1
|
Anand V, Pournami F, Prithvi AK, Nandakumar A, Prabhakar J, Jain N. Every treasured drop! Blood transfusion requirements in very preterm neonates after implementation of blood conservation strategies: an observational analytical study. J Trop Pediatr 2022; 68:6777800. [PMID: 36306125 DOI: 10.1093/tropej/fmac093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Certain morbidities are inevitable in preterm infants; the challenge lies in minimizing them. Anemia of prematurity is multifactorial. Therapy largely depends on adult red blood cell transfusions (RBCT); which inherently, are not without problems. Most literature in this respect are retrospective or evaluate individual stratagems to reduce RBCT. METHODS This observational analytical study was planned to compare need for RBCT, before and after institution of blood conservation strategies (BCS). All those ≤30 weeks gestation at birth during two-time epochs were included (Before BCS: retrospective; After BCS: prospective). BCS constituted of delayed cord clamping (DCC), strict sampling indications, micro-sampling with point-of-care testing (MS-POCT) and adherence to RBCT thresholds. RESULTS Of 45 enrolled neonates in each group, proportion of those requiring even 1 RBCT was significantly reduced after BCS [51.1% vs. 26.7%, p = 0.02, OR 0.35, 95%CI (0.14, 0.84)]. Calculated cumulative blood volume losses (35.3 ml vs. 21.9 ml) and loss per kilogram birth weight (35.3 ml/kg vs. 20.12 ml/kg) were significantly lower after BCS (p = 0.0036). Need for >1 RBCT, mean lowest Hb, mean maximum-hemoglobin drop, need for arterial lines were reduced. Adherence to RBCT thresholds were acceptably good in both time epochs. However, the compliance to DCC was low in both groups, identifying one area of focus with scope for massive improvement. CONCLUSIONS Need for RBCT transfusions largely attributable to reduced blood losses for lab analysis were reduced after BCS. Installation of in-house MS-POCT seemed to be the pivotal factor. Units that care for very preterm infants must make attempts to procure MS-POCT equipment.
Collapse
Affiliation(s)
- Vishnu Anand
- Department of Neonatology, Kerala Institute of Medical Sciences, Trivandrum, India
| | - Femitha Pournami
- Department of Neonatology, Kerala Institute of Medical Sciences, Trivandrum, India
| | - Ajai Kumar Prithvi
- Department of Neonatology, Kerala Institute of Medical Sciences, Trivandrum, India
| | - Anand Nandakumar
- Department of Neonatology, Kerala Institute of Medical Sciences, Trivandrum, India
| | - Jyothi Prabhakar
- Department of Neonatology, Kerala Institute of Medical Sciences, Trivandrum, India
| | - Naveen Jain
- Department of Neonatology, Kerala Institute of Medical Sciences, Trivandrum, India
| |
Collapse
|
2
|
Hellström W, Forssell L, Morsing E, Sävman K, Ley D. Neonatal clinical blood sampling led to major blood loss and was associated with bronchopulmonary dysplasia. Acta Paediatr 2020; 109:679-687. [PMID: 31505053 PMCID: PMC7155086 DOI: 10.1111/apa.15003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 01/23/2023]
Abstract
AIM Studies indicate that reduced foetal haemoglobin levels are related to increased neonatal morbidity rates. This study investigated the relationships between sampling-related blood loss and adult blood transfusions administered during postnatal days 1-14 and the development of severe neonatal morbidities in extremely preterm infants born before 28 weeks of gestation. METHODS The medical files of 149 extremely preterm infants born at two university hospitals in Sweden from 2013 to 2018 were investigated. RESULTS Blood sampling resulted in a 58% depletion of the endogenous blood volume postnatal days 1-14 (median 40.4 mL/kg, interquartile range 23.9-53.3 mL/kg) and correlated with the adult erythrocyte transfusion volume (rS = 0.870, P < .001). Sampling-related blood loss on postnatal days 1-7, adjusted for gestational age at birth and birth weight standard deviation score, was associated with the development of bronchopulmonary dysplasia (BPD) (odds ratio by a 10-unit increase 2.4, 95% confidence interval 1.1-5.4) (P = .03). No associations were found between blood sampling and intraventricular haemorrhage or necrotising enterocolitis in the full statistical model. The largest proportion of sampling-related blood was used for blood gas analyses (48.7%). CONCLUSION Diagnostic blood sampling led to major endogenous blood loss replaced with adult blood components and was associated with the development of BPD.
Collapse
Affiliation(s)
- William Hellström
- Department of Paediatrics Institute of Clinical Sciences Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Linnéa Forssell
- Department of Clinical Sciences Lund Paediatrics Lund University Skåne University Hospital Lund Sweden
| | - Eva Morsing
- Department of Clinical Sciences Lund Paediatrics Lund University Skåne University Hospital Lund Sweden
| | - Karin Sävman
- Department of Paediatrics Institute of Clinical Sciences Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
- Region Västra Götaland Department of Neonatology The Queen Silvia Children's Hospital Sahlgrenska University Hospital Gothenburg Sweden
| | - David Ley
- Department of Clinical Sciences Lund Paediatrics Lund University Skåne University Hospital Lund Sweden
| |
Collapse
|
3
|
Carroll PD, Zimmerman MB, Nalbant D, Gingerich EL, An G, Cress GA, Veng-Pedersen P, Widness JA. Neonatal Umbilical Arterial Catheter Removal Is Accompanied by a Marked Decline in Phlebotomy Blood Loss. Neonatology 2020; 117:294-299. [PMID: 32564030 PMCID: PMC7669694 DOI: 10.1159/000506907] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 03/02/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Umbilical arterial catheters (UACs) are frequently used in critically ill neonates. UAC are convenient, reliable, and allow for caregiver convenience in performing painless arterial blood sampling. We hypothesized that UAC removal in extremely low birth weight (ELBW) neonates will result in significantly less phlebotomy blood loss (PBL) after correcting for severity of illness. STUDY DESIGN AND METHODS PBL was measured at a single center in 99 ELBW infants who survived to day 28. Individual infant's paired daily PBL for the two 24-h periods before and after UAC removal were compared using the paired t test. Daily PBL up to 7 days before and 7 days after UAC removal were compared using a logistic regression with mixed model analysis for repeated measures. Cumulative 28-day phlebotomy loss was evaluated by multiple linear regression analysis. RESULTS PBL 24 h before and after UAC removal were 1.7 mL (95% CI 1.5-1.9) and 0.9 mL (95% CI 0.8-1.0; p < 0.0001), respectively. Cumulative 28-day PBL increased by 2.2 mL (±0.7) per day that a UAC was present with or without correction for severity of illness (p < 0.001). CONCLUSION UAC removal is independently associated with a marked decline in PBL. We speculate the ease and convenience of UAC blood sampling lead to more frequent blood testing and greater PBL.
Collapse
Affiliation(s)
- Patrick D Carroll
- Women and Newborn Clinical Program, Intermountain Healthcare, Dixie Regional Medical Center, St. George, Utah, USA
| | - M Bridget Zimmerman
- Department of Biostatistics, College of Public Health, The University of Iowa, Iowa City, Iowa, USA
| | - Demet Nalbant
- Stead Family Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Earl L Gingerich
- Stead Family Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Guohua An
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa College of Pharmacy, Iowa City, Iowa, USA
| | - Gretchen A Cress
- Stead Family Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Peter Veng-Pedersen
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa College of Pharmacy, Iowa City, Iowa, USA
| | - John A Widness
- Stead Family Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA,
| |
Collapse
|
4
|
Puia-Dumitrescu M, Tanaka DT, Spears TG, Daniel CJ, Kumar KR, Athavale K, Juul SE, Smith PB. Patterns of phlebotomy blood loss and transfusions in extremely low birth weight infants. J Perinatol 2019; 39:1670-1675. [PMID: 31582812 PMCID: PMC7331095 DOI: 10.1038/s41372-019-0515-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 07/25/2019] [Accepted: 08/13/2019] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Characterize frequency and volume of blood draws and transfusions in extremely low birth weight infants in the first 10 weeks of life. STUDY DESIGN We included infants with a birth weight <1000 g born 23 0/7-29 6/7 weeks gestational age (GA) and with a length of stay ≥10 weeks, admitted between 2014 and 2016 to a single neonatal intensive care unit. RESULTS Of 54 infants, median (25th, 75th percentile) GA and birth weight were 25 weeks (24, 26) and 665 g (587, 822), respectively. Median number of blood draws per infant decreased from 57 (49, 65) in week 1 to 12 (8, 22) in week 10. Median volume of blood extracted was 83 mL (70, 97), and median number of blood transfusions was 8 (5, 10). CONCLUSIONS This cohort experienced a high number and volume of blood draws. Draw frequency and transfusions decreased over the first 10 weeks of life.
