High-Density Blood Transcriptomics Reveals Precision Immune Signatures of SARS-CoV-2 Infection in Hospitalized Individuals.

The immune response to COVID-19 infection is variable. How COVID-19 influences clinical outcomes in hospitalized patients needs to be understood through readily obtainable biological materials, such as blood. We hypothesized that a high-density analysis of host (and pathogen) blood RNA in hospitalized patients with SARS-CoV-2 would provide mechanistic insights into the heterogeneity of response amongst COVID-19 patients when combined with advanced multidimensional bioinformatics for RNA. We enrolled 36 hospitalized COVID-19 patients (11 died) and 15 controls, collecting 74 blood PAXgene RNA tubes at multiple timepoints, one early and in 23 patients after treatment with various therapies. Total RNAseq was performed at high-density, with >160 million paired-end, 150 base pair reads per sample, representing the most sequenced bases per sample for any publicly deposited blood PAXgene tube study. There are 770 genes significantly altered in the blood of COVID-19 patients associated with antiviral defense, mitotic cell cycle, type I interferon signaling, and severe viral infections. Immune genes activated include those associated with neutrophil mechanisms, secretory granules, and neutrophil extracellular traps (NETs), along with decreased gene expression in lymphocytes and clonal expansion of the acquired immune response. Therapies such as convalescent serum and dexamethasone reduced many of the blood expression signatures of COVID-19. Severely ill or deceased patients are marked by various secondary infections, unique gene patterns, dysregulated innate response, and peripheral organ damage not otherwise found in the cohort. High-density transcriptomic data offers shared gene expression signatures, providing unique insights into the immune system and individualized signatures of patients that could be used to understand the patient's clinical condition. Whole blood transcriptomics provides patient-level insights for immune activation, immune repertoire, and secondary infections that can further guide precision treatment.

Hexosylceramides and Glycerophosphatidylcholine GPC(36:1) Increase in Multi-Organ Dysfunction Syndrome Patients with Pediatric Intensive Care Unit Admission over 8-Day Hospitalization.

Glycero- and sphingo-lipids are important in plasma membrane structure, caloric storage and signaling. An un-targeted lipidomics approach for a cohort of critically ill pediatric intensive care unit (PICU) patients undergoing multi-organ dysfunction syndrome (MODS) was compared to sedation controls. After IRB approval, patients meeting the criteria for MODS were screened, consented (n = 24), and blood samples were collected from the PICU at HDVCH, Michigan; eight patients needed veno-arterial extracorporeal membrane oxygenation (VA ECMO). Sedation controls were presenting for routine sedation (n = 4). Plasma lipid profiles were determined by nano-electrospray (nESI) direct infusion high resolution/accurate mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Biostatistics analysis was performed using R v 3.6.0. Sixty-one patient samples over three time points revealed a ceramide metabolite, hexosylceramide (Hex-Cer) was high across all time points (mean 1.63-3.19%; vs. controls 0.22%). Fourteen species statistically differentiated from sedation controls (p-value ≤ 0.05); sphingomyelin (SM) [SM(d18:1/23:0), SM(d18:1/22:0), SM(d18:1/23:1), SM(d18:1/21:0), SM(d18:1/24:0)]; and glycerophosphotidylcholine (GPC) [GPC(36:01), GPC(18:00), GPC(O:34:02), GPC(18:02), GPC(38:05), GPC(O:34:03), GPC(16:00), GPC(40:05), GPC(O:36:03)]. Hex-Cer has been shown to be involved in viral infection and may be at play during acute illness. GPC(36:01) was elevated in all MODS patients at all time points and is associated with inflammation and brain injury.

Balancing precision versus cohort transcriptomic analysis of acute and recovery phase of viral bronchiolitis.

Viral infections affecting the lower respiratory tract place enormous burdens on hospitals. As neither vaccines nor antiviral agents exist for many viruses, understanding risk factors and outcomes in each patient using minimally invasive analysis, such as blood, can lead to improved health care delivery. A cohort of PAXgene RNA sequencing of infants admitted with moderate or severe acute bronchiolitis and respiratory syncytial virus were compared with case-control statistical analysis and cohort-based outlier mapping for precision transcriptomics. Patients with severe bronchiolitis had signatures connected to the immune system, interferon signaling, and cytokine signaling, with marked sex differences in XIST, RPS4Y1, KDM5D, and LINC00278 for severity. Several patients had unique secondary infections, cytokine activation, immune responses, biological pathways, and immune cell activation, highlighting the need for defining patient-level transcriptomic signatures. Balancing relative contributions of cohort-based biomarker discoveries with patient's biological responses is needed to understand the totality of mechanisms of adverse outcomes in viral bronchiolitis.

