A Prospective Feasibility Study to Differentiate Sacral Neuromodulation Lead Electrode Configurations Using Motor and Sensory Thresholds and Locations of Sensation.

Background Accurate positioning and effective programming of sacral neuromodulation (SNM) relies upon the use of several acute stimulation measurements. While the clinical utility of these acute measurements including pelvic floor motor thresholds (PFMT), toe/leg motor thresholds (TMT), and sensory thresholds (ST), are widely accepted, their usefulness in quantitative research remains unclear. The purpose of this prospective study was to test these measurements and gauge their utility in future research. Methods Eight participants received Axonics SNM, 6 Medtronic Interstim II, and 2 Medtronic Micro SNM. PFMT was measured after implantation. ST and the location of sensation (LOS) were measured immediately postoperatively (PO), at pre-release from the surgery center (PR), and during a follow-up clinic visit (FU). Thresholds were compared across contact and time using linear mixed-effects models. Results Significant differences in PFMT were found across electrode configurations, with stimulation through proximal contacts exhibiting lower PFMT than distal configurations. ST displayed no significant differences across electrodes and showed minimal changes over time. LOS exhibited substantial variability across patients and periods. Conclusions Results suggest that PFMT were able to differentiate differences across electrode configurations that may be useful for future quantitative research. The lack of differences in ST and LOS across electrode configurations was interesting given the focus on these measurements clinically. Future testing is to confirm these limitations.

On some problems of Bayesian region construction with guaranteed coverages.

The general problem of constructing regions that have a guaranteed coverage probability for an arbitrary parameter of interest ψ ∈ Ψ is considered. The regions developed are Bayesian in nature and the coverage probabilities can be considered as Bayesian confidences with respect to the model obtained by integrating out the nuisance parameters using the conditional prior given ψ . Both the prior coverage probability and the prior probability of covering a false value (the accuracy) can be controlled by setting the sample size. These coverage probabilities are considered as a priori figures of merit concerning the reliability of a study while the inferences quoted are Bayesian. Several problems are considered where obtaining confidence regions with desirable properties have proven difficult to obtain. For example, it is shown that the approach discussed never leads to improper regions which has proven to be an issue for some confidence regions.

Conductance properties of the α9α10 nicotinic acetylcholine receptor of neonatal mouse inner and outer hair cells.

In the developing cochlea, just before the onset of hearing on postnatal day 12, the medial olivocochlear efferent axons in synaptic contact with the inner hair cells (IHCs) start withdrawing and new efferent synaptic connections are formed on the outer hair cells (OHCs), thereby progressing towards the adult pattern of medial olivocochlear efferent innervation. The synapses are inhibitory, calcium influx through the α9α10 nicotinic acetylcholine receptors (nAChRs) driving opening of calcium-dependent potassium channels. The nAChRs appear to function similarly in IHCs and OHCs, although with probable kinetic differences. Our aim was to assess their functional similarity in the neonatal mouse cochlea by making whole-cell recordings from both hair cell types between postnatal day 7 and 10 when nAChRs are expressed. ACh was applied to voltage-clamped hair cells by pressure-ejection from a pipette. The cells were dialysed with a Cs+-based solution designed to eliminate calcium-dependent potassium currents. There were differences in amplitude, voltage-sensitivity and reversal potential of the nAChR currents between IHCs and OHCs. There was also some indication that IHC nAChRs have slower activation and desensitization kinetics, although the relatively slow ACh application limited interpretation of this result. These differences, particularly concerning the reversal potential, might indicate the presence of different auxiliary protein subunits of the α9α10 receptor in neonatal IHCs and OHCs.

Relative Belief Inferences from Decision Theory.

Relative belief inferences are shown to arise as Bayes rules or limiting Bayes rules. These inferences are invariant under reparameterizations and possess a number of optimal properties. In particular, relative belief inferences are based on a direct measure of statistical evidence.

Use of low titer O whole blood in infants and young children undergoing cardiac surgery with cardiopulmonary bypass.