Collapse
Affiliation(s)
- Mihai Puia-Dumitrescu
- Department of Pediatrics, University of Washington, Seattle, WA, USA,Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - David T. Tanaka
- Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | | | | | - Karan R. Kumar
- Department of Pediatrics, Duke University Medical Center, Durham, NC, USA,Duke Clinical Research Institute, Durham, NC, USA
| | - Kamlesh Athavale
- Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Sandra E. Juul
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - P. Brian Smith
- Department of Pediatrics, Duke University Medical Center, Durham, NC, USA,Duke Clinical Research Institute, Durham, NC, USA
| |
Collapse
|
5
|
Robust increases in erythropoietin production by the hypoxic fetus is a response to protect the brain and other vital organs. Pediatr Res 2018; 84:807-812. [PMID: 29895839 PMCID: PMC6291371 DOI: 10.1038/s41390-018-0054-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/16/2018] [Accepted: 03/22/2018] [Indexed: 01/22/2023]
Abstract
Fetal erythropoietin (EPO), in addition to regulating erythropoiesis, has also tissue-protective properties based on its anti-inflammatory, anti-apoptotic, antioxidant, and neurotrophic effects. Notably, EPO concentrations needed for tissue protection are 100-1000 times higher than concentrations needed for regulating erythropoiesis. This dual effect of EPO is based on EPO-receptor (EPO-R) isoforms, which differ structurally and functionally. We hypothesize in this Integrated Mechanism Review that during severe fetal hypoxia the observed, but poorly understood, marked increases of fetal plasma EPO concentrations occur to protect the brain, heart, and other vital fetal organs. We further hypothesize that the concurrent marked increases of EPO in the amniotic fluid during fetal hypoxia, occur to protect newborn infants from necrotizing enterocolitis. This review presents experimental and clinical evidence in support of these hypotheses and points out unknown or poorly understood functions of EPO in the fetus. If these novel hypotheses are correct, the importance of fetal EPO as an antenatal hypoxia biomarker will become apparent. It will also likely point the way to important diagnostic and therapeutic fetal and neonatal interventions.
Collapse
|
6
|
Aysola AE, Duque MA, Williams P, Alissa R. Comparison of heel stick sample with placental blood sample for pretransfusion testing. Transfusion 2018; 58:2227-2231. [PMID: 30153354 DOI: 10.1111/trf.14792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 02/09/2018] [Accepted: 03/25/2018] [Indexed: 11/26/2022]
Abstract
BACKGROUND Published studies demonstrate that placental blood samples provide acceptable results for various laboratory tests, but these studies did not include pretransfusion testing. The aim of this study was to show concordance between heel stick and placental blood sample pairs for pretransfusion testing and to validate tube and gel method for placental samples. Using placental blood samples for pretransfusion testing potentially reduces the amount of blood collected from newborns for initial laboratory tests. STUDY DESIGN AND METHODS Placental samples were collected for pretransfusion tests at birth from 32 newborns with less than 2000 g birthweight and less than 35 weeks to compare the results with the heel stick samples from the same newborns. ABO and D typing, direct antiglobulin test (DAT) with IgG, and antibody screen tests were performed on these sample pairs. For ABO and D typing both tube and gel methods were used to validate both methods for the placental samples. RESULTS This study shows 100% concordance in 32 sample pairs for ABO, D, and DAT tests. Antibody screen results were compared on 29 sample pairs. All 28 sample pairs were concordant, but one placental blood sample was more sensitive to detect a weak maternal antibody than its corresponding heel stick sample was. CONCLUSION The results of this study validated that placental blood samples can be used in place of heel stick samples and are suitable for pretransfusion testing. This study also validated ABO and D typing by tube and gel methods for placental samples.
Collapse
Affiliation(s)
- Agnes E Aysola
- Department of Pathology and Laboratory Medicine, Department of Pediatrics, University of Florida, College of Medicine, Jacksonville, Florida
| | - Miriam Andrea Duque
- Department of Pathology and Laboratory Medicine, Department of Pediatrics, University of Florida, College of Medicine, Jacksonville, Florida
| | - Patty Williams
- Department of Pathology and Laboratory Medicine, Department of Pediatrics, University of Florida, College of Medicine, Jacksonville, Florida
| | - Rana Alissa
- Department of Pathology and Laboratory Medicine, Department of Pediatrics, University of Florida, College of Medicine, Jacksonville, Florida
| |
Collapse
|
7
|
McElroy SJ. Jack Widness: the importance of connections. Pediatr Res 2018; 83:757-759. [PMID: 29244795 DOI: 10.1038/pr.2017.317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 09/22/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Steven J McElroy
- Division of Neonatology, Department of Microbiology and Immunology, Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| |
Collapse
|
8
|
Schmidt RL, Mock DM, Franco RS, Cohen RM, North AK, Cancelas JA, Geisen C, Strauss RG, Vlaar AP, Nalbant D, Widness JA. Antibodies to biotinylated red blood cells in adults and infants: improved detection, partial characterization, and dependence on red blood cell-biotin dose. Transfusion 2017; 57:1488-1496. [PMID: 28261808 PMCID: PMC5567754 DOI: 10.1111/trf.14075] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 01/19/2017] [Accepted: 01/25/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Biotin-labeled red blood cells (BioRBCs) are used for in vivo kinetic studies. Because BioRBC dosing occasionally induces antibodies, a sensitive and specific anti-BioRBC detection assay is needed. STUDY DESIGN AND METHODS Aims were to 1) develop a gel card assay to evaluate existing, naturally occurring and BioRBC-induced plasma antibodies, 2) compare gel card and tube agglutination detection results, and 3) test for a relationship of antibody induction and BioRBC dose. Reagent BioRBCs were prepared using sulfo-NHS biotin ranging from densities 18 (BioRBC-18) to 1458 (BioRBC-1458) µg/mL RBCs. RESULTS Among BioRBC-exposed subjects, gel card and tube agglutination results were concordant in 21 of 22 adults and all 19 infant plasma samples. Gel card antibody detection sensitivity was more than 10-fold greater than tube agglutination. Twelve to 16 weeks after BioRBC exposure, induced anti-antibodies were detected by gel card in three of 26 adults (12%) at reagent densities BioRBC-256 or less, but in none of 41 infants. Importantly, induced anti-BioRBC antibodies were associated with higher BioRBC dose (p = 0.008); no antibodies were detected in 18 subjects who received BioRBC doses less than or equal to BioRBC-18. For noninduced BioRBC antibodies, six of 1125 naïve adults (0.3%) and none of 46 naïve infants demonstrated existing anti-BioRBC antibodies using reagent BioRBC-140 or -162. Existing anti-BioRBCs were all neutralized by biotin compounds, while induced antibodies were not. CONCLUSIONS The gel card assay is more sensitive than the tube agglutination assay. We recommend reagent BioRBC-256 for identifying anti-BioRBCs. Use of a low total RBC biotin label dose (≤ BioRBC-18) may minimize antibody induction.
