used in 24 per cent cases, SS in 32 per cent, and BD in 44 per cent. The groups were comparable in terms of presenting burn characteristics and hospital course with the exception of the BD group being associated with greater extent of injury. Patients treated with SS had a significantly longer time to full healing and increased requirement of compression garments for scar therapy. Based on these data, the authors have amended their practice and presently use BD or TA dressings to improve healing.

Delayed Healing Associated with Silver Sulfadiazine Use for Partial Thickness Scald Burns in Children

Burns are a leading cause of injury in children. Management principles vary widely, with no consensus about the best treatment. The purpose of this study was to compare outcomes of three different dressings for pediatric partial-thickness scald burns. A retrospective, single-center study was conducted for patients 0–16 years old with a diagnosis of acute partial-thickness scald burn between July 2007 and December 2012. Data regarding prehospital, inpatient, and outpatient course were collected. Cohort was stratified into topical antimicrobial (TA) ointment, silver sulfadiazine (SS), and biosynthetic dressing (BD) groups for analysis. The primary outcome of interest was time to full healing. One hundred and seventy-seven patients met all study criteria. Overall, mean total body surface area burned was 8.3 per cent. TAwas used in 24 per cent cases, SS in 32 per cent, and BD in 44 per cent. The groups were comparable in terms of presenting burn characteristics and hospital course with the exception of the BD group being associated with greater extent of injury. Patients treated with SS had a significantly longer time to full healing and increased requirement of compression garments for scar therapy. Based on these data, the authors have amended their practice and presently use BD or TA dressings to improve healing.

Innate Immunity in the Persistent Inflammation, Immunosuppression, and Catabolism Syndrome and Its Implications for Therapy

Clinical and technological advances promoting early hemorrhage control and physiologic resuscitation as well as early diagnosis and optimal treatment of sepsis have significantly decreased in-hospital mortality for many critically ill patient populations. However, a substantial proportion of severe trauma and sepsis survivors will develop protracted organ dysfunction termed chronic critical illness (CCI), defined as ≥14 days requiring intensive care unit (ICU) resources with ongoing organ dysfunction. A subset of CCI patients will develop the persistent inflammation, immunosuppression, and catabolism syndrome (PICS), and these individuals are predisposed to a poor quality of life and indolent death. We propose that CCI and PICS after trauma or sepsis are the result of an inappropriate bone marrow response characterized by the generation of dysfunctional myeloid populations at the expense of lympho- and erythropoiesis. This review describes similarities among CCI/PICS phenotypes in sepsis, cancer, and aging and reviews the role of aberrant myelopoiesis in the pathophysiology of CCI and PICS. In addition, we characterize pathogen recognition, the interface between innate and adaptive immune systems, and therapeutic approaches including immune modulators, gut microbiota support, and nutritional and exercise therapy. Finally, we discuss the future of diagnostic and prognostic approaches guided by machine and deep-learning models trained and validated on big data to identify patients for whom these approaches will yield the greatest benefits. A deeper understanding of the pathophysiology of CCI and PICS and continued investigation into novel therapies harbor the potential to improve the current dismal long-term outcomes for critically ill post-injury and post-infection patients.

Neutrophil chemotaxis and transcriptomics in term and preterm neonates

Neutrophils play a crucial role in combating life-threatening bacterial infections in neonates. Previous studies investigating neonatal cell function have been limited because of restricted volume sampling. Here, using novel microfluidic approaches, we provide the first description of neutrophil chemotaxis and transcriptomics from whole blood of human term and preterm neonates, as well as young adults. Ex vivo percent cell migration, neutrophil velocity, and directionality to N-formylmethionyl-leucyl-phenylalanine were measured from whole blood using time-lapse imaging of microfluidic chemotaxis. Genome-wide expression was also evaluated in CD66b⁺ cells using microfluidic capture devices. Neutrophils from preterm neonates migrated in fewer numbers compared to term neonates (preterm 12.3%, term 30.5%, P = 0.008) and at a reduced velocity compared to young adults (preterm 10.1 μm/min, adult 12.7 μm/min, P = 0.003). Despite fewer neutrophils migrating at slower velocities, neutrophil directionality from preterm neonates was comparable to adults and term neonates. 3607 genes were differentially expressed among the 3 groups (P < 0.001). Differences in gene expression between neutrophils from preterm and term neonates were consistent with reduced pathogen recognition and antimicrobial activity but not neutrophil migration, by preterm neonates. In summary, preterm neonates have significant disturbances in neutrophil chemotaxis compared to term neonates and adults, and these differences in phenotype appear at the transcriptional level to target inflammatory pathways in general, rather than in neutrophil migration and chemotaxis.

