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1.
Neonatology ; 121(2): 203-212, 2024.
Article in English | MEDLINE | ID: mdl-38151013

ABSTRACT

INTRODUCTION: Nephrotoxic medication (NTM) exposure is commonly associated with acute kidney injury (AKI) in the neonatal intensive care unit (NICU). Baby Nephrotoxic Injury Negated by Just-in-Time Action (NINJA) is a quality improvement program that assesses for AKI in those exposed to NTM with daily serum creatinine (SCr) levels. However, blood draws for SCr are invasive and have clinical disadvantages. Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is a promising indicator of AKI. We tested the hypothesis that uNGAL could reliably screen for NTM-AKI in the Baby NINJA program. METHODS: This two-center prospective study screened 174 NICU subjects, of whom 148 met screening criteria from January 29, 2019, to September 18, 2020. Daily SCr and urine samples were obtained for up to 7 days of NTM exposure plus 2 days after exposure ended or end of AKI. AKI was defined by a SCr rise of 50% from baseline. The highest uNGAL obtained was evaluated to determine its relationship to the diagnosis of AKI. Logistic regression models were used to determine optimal uNGAL cutoffs. RESULTS: The negative predictive value of a uNGAL value ≥250 ng/mL was 96.8% (95% CI = 93.3-100%). Urine NGAL ≥400 ng/mL demonstrated the highest ROC-AUC value of 0.72 with a positive likelihood risk for AKI of 2.76 (1.39-4.13). DISCUSSION/CONCLUSION: We propose that uNGAL could be used to screen for NTM-AKI and thus replace many blood draws needed in those exposed to NTM. The ideal uNGAL threshold requires further investigation in infants.


Subject(s)
Acute Kidney Injury , Intensive Care Units, Neonatal , Infant , Infant, Newborn , Humans , Lipocalin-2/urine , Creatinine , Prospective Studies , Biomarkers , Acute Kidney Injury/chemically induced , Acute Kidney Injury/diagnosis
3.
Nat Commun ; 12(1): 4757, 2021 Aug 06.
Article in English | MEDLINE | ID: mdl-34362917

ABSTRACT

The plate tectonic cycle produces chemically distinct mid-ocean ridge basalts and arc volcanics, with the latter enriched in elements such as Ba, Rb, Th, Sr and Pb and depleted in Nb owing to the water-rich flux from the subducted slab. Basalts from back-arc basins, with intermediate compositions, show that such a slab flux can be transported behind the volcanic front of the arc and incorporated into mantle flow. Hence it is puzzling why melts of subduction-modified mantle have rarely been recognized in mid-ocean ridge basalts. Here we report the first mid-ocean ridge basalt samples with distinct arc signatures, akin to back-arc basin basalts, from the Arctic Gakkel Ridge. A new high precision dataset for 576 Gakkel samples suggests a pervasive subduction influence in this region. This influence can also be identified in Atlantic and Indian mid-ocean ridge basalts but is nearly absent in Pacific mid-ocean ridge basalts. Such a hemispheric-scale upper mantle heterogeneity reflects subduction modification of the asthenospheric mantle which is incorporated into mantle flow, and whose geographical distribution is controlled dominantly by a "subduction shield" that has surrounded the Pacific Ocean for 180 Myr. Simple modeling suggests that a slab flux equivalent to ~13% of the output at arcs is incorporated into the convecting upper mantle.