BACKGROUND: Low titer group O whole blood (LTOWB) is commonly used for severe bleeding in trauma patients. LTOWB may also benefit young children requiring cardiac surgery with cardiopulmonary bypass (CPB) at risk of severe bleeding. STUDY DESIGN AND METHODS: In this retrospective study, children <2 years old who underwent cardiac surgery with CPB were included. Comparisons were performed between those receiving component therapy (CT) versus those receiving LTOWB plus CT (LTOWB+CT). Outcomes included drainage tube (DT) output and total transfusion volumes. Optimization-based weighting was used for adjusted analyses between groups. RESULTS: There were 117 patients transfused with only CT and 127 patients transfused with LTOWB+CT. In the LTOWB+CT group, 66 were Group non-O and 61 were Group O. Total transfusion volumes given from the start of the operation until the first 24 h in the cardiac intensive care unit was a median (IQR) 41 (10, 93) mL/kg in the CT group and 48 (28, 77) mL/kg in the LTOWB+CT group, (p = .28). Median (IQR) DT output was 22 (15-32) in CT versus 22 (16-28) in LTOWB+CT groups, (p = .27). There were no differences in death, renal failure and a composite of death and renal failure between the two groups, but there were statistically fewer re-explorations for bleeding in the LTOWB+CT group (p < .001). CONCLUSIONS: The use of LTOWB appears to be safe in <2 years old undergoing cardiac surgery and may reduce re-explorations for severe bleeding. Large trials are needed to determine the efficacy and safety of LTOWB in this population with severe bleeding.

Relative biological effectiveness of clinically relevant photon energies for the survival of human colorectal, cervical, and prostate cancer cell lines.

Objective.Relative biological effectiveness (RBE) differs between radiation qualities. However, an RBE of 1.0 has been established for photons regardless of the wide range of photon energies used clinically, the lack of reproducibility in radiobiological studies, and outdated reference energies used in the experimental literature. Moreover, due to intrinsic radiosensitivity, different cancer types have different responses to radiation. This study aimed to characterize the RBE of clinically relevant high and low photon energiesin vitrofor three human cancer cell lines: HCT116 (colon), HeLa (cervix), and PC3 (prostate).Approach.Experiments were conducted following dosimetry protocols provided by the American Association of Physicists in Medicine. Cells were irradiated with 6 MV x-rays, an192Ir brachytherapy source, 225 kVp and 50 kVp x-rays. Cell survival post-irradiation was assessed using the clonogenic assay. Survival fractions were fitted using the linear quadratic model, and survival curves were generated for RBE calculations.Main results.Cell killing was more efficient with decreasing photon energy. Using 225 kVp x-rays as the reference, the HCT116 RBESF0.1for 6 MV x-rays,192Ir, and 50 kVp x-rays were 0.89 ± 0.03, 0.95 ± 0.03, and 1.24 ± 0.04; the HeLa RBESF0.1were 0.95 ± 0.04, 0.97 ± 0.05, and 1.09 ± 0.03, and the PC3 RBESF0.1were 0.84 ± 0.01, 0.84 ± 0.01, and 1.13 ± 0.02, respectively. HeLa and PC3 cells had varying radiosensitivity when irradiated with 225 and 50 kVp x-rays.Significance.This difference supports the notion that RBE may not be 1.0 for all photons through experimental investigations that employed precise dosimetry. It highlights that different cancer types may not have identical responses to the same irradiation quality. Additionally, the RBE of clinically relevant photons was updated to the reference energy of 225 kVp x-rays.

Inpatient Growth in Infants Requiring Pharmacologic Treatment for Neonatal Opioid Withdrawal Syndrome.