Collapse
Affiliation(s)
- Robert L. Schmidt
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Donald M. Mock
- Department of Biochemistry & Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR
- Department of Pediatrics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Robert S. Franco
- Department of Internal Medicine, Division of Hematology/Oncology, University of Cincinnati College of Medicine, University of Cincinnati College of Medicine and Medical Service, Cincinnati VA Medical Center, Cincinnati, OH
| | - Robert M. Cohen
- Department of Internal Medicine, Division of Endocrinology, Diabetes & Metabolism, University of Cincinnati College of Medicine and Medical Service, Cincinnati VA Medical Center, Cincinnati, OH
| | | | - José A. Cancelas
- Hoxworth Blood Center and the Department of Pediatrics, The University of Cincinnati, Cincinnati, OH
| | - Christof Geisen
- Institut für Transfusionsmedizin und Immunhämatologie, Klinikum der Goethe Universität, Frankfurt am Main, DRK-Blutspendedienst Baden-Württemberg-Hessen, Germany
| | - Ronald G. Strauss
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR
- Department of Pathology, Carver College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Alexander P. Vlaar
- Department of Intensive Care and Laboratory of Experimental Intensive Care and Anesthesia, Academic Medical Center, Amsterdam, The Netherlands
| | - Demet Nalbant
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR
| | - John A. Widness
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR
| |
Collapse
|
9
|
Kuruvilla DJ, Widness JA, Nalbant D, Schmidt RL, Mock DM, An G, Veng-Pedersen P. Estimation of adult and neonatal RBC lifespans in anemic neonates using RBCs labeled at several discrete biotin densities. Pediatr Res 2017; 81:905-910. [PMID: 28099421 PMCID: PMC5470643 DOI: 10.1038/pr.2017.14] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 11/01/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND Prior conclusions that autologous neonatal red blood cells (RBC) have substantially shorter lifespans than allogeneic adult RBCs were not based on direct comparison of autologous neonatal vs. allogeneic adult RBCs performed concurrently in the same infant. Biotin labeling of autologous neonatal RBCs and allogeneic adult donor RBCs permits concurrent direct comparison of autologous vs. allogeneic RBC lifespan. METHODS RBCs from 15 allogeneic adult donors and from 15 very-low-birth-weight (VLBW) neonates were labeled at separate biotin densities and transfused simultaneously into the 15 neonates. Two mathematical models that account for the RBC differences were employed to estimate lifespans for the two RBC populations. RESULTS Mean ± SD lifespan for adult allogeneic RBC was 70.1 ± 19.1 d, which is substantially shorter than the 120 d lifespan of both autologous and adult allogeneic RBC in healthy adults. Mean ± SD lifespan for neonatal RBC was 54.2 ± 11.3 d, which is only about 30% shorter than that of the adult allogeneic RBCs. CONCLUSION This study provides evidence that extrinsic environmental factors primarily determine RBC survival (e.g., small bore of the capillaries of neonates, rate of oxygenation/deoxygenation cycles) rather than factors intrinsic to RBC.
Collapse
Affiliation(s)
- Denison J. Kuruvilla
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, USA
| | - John A. Widness
- Department of Pediatrics, College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Demet Nalbant
- Department of Pediatrics, College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Robert L. Schmidt
- Department of Pediatrics, College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Donald M. Mock
- Departments of Biochemistry & Molecular Biology and Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Guohua An
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, USA
| | - Peter Veng-Pedersen
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, USA,Corresponding Author: Peter Veng-Pedersen, Ph.D., Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, 115 S. Grand Ave. S227, Iowa City, IA 52242, USA; Tel: (319) 335-8792; Fax: (319) 335-9349;
| |
Collapse
|
10
|
Al‐Ghananim RT, Nalbant D, Schmidt RL, Cress GA, Zimmerman MB, Widness JA. Reticulocyte Hemoglobin Content During the First Month of Life in Critically Ill Very Low Birth Weight Neonates Differs From Term Infants, Children, and Adults. J Clin Lab Anal 2016; 30:326-34. [PMID: 25968472 PMCID: PMC4644110 DOI: 10.1002/jcla.21859] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 04/08/2015] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Reticulocyte hemoglobin content (RET-He)-an established indicator of iron status in children and adults-was determined in very low birth weight (VLBW) infants. METHODS Longitudinal retrospective RET-He data in 26 VLBW neonates during the first month of age were compared with: (a) concurrent complete blood counts (CBCs), including hemoglobin (Hb) concentration, reticulocyte count, and immature reticulocyte fraction (IRF), and erythropoietin (EPO) levels; (b) clinical variables; and (c) RET-He data from the literature for term infants, children, and adults. RESULTS RET-He within 24 hr following birth was 31.8 ± 1.1 pg (mean ± SEM). This was followed by an abrupt, significant decline to 28.3 ± 1.1 pg at 2-4 days, and to steady state levels of 28.4 ± 0.5 pg thereafter. The changes in RET-He were mirrored by changes in plasma EPO, reticulocyte count, and IRF, but not Hb. Steady state RET-He values after 4 days were significantly lower than RET-He values for term infants, children, and adults (31.6 ± 0.11, 32.0 ± 0.12, and 33.0 ± 0.13 pg, respectively). CONCLUSION Although RET-He values in VLBW infant were lower than term infants, children, and adults, the significance and mechanism(s) responsible are unknown. The present VLBW infant data are relevant to investigations assessing hemoglobinization following treatment with recombinant human EPO (r-HuEPO) and/or iron.
Collapse
Affiliation(s)
| | - Demet Nalbant
- Department of PediatricsUniversity of Iowa College of MedicineIowa CityIowa
| | - Robert L. Schmidt
- Department of PediatricsUniversity of Iowa College of MedicineIowa CityIowa
| | - Gretchen A. Cress
- Department of PediatricsUniversity of Iowa College of MedicineIowa CityIowa
| | - M. Bridget Zimmerman
- Department of BiostatisticsCollege of Public HealthUniversity of IowaIowa CityIowa
| | - John A. Widness
- Department of PediatricsUniversity of Iowa College of MedicineIowa CityIowa
| |
Collapse
|
11
|
Carroll PD, Ridout RE. Contemporary Bloodletting--An Opportunity for Collaboration With the Neonatal Intensive Care Unit. Ann Thorac Surg 2015; 100:1976-7. [PMID: 26522571 DOI: 10.1016/j.athoracsur.2015.05.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 04/30/2015] [Accepted: 05/07/2015] [Indexed: 11/24/2022]
Affiliation(s)
- Patrick D Carroll
- Department of Pediatrics, Intermountain Healthcare, Dixie Regional Medical Center, 544 S 400 E, St. George, UT 84770.
| | - R Erick Ridout
- Department of Pediatrics, Intermountain Healthcare, Dixie Regional Medical Center, 544 S 400 E, St. George, UT 84770
| |
Collapse
|
12
|
Kuruvilla DJ, Widness JA, Nalbant D, Schmidt RL, Mock DM, Veng-Pedersen P. A Mass Balance-Based Semiparametric Approach to Evaluate Neonatal Erythropoiesis. AAPS JOURNAL 2015; 18:187-95. [PMID: 26502725 DOI: 10.1208/s12248-015-9831-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 09/25/2015] [Indexed: 11/30/2022]
Abstract
Postnatal hemoglobin (Hb) production in anemic preterm infants is determined by several factors including the endogenous erythropoietin levels, allogeneic RBC transfusions administered to treat anemia, and developmental age. As a result, their postnatal Hb production rate can vary considerably. This work introduces a novel Hb mass balance-based semiparametric approach that utilizes infant blood concentrations of Hb from the first 30 postnatal days to estimate the amount of Hb produced and the erythropoiesis rate in newborn infants. The proposed method has the advantage of not relying on specific structural pharmacodynamic model assumptions to describe the Hb production, but instead utilizes simple mass balance principles and nonparametric regression analysis. The developed method was applied to the Hb data from 79 critically ill anemic very low birth weight preterm infants to evaluate the dynamic changes in erythropoiesis during the first month of life and to determine the inter-subject variability in Hb production. The estimated mean (±SD) cumulative amount of Hb produced by the infants over the first month of life was 6.6 ± 3.4 g (mean body weight, 0.768 kg), and the mean estimated body weight-scaled Hb production rate over the same period was 0.23 ± 0.12 g/day/kg. A significant positive correlation was observed between infant gestational age and the mean body weight-scaled Hb production rate over the first month of life (P < 0.05). We conclude that the proposed mathematical approach and its implementation provide a flexible framework to evaluate postnatal erythropoiesis in newborn infants.
