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Dive into the research topics where B C MacQueen is active.

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Featured researches published by B C MacQueen.


Journal of Perinatology | 2017

The iron status at birth of neonates with risk factors for developing iron deficiency: a pilot study

B C MacQueen; Robert D. Christensen; D M Ward; S T Bennett; E A O'Brien; M J Sheffield; V L Baer; G L Snow; K A Weaver Lewis; R E Fleming; J Kaplan

Objective:Small-for-gestational-age (SGA) neonates, infants of diabetic mothers (IDM) and very-low-birth weight premature neonates (VLBW) are reported to have increased risk for developing iron deficiency and possibly associated neurocognitive delays.Study Design:We conducted a pilot study to assess iron status at birth in at-risk neonates by measuring iron parameters in umbilical cord blood from SGA, IDM, VLBW and comparison neonates.Results:Six of the 50 infants studied had biochemical evidence of iron deficiency at birth. Laboratory findings consistent with iron deficiency were found in one SGA, one IDM, three VLBW, and one comparison infant. None of the infants had evidence of iron deficiency anemia.Conclusions:Evidence of biochemical iron deficiency at birth was found in 17% of screened neonates. Studies are needed to determine whether these infants are at risk for developing iron-limited erythropoiesis, iron deficiency anemia or iron-deficient neurocognitive delay.


Blood Cells Molecules and Diseases | 2017

Two novel mutations in TMPRSS6 associated with iron-refractory iron deficiency anemia in a mother and child

Hassan M. Yaish; Colin P. Farrell; Robert D. Christensen; B C MacQueen; Laurie K. Jackson; Jesus Trochez-Enciso; Jerry Kaplan; Diane M. Ward; Walid K. Salah; John D. Phillips

In an iron deficient child, oral iron repeatedly failed to improve the condition. Whole exome sequencing identified one previously reported plus two novel mutation in the TMPRSS6 gene, with no mutations in other iron-associated genes. We propose that these mutations result in a novel variety of iron-refractory iron deficiency anemia.


Journal of Perinatology | 2018

Reference intervals for stool calprotectin in preterm neonates and their utility for the diagnosis of necrotizing enterocolitis

B C MacQueen; Robert D. Christensen; C. C. Yost; P. V. Gordon; V. L. Baer; R. Schlaberg; J. Lowe

ObjectiveCalprotectin is an antimicrobial protein found in stool when released by granulocytes. We sought to create stool calprotectin reference ranges in preterm neonates and to evaluate whether levels exceeding the upper reference interval are diagnostic for necrotizing enterocolitis (NEC).Study designStool calprotectin was measured in premature neonates without gastrointestinal pathology to create reference intervals. For comparison, levels from infants undergoing “rule out NEC” evaluations were plotted on these reference intervals.ResultsStool calprotectin reference intervals were created according to gestational age at birth and corrected gestational age. Levels during “rule out NEC” evaluations were more often above the upper reference interval with NEC vs. those without NEC.ConclusionsStools from preterm neonates have a higher range of calprotectin than stools from healthy term neonates. In evaluating preterm neonates for NEC with stool calprotectin, a calprotectin upper reference interval that incorporates corrected gestational age best predicts the diagnosis of NEC.


Journal of Perinatology | 2017

Recombinant tissue plasminogen activator to restore catheter patency: efficacy and safety analysis from a multihospital NICU system

D M Scott; Con Yee Ling; B C MacQueen; Vickie L. Baer; E Gerday; Robert D. Christensen

Objective:In 2001, the US Food and Drug Administration approved recombinant tissue plasminogen activator (alteplase, Cathflo Activase) to reestablish patency of central catheters occluded, presumably, by a fibrin clot. We conducted a multicenter quality improvement study to determine the value of this procedure in our Neonatal Intensive Care Unit (NICUs), including analyses of efficacy, safety and costs.Study Design:We conducted a retrospective quality analysis of neonates in level III NICUs, who received alteplase for the purpose of reestablishing patency of occluded central catheters.Results:Alteplase was administered to 169 neonates, each given one to four doses, totaling 205 episodes of administration. The most common type of catheter where alteplase was used was percutaneously inserted central catheter (PICC) lines (78% of uses), 8% were umbilical venous catheters (UVCs), 6% arterial lines, 5% chest tubes and 3% other catheters. Postnatal age at first dose ranged from 0 to 132 days (median, 12); dosed patients were 22 to 41 weeks gestation at birth (median, 31). Fifty-eight percentage of administrations restored catheter function. Success was more likely at younger postnatal age (10±2 days old in successful vs 14±1 days in unsuccessful treatments; P=0.023). Seventy-two percentage of the re-canalized catheters remained functional until they were no longer needed (2 to 30 days later). Nine percentage of episodes were treated with a second dose 1 to 17 days later for re-occlusion and 50% of those were successful. Bleeding consequences were identified in only one case, where three separate lines were treated (chest tube, PICC and UVC) within a 6-h period. Costs to the health system of doses, minus savings to the system by not needing to replace lines, averaged a net of