Aim: To assess inpatient growth parameter trajectories and to identify the type of opioid exposure and treatment characteristics influencing growth parameters of infants admitted to the newborn intensive care unit (NICU) for pharmacological treatment of neonatal opioid withdrawal syndrome (NOWS). Methods: Charts of term infants with NOWS admitted to NICU from 2012 to 2019, who received pharmacologic treatment, were reviewed. Intake (volume: mL/kg/day; calorie: kcal/kg/day) and growth parameter trajectories (weight, head circumference, and length) were analyzed based on the type of prenatal opioid exposure (short-acting opioids (SAOs), long-acting opioids (LAOs), and polysubstance), pharmacologic treatment, and sex. Growth measurement patterns over time were compared between groups using longitudinal mixed-effects models. Results: One hundred nineteen infants were included in the study with median birth weight Z-score of -0.19 at birth and decreased to a median of -0.72 at discharge. Exposure to SAO was associated with an increase in Z-scores nearing discharge across all growth parameters (Z-score for weight p = 0.03). Polysubstance exposure was associated with a decrease in Z-scores for length and head circumference throughout hospitalization. Infants with adjunct clonidine treatment had an increase in Z-score for weight trends. Male infants had a decrease in Z-scores for weight (male -0.96, female -0.59, interaction p = 0.06) and length (male -1.17, female -0.57, interaction p = 0.003) at Day 28. Despite the difference in growth trajectories, intake in terms of amount (mL/kg/day) and calorie intake (kcal/kg/day) was similar based on prenatal exposure, treatment, and sex. Conclusion: Infants with NOWS requiring pharmacologic treatment have a decrease in Z-scores for weight, length, and head circumference at birth and at hospital discharge. Infants with prenatal polysubstance exposure were at particular risk for poorer inpatient growth relative to infants exposed to SAO and LAO, indicated by lower Z-scores for length and occipital frontal circumference (OFC).

Disparities in Documentation: Evidence of Race-Based Biases in the Electronic Medical Record.

Personal implicit biases may contribute to inequitable health outcomes, but the mechanisms of these effects are unclear at a system level. This study aimed to determine whether stigmatizing subjective terms in electronic medical records (EMR) reflect larger societal racial biases. A cross-sectional study was conducted using natural language processing software of all documentation where one or more predefined stigmatizing words were used between January 1, 2019 and June 30, 2021. EMR from emergency care and inpatient encounters in a metropolitan healthcare system were analyzed, focused on the presence or absence of race-based differences in word usage, either by specific terms or by groupings of negative or positive terms based on the common perceptions of the words. The persistence ("stickiness") of negative and/or positive characterizations in subsequent encounters for an individual was also evaluated. Final analyses included 12,238 encounters for 9135 patients, ranging from newborn to 104 years old. White (68%) vs Black/African American (17%) were the analyzed groups. Several negative terms (e.g., noncompliant, disrespectful, and curse words) were significantly more frequent in encounters with Black/African American patients. In contrast, positive terms (e.g., compliant, polite) were statistically more likely to be in White patients' documentation. Independent of race, negative characterizations were twice as likely to persist compared with positive ones in subsequent encounters. The use of stigmatizing language in documentation mirrors the same race-based inequities seen in medical outcomes and larger sociodemographic trends. This may contribute to observed healthcare outcome differences by disseminating one's implicit biases to unknown future healthcare providers.

A lactobacilli-based inhaled live biotherapeutic product attenuates pulmonary neutrophilic inflammation.

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of prematurity. Exposure to noxious stimuli such as hyperoxia, volutrauma, and infection in infancy can have long-reaching impacts on lung health and predispose towards the development of conditions such as chronic obstructive pulmonary disease (COPD) in adulthood. BPD and COPD are both marked by lung tissue degradation, neutrophil influx, and decreased lung function. Both diseases also express a change in microbial signature characterized by firmicute depletion. However, the relationship between pulmonary bacteria and the mechanisms of downstream disease development has yet to be elucidated. We hypothesized that murine models of BPD would show heightened acetylated proline-glycine-proline (Ac-PGP) pathway and neutrophil activity, and through gain- and loss-of-function studies we show that Ac-PGP plays a critical role in driving BPD development. We further test a inhaled live biotherapeutic (LBP) using active Lactobacillus strains in in vitro and in vivo models of BPD and COPD. The Lactobacillus-based LBP is effective in improving lung structure and function, mitigating neutrophil influx, and reducing a broad swath of pro-inflammatory markers in these models of chronic pulmonary disease via the MMP-9/PGP (matrix metalloproteinase/proline-glycine-proline) pathway. Inhaled LBPs show promise in addressing common pathways of disease progression that in the future can be targeted in a variety of chronic lung diseases.