Collapse
Affiliation(s)
- Denison J Kuruvilla
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, 115 S. Grand Ave. S227, Iowa City, Iowa, 52242, USA
| | - John A Widness
- Department of Pediatrics, College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Demet Nalbant
- Department of Pediatrics, College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Robert L Schmidt
- Department of Pediatrics, College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Donald M Mock
- Departments of Biochemistry & Molecular Biology and Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Peter Veng-Pedersen
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, 115 S. Grand Ave. S227, Iowa City, Iowa, 52242, USA.
| |
Collapse
|
13
|
Umbilical Cord Blood-An Untapped Resource: Strategies to Decrease Early Red Blood Cell Transfusions and Improve Neonatal Outcomes. Clin Perinatol 2015; 42:541-56. [PMID: 26250916 DOI: 10.1016/j.clp.2015.04.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Umbilical cord blood is a resource that is available to all neonates. Immediately after delivery of the fetus, cord blood can be used for the direct benefit of the premature infant. Delayed cord clamping and milking of the umbilical cord are 2 methods of transfusing additional fetal blood into the neonate after vaginal or cesarean delivery. Additionally, umbilical cord blood can be utilized for neonatal admission laboratory testing rather than direct neonatal phlebotomy. Together these strategies both increase initial neonatal total blood volume and limit immediate loss through phlebotomy.
Collapse
|
14
|
Carroll PD, Christensen RD. New and underutilized uses of umbilical cord blood in neonatal care. Matern Health Neonatol Perinatol 2015; 1:16. [PMID: 27057333 PMCID: PMC4823695 DOI: 10.1186/s40748-015-0017-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 05/08/2015] [Indexed: 11/21/2022] Open
Abstract
Background In an era increasingly focused on quality improvement and cost containment, more emphasis is being placed on wiser utilization of medical care resources. One underutilized resource in early neonatal care is umbilical cord blood. Findings Umbilical cord blood can be utilized for admission laboratory studies in neonates thereby avoiding a significant phlebotomy event in the first minutes to hours of life. Additionally, umbilical cord blood can also be safely “transfused” into the neonate via delayed cord clamping or milking of the umbilical cord. This has been demonstrated to be particularly beneficial in premature infants by decreasing the rate of intraventricular hemorrhage. Delayed cord clamping has been formally endorsed by a number of medical societies, however it has not yet been universally adopted by obstetricians and neonatologists. Conclusions Both uses of umbilical cord blood for neonatal admission laboratory testing and delayed cord clamping/milking of the umbilical cord have resulted in decreased transfusion rates as well as other outcomes reviewed herein.
Collapse
Affiliation(s)
- Patrick D Carroll
- Women and Newborn's Program, Intermountain Healthcare, Salt Lake City, UT USA ; Neonatal Services, Dixie Regional Medical Center, St. George, UT USA
| | - Robert D Christensen
- Women and Newborn's Program, Intermountain Healthcare, Salt Lake City, UT USA ; Division of Neonatology and Division of Hematology/Oncology, Department of Pediatrics, University of Utah School of Medicine and Primary Children's Hospital, Salt Lake City, UT USA
| |
Collapse
|
15
|
Kuruvilla DJ, Widness JA, Nalbant D, Schmidt RL, Mock DM, Veng-Pedersen P. A Method to Evaluate Fetal Erythropoiesis from Postnatal Survival of Fetal RBCs. AAPS JOURNAL 2015; 17:1246-54. [PMID: 26017162 DOI: 10.1208/s12248-015-9784-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/04/2015] [Indexed: 11/30/2022]
Abstract
Fetal RBCs are produced during a period of very rapid growth and stimulated erythropoiesis under hypoxic intrauterine conditions. Fetal RBC life span varies with gestational age (GA) and is shorter than that in healthy adults. Due to the special kinetic properties of life span-based survival of human RBCs, a mathematical model-based kinetic analysis of the survival of fetal RBCs shortly after birth provides a unique opportunity to "look backward in time" to evaluate fetal erythropoiesis. This work introduces a novel method that utilizes postnatal in vivo RBC survival data collected within 2 days after birth to study both nonsteady-state (non-SS) in utero RBC production and changing fetal RBC life span over time. The effect of changes in erythropoiesis rate and RBC life span and the effect of multiple postnatal phlebotomies on the RBC survival curves were investigated using model-based simulations. This mathematical model, which considers both changes in the rate of erythropoiesis and RBC life span and which accurately accounts for the confounding effect of multiple phlebotomies, was applied to survival curves for biotin-labeled RBCs from ten anemic very low birth weight preterm infants. The estimated mean fetal RBC production rate scaled by body weight was 1.07 × 10(7) RBCs/day g, and the mean RBC life span at birth was 52.1 days; these values are consistent with reported values. The in utero RBC life span increased at a rate of 0.51 days per day of gestation. We conclude that the proposed mathematical model and its implementation provide a flexible framework to study in utero non-SS fetal erythropoiesis in newborn infants.
Collapse
Affiliation(s)
- Denison J Kuruvilla
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, 115 S. Grand Ave. S227, Iowa City, Iowa, 52242, USA
| | | | | | | | | | | |
Collapse
|
16
|
Henry E, Christensen RD, Sheffield MJ, Eggert LD, Carroll PD, Minton SD, Lambert DK, Ilstrup SJ. Why do four NICUs using identical RBC transfusion guidelines have different gestational age-adjusted RBC transfusion rates? J Perinatol 2015; 35:132-6. [PMID: 25254330 DOI: 10.1038/jp.2014.171] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 07/29/2014] [Accepted: 08/04/2014] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To compare neonatal red blood cell (RBC) transfusion rates in four large Intermountain Healthcare NICUs, all of which adhere to the same RBC transfusion guidelines. STUDY DESIGN This retrospective analysis was part of a transfusion-management quality-improvement project. De-identified data included RBC transfusions, clinical and laboratory findings, the anemia-prevention strategies in place in each NICU, and specific costs and outcomes. RESULT Of 2389 NICU RBC transfusions given during the 4-year period studied, 98.9 ± 2.1% (mean ± S.D.) were compliant with our transfusion guidelines, with no difference in compliance between any of the four NICUs. However, RBC transfusion rates varied widely between the four, with averages ranging from 4.6 transfusions/1000 NICU days to 21.7/1000 NICU days (P < 0.00001). Gestational age-adjusted transfusion rates were correspondingly discordant (P < 0.00001). The lower-transfusing NICUs had written anemia-preventing guidelines, such as umbilical cord milking at very low birth weight delivery, use of cord blood for admission laboratory studies, and darbepoetin dosing for selected neonates. Rates of Bell stage ⩾ 2 necrotizing enterocolitis and grade ⩾ 3 intraventricular hemorrhage were lowest in the two lower-transfusing NICUs (P < 0.0002 and P < 0.0016). Average pharmacy costs for darbepoetin were $84/dose, with an average pharmacy cost of $269 per transfusion averted. With a cost of $900/RBC transfusion, the anemia-preventing strategies resulted in an estimated cost savings to Intermountain Healthcare of about $6970 per 1000 NICU days, or about $282,300 annually. CONCLUSION Using transfusion guidelines has been shown previously to reduce practice variability, lower transfusion rates and diminish transfusion costs. Based on our present findings, we maintain that even when transfusion guidelines are in place and adhered to rigorously, RBC transfusion rates are reduced further if anemia-preventing strategies are also in place.
