Factors Associated With Post-Extubation Stridor in Infants Intubated in the Pediatric ICU.

BACKGROUND: Post-extubation stridor (PES) is a common problem in the pediatric intensive care unit (PICU) and is associated with extubation failure, longer length of stay, and increased mortality. Infants represent a large proportion of PICU admissions and are at higher risk for PES, making identification and mitigation of factors associated with PES important in this age group. RESEARCH QUESTION: What factors are associated with PES in infants (age less than 1 year) intubated in the PICU? STUDY DESIGN & METHODS: The primary outcome was PES as defined by the need for racemic epinephrine within 6 h of extubation. Secondary outcomes were heliox administration and reintubation. Statistical analyses were performed with Fisher's exact test for univariate analyses and multivariate logistic regression. RESULTS: 518 patient charts were retrospectively reviewed. 24.1% of patients developed PES. Duration of mechanical ventilation greater than 48 h was associated with increased risk of PES (odds ratio [OR] = 1.75, 95% confidence interval [CI] 1.13-2.71, P = .01), as was nonelective intubation (OR = 2.92, 95% CI 1.91-4.46, P < .01). The presence of a cuff, gastroesophageal reflux disease, prematurity, and known upper airway abnormality had no association with PES. 4.0 endotracheal tubes (ETTs) had an increased association with PES compared to 3.5 ETTs (OR = 1.96, 95% CI 1.18-3.27, P < .01). There was no difference in risk of PES between 3.5 and 3.0 ETTs. INTERPRETATION: In infants intubated in the PICU, mechanical ventilation greater than 48 h and nonelective intubation were associated with PES. 4.0 ETTs were associated with higher risk of PES compared to 3.5 ETTs. These findings may help providers in ETT selection and to identify infants that may be at increased risk of PES.

Rapid, multiplexed detection of the let-7 miRNA family using γPNA amphiphiles in micelle-tagging electrophoresis.

miRNA is a promising class of biomarkers whose levels can be assayed to detect various forms of cancer and other serious diseases. These short, noncoding nucleic acids are difficult to detect due to their low abundance and the marginal stability of their duplexes with DNA probes. In addition, miRNAs within the same family have high sequence homology, and often, related miRNA differ in sequence by only a single base. In this report, we demonstrate an independent detection seven members of the let-7 family of miRNA in a single run. Key to success is the use of mini-PEG-substituted PNA amphiphiles (γPNAA) and highly fluorescent DNA nanotags in micelle tagging electrophoresis (MTE). Multiplexed detection is accomplished in capillary electrophoresis (CE) using oligomeric nanotags of pre-programmed lengths where the presence of a specific miRNA links its nanotag to a micelle drag-tag, which shifts the nanotag elution time to a defined region for detection. We further demonstrate that the peak shape and elution time are unaffected by the presence of up to 10 mg/ml of serum protein in the sample, with a total runtime of less than 4 min and a LOD of 10-100 pM. We discuss efforts to substantially decrease the detection limit using nanotags that are >1000 bp in length.

Viral adventitious agent detection using laser force cytology: Intrinsic cell property changes with infection and comparison to in vitro testing.

Adventitious agent testing in biomanufacturing requires assays of broad detection capability to screen for as many infectious agents as possible. The current gold standard for general infectious adventitious virus screening is the in vitro assay in which test articles are cultured onto a panel of different cell lines and observed for cytopathic effect (CPE). However, this assay is inherently subjective due to the nature of visual observation of cell morphology and labor and time intensive, requiring highly trained personnel to identify CPE. Laser force cytology (LFC) is an alternative, automated analytical method that uses a combination of optical and fluidic forces along with imaging to objectively and quantitatively assess CPE in cell culture. Importantly, because LFC uses no labels or antibodies, the assay is appropriate for general adventitious agent testing. Using LFC, changes in cellular features associated with virally infected cells were identified using principal component analysis. Using these features of infected cells, the sensitivity and earliness of detection with LFC was directly compared with the in vitro assay for a diverse panel of viruses incubated with chinese hamster ovary (CHO), Vero, and Medical Research Council cell strain 5 (MRC-5) cells. LFC detected viral infection with a sensitivity equal to the in vitro assay on average, but in certain virus and cell combinations including mouse minute virus (MMV) and reovirus 3 in CHO cells, detection was 4 days earlier and for MMV, the limit of detection was 10-fold lower. Overall, these results demonstrate the ability of LFC to serve as a biopharmaceutical adventitious agent testing methodology with sensitivity equivalent to the in vitro assay, but in an objective and automated manner.