Pediatric Multi-Organ Dysfunction Syndrome: Analysis by an Untargeted "Shotgun" Lipidomic Approach Reveals Low-Abundance Plasma Phospholipids and Dynamic Recovery over 8-Day Period, a Single-Center Observational Study.

Lipids are molecules involved in metabolism and inflammation. This study investigates the plasma lipidome for markers of severity and nutritional status in critically ill children. Children with multi-organ dysfunction syndrome (MODS) (n = 24) are analyzed at three time-points and cross-referenced to sedation controls (n = 4) for a total of N = 28. Eight of the patients with MODS, needed veno-arterial extracorporeal membrane oxygenation (VA ECMO) support to survive. Blood plasma lipid profiles are quantified by nano-electrospray (nESI), direct infusion high resolution/accurate mass spectrometry (MS), and tandem mass spectrometry (MS/MS), and compared to nutritional profiles and pediatric logistic organ dysfunction (PELOD) scores. Our results show that PELOD scores were not significantly different between MODS and ECMO cases across time-points (p = 0.66). Lipid profiling provides stratification between sedation controls and all MODS patients for total lysophosphatidylserine (lysoPS) (p-value = 0.004), total phosphatidylserine (PS) (p-value = 0.015), and total ether-linked phosphatidylethanolamine (ether-PE) (p-value = 0.03) after adjusting for sex and age. Nutrition intake over time did not correlate with changes in lipid profiles, as measured by caloric and protein intake. Lipid measurement in the intensive care environment shows dynamic changes over an 8-day pediatric intensive care unit (PICU) course, suggesting novel metabolic indicators for defining critically ill children.

The Feasibility of Studying Metabolites in PICU Multi-Organ Dysfunction Syndrome Patients over an 8-Day Course Using an Untargeted Approach.

Metabolites are generated from critical biological functions and metabolism. This pediatric study reviewed plasma metabolites in patients suffering from multi-organ dysfunction syndrome (MODS) in the pediatric intensive care unit (PICU) using an untargeted metabolomics approach. Patients meeting the criteria for MODS were screened for eligibility and consented (n = 24), and blood samples were collected at baseline, 72 h, and 8 days; control patients (n = 4) presented for routine sedation in an outpatient setting. A subset of MODS patients (n = 8) required additional support with veno-atrial extracorporeal membrane oxygenation (VA-ECMO) therapy. Metabolites from thawed blood plasma were determined from ion pairing reversed-phase liquid chromatography-mass spectrometry (LC-MS) analysis. Chromatographic peak alignment, identification, relative quantitation, and statistical and bioinformatics evaluation were performed using MAVEN and MetaboAnalyst 4.0. Metabolite analysis revealed 115 peaks per sample. From the partial least squares-discriminant analysis (PLS-DA) with variance of importance (VIP) scores above ≥2.0, 7 dynamic metabolites emerged over the three time points: tauro-chenodeoxycholic acid (TCDCA), hexose, p-hydroxybenzoate, hydroxyphenylacetic acid (HPLA), 2_3-dihydroxybenzoic acid, 2-keto-isovalerate, and deoxyribose phosphate. After Bonferroni adjustment for repeated measures, hexose and p-hydroxybenzoate were significant at one time point or more. Kendall's tau-b test was used for internal validation of creatinine. Metabolites may be benign or significant in describing a patient's pathophysiology and require operator interpretation.

Preadmission Diet and Zip Code Influences the Pediatric Critical Care Clinical Course for Infants with Severe Respiratory Illness ( N = 187).

We examined preadmission diet and zip code in infants with severe respiratory illness in the pediatric critical care unit. Patients aged 0 to 5 months admitted to the Helen DeVos Children's Hospital from January 2011 to May 2017 ( N = 187), as exclusively formula, exclusively breastfed or mixed diet were included. Formula-fed infants ( n = 88; 47%) clustered to zip codes with lower median incomes (<0.005), used public insurance as their payer type ( p < 0.005), and were prescribed more ranitidine ( p < 0.05) on admission.

