Concurrent use of continuous kidney replacement therapy during extracorporeal membrane oxygenation: what pediatric nephrologists need to know-PCRRT-ICONIC practice points.

Extracorporeal membrane oxygenation (ECMO) provides temporary cardiorespiratory support for neonatal, pediatric, and adult patients when traditional management has failed. This lifesaving therapy has intrinsic risks, including the development of a robust inflammatory response, acute kidney injury (AKI), fluid overload (FO), and blood loss via consumption and coagulopathy. Continuous kidney replacement therapy (CKRT) has been proposed to reduce these side effects by mitigating the host inflammatory response and controlling FO, improving outcomes in patients requiring ECMO. The Pediatric Continuous Renal Replacement Therapy (PCRRT) Workgroup and the International Collaboration of Nephrologists and Intensivists for Critical Care Children (ICONIC) met to highlight current practice standards for ECMO use within the pediatric population. This review discusses ECMO modalities, the pathophysiology of inflammation during an ECMO run, its adverse effects, various anticoagulation strategies, and the technical aspects and outcomes of implementing CKRT during ECMO in neonatal and pediatric populations. Consensus practice points and guidelines are summarized. ECMO should be utilized in patients with severe acute respiratory failure despite the use of conventional treatment modalities. The Extracorporeal Life Support Organization (ELSO) offers guidelines for ECMO initiation and management while maintaining a clinical registry of over 195,000 patients to assess outcomes and complications. Monitoring and preventing fluid overload during ECMO and CKRT are imperative to reduce mortality risk. Clinical evidence, resources, and experience of the nephrologist and healthcare team should guide the selection of ECMO circuit.

Development and Validation of a Model for Endotracheal Intubation and Mechanical Ventilation Prediction in PICU Patients.

OBJECTIVES: To develop and externally validate an intubation prediction model for children admitted to a PICU using objective and routinely available data from the electronic medical records (EMRs). DESIGN: Retrospective observational cohort study. SETTING: Two PICUs within the same healthcare system: an academic, quaternary care center (36 beds) and a community, tertiary care center (56 beds). PATIENTS: Children younger than 18 years old admitted to a PICU between 2010 and 2022. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Clinical data was extracted from the EMR. PICU stays with at least one mechanical ventilation event (≥ 24 hr) occurring within a window of 1-7 days after hospital admission were included in the study. Of 13,208 PICU stays in the derivation PICU cohort, 1,175 (8.90%) had an intubation event. In the validation cohort, there were 1,165 of 17,841 stays (6.53%) with an intubation event. We trained a Categorical Boosting (CatBoost) model using vital signs, laboratory tests, demographic data, medications, organ dysfunction scores, and other patient characteristics to predict the need of intubation and mechanical ventilation using a 24-hour window of data within their hospital stay. We compared the CatBoost model to an extreme gradient boost, random forest, and a logistic regression model. The area under the receiving operating characteristic curve for the derivation cohort and the validation cohort was 0.88 (95% CI, 0.88-0.89) and 0.92 (95% CI, 0.91-0.92), respectively. CONCLUSIONS: We developed and externally validated an interpretable machine learning prediction model that improves on conventional clinical criteria to predict the need for intubation in children hospitalized in a PICU using information readily available in the EMR. Implementation of our model may help clinicians optimize the timing of endotracheal intubation and better allocate respiratory and nursing staff to care for mechanically ventilated children.

Fluid Balance Management Informs Renal Replacement Therapy Use During Pediatric Extracorporeal Membrane Oxygenation: A Survey Report From the Kidney Intervention During Extracorporeal Membrane Oxygenation Group.