Blood pressure variability during pediatric cardiac surgery is associated with acute kidney injury.

BACKGROUND: Blood pressure variability (BPV), defined as the degree of variation between discrete blood pressure readings, is associated with poor outcomes in acute care settings. Acute kidney injury (AKI) is a common and serious postoperative complication of cardiac surgery with cardiopulmonary bypass (CPB) in children. No studies have yet assessed the association between intraoperative BPV during cardiac surgery with CPB and the development of AKI in children. METHODS: A retrospective chart review of children undergoing cardiac surgery with CPB was performed. Intraoperative BPV was calculated using average real variability (ARV) and standard deviation (SD). Multiple regression models were used to examine the association between BPV and outcomes of AKI, hospital and intensive care unit (PICU) length of stay, and length of mechanical ventilation. RESULTS: Among 231 patients (58% males, median age 8.6 months) reviewed, 51.5% developed AKI (47.9% Stage I, 41.2% Stage II, 10.9% Stage III). In adjusted models, systolic and diastolic ARV were associated with development of any stage AKI (OR 1.40, 95% CI 1.08-1.8 and OR 1.4, 95% CI 1.05-1.8, respectively). Greater diastolic SD was associated with longer PICU length of stay (ß 0.94, 95% CI 0.62-1.2). When stratified by age, greater systolic ARV and SD were associated with AKI in infants ≤ 12 months, but there was no relationship in children > 12 months. CONCLUSIONS: Greater BPV during cardiac surgery with CPB was associated with development of postoperative AKI in infants, suggesting that BPV is a potentially modifiable risk factor for AKI in this high-risk population.

Acute kidney injury and kidney recovery after cardiopulmonary bypass in children.

BACKGROUND: Acute kidney injury (AKI) that improves in the pediatric intensive care unit (PICU) is associated with better outcomes compared to AKI that persists, but no study has investigated whether this also occurs in children undergoing cardiopulmonary bypass (CPB). METHODS: A retrospective study of children ≤18 years who underwent CPB in three children's hospitals was conducted. Patients were classified into groups by kidney recovery after AKI according to Acute Disease Quality Initiative (ADQI) guidelines. Adjusted regression models evaluated associations between kidney recovery group and hospital outcomes. RESULTS: Among 3620 children, AKI developed in 701 (19.4%): 610 transient AKI, 47 persistent AKI, and 44 acute kidney disease (AKD). Mortality increased with severity of kidney recovery group: 4.5% in the never developed AKI group, 8.9% in the transient AKI group, 25.5% in the persistent AKI group, and 31.8% in the AKD group (p <0.0001). In adjusted analysis, transient AKI (HR 1.4, CI 1.02, 2), persistent AKI (HR 22.4, CI 10.2, 49.2), and AKD (HR 3.7, CI 1.7, 7.9) had a greater hazard of mortality when compared to the never developed AKI group. Patients with transient AKI had a longer length of PICU stay than those with never developed AKI (HR 5.1, CI 2.9, 7.3). CONCLUSIONS: Patterns of kidney recovery after AKI were associated with worse PICU outcomes in children after CPB compared to those who did not develop AKI, even after rapid AKI recovery. Identification of factors that increase risk for these AKI patterns is necessary for prevention of AKI during CPB in children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Acute kidney injury in pediatric patients hospitalized with acute COVID-19 and multisystem inflammatory syndrome in children associated with COVID-19.

