Clinical Focus

  • Pediatric Critical Care Medicine

Academic Appointments

Professional Education

  • Medical Education: Western University of Health Sciences College of Osteopathic Medicine of the Pacific (2000) CA
  • Board Certification: American Board of Pediatrics, Pediatric Critical Care Medicine (2010)
  • Fellowship: AI Dupont Hospital for Children (2010) DE
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2005)
  • Fellowship: Cedars-Sinai Nephrology Fellowship Program (2005) CA
  • Board Certification: American Board of Pediatrics, Pediatrics (2004)
  • Residency: LACplusUSC Pediatric Residency (2004) CA

All Publications

  • Creation of a Pediatric Sedation Risk Assessment Scoring System: A Novel Method to Stratify Risk JOURNAL OF PEDIATRIC INTENSIVE CARE Couloures, K. G., Anderson, M. P., Hill, C. L., Chen, A., Buckmaster, M. A. 2022
  • Dexmedetomidine for Sedation During Pediatric Noninvasive Ventilation RESPIRATORY CARE Eidman, D. B., Clauss, C. L., Kelly, S. A., Rhieu, J. M., McCollum, S., Couloures, K. G. 2022; 67 (3): 301-307


    Noninvasive ventilation (NIV) facilitates management of acute respiratory failure without intubation. Many pediatric patients cannot tolerate the discomfort associated with noninvasive support and require sedation with agents that may decrease respiratory drive. Dexmedetomidine does not decrease respiratory drive, and we hypothesized that its use would increase tolerance of noninvasive respiratory support without increasing risk for intubation.A retrospective chart review was performed of all subjects at least 3 months of age with acute respiratory failure requiring NIV who were admitted to the pediatric ICU at a children's hospital for a 3-y period from 2015-2018. Subjects were stratified to those receiving continuous dexmedetomidine versus those not receiving sedation. Medical history was reviewed for developmental delay (DD) or intellectual disability (ID) as well as basic demographic information. To control the association between these variables with both dexmedetomidine use and intubation, augmented inverse probability weighting was utilized to establish equivalent baselines between the dexmedetomidine and no-sedation groups. Primary outcome was intubation rate within 6 h of initiation of dexmedetomidine infusion or NIV.Based on the strong association between age and dexmedetomidine use, a statistical model including subjects > age 5 was not able to be generated, and these subjects were excluded from final analysis. One-hundred eight subjects were included in the final statistical analysis, with 60 receiving dexmedetomidine and 48 receiving no sedation. Dexmedetomidine was effective at reducing agitation, with no difference noted in intubation rate at 6 h between subjects receiving dexmedetomidine versus no sedation (13.1 vs 12.4%).Dexmedetomidine may allow tolerance of NIV in acute respiratory failure without increasing risk for intubation, especially in preschool age patients and those with DD or ID. A larger study involving multiple centers would help support our conclusions.

    View details for DOI 10.4187/respcare.09360

    View details for Web of Science ID 000761097500004

    View details for PubMedID 35078930

  • Efficacy of Intravenous Ketamine in Adolescent Treatment-Resistant Depression: A Randomized Midazolam-Controlled Trial. The American journal of psychiatry Dwyer, J. B., Landeros-Weisenberger, A., Johnson, J. A., Londono Tobon, A., Flores, J. M., Nasir, M., Couloures, K., Sanacora, G., Bloch, M. H. 2021: appiajp202020010018


    OBJECTIVE: Adolescent depression is prevalent and is associated with significant morbidity and mortality. Although intravenous ketamine has shown efficacy in adult treatment-resistant depression, its efficacy in pediatric populations is unknown. The authors conducted an active-placebo-controlled study of ketamine's safety and efficacy in adolescents.METHODS: In this proof-of-concept randomized, double-blind, single-dose crossover clinical trial, 17 adolescents (ages 13-17) with a diagnosis of major depressive disorder received a single intravenous infusion of either ketamine (0.5 mg/kg over 40 minutes) or midazolam (0.045 mg/kg over 40 minutes), and the alternate compound 2 weeks later. All participants had previously tried at least one antidepressant medication and met the severity criterion of a score >40 on the Children's Depression Rating Scale-Revised. The primary outcome measure was score on the Montgomery-Asberg Depression Rating Scale (MADRS) 24 hours after treatment.RESULTS: A single ketamine infusion significantly reduced depressive symptoms 24 hours after infusion compared with midazolam (MADRS score: midazolam, mean=24.13, SD=12.08, 95% CI=18.21, 30.04; ketamine, mean=15.44, SD=10.07, 95% CI=10.51, 20.37; mean difference=-8.69, SD=15.08, 95% CI=-16.72, -0.65, df=15; effect size=0.78). In secondary analyses, the treatment gains associated with ketamine appeared to remain 14 days after treatment, the latest time point assessed, as measured by the MADRS (but not as measured by the Children's Depression Rating Scale-Revised). A significantly greater proportion of participants experienced a response to ketamine during the first 3 days following infusion as compared with midazolam (76% and 35%, respectively). Ketamine was associated with transient, self-limited dissociative symptoms that affected participant blinding, but there were no serious adverse events.CONCLUSIONS: In this first randomized placebo-controlled clinical trial of intravenous ketamine in adolescents with depression, the findings suggest that it is well tolerated acutely and has significant short-term (2-week) efficacy in reducing depressive symptoms compared with an active placebo.