Neonatology | 2019

Automated Quantification of Fragmented Red Blood Cells: Neonatal Reference Intervals and Clinical Disorders of Neonatal Intensive Care Unit Patients with High Values.

Allison J Judkins; B C MacQueen; Robert D. Christensen; Erick Henry; Gregory L. Snow; Sterling T. Bennett

34 per dose.Conclusions:The apparent safety and favorable value analysis prompted us to develop a consistent approach to alteplase usage in the Intermountain Healthcare NICUs, using the data in this report to standardize the guidelines across our health system.


Neonatology | 2018

Non-Immune Hydrops, Hypotonia, Encephalopathy, and Liver Failure with Novel Compound Heterozygous AHCY Mutations.

Allison J Judkins; B C MacQueen; Robert D. Christensen; Jessica Comstock; Rong Mao; Josue Flores-Daboub

Background: Schistocytes are circulating erythrocyte fragments. They can be identified microscopically from a blood smear; but automated systems evaluate more cells and avoid inconsistencies in microscopy. Studies using adult subjects indicate that automated quantification of schistocytes can be clinically useful. However, reference intervals for automated schistocyte counts of neonates have not been published, and the relevance of a high automated schistocyte count from neonates has not been reported. Objectives: Using retrospective automated neonatal complete blood count (CBC) data, we created reference intervals for fragmented red cells (FRCs) and sought to discover the clinical conditions of neonates with high FRCs (above the upper reference interval). Results: We created reference intervals based on 39,949 CBCs from 15,655 neonates 0–90 days old. The lower reference interval was 0 FRC/µL and the upper interval was 100,000/µL. The highest FRCs (96 CBCs from 44 neonates) were > 250,000/µL. These neonates clustered into the following groups: 37% had sepsis, 29% had disseminated intravascular coagulation (DIC), 17% had a genetic syndrome, 14% necrotizing enterocolitis (NEC), and 7% had iron deficiency (some had more than one diagnosis). Based on the reference intervals, we divided the 39,949 FRC values into 3 groups: (1) < 100,000/µL (“normal”), (2) 100,000–200,000/µL (“moderately elevated”), and (3) > 200,000/µL (“extremely elevated”). The odds that a microangiopathic condition (DIC, sepsis, NEC) or a microcytic disorder (iron deficiency) were present were significantly higher in the moderately elevated, and more so in the extremely elevated group. Conclusions: Our study suggests that a high FRC could prompt investigation into, or inform follow-up of, a neonatal microangiopathic or extremely microcytic disorder.


Journal of Perinatology | 2018

ABO hemolytic disease of the fetus and newborn: thirteen years of data after implementing a universal bilirubin screening and management program

Robert D. Christensen; Vickie L. Baer; B C MacQueen; Elizabeth A. O’Brien; S. J. Ilstrup

A late-preterm infant with a prenatal diagnosis of non-immune hydrops was born with hypotonia, poor respiratory effort, chylothorax, encephalopathy, coagulopathy, progressive hepatic failure, and refractory pulmonary hypertension. Life support was withdrawn at 7 days of life due to multisystem organ failure. Rapid whole exome sequencing revealed novel compound heterozygous mutations in the gene encoding S-adenosylhomocysteine hydrolase (AHCY); each novel variant was carried by an asymptomatic parent. Reports of neonates with other AHCY mutations describe a pathology of varying severity. AHCY mutations should be considered when seeking an etiology for neonates with the combination of non-immune hydrops, hypotonia, encephalopathy, and liver failure.


