Acute Kidney Injury and Fluid Overload in Pediatric Cardiac Surgery

Purpose of review: Acute kidney injury (AKI) and fluid overload affect a large number of children undergoing cardiac surgery, and confers an increased risk for adverse complications and outcomes including death. Survivors of AKI suffer long-term sequelae. The purpose of this narrative review is to discuss the short and long-term impact of cardiac surgery associated AKI and fluid overload, currently available tools for diagnosis and risk stratification, existing management strategies, and future management considerations. Recent findings: Improved risk stratification, diagnostic prediction tools and clinically available early markers of tubular injury have the ability to improve AKI-associated outcomes. One of the major challenges in diagnosing AKI is the diagnostic imprecision in serum creatinine, which is impacted by a variety of factors unrelated to renal disease. In addition, many of the pharmacologic interventions for either AKI prevention or treatment have failed to show any benefit, while peritoneal dialysis catheters, either for passive drainage or prophylactic dialysis may be able to mitigate the detrimental effects of fluid overload. Summary: Until novel risk stratification and diagnostics tools are integrated into routine practice, supportive care will continue to be the mainstay of therapy for those affected by AKI and fluid overload after pediatric cardiac surgery. A viable series of preventative measures can be taken to mitigate the risk and severity of AKI and fluid overload following cardiac surgery, and improve care

Adherence to Daily Weights and Total Fluid Orders in the Pediatric Intensive Care Unit

Background: Fluid is central to the resuscitation of critically ill children. However, many pay limited attention to continued fluid accumulation. Fluid overload (FO) is associated with significant morbidity and mortality. The Volume Status Awareness Program (VSAP) is a multi-phase quality improvement initiative aimed at reducing iatrogenic FO. For baseline data, the authors examined a retrospective cohort of patients admitted to the pediatric intensive care unit. Methods: Cohort included diuretic-naive patients admitted to the pediatric intensive care unit at a tertiary care children's hospital in 2014. Furosemide-exposure was used to indicate provider-perceived FO. Variables included daily weight and total fluid (TF) orders, and their timing, frequency, and adherence. Implementation of VSAP phase 1 (bundle of interventions to promote consistent use of patient weights) occurred in June 2017. Results: Forty-nine patients met criteria. Five (10%) had daily weight orders, and 41 (84%) had TF orders-although 7 of these orders followed furosemide administration. Adherence to TF orders was good with 32 (78%) patients exceeding TF limits by 5% FO by day 1, and 22 (51%) had > 10% cumulative FO by day 3. Following phase 1 of the VSAP, the frequency of daily weight orders increased from 6% to 88%. Conclusions: In our institution, use of fluid monitoring tools is both inconsistent and infrequent. Early data from the VSAP project suggests simple interventions can modify ordering and monitoring practice, but future improvement cycles are necessary to determine if these changes are successful in reducing iatrogenic FO

Measurement of glomerular filtration rate reveals that subcapsular injection of shear‐thinning hyaluronic acid hydrogels does not impair kidney function in mice

The continued development of minimally invasive therapeutic implants, such as injectable hydrogels, necessitates the concurrent advancement of methods to best assess their biocompatibility via functional outcomes in vivo. Biomaterial implants have been studied to treat kidney disease; however, assessment of biocompatibility has been limited to biomarker and histological assessments. Techniques now exist to measure kidney function serially in vivo in murine studies via transcutaneous measurements of glomerular filtration rate (tGFR). In this study, adult male and female wild-type BalbC mice underwent right unilateral nephrectomy. The remaining solitary left kidney was allowed 4 weeks to recover via compensatory hypertrophy, after which subcapsular injection of either saline or shear-thinning hyaluronic acid hydrogel was performed. Serial tGFR measurements before and after treatment were used to assess the effect of hydrogel injection on kidney filtration. Urine and serum biomarkers of kidney function, and kidney histology were also quantified. Hydrogel injection did not affect kidney function, as assessed by tGFR. Results were in agreement with standard metrics of serum and urine biomarkers of injury as well as histological assessment of inflammation. The model developed provides a direct functional assessment of implant compatibility for the treatment of kidney disease and impact on kidney function