    View details for DOI 10.1176/appi.ajp.2020.20010018

    View details for PubMedID 33653121

  • How Residents Learn During Emergent Situations May Be Different Than How We Were Taught. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies Couloures, K. G. 2020; 21 (10): 901–2

    View details for DOI 10.1097/PCC.0000000000002466

    View details for PubMedID 33009300

  • Pediatric Delirium: a Review of Current Diagnosis and Management in the Intensive Care Setting CURRENT PEDIATRICS REPORTS Gu, S., Couloures, K. 2020; 8 (3): 80-85
  • Can We Use Tissue Inhibitor Metalloproteinase-2 and Insulin-Like Growth Factor Binding Protein-7 Levels to Predict Acute Kidney Injury in Neonate and Infants Undergoing Cardiac Surgery? Not Yet. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies Couloures, K. G., Marsenic, O. 2020; 21 (6): 593–94

    View details for DOI 10.1097/PCC.0000000000002282

    View details for PubMedID 32483026

  • Barriers to Communication in a PICU: A Qualitative Investigation of Family and Provider Perceptions* PEDIATRIC CRITICAL CARE MEDICINE Greenway, T. L., Rosenthal, M. S., Murtha, T. D., Kandil, S. B., Talento, D. L., Couloures, K. G. 2019; 20 (9): e415-e422


    Family and medical provider perceptions of communication barriers within the PICU are poorly understood. We designed a qualitative study to characterize the perspective of families and medical providers of critically ill children regarding communication barriers. The identified barriers may be used to direct efforts to improve communication.Semi-structured interviews were conducted from August 2017 to January 2018. Interviews were audio recorded and professionally transcribed verbatim.A PICU at a tertiary care academic center.Forty-two families whose children were admitted to the PICU (excluding patients receiving end-of-life care or with protective services involvement) and 12 PICU staff members, including nurses, residents, fellows, and attending's.None.An interprofessional team of a physician, nurse manager, and medical student coded the transcripts. Interviewing continued until thematic saturation was reached. Codes were organized into common themes using a modified constant comparative method. The families interviewed represented 16 previously healthy children, and 26 children with a chronic health condition. Staff interviewed included three residents, three fellows, three attending intensivists, and three nurses. Participants' perceptions and experiences of barriers to communication included the following: 1) Communication breakdowns related to coordination of care among several services, 2) Family-centered rounds are insufficient for effective communication, 3) Undervaluing the knowledge of families of children with chronic health conditions or special needs, and 4) Communication breakdowns occur across provider hand-offs. Theme 3 was identified by families, but not by providers.Families and medical providers both identified several barriers to communication. However, only families identified the barrier "Undervaluing the knowledge of families with chronically ill children." Future work should explore these barriers and the discrepancy in perception between providers and families to determine if there are interventions that improve both family satisfaction and patient care.

    View details for DOI 10.1097/PCC.0000000000002070

    View details for Web of Science ID 000485040200003

    View details for PubMedID 31261228

  • Evaluating the Need for Pediatric Procedural Sedation Training in Pediatric Critical Care Medicine Fellowship* PEDIATRIC CRITICAL CARE MEDICINE Hooper, M. C., Kamat, P. P., Couloures, K. G. 2019; 20 (3): 259-261


