Accuracy of single intravenous access iohexol GFR in children is hampered by marker contamination

AbstractMeasurement of glomerular filtration rate (GFR) in children by iohexol injection and blood sampling from the contralateral arm is widely used. A single intravenous access for iohexol injection and subsequent blood sampling has the obvious advantages of being less painful and easier to perform. The purpose of our study was to determine if blood samples drawn from the injection access are feasible and accurate for iohexol GFR (iGFR) measurements. Thirty-one children, median age 10.5 (range 6–17) years, with chronic kidney disease were given a bolus of iohexol followed by extended saline flushing and subsequent venous blood samples collected from the injection access as well as from a cannula in the contralateral arm, the latter serving as the reference method. Paired venous blood samples were collected at four time points (2, 3, 3.5 and 4 h) after the iohexol bolus. Blood sample discarding preceded and saline flushing followed each blood sampling to avoid marker contamination. iGFR based on samples drawn from the injection access at 2 and 3 h showed significantly lower iGFR than measurement from the contralateral arm (p < 0.01). Singlepoint iGFR did not differ significantly after 3–4 repeated procedures of blood discarding and saline flusing (3.5 and 4 h). Despite thorough saline flushing there is still a relatively high risk of falsely low iGFR due to marker contamination in blood samples from the injection site. Hence, blood sampling from a second intravenous access is recommended for routine iohexol GFR measurements in children.Clinical trial registration: ClinicalTrials.gov, Identifier NCT01092260, https://clinicaltrials.gov/ct2/show/NCT01092260?term=tondel&rank=2.

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POS1398 RHEUMATOLOGICAL PATIENTS PERFORMING BLOOD SELF-SAMPLING FOR DMARD THERAPY SAFETY: A PROOF OF CONCEPT STUDY COMPARING WITH VENOUS BLOOD SAMPLES

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.2927 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 982.1-982

Author(s):

S. A. Just ◽

P. Toftegaard ◽

U. Jakobsen ◽

T. R. Larsen

Keyword(s):

Venous Blood ◽

Automated Analysis ◽

Blood Sampling ◽

Differential Count ◽

Blood Samples ◽

Reactive Protein ◽

Dmard Treatment ◽

Patient Reported ◽

Venous Sample ◽

Treatment Safety

Background:Regular blood sampling is a requirement for rheumatological patients receiving csDMARD, bDMARD or tsDMARD therapies (1). The frequent blood sampling affects the patient’s life as they use a substantial amount of time at hospitals or by the general practitioner. Often visits are time-consuming with transport, waiting time, and for some patient’s costly long travels. Giving patients the option of taking the blood samples themself in their own home, as part of a patient-centred monitoring approach, could provide the patient much higher degree of independence. Further, it may increase the quality of life, cause higher compliance with taking the control samples and possibly reduce health care costs.Objectives:1. To investigate if rheumatological patients can take capillary blood samples and describe patient-reported outcomes (PRO) about the procedure. 2. Compare the venous and capillary samples’ results. 3. Test if the laboratory automated analysis equipment can handle the small capillary samples.Methods:21 rheumatological patients, underwent capillary and venous blood sampling at up to 4 occasions (1-2 months between). Instructions were available on a pictogram. PRO data were assessed by questionnaires. The patient performed blood extraction to the capillary samples from a finger after using a device making a small incision (2 mm depth and 3 mm width). Two capillary tubes (one Microtainer K2-EDTA and one Microtainer lithium heparin with gel) were filled with a total volume of approximately 1.0 mL blood. A phlebotomist took the venous sample. Blood samples were analyzed for alanine aminotransferase (ALAT), albumin, alkaline phosphatase (ALP), calcium, C-reactive protein (CRP), creatinine, potassium, lactate dehydrogenase (LDH), urate, hemolysis index, erythrocyte corpuscular volume (MCV), haemoglobin, leukocytes, differential count and platelets.Results:A total of 53 paired capillary (C) and venous (V) samples were taken. The average perceived pain of the procedure of C sampling was VAS: 10.3 (SD:14.4) (0-100) versus V sampling VAS: 8.5 (SD:11.7). 90% of patients would accept it as a future form of blood sampling.Differences in blood samples (C versus V) were: CRP (-3.4%); Hemoglobin (-1.4%); Creatinine (-4.4%), ALAT (-2.9%), neutrophils (1.43%), platelets (-16.9%).The index of hemolysis was on average 128.9 mg/dL (SD: 203) in C versus 6.7 mg/dL (SD: 4.6) in V. Results was evaluated by a rheumatologist, and 92.5% of capillary samples could be used to evaluate the safety of DMARD treatment based on the most critical samples for this: ALAT, creatinine, neutrophils and platelets (1). The 7.5 % not accepted were all due to aggregated platelets leading to low platelet count. There was hemolysis in 18% of the samples, but the analysis results could be used despite this.Conclusion:In the majority of rheumatological patients, capillary self-sampling is well tolerated.We show that it is possible to extract the needed results from the capillary samples to evaluate DMARD treatment safety, despite higher hemolysis index. Using capillary samples taken at home could be a central instrument in future rheumatological patient-centred monitoring.References:[1]Rigby WFC et al. Review of Routine Laboratory Monitoring for Patients with Rheumatoid Arthritis Receiving Biologic or Nonbiologic DMARDs. Int J Rheumatol. 2017Disclosure of Interests:None declared