Dietary Intake Influences Metabolites in Healthy Infants: A Scoping Review.

Metabolites are generated from exogenous sources such as diet. This scoping review will summarize nascent metabolite literature and discriminating metabolites for formula vs. human- milk-fed infants. Using the PICOS framework (P-Patient, Problem or Population; I-Intervention; C-Comparison; O-Outcome; S-Study Design) and PRISMA item-reporting protocols, infants less than 12 months old, full-term, and previously healthy were included. Protocol was registered with Open Science Framework (OSF). Publications from 1 January 2009-2019 were selected, for various biofluids, study designs, and techniques (such as high-performance liquid chromatography (HPLC)). From 711 articles, blinded screening of 214 articles using Abstrackr® software, resulted in 24 for final review. Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guidelines were adopted, which included a 24-point checklist. Articles were stratified according to biofluid. Of articles reporting discriminating metabolites between formula- and human milk-fed infants, 62.5% (5/8) of plasma/serum/dried blood spot, 88% (7/8) of urine and 100% (6/6) of feces related articles reported such discriminating metabolites. Overall, no differences were found between analytical approach used (targeted (n = 9) vs. un-targeted (n = 10)). Current articles are limited by small sample sizes and differing methodological approaches. Of the metabolites reviewed herein, fecal metabolites provided the greatest distinction between diets, which may be indicative of usefulness for future diet metabolite-focused work.

Virus-induced genetics revealed by multidimensional precision medicine transcriptional workflow applicable to COVID-19.

Precision medicine requires the translation of basic biological understanding to medical insights, mainly applied to characterization of each unique patient. In many clinical settings, this requires tools that can be broadly used to identify pathology and risks. Patients often present to the intensive care unit with broad phenotypes, including multiple organ dysfunction syndrome (MODS) resulting from infection, trauma, or other disease processes. Etiology and outcomes are unique to individuals, making it difficult to cohort patients with MODS, but presenting a prime target for testing/developing tools for precision medicine. Using multitime point whole blood (cellular/acellular) total transcriptomics in 27 patients, we highlight the promise of simultaneously mapping viral/bacterial load, cell composition, tissue damage biomarkers, balance between syndromic biology versus environmental response, and unique biological insights in each patient using a single platform measurement. Integration of a transcriptome workflow yielded unexpected insights into the complex interplay between host genetics and viral/bacterial specific mechanisms, highlighted by a unique case of virally induced genetics (VIG) within one of these 27 patients. The power of RNA-Seq to study unique patient biology while investigating environmental contributions can be a critical tool moving forward for translational sciences applied to precision medicine.

Implementing an Oxygen Supplementation and Monitoring Protocol on Inpatient Pediatric Bronchiolitis: An Exercise in Deimplementation.

AIM: Our goal in this study is to evaluate the effectiveness of our oxygen (O2) protocol to reduce length of stay (LOS) for children hospitalized with bronchiolitis. METHODS: In this retrospective cohort study, the outcomes of children ≤ 24 months old that were admitted with bronchiolitis and placed on the O2 protocol were compared to historical controls. The primary outcome was hospital length of stay. Secondary outcomes were duration of O2 supplementation, rates of pediatric intensive care unit transfer, and readmission. RESULTS: Groups were not significantly different in age, gender, and rates of respiratory distress score assessment. Significantly more severely ill patients were in the O2 protocol group. There were no significant differences between control and O2 protocol groups with regard to mean LOS, rates of pediatric intensive care unit transfer, or seven-day readmission rates. By multiple regression analysis, the use of the O2 protocol was associated with a nearly 20% significant decrease in the length of hospitalization (p = 0.030). CONCLUSION: Use of O2 supplementation protocol increased LOS in the more ill patients with bronchiolitis but decreased overall LOS by having a profound effect on patients with mild bronchiolitis.

Red cell transfusions as an independent risk for mortality in critically ill children.