Fluid overload (FO) and acute kidney injury (AKI) occur commonly in children supported with extracorporeal membrane oxygenation (ECMO). Continuous renal replacement therapy (CRRT) may be used to manage AKI and FO in children on ECMO. In 2012, our group surveyed ECMO centers to begin to understand the practice patterns around CRRT and ECMO. Since then, more centers are initiating ECMO for increasingly diverse indications and an increased volume of research quantifies the detrimental impacts of AKI and FO. We, therefore, investigated practice patterns of CRRT utilization during ECMO in children. A multi-point survey instrument was distributed to 116 international neonatal and pediatric ECMO centers. Sixty of 116 (51.7%) international neonatal and pediatric ECMO centers responded. All reports using CRRT on ECMO, compared with 75% from the 2012 survey. Eighty-five percent use CRRT to treat or prevent FO, an increased from 59%. The modality of CRRT therapy differed between in-line (slow continuous ultrafiltration, 84.4%) and machine-based (continuous venovenous hemodiafiltration, 87.3%) methods. Most (65%) do not have protocols for fluid management, AKI, or CRRT on ECMO. Trialing off CRRT is dictated by physician preference in 90% (54/60), with varying definitions of success. In this survey study, we found that CRRT use during pediatric ECMO has increased since 2012 with fluid management representing the predominant indication for initiation. Despite the expanded utilization of CRRT with ECMO, there remains significant practice variation in terms of method, modality, indication, the timing of initiation, fluid management, and discontinuation.

Timing of Fluid Overload and Association With Patient Outcome.

OBJECTIVES: To determine if the timing of excess fluid accumulation (fluid overload) is associated with adverse patient outcomes. DESIGN: Secondary analysis of a prospectively collected dataset. SETTING: PICU of a tertiary care hospital. PATIENTS: Children 3 months to 25 years old admitted to the PICU with expected length of stay greater than or equal to 48 hours. INTERVENTIONS: Patients were dichotomized by time of peak overload: peak fluid overload from ICU admission (Day0) to 48 hours (Day3-7) and peak fluid overload value after 48 hours of ICU admission, as well as time of first-time negative daily fluid balance: net fluid out greater than net fluid in for that 24-hour period. MEASUREMENTS AND MAIN RESULTS: There were 177 patients who met inclusion criteria, 92 (52%) male, with an overall mortality rate of 7% (n = 12). There were no differences in severity of illness scores or fluid overload on Day0 between peak fluid overload from ICU admission (Day0) to 48 hours (Day3-7) (n = 97; 55%) and peak fluid overload value after 48 hours of ICU admission (n = 80; 45%) groups. Peak fluid overload value after 48 hours of ICU admission was associated with a longer median ICU course (8 [4-15] vs 4 d [3-8 d]; p ≤ 0.001], hospital length of stay (18 [10-38) vs 12 [8-24]; p = 0.01], and increased risk of mortality (n = 10 [13%] vs 2 [2%]; χ2 = 7.6; p = 0.006]. ICU length of stay was also longer in the peak fluid overload value after 48 hours of ICU admission group when only patients with at least 7 days of ICU stay were analyzed (p = 0.02). Timing of negative fluid balance was also correlated with outcome. Compared with Day0-2, a negative daily fluid balance on Day3-7 was associated with increased length of mechanical ventilation (3 [1-7] vs 1 d [2-10 d]; p ≤ 0.001) and increased hospital (17 [10-35] vs 11 d [7-26 d]; p = 0.006) and ICU (7 [4-13] vs 4 d [3-7 d]; p ≤ 0.001) length of stay compared with a negative fluid balance between Day0-2. CONCLUSIONS: Our results show timing of fluid accumulation not just peak percentage accumulated is associated with patient outcome. Further exploration of the association between time and fluid accumulation is warranted.

CRISPR off-target analysis in genetically engineered rats and mice.

Despite widespread use of CRISPR, comprehensive data on the frequency and impact of Cas9-mediated off-targets in modified rodents are limited. Here we present deep-sequencing data from 81 genome-editing projects on mouse and rat genomes at 1,423 predicted off-target sites, 32 of which were confirmed, and show that high-fidelity Cas9 versions reduced off-target mutation rates in vivo. Using whole-genome sequencing data from ten mouse embryos, treated with a single guide RNA (sgRNA), and from their genetic parents, we found 43 off-targets, 30 of which were predicted by an adapted version of GUIDE-seq.

Use of plasma exchange in pediatric severe sepsis in children's hospitals.