Adjuvant pretreatment with alum protects neonatal mice in sepsis through myeloid cell activation

The high mortality in neonatal sepsis has been related to both quantitative and qualitative differences in host protective immunity. Pretreatment strategies to prevent sepsis have received inadequate consideration, especially in the premature neonate, where outcomes from sepsis are so dismal. Aluminium salts-based adjuvants (alum) are used currently in many paediatric vaccines, but their use as an innate immune stimulant alone has not been well studied. We asked whether pretreatment with alum adjuvant alone could improve outcome and host innate immunity in neonatal mice given polymicrobial sepsis. Subcutaneous alum pretreatment improves survival to polymicrobial sepsis in both wild-type and T and B cell-deficient neonatal mice, but not in caspase-1/11 null mice. Moreover, alum increases peritoneal macrophage and neutrophil phagocytosis, and decreases bacterial colonization in the peritoneum. Bone marrow-derived neutrophils from alum-pretreated neonates produce more neutrophil extracellular traps (NETs) and exhibit increased expression of neutrophil elastase (NE) after in-vitro stimulation with phorbol esters. In addition, alum pretreatment increases bone marrow and splenic haematopoietic stem cell expansion following sepsis. Pretreatment of neonatal mice with an alum-based adjuvant can stimulate multiple innate immune cell functions and improve survival. These novel findings suggest a therapeutic pathway for the use of existing alum-based adjuvants for preventing sepsis in premature infants.

Microbial recognition and danger signals in sepsis and trauma

Early host recognition of microbial invasion or damaged host tissues provides an effective warning system by which protective immune and inflammatory processes are initiated. Host tissues responsible for continuous sampling of their local environment employ cell surface and cytosolic pattern recognition receptors (PRRs) that provide redundant and overlapping identification of both microbial and host alarmins. Microbial products containing pathogen-associated molecular patterns (PAMPs), as well as damage-associated molecular patterns (DAMPs) serve as principle ligands for recognition by these PRRs. It is this interaction which plays both an essential survival role in response to infection and injury, as well as the pathologic role in tissue and organ injury associated with severe sepsis and trauma. Elucidating the interaction between ligands and their respective PRRs can provide both a better understanding of the host response, as well as a rational basis for therapeutic intervention. This article is part of a Special Issue entitled: Immune and Metabolic Alterations in Trauma and Sepsis edited by Dr. Raghavan Raju.

Impact of Early-Life Exposures to Infections, Antibiotics, and Vaccines on Perinatal and Long-term Health and Disease

Essentially, all neonates are exposed to infections, antibiotics, or vaccines early in their lives. This is especially true for those neonates born underweight or premature. In contrast to septic adults and children who are at an increased risk for subsequent infections, exposure to infection during the neonatal period is not associated with an increased risk of subsequent infection and may be paradoxically associated with reductions in late-onset sepsis (LOS) in the most premature infants. Perinatal inflammation is also associated with a decreased incidence of asthma and atopy later in life. Conversely, septic neonates are at increased risk of impaired long-term neurodevelopment. While the positive effects of antibiotics in the setting of infection are irrefutable, prolonged administration of broad-spectrum, empiric antibiotics in neonates without documented infection is associated with increased risk of LOS, necrotizing enterocolitis, or death. Vaccines provide a unique opportunity to prevent infection-associated disease; unfortunately, vaccinations have been largely unsuccessful when administered in the first month of life with the exception of vaccines against hepatitis B and tuberculosis. Future vaccines will require the use of novel adjuvants to overcome this challenge. This review describes the influence of infections, antibiotics, and vaccines during the first days of life, as well as the influence on future health and disease. We will also discuss potential immunomodulating therapies, which may serve to train the preterm immune system and reduce subsequent infectious burden without subjecting neonates to the risks accompanied by virulent pathogens.