Immunotherapy with Injectable Hydrogels to Treat Obstructive Nephropathy

Hydrogels are gaining attention as injectable vehicles for delivery of therapeutics for a range of applications. We describe self-assembling and injectable Dock-and-Lock hydrogels for local delivery of interleukin-10 (IL-10) to abate the progression of inflammation and fibrosis that leads to chronic kidney disease. As monitored with a fluorescent tag, hydrogels degraded within a few days in vitro and matched IL-10 release profiles; however, hydrogels remained in the kidney for up to 30 days in vivo. A unilateral ureteral obstruction (UUO) mouse model was used to investigate in vivo outcomes after hydrogel injection and IL-10 delivery. Eight groups were investigated (7, 21, 35 days, n = 4): healthy, sham, healthy injected with mouse serum albumin (MSA), healthy + hydrogel, UUO, UUO + IL-10, UUO + hydrogel, UUO + hydrogel/IL-10. 15 μL of IL-10, hydrogel, or hydrogel/IL-10 was injected under the renal capsule 3 days after the UUO. Immunohistochemistry (IHC) was performed on paraffin sections to identify macrophages and apoptotic cells and trichrome staining was used to evaluate fibrosis. There were no significant differences in inflammatory markers between all control groups. With hydrogel delivery, macrophage infiltration and apoptosis were significantly reduced at days 21 and 35 compared to untreated animals. By day 35, IL-10 delivery via hydrogel reduced macrophage infiltration and apoptosis more than IL-10 injection alone. Fibrosis was decreased by day 35 in all treatment groups. This work supports the use of hydrogel delivery of IL-10 to treat chronic kidney disease

Urinary Tract Infections: Pediatric Primary Care Curriculum Podcast

Introduction: Demands on residents' time during training make it difficult for them to engage consistently with a primary care curriculum. In response to this, the emergency medicine and critical care fields have successfully utilized podcasting to the point where a recent study showed US emergency medicine residents ranked podcasts as the best use of their time for extracurricular education. Methods: We produced a 30-minute podcast on urinary tract infections from a primary care perspective, based on descriptors from Entrustable Professional Activity 4, "Manage acute common illnesses in the ambulatory setting." A moderator, a primary care pediatrician, and a pediatric nephrologist used a loose script of salient points, allowing for a natural evolution of the dialogue. The podcast was distributed to residents via email, along with a 7-question survey. Results: The survey was completed by 50 out of 84 residents. Ninety-two percent listened to all or part of the podcast, 98% found it educational, 93% enjoyed listening, and 74% felt more confident identifying and managing patients with possible urinary tract infections after listening. Ninety-six percent felt podcasts were a good alternative method for delivering this curriculum. One comment read, "This was great! It makes the information more accessible so that I can listen while working out or driving or just laying on the couch." Discussion: Based on this success, we are producing additional podcasts and will strive to keep them under 20 minutes, provide key summary points at the end, and improve ease of access by utilizing an RSS (rich site summary) feed

Risk Factors for Recurrent Acute Kidney Injury in Children Who Undergo Multiple Cardiac Surgeries: A Retrospective Analysis