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Recovery-Stress Response of Blood-Based Biomarkers

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18115776 ◽

2021 ◽

Vol 18 (11) ◽

pp. 5776

Author(s):

Sebastian Hacker ◽

Thomas Reichel ◽

Anne Hecksteden ◽

Christopher Weyh ◽

Kristina Gebhardt ◽

...

Keyword(s):

Calcium Binding ◽

Tissue Repair ◽

Elite Athletes ◽

Venous Blood ◽

Soccer Players ◽

Recovery Stress ◽

Blood Samples ◽

Time Points ◽

S100 Calcium Binding Protein ◽

Stress States

The purpose of this study was to investigate blood-based biomarkers and their regulation with regard to different recovery-stress states. A total of 35 male elite athletes (13 badminton, 22 soccer players) were recruited, and two venous blood samples were taken: one in a ‘recovered’ state (REC) after a minimum of one-day rest from exercise and another one in a ‘non-recovered’ state (NOR) after a habitual loading microcycle. Overall, 23 blood-based biomarkers of different physiologic domains, which address inflammation, muscle damage, and tissue repair, were analyzed by Luminex assays. Across all athletes, only creatine kinase (CK), interleukin (IL-) 6, and IL-17A showed higher concentrations at NOR compared to REC time points. In badminton players, higher levels of CK and IL-17A at NOR were found. In contrast, a higher value for S100 calcium-binding protein A8 (S100A8) at REC was found in badminton players. Similar differences were found for BDNF in soccer players. Soccer players also showed increased levels of CK, and IL-6 at NOR compared to REC state. Several molecular markers were shown to be responsive to differing recovery-stress states, but their suitability as biomarkers in training must be further validated.

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Blood Glucose Assay Using Dextrostix and a Reflectance Meter

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456327200900144 ◽

1972 ◽

Vol 9 (1-6) ◽

pp. 91-94 ◽

Cited By ~ 6

Author(s):

I. W. Percy-Robb ◽

R. S. McMaster ◽

A. D. B. Harrower ◽

L. J. P. Duncan

Keyword(s):

Blood Glucose ◽

Venous Blood ◽

Reference Method ◽

Capillary Blood ◽

Blood Samples ◽

Laboratory Staff ◽

Glucose Assay ◽

Reflectance Meter ◽

High Degree ◽

Blood Glucose Concentrations

The ‘Dextrostix’-reflectance meter system for blood glucose analysis has been evaluated using a blood glucose reference method. A high degree of concordance between the two methods was obtained when analyses were performed by skilled laboratory staff on venous blood samples containing fluoride, with a 75 s contact time. Skilled laboratory staff performed significantly better than unskilled staff. Capillary blood glucose concentrations correlated poorly with concentrations in venous blood samples taken at the same time as the capillary blood.

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Point-of-care microvolume cytometer measures platelet counts with high accuracy from capillary blood

PLoS ONE ◽

10.1371/journal.pone.0256423 ◽

2021 ◽

Vol 16 (8) ◽

pp. e0256423

Author(s):

William M. Dickerson ◽

Rebecca Yu ◽

Helena U. Westergren ◽

Jonathan Paraskos ◽

Philipp Schatz ◽

...