Immunological Defects in Neonatal Sepsis and Potential Therapeutic Approaches

Despite advances in critical care medicine, neonatal sepsis remains a major cause of morbidity and mortality worldwide, with the greatest risk affecting very low birth weight, preterm neonates. The presentation of neonatal sepsis varies markedly from its presentation in adults, and there is no clear consensus definition of neonatal sepsis. Previous work has demonstrated that when neonates become septic, death can occur rapidly over a matter of hours or days and is generally associated with inflammation, organ injury, and respiratory failure. Studies of the transcriptomic response by neonates to infection and sepsis have led to unique insights into the early proinflammatory and host protective responses to sepsis. Paradoxically, this early inflammatory response in neonates, although lethal, is clearly less robust relative to children and adults. Similarly, the expression of genes involved in host protective immunity, particularly neutrophil function, is also markedly deficient. As a result, neonates have both a diminished inflammatory and protective immune response to infection which may explain their increased risk to infection, and their reduced ability to clear infections. Such studies imply that novel approaches unique to the neonate will be required for the development of both diagnostics and therapeutics in this high at-risk population.

Patterns of gene expression among murine models of hemorrhagic shock/trauma and sepsis

Controversy remains whether the leukocyte genomic response to trauma or sepsis is dependent upon the initiating stimulus. Previous work illustrated poor correlations between historical models of murine trauma and sepsis (i.e., trauma-hemorrhage and lipopolysaccharide injection, respectively). The aim of this study is to examine the early genomic response in improved murine models of sepsis [cecal ligation and puncture (CLP)] and trauma [polytrauma (PT)] with and without pneumonia (PT+Pp). Groups of naïve, CLP, PT, and PT+Pp mice were killed at 2 h, 1 or 3 days. Total leukocytes were isolated for genome-wide expression analysis, and genes that were found to differ from control (false discovery rate adjusted P < 0.001) were assessed for fold-change differences. Spearman correlations were also performed. For all time points combined (CLP, PT, PT+Pp), there were 10,426 total genes that were found to significantly differ from naïve controls. At 2 h, the transcriptomic changes between CLP and PT showed a positive correlation (rs) of 0.446 (P < 0.0001) but were less positive thereafter. Correlations were significantly improved when we limited the analysis to common genes whose expression differed by a 1.5 fold-change. Both pathway and upstream analyses revealed the activation of genes known to be associated with pathogen-associated and damage-associated molecular pattern signaling, and early activation patterns of expression were very similar between polytrauma and sepsis at the earliest time points. This study demonstrates that the early leukocyte genomic response to sepsis and trauma are very similar in mice.

Improved emergency myelopoiesis and survival in neonatal sepsis by caspase-1/11 ablation