    Pediatric procedural sedation has been increasingly performed by pediatric intensivists over the past decade. Pediatric Critical Care Medicine fellowship guidelines do not specify how fellows obtain proficiency in pediatric procedural sedation. We sought to survey the state of pediatric procedural sedation training during fellowship and whether fellows thought it was sufficient.A 21-question survey gathered data on pediatric procedural sedation training provided to Pediatric Critical Care Medicine fellows. Surveys were sent to fellowship directors with instructions to distribute to second- and third-year fellows or recent graduates. Over 2 months, up to three e-mail reminders were sent to fellowship directors whose program had not completed at least one survey.Senior fellows and graduates of 65 active Accreditation Council for Graduate Medical Education Pediatric Critical Care Medicine fellowship programs.None.Sixty-five percent of fellowship programs (42/65) returned at least one response. Ninety senior fellows and 27 recent graduates responded. Of respondents, 38% received pediatric procedural sedation training during the fellowship, and 32% reported mandatory training. Nine percent of programs used simulation. Although 61% who received training felt adequately prepared to perform pediatric procedural sedation, 25% needed additional preceptorship to sedate independently. Nearly one third (31%) reported that completion of a predetermined number of cases was required to sedate independently. Forty-eight percent reported a minimum number of cases was required for hospital credentialing. Nearly 45% were allowed to perform pediatric procedural sedation off the unit after receiving credentials. When asked if inadequate pediatric procedural sedation training would be a deterrent to applying for a position that included pediatric procedural sedation, 8.6% replied yes, 52.6% replied no, and 38.8% replied they were unsure.Pediatric procedural sedation lacks a clearly defined training pathway. Most fellows find pediatric procedural sedation a valuable skill set. We propose that all Pediatric Critical Care Medicine fellows receive training that includes pediatric procedural sedation critical incident simulation and cases performed outside the PICU to establish proficiency.

    View details for DOI 10.1097/PCC.0000000000001809

    View details for Web of Science ID 000460169200014

    View details for PubMedID 30431555

  • Sedation and Analgesia Using Medications Delivered via the Extravascular Route in Children Undergoing Laceration Repair. The journal of pediatric pharmacology and therapeutics : JPPT : the official journal of PPAG Miller, J. L., Capino, A. C., Thomas, A., Couloures, K., Johnson, P. N. 2018; 23 (2): 72-83


    OBJECTIVES: To describe the method of delivery, dosage regimens, and outcomes of sedatives and analgesics administered via the extravascular route for laceration repair in children.METHODS: Medline, Embase, and International Pharmaceutical Abstracts were searched using the keywords "child," "midazolam," "ketamine," dexmedetomidine," "fentanyl," "nitrous oxide" (N2O), and "laceration repair." Articles evaluating the use of extravascular sedation in children for laceration repair published in the English language between 1946 and June 2017 were included. Two authors independently screened each article for inclusion. Reports were excluded if they did not contain sufficient details on dosage regimen and outcomes.RESULTS: A total of 16 reports representing 953 children receiving sedatives and analgesics via the extravascular route were included for analyses. A statistical analysis was not performed because of heterogeneity in dosing and types of analyses conducted. Midazolam and N2O were the most common agents, with oral (PO) midazolam being the most common agent. Other agents that have supporting data were intranasal (IN) dexmedetomidine, IN ketamine, IN midazolam, PO diazepam, PO ketamine, transmucosal (TM) midazolam, and TM fentanyl.CONCLUSIONS: Most of the agents administered through the extravascular route were efficacious. Selection of the agents should be based on perceived need for analgesia versus sedation, patient accessibility, and adverse drug events. Future research is needed to determine the optimal agent and route for laceration repair.

    View details for DOI 10.5863/1551-6776-23.2.72

    View details for PubMedID 29720907

  • Outcomes following implementation of a pediatric procedural sedation guide for referral to general anesthesia for magnetic resonance imaging studies PEDIATRIC ANESTHESIA Grunwell, J. R., Marupudi, N. K., Gupta, R. V., Travers, C. D., McCracken, C. E., Williamson, J. L., Stockwell, J. A., Fortenberry, J. D., Couloures, K., Cravero, J., Kamat, P. P. 2016; 26 (6): 628-636


    Guidelines for referral of children to general anesthesia (GA) to complete MRI studies are lacking. We devised a pediatric procedural sedation guide to determine whether a pediatric procedural sedation guide would decrease serious adverse events and decrease failed sedations requiring rescheduling with GA.We constructed a consensus-based sedation guide by combining a retrospective review of reasons for referral of children to GA (n = 221) with published risk factors associated with the inability to complete the MRI study with sedation. An interrupted time series analysis of 11 530 local sedation records from the Pediatric Sedation Research Consortium between July 2008 and March 2013, adjusted for case-mix differences in the pre- and postsedation guide cohorts, evaluated whether a sedation guide resulted in decreased severe adverse events (SAE) and failed sedation rates.A significant increase in referrals to GA following implementation of a sedation guide occurred (P < 0.001), and fewer children with an ASA-PS class ≥III were sedated using procedural sedation (P < 0.001). There was no decrease in SAE (P = 0.874) or in SAE plus airway obstruction with concurrent hypoxia (P = 0.435). There was no change in the percentage of failed sedations (P = 0.169).More studies are needed to determine the impact of a sedation guide on pediatric procedural sedation services.