Collapse
Affiliation(s)
- E Henry
- The Women and Newborn's Clinical Program, Salt Lake City, UT, USA
| | - R D Christensen
- The Women and Newborn's Clinical Program, Salt Lake City, UT, USA
| | - M J Sheffield
- The Women and Newborn's Clinical Program, Salt Lake City, UT, USA
| | - L D Eggert
- The Women and Newborn's Clinical Program, Salt Lake City, UT, USA
| | - P D Carroll
- The Women and Newborn's Clinical Program, Salt Lake City, UT, USA
| | - S D Minton
- The Women and Newborn's Clinical Program, Salt Lake City, UT, USA
| | - D K Lambert
- The Women and Newborn's Clinical Program, Salt Lake City, UT, USA
| | - S J Ilstrup
- The Transfusion Medicine Program, Intermountain Healthcare, Salt Lake City, UT, USA
| |
Collapse
|
17
|
Kulshrestha M, Sola-Visner M, Widness JA, Veng-Pedersen P, Mager DE. Mathematical model of platelet turnover in thrombocytopenic and nonthrombocytopenic preterm neonates. Am J Physiol Heart Circ Physiol 2014; 308:H68-73. [PMID: 25362135 DOI: 10.1152/ajpheart.00528.2013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Neonatal thrombocytopenia affects 22-35% of all neonates admitted to neonatal intensive care units. The purpose of this study was to develop a mathematical model for characterizing platelet (PLT) kinetics in thrombocytopenic preterm neonates. Immature PLT fraction (IPF) and PLT counts were measured for up to 35 days after birth in 27 very low birth weight preterm neonates. PLT transfusions were administered to 8 of the 27 (24%) subjects. The final model included a series of four transit compartments to mimic the production and survival of IPF and PLT. Model parameters were estimated using nonlinear mixed effects modeling with the maximum likelihood expectation maximization algorithm. The model adequately captured the diverse phenotypes expressed by individual subject profiles. Typical population survival values for IPF and PLT life spans in nonthrombocytopenic patients were estimated at 0.912 and 10.7 days, respectively. These values were significantly shorter in thrombocytopenic subjects, 0.429 and 2.56 days, respectively. The model was also used to evaluate the influence of growth and laboratory phlebotomy loss on the time course of IPF and PLT counts. Whereas incorporating body weight was essential to correct for expanding blood volume due to growth, phlebotomy loss, a possible covariate, did not significantly influence PLT kinetics. This study provides a platform for identifying potential covariates that influence the interindividual variability in model parameters regulating IPF and PLT kinetics and for evaluating future pharmacological therapies for treating thrombocytopenic neonates.
Collapse
Affiliation(s)
- Mudit Kulshrestha
- Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, New York
| | - Martha Sola-Visner
- Division of Newborn Medicine, Children's Hospital Boston, Boston, Massachusetts
| | - John A Widness
- Department of Pediatrics, College of Medicine, University of Iowa, Iowa City, Iowa; and
| | | | - Donald E Mager
- Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, New York;
| |
Collapse
|
18
|
Pharmacodynamically optimized erythropoietin treatment combined with phlebotomy reduction predicted to eliminate blood transfusions in selected preterm infants. Pediatr Res 2014; 75:336-42. [PMID: 24216541 PMCID: PMC4418561 DOI: 10.1038/pr.2013.213] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 06/18/2013] [Indexed: 11/08/2022]
Abstract
BACKGROUND Preterm very-low-birth-weight (VLBW) infants weighing <1.5 kg at birth develop anemia, often requiring multiple red blood cell transfusions (RBCTx). Because laboratory blood loss is a primary cause of anemia leading to RBCTx in VLBW infants, our purpose was to simulate the extent to which RBCTx can be reduced or eliminated by reducing laboratory blood loss in combination with pharmacodynamically optimized erythropoietin (Epo) treatment. METHODS Twenty-six VLBW ventilated infants receiving RBCTx were studied during the first month of life. RBCTx simulations were based on previously published RBCTx criteria and data-driven Epo pharmacodynamic optimization of literature-derived RBC life span and blood volume data corrected for phlebotomy loss. RESULTS Simulated pharmacodynamic optimization of Epo administration and reduction in phlebotomy by ≥ 55% predicted a complete elimination of RBCTx in 1.0-1.5 kg infants. In infants <1.0 kg with 100% reduction in simulated phlebotomy and optimized Epo administration, a 45% reduction in RBCTx was predicted. The mean blood volume drawn from all infants was 63 ml/kg: 33% required for analysis and 67% discarded. CONCLUSION When reduced laboratory blood loss and optimized Epo treatment are combined, marked reductions in RBCTx in ventilated VLBW infants were predicted, particularly among those with birth weights >1.0 kg.
Collapse
|
19
|
Christensen RD, Carroll PD, Josephson CD. Evidence-based advances in transfusion practice in neonatal intensive care units. Neonatology 2014; 106:245-53. [PMID: 25300949 DOI: 10.1159/000365135] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Transfusions to neonates convey both benefits and risks, and evidence is needed to guide wise use. Such evidence is accumulating, but more information is needed to generate sound evidence-based practices. OBJECTIVE We sought to analyze published information on nine aspects of transfusion practice in neonatal intensive care units. METHODS We assigned 'categories of evidence' and 'recommendations' using the format of the United States Preventive Services Task Force of the Agency for Healthcare Research and Quality. RESULTS The nine practices studied were: (1) delayed clamping or milking of the umbilical cord at preterm delivery - recommended, high/substantial A; (2) drawing the initial blood tests from cord/placental blood from very low birth weight (VLBW, <1,500 g) infants at delivery - recommended, moderate/moderate B; (3) limiting phlebotomy losses of VLBW infants - recommended, moderate/substantial B; (4) selected use of erythropoiesis-stimulating agents to prevent transfusions - recommended, moderate/moderate-moderate/small B, C; (5) using platelet mass, rather than platelet count, in platelet transfusion decisions - recommended, moderate/small C; (6) permitting the platelet count to fall to <20,000/µl in 'stable' neonates before transfusing platelets - recommended, low/small I; (8) permitting the platelet count to fall to <50,000/µl in 'unstable' neonates before transfusing platelets - recommended, moderate/small C, and (9) not performing routine coagulation test screening on every VLBW infant - recommended, moderate/small C. CONCLUSIONS We view these recommendations as dynamic, to be revised as additional evidence becomes available. We predict this list will expand as new studies provide more information to guide best transfusion practices.
Collapse
|
20
|
Bell EF, Nahmias C, Sinclair JC, Zipursky A. Changes in circulating red cell volume during the first 6 weeks of life in very-low-birth-weight infants. Pediatr Res 2014; 75:81-4. [PMID: 24135784 DOI: 10.1038/pr.2013.183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 06/21/2013] [Indexed: 11/09/2022]
Abstract
BACKGROUND Little is known about the change in circulating red cell volume (RCV) of very-low-birth-weight (VLBW) infants during the first weeks of life. METHODS RCV was measured during the first 5 d in 35 VLBW infants using chromium-51 labeling of the infants' red blood cells (RBCs). RCV was measured again at 6 wk of age in 12 infants, and the volumes of RBCs lost by phlebotomy and those gained by transfusion were recorded between the RCV measurements. In six infants, the volume of waste blood on materials contaminated with blood during phlebotomy, which would usually be discarded, was measured by radioactive counting. RESULTS The mean RCV in the first several days of life was 39.6 ml (35.7 ml/kg; range: 20.1-58.7 ml/kg). Of the 12 infants whose RCV was measured twice, all but one had a decrease in absolute RCV. The mean RCV initially and at 6 wk were 37.3 and 26.6 ml, respectively. The mean volume of RBCs lost through phlebotomy was 29.2 ml, and the mean volume of RBCs given by transfusion was 34.5 ml. CONCLUSION During the first 6 wk of life, when the anemia of prematurity is evolving, the RCV falls despite complete replacement of RBCs lost by diagnostic phlebotomy with transfused RBCs.
Collapse
Affiliation(s)
- Edward F Bell
- Department of Pediatrics, University of Iowa, Iowa City, Iowa
| | - Claude Nahmias
- Department of Nuclear Medicine, McMaster University, Hamilton, Ontario, Canada
| | - John C Sinclair
- 1] Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada [2] Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada
| | - Alvin Zipursky
- Programme for Global Paediatric Research, Hospital for Sick Children, Toronto, Ontario, Canada
| |
Collapse
|
21
|
Tracking donor RBC survival in premature infants: agreement of multiple populations of biotin-labeled RBCs with Kidd antigen-mismatched RBCs. Pediatr Res 2013; 74:689-97. [PMID: 24108188 PMCID: PMC3913052 DOI: 10.1038/pr.2013.163] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 05/13/2013] [Indexed: 11/17/2022]
Abstract
BACKGROUND Anemia, a common condition among critically ill premature infants, is affected by red blood cell (RBC) survival (RCS). We hypothesized that transfused allogeneic Kidd antigen-mismatched RBCs would demonstrate the same concurrent RCS tracking as RBCs multilabeled at separate, discrete low densities with biotin (BioRBCs). METHODS Allogeneic RBCs from adult donors were labeled at four biotin densities, mixed, and transfused into 17 anemic premature infants. Nine of the donors and neonates were Kidd antigen mismatched. Serial posttransfusion blood samples were assayed for up to 8 wk by flow cytometry to track the survival of the proportions of Kidd antigen-mismatched and Kidd antigen-biotinylated RBCs. RESULTS Using linear mixed modeling to compare results, RCS of the three lowest BioRBC densities was similar to RCS by Kidd antigen mismatch and to one another. RCS of RBCs labeled at the highest BioRBC density was shortened. CONCLUSION RCS of different populations of RBCs can be tracked concurrently and reliably using the three lowest BioRBC densities. Although comparable RCS results can be achieved using Kidd antigen mismatches, BioRBCs are preferred for investigating neonatal anemia because biotin labeling of both allogeneic and autologous RBCs is possible.