This study describes the incidence, associated clinical characteristics and outcomes of acute kidney injury in a pediatric cohort with COVID-19 and Multisystem Inflammatory Syndrome in Children (MIS-C). We performed a retrospective study of patients 18 years of age and under admitted to four New York hospitals in the Northwell Health System interned during the height of the COVID-19 pandemic, between March 9 and August 13, 2020. Acute kidney injury was defined and staged according to Kidney Disease: Improving Global Outcomes criteria. The cohort included 152 patients; 97 acute-COVID-19 and 55 with MIS-C associated with COVID-19. Acute kidney injury occurred in 8 with acute-COVID-19 and in 10 with MIS-C. Acute kidney injury, in unadjusted models, was associated with a lower serum albumin level (odds ratio 0.17; 95% confidence interval 0.07, 0.39) and higher white blood cell counts (odds ratio 1.11; 95% confidence interval 1.04, 1.2). Patients with MIS-C and acute kidney injury had significantly greater rates of systolic dysfunction, compared to those without (80% vs 49%). In unadjusted models, patients with acute kidney injury had 8.4 days longer hospitalizations compared to patients without acute kidney injury (95% confidence interval, 4.4-6.7). Acute kidney injury in acute-COVID-19 and MIS-C may be related to inflammation and/or dehydration. Further research in larger pediatric cohorts is needed to better characterize risk factors for acute kidney injury in acute-COVID-19 and with MIS-C consequent to COVID-19.

Characteristics, Cardiac Involvement, and Outcomes of Multisystem Inflammatory Syndrome of Childhood Associated with severe acute respiratory syndrome coronavirus 2 Infection.

We report on the presentation and course of 33 children with multisystem inflammatory syndrome in children and confirmed severe acute respiratory syndrome coronavirus 2 infection. Hemodynamic instability and cardiac dysfunction were prominent findings, with most patients exhibiting rapid resolution following anti-inflammatory therapy.

Veno-venous extracorporeal membrane oxygenation for COVID-19-associated pediatric acute respiratory distress syndrome.

BACKGROUND: The SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) coronavirus has emerged as a highly contagious respiratory pathogen causing severe acute lung injury. Extracorporeal membrane oxygenation is a standard tool for the management of life-threatening acute respiratory distress syndrome, but the use of this resource-intensive therapy has come into question due to strained medical systems and limited proven treatments for COVID-19. CASE SUMMARY: A 16-year-old female with obesity presented with fever, myalgias, cough, and tachypnea and was diagnosed with COVID-19. She progressed to severe pediatric acute respiratory distress syndrome requiring intubation on hospital day 4 and cannulation to veno-venous extracorporeal membrane oxygenation on hospital day 6. The patient received remdesivir, steroids, and anakinra. The patient was successfully decannulated on hospital day 12 and was discharged home on hospital day 21. CONCLUSION: We report the use of veno-venous extracorporeal membrane oxygenation as a bridge to lung recovery in a pediatric patient with severe pediatric acute respiratory distress syndrome due to COVID-19.

DNA Binding and Sensor Specificity of FarR, a Novel TetR Family Regulator Required for Induction of the Fatty Acid Efflux Pump FarE in Staphylococcus aureus.

Divergent genes in Staphylococcus aureus USA300 encode the efflux pump FarE and TetR family regulator FarR, which confer resistance to antimicrobial unsaturated fatty acids. To study their regulation, we constructed USA300 ΔfarER, which exhibited a 2-fold reduction in MIC of linoleic acid. farE expressed from its native promoter on pLIfarE conferred increased resistance to USA300 but not USA300 ΔfarER Complementation of USA300 ΔfarER with pLIfarR also had no effect, whereas resistance was restored with pLIfarER or through ectopic expression of farE In electrophoretic mobility shift assays, FarR bound to three different oligonucleotide probes that each contained a TAGWTTA motif, occurring as (i) a singular motif overlapping the -10 element of the P farR promoter, (ii) in palindrome PAL1 immediately in the 3' direction of P farR , or (iii) within PAL2 upstream of the predicted P farE promoter. FarR autorepressed its expression through cooperative binding to PAL1 and the adjacent TAGWTTA motif in P farR Consistent with reports that S. aureus does not metabolize fatty acids through acyl coenzyme A (acyl-CoA) intermediates, DNA binding activity of FarR was not affected by linoleoyl-CoA. Conversely, induction of farE required fatty acid kinase FakA, which catalyzes the first metabolic step in the incorporation of unsaturated fatty acids into phospholipid. We conclude that FarR is needed to promote the expression of farE while strongly autorepressing its own expression, and our data are consistent with a model whereby FarR interacts with a FakA-dependent product of exogenous fatty acid metabolism to ensure that efflux only occurs when the metabolic capacity for incorporation of fatty acid into phospholipid is exceeded.IMPORTANCE Here, we describe the DNA binding and sensor specificity of FarR, a novel TetR family regulator (TFR) in Staphylococcus aureus Unlike the majority of TFRs that have been characterized, which function to repress a divergently transcribed gene, we find that FarR is needed to promote expression of the divergently transcribed farE gene, encoding a resistance-nodulation-division (RND) family efflux pump that is induced in response to antimicrobial unsaturated fatty acids. Induction of farE was dependent on the function of the fatty acid kinase FakA, which catalyzes the first metabolic step in the incorporation of exogenous unsaturated fatty acids into phospholipid. This represents a novel example of TFR function.