BACKGROUND: Severity of illness is an important consideration in making the decision to transfuse as it is the sicker patient that often needs a red cell transfusion. Red blood cell (RBC) transfusions could potentially have direct effects and interact with presenting illness by contributing to pathologies such as multi-organ dysfunction and acute lung injury thus exerting a considerable impact on overall morbidity and mortality. In this study, we examine if transfusion is an independent predictor of mortality, or if outcomes are merely a result of the initial severity as predicted by Pediatric Risk of Mortality (PRISM) III, Pediatric Index of Mortality (PIM2), and day 1 Pediatric Logistic Organ Dysfunction (PELOD) scores. METHODS: A single center retrospective study was conducted using data from a prospectively maintained transfusion database and center-specific data at our pediatric ICU between January 2009 and December 2012. Multivariate regression was used to control for the effects of clinical findings, therapy, and severity scores, with mortality as the dependent variable. Likelihood ratios and area under the curve were used to test the fidelity of severity scores by comparing transfused vs. non-transfused patients. RESULTS: There were 4975 admissions that met entry criteria. In multivariate analysis, PRISM III scores and serum hemoglobin were significant predictors of transfusion (p < 0.05). Transfused and non-transfused subjects were distinctly disparate, so multivariate regression was used to control for differences. Severity scores, age, volume transfused, and vasoactive agents were significantly associated with mortality whereas hemoglobin was not. A substantial number of transfusions (45 %) occurred in the first 24 h, and patients transfused later (24-48 h) were more likely to die compared to this earlier time point. Likelihood ratio testing revealed statistically significant differences in severity scoring systems to predict mortality in transfused vs. non-transfused patients. CONCLUSIONS: This study suggests that RBC transfusion is an important risk factor that is statistically independent of severity. The timing of transfusions that related strongest to mortality remained outside the purview of severity scoring, as these happened beyond the timing of data collection for most scoring systems.

RBC transfusions in children requiring intensive care admission after traumatic injury*.

OBJECTIVE: To describe packed RBC utilization patterns in trauma patients admitted to a PICU and study associated outcomes while controlling for severity. DESIGN: Retrospective cohort study. SETTING: The PICU of a tertiary care children's hospital. PATIENTS: All pediatric trauma patients admitted to Helen DeVos Children's Hospital PICU between June 2007 and July 2010, either directly from the emergency department or transferred from another institution. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 389 trauma patients, 107 patients (27.5%) transferred to the PICU were transfused with blood products. Of these transfusions, 81 were packed RBC transfusions and 26 were other blood products. Only 73 of the packed RBC transfusions had a documented time of transfusion: 17 (23.3%) were transfused prior to PICU admission, seven (9.5%) both before and after PICU, and 49 (67.1%) only after PICU admission. After adjusting for injury severity score, transfused patients had higher odds of needing mechanical ventilation (odds ratios, 9.2; 95% CI, 3.6-23.3) and higher risk of mortality (odds ratios, 8.6; 95% CI, 2.6-28.6), when compared with nontransfused patients. Mean age of packed RBC was 19.6 ± 9.3 days (mean ± SD). The impact of age of packed RBCs on mortality was examined as a categorical variable at 14, 21, and 28 days. Packed RBCs more than 28 days old (14/61 patients) were associated with longer lengths of stay (13 ± 12 vs 7 ± 6; p < 0.03), lower discharge Glasgow Coma Scale score (9 ± 6 vs 13 ± 4; p< 0.03), and more mortality (43% vs 13%; p < 0.02) when compared with blood less than 28 days old. CONCLUSIONS: In pediatric trauma patients, transfusion of packed RBC and use of older RBC units are associated with higher risk of adverse outcomes independent of injury severity.

The safety of propofol sedation for elective nonintubated esophagogastroduodenoscopy in pediatric patients.