Journal of Perinatology | 2017

The immature platelet fraction: creating neonatal reference intervals and using these to categorize neonatal thrombocytopenias

B C MacQueen; Robert D. Christensen; Erick Henry; A M Romrell; Theodore J. Pysher; S T Bennett; Martha Sola-Visner

ObjectiveABO hemolytic disease occurs among neonates with blood groups A or B delivered to group O women. Extreme neonatal hyperbilirubinemia due to ABO disease has been reported, but its frequency is not well known. We sought to determine the odds of developing severe ABO hemolytic disease in the 13 years since adopting universal bilirubin screening/management in the Intermountain Healthcare system.Study designWe conducted a retrospective analysis of neonates born between 2004 and 2016, defining “severe hemolytic disease” as; (1) total serum bilirubin (TSB) >25 mg/dL, or (2) hospital readmission for jaundice, or (3) bilirubin encephalopathy. Neonates born to group O (+) mothers were included and considered either; (1) Controls (not at risk for ABO disease because they were group O), (2) Study subjects (at risk for ABO disease because they were group A or B).ResultsOf 400,531 live births, 47% were to group O women; 86% of whom were group O (+). Overall, 42,529 (27%) neonates born to group O (+) women had their blood group determined; 29,729 (68%) were O, 10,682 (25%) A, and 3109 (7%) B. Peak TSBs during the first 10 days were higher in group A (11.0 ± 4.2 mg/dL) and B (11.5 ± 4.3) than group O neonates (10.3 ± 4.1). However the relative risks of a TSB ≥25 mg/dL, readmission for jaundice, or kernicterus, were the same in the control vs. study groups.ConclusionsIn our health system, severe hemolytic disease in neonates born to group O (+) woman is not more likely in group A or B neonates than in controls (group O). We recognize that in other practices, particularly those who do not have a universal bilirubin screening/management program, ABO hemolytic disease severity might be different than in our system.


Global pediatric health | 2017

Iron Supplements for Infants at Risk for Iron Deficiency

B C MacQueen; Vickie L. Baer; Danielle M. Scott; Con Yee Ling; Elizabeth A. O’Brien; Caitlin Boyer; Erick Henry; Robert E. Fleming; Robert D. Christensen

Objective:The immature platelet fraction (IPF) is a laboratory measurement analogous to the reticulocyte count, but reflecting the thrombopoietic state. Similar to a reticulocyte count, it can be expressed as a percent (IPF%=percent of platelets that are immature) or as an absolute number per μl blood; the immature platelet count (IPC=IPF% × platelets per μl of blood).Study design:Using a retrospective analysis of de-identified data from non-thrombocytopenic neonates, we created reference intervals for IPF% and IPC. We then tested the value of these measurements for categorizing thrombocytopenic neonates.Results:New charts display reference intervals for IPF% and IPC on the day of birth according to gestational age, and during the first 90 days after birth. Neonates with hyporegenerative varieties of thrombocytopenias (syndromes, small for gestational age, birth asphyxia) had lower IPF% and IPC than did neonates with consumptive thrombocytopenias (immune-mediated, infection, disseminated intravascular coagulation, necrotizing enterocolitis; both P<0.0001).Conclusion:The new reference interval charts can be used to recognize abnormal IPFs. The IPF parameters can help clarify the kinetic mechanism responsible for thrombocytopenias in neonates.


Journal of Perinatology | 2016

Comparing automated vs manual leukocyte differential counts for quantifying the 'left shift' in the blood of neonates.

B C MacQueen; Robert D. Christensen; Bradley A. Yoder; Erick Henry; Vickie L. Baer; S T Bennett; H M Yaish

Professional societies have published recommendations for iron dosing of preterm neonates, but differences exist between guidelines. To help develop standardized guidelines, we performed a 10-year analysis of iron dosing in groups at risk for iron deficiency: IDM (infants of diabetic mothers), SGA (small for gestational age), and VLBW premature neonates (very low birth weight, <1500 g). We analyzed iron dosing after red cell transfusions and erythropoiesis-stimulating agents (ESA). Of IDM, 11.8% received iron in the hospital; 9.8% of SGA and 27.1% of VLBW neonates received iron. Twenty percent of those who received iron had it started by day 14; 63% by 1 month. Supplemental iron was stopped after red cell transfusions in 73% of neonates receiving iron. An ESA was administered to 1677, of which 33% received iron within 3 days. This marked variation indicates that a consistent approach is needed, and using this report and a literature review, we standardized our iron-dosing guidelines.

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Vickie L. Baer

Intermountain Healthcare

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Erick Henry

Intermountain Healthcare

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S T Bennett

Primary Children's Hospital

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P. V. Gordon

Boston Children's Hospital

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