Neurocognitive Profile in Pediatric Kidney Transplant Candidates: Effects of Medical and Sociodemographic Factors.

Background: We evaluated the effects of kidney failure etiology, dialysis, and sociodemographic factors on the subdomains of intellectual functioning in pediatric kidney transplant candidates. Methods: This retrospective study included 78 pediatric kidney transplant candidates who completed a Wechsler Intelligence Scale assessment during pre-transplant neuropsychological evaluation between 1/1/2010 and 10/31/2022. Linear regression models were employed to examine the effects of kidney failure etiology, dialysis status, neighborhood area deprivation, and race on subdomains of intellectual functioning. Results: The mean scores of various intellectual functioning domains in pediatric kidney transplant candidates were significantly lower than in the general population (ps <0.001). After adjusting for covariates, patients with congenital anomalies of the kidney and urinary tract had significantly lower processing speed (M=85; 95% CI: 79-91) compared to patients with nephrotic syndrome (M=99; 95% CI: 90-107) and other etiologies (M=84; 95% CI: 78-90) (p=0.003). Patients living in high-level deprivation neighborhoods showed lower working memory performance (M=84, 95% CI: 77-91) than patients living in median-level (M=91, 95% CI: 87-95) and low-level (M=98, 95% CI: 92-104) neighborhood area deprivation (p=0.03). Patients from marginalized racial groups demonstrated lower verbal skills (M=80, 95% CI: 74-87) than White patients (M=92, 95% CI: 88-97) (p=0.02). Additionally, patients receiving dialysis showed higher reasoning skills (M=98, 95% CI: 90-104) than patients without dialysis (M= 90, 95% CI: 86-95) (p=0.04). Conclusions: Neurocognitive development in pediatric kidney transplant candidates is associated with medical and sociodemographic factors. Strategies to monitor, treat, and accommodate neurocognitive concerns need to be considered to optimize long-term medical and social outcomes.

Risk of Post-Acute Sequelae of SARS-CoV-2 Infection (PASC) Among Patients with Type 2 Diabetes Mellitus on Anti-Hyperglycemic Medications.

Background: Observed activity of metformin in reducing the risk of severe COVID-19 suggests a potential use of the anti-hyperglycemic in the prevention of post-acute sequelae of SARS-CoV-2 infection (PASC). We assessed the 3-month and 6-month risk of PASC among patients with type 2 diabetes mellitus (T2DM) comparing metformin users to sulfonylureas (SU) or dipeptidyl peptidase-4 inhibitors (DPP4i) users. Methods: We used de-identified patient level electronic health record data from the National Covid Cohort Collaborative (N3C) between October 2021 and April 2023. Participants were adults ≥ 18 years with T2DM who had at least one outpatient healthcare encounter in health institutions in the United States prior to COVID-19 diagnosis. The outcome of PASC was defined based on the presence of a diagnosis code for the illness or using a predicted probability based on a machine learning algorithm. We estimated the 3-month and 6-month risk of PASC and calculated crude and weighted risk ratios (RR), risk differences (RD), and differences in mean predicted probability. Results: We identified 5596 (mean age: 61.1 years; SD: 12.6) and 1451 (mean age: 64.9 years; SD 12.5) eligible prevalent users of metformin and SU/DPP4i respectively. We did not find a significant difference in risk of PASC at 3 months (RR = 0.86 [0.56; 1.32], RD = -3.06 per 1000 [-12.14; 6.01]), or at 6 months (RR = 0.81 [0.55; 1.20], RD = -4.91 per 1000 [-14.75, 4.93]) comparing prevalent users of metformin to prevalent users of SU/ DPP4i. Similar observations were made for the outcome definition using the ML algorithm. Conclusion: The observed estimates in our study are consistent with a reduced risk of PASC among prevalent users of metformin, however the uncertainty of our confidence intervals warrants cautious interpretations of the results. A standardized clinical definition of PASC is warranted for thorough evaluation of the effectiveness of therapies under assessment for the prevention of PASC.