Short-Term Adverse Outcomes Associated With Hypoglycemia in Critically Ill Children.

OBJECTIVES: Previous studies report worse short-term outcomes with hypoglycemia in critically ill children. These studies relied on intermittent blood glucose measurements, which may have introduced detection bias. We analyzed data from the Heart And Lung Failure-Pediatric INsulin Titration trial to determine the association of hypoglycemia with adverse short-term outcomes in critically ill children. DESIGN: Nested case-control study. SETTING: Thirty-five PICUs. A computerized algorithm that guided the timing of blood glucose measurements and titration of insulin infusion, continuous glucose monitors, and standardized glucose infusion rates were used to minimize hypoglycemia. PATIENTS: Nondiabetic children with cardiovascular and/or respiratory failure and hyperglycemia. Cases were children with any hypoglycemia (blood glucose < 60 mg/dL), whereas controls were children without hypoglycemia. Each case was matched with up to four unique controls according to age group, study day, and severity of illness. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 112 (16.0%) of 698 children who received the Heart And Lung Failure-Pediatric INsulin Titration protocol developed hypoglycemia, including 25 (3.6%) who developed severe hypoglycemia (blood glucose < 40 mg/dL). Of these, 110 cases were matched to 427 controls. Hypoglycemia was associated with fewer ICU-free days (median, 15.3 vs 20.2 d; p = 0.04) and fewer hospital-free days (0 vs 7 d; p = 0.01) through day 28. Ventilator-free days through day 28 and mortality at 28 and 90 days did not differ between groups. More children with insulin-induced versus noninsulin-induced hypoglycemia had zero ICU-free days (35.8% vs 20.9%; p = 0.008). Outcomes did not differ between children with severe versus nonsevere hypoglycemia or those with recurrent versus isolated hypoglycemia. CONCLUSIONS: When a computerized algorithm, continuous glucose monitors and standardized glucose infusion rates were used to manage hyperglycemia in critically ill children with cardiovascular and/or respiratory failure, severe hypoglycemia (blood glucose < 40 mg/dL) was uncommon, but any hypoglycemia (blood glucose < 60 mg/dL) remained common and was associated with worse short-term outcomes.

Is Liver Ultrasound Useful as Part of the Surveillance Strategy following Potentially Curative Colorectal Cancer Resection?

BACKGROUND: Optimal surveillance monitoring following curative resection of colorectal cancer remains unclear. Guidelines recommend computed tomography (CT)-based imaging for the initial 3 years following surgical intervention due to the high rates of local and distant recurrence. However, there is currently limited supporting evidence for this strategy. Our current follow-up practice is to offer annual interval abdominal ultrasound and abdominal/pelvis CT scans starting at 6 and 12 months with the sequence of radiological follow-up remaining at the discretion of each clinician. We aim to establish the additional diagnostic benefit of abdominal ultrasound to CT scans in colorectal cancer surveillance follow-up. METHODS: All patients who underwent colorectal resection with curative intent in our region during a single year were included. Patients were detected from a prospectively collected pathology database and supplemented retrospectively with patient demographics, imaging reports, and mortality data. RESULTS: A total of 243 patients (male n = 135, 55.6%) were included. There was a mortality rate of 31.3% over the study period. Patients who received abdominal ultrasound as their initial imaging modality (n = 64, 26.3%) were significantly older, had less severe disease, and a significantly lower mortality rate when compared to CT -patients (n = 148, 60.9%). All patients with new hepatic disease detected by ultrasound scans had their management discussed in multi-disciplinary team meetings before their next scheduled CT. CONCLUSION: In an era where cross-sectional imaging of colorectal cancer is commonplace, abdominal ultrasound offers additional benefit to CT as a postoperative imaging adjunct for the detection of hepatic disease recurrence.