Over one million newborns die annually from sepsis with the highest mortality in premature and low-birthweight infants. The inflammasome plays a central role in the regulation of innate immunity and inflammation, and is presumed to be involved in protective immunity, in large part through the caspase-1-dependent activation of interleukin-1β (IL-1β) and IL-18. Studies in endotoxic shock, however, suggest that endogenous caspase-1 activity and the inflammasome contribute to mortality primarily by promoting excessive systemic inflammatory responses. We examined whether caspase-1 and the inflammasome also regulate neonatal inflammation, host protective immunity and myelopoiesis during polymicrobial sepsis. Neonatal (5-7 days) C57BL/6 and caspase-1/11(-/-) mice underwent a low-lethality caecal slurry model of intra-abdominal sepsis (LD25-45 ). Ablation of caspase-1/11, but not apoptosis-associated speck-like protein containing a CARD domain or nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), improved neonatal survival following septic challenge compared with wild-type mice (P < 0·001), with decreased concentrations of inflammatory cytokines in the serum and peritoneum. Surprisingly, caspase-1/11(-/-) neonates also exhibited increased bone marrow and splenic haematopoietic stem cell expansion (P < 0·001), and increased concentrations of granulocyte and macrophage colony-stimulating factors in the peritoneum (P < 0·001) after sepsis. Ablation of caspase-1/11 signalling was also associated with increased recruitment of peritoneal macrophages and neutrophils (P < 0·001), increased phagocytosis by neutrophils (P = 0·003), and decreased bacterial colonization (P = 0·02) in the peritoneum. These findings suggest that endogenous caspase-1/11 activity, independent of the NLRP3 inflammasome, not only promotes the magnitude of the inflammatory response, but also suppresses protective immunity in the neonate, so contributing to innate immune dysfunction and poor survival in neonatal sepsis.

Outcomes in the physiologically most severe congenital diaphragmatic hernia (CDH) patients: Whom should we treat?

PURPOSE

Centers that care for newborns with congenital diaphragmatic hernia (CDH) may impose selection criteria for offering or limiting aggressive support in those patients most severely affected. The purpose of this study was to analyze outcomes in newborns with highly severe CDH uniformly treated for survival.

METHODS

We reviewed 172 consecutive inborn patients without associated lethal anomalies treated at a single institution with a dedicated CDH program. Survival, respiratory outcome, and time to discharge in the most severe 10% (or fewer) of patients based on the physiologic measures of 5-minute Apgar, CDH Study Group (CDHSG) predicted survival, need for ECMO in the first 6 hours, and need for ECMO in the first 3 hours of life were studied. We also identified patients with best PaCO2 greater than 100 and best pH less than 7.0. A multivariate model (AUC-0.92) predicting mortality was also used to define the most severe 10%.

RESULTS

Of 172 consecutive inborn patients, 18 had a 5-minute Apgar of 3 or less, and 11 survived (61%), 10 had a 5-minute Apgar of 2 or less, and 6 survived (60%), and 6 had a 5-minute Apgar of 1 or less, and 4 survived (67%). Seventeen had a CDHSG predicted survival less than 25%, and 9 survived (53%). Thirteen of 172 required ECMO for rescue in the first 6 hours of life, and 9 survived (69%), including 7 in the first 3 hours, and 5 survived (71%). Despite focused resuscitation in the delivery room and high levels of ventilatory support, 22 patients had a best PCO2 greater than 100 and best pH less than 7.0 for 1 hour or longer. Twelve of these 22 survived to discharge (55%). Of 17 defined by multivariate predictive modeling as the most severe, 8 survived (47%) with zero of the 3 ECMO ineligible prematures surviving. Of the 16 (10%) most severe ECMO-eligible patients, 10 of 16 survived (63%). All survivors were discharged home on no ventilatory support greater than nasal cannula oxygen.

CONCLUSION

In newborn CDH patients without lethal associated anomalies, accepted measures of physiologic severity failed to predict mortality. Survival met or exceeded 50% even in the most severe 10% as defined by these measures. These data support the practice of treating each patient for survival regardless of the physiologic severity in the first hours of life, and selection criteria for not offering ECMO should be reevaluated where practiced.

Feasibility of laparoscopic pyloromyotomy under spinal anesthesia

BACKGROUND

Most agents used for GA are considered to be neurotoxins and affect developing brains in experimental models, leading to a push for spinal anesthesia (SA). There are no reports of laparoscopic pyloromyotomy (LP) performed under SA. We present our experience with LP and SA and discuss feasibility.

METHODS

A retrospective analysis was performed on a consecutive series of patients who underwent an LP. An 'intent to treat' analysis was utilized, and GA was compared to SA. Data regarding patient characteristics, operative intervention, complications, and postoperative course were collected.