Pediatric severe sepsis (PSS) is an important cause of death in children. Mortality increases in those with sepsis and multiple organ dysfunction syndrome (MODS). Plasma exchange (PE) has been used as an adjuvant therapy in sepsis, with trials demonstrating variable success. This observational retrospective cohort study aimed to characterize patient demographics, PE use, mortality and resource utilization in septic children from 43 children's hospitals from 2004 to 2012. Of 49,153 PSS cases, 1.8% utilized PE. Utilization increased to 4.8% in those with sepsis and MODS. Comorbidities affected 72-74% of patients. PE patients noted a longer hospitalization than PSS patients (39 vs 17 days). Overall mortality was 14.1% in PSS, increasing to 32.1% in PSS patients receiving PE. Mortality was 22% and 44.4% in PE patients without and with MODS respectively. Mortality decreased over the study period in both PE subgroups. In conclusion, PE utilization in PSS remained stable throughout the study period while PSS mortality decreased over time. Children utilizing PE had a higher associated mortality, but also greater comorbidities and MODS prevalence, likely representing a predilection towards use in more critically ill patients. These data can provide demographic and outcome results to inform future PE trials in sepsis.

BACE1 across species: a comparison of the in vivo consequences of BACE1 deletion in mice and rats.

Assessing BACE1 (ß-site APP cleaving enzyme 1) knockout mice for general health and neurological function may be useful in predicting risks associated with prolonged pharmacological BACE1 inhibition, a treatment approach currently being developed for Alzheimer's disease. To determine whether BACE1 deletion-associated effects in mice generalize to another species, we developed a novel Bace1-/- rat line using zinc-finger nuclease technology and compared Bace1-/- mice and rats with their Bace1+/+ counterparts. Lack of BACE1 was confirmed in Bace1-/- animals from both species. Removal of BACE1 affected startle magnitude, balance beam performance, pain response, and nerve myelination in both species. While both mice and rats lacking BACE1 have shown increased mortality, the increase was smaller and restricted to early developmental stages for rats. Bace1-/- mice and rats further differed in body weight, spontaneous locomotor activity, and prepulse inhibition of startle. While the effects of species and genetic background on these phenotypes remain difficult to distinguish, our findings suggest that BACE1's role in myelination and some sensorimotor functions is consistent between mice and rats and may be conserved in other species. Other phenotypes differ between these models, suggesting that some effects of BACE1 inhibition vary with the biological context (e.g. species or background strain).

High-dose cytarabine induction is well tolerated and active in patients with de novo acute myeloid leukemia older than 60 years.

BACKGROUND: High-dose cytarabine (HiDAC) is safe and very effective in younger patients with acute myeloid leukemia (AML), but it generally is not well tolerated in the elderly. METHODS: The authors explored the safety and tolerability of a modified HiDAC induction regimen consisting of 6 daily doses of cytarabine at 2 g/m(2) in combination with 3 daily doses of daunorubicin at 45 mg/m(2) in 59 consecutive patients aged >60 years who had de novo AML diagnosed between July 1996 and February 2005. RESULTS: The median patient age was 68 years (range, 60-86 years). The regimen was well tolerated. Infections were common and occurred in 39% of patients, but cerebellar toxicities occurred in only 7% of patients and were reversible. The day-30 induction-related mortality rate was 10%. Overall, 69% of patients achieved complete remissions (CR), and 80% received up to 3 consolidations with HiDAC. The median follow-up for surviving patients was 53 months (range, 17-114 months). The median overall survival was 15.3 months (range, 1-114 months), and the relapse-free survival was 13.8 months (range, 1-113 months). Survival for patients who achieved CR was 27 months (range, 2-114 months). CONCLUSIONS: The modified HiDAC regimen was well tolerated in patients aged >60 years with AML and was associated with low induction mortality and high rates of CR. Nevertheless, these high remissions still were associated with poor overall outcomes.

Prognostic significance of leukopenia at the time of diagnosis in acute myeloid leukemia.