Previous research suggests that metformin, due to its anti-viral, anti-inflammatory, and anti-thrombotic properties may reduce the risk of severe COVID-19. Given the shared etiology of COVID-19 and the post-acute sequelae of SARS-CoV-2 (PASC), and the proposed inflammatory processes of PASC, metformin may also be a beneficial preventive option. We investigated the benefit of metformin for PASC prevention in a population of type 2 diabetes mellitus patients with a COVID-19 diagnosis who were on metformin or two other anti-hyperglycemic medications prior to infection with SARS-CoV-2. Our results were consistent with a reduction in the risk of PASC with the use of metformin, however, the imprecise confidence intervals obtained warrants further investigation of this association of the potential beneficial effect of metformin for preventing PASC in patients with medication-managed diabetes.

Kidney transplant outcomes in children with simultaneous versus sequential heart-kidney transplants.

BACKGROUND: Heart transplant recipients frequently require kidney transplantation for concomitant advanced chronic kidney disease. Data on simultaneous (heart and kidney transplants performed simultaneously) versus sequential (heart transplant performed before kidney) heart-kidney transplants in children are limited. Herein, we compare kidney transplant outcomes between the two groups. METHOD: We used the Scientific Registry of Transplant Recipients to identify all pediatric (age <21 years) heart transplant recipients who also received a kidney transplant within 10 years of the heart transplant. We divided the study cohort into simultaneous heart-kidney and sequential heart-kidney recipients. We compared patient and death-censored graft survival using the Cox regression, adjusting for age at kidney transplant, sex, race, pre-transplant dialysis, donor type, and prior kidney transplant. We evaluated delayed graft function (defined as dialysis within the first week posttransplant) using logistic regression. RESULTS: Our analysis cohort included 165 recipients (86 simultaneous and 79 sequential). The incidence of delayed graft function was higher in simultaneous recipients (22.4 vs. 7.7%, p=0.017), but the difference lost statistical significance on multivariable analysis. We found no difference in patient survival (aHR 0.97; 95% CI 0.39, 2.41; p=0.95) after kidney transplant but higher death-censored kidney graft survival in sequential heart-kidney recipients compared with simultaneous heart-kidney recipients (aHR 4.26; 95% CI 1.21, 14.9; p=0.02). CONCLUSION: Sequential heart-kidney transplants are associated with higher death-censored kidney allograft survival in children compared with simultaneous heart-kidney transplants.

Consequences of low estimated glomerular filtration rate either before or early after kidney donation.