RESULTS

Twelve cases had attempted SA for the LP, 9 were successful. During the same time, 12 cases underwent LP under GA. We found no difference for length of procedure, time to the first feed, or the postoperative LOS. The time to leave the OR after conclusion of the procedure was significantly shorter for the SA group (14min vs. 28min, p<0.001). There were no complications from the SA, however three cases had to be converted to GA.

CONCLUSIONS

It is feasible and safe to perform laparoscopic pyloromyotomy under spinal anesthesia. Given the increasing concern over the use of GA in infants, consideration may be given to use of SA for LP.

Ogilvie's syndrome after pediatric spinal deformity surgery: successful treatment with neostigmine

Ogilvie's syndrome is a rare and potentially fatal disease that can easily be mistaken for postoperative ileus. Also known as acute colonic pseudo-obstruction, early recognition and diagnosis of the syndrome allows for treatment prior to bowel perforation and requisite abdominal surgery. The authors report a case of Ogilvie's syndrome following spinal deformity correction and tethered cord release in an adolescent who presented with acute abdominal distension, nausea, and vomiting on postoperative Day 0. The patient was initially diagnosed with adynamic ileus and treated conservatively with bowel rest, reduction in narcotic dosage, and a regimen of stool softeners, laxatives, and enemas. Despite this treatment, her clinical course failed to improve, and she demonstrated significant colonic distension radiographically. Intravenous neostigmine was administered as a bolus with a rapid and dramatic response. This case is the first reported instance of neostigmine use for Ogilvie's syndrome treatment following a pediatric neurosurgical operation.

Delayed emergency myelopoiesis following polymicrobial sepsis in neonates

Neonates have increased susceptibility to infection, which leads to increased mortality. Whether or not this as a result of implicit deficits in neonatal innate immune function or recapitulation of innate immune effector cell populations following infection is unknown. Here, we examine the process of emergency myelopoiesis whereby the host repopulates peripheral myeloid cells lost following the initial infectious insult. As early inflammatory responses are often dependent upon NF-κB and type I IFN signaling, we also examined whether the absence of MyD88, TRIF or MyD88 and TRIF signaling altered the myelopoietic response in neonates to polymicrobial sepsis. Following neonatal polymicrobial septic challenge, hematopoietic stem cell (HSC) expansion in bone marrow and the spleen were both attenuated and delayed in neonates compared with adults. Similar reductions in other precursors were observed in neonates. Similar to adult studies, the expansion of progenitor stem cell populations was also seen in the absence of MyD88 and/or TRIF signaling. Overall, neonates have impaired emergency myelopoiesis in response to sepsis compared with young adults. Despite reports that this expansion may be related to TLR signaling, our data suggest that other factors may be important, as TRIF(-/-) and MyD88(-/-) neonatal HSCs are still able to expand in response to polymicrobial neonatal sepsis.

Appendiceal carcinoids in children--management and outcomes

BACKGROUND

Appendiceal carcinoid tumors are very rare in children, and management has been guided by adult presentations and outcomes. Here, we present our experience with pediatric appendiceal carcinoid tumors.

METHODS

We undertook a retrospective review of all cases of appendiceal carcinoids in children over a 20-y period. Data regarding clinical presentation, diagnosis, pathology, follow-up, and outcomes were collected and analyzed.

RESULTS

We identified 13 cases of appendiceal carcinoids. All cases were diagnosed after appendectomy for presumed appendicitis (nine acute and four interval;), with no patient having carcinoid syndrome. Mean age at diagnosis was 13.7 y, and all but one case was female. Tumor size ranged from microscopic foci of tumor cells to 2.1 cm (mean, 0.93 cm). Seven cases had invasion of the mesoappendix, three of which underwent a subsequent right hemicolectomy. The patient with the largest tumor (2.1 cm) had evidence of lymphatic invasion with three nodes positive for tumor after right colectomy. No patient had elevation of 5-hydroxyindoleacetic acid or serum chromogranin A, and surveillance computed tomographic scans did not reveal any liver metastases.

