Laboratory Test Reference Range Lower Limit Standard Unit

SummaryAge-related trends in serum free thyroxine (FT4) and free triiodothyronine (FT3) concentrations were measured in 7248 euthyroid subjects (age-range 3 months to 106 years). 5700 were patients referred to hospitals for investigation of suspected thyroid dysfunction, but who were diagnosed euthyroid. 1548 were healthy blood donors (age-range 18-63 years) with no indication of thyroid dysfunction. FT4 concentrations were little affected by the age, the sex or the state of health of the subjects in either group. Serum FT3 concentrations were significantly affected by both age and health factors. The upper limit of the euthyroid reference range for young subjects up to 15 years was about 20% higher (10.4 pmol/1) than for adult subjects older than 25 years (8.8 pmol/1). The change in the upper limits typical of young subjects to that typical of adults occurred steadily over the decade 15–25 years. After this age, little further change occurred, especially in healthy subjects. Additionally, the lower limit of the euthyroid range for FT3 was extended by the inclusion in the reference group of patients referred to hospitals. Compared with the lower limit of the FT3 range for healthy subjects (5 pmol/1), the corresponding limit for referred subjects (young or adult) was 3.5–3.8 pmol/1. Broadening of the FT3 reference range was probably brought about by a significant number of patients in the hospital-referred group with the “1OW-T3 syndrome” of mild non-thyroidal illness. Accordingly, FT3 was inferior to FT4 in the discrimination of hypothyroidism, as FT4 was unaffected by this phenomenon. Effects of age and non-thyroidal illness on serum FT3 concentrations require great care when selecting subjects for a laboratory euthyroid reference range typical of the routine workload. Constraints on the choice of subjects for FT4 reference ranges are less stringent.

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Physical health examination in outpatients with schizophrenia: the cost effectiveness of laboratory screening tests

Annals of General Psychiatry ◽

10.1186/s12991-020-00321-3 ◽

2020 ◽

Vol 19 (1) ◽

Author(s):

Saana Eskelinen ◽

Janne V. J. Suvisaari ◽

Jaana M. Suvisaari

Keyword(s):

Cost Effectiveness ◽

Laboratory Test ◽

Reference Range ◽

Health Examination ◽

Abnormal Result ◽

Gamma Glutamyltransferase ◽

Hydroxyvitamin D ◽

Laboratory Screening ◽

25 Hydroxyvitamin D ◽

The Cost

Abstract Background Guidelines on laboratory screening in schizophrenia recommend annual monitoring of fasting lipids and glucose. The utility and the cost effectiveness of more extensive laboratory screening have not been studied. Methods The Living Conditions and the Physical Health of Outpatients with Schizophrenia Study provided a comprehensive health examination, including a laboratory test panel for 275 participants. We calculated the prevalence of the results outside the reference range for each laboratory test, and estimated the cost effectiveness to find an aberrant test result using the number needed to screen to find one abnormal result (NNSAR) and the direct cost spent to find one abnormal result (DCSAR, NNSAR x direct cost per test) formulas. In addition, we studied whether patients who were obese or used clozapine had more often abnormal results. Results A half of the sample had 25-hydroxyvitamin D below, and almost one-fourth cholesterol, triglycerides or glucose above the reference range. One-fifth had sodium below and gamma glutamyltransferase above the reference range. NNSAR was highest for potassium (137) and lowest for 25-hydroxyvitamin D (2). DCSAR was below 5€ for glucose, all lipids and sodium, and below 10€ for creatinine and gamma glutamyltransferase. Potassium (130€), pH-adjusted ionized calcium (33 €) and thyroid stimulating hormone (33€) had highest DCSARs. Several abnormal results were more common in obese and clozapine using patients. Conclusions An annual laboratory screening panel for an outpatient with schizophrenia should include fasting glucose, lipids, sodium, creatinine, a liver function test and complete blood count, and preferably 25-hydroxyvitamin D.