4.
J Pediatr Urol ; 14(6): 567.e1-567.e6, 2018 12.
Article in English | MEDLINE | ID: mdl-30177384

ABSTRACT

BACKGROUND: Children with neurogenic bladders who require clean intermittent catheterization (CIC) frequently have bacteriuria. However, there is no consensus on what constitutes at urinary tract infection (UTI) in this population. Multiple subspecialists are often involved in the management of these patients, although they are frequently cared for by hospitalists when admission is required. OBJECTIVE: The objective of this study was to describe the variability in opinion between subspecialists in the diagnosis of a UTI in CIC-dependent children. STUDY DESIGN: A scenario-based survey was distributed to physicians in the divisions of urology, nephrology, and hospital medicine at a single free-standing children's hospital. Respondents rated their degree of confidence on whether a specific scenario represented UTI or colonization on an 11-point Likert Scale. Median responses were compared with the Kruskal-Wallis test with pair-wise comparisons. RESULTS: Back/flank pain, abdominal pain, and vomiting were the most common symptoms that were suggestive of a UTI in a non-febrile child. There was no single symptom chosen that was the most suggestive of a UTI in CIC-dependent child. There was significant variability between specialists in the diagnosis of UTI in specific clinical scenarios on the survey. Hospitalists were significantly less confident about the diagnosis of a UTI than urologists in two of the clinical scenarios. CONCLUSIONS: Standardization and implementation of consensus criteria for UTI in this high-risk population is needed.


Subject(s)
Practice Patterns, Physicians' , Urinary Tract Infections/diagnosis , Child , Health Care Surveys , Hospital Medicine , Humans , Intermittent Urethral Catheterization , Medicine , Nephrology , Urinary Bladder, Neurogenic/complications , Urinary Tract Infections/etiology , Urinary Tract Infections/therapy , Urology
5.
J Pediatr Urol ; 13(5): 488.e1-488.e5, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28284733

ABSTRACT

BACKGROUND: Children who require clean intermittent catheterization (CIC) frequently have positive urine cultures. However, diagnosing a urinary tract infection (UTI) can be difficult, as there are no standardized criteria. Routine urinalysis (UA) has good predictive accuracy for UTI in the general pediatric population, but data are limited on the utility of routine UA in the population of children who require CIC. OBJECTIVE: To determine the utility of UA parameters (e.g. leukocyte esterase, nitrites, and pyuria) to predict UTI in children who require CIC, and identify a composite UA that has maximal predictive accuracy for UTI. METHODS: A cross-sectional study of 133 children who required CIC, and had a UA and urine culture sent as part of standard of care. Patients in the no-UTI group all had UA and urine cultures sent as part of routine urodynamics, and were asymptomatic. Patients included in the UTI group had growth of ≥50,000 colony-forming units/ml of a known uropathogen on urine culture, in addition to two or more of the following symptoms: fever, abdominal pain, back pain, foul-smelling urine, new or worse incontinence, and pain with catheterization. Categorical data were compared using Chi-squared test, and continuous data were compared with Student's t-test. Sensitivity, specificity, and positive and negative predictive values were calculated for individual UA parameters, as well as the composite UA. Logistic regression was performed on potential composite UA models to identify the model that best fit the data. RESULTS: There was a higher proportion of patients in the no-UTI group with negative leukocyte esterase compared with the UTI group. There was a higher proportion of patients with UTI who had large leukocyte esterase and positive nitrites compared with the no-UTI group (Summary Figure). There was no between-group difference in urinary white blood cells. Positive nitrites were the most specific (84.4%) for UTI. None of the parameters had a high positive predictive value, while all had high negative predictive values. The composite model with the best Akaike information criterion was >10 urinary white blood cells and either moderate or large leukocyte esterase, which had a positive predictive value of 33.3 and a negative predictive value of 90.4. CONCLUSION: Routine UA had limited sensitivity, but moderate specificity, in predicting UTI in children who required CIC. The composite UA and moderate or large leukocyte esterase both had good negative predictive values for the outcome of UTI.


Subject(s)
Urinalysis/statistics & numerical data , Urinary Bladder, Neurogenic/therapy , Urinary Catheterization/methods , Urinary Tract Infections/diagnosis , Adolescent , Chi-Square Distribution , Child , Child, Preschool , Cohort Studies , Cross-Sectional Studies , Diagnostic Tests, Routine , Female , Humans , Logistic Models , Male , Predictive Value of Tests , Risk Assessment , Sensitivity and Specificity , Urinary Bladder, Neurogenic/diagnosis , Urinary Tract Infections/prevention & control , Urine/microbiology
6.
Article in English | MEDLINE | ID: mdl-30637336