CONCLUSIONS

This is a relatively large series of carcinoids of the appendix in children. We found no evidence of carcinoid syndrome or metastatic disease in these cases other than lymphatic. The need for a secondary colectomy is perhaps questionable.

Extracorporeal life support in patients with congenital diaphragmatic hernia: how long should we treat?

BACKGROUND

Congenital diaphragmatic hernia (CDH) is a frequently lethal birth defect and, despite advances, extracorporeal life support (ie, extracorporeal membrane oxygenation [ECMO]) is commonly required for severely affected patients. Published data suggest that CDH survival after 2 weeks on ECMO is poor. Many centers limit duration of ECMO support.

STUDY DESIGN

We conducted a single-institution retrospective review of 19 years of CDH patients treated with ECMO, designed to evaluate which factors affect survival and duration of ECMO and define how long patients should be supported.

RESULTS

Of two hundred and forty consecutive CDH patients without lethal associated anomalies, 96 were treated with ECMO and 72 (75%) survived. Eighty required a single run of ECMO and 65 survived (81%), 16 required a second ECMO run and 7 survived (44%). Of patients still on ECMO at 2 weeks, 56% survived, at 3 weeks 46% survived, and at 4 weeks, 43% of patients still on ECMO survived to discharge. After 5 weeks of ECMO, survival had dropped to 15%, and after 40 days of ECMO support there were no survivors. Apgar score at 1 minute, Apgar score at 5 minutes, and Congenital Diaphragmatic Hernia Study Group predicted survival all correlated with survival on ECMO, need for second ECMO, and duration of ECMO. Lung-to-head ratio also correlated with duration of ECMO. All survivors were discharged breathing spontaneously with no support other than nasal cannula oxygen if needed.

CONCLUSIONS

In patients with severe CDH, improvement in pulmonary function sufficient to wean from ECMO can take 4 weeks or longer, and might require a second ECMO run. Pulmonary outcomes in these CDH patients can still be excellent, and the assignment of arbitrary ECMO treatment durations <4 weeks should be avoided.

Development and characterization of a novel in vivo model of carcinoid syndrome

PURPOSE

Carcinoid syndrome, characterized by flushing, diarrhea, and valvular heart disease, can occur following carcinoid tumor metastasis to the liver and systemic release of bioactive hormones into the systemic circulation. Treatment of this devastating disease is hampered by the lack of an in vivo model that recapitulates the clinical syndrome.

EXPERIMENTAL DESIGN

Here, we have injected BON cells, a novel human carcinoid cell line established in our laboratory, into the spleens of athymic nude mice to establish liver metastases.

RESULTS

The majority of mice injected intrasplenically with BON cells developed significant increases in plasma serotonin and urine 5-hydroxyindoleacetic acid, and several mice exhibited mesenteric fibrosis, diarrhea, and fibrotic cardiac valvular disease reminiscent of carcinoid syndrome by both echocardiographic and histopathologic evaluation. Mice pretreated with octreotide, a long-acting somatostatin analogue, or bevacizumab, a vascular endothelial growth factor inhibitor, developed fewer liver metastases and manifestations of carcinoid syndrome, including valvular heart disease.

CONCLUSION

We have provided an important in vivo model to further delineate novel treatment modalities for carcinoid syndrome that will also be useful to elucidate the factors contributing to the sequelae of carcinoid disease (e.g., mesenteric fibrosis and valvular heart disease).