We investigated the clinical significance of leukopenia at the time of diagnosis in a cohort of 225 patients with newly diagnosed acute myeloid leukemia (AML) at a single institution. Leukocyte count was treated as a continuous variable and, using a receiver operating characteristic curve (ROC), a cutoff of 3,600/µL had the best sensitivity and specificity for remission (complete remission [CR]), relapse-free survival [RFS], and overall survival [OS]). In a multivariable model, leukopenia at diagnosis had no effects on CR (hazard ratio [HR] = 2.02; confidence interval [CI], 0.9-4.3; P = .07), RFS (HR = 0.93; CI, 0.5-1.5; P = .8), or OS (HR = 1.05; CI, 0.7-1.5; P = .7). No differential expression of cell surface molecules (CD34, c-Kit, CXCR4, PECAM, VLA2, VLA-, VLA4, VLA5, and FLT3) was observed on simultaneously obtained marrow and blood blasts in the high- vs. low-leukocyte groups. We conclude that leukopenia at diagnosis carries no prognostic significance in AML.

Does pretreatment fluorescence in situ hybridization for BCR-ABL predict imatinib-associated hematologic toxicity in chronic myeloid leukemia?

Imatinib (IM)-associated myelosuppression is rare in gastrointestinal stromal cell tumors (<10%) but common in chronic myeloid leukemia (CML). Selective inhibition of predominantly Philadelphia chromosome (Ph+) driven hematopoiesis may explain myelosuppression in CML. In the absence of clinical methods to quantitate the Ph+/Ph- progenitor ratio, we hypothesized that the pre-IM percentage of BCR-ABL+ cells measured by fluorescence in situ hybridization (FISH) predicts for myelosuppression. FISH analyses performed within 30 days pre-IM 400 mg/day were analyzed in 89 patients with chronic phase CML at three institutions. Patients who developed grade ≥3 cytopenias had a higher percentage of positive FISH (90% vs. 83%; p = 0.02). Cytopenias lasted a median of 16 days, and all patients but one continued IM, achieved complete hematologic and cytogenetic remissions, and did not experience progression, with a follow-up of 61 months. In conclusion, IM-associated cytopenias are associated with a high pre-IM FISH, are reversible, and do not adversely affect outcomes.

Peripheral blood monitoring of chronic myeloid leukemia during treatment with imatinib, second-line agents, and beyond.

BACKGROUND: The current study was conducted to compare simultaneously obtained bone marrow (BM) cytogenetics (CTG), peripheral blood (PB) and BM fluorescence in situ hybridization (FISH), and quantitative real-time polymerase chain reaction (Q-PCR) for BCR-ABL1 in monitoring response to treatment with tyrosine kinase inhibitors and homoharringtonine (HHT) in patients with chronic myeloid leukemia (CML). METHODS: PB and BM FISH (n = 112 samples) and/or Q-PCR (n = 132 samples) for BCR-ABL1 were simultaneously obtained in 70 patients with Philadelphia chromosome-positive (Ph+) CML in chronic (68%), accelerated (16%), and blast phase (16%) before the initiation of therapy and during the course of treatment with imatinib (IM) (n = 40 patients), dasatinib (n = 20 patients), nilotinib (n = 4 patients), bosutinib (n = 18 patients), or HHT (n = 4 patients) for patients with newly diagnosed (n = 13 patients), IM-sensitive (n = 34 patients), IM-resistant (n = 30 patients), or IM-intolerant (n = 9 patients) disease. Eighteen patients were found to have Ph+ variants or karyotypic abnormalities in addition to the Ph+. RESULTS: Excellent correlations (r) were observed between PB and BM FISH (r = 0.95) and PB and BM Q-PCR (r = 0.87), as well as BM CTG and PB FISH (r = 0.89) and PB Q-PCR (r = 0.82). This correlation was not affected by the presence of the Ph+ variant or additional chromosomal abnormalities, the presence of ABL1 kinase domain mutations, phase of the disease, or treatment. CONCLUSIONS: PB FISH and Q-PCR appear to be reliable methods with which to monitor response to modern therapy in patients with all phases of CML.

Efficacy of dasatinib for the treatment of intractable chronic myeloid leukemia.

Dasatinib (DAS) is a well tolerated oral dual SRC inhibitor with remarkable activity against all phases of imatinib-resistant chronic myeloid leukemia (CML). This paper focuses on the activity of DAS in intractable CML, and reviews outcomes of patients enrolled on DAS clinical trials. Safety and tolerability as well as practical tips for management of side-effects, and drug interactions are included.