    View details for DOI 10.1111/pan.12903

    View details for Web of Science ID 000375551900008

    View details for PubMedID 27061749

    View details for PubMedCentralID PMC5024537

  • Effect of the decrease in dialysate sodium in pediatric patients on chronic hemodialysis HEMODIALYSIS INTERNATIONAL Marsenic, O., Anderson, M., Couloures, K. G., Hong, W. S., Kevin Hall, E., Dahl, N. 2016; 20 (2): 277-285


    Optimal dialysate sodium (dNa) is unknown, with both higher and lower values suggested in adult studies to improve outcomes. Similar studies in pediatric hemodialysis (HD) population are missing. This is the first report of the effect of two constant dNa concentrations in pediatric patients on chronic HD. 480 standard HD sessions and interdialytic periods were studied in 5 patients (age 4-17 years, weight 20.8-66 kg) during a period of 6-11 months per patient. dNa was 140 mEq/L during the first half, and 138 mEq/L during the second half of the study period for each patient. Lowering dNa was associated with improved preHD hypertension, decreased interdialytic weight gain, decreased need for ultrafiltration, lower sodium gradient and was well tolerated despite lack of concordance with predialysis sNa, that was variable. Further studies are needed to verify our findings and to investigate if an even lower dNa may be more beneficial in the pediatric HD population.

    View details for DOI 10.1111/hdi.12384

    View details for Web of Science ID 000373925000018

    View details for PubMedID 26663617

  • Relationship between Interdialytic Weight Gain and Blood Pressure in Pediatric Patients on Chronic Hemodialysis BIOMED RESEARCH INTERNATIONAL Marsenic, O., Anderson, M., Couloures, K. G. 2016; 2016: 5972930


    Overhydration is reported to be the main cause of hypertension (HTN) as well as to have no association with HTN in hemodialysis (HD) population. This is the first report of the relationship between interdialytic weight gain (IDWG) and pre-HD blood pressure (BP) in pediatric patients in relation to residual urine output (RUO). We studied 170 HD sessions and interdialytic periods performed during a 12-week period in 5 patients [age 4-17 years, weight 20.8-66 kg, 3 anuric (102 HD sessions), and 2 nonanuric (68 HD sessions)]. BP is presented as systolic BP index (SBPI) and diastolic BP index (DBPI), calculated as systolic or diastolic BP/95th percentile for age, height, and gender. IDWG did not differ (P > 0.05) between anuric and nonanuric pts. There was a positive but not significant correlation between IDWG and both pre-HD SBPI (r = 0.833, P = 0.080) and pre-HD DBPI (r = 0.841, P = 0.074). Pre-HD SBPI (1.01 ± 0.12 versus 1.13 ± 0.18) and DBPI (0.92 ± 0.16 versus 1.01 ± 0.24) were higher in nonanuric patents (P < 0.001 and P < 0.01, resp.). Pre-HD HTN may not be solely related to IDWG and therapies beyond fluid removal may be needed. Individualized approach to HTN management is necessary in pediatric dialysis population.

    View details for DOI 10.1155/2016/5972930

    View details for Web of Science ID 000387392100001

    View details for PubMedID 27843947

    View details for PubMedCentralID PMC5098057

  • Non-Intravenous Sedatives and Analgesics for Procedural Sedation for Imaging Procedures in Pediatric Patients. The journal of pediatric pharmacology and therapeutics : JPPT : the official journal of PPAG Thomas, A., Miller, J. L., Couloures, K., Johnson, P. N. 2015; 20 (6): 418-30