PI3K/Akt activation is critical for early hepatic regeneration after partial hepatectomy

Hepatic resection is associated with rapid proliferation and regeneration of the remnant liver. Phosphatidylinositol 3-kinase (PI3K), composed of a p85alpha regulatory and a p110alpha catalytic subunit, participates in multiple cellular processes, including cell growth and survival; however, the role of PI3K in liver regeneration has not been clearly delineated. In this study, we used the potent PI3K inhibitor wortmannin and small interfering RNA (siRNA) targeting the p85alpha and p110alpha subunits to determine whether total or selective PI3K inhibition would abrogate the proliferative response of the liver after partial hepatectomy in mice. Hepatic resection is associated with an induction in PI3K activity; total PI3K blockade with wortmannin and selective inhibition of p85alpha or p110alpha with siRNA resulted in a significant decrease in hepatocyte proliferation, especially at the earliest time points. Fewer macrophages and Kupffer cells were present in the regenerating liver of mice treated with wortmannin or siRNA to p85alpha or p110alpha, as reflected by a paucity of F4/80-positive cells. Additionally, PI3K inhibition led to an aberrant architecture in the regenerating hepatocytes characterized by vacuolization, lipid deposition, and glycogen accumulation; these changes were not noted in the sham livers. Our data demonstrate that PI3K/Akt pathway activation plays a critical role in the early regenerative response of the liver after resection; inhibition of this pathway markedly abrogates the normal hepatic regenerative response, most likely by inhibiting macrophage infiltration and cytokine elaboration and thus hepatocyte priming for replication.

Molecular mechanisms contributing to glutamine-mediated intestinal cell survival

Glutamine, the most abundant amino acid in the bloodstream, is the preferred fuel source for enterocytes and plays a vital role in the maintenance of mucosal growth. The molecular mechanisms regulating the effects of glutamine on intestinal cell growth and survival are poorly understood. Here, we show that addition of glutamine (1 mmol/l) enhanced rat intestinal epithelial (RIE)-1 cell growth; conversely, glutamine deprivation increased apoptosis as noted by increased DNA fragmentation and caspase-3 activity. To delineate signaling pathways involved in the effects of glutamine on intestinal cells, we assessed activation of extracellular signal-related kinase (ERK), protein kinase D (PKD), and phosphatidylinositol 3-kinase (PI3K)/Akt, which are important pathways in cell growth and survival. Addition of glutamine activated ERK and PKD in RIE-1 cells after a period of glutamine starvation; inhibition of ERK, but not PKD, increased cell apoptosis. Conversely, glutamine starvation alone increased phosphorylated Akt; inhibition of Akt enhanced RIE-1 cell DNA fragmentation. The role of ERK was further delineated using RIE-1 cells stably transfected with an inducible Ras. Apoptosis was significantly increased following ERK inhibition, despite Ras activation. Taken together, these results identify a critical role for the ERK signaling pathways in glutamine-mediated intestinal homeostasis. Furthermore, activation of PI3K/Akt during periods of glutamine deprivation likely occurs as a protective mechanism to limit apoptosis associated with cellular stress. Importantly, our findings provide novel mechanistic insights into the antiapoptotic effects of glutamine in the intestine.

Effectiveness of siRNA uptake in target tissues by various delivery methods

BACKGROUND

RNA interference offers clinical potential as a therapeutic modality for a variety of diseases; the efficacy of in vivo delivery remains poorly understood. The purpose of our study was to compare and contrast short interfering RNA (siRNA) uptake in vivo using various delivery techniques.

METHODS

DY547- and rhodamine-labeled siRNA was administered to mice by one of four delivery methods: (1) hydrodynamic intravenous tail vein injection, (2) standard intravenous tail vein injection, (3) intraperitoneal injection, and (4) rectal administration. Mice were killed over a time course; representative tissue samples were collected and analyzed using fluorescent microscopy to determine siRNA uptake.

RESULTS

siRNA uptake was noted in the liver, kidney, pancreas, spleen, and bone marrow by both hydrodynamic and standard IV injection. siRNA uptake was detected in the spleen, liver, and bone marrow after intraperitoneal administration. Rectal administration resulted in siRNA uptake in the spleen, bone marrow, and colon.

CONCLUSION

Our results demonstrate differential siRNA uptake depending on delivery technique. Importantly, our results demonstrate the potential of siRNA as a systemic therapeutic option in vivo for selected disease processes.