Safety of Terbutaline for Treatment of Acute Severe Pediatric Asthma.

OBJECTIVES: The use of continuous intravenous terbutaline treatment in severe asthma attacks has been hampered by the lack of well-powered clinical trials where effects of such treatment are described in detail. Here, we aimed to provide a descriptive report on the largest cohort of severe pediatric asthma patients treated with terbutaline. METHODS: The study was conducted in a pediatric intensive care unit in a large metropolitan tertiary care university hospital on 124 patients receiving terbutaline infusion. To stratify the effect of, and determine any age-related differences of, terbutaline, the patients were divided into 3 age groups (0-6 years, 7-12 years, and 13-18 years). Clinical response and the potential harmful effects of terbutaline infusion were determined. RESULTS: There were significant reductions in systolic (varying between 86% and 93% of the baseline) and diastolic blood pressures (varying between 74% and 86% of the baseline level). However, the values returned to baseline level shortly after discontinuation of infusion. Terbutaline increased heart rates in all groups shortly after initiation (9%-13% above baseline), which returned to below baseline levels 1 hour after discontinuation. Serum potassium levels were also reduced in all patients compared to their baseline values after initiation of terbutaline infusion. However, none of the subjects required potassium replacement. CONCLUSIONS: The results indicate that overall, terbutaline infusion was well tolerated without irreversible adverse effects of the treatment. Although hemodynamic and metabolic disturbances occurred, these were clinically easily managed and posed little risk in emergency department or pediatric intensive care unit.

Sedation Management in Children Supported on Extracorporeal Membrane Oxygenation for Acute Respiratory Failure.

OBJECTIVES: To describe sedation management in children supported on extracorporeal membrane oxygenation for acute respiratory failure. DESIGN: Secondary analysis of prospectively collected data from a multicenter randomized trial of sedation (Randomized Evaluation of Sedation Titration for Respiratory Failure). SETTING: Twenty-one U.S. PICUs. PATIENTS: One thousand two hundred fifty-five children, 2 weeks to 17 years old, with moderate/severe pediatric acute respiratory distress syndrome. INTERVENTIONS: Sedation managed per usual care or Randomized Evaluation of Sedation Titration for Respiratory Failure protocol. MEASUREMENTS AND MAIN RESULTS: Sixty-one Randomized Evaluation of Sedation Titration for Respiratory Failure patients (5%) with moderate/severe pediatric acute respiratory distress syndrome were supported on extracorporeal membrane oxygenation, including 29 managed per Randomized Evaluation of Sedation Titration for Respiratory Failure protocol. Most extracorporeal membrane oxygenation patients received neuromuscular blockade (46%) or were heavily sedated with State Behavioral Scale scores -3/-2 (34%) by extracorporeal membrane oxygenation day 3. Median opioid and benzodiazepine doses on the day of cannulation, 0.15 mg/kg/hr (3.7 mg/kg/d) and 0.11 mg/kg/hr (2.8 mg/kg/d), increased by 36% and 58%, respectively, by extracorporeal membrane oxygenation day 3. In the 41 patients successfully decannulated prior to study discharge, patients were receiving 0.40 mg/kg/hr opioids (9.7 mg/kg/d) and 0.39 mg/kg/hr benzodiazepines (9.4 mg/kg/d) at decannulation, an increase from cannulation of 108% and 192%, respectively (both p < 0.001). Extracorporeal membrane oxygenation patients experienced more clinically significant iatrogenic withdrawal than moderate/severe pediatric acute respiratory distress syndrome patients managed without extracorporeal membrane oxygenation support (p < 0.001). Compared to extracorporeal membrane oxygenation patients managed per Randomized Evaluation of Sedation Titration for Respiratory Failure protocol, usual care extracorporeal membrane oxygenation patients received more opioids during the study period (mean cumulative dose of 183.0 vs 89.8 mg/kg; p = 0.02), over 6.5 greater exposure days (p = 0.002) with no differences in wakefulness or agitation. CONCLUSIONS: In children, the initiation of extracorporeal membrane oxygenation support is associated with deep sedation, substantial sedative exposure, and increased frequency of iatrogenic withdrawal syndrome. A standardized, goal-directed, nurse-driven sedation protocol may help mitigate these effects.