In the general population, decreases in glomerular filtration rate (GFR) are associated with subsequent development of chronic kidney disease (CKD), cardiovascular disease (CVD), and death. It is unknown if low estimated GFR (eGFR) before or early after kidney donation was also associated with these risks. One thousand six hundred ninety-nine living donors who had both predonation and early (4-10 weeks) postdonation eGFR were included. We studied the relationships between eGFR, age at donation, and the time to sustained eGFR<45 (CKD stage 3b) and <30 mL/min/1.73m2 (CKD stage 4), hypertension, diabetes mellitus (DM), CVD, and death. Median follow-up was 12 (interquartile range, 6-21) years. Twenty-year event rates were 5.8% eGFR<45 mL/min/1.73m2; 1.2% eGFR<30 mL/min/1.73m2; 29.0% hypertension; 7.8% DM; 8.0% CVD; and 5.2% death. The median time to eGFR<45 mL/min/1.73m2 (N = 79) was 17 years, and eGFR<30 mL/min/1.73m2 (N = 22) was 25 years. Both low predonation and early postdonation eGFR were associated with eGFR<45 mL/min/1.73m2 (P < .0001) and eGFR<30 mL/min/1.73m2 (P < .006); however, the primary driver of risk for all ages was low postdonation (rather than predonation) eGFR. Predonation and postdonation eGFR were not associated with hypertension, DM, CVD, or death. Low predonation and early postdonation eGFR are risk factors for developing eGFR<45 mL/min/1.73m2 (CKD stage 3b) and <30 mL/min/1.73m2 (CKD stage 4), but not CVD, hypertension, DM, or death.

Impact of the Reverse 2-Step Algorithm for Clostridioides difficile Testing in the Microbiology Laboratory on Hospitalized Patients.

Background: Multistep laboratory testing is recommended for the diagnosis of Clostridioides difficile infection (CDI). The aim of this study was to present the impact of multistep CDI diagnostic testing in an academic hospital system and evaluate the toxin B gene polymerase chain reaction (PCR) cycle threshold (Ct) values of PCR-positive tests. Methods: In October 2022, our system began reflex testing all PCR-positive stool samples with the C. DIFF QUIK CHEK COMPLETE (Techlab), an enzyme immunoassay-based test with results for the glutamate dehydrogenase antigen (GDH) and C difficile toxin A/B. Hospital-onset (HO) CDI and CDI antibiotic use before and after testing were tracked. Ct values were obtained from the Infectious Diseases Diagnostic Laboratory. Receiver operating curve analysis was used to examine the sensitivity and specificity for identifying GDH+/toxin+ and GDH-/toxin- at various Ct thresholds. Results: The HO-CDI rate decreased from 0.352 cases per 1000 patient-days to 0.115 cases per 1000 patient-days post-reflex testing (P < .005). Anti-CDI antibiotics use decreased, but the decrease was not commensurate with CDI rates following reflex testing. PCR+/GDH+/toxin+ samples had a lower mean Ct value than PCR+/GDH-/toxin- samples (23.3 vs 33.5, P < .0001). A Ct value of 28.65 could distinguish between those 2 groups. Fifty-four percent of PCR+/GDH+/toxin- samples had a Ct value below that cut-off, suggesting the possibility of CDI with a negative toxin test. Conclusions: Reflex testing for a laboratory diagnosis of CDI results in rapid, systemwide decreases in the rate of HO-CDI. Additional research is needed to distinguish CDI from C difficile colonization in patients with discordant testing.

Imaging the Granzyme Mediated Host Immune Response to Viral and Bacterial Pathogens In Vivo Using Positron Emission Tomography.

Understanding how the host immune system engages complex pathogens is essential to developing therapeutic strategies to overcome their virulence. While granzymes are well understood to trigger apoptosis in infected host cells or bacteria, less is known about how the immune system mobilizes individual granzyme species in vivo to combat diverse pathogens. Toward the goal of studying individual granzyme function directly in vivo, we previously developed a new class of radiopharmaceuticals termed "restricted interaction peptides (RIPs)" that detect biochemically active endoproteases using positron emission tomography (PET). In this study, we showed that secreted granzyme B proteolysis in response to diverse viral and bacterial pathogens could be imaged with [64Cu]Cu-GRIP B, a RIP that specifically targets granzyme B. Wild-type or germline granzyme B knockout mice were instilled intranasally with the A/PR/8/34 H1N1 influenza A strain to generate pneumonia, and granzyme B production within the lungs was measured using [64Cu]Cu-GRIP B PET/CT. Murine myositis models of acute bacterial (E. coli, P. aeruginosa, K. pneumoniae, and L. monocytogenes) infection were also developed and imaged using [64Cu]Cu-GRIP B. In all cases, the mice were studied in vivo using mPET/CT and ex vivo via tissue-harvesting, gamma counting, and immunohistochemistry. [64Cu]Cu-GRIP B uptake was significantly higher in the lungs of wild-type mice that received A/PR/8/34 H1N1 influenza A strain compared to mice that received sham or granzyme B knockout mice that received either treatment. In wild-type mice, [64Cu]Cu-GRIP B uptake was significantly higher in the infected triceps muscle versus normal muscle and the contralateral triceps inoculated with heat killed bacteria. In granzyme B knockout mice, [64Cu]Cu-GRIP B uptake above the background was not observed in the infected triceps muscle. Interestingly, live L. monocytogenes did not induce detectable granzyme B on PET, despite prior in vitro data, suggesting a role for granzyme B in suppressing their pathogenicity. In summary, these data show that the granzyme response elicited by diverse human pathogens can be imaged using PET. These results and data generated via additional RIPs specific for other granzyme proteases will allow for a deeper mechanistic study analysis of their complex in vivo biology.