Objectives: Determine the risk factors for repeated episodes of acute kidney injury in children who undergo multiple cardiac surgical procedures. Design: Single-center retrospective chart review. Setting: Cardiac ICU at a quaternary pediatric care center. Patients: Birth to 18 years who underwent at least two cardiac surgical procedures with cardiopulmonary bypass. Interventions: None. Measurements and main results: One-hundred eighty patients underwent two cardiac surgical procedures and 89 underwent three. Acute kidney injury was defined by the Kidney Disease: Improving Global Outcomes serum creatinine criteria. Acute kidney injury frequency was 26% (n = 46) after surgery 1, 20% (n = 36) after surgery 2, and 24% (n = 21) after surgery 3, with most acute kidney injury occurring on postoperative days 1 and 2. The proportion of patients with severe acute kidney injury increased from surgery 1 to surgery 3. Patients with acute kidney injury had a significantly longer duration of ventilation and length of stay after each surgery. The odds of acute kidney injury after surgery 3 was 2.40 times greater if acute kidney injury was present after surgery 1 or 2 (95% CI, 1.26-4.56; p = 0.008) after adjusting for confounders. The time between surgeries was not significantly associated with acute kidney injury (p = 0.85). Conclusions: In a heterogeneous population of pediatric patients with congenital heart disease undergoing multiple cardiopulmonary bypass surgeries, odds of acute kidney injury after a third surgery was increased by the presence of acute kidney injury after prior procedures. Time between surgery did not play a role in increasing odds of acute kidney injury. Further studies in a larger multicenter investigation are necessary to confirm these findings

Trends in the representation of women in the American Society of Pediatric Nephrology program at the Pediatric Academic Society annual meetings 2012–2021

IntroductionWomen are under-represented in virtually all fields of academic medicine. Even in pediatrics, a field that historically attracts a workforce with a majority of women physicians, substantial gender disparities persist in leadership positions. However, previous studies of gender representation in various academic settings are limited to small studies or aggregate pediatric subspecialties, thereby omitting important granularity within each subspecialty. No prior studies have investigated potential gender disparities in pediatric nephrology. The aim of this study is to determine the representation of women physicians in leadership and speaking roles in the annual American Society of Pediatric Nephrology (ASPN) meeting.MethodsData were analyzed from the 2012–2022 ASPN annual scientific meetings at the Pediatric Academic Society (PAS). Data were abstracted regarding gender and roles: speaker, chair/moderator, and lifetime achievement awardee. We performed a time series analysis using linear regression, with the year as the independent variable and the proportion of women as the dependent variable.ResultsOverall, there were statistically significant increases in the proportion of women speakers per year and percentage of women chairs or moderators. There were no specific trends noted for lifetime achievement awards and no statistically significant changes in the number of lifetime achievement awards.DiscussionWe found proportionate representations of gender representation with regards to speakers and chairs or moderators, although our data was limited by comparison to the American Board of Pediatrics (ABP) workforce cumulative “ever certified” data. The ABP data include a disproportionate representation of faculty who are men from earlier certification periods who may no longer be actively practicing pediatric nephrology

Acute Kidney Injury in Neonatal Encephalopathy: An Evaluation of the AWAKEN Database

Background: Acute kidney injury (AKI) is common in neonatal encephalopathy (NE) and is associated with worse outcomes. Our objectives were to determine the incidence, risk factors, and outcomes of AKI in infants with NE. Methods: We performed a retrospective analysis of infants ≥ 34 weeks' gestational age with a diagnosis of NE from the Analysis of Worldwide Acute Kidney injury Epidemiology in Neonates (AWAKEN) database. AKI was defined using the modified Kidney Disease Improving Global Outcomes criteria. Perinatal and postnatal factors were evaluated. Multivariate logistic and linear regressions were performed. Results: One hundred and thirteen patients with NE were included. 41.6% (47) developed AKI. Being born outside the admitting institution (OR 4.3; 95% CI 1.2-14.8; p = 0.02), intrauterine growth restriction (OR 10.3, 95% CI 1.1-100.5; p = 0.04), and meconium at delivery (OR 2.8, 95% CI 1.04-7.7; p = 0.04) conferred increased odds of AKI. After controlling for confounders, infants with AKI stayed in the hospital an average of 8.5 days longer than infants without AKI (95% CI 0.79-16.2 days; p = 0.03). Conclusions: In this multi-national analysis, several important perinatal factors were associated with AKI and infants with both NE and AKI had longer length of stay than NE alone. Future research aimed at early AKI detection, renoprotective management strategies, and understanding the long-term renal consequences is warranted in this high-risk group of patients