ABSTRACT

Preterm infants are at risk for acute kidney injury (AKI) for multiple reasons. Reports on the frequency and timeline of iatrogenic renal insults and potential consequences are limited. Our objectives are to estimate the prevalence and timing of exposure to nephrotoxic medications, and assess the association of these nephrotoxic medications with AKI in preterm infants. We performed a retrospective chart review of infants <30 weeks postmenstrual age and/or <1500 g birth weight admitted to the neonatal intensive care units at Cincinnati Children's Hospital Medical Center and University of Cincinnati Medical Center from 2011 to 2014. We queried the electronic health record for exposures to nephrotoxic medications and/or radiologic contrast media and correlated to serum creatinine concentration proximate to the exposure. Using the Kidney Disease Improving Global Outcomes (KDIGO) creatinine criteria, we assessed the AKI rate associated with the exposures. The cohort included 276 preterm infants. 233 (84%) received nephrotoxicity-associated medications. Antibiotics were the most common type (80%). AKI occurred in 9% of infants and was associated with exposure to a nephrotoxic medication. In a forward stepwise logistical regression, birth weight (OR: 0.995 (95% CI: 0.991-0.998), p=0.004) and number of exposures (OR: 1.83 (95% CI: 1.33-2.53), p=0.0002) were predictive of AKI. Nephrotoxic medication exposure increased the odds of AKI in preterm and low birth weight infants. Future prospective surveillance through the electronic health record in addition to routine serum creatinine monitoring may reduce the rate of exposure and subsequent AKI.

7.
Appl Clin Inform ; 5(2): 313-33, 2014.
Article in English | MEDLINE | ID: mdl-25024752

ABSTRACT

BACKGROUND: Nephrotoxic medication-associated acute kidney injury (NTMx-AKI) is a costly clinical phenomenon and more common than previously recognized. Prior efforts to use technology to identify AKI have focused on detection after renal injury has occurred. OBJECTIVES: Describe an approach and provide a technical framework for the creation of risk-stratifying AKI triggers and the development of an application to manage the AKI trigger data. Report the performance characteristics of those triggers and the refinement process and on the challenges of implementation. METHODS: Initial manual trigger screening guided design of an automated electronic trigger report. A web-based application was designed to alleviate inefficiency and serve as a user interface and central workspace for the project. Performance of the NTMx exposure trigger reports from September 2011 to September 2013 were evaluated using sensitivity (SN), specificity (SP), positive and negative predictive values (PPV, NPV). RESULTS: Automated reports were created to replace manual screening for NTMx-AKI. The initial performance of the NTMx exposure triggers for SN, SP, PPV, and NPV all were ≥0.78, and increased over the study, with all four measures reaching ≥0.95 consistently. A web-based application was implemented that simplifies data entry and couriering from the reports, expedites results viewing, and interfaces with an automated data visualization tool. Sociotechnical challenges were logged and reported. CONCLUSION: We have built a risk-stratifying system based on electronic triggers that detects patients at-risk for NTMx-AKI before injury occurs. The performance of the NTMx-exposed reports has neared 100% through iterative optimization. The complexity of the trigger logic and clinical workflows surrounding NTMx-AKI led to a challenging implementation, but one that has been successful from technical, clinical, and quality improvement standpoints. This report summarizes the construction of a trigger-based application, the performance of the triggers, and the challenges uncovered during the design, build, and implementation of the system.


Subject(s)
Acute Kidney Injury/chemically induced , Drug-Related Side Effects and Adverse Reactions , Electronic Health Records , Medical Informatics/methods , Algorithms , Child , Humans , Internet , Research Report , Risk Assessment
8.
Clin Pharmacol Ther ; 96(2): 159-61, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24810205

ABSTRACT

Acute kidney injury requiring continuous renal replacement therapy is common, costly, and associated with mortality rates of up to 60%. Accurate pharmacokinetic data are essential to developing rational individualized dosing strategies and providing optimal care to these patients, yet few such data exist, probably due in part to an absence of regulatory guidance on the issue. The Kidney Health Initiative is working with stakeholders to propose strategies to address this in a standardized manner.