    OBJECTIVES: The purpose of this study was to describe the method of delivery, dosage regimens, and outcomes of sedatives administered by extravascular route for imaging procedures in children.METHODS: Medline, Embase, International Pharmaceutical Abstracts, and Cochrane Database of Systematic Reviews were searched using keywords "child", "midazolam", "ketamine", dexmedetomidine", "fentanyl", "nitrous oxide", and "imaging." Articles evaluating the use of extravascular sedation in children for imaging procedures published in English between 1946 and March 2015 were included. Two authors independently screened each article for inclusion. Reports were excluded if they did not contain sufficient details on dosage regimens and outcomes.RESULTS: Twenty reports representing 1,412 patients ranging in age from 0.33 to 19 years of age were included for analysis. Due to discrepancies in doses and types of analyses, statistical analyses were not performed. Oral midazolam was the most common agent evaluated; other agents included intranasal (IN) ketamine, IN midazolam, IN fentanyl, IN and transmucosal dexmedetomidine, and N2O. Most agents were considered efficacious compared with placebo.CONCLUSIONS: Most agents showed efficacy for sedation during imaging when delivered through an extra-vascular route. Selection of agents should be based on onset time, duration, patient acceptability, recovery time, and adverse events. More robust studies are necessary to determine the optimal agent and route to utilize for imaging procedures when sedation is needed.

    View details for DOI 10.5863/1551-6776-20.6.418

    View details for PubMedID 26766932

  • Prevalence and Predictors of Adverse Events during Procedural Sedation Anesthesia-Outside the Operating Room for Esophagogastroduodenoscopy and Colonoscopy in Children: Age Is an Independent Predictor of Outcomes PEDIATRIC CRITICAL CARE MEDICINE Biber, J. L., Allareddy, V., Allareddy, V., Gallagher, S. M., Couloures, K. G., Speicher, D. G., Cravero, J. P., Stormorken, A. G. 2015; 16 (8): E251-E259


    Procedural sedation/anesthesia outside the operating room for a variety of procedures is well described with an overall low adverse event rate in certain settings. Adverse event associated with procedural sedation/anesthesia outside the operating room for gastrointestinal procedures have been described, albeit in small, single-center studies with wide variance in outcomes. Predictors of such outcomes are unclear. We aimed to estimate the prevalence of adverse event in children undergoing procedural sedation/anesthesia outside the operating room for esophagogastroduodenoscopy, colonoscopy, or both to identify predictors of adverse event.Retrospective analysis of Pediatric Sedation Research Consortium database, a large data repository of pediatric patients aged 21 years old or younger undergoing procedural sedation/anesthesia outside the operating room during September 2007 to November 2011. Twenty-two of the 40 centers provided data pertaining to the procedure of interest.None.Primary outcome variable is any adverse event. Independent variables include: age (five groups), sex, American Societyof Anaesthesiologists status, procedure (esophagogastroduodenoscopy, colonoscopy, or both), provider responsible, medication used, location, and presence of coexisting medical conditions. Descriptive statistics used to summarize the data. Using multivariablelogistic regression model, odds ratio, 95% CI) were computed. A total of 12,030 procedures were performed (esophagogastroduodenoscopy, 7,970; colonoscopy, 1,378; and both, 2,682). A total of 96.9% of patients received propofol. Eighty-three percent were performed in a sedation unit. Prevalence of adverse event was 4.8%. The most common adverse event were persistent desaturations (1.5%), airway obstruction (1%), cough (0.9%), and laryngospasm (0.6%). No deaths or CPR occurred. Infants and children aged 5 years old or younger had a higher adverse event rate than older children (15.8%, 7.8% vs 4%). Regression analysis revealed age 5 years old or younger, American Society of Anaesthesiologists greater than or equal to 2, esophagogastroduodenoscopy ± colonoscopy, and coexisting medical conditions of obesity and lower airway disease were independent predictors of higher adverse event.Overall prevalence of any adverse event was 4.8%. Independent predictors of adverse events in procedural sedation/anesthesia outside the operating room in pediatric esophagogastroduodenoscopy/colonoscopy onoscopy were identified. Recognition of such risk factors may enable optimization of procedural sedation.

    View details for DOI 10.1097/PCC.0000000000000504

    View details for Web of Science ID 000369708000001

    View details for PubMedID 26218257

  • Comparison of cystatin C and Beta-2-microglobulin kinetics in children on maintenance hemodialysis HEMODIALYSIS INTERNATIONAL Marsenic, O., Wierenga, A., Wilson, D. R., Anderson, M., Shrivastava, T., Simon, G. A., Beck, A. M., Swanson, T. J., Studnicka, K., Elberg, D., Singh, N. S., Couloures, K., Henry, D., Turman, M. A. 2013; 17: S11-S16