Defining leadership competencies for pediatric critical care fellows: Results of a national needs assessment.

INTRODUCTION: Physicians in training, including those in Pediatric Critical Care Medicine, must develop clinical leadership skills in preparation to lead multidisciplinary teams during their careers. This study seeks to identify multidisciplinary perceptions of leadership skills important for Pediatric Critical Care Medicine fellows to attain prior to fellowship completion. METHODS: We performed a multi-institutional survey of Pediatric Critical Care Medicine attendings, fellows, and nurses. Subjects were asked to rate importance of 59 leadership skills, behaviors, and attitudes for Pediatric Critical Care practitioners and to identify whether these skills should be achieved before completing fellowship. Skills with the highest ratings by respondents were deemed essential. RESULTS: Five hundred and eighteen subjects completed the survey. Of 59 items, only one item ("displays honesty and integrity") was considered essential by all respondents. When analyzed by discipline, nurses identified 21 behaviors essential, fellows 3, and attendings 1 (p < 0.05). Nurses differed (p < 0.05) from attendings in their opinion of importance in 64% (38/59) of skills. CONCLUSIONS: Despite significant variability among Pediatric Critical Care attendings, fellows, and nurses in identifying which clinical leadership competencies are important for graduating Pediatric Critical Care fellows, they place the highest importance on skills in self-management and self-awareness. Leadership skills identified as most important may guide the development of interventions to improve trainee education and interprofessional care.

Genome-wide association and identification of candidate genes for age at puberty in swine.

BACKGROUND: Reproductive efficiency has a great impact on the economic success of pork production. Gilts comprise a significant portion of breeding females and gilts that reach puberty earlier tend to stay in the herd longer and be more productive. About 10 to 30% of gilts never farrow a litter and the most common reasons for removal are anestrus and failure to conceive. Puberty in pigs is usually defined as the female's first estrus in the presence of boar stimulation. Genetic markers associated with age at puberty will allow for selection on age at puberty and traits correlated with sow lifetime productivity. RESULTS: Gilts (n = 759) with estrus detection measurements ranging from 140-240 days were genotyped using the Illumina PorcineSNP60 BeadChip and SNP were tested for significant effects with a Bayesian approach using GENSEL software. Of the available 8111 five-marker windows, 27 were found to be statistically significant with a comparison-wise error of P < 0.01. Ten QTL were highly significant at P < 0.005 level. Two QTL, one on SSC12 at 15 Mb and the other on SSC7 at 75 Mb, explained 16.87% of the total genetic variance. The most compelling candidate genes in these two regions included the growth hormone gene (GH1) on SSC12 and PRKD1 on SSC7. Several loci confirmed associations previously identified for age at puberty in the pig and loci for age at menarche in humans. CONCLUSIONS: Several of the loci identified in this study have a physiological role for the onset of puberty and a genetic basis for sexual maturation in humans. Understanding the genes involved in regulation of the onset of puberty would allow for the improvement of reproductive efficiency in swine. Because age at puberty is a predictive factor for sow longevity and lifetime productivity, but not routinely measured or selected for in commercial herds, it would be beneficial to be able to use genomic or marker-assisted selection to improve these traits.

Nosocomial Bloodstream Infections in Patients Receiving Extracorporeal Life Support: Variability in Prevention Practices: A Survey of the Extracorporeal Life Support Organization Members.

Nosocomial blood stream infections (BSIs) increase both the morbidity and the mortality of patients receiving extracorporeal life support (ECLS). The aim of this study was to identify common practices for blood stream infection prevention among national Extracorporeal Membrane Oxygenation (ECMO) programs. An electronic survey that comprised of a 16-item questionnaire was sent out to all ECMO program directors and coordinators within the United States that are part of the Extracorporeal Life Support Organization (ELSO) registry. A total of 152 institutions in 40 states were surveyed, with 85 (55%) responses. One-quarter of the institutions responded that an ECMO infection-prevention bundle or checklist was used during the cannulation. Less than half responded that an ECMO infection-prevention bundle or checklist was used for cannula maintenance, although a majority (82.9%) of institutions responded that a "standard approach to cannula dressings" was used. Half of the respondents reported antimicrobial prophylaxis was routinely prescribed for patients on ECMO, although specific regimens varied widely. Of the institutions, 34.2% reported sending daily blood cultures as part of routine surveillance. Smaller programs were more likely to send daily surveillance blood cultures (58.8%, P < .01). We found no clear consensus on practices used to prevent BSI in patients receiving ECMO.