Subject(s)
Acute Kidney Injury/drug therapy , Critical Illness/therapy , Practice Guidelines as Topic/standards , Renal Replacement Therapy/standards , Societies, Medical/standards , United States Food and Drug Administration/standards , Acute Kidney Injury/epidemiology , Anti-Bacterial Agents/administration & dosage , Critical Illness/epidemiology , Dose-Response Relationship, Drug , Humans , United States/epidemiology
9.
Hernia ; 15(3): 339-42, 2011 Jun.
Article in English | MEDLINE | ID: mdl-20364284

ABSTRACT

The optimal therapeutic approach to a patient who has a large incarcerated inguinal hernia and an abdominal aortic aneurysm (AAA) of significant size is controversial. Here we report a case of a patient who presented with a giant incarcerated inguinal hernia who was found to have an 8-cm AAA. Three surgical options were considered: (1) perform open AAA repair first, followed by hernia repair a few weeks later to allow for recovery, (2) perform hernia repair first followed by AAA repair a few weeks later, or (3) perform both simultaneously as a combination procedure. We successfully performed hernia repair first, followed by open AAA repair as a separate procedure at a later date. We believe that a two-stage approach, performing hernia repair first, is the safest approach to surgical repair of an incarcerated hernia in a patient with an asymptomatic AAA that requires open repair.


Subject(s)
Aortic Aneurysm, Abdominal/surgery , Hernia, Inguinal/surgery , Aged , Aortic Aneurysm, Abdominal/complications , Aortic Aneurysm, Abdominal/diagnostic imaging , Hernia, Inguinal/complications , Hernia, Inguinal/diagnostic imaging , Humans , Male , Radiography , Scrotum/diagnostic imaging
10.
Am J Transplant ; 10(7): 1677-85, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20642689

ABSTRACT

The measurement properties of the newly developed Pediatric Quality of Life Inventory (PedsQL) 3.0 Transplant Module in pediatric solid organ transplant recipients were evaluated. Participants included pediatric recipients of liver, kidney, heart and small bowel transplantation who were cared for at seven medical centers across the United States and their parents. Three hundred and thirty-eight parents of children ages 2-18 and 274 children ages 5-18 completed both the PedsQL 4.0 Generic Core Scales and the Transplant Module. Findings suggest that child self-report and parent proxy-report scales on the Transplant Module demonstrated excellent reliability (total scale score for child self-report alpha= 0.93; total scale score for parent proxy-report alpha= 0.94). Transplant-specific symptoms or problems were significantly correlated with lower generic HRQOL, supporting construct validity. Children with solid organ transplants and their parents reported statistically significant lower generic HRQOL than healthy children. Parent and child reports showed moderate to good agreement across the scales. In conclusion, the PedsQL Transplant Module demonstrated excellent initial feasibility, reliability and construct validity in pediatric patients with solid organ transplants.


Subject(s)
Health Status , Organ Transplantation/physiology , Quality of Life , Adolescent , Adult , Child , Child, Preschool , Feasibility Studies , Female , Humans , Male , Organ Transplantation/psychology , Parents/psychology , Psychology, Child , Reproducibility of Results , United States
11.
Int J Artif Organs ; 30(4): 321-4, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17520569

ABSTRACT

Hemodialysis remains the only life sustaining maintenance renal replacement therapy option for children who cannot undergo expeditious renal transplantation or who are not medical candidates for peritoneal dialysis. Provision of maintenance hemodialysis to small children entails many challenges, which arise from the limited choices for appropriately sized disposable dialysis treatment components. The dialysis extracorporeal circuit volume, comprised of the blood tubing and dialyzer, should be low enough to prevent hypotension and prevent the need for repeated blood transfusions. We performed a market acceptance evaluation of the Polyflux 6H dialyzer (0.6 m2 membrane surface area; Gambro Renal Products, Lakewood, Colorado) in six pediatric patients (3 male, 3 female, mean weight 24.4+6.5 kg, mean age 10.3+3.8 yrs). We found that the Polyflux 6H Dialyzer provided a trend for improved clearance compared to Fresenius F3 and F4 dialyzers. We found that the Polyflux 6H Dialyzer provided adequate clearance for children up to 24 kg in size and is a suitable dialyzer choice for patients 13 to 26 kg in size.