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A Modification of the Standard Weather Bureau Rain Gage for Summer and Winter Use 1

Bulletin of the American Meteorological Society ◽

10.1175/1520-0477-42.5.311 ◽

1961 ◽

Vol 42 (5) ◽

pp. 311-313

Author(s):

F. B. Gomm

Keyword(s):

Laboratory Test ◽

Field Tests ◽

Rubber Stopper ◽

Standard Unit ◽

Weather Bureau ◽

Rain Gage ◽

Collection Tube ◽

Standard Collection ◽

Measuring Tube ◽

Vent Tube

This article describes a modified collection unit for the standard Weather Bureau-type rain gage. The described unit, consisting of a polyethylene bottle, rubber stopper, vent tube and adapter funnel, replaces the metal collection tube of the standard gage. In a laboratory test, evaporation from the modified system was not great enough in a 30-day period to measure with a standard measuring tube. Field tests showed the described unit superior to the standard collection unit and equal to the standard unit with a 0.20-inch oil film in the reduction of evaporation. The described unit, which eliminates recharging with oil or antifreeze after each reading, has been in field use for two years without damage from freezing.

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SAT-047 Adoption of an Age Adjusted Testosterone Reference Range Reduces Referrals to Endocrine Clinic and New Prescriptions of Testosterone

Journal of the Endocrine Society ◽

10.1210/jendso/bvaa046.817 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

Author(s):

Charlotte Dewdney ◽

Heidi Mendoza ◽

Rosemary Clark ◽

Sandra MacRury ◽

Rod Harvey ◽

...

Keyword(s):

Lower Limit ◽

Reference Range ◽

Age Groups ◽

Male Hypogonadism ◽

Reference Ranges ◽

Endocrine Society ◽

Testosterone Levels ◽

Referral Criteria ◽

Before And After ◽

The Impact

Abstract Testosterone levels decline with age. However, until recently well defined harmonised age and/or obesity (BMI <30kg/m2) adjusted reference ranges did not exist.1 There is also a lack of international consensus on whether an age adjusted reference range (RR) should be used to define the syndrome of hypogonadism in men. Our local referral guideline suggests referral to endocrinology is appropriate if morning testosterone is <9.4nmol/L similar to the Endocrine Society Clinical Practice Guideline.2 In mid 2018 our laboratory adopted the published all men age adjusted RR1. We sought to; i) investigate clinic referrals before and after adoption of the all men age adjusted RR and, ii) to model the impact on referrals and prescription of testosterone replacement therapy (TRT) had we adopted either the lower limit of either all men or non-obese age adjusted RR as our referral criteria. Despite similar numbers of testosterone levels being measured in the laboratory, referrals to endocrine clinic for investigation of male hypogonadism fell by 52% (n=101 vs 48) in the one year following the introduction of the new age adjusted RR, with a corresponding reduction in prescriptions for testosterone. Mean testosterone concentration (6.7±2.5 vs 6.4±3.9nmol/L [mean±SD], NS), and age (51±13.9 vs 50±17.9 years, NS) of individuals referred were similar before and after the change of RR. Of the 101 patients referred for investigation of hypogonadism prior to the new RR mean testosterone concentrations were 8.5±4.5, 7.3±4.1, 6.8±3.6, 6.7±2.1 & 6.6±1.6nmol/L, with 39, 71, 39, 40 & 17% of the 87 patients seen in clinic being prescribed TRT in age groups 19-39 (n=28), 40-49 (n=7), 50-59 (n=33), 60-69 (n=20) &70-79 (n=6) respectively, excluding those with a history of anabolic steroid use or Klinefelter’s syndrome. Mean BMI was 30.9±4.4kg/m2, which was similar between age groups. Had the lower limit of normal of the all men testosterone RR been employed as our referral criteria in the preceding year, 23.8% (24/101) of referrals would not have met referral criteria, and 26.2% (n=11/42) of those receiving a prescription would potentially not have received a trial of TRT. In contrast, had the non-obese age adjusted RR had been adopted for all men 13.9% (14/101) of referrals would not have met referral criteria and, of those prescribed testosterone, 2.4% (n= 1/42) would not have received a trial of TRT. In conclusion, adoption of the all men age adjusted RR for testosterone has been associated with a significant fall in referrals for investigation of male hypogonadism. However, modelling of historical clinic data would suggest that some non-obese individuals miss out on a therapeutic trial of TRT, especially if the all men, rather than non-obese, age adjusted RR is adopted. Reference: (1) Travison et al, J Clin Endocrinol Metab, 2017,102(4):1161-1173, (2) Bhasin S et al,. J Clin Endocrinol Metab. March 2018;103(5):1715-1744.