Collapse
|
22
|
Becquet O, Guyot D, Kuo P, Pawlotsky F, Besnard M, Papouin M, Lapillonne A. Respective effects of phlebotomy losses and erythropoietin treatment on the need for blood transfusion in very premature infants. BMC Pediatr 2013; 13:176. [PMID: 24165292 PMCID: PMC4231464 DOI: 10.1186/1471-2431-13-176] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 10/14/2013] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND The benefit to risk ratio of the treatment with erythropoietin (EPO) as a means of limiting the number of transfusions in very preterm infants during hospitalization, seems to be modest since the adoption of restrictive transfusion criteria and of policy limiting phlebotomy losses. We therefore aim to evaluate the factors associated with the number of late blood transfusion in very preterm infants in a unit where the routine use of EPO has been discontinued. METHODS A comparative "before-after" study was carried out in premature infants born before 32 weeks postmenstrual age (PMA), over a period of one year before (EPO group) and one year after (non-EPO group) the discontinuation of EPO therapy. RESULTS A total of 48 infants were included in the study (EPO = 21; non-EPO = 27). The number of infants transfused after the 15 day of life (D15) and the number of transfusions per infant after D15 were not significantly different between the two groups. In a multivariate analysis, the gestational age and the volume of blood drawn off during the first month of life significantly influenced the need for transfusions after the 15th day of life, independently of the treatment with EPO. The hemoglobin levels measured at different times of hospitalization (median postnatal age: 16, 33 and 67 days) were not significantly different between the two groups. CONCLUSIONS Our study shows that the discontinuation of EPO did not change the number of late transfusions. Even when a policy limiting phlebotomy losses is used, blood loss is an important and independent risk factor for late transfusion of very preterm infants.
Collapse
Affiliation(s)
- Odile Becquet
- Department of Neonatology, APHP Necker Hospital, Paris, France
| | - Delphine Guyot
- Department of Neonatology, Territorial Hospital of Tahiti, Papeete, French Polynesia
| | - Philippe Kuo
- Department of Neonatology, Territorial Hospital of Tahiti, Papeete, French Polynesia
| | - Françoise Pawlotsky
- Department of Neonatology, Territorial Hospital of Tahiti, Papeete, French Polynesia
| | - Marianne Besnard
- Department of Neonatology, Territorial Hospital of Tahiti, Papeete, French Polynesia
| | - Micheline Papouin
- Department of Neonatology, Territorial Hospital of Tahiti, Papeete, French Polynesia
| | - Alexandre Lapillonne
- Department of Neonatology, APHP Necker Hospital, Paris, France
- Paris Descartes University, Paris, France
| |
Collapse
|
23
|
Saleh MI, Nalbant D, Widness JA, Veng-Pedersen P. Population pharmacodynamic analysis of erythropoiesis in preterm infants for determining the anemia treatment potential of erythropoietin. Am J Physiol Regul Integr Comp Physiol 2013; 304:R772-81. [PMID: 23485870 DOI: 10.1152/ajpregu.00173.2012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A population pharmacokinetics/pharmacodynamic (PK/PD) model was developed to describe changes in erythropoiesis as a function of plasma erythropoietin (EPO) concentration over the first 30 days of life in preterm infants who developed severe anemia requiring red blood cell (RBC) transfusion. Several covariates were tested as possible factors influencing the responsiveness to EPO. Discarded blood samples in 27 ventilated preterm infants born at 24-29 wk of gestation were used to construct plasma EPO, hemoglobin (Hb), and RBC concentration-time profiles. The amount of Hb removed for laboratory testing and that transfused throughout the study period were recorded. A population PK/PD model accounting for the dynamic Hb changes experienced by these infants was simultaneously fitted to plasma EPO, Hb, and RBC concentrations. A covariate analysis suggested that the erythropoietic efficacy of EPO is increased for preterm infants at later gestational ages. The PD analysis showed a sevenfold difference in maximum Hb production rate dependent on gestational age and indicated that preterm infants, when stimulated by EPO, have the capacity to produce additional Hb that may result in a decrease in RBC transfusions. The present model has utility in clinical trial simulations investigating the treatment potential of erythropoietic stimulating agents in the treatment of anemia of prematurity.
Collapse
Affiliation(s)
- Mohammad I Saleh
- Division of Pharmaceutics, College of Pharmacy, The University of Iowa, Iowa City, IA 52212, USA
| | | | | | | |
Collapse
|
24
|
Rosebraugh MR, Widness JA, Nalbant D, Veng-Pedersen P. A mathematical modeling approach to quantify the role of phlebotomy losses and need for transfusions in neonatal anemia. Transfusion 2012; 53:1353-60. [PMID: 23033916 DOI: 10.1111/j.1537-2995.2012.03908.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Very preterm infants commonly develop anemia requiring multiple red blood cell transfusions (RBCTx). This is in part attributable to heavy laboratory phlebotomy loss. Quantification of the extent to which laboratory blood loss contributes to anemia sufficient to prompt RBCTx has not been examined. STUDY DESIGN AND METHODS Twenty-six preterm infants weighing less than 1500 g at birth requiring ventilator support who received one or more RBCTx were intensively studied during the first month of life. Hemoglobin (Hb) loss via laboratory blood loss and RBC senescence and Hb gain from RBCTx were precisely accounted for in a Hb mass balance mathematical model developed to assess the impact of phlebotomy on RBCTx when restrictive RBCTx criteria were applied. RESULTS Study subjects had a birth weight of 880 ± 240 g (mean ± SD) and a Hb level of 14.4 ± 2.4 g/dL at birth and received 3.81 ± 2.15 RBCTx during the study period. Modeling indicated that even with the total elimination of laboratory phlebotomy loss, a reduction of 41% to 48% in RBCTx was achievable. CONCLUSION The present modeling results indicate that while phlebotomy reduction can significantly decrease the number of RBCTx administered to preterm infants, total elimination of all RBCTx will likely require other approaches, for example, stimulation of erythropoiesis with erythropoiesis-stimulating agents.
Collapse
Affiliation(s)
- Matthew R Rosebraugh
- College of Pharmacy and College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
| | | | | | | |
Collapse
|
25
|
Carroll PD, Widness JA. Nonpharmacological, blood conservation techniques for preventing neonatal anemia--effective and promising strategies for reducing transfusion. Semin Perinatol 2012; 36:232-43. [PMID: 22818543 PMCID: PMC3703659 DOI: 10.1053/j.semperi.2012.04.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The development of anemia after birth in very premature, critically ill newborn infants is a universal well-described phenomenon. Although preventing anemia in this population, along with efforts to establish optimal red blood cell (RBC) transfusion and pharmacologic therapy continue to be actively investigated, the present review focuses exclusively on nonpharmacological approaches to the prevention and treatment of neonatal anemia. We begin with an overview of topics relevant to nonpharmacological techniques. These topics include neonatal and fetoplacental hemoglobin levels and blood volumes, clinical and laboratory practices applied in critically ill neonates, and current RBC transfusion practice guidelines. This is followed by a discussion of the most effective and promising nonpharmacological blood conservation strategies and techniques. Fortunately, many of these techniques are feasible in most neonatal intensive care units. When applied together, these techniques are more effective than existing pharmacotherapies in significantly decreasing neonatal RBC transfusions. They include increasing hemoglobin endowment and circulating blood volume at birth; removing less blood for laboratory testing; and optimizing nutrition.