Subject(s)
Renal Dialysis/instrumentation , Adolescent , Body Weight , Carbon Dioxide/blood , Child , Child, Preschool , Disposable Equipment , Equipment Design , Female , Humans , Male , Membranes, Artificial , Nylons , Polymers , Potassium/blood , Povidone , Renal Dialysis/methods , Renal Dialysis/standards , Sodium/blood , Sulfones , Surface Properties , Treatment Outcome , Ultrafiltration , Urea/blood
12.
Kidney Int ; 71(10): 1028-35, 2007 May.
Article in English | MEDLINE | ID: mdl-17396113

ABSTRACT

A classification system has been proposed to standardize the definition of acute kidney injury in adults. These criteria of risk, injury, failure, loss, and end-stage renal disease were given the acronym of RIFLE. We have modified the criteria based on 150 critically ill pediatric RIFLE (pRIFLE) patients to assess acute kidney injury incidence and course along with renal and/or non-renal comorbidities. Of these children, 11 required dialysis and 24 died. Patients without acute kidney injury in the first week of intensive care admission were less likely to subsequently develop renal Injury or Failure; however, 82% of acute kidney injury occurred in this initial week. Within this group of 123 children, 60 reached pRIFLEmax for Risk, 32 reached Injury, and 31 reached Failure. Acute kidney injury during admission was an independent predictor of intensive care; hospital length of stay and an increased risk of death independent of the Pediatric Risk of Mortality (PRISM II) score (odds ratio 3.0). Our results show that a majority of critically ill children develop acute kidney injury by pRIFLE criteria and do so early in the course of intensive care. Acute kidney injury is associated with mortality and may lead to increased hospital costs. We suggest that the pRIFLE criteria serves to characterize the pattern of acute kidney injury in critically ill children.


Subject(s)
Critical Illness , Diagnostic Techniques, Urological , Kidney Diseases/diagnosis , Acute Disease , Adolescent , Adult , Child , Child, Preschool , Creatinine/blood , Diuresis , Female , Hospitalization , Humans , Incidence , Infant , Infant, Newborn , Intensive Care Units, Pediatric , Kidney/physiopathology , Kidney Diseases/epidemiology , Kidney Diseases/mortality , Kidney Diseases/physiopathology , Length of Stay , Male , Prospective Studies , Recovery of Function
13.
Int J Artif Organs ; 30(12): 1116-21, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18203074

ABSTRACT

PURPOSE: Well-functioning vascular access is essential for the provision of adequate CRRT. However, few data exist to describe the effect of catheter size or location on CRRT performance in the pediatric population. METHODS: Data for vascular access site, size, and location, as well as type of anticoagulant used and patient demographic data were gathered from the ppCRRT registry. Kaplan-Meier curves were generated and then analyzed by log-rank test or Cox Proportional Hazards model. RESULTS: Access diameter was found to significantly affect circuit survival. None of the 5 French catheters lasted longer than 20 hours. Seven and 9 French, but not 8 French, catheters fared worse than larger diameter catheters (p=0.002). Circuits associated with internal jugular access survived longer than subclavian or femoral access associated circuits (p<0.05). Circuit survival was also found to be favorably associated with the CVVHD modality (p<0.001). CONCLUSIONS: Functional CRRT circuit survival in children is favored by larger catheter diameter, internal jugular vein insertion site and CVVHD. For patients requiring catheter diameters less than 10 French, CRRT circuit survival might be optimized if internal jugular vein insertion is feasible. Conversely, when a vascular access site other than the internal jugular vein is most prudent, consideration should be given to using the largest diameter catheter appropriate for the size of the child. The CVVHD modality was associated with longer circuit survival, but the mechanism by which this occurs is unclear.