New Morbidities During Critical Illness and Associated Risk of ICU Readmission: Virtual Pediatric Systems Cohort, 2017-2020.

OBJECTIVES: To describe change in Functional Status Scale (FSS) associated with critical illness and assess associated development of new morbidities with PICU readmission. DESIGN: Retrospective, cross-sectional cohort study using the Virtual Pediatric Systems (VPS; Los Angeles, CA) database. SETTING: One hundred twenty-six U.S. PICUs participating in VPS. SUBJECTS: Children younger than 21 years old admitted 2017-2020 and followed to December 2022. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 40,654 patients, 86.2% were classified as having good function or mild dysfunction before illness. Most patients did not have a change in their FSS category during hospitalization. Survival with new morbidity occurred most in children with baseline good/mild dysfunction (8.7%). Hospital mortality increased across categories of baseline dysfunction. Of 39,701 survivors, 14.2% were readmitted within 1 year. Median time to readmission was 159 days. In multivariable, mixed-effects Cox modeling, time to readmission was most associated with discharge functional status (hazard ratio [HR], 5.3 [95% CI, 4.6-6.1] for those with very severe dysfunction), and associated with lower hazard in those who survived with new morbidity (HR, 0.7 [95% CI, 0.6-0.7]). CONCLUSIONS: Development of new morbidities occurs commonly in pediatric critical illness, but we failed to find an association with greater hazard of PICU readmission. Instead, patient functional status is associated with hazard of PICU readmission.

Invasive haemodynamics predict outcomes in paediatric pulmonary artery hypertension.

BACKGROUND: Invasive haemodynamics are often performed for initiating and guiding pulmonary artery hypertension therapy. Little is known about the predictive value of invasive haemodynamic indices for long-term outcomes in children with pulmonary artery hypertension. We aimed to evaluate invasive haemodynamic data to help predict outcomes in paediatric pulmonary artery hypertension. METHODS: Patients with pulmonary artery hypertension who underwent cardiac catheterisation (2006-2019) at a single centre were included. Invasive haemodynamic data from the first cardiac catheterisation and clinical outcomes were reviewed. The combined adverse outcome was defined as pericardial effusion (due to right ventricle failure), creation of a shunt for pulmonary artery hypertension (atrial septal defect or reverse Pott's shunt), lung transplant, or death. RESULTS: Among 46 patients with a median [interquartile range (IQR)] age of 13.2 [4.1-44.7] months, 76% had CHD. Median mean pulmonary artery pressure was 37 [28-52] mmHg and indexed pulmonary vascular resistance was 6.2 [3.6-10] Woods units × m2. Median pulmonary artery pulsatility index was 4.0 [3.0-4.7] and right ventricular stroke work index was 915 [715-1734] mmHg mL/m2. After a median follow-up of 2.4 years, nine patients had a combined adverse outcome (two had a pericardial effusion, one underwent atrial level shunt, one underwent reverse Pott's shunt, and six died). Patients with an adverse outcome had higher systolic and mean pulmonary artery pressures, higher diastolic and transpulmonary pressure gradients, higher indexed pulmonary vascular resistance, higher pulmonary artery elastance, and higher right ventricular stroke work index (p < 0.05 each). CONCLUSION: Invasive haemodynamics (especially mean pulmonary artery pressure and diastolic pressure gradient) obtained at first cardiac catheterisation in children with pulmonary artery hypertension predicts outcomes.