OBJECTIVES: To evaluate the safety of deep sedation provided by pediatric intensivists for elective nonintubated esophagogastroduodenoscopy. DESIGN: Retrospective observational study. SETTING: The sedation program at the Helen DeVos Children's Hospital. PATIENTS: A 4-year retrospective analysis was done on all outpatient elective pediatric esophagogastroduodenoscopy procedures performed in an intensivist run sedation program. Safety was examined by reviewing the occurrence of minor and major adverse effects during esophagogastroduodenoscopy sedation. Interventions were studied and reported. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: During the study period, 12,447 sedations were performed by the pediatric sedation program for various procedures. Two thousand one hundred forty-seven patients received 2,325 sedations (18.6%) for esophagogastroduodenoscopies performed for various indications. During the same time period, 53 (one for every 40 esophagogastroduodenoscopy sedations) were screened, found unsuitable for nonintubated sedation, and referred for general anesthesia. There were 2,254 sedations with propofol, 65 methohexital, five ketamine, and one fentanyl/midazolam sedation. Propofol sedation proved safe with a 2.1% prevalence of minor adverse events and no major events. Methohexital, on the other hand, had higher rate (p < 0.001) of minor events and one patient developed an anaphylactic reaction to its use. Regression analysis showed that other sedative agents were 8.6 times more likely to be associated with complications than propofol (odds ratio, 8.6; 95% CI, 4.1-18.2; p < 0.001). CONCLUSIONS: This study demonstrates that deep sedation for elective esophagogastroduodenoscopies can be provided safely in the appropriately screened patient by nonanesthesiologist physicians in a sedation program. These data suggest that propofol is a safe and effective agent for esophagogastroduodenoscopy sedation.

Cost and safety of pediatric intensive care physician-placed broviac catheters.

OBJECTIVE: To compare the cost and safety of placement of Broviac catheters in children by pediatric intensivists in a sedation suite versus placement by pediatric surgeons in the operating room. DESIGN: Single-center retrospective analysis. SETTING: Pediatric sedation suite and operating rooms in a tertiary care children's hospital. PATIENTS: All pediatric patients with Broviac catheters placed (n = 253) at this institution over a 3-year period from 2007 to 2009. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We reviewed the charts of all pediatric patients with Broviac catheters placed, either by intensivists or surgeons, and compared cost and outcomes. Procedure safety was assessed and categorized into immediate, short-term (within 2 wk of procedure), and long-term outcomes. Anesthetic safety and billing data for the procedure were also collected. Among similar patient populations, immediate complications, such as pneumothorax, procedure failure (p > 0.999), and anesthetic complications (p = 0.60), were not significantly different. Short-term outcomes, including infection (p = 0.27) and catheter malfunction (p > 0.999), were not different. Long-term outcomes, including mean indwelling catheter days (p = 0.60) and removal due to catheter infection (p = 0.09), were not different between the groups. Overall cost of the procedure was significantly different: $7,031 (± $784) when performed by surgeons and $3,565 (± $311) when performed by intensivists (p < 0.001). CONCLUSIONS: Pediatric critical care physicians can place Broviac catheters as safely as pediatric surgeons and at a lower cost in a defined patient population.

Risk factors associated with pediatric intensive care unit admission and mortality after pediatric stem cell transplant: possible role of renal involvement.

BACKGROUND: Hematopoietic stem-cell transplant (HSCT) is associated with many risk factors for life-threatening complications. Post-transplant critical illness often requires admission to the pediatric intensive care unit (PICU). METHODS: A retrospective analysis was made on the risk factors associated with PICU admission and mortality of all HSCT patients at Helen DeVos Children's Hospital from October 1998 to November 2008. RESULTS: One hundred and twenty-four patients underwent HSCT, with 19 (15.3%) requiring 29 PICU admissions. Fifty patients received autologous, 38 matched sibling, and 36 matched un-related donor HSCT, with 10%, 13% and 25% of these patients requiring PICU admission, respectively (P=0.01). Among the HSCT patients, those who were admitted to the PICU were more likely to have renal involvement by either malignancy requiring nephrectomy or a post transplant complication increasing the likelihood of decreased renal function (21.1% vs. 4.8%, P=0.03). PICU admissions were also more likely to receive pre-transplant total body irradiation (52.6% vs. 27.6%, P=0.03). Among 29 patients with PICU admission, 3 died on day 1 after admission, and 5 within 30 days (a mortality rate of 17%). Thirty days after PICU admission, non-survivors had a higher incidence of respiratory failure and septic shock on admission compared with survivors (80% vs. 16.7%, P=0.01 and 80% vs. 4.2%, respectively, P=0.001). Two survivors with chronic renal failure underwent renal transplantation successfully. CONCLUSIONS: Total body irradiation and renal involvement are associated with higher risk for PICU admissions after HSCT in pediatric patients, while septic shock upon admission and post-admission respiratory failure are associated with mortality.