Subject(s)
Catheterization, Central Venous , Catheterization, Peripheral , Hemofiltration , Kidney Failure, Chronic/therapy , Registries , Renal Dialysis , Adolescent , Adult , Catheters, Indwelling , Child , Child, Preschool , Cohort Studies , Humans , Infant , Infant, Newborn , Proportional Hazards Models , United States
14.
Kidney Int ; 69(1): 184-9, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16374442

ABSTRACT

Few data exist regarding the long-term sequelae of acute renal failure (ARF), and these studies are limited to a few renal conditions. We aim to assess the 3-5-year survival and incidence of renal injury in children who previously developed ARF of varying causes. We queried parents, physicians, and hospital/state vital statistics records to find patient survival in 174 children who previously had ARF and survived to hospital discharge. We assessed the following in 29 children for residual renal injury: (a) microalbuminuria, (b) glomerular filtration rate (GFR) by Schwartz formula, (c) hypertension, and (d) hematuria. The 3-5-year survival of children with ARF who survived to hospital discharge was 139/174 (79.9%). Most deaths (24/35 (68.5%)) occurred within 12 months after initial hospitalization. Combining those who died during initial hospitalization and in subsequent 3-5 years, the overall survival rate was 139/245 (56.8%). In all, 16 children progressed to end-stage renal disease; thus, renal survival was 127/173 (91%). Those with primary renal/urologic conditions had lower renal survival than others (24/35 (68.6%) vs 134/139 (96.4%); P<0.0001). Among the 29 patients assessed for long-term sequelae at 3-5 years, 17/29 (59%) subjects had at least one sign of renal injury; microalbuminuria (n=9), hyperfiltration (n=9), decreased GFR (n=4), and hypertension (n=6). A pediatric nephrologist was involved in care of only 6/17 (35%) with chronic renal injury. Patients have high risks of ongoing residual renal injury and death after ARF; therefore, periodic evaluation after the initial insult is necessary.


Subject(s)
Acute Kidney Injury/mortality , Acute Kidney Injury/pathology , Acute Kidney Injury/psychology , Adolescent , Adult , Child , Child, Preschool , Creatinine/urine , Female , Follow-Up Studies , Glomerular Filtration Rate , Humans , Hypertension/etiology , Infant , Kidney/pathology , Longitudinal Studies , Male , Quality of Life
15.
Int J Artif Organs ; 29(12): 1105-8, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17219349

ABSTRACT

Currently available extracorporeal circuits in the US often require blood priming to prevent hypotension/anemia in smaller pediatric patients. The PRISMA M10 circuit, available in other countries has not received extensive study and has not been cleared for use in the US. We performed an FDA mandated study of the M10 circuit in the US for use in critically ill pediatric patients with acute kidney injury <15 kg in size. FDA guidelines allowed for maximal blood pump flow of 20 ml/min. Fifteen pts (9 M, 6 F, mean size 5.8+/-2.8 kg, range 2.6-12.5 kg, age 4 d - 13 mo, mean creatinine =1.2+/-0.7 mg/dL) were studied at 4 ppCRRT centers. Sixty-one filters (range 1-4 circuits per pt) were used (mean circuit life 28.6+/-22.5 h, range 1 to 74.5 h, 55%>24 h). No blood leaks occurred. All circuits achieved Qb 20 ml/min. Forty-two out of 61 filters clotted and mean circuit life was lower for these filters than those changed for other reasons (23+/-17 vs. 41+/-28 h, <0.005). Circuits using larger access demonstrated significantly longer survival. We conclude that the M10 filter can serve well for CRRT in small pediatric patients. Further study is needed to determine in higher blood flow rates would decrease clotting rates and increase filter life span and ultrafiltration rates.