    Middle-molecules (MM) are not monitored in children on hemodialysis (HD), but are accumulated and increase the risk of cardiovascular disease and mortality. Molecular properties of Cystatin C (CyC), 13 kDa, potentially make it a preferred MM marker over Beta-2-Microglobulin (B2M), 12 kDa. We compared CyC and B2M kinetics to investigate if CyC can be used as preferred MM marker. CyC (mg/L) and B2M (μg/mL) were measured in 21 low-flux HD sessions in seven children. Blood samples were taken at HD start (pre), 1 and 2 hours into HD and at end of HD (post) for all sessions and 60 minutes after the first HD (Eq). PreCyC (9.85 ± 2.15) did not differ (P > 0.05) from postCyC (10.04 ± 2.83). PostB2M (38.87 ± 7.12) was higher (P < 0.05) than preHD B2M (33.27 ± 7.41). There was no change in CyC at 1 and 2 hours into HD, while B2M progressively increased. CyC or B2M changes did not significantly correlate with spKt/V (2.09 ± 0.86), ultrafiltration (4.61 ± 1.98%) or HD duration (218 ± 20 minutes). EqCyC was not different from postCyC (11.07 ± 3.14 vs. 10.71 ± 2.85, P > 0.05), while EqB2M was lower than postB2M (36.48 ± 7.68 vs. 41.09 ± 8.99, P < 0.05). MMs as represented by B2M and CyC are elevated in children on standard HD. Intensified HD modalities would be needed for their removal. B2M is affected by the dialytic process with a rise during HD independent of ultrafiltration and decrease 1 hour after, while CyC remains unchanged. We suggest that CyC be used as preferred marker of MM removal and as a marker of adequacy of intensified HD regimens.

    View details for DOI 10.1111/hdi.12083

    View details for Web of Science ID 000329302700001

    View details for PubMedID 24134324

  • Hyperkalemia and Ventricular Tachycardia After Outpatient Ureteral Valve Reimplantation A Case Report PEDIATRIC EMERGENCY CARE Wyrick, S., Couloures, K. G., Dupuis, G. M., Williams, R. S. 2013; 29 (5): 650-652


    This study aimed to report on a toddler who presented with progressively worsening abdominal pain and obstructive uropathy 1 week after ureteral valve reimplantation. Acute renal failure resulted in critical hyperkalemia.Chart review of presentation, physical examination, laboratory tests, and treatment.Initial potassium level was 10 mEq/L; ventricular tachycardia was observed and treated.More commonly, hyperkalemia results from overuse/overdose of supplementation or in patients with known renal failure. Although less common, obstructive uropathy should be considered in any patient with recent instrumentation of the urinary tract and coincident complications can be significant.

    View details for DOI 10.1097/PEC.0b013e31828ec00a

    View details for Web of Science ID 000318549400020

    View details for PubMedID 23640146

  • Cystatin C in children on chronic hemodialysis PEDIATRIC NEPHROLOGY Marsenic, O., Wierenga, A., Wilson, D. R., Anderson, M., Shrivastava, T., Simon, G. A., Beck, A. M., Swanson, T. J., Studnicka, K., Elberg, D., Couloures, K., Turman, M. A. 2013; 28 (4): 647-653


    Cystatin C (CyC) concentration has been suggested as a marker of middle-molecule accumulation, hemodialysis (HD) adequacy and for estimating residual renal function (RRF), but it has not been studied in pediatric HD. High CyC is associated with increased cardiovascular disease (CVD). We investigated CyC kinetics and the effect of RRF on CyC in a pediatric HD population.A total of 21 HD sessions and 20 interdialytic periods were analyzed in seven patients, age 5-19 years, of whom four were anuric (A) and three were non-anuric (NA). CyC was measured before (preHD) and after (postHD) three standard HD sessions in 1 week and prior to the first session of the following week.We found no difference (p=0.67) in CyC concentration between preHD CyC (9.85 ± 2.15 mg/l; A vs. NA, p=0.37) and postHD CyC (10.04 ± 2.83 mg/l; A vs NA, p=0.28). The weekly average preHD CyC median concentration was 10.14 mg/l (A vs. NA, p=0.87) and correlated with age (r=0.808, p=0.03) and height measurement (r=0.799, p=0.03), but not with RRF, single-pool Kt/V, ultrafiltration, HD duration or blood liters processed.Cystatin C is very elevated in children on HD. It does not rise between HD sessions, is not removed by standard HD and remains at steady state; therefore, elimination is extrarenal. Low RRF does not affect CyC elimination. CyC increases with age and height. If a high CyC concentration can be proven to have a causative role in the development of CVD, routine intensified HD regimens in children may be indicated for its removal.