Acute Kidney Injury in Neonates in the PICU.

OBJECTIVES: Acute kidney injury is an independent risk factor for morbidity and mortality in critically ill children in the PICU. Neonates are a particularly vulnerable subgroup regarding acute kidney injury. The objectives were to define the prevalence of acute kidney injury to assess independent risk factors, for the development of acute kidney injury, and to determine the impact of acute kidney injury on outcomes in critically ill neonates without history of cardiac surgery. DESIGN: A retrospective study of neonates (≤ 28 d old and ≥ 32 wk of gestational age) admitted to a tertiary PICU was conducted. Acute kidney injury was classified using the Kidney Disease: Improving Global Outcomes definition. SETTING: PICU in a tertiary children's hospital. PATIENTS: A total of 80 neonates (62% male neonates) with a median gestational age of 38 weeks (interquartile range, 37-39 wk) were reviewed. INTERVENTION: None. MEASUREMENT AND MAIN RESULTS: Acute kidney injury was found in 35% (n = 28) of neonates. Fourteen (50%) reached stage I, 8 (29%) stage II, and 6 (21%) stage III acute kidney injury. Younger age was associated with acute kidney injury (p = 0.016; odds ratio, 0.93; CI, 0.88-0.98). In regression analysis adjusted for age and gender, bacteremia (p = 0.014; odds ratio, 5.4; CI, 1.4-20.4) and maximum sodium concentration (p = 0.02; odds ratio, 1.12; CI, 1.02-1.24) were associated with acute kidney injury. Mortality (p = 0.03) and length of mechanical ventilation (p = 0.001) were significantly higher in neonates with acute kidney injury compared with those without acute kidney injury. In an adjusted regression model, stages 2 and 3 combined were associated with increased mortality (p = 0.02; odds ratio, 5.64; CI, 1.33-23.8), length of ventilation (p = 0.016; ß, 12.2; CI, 2.39-22.0), and length of stay (p = 0.049; ß, 12.2; CI, 0.073-24.3). CONCLUSIONS: Acute kidney injury is common in neonates not requiring cardiac surgery and is associated with increased morbidity and mortality. Age, bacteremia, and maximum sodium concentration are independently associated with the development of acute kidney injury in this population.

Dexmedetomidine Use in Critically Ill Children With Acute Respiratory Failure.

OBJECTIVE: Care of critically ill children includes sedation but current therapies are suboptimal. To describe dexmedetomidine use in children supported on mechanical ventilation for acute respiratory failure. DESIGN: Secondary analysis of data from the Randomized Evaluation of Sedation Titration for Respiratory Failure clinical trial. SETTING: Thirty-one PICUs. PATIENTS: Data from 2,449 children; 2 weeks to 17 years old. INTERVENTIONS: Sedation practices were unrestrained in the usual care arm. Patients were categorized as receiving dexmedetomidine as a primary sedative, secondary sedative, periextubation agent, or never prescribed. Dexmedetomidine exposure and sedation and clinical profiles are described. MEASUREMENTS AND MAIN RESULTS: Of 1,224 usual care patients, 596 (49%) received dexmedetomidine. Dexmedetomidine as a primary sedative patients (n = 138; 11%) were less critically ill (Pediatric Risk of Mortality III-12 score median, 6 [interquartile range, 3-11]) and when compared with all other cohorts, experienced more episodic agitation. In the intervention group, time in sedation target improved from 28% to 50% within 1 day of initiating dexmedetomidine as a primary sedative. Dexmedetomidine as a secondary sedative usual care patients (n = 280; 23%) included more children with severe pediatric acute respiratory distress syndrome or organ failure. Dexmedetomidine as a secondary sedative patients experienced more inadequate pain (22% vs 11%) and sedation (31% vs 16%) events. Dexmedetomidine as a periextubation agent patients (n = 178; 15%) were those known to not tolerate an awake, intubated state and experienced a shorter ventilator weaning process (2.1 vs 2.3 d). CONCLUSIONS: Our data support the use of dexmedetomidine as a primary agent in low criticality patients offering the benefit of rapid achievement of targeted sedation levels. Dexmedetomidine as a secondary agent does not appear to add benefit. The use of dexmedetomidine to facilitate extubation in children intolerant of an awake, intubated state may abbreviate ventilator weaning. These data support a broader armamentarium of pediatric critical care sedation.