Subject(s)
Acrylic Resins , Acrylonitrile/analogs & derivatives , Acute Kidney Injury/therapy , Membranes, Artificial , Renal Dialysis/instrumentation , Acute Kidney Injury/mortality , Female , Humans , Infant , Infant, Newborn , Kidney Function Tests , Male , Prospective Studies , Registries , Survival Rate , Treatment Outcome
16.
Int J Artif Organs ; 27(1): 9-14, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14984178

ABSTRACT

Many issues plague the pediatric ARF outcome literature, which include data only from single center sources, a relative lack of prospective study, mixture within studies of renal replacement therapy modality without stratification and inconsistent use of methods to control for patient illness severity in outcome analysis. Since January 2001, the Prospective Pediatric CRRT (ppCRRT) Registry Group has been collecting data from multiple United States pediatric centers to obtain demographic data regarding pediatric patients who receive CRRT, assess the effect of different CRRT prescriptions on circuit function and evaluate the impact of clinical variables on patient outcome. The aim of the current paper is to describe the ppCRRT Registry design, review the decision process and rationale for the options chosen for the ppCRRT format and discuss the analysis plan and future projects envisioned for the ppCRRT Registry.


Subject(s)
Renal Replacement Therapy/methods , Acute Kidney Injury/complications , Acute Kidney Injury/mortality , Acute Kidney Injury/therapy , Child , Humans , Multiple Organ Failure/etiology , Prospective Studies , Registries , Research Design , Risk Factors , Severity of Illness Index , United States
17.
Nature ; 423(6943): 956-61, 2003 Jun 26.
Article in English | MEDLINE | ID: mdl-12827193

ABSTRACT

A high-resolution mapping and sampling study of the Gakkel ridge was accomplished during an international ice-breaker expedition to the high Arctic and North Pole in summer 2001. For this slowest-spreading endmember of the global mid-ocean-ridge system, predictions were that magmatism should progressively diminish as the spreading rate decreases along the ridge, and that hydrothermal activity should be rare. Instead, it was found that magmatic variations are irregular, and that hydrothermal activity is abundant. A 300-kilometre-long central amagmatic zone, where mantle peridotites are emplaced directly in the ridge axis, lies between abundant, continuous volcanism in the west, and large, widely spaced volcanic centres in the east. These observations demonstrate that the extent of mantle melting is not a simple function of spreading rate: mantle temperatures at depth or mantle chemistry (or both) must vary significantly along-axis. Highly punctuated volcanism in the absence of ridge offsets suggests that first-order ridge segmentation is controlled by mantle processes of melting and melt segregation. The strong focusing of magmatic activity coupled with faulting may account for the unexpectedly high levels of hydrothermal activity observed.

18.
Am Surg ; 67(11): 1059-65; discussion 1065-7, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11730222

ABSTRACT

Achalasia is an esophageal motility disorder characterized by the failure of lower esophageal sphincter relaxation and the absence of esophageal peristalsis. The purpose of this study was to evaluate the clinical outcomes of patients undergoing laparoscopic esophageal myotomy and Toupet fundoplication for achalasia. A 9-cm myotomy was performed in most cases extending 7 cm above and 2 cm below the gastroesophageal junction. Severity of dysphagia, heartburn, chest pain, and regurgitation was graded preoperatively and postoperatively using a five-point symptomatic scale (0-4). Patients also graded their outcomes as excellent, good, fair, or poor. Between December 1995 and November 2000 a total of 49 patients (23 male, 26 female) with a mean age of 44.3 years (range 23-71 years) were diagnosed with achalasia. Mean duration of symptoms was 40.2 months (range 4-240 months). Thirty-seven patients (76%) had had a previous nonsurgical intervention or combinations of nonsurgical interventions [pneumatic dilation (23), bougie dilation (five), and botulinum toxin (19)], and two patients had failed esophageal myotomies. Forty-five patients underwent laparoscopic esophageal myotomy and Toupet fundoplication. Two patients received laparoscopic esophageal myotomies without an antireflux procedure, and two were converted to open surgery. One patient presented 10 hours after a pneumatically induced perforation and underwent a successful laparoscopic esophageal myotomy and partial fundoplication. Mean operative time was 180.5 minutes (range 145-264 minutes). Mean length of stay was 1.98 days (range 1-18 days). There were five (10%) perioperative complications but no esophageal leaks. There was a significant difference (P < 0.05) between the preoperative and postoperative dysphagia, chest pain, and regurgitation symptom scores. All patients stated that they were improved postoperatively. Eighty-six per cent rated their outcome as excellent, 10 per cent as good, and 4 per cent as fair. Laparoscopic anterior esophageal myotomy and Toupet fundoplication effectively alleviates dysphagia, regurgitation, and chest pain accompanying achalasia and is associated with high patient satisfaction, a rapid hospital discharge, and few complications.