    View details for DOI 10.1007/s00467-012-2366-7

    View details for Web of Science ID 000316063000017

    View details for PubMedID 23179198

  • Analysis of procedural sedation provided by pediatricians PEDIATRICS INTERNATIONAL Monroe, K. K., Beach, M., Reindel, R., Badwan, L., Couloures, K. G., Hertzog, J. H., Cravero, J. P. 2013; 55 (1): 17-23


    Pediatric procedural sedation outside of the operating room is performed by a variety of pediatric specialists. Using the database from the Pediatric Sedation Research Consortium (PSRC), patient demographics, medications used, diagnoses, complications, and procedures involved when pediatricians provided sedation in this cohort, were described. 'Pediatrician' was defined as a general pediatrician, cardiologist, endocrinologist, gastroenterologist, hematologist/oncologist, neurologist, pulmonologist or hospitalist.Data were collected by the PSRC, a group of 35 institutions dedicated to improving sedation care for children. Members prospectively enrolled consecutive patients who received sedation or anesthesia for diagnostic or therapeutic procedures. Data on demographics, primary diagnoses, procedures, medications, interventions, and complications were collected and stored on a Web-based data collection tool.A total of 12 113 sedations performed by pediatricians were submitted from 1 July 2004 to 31 December 2008, compared to 119 665 cases performed by non-pediatricians. Pediatrician patients were more frequently non-emergency American Society of Anesthesiologists (ASA) class I or II, aged 2-8 years old, with a neurologic primary diagnosis, being sedated for a radiologic procedure with a sedative. Distraction techniques were used more frequently in the pediatrician group (11.9% vs 3.1%). The most common complication encountered was inadequate sedation, which occurred 2.2% of the time.Pediatricians sedate for a variety of patients within the PSRC, but the patients tended to be younger, predominately ASA class I or II, non-emergency, and undergoing non-painful procedures when compared to non-pediatrician providers. The patient demographics, medications used, diagnoses, complications, and procedures involved varied between the groups significantly. Complication rates were similar between the groups.

    View details for DOI 10.1111/j.1442-200X.2012.03743.x

    View details for Web of Science ID 000315094100005

    View details for PubMedID 23062205

  • Infant with gross hematuria and nephrotic syndrome: answers PEDIATRIC NEPHROLOGY Marsenic, O., Wasti, A., Yu, Z., Couloures, K., Henry, D., Turman, M. 2012; 27 (4): 565-569
  • Impact of Provider Specialty on Pediatric Procedural Sedation Complication Rates PEDIATRICS Couloures, K. G., Beach, M., Cravero, J. P., Monroe, K. K., Hertzog, J. H. 2011; 127 (5): E1154-E1160


    To determine if pediatric procedural sedation-provider medical specialty affects major complication rates when sedation-providers are part of an organized sedation service.The 38 self-selected members of the Pediatric Sedation Research Consortium prospectively collected data under institutional review board approval. Demographic data, primary and coexisting illness, procedure, medications used, outcomes, airway interventions, provider specialty, and adverse events were reported on a self-audited, Web-based data collection tool. Major complications were defined as aspiration, death, cardiac arrest, unplanned hospital admission or level-of-care increase, or emergency anesthesia consultation. Event rates per 10 000 sedations, 95% confidence intervals, and odds ratios were calculated using anesthesiologists as the reference group and were then adjusted for age, emergency status, American Society of Anesthesiologists physical status > 2, nil per os for solids, propofol use, and clustering by site.Between July 1, 2004, and December 31, 2008, 131 751 pediatric procedural sedation cases were recorded; there were 122 major complications and no deaths. Major complication rates and 95% confidence intervals per 10 000 sedations were as follows: anesthesiologists, 7.6 (4.6-12.8); emergency medicine, 7.8 (5.5-11.2); intensivist, 9.6 (7.3-12.6); pediatrician, 12.4 (6.9-20.4); and other, 10.2 (5.1-18.3). There was no statistical difference (P > .05) among provider's complication rates before or after adjustment for potential confounding variables.In our sedation services consortium, pediatric procedural sedation performed outside the operating room is unlikely to yield serious adverse outcomes. Within this framework, no differences were evident in either the adjusted or unadjusted rates of major complications among different pediatric specialists.