Keyword(s):

Point Of Care ◽

Venous Blood ◽

Reference Method ◽

Time Data ◽

Platelet Recovery ◽

Blood Samples ◽

Impedance Analyzer ◽

Platelet Counts ◽

Platelet Antibodies ◽

Care Assessment

Background Point-of-care (PoC) testing of platelet count (PLT) provides real-time data for rapid decision making. The goal of this study is to evaluate the accuracy and precision of platelet counting using a new microvolume (8 μL), absolute counting, 1.5 kg cytometry-based blood analyzer, the rHEALTH ONE (rHEALTH) in comparison with the International Society of Laboratory Hematology (ISLH) platelet method, which uses a cytometer and an impedance analyzer. Methods Inclusion eligibility were healthy adults (M/F) ages 18–80 for donation of fingerprick and venous blood samples. Samples were from a random N = 31 volunteers from a single U.S. site. Samples were serially diluted to test thrombocytopenic ranges. Interfering substances and conditions were tested, including RBC fragments, platelet fragments, cholesterol, triglycerides, lipids, anti-platelet antibodies, and temperature. Results The concordance between the rHEALTH and ISLH methods had a slope = 1.030 and R2 = 0.9684. The rHEALTH method showed a correlation between capillary and venous blood samples (slope = 0.9514 and R2 = 0.9684). Certain interferents changed platelet recovery: RBC fragments and anti-platelet antibodies with the ISLH method; platelet fragments and anti-platelet antibodies on the rHEALTH; and RBC fragments, platelets fragments, triglycerides and LDL on the clinical impedance analyzer. The rHEALTH’s precision ranged from 3.1–8.0%, and the ISLH from 1.0–10.5%. Conclusions The rHEALTH method provides similar results with the reference method and good correlation between adult capillary and venous blood samples. This demonstrates the ability of the rHEALTH to provide point-of-care assessment of normal and thrombocytopenic platelet counts from fingerprick blood with high precision and limited interferences.

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Accuracy and precision of analyses for total cholesterol as measured with the Reflotron cholesterol method.

Clinical Chemistry ◽

10.1093/clinchem/35.8.1734 ◽

1989 ◽

Vol 35 (8) ◽

pp. 1734-1739 ◽

Cited By ~ 21

Author(s):

P S Bachorik ◽

R H Bradford ◽

T Cole ◽

I Frantz ◽

A M Gotto ◽

...

Keyword(s):

Plasma Cholesterol ◽

Venous Blood ◽

Reference Method ◽

Capillary Blood ◽

Average Difference ◽

Blood Samples ◽

Laboratory Values ◽

Accuracy And Precision ◽

Single Finger ◽

Made In

Abstract We compared plasma cholesterol measurements made with the Boehringer Mannheim Reflotron reflectance photometric analyzer in 1298 capillary blood samples with measurements made in venous blood samples collected at the same time and analyzed in four standardized Lipid Research Clinics laboratories. The Reflotron measurements averaged 0.8% to 7.8% lower than the laboratory values. Correlations (r) between the two sets of measurements ranged from 0.92 to 0.96. In some samples, however, the Reflotron values differed from the laboratory values by greater than or equal to 12%; the cholesterol concentrations in these samples tended to be higher than in those for which better agreement was observed. The smaller negative biases were observed when test strips were used that were calibrated with reference to the Centers for Disease Control Reference Method for cholesterol. The agreement between sequential Reflotron values averaged less than or equal to 4.3%. There was an average difference of less than or equal to 1.0% between Reflotron measurements made in each of two sequential capillary blood samples taken from a single finger puncture.

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Day-to-day variation in iron-status measures in young iron-deplete women

British Journal Of Nutrition ◽

10.1079/bjn20051461 ◽

2005 ◽

Vol 94 (4) ◽

pp. 551-556 ◽

Cited By ~ 17

Author(s):

Anita Belza ◽

Marianne Henriksen ◽

Annette K Ersbøll ◽

Shakuntala H Thilsted ◽

Inge Tetens

Keyword(s):

Menstrual Cycle ◽

Observational Studies ◽

Iron Status ◽

Venous Blood ◽

Blood Sampling ◽

Volume Distribution ◽

Distribution Width ◽

Blood Samples ◽

Significance Level ◽

True Value

In intervention and observational studies, it is necessary to determine the number of blood samples required to estimate the true value of Fe-status measures. The aim of the present study was to determine the number of days for blood sampling required in order to measure the ‘true value’ of five Fe-status parameters in young Fe-depleted women and to investigate the effect of menstrual cycle on these measures. Twelve women (aged 23–30 years), non-anaemic but with low Fe stores, participated in the study. Venous blood samples were collected under standardised conditions on fifteen non-consecutive days during a 5-week period. All blood samples were analysed for Hb, serum ferritin (SF), serum transferrin receptors (sTfR), red blood cell volume distribution width (RDW) and reticulocytes (RET), and body Fe stores were calculated as the ratio between sTfR and SF. No systematic changes were found in the investigated parameters during the study. When analytical variations were accounted for, the day-to-day variations (CV%) were as follows: Hb 2·9 %, SF 8·2 %, RET 26·0 %, RDW 2·4 % and sTfR 8·1 %. Calculating the ‘true value’ with a 5 % significance level and 80 % power showed that one blood sample was sufficient for Hb, SF, sTfR and RDW, whereas seven blood-sampling days were needed for RET. In this study, no significant differences in Fe status were found across the menstrual cycle. The conclusions from this study are valid for studies conducted under similar strict conditions.