Respiratory Impairment after Early Red Cell Transfusion in Pediatric Patients with ALI/ARDS.

Introduction. In the first 48 hours of ventilating patients with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), a multipronged approach including packed red blood cell (PRBC) transfusion is undertaken to maintain oxygen delivery. Hypothesis. We hypothesized children with ALI/ARDS transfused within 48 hours of initiating mechanical ventilation would have worse outcome. The course of 34 transfused patients was retrospectively compared to 45 nontransfused control patients admitted to the PICU at Helen DeVos Children's Hospital between January 1st 2008 and December 31st 2009. Results. Mean hemoglobin (Hb) prior to transfusion was 8.2 g/dl compared to 10.1 g/dl in control. P/F ratio decreased from 135.4 ± 7.5 to 116.5 ± 8.8 in transfused but increased from 148.0 ± 8.0 to 190.4 ± 17.8 (P < 0.001) in control. OI increased in the transfused from 11.7 ± 0.9 to 18.7 ± 1.6 but not in control. Ventilator days in the transfused were 15.6 ± 1.7 versus 9.5 ± 0.6 days in control (P < 0.001). There was a trend towards higher rates of MODS in transfused patients; 29.4% versus 17.7%, odds ratio 1.92, 95% CI; 0.6-5.6 Fisher exact P < 0.282. Conclusion. This study suggests that early transfusions of patients with ALI/ARDS were associated with increased ventilatory needs.

Blood management in pediatric spinal deformity surgery: review of a 2-year experience.

BACKGROUND: Pediatric scoliosis surgery is associated with considerable blood loss and allogenic transfusions. Transfusions contribute to morbidities and cost. A perioperative pediatric blood management program was implemented at our institution. Patients received preoperative evaluation, cell salvage, topical hemostasis, antifibrinolytics, and hypotensive anesthesia. STUDY DESIGN AND METHODS: The study was a 2-year retrospective cohort review of the program's population from September 2007 through August 2009. RESULTS: A total of 110 scoliosis surgeries were performed with only 34 and 12% of the patients requiring preoperative oral iron and erythropoietin, respectively. Neuromuscular scoliosis patients had more repaired segments and a larger transfusion rate than idiopathic scoliosis patients (36% vs. 1.7%, p = 0.001). Transfused patients had more blood loss relative to their blood volume (p = 0.001) and blood loss was associated with higher Cobb angles (p = 0.04). Logistic regression revealed that blood loss (p = 0.001), number of segments fused (p = 0.004), and lower patient weight (p = 0.007) are associated with increased odds for transfusion. Twelve patients (10.9%) were identified with low von Willebrand activity with a trend toward higher blood losses (p = 0.07) with lower activity levels. CONCLUSION: Transfusion requirements in scoliosis patients are dependent on blood loss as determined by Cobb angles and number of segments fused relative to the patients' blood volume as determined by weight. Implementation of a blood management protocol resulted in a low transfusion rate and unexpectedly led to the preoperative diagnosis of a number of patients with low levels of von Willebrand activity.

Randomized controlled trial for intermittent versus continuous propofol sedation for pediatric brain and spine magnetic resonance imaging studies.

OBJECTIVES: Intermittent bolus propofol is an effective agent for pediatric magnetic resonance imaging sedation but requires constant vigilance and dose titration. Magnetic resonance imaging-compatible infusion pumps may make it possible to continuously infuse propofol, achieving a steady level of sedation at a lower total dose. This study investigates total propofol dose, recovery time, and magnetic resonance image quality in children receiving intermittent vs. continuously infused propofol sedation in children undergoing brain and spine magnetic resonance imaging studies. DESIGN: An open-label, prospective, randomized, controlled study. A single-blinded radiologist rated the quality of magnetic resonance images. SETTING: Children's hospital pediatric radiology sedation center. PATIENTS: One hundred seventy children age 1 month to 18 yrs undergoing deep sedation for brain, spine, or both brain and spine magnetic resonance imaging. INTERVENTIONS: After informed consent, patients were randomly assigned to two groups: group 1 (intermittent) received a propofol bolus of 2-4 mg/kg, followed by repeat boluses of 0.5-2 mg/kg/dose as needed. Group C (continuous) received a bolus of propofol 2-4 mg/kg, followed by a continuous infusion of 100 µg/kg/min with 1-mg/kg/dose boluses with drip titration to effect. MEASUREMENTS AND MAIN RESULTS: Patient demographics, sedation risk assessment, propofol dose, sedation recovery times, incidence of complications, and quality of the magnetic resonance imaging studies were measured. A total of 170 children were enrolled in the study, with 75 in group C and 95 in group I. Both groups were similar with regard to age, weight, gender, and magnetic resonance imaging study type. Group C required a lesser dose of propofol (132 ± 54 µg/kg/min) compared to (162 ± 74 µg/kg/min) in that required in group I (p = .018). There were no differences between the two groups with regard to quality of the imaging study, recovery time, or incidence of complications. CONCLUSIONS: Compared to intermittent bolus dosing, continuous propofol infusion provides lesser dose exposure without impacting recovery time or quality of the magnetic resonance imaging study.