Collapse
Affiliation(s)
- Patrick D. Carroll
- Women and Newborns Program, Intermountain Healthcare, Division of Neonatology, Dixie Regional Medical Center, St George, UT
| | - John A. Widness
- Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, IA
| |
Collapse
|
26
|
Whyte RK. Neurodevelopmental outcome of extremely low-birth-weight infants randomly assigned to restrictive or liberal hemoglobin thresholds for blood transfusion. Semin Perinatol 2012; 36:290-3. [PMID: 22818550 DOI: 10.1053/j.semperi.2012.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Surviving extremely low-birth-weight infants are at risk of severe neurodevelopmental disability. Transfusion with packed red cells is almost universal in the care of these infants, but the hemoglobin threshold at which these transfusions should be given is unclear. Different clinical trials of restrictive (low hemoglobin) versus liberal (high hemoglobin) thresholds have addressed either neurodevelopmental outcomes at 18-21 months of corrected gestational age or psychological tests and brain imaging at 8-15 years of age. Early follow-up shows differences in cognitive outcome favoring the liberal strategy, but as a post hoc secondary outcome. The childhood studies favor the restrictive strategy, but include major methodological problems of secondary recruitment. No firm conclusion can be reached, other than to report that serious adverse effects may be attributable to one or other of these strategies, that prudent practice is to remain within trial protocols, and that further redesigned clinical trials are required.
Collapse
Affiliation(s)
- Robin K Whyte
- Department of Paediatrics, Dalhousie University, Nova Scotia, Canada.
| |
Collapse
|
27
|
Ohls RK, Roohi M, Peceny HM, Schrader R, Bierer R. A randomized, masked study of weekly erythropoietin dosing in preterm infants. J Pediatr 2012; 160:790-5.e1. [PMID: 22137666 PMCID: PMC3598609 DOI: 10.1016/j.jpeds.2011.10.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 08/17/2011] [Accepted: 10/19/2011] [Indexed: 10/14/2022]
Abstract
OBJECTIVE To compare reticulocyte responses of once-per-week erythropoietin (EPO) dosing with 3-times-a-week dosing in preterm infants. STUDY DESIGN Infants weighing ≤ 1500 g and ≥ 7 days of age were randomized to once-per-week EPO, 1200 U/kg/dose, or 3-times-a-week EPO, 400 U/kg/dose, subcutaneously for 4 weeks, along with iron and vitamin supplementation. Complete blood counts, absolute reticulocyte counts (ARCs), transfusions, phlebotomy losses, and adverse events were recorded. RESULTS Twenty preterm infants (962 ± 55 g, 27.9 ± 0.4 weeks, 17 ± 3 days of age) were enrolled. Groups were similar at baseline. Infants in both groups had increased ARCs, which were similar between treatment groups at the start and end of 4 weeks. Hematocrit remained stable, and similar numbers of transfusions were administered. No adverse effects of either dosing schedule were noted. CONCLUSIONS Preterm infants respond to weekly EPO by increasing ARCs and maintaining hematocrit. We speculate that once-per-week EPO dosing might be beneficial to preterm infants requiring increased erythropoiesis.
Collapse
MESH Headings
- Anemia, Neonatal/diagnosis
- Anemia, Neonatal/drug therapy
- Blood Cell Count
- Cross-Over Studies
- Dose-Response Relationship, Drug
- Drug Administration Schedule
- Erythrocyte Count
- Erythropoiesis/drug effects
- Erythropoietin/administration & dosage
- Female
- Follow-Up Studies
- Hematocrit
- Humans
- Infant, Newborn
- Infant, Premature
- Infant, Premature, Diseases/diagnosis
- Infant, Premature, Diseases/drug therapy
- Infant, Very Low Birth Weight/blood
- Injections, Subcutaneous
- Intensive Care Units, Neonatal
- Iron Compounds/administration & dosage
- Male
- Pilot Projects
- Risk Assessment
- Severity of Illness Index
- Treatment Outcome
- Vitamins/administration & dosage
Collapse
Affiliation(s)
- Robin K Ohls
- Department of Pediatrics, University of New Mexico, Albuquerque, NM, USA.
| | | | | | | | | |
Collapse
|
28
|
Abstract
INTRODUCTION Preterm infants commonly develop anemia requiring red blood cell transfusions (RBCTx). Although an alternative therapy is recombinant human erythropoietin (Epo), it is not widely employed. To provide a rigorous scientific basis supporting the latter approach, a model-based simulation analysis of endogenous erythropoiesis was developed. RESULTS The pharmacodynamic/pharmacokinetic (PK/PD) model identified an optimal Epo dosing algorithm in preterm infants that demonstrated maximal efficacy when Epo was dosed frequently during the early weeks of life (when phlebotomy loss is greatest). Model-based simulations employing optimized Epo dosing predicted that 13 of the 27 (46%) infants would avoid RBCTx ("good responders"). Importantly, simulation results identified five subject-specific covariate factors predictive of good Epo response. DISCUSSION This simulation study provides a basis for possibly eliminating RBCTx in infants who can be selected for optimized Epo therapy. METHODS Epo PD hemoglobin production parameters were determined in 27 preterm infants studied intensively during the first 28 d of life. Model-derived Epo PD parameters were combined with PK parameters derived from the literature to simulate an optimized intravenous Epo bolus dosing schedule. The goal of this simulated optimized schedule was to eliminate RBCTx, as prescribed per current guidelines, in as many preterm infants as possible.
Collapse
|
29
|
Krzyzanski W, Perez Ruixo JJ. Lifespan based indirect response models. J Pharmacokinet Pharmacodyn 2012; 39:109-23. [PMID: 22212685 PMCID: PMC3684441 DOI: 10.1007/s10928-011-9236-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 12/15/2011] [Indexed: 01/18/2023]
Abstract
In the field of hematology, several mechanism-based pharmacokinetic-pharmacodynamic models have been developed to understand the dynamics of several blood cell populations under different clinical conditions while accounting for the essential underlying principles of pharmacology, physiology and pathology. In general, a population of blood cells is basically controlled by two processes: the cell production and cell loss. The assumption that each cell exits the population when its lifespan expires implies that the cell loss rate is equal to the cell production rate delayed by the lifespan and justifies the use of delayed differential equations for compartmental modeling. This review is focused on lifespan models based on delayed differential equations and presents the structure and properties of the basic lifespan indirect response (LIDR) models for drugs affecting cell production or cell lifespan distribution. The LIDR models for drugs affecting the precursor cell production or decreasing the precursor cell population are also presented and their properties are discussed. The interpretation of transit compartment models as LIDR models is reviewed as the basis for introducing a new LIDR for drugs affecting the cell lifespan distribution. Finally, the applications and limitations of the LIDR models are discussed.
Collapse
Affiliation(s)
- Wojciech Krzyzanski
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY, USA.
| | | |
Collapse
|
30
|
Very low birth weight infants qualifying for a 'late' erythrocyte transfusion: does giving darbepoetin along with the transfusion counteract the transfusion's erythropoietic suppression? J Perinatol 2011; 31 Suppl 1:S17-21. [PMID: 21448197 DOI: 10.1038/jp.2010.165] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Red blood cell (RBC) transfusions can suppress erythropoiesis. On this basis, RBC transfusions administered to very low birth weight (VLBW) neonates potentially render them more likely to qualify for a subsequent transfusion. STUDY DESIGN We hypothesized that 'late' (>14 days after birth) RBC transfusions given to VLBW neonates result in a decrease in reticulocyte count persisting for at least 7 to 10 days. We also hypothesized that a single dose of darbepoetin given along with the transfusion would have the opposite effect, increasing the reticulocyte count for at least 7 to 10 days. To test this, we conducted a single-centered randomized trial with 20 VLBW neonates who, according to our transfusion guidelines, qualified for a late transfusion. RESULT VLBW infants about to receive a late RBC transfusion were randomized (1:1) to also receive vs not receive (controls) a single subcutaneous dose of darbepoetin (10 μg kg(-1)). Reticulocyte counts diminished significantly in the controls (a drop of 85±62 × 10(3) μl(-1) (mean±s.d.) at 7 to 10 days), but increased significantly in the darbepoetin recipients (an increase of 177±120 × 10(3) μl(-1) at 7 to 10 days, P<0.0001). At 7 to 10 days after the transfusion, hematocrits of the controls were 8.1±4.9 points above their pre-transfusion values and of the darbepoetin group were 12.4±2.7 points above their pre-transfusion values (P=0.033). CONCLUSION This was a limited-scope, single-centered, randomized trial intended to pilot-test a new concept in neonatal transfusion practice. Namely, we tested whether a late RBC transfusion suppressed reticulocytosis and whether a concomitant single dose of darbepoetin counteracted that suppression. Using the pilot data presented in this study, larger trials can now be designed to address meaningful clinical outcomes such as transfusion avoidance using this approach.