Valacyclovir or valganciclovir for cytomegalovirus prophylaxis: A randomized controlled trial in adult and pediatric kidney transplant recipients.

BACKGROUND: Valganciclovir (valG), a cytomegalovirus (CMV) prophylactic agent, has dose-limiting side effects. The tolerability and effectiveness of valacyclovir (valA) as CMV prophylaxis is unknown. METHODS: We conducted a randomized, open-label, single-center trial of valA versus valG for all posttransplant CMV prophylaxis in adult and pediatric kidney recipients. Participants were randomly assigned to receive valA or valG. Primary endpoints were the incidence of CMV viremia and side-effect related drug reduction with secondary assessment of incidence of EBV viremia. RESULTS: Of the 137 sequential kidney transplant recipients enrolled, 26 % were positive and negative for CMV antibody in donor and recipient respectively. The incidence of CMV viremia (4 of 71 [6 %]; 8 of 67 [12 %] P = 0.23), time to viremia (P = 0.16) and area under CMV viral load time curve (P = 0.19) were not significantly different. ValG participants were significantly more likely to require side-effect related dose reduction (15/71 [21 %] versus 1/66 [2 %] P = 0.0003). Leukopenia was the most common reason for valG dose reduction and granulocyte-colony stimulating factor was utilized for leukopenia recovery more frequently (25 % in valG vs 5 % in valA: P = 0.0007). Incidence of EBV viremia was not significantly different. CONCLUSIONS: ValA has significantly less dose-limiting side effects than valG. In our study population, a significant increase in CMV viremia was not observed, in adults and children after kidney transplant, compared to valG. TRIAL REGISTRATION NUMBER: NCT01329185.

A machine learning approach to predict mortality due to immune-mediated thrombotic thrombocytopenic purpura.

Background: Mortality due to immune-mediated thrombotic thrombocytopenic purpura (iTTP) remains significant. Predicting mortality risk may potentially help individualize treatment. The French Thrombotic Microangiopathy (TMA) Reference Score has not been externally validated in the United States. Recent advances in machine learning technology can help analyze large numbers of variables with complex interactions for the development of prediction models. Objectives: To validate the French TMA Reference Score in the United States Thrombotic Microangiopathy (USTMA) iTTP database and subsequently develop a novel mortality prediction tool, the USTMA TTP Mortality Index. Methods: We analyzed variables available at the time of initial presentation, including demographics, symptoms, and laboratory findings. We developed our model using gradient boosting machine, a machine learning ensemble method based on classification trees, implemented in the R package gbm. Results: In our cohort (n = 419), the French score predicted mortality with an area under the receiver operating characteristic curve of 0.63 (95% CI: 0.50-0.77), sensitivity of 0.35, and specificity of 0.84. Our gradient boosting machine model selected 8 variables to predict acute mortality with a cross-validated area under the receiver operating characteristic curve of 0.77 (95% CI: 0.71-0.82). The 2 cutoffs corresponded to sensitivities of 0.64 and 0.50 and specificities of 0.76 and 0.87, respectively. Conclusion: The USTMA Mortality Index was acceptable for predicting mortality due to acute iTTP in the USTMA registry, but not sensitive enough to rule out death. Identifying patients at high risk of iTTP-related mortality may help individualize care and ultimately improve iTTP survival outcomes. Further studies are needed to provide external validation. Our model is one of many recent examples where machine learning models may show promise in clinical prediction tools in healthcare.