Inducible Expression of a Resistance-Nodulation-Division-Type Efflux Pump in Staphylococcus aureus Provides Resistance to Linoleic and Arachidonic Acids.

UNLABELLED: Although Staphylococcus aureus is exposed to antimicrobial fatty acids on the skin, in nasal secretions, and in abscesses, a specific mechanism of inducible resistance to this important facet of innate immunity has not been identified. Here, we have sequenced the genome of S. aureus USA300 variants selected for their ability to grow at an elevated concentration of linoleic acid. The fatty acid-resistant clone FAR7 had a single nucleotide polymorphism resulting in an H121Y substitution in an uncharacterized transcriptional regulator belonging to the AcrR family, which was divergently transcribed from a gene encoding a member of the resistance-nodulation-division superfamily of multidrug efflux pumps. We named these genes farR and farE, for regulator and effector of fatty acid resistance, respectively. Several lines of evidence indicated that FarE promotes efflux of antimicrobial fatty acids and is regulated by FarR. First, expression of farE was strongly induced by arachidonic and linoleic acids in an farR-dependent manner. Second, an H121Y substitution in FarR resulted in increased expression of farE and was alone sufficient to promote increased resistance of S. aureus to linoleic acid. Third, inactivation of farE resulted in a significant reduction in the inducible resistance of S. aureus to the bactericidal activity of 100 µM linoleic acid, increased accumulation of [(14)C]linoleic acid by growing cells, and severely impaired growth in the presence of nonbactericidal concentrations of linoleic acid. Cumulatively, these findings represent the first description of a specific mechanism of inducible resistance to antimicrobial fatty acids in a Gram-positive pathogen. IMPORTANCE: Staphylococcus aureus colonizes approximately 25% of humans and is a leading cause of human infectious morbidity and mortality. To persist on human hosts, S. aureus must have intrinsic defense mechanisms to cope with antimicrobial fatty acids, which comprise an important component of human innate defense mechanisms. We have identified a novel pair of genes, farR and farE, that constitute a dedicated regulator and effector of S. aureus resistance to linoleic and arachidonic acids, which are major fatty acids in human membrane phospholipid. Expression of farE, which encodes an efflux pump, is induced in an farR-dependent mechanism, in response to these antimicrobial fatty acids that would be encountered in a tissue abscess.

A 502-Base Free-Solution Electrophoretic DNA Sequencing Method Using End-Attached Wormlike Micelles.

We demonstrate that the use of wormlike nonionic micelles as drag-tags in end-labeled free-solution electrophoresis ("micelle-ELFSE") provides single-base resolution of Sanger sequencing products up to 502 bases in length, a nearly 2-fold improvement over reported ELFSE separations. "CiEj" running buffers containing 48 mM C12E5, 6 mM C10E5, and 3 M urea (32.5 °C) form wormlike micelles that provide a drag equivalent to an uncharged DNA fragment with a length (α) of 509 bases (effective Rh = 27 nm). Runtime in a 40 cm capillary (30 kV) was 35 min for elution of all products down to the 26-base primer. We also show that smaller Triton X-100 micelles give a read length of 103 bases in a 4 min run, so that a combined analysis of the Sanger products using the two buffers in separate capillaries could be completed in 14 min for the full range of lengths. A van Deemter analysis shows that resolution is limited by diffusion-based peak broadening and wall adsorption. Effects of drag-tag polydispersity are not observed, despite the inherent polydispersity of the wormlike micelles. We ascribe this to a stochastic size-sampling process that occurs as micelle size fluctuates rapidly during the runtime. A theoretical model of the process suggests that fluctuations occur with a time scale less than 10 ms, consistent with the monomer exchange process in nonionic micelles. The CiEj buffer has a low viscosity (2.7 cP) and appears to be semidilute in micelle concentration. The large drag-tag size of the CiEj buffers leads to steric segregation of the DNA and tag for short fragments and attendant mobility shifts.