Collapse
|
31
|
Rosebraugh M, Widness JA, Veng-Pedersen P. Receptor-based dosing optimization of erythropoietin in juvenile sheep after phlebotomy. Drug Metab Dispos 2011; 39:1214-20. [PMID: 21460232 DOI: 10.1124/dmd.110.036855] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The primary objective of this work was to determine the optimal time for administration of an erythropoietin (Epo) dose to maximize the erythropoietic effect using a simulation study based on a young sheep pharmacodynamic model. The dosing optimization was accomplished by extending a Hb production pharmacodynamic model, which evaluates the complex dynamic changes in the Epo receptor (EpoR) pool from the changes in Epo clearance. Fourteen healthy 2-month-old sheep were phlebotomized to Hb levels of 3 to 4 g/dl. Epo clearance was evaluated longitudinally in each animal by administering tracer doses of (125)I-recombinant human Epo multiple times during the experiment. Kinetic parameters were estimated by simultaneously fitting to Hb data and Epo clearance data. The phlebotomy caused a rapid temporary increase in the endogenous Epo plasma level. The Hb began to increase after the increased in the Epo level with a lag time of 1.13 ± 0.79 days. The average correlation coefficients for the fit of the model to the Hb and clearance data were 0.953 ± 0.018 and 0.876 ± 0.077, respectively. A simulation study was done in each sheep with fixed individual estimated model parameters to determine the optimal time to administer a 100 U/kg intravenous bolus Epo dose. The optimal dose administration time was 11.4 ± 6.2 days after phlebotomy. This study suggests that the Hb produced from Epo administration can be optimized by considering the dynamic changes in the EpoR pool.
Collapse
Affiliation(s)
- Matthew Rosebraugh
- Department of Pediatrics, University of Iowa, College of Pharmacy, 115 S. Grand Ave., Iowa City, IA 52242, USA
| | | | | |
Collapse
|
32
|
Doshi S, Chow A, Pérez Ruixo JJ. Exposure-response modeling of darbepoetin alfa in anemic patients with chronic kidney disease not receiving dialysis. J Clin Pharmacol 2011; 50:75S-90S. [PMID: 20881221 DOI: 10.1177/0091270010377201] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A population pharmacokinetic and pharmacodynamic model (PK/PD) of darbepoetin alfa following intravenous (IV) or subcutaneous (SC) administration in participants with chronic kidney disease (CKD) was developed. Darbepoetin alfa concentrations from 96 CKD participants, who received IV or SC darbepoetin alfa, and Hgb concentration from 332 CKD participants not on dialysis, who received SC doses of darbepoetin alfa, were used to develop the PK/PD model. An open 2-compartment model with sequential zero- and first-order absorption was used to characterize darbepoetin alfa pharmacokinetics. Darbepoetin alfa was assumed to trigger concentration-dependent stimulation of production of progenitor cells of red blood cells (RBCs) in bone marrow, which become red blood cells and died after life span expiration. Model evaluation was performed through nonparametric bootstrap and posterior predictive checks. Absolute bioavailability, total mean absorption time, clearance, and volume of distribution were estimated to be 44%, 52 h, 3.4 L/d/70 kg, and 5.9 L/70 kg, respectively. The estimates of drug potency, efficacy, and RBC life span were 0.41 ng/mL, 64%, and 77 days, respectively. Pharmacokinetic or pharmacodynamic parameters of darbepoetin alfa were not affected by age and sex. The qualified model supports the use of darbepoetin alfa administered biweekly (SC) in CKD patients for anemia correction and monthly (SC) for hemoglobin maintenance. In addition, the model is deemed appropriate to conduct simulations to support dose selection for additional clinical studies.
Collapse
Affiliation(s)
- Sameer Doshi
- Pharmacokinetics and Drug Metabolism, Amgen, Inc, Thousand Oaks, California, USA
| | | | | |
Collapse
|
33
|
Saleh MI, Widness JA, Veng-Pedersen P. Pharmacodynamic analysis of stress erythropoiesis: change in erythropoietin receptor pool size following double phlebotomies in sheep. Biopharm Drug Dispos 2011; 32:131-9. [PMID: 21456051 DOI: 10.1002/bdd.743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 10/27/2010] [Accepted: 11/23/2010] [Indexed: 11/06/2022]
Abstract
A feedback receptor regulation model was incorporated into a pharmacodynamic model to describe the stimulation of hemoglobin (Hb) production by endogenous erythropoietin (EPO). The model considers the dynamic changes that take place in the EPO receptor (EPOR) pool under phlebotomy-induced anemia. Using a (125)I-rhEPO tracer the EPO clearance changes are evaluated longitudinally prior to and following phlebotomy-induced anemia indirectly to evaluate changes in the EPOR pool size, which has been shown to be linearly related to the clearance. The proposed model simultaneously captures the general behavior of temporal changes in Hb relative to EPO plasma clearance in five lambs (r = 0.95), while accounting for the confounding variables of phlebotomy and changes in the blood volume in the growing animals. The results indicate that under anemia the EPOR pool size is up-regulated by a factor of nearly two over baseline and that the lowest and highest EPOR pool sizes differ by a factor of approximately four. The kinetic model developed and the data-driven mechanism proposed serves as a starting point for developing an optimal EPO dosing algorithm for the treatment of neonatal anemia.
Collapse
Affiliation(s)
- Mohammad I Saleh
- Division of Pharmaceutics, College of Pharmacy, The University of Iowa, Iowa City, USA
| | | | | |
Collapse
|
34
|
Mock DM, Matthews NI, Zhu S, Strauss RG, Schmidt RL, Nalbant D, Cress GA, Widness JA. Red blood cell (RBC) survival determined in humans using RBCs labeled at multiple biotin densities. Transfusion 2010; 51:1047-57. [PMID: 21062290 DOI: 10.1111/j.1537-2995.2010.02926.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Safe, accurate methods permitting simultaneous and/or repeated measurement of red blood cell (RBC) survival (RCS) are important to investigate pathophysiology and therapy of anemia. Methods using chromium 51 ((51) Cr)-labeled RBCs are unacceptable for infants, children, and pregnant women. We report RCS measured in vivo using RBCs labeled with several densities of biotin (BioRBCs). STUDY DESIGN AND METHODS Aliquots of autologous RBCs from eight healthy adult subjects were labeled separately at four discrete biotin densities, mixed, and infused. The proportion of each population of BioRBCs circulating was determined serially by flow cytometry over 20 weeks. For each population, RCS was assessed by the following: 1) posttransfusion BioRBC recovery at 24 hours (PTR(24) ); 2) time to decrease to 50% of the enrichment at 24 hours (T(50) ); and 3) mean potential lifespan (MPL). RESULTS Among the four BioRBC densities, no significant differences in PTR(24) were observed. T(50) and MPL were similar for the two lowest BioRBC densities. In contrast, the two highest BioRBC densities demonstrated progressively decreased T(50) and MPL. CONCLUSIONS RBCs labeled at four biotin densities can be used to independently and accurately measure PTR(24 ) and two lowest biotin densities can accurately quantitate long-term RCS. This method provides a tool for investigating anemia in infants, fetuses, and pregnant women with the following advantages over the standard (51) Cr method: 1) study subjects are not exposed to radiation; 2) small blood volumes (e.g., 20 µL) are required; and 3) multiple independent RCS measurements can be made simultaneously in the same individual.
Collapse
Affiliation(s)
- Donald M Mock
- Department of Biochemistry & Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Christensen RD, Lambert DK, Baer VL, Montgomery DP, Barney CK, Coulter DM, Ilstrup S, Bennett ST. Postponing or eliminating red blood cell transfusions of very low birth weight neonates by obtaining all baseline laboratory blood tests from otherwise discarded fetal blood in the placenta. Transfusion 2010; 51:253-8. [DOI: 10.1111/j.1537-2995.2010.02827.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|