Subject(s)
Esophageal Achalasia/surgery , Esophagus/surgery , Fundoplication/methods , Laparoscopy , Adult , Aged , Deglutition Disorders/etiology , Esophageal Achalasia/complications , Female , Humans , Length of Stay , Male , Middle Aged , Minimally Invasive Surgical Procedures , Retrospective Studies
19.
Adv Ren Replace Ther ; 8(3): 173-9, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11533918

ABSTRACT

The prevalence of pediatric patients receiving hemodialysis as renal replacement therapy has increased over the past decade. Although numerous technologic advances have been developed and their impact assessed for adult patients receiving hemodialysis, no long-term outcome study currently exists for children receiving hemodialysis. Barriers to such study include the necessity for long-term multicenter participation to enroll enough patients to make definitive statements regarding outcome, lack of consensus for an acceptable and practical method for hemodialysis adequacy measurement in children, and the need for pediatric end-stage renal disease (ESRD)-specific tools for assessment of quality of life. The first part of this article reviews issues surrounding hemodialysis adequacy measurement in children. In particular, simple but accurate Kt/V and normalized protein catabolic rate (nPCR) estimation methods are proposed that should allow for more widespread use of Kt/V and nPCR for measurement of urea clearance and nutritional status in children receiving hemodialysis, important for both patient care and to control for hemodialysis adequacy in pediatric outcome studies. In addition, the principles and pediatric study of 2 technologic advances, continuous noninvasive monitoring of hematocrit and noninvasive ultrasound dilution vascular access flow measurement, are reviewed. Finally, suggestions are provided for future study pertinent to both short-term and long-term outcomes in children receiving hemodialysis.


Subject(s)
Kidney Failure, Chronic/therapy , Renal Dialysis/trends , Child , Humans
20.
Am J Kidney Dis ; 38(3): 553-9, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11532688

ABSTRACT

Semipermanent venous catheters remain the most commonly used access for chronic hemodialysis (HD) in pediatric patients. The recent availability of Tesio catheters in 7 and 10 F has expanded available HD catheter options for children and adolescents. We report our experience with Tesio catheter survival, complications, and effect on dialysis adequacy in comparison to standard dual-lumen (DL) catheters in our pediatric HD patients. Demographic data were similar between the two groups. Overall actuarial survival was significantly longer for Tesio versus DL catheters (46% versus 0% at 1 year; P = 0.003). A comparison of smaller catheters (7 F Tesio catheter, 8 or 10 F DL catheter) showed that smaller Tesio catheters had a significantly longer survival (median survival, 244 versus 13 catheter-days; P < 0.01). Tesio 10 F catheters also survived significantly longer than the larger 11.5 and 12 F DL catheters (P < 0.02). Catheter sepsis occurred less frequently with Tesio catheters (one episode/20 catheter-months) than DL catheters (one episode/5 catheter-months) despite the longer duration of Tesio catheters. Adequate dialysis (single-pool Kt/V > 1.2) was delivered with the same frequency, but for a longer duration with Tesio catheters (76% +/- 32% over 100 monthly measurements versus DL catheter, 57% +/- 45% over 54 monthly measurements). Our clinical practice was to replace cuffed catheters when adequate dialysis could not be delivered. We conclude that Tesio catheters provide superior performance compared with DL catheters in terms of catheter survival, infection rates, and duration of adequate performance.


Subject(s)
Catheters, Indwelling , Kidney Failure, Chronic/therapy , Renal Dialysis/instrumentation , Adolescent , Adult , Catheterization, Peripheral/adverse effects , Catheterization, Peripheral/methods , Catheters, Indwelling/adverse effects , Child , Equipment Failure , Female , Humans , Infections/etiology , Male , Time Factors
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