Zero balance ultrafiltration (Z-BUF) in blood-primed CRRT circuits achieves electrolyte and acid-base homeostasis prior to patient connection.

Infants requiring CRRT present a unique challenge due to the large circuit volume to blood volume ratio. Blood priming is often used, but some patients can become unstable during the initiation of CRRT due to electrolyte and acid-base imbalance. We postulated that using Z-BUF we could normalize electrolytes and improve the acid base status of the prime prior to patient connection. To test this we set up a circuit using the Baxter BM-25 CRRT pump, a polysulfone or AN-69 membrane, and a three-way stopcock. The circuit was primed with a 60/40 mix of expired autologous donor pRBCs and 5% albumin. The modalities of CVVH, CVVHD, and CVVHDF were compared for relative efficacy. Electrolytes, lactate, pH, cytokines (TNF-alpha, IL-1beta, bradykinin, and IL-6) were measured. Plasma hemoglobin levels were also measured before and after the Z-BUF procedure. Bradykinin production and elimination in AN-69 membrane circuits were assessed. All lab values equilibrated by 35 minutes. All CRRT modalities were equally efficacious for Z-BUF. Cytokine production or significant hemolysis was not found. In addition, no bradykinin accumulation occurred in AN-69 membrane-containing circuits. We conclude that Z-BUF is a simple and effective way to normalize electrolyte and acid-base status in the CRRT circuit when blood priming is required.

Survival and functional outcome in pediatric traumatic brain injury: a retrospective review and analysis of predictive factors.

OBJECTIVE: The aim of this study was to evaluate the relationship of patient care variables to survival and functional outcome in the pediatric population with traumatic brain injury. DESIGN: Retrospective chart review. SETTING: A 16-bed pediatric critical care unit in an academic community children's hospital. PATIENTS: A total of 320 consecutive pediatric patients with traumatic brain injuries admitted to our pediatric critical care unit between 1992 and 1996. INTERVENTIONS: Patients were managed using our standard traumatic brain injury protocol. MEASUREMENTS AND MAIN RESULTS: A total of 230 patient variables encompassing demographic data, prehospital, emergency department, and pediatric critical care unit care were recorded. A total of 79 patients were severely injured, with admitting Glasgow Coma Scale scores of < or =10. There were 18 deaths. Only two patients survived without cognition. Ninety-five of 302 survivors required inpatient rehabilitation. Of these, 73 were old enough to be compared using FIMTM scores. At the time of discharge from rehabilitation, 52 patients (71%) were functioning independently, 20 (27%) were moderately dependent, and one patient was completely dependent. Analysis of variables with respect to survival revealed that an inability to maintain a cerebral perfusion pressure of > or =50 mm Hg on the first pediatric critical care unit day (p =.0002) and the presence of bradycardia in the emergency department (p =.0139) were the strongest factors associated with mortality. By using the regression equation generated from this model, we could correctly identify survivors and nonsurvivors with a predictive value of 94%. CONCLUSIONS: The ability to maintain a cerebral perfusion pressure of > or =50 mm Hg was the single most important predictor of traumatic brain injury survival in this study. This suggests that monitoring and optimizing cerebral perfusion pressure is critical to the management of these patients. The relationship between cognitive outcome and therapeutic interventions used to optimize cerebral perfusion pressure is unclear and requires further evaluation in a large prospective study.