    View details for DOI 10.1542/peds.2010-2960

    View details for Web of Science ID 000290097800007

    View details for PubMedID 21518718

  • Prenatal lead poisoning due to maternal exposure results in developmental delay PEDIATRICS INTERNATIONAL Couloures, K., Vasan, R. 2011; 53 (2): 242-244
  • Proteinuria in children with sickle cell disease NEPHROLOGY DIALYSIS TRANSPLANTATION Marsenic, O., Couloures, K. G., Wiley, J. M. 2008; 23 (2): 715-720


    Sickle cell nephropathy is characterized by proteinuria that starts in childhood and may lead to renal failure. Microalbuminuria is used as a marker of glomerular damage. There are no data on the extent and type of proteinuria other than microalbuminuria in children with sickle cell disease (SCD). Our goal was characterization of glomerular permselectivity and tubular proteinuria in children with SCD. The improved characterization will allow earlier recognition and prevention of renal damage.Thirty-two stable patients with haemoglobin SS (HbSS) (15 boys and 17 girls, age 9.57 +/- 5.45 years, 8 months to 19 years) were investigated. All patients had normal renal function and tested negative for proteinuria with a dipstick method. Markers of glomerular permselectivity used were albumin (marker of charge selectivity and less severe pore-size selectivity) and immunoglobulin G (IgG, marker of more severe pore-size selectivity). The marker of tubular injury used was retinol-binding protein (RBP, marker of proximal tubular dysfunction). These proteins were measured in urine spot samples using nephelometry. We did not include a control group as values in healthy subjects were previously published.Total protein excretion was elevated in 41% (13/32) of all patients and, of these 13 patients, 38.5% (5/13) had increased microalbuminuria, 15% (2/13) had increased excretion of RBP and 23% (3/13) had increased excretion of IgG. Increased total proteinuria that was not detected by testing for microalbuminuria was found in 61.5% (8/13) of patients. The youngest patient was 3 years old. Increased microalbuminuria was present in 25% (8/32) of all patients and was detected as early as 4 years of age. Of these, 62% (5/8) also had increased total protein excretion and 62% (5/8) also had increased IgG excretion. A total of 62.5% were older than 10 years. RBP excretion was elevated in 16% (5/32) of patients, all of whom were 7-14 years old. None of these patients had increased microalbuminuria or increased excretion of IgG. IgG excretion was elevated in 16% (5/32) of patients and was accompanied by increased microalbuminuria. All patients with increased IgG excretion were > or = 13 years old. We found a weak positive correlation between microalbuminuria and age (0.323, P = 0.07). We did not find a significant correlation between any type of proteinuria and disease morbidity. Ten of the thirty-two patients received hydroxyurea treatment and 60% (6/10) had no proteinuria. Twelve of the thirty-two patients received chronic exchange transfusions and 42% (5/12) had no proteinuria.We found early glomerular selectivity damage in children with SCD, which is secondary to both size-selectivity and charge-selectivity impairment. Microalbuminuria alone does not adequately detect early renal damage in children with SCD. Proximal tubular dysfunction is seen in younger children and is independent of glomerular damage. We suggest that children with SCD be tested for both total protein and IgG excretion in the urine in addition to albumin. Knowing the extent and type of renal damage may allow earlier recognition of renal injury and prompt earlier initiation of preventive therapies.

    View details for DOI 10.1093/ndt/gfm858

    View details for Web of Science ID 000253022300044

    View details for PubMedID 18065783

  • Preventing recurrence of focal segmental glomerulosclerosis following renal transplantation: A case report PEDIATRIC TRANSPLANTATION Couloures, K., Pepkowitz, S. H., Goldfinger, D., Kamil, E. S., Puliyanda, D. P. 2006; 10 (8): 962-965


    While the recurrence of FSGS in a primary renal transplant has been well studied, strategies to prevent subsequent recurrence in later transplants, has not been well formulated. This is important considering that one center's experience with adults reported an initial recurrence rate of 57% with reoccurrence of 37% in subsequent transplants. However, renal function was maintained in 62% (1). In pediatrics, data from a single-center reported 100% recurrence of FSGS in the second allograft after an initial recurrence of 52% (2). Two commentaries reviewing such data, one each in adults and pediatrics, suggested that the benefits of living-related donation might not be realized in patients with FSGS because of this frequent recurrence (3, 4). Here, we report a patient who was considered to be at very high risk for post-transplant recurrence of FSGS, because of the established risk factors, who was successfully retransplanted after a course of pretransplant plasmapheresis, followed by post-transplant plasmapheresis and the use of cyclosporine. Eighteen months post-transplant, he has no proteinuria and his serum creatinine is 1.2 mg/dL.

    View details for DOI 10.1111/j.1399-3046.2006.00571.x

    View details for Web of Science ID 000241678100017

    View details for PubMedID 17096767