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Evaluation of blood electrolyte alterations in cats during elec-tive laparoscopic ovariectomy

Cluj Veterinary Journal ◽

10.52331/cvj.v26i2.26 ◽

2021 ◽

Vol 26 (2) ◽

pp. 1-8

Author(s):

Iulia Melega ◽

Lucia Victoria Bel ◽

Cosmina Andreea Dejescu ◽

Madalina Florina Dragomir ◽

Bogdan Sevastre ◽

...

Keyword(s):

Carbon Dioxide ◽

Venous Blood ◽

Electrolyte Imbalance ◽

Anaesthesia Induction ◽

Blood Samples ◽

Time Points ◽

Blood Electrolytes ◽

Carbon Dioxide Pneumoperitoneum ◽

Blood Ph ◽

K Concentration

In a clinical setting, we tested the hypothesis of whether hypercapnia developed during carbon dioxide pneumoperitoneum is associated with changes in blood electrolytes. This prospective study involved ten female cats that underwent elective laparoscopic ovariectomy. Venous blood samples for assessment of electrolytes were collected in the following sequence: T1- before anaesthesia induction, T2 - 10 minutes after anaesthesia induction, T3 - 30 minutes of pneumoperitoneum and T4 - at the end of pneumoperitoneum. Statistical analysis revealed AB disturbances associated with general anaesthesia and pneumoperitoneum, manifested with decreased blood pH, whereas blood PvCO2, PO2 and BE were increased. A constant increase of K+ concentration was recorded in all animals during pneumoperitoneum (P<0.05), whereas iMg registered a significant increase only at T3 (P<0.05). Correlations were recorded between blood pH and Na+, iCa, iMg, as well as between Na+ and Cl¯ at different time points during anaesthesia. No correlations were noted between pH and K+ or PvCO2 and K+. In conclusion, electrolyte imbalance represents a possible complication associated with laparoscopic surgery in healthy cats. However, further studies should investigate the causes involved in K+ concentration elevation.

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The Biochemical parameters in venous blood sampling by direct venipuncture and peripheral intravenous catheter

Journal of Contemporary Medical Sciences ◽

10.22317/jcms.v6i5.829 ◽

2020 ◽

Vol 6 (5) ◽

Author(s):

Fatemeh Jaafaraghaei ◽

Monireh Aghajany-Nasab ◽

Mahsa Aghaei ◽

Nazila Javadi pashaki ◽

Ehsan Kazemnejhad Leili

Keyword(s):

Venous Blood ◽

Venous Catheter ◽

Cross Sectional Study ◽

Blood Sampling ◽

Cross Sectional ◽

Sodium Potassium ◽

Blood Samples ◽

Peripheral Venous Catheter ◽

Peripheral Intravenous Catheter ◽

Sodium And Potassium

Objective: The aim of this study was to compare the results of some biochemical values in venous blood samples obtained by direct venipuncture (DV) and peripheral venous catheter (PVC). Methods: In this cross-sectional study, 78 hospitalized patients in different wards of Poor-Sina Medical and Educational Center of Rasht in 2017 were divided into three equal groups, including patients who were treated with normal saline and dextrose saline and those who did not receive this solution. Two separate blood samples were obtained from each patient, one from PVC and the other from DV. The levels of sodium, potassium, creatinine and blood urea nitrogen (BUN) were measured and compared. Results: Difference of PVC with DV in BUN was generally 0.32±3.18 mg/dl; creatinine, sodium and potassium were 0.02±0.12 mg/dl, 1.00±2.49 mEq/L and 0.15±0.48 mEq/L respectively. There were no statistically significant differences between the two methods in relation to BUN and creatinine (P = 0.377 and P = 0.149, respectively), but significant differences in levels of sodium and potassium were observed between the two blood sampling methods (P = 0.001 and P = 0.008, respectively). Conclusion: According to the results of this study and other studies, PVC can be used to measure BUN and creatinine, not so for sodium and potassium. For other parameters, further investigation is needed.

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