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What is the normal range of obstetric shock index in the immediate postpartum period in a low resource setting?

10.21203/rs.3.rs-24593/v1 ◽

2020 ◽

Author(s):

Johnbosco Ifunanya Nwafor ◽

Chuka Nobert Obi ◽

Olisah Elvis Onuorah ◽

Blessing Idzuinya Onwe ◽

Chukwunenye Chukwu Ibo ◽

...

Keyword(s):

Lower Limit ◽

Current Literature ◽

Reference Range ◽

Vital Signs ◽

Shock Index ◽

Normal Range ◽

Upper Limit ◽

Resource Setting ◽

Haemodynamic Changes ◽

Obstetric Population

Abstract AbstractObjective: To determine the normal range of shock index (SI), blood pressure (BP), mean arterial pressure (MAP) and heart rate (HR) among postpartum women and to compare shock index with the normal range in the current literature.Methods: This is a prospective cohort study evaluating vital signs collected at one hour of delivery in women with normal blood loss delivered in Abakaliki, Nigeria. Results: The median (95% reference range) was 120 (100 - 155.8) for systolic BP, 70 (60 - 94) for diastolic BP, 90 (66.5 - 116.6) for MAP, 82 (65 - 102) for HR, and 0.69 (0.48 - 0.89) for SI. The upper limit of SI of 0.89 in this study did support the current literature suggesting a threshold of 0.9 as upper limit of normal. However, the lower limit of SI of 0.48 in this study corresponds to the lower limit of 0.5 for non-obstetric population. Over half (56%) of the study cohorts maintained shock index values within the normal range (0.5 - 0.7) for non-obstetric population. Conclusion: Although haemodynamic changes of pregnancy widens the range of shock index in obstetric population, 56% of the participants maintained normal shock index within the reference range for non-obstetric population. We recommend that the normal obstetric shock index range of 0.7 - 0.9 in current literature be changed to 0.5 - 0.9 to accommodate this lower threshold.

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The dynamics of immunological parameters in early stages after bilateral lung transplantation in patients with various pulmonary pathology

Transplantologiya The Russian Journal of Transplantation ◽

10.23873/2074-0506-2018-10-4-274-283 ◽

2018 ◽

Vol 10 (4) ◽

pp. 274-283

Author(s):

M. Sh. Khubutiya ◽

E. A. Tarabrin ◽

E. I. Pervakova ◽

V. P. Nikulina ◽

M. A. Godkov

Keyword(s):

Cystic Fibrosis ◽

Lung Transplantation ◽

Lower Limit ◽

T Lymphocyte ◽

Lymphocyte Count ◽

Lung Diseases ◽

Lung Transplant ◽

Reference Range ◽

Group 2 ◽

Group 1

Background. The diseases leading to the need for lung transplantation include chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, alpha-1-antitrypsin deficiency, idiopathic pulmonary hypertension, histiocytosis X, and sarcoidosis. Primary lung transplant dysfunction is a frequent complication after transplantation and represents a multifactorial injury of the transplanted lung, its pathogenesis being associated with a severe hypoxemia of the lung transplant and diffused damage to the alveoli. The clinical presentation is in many ways similar to an acute respiratory distress syndrome, which pathogenesis is primarily effected by the activation of immune system cells. The cytokine production by immunocompetent cells, the synthesis of reactive oxygen and nitrous oxide, being the mediators of inflammation, trigger inflammatory processes in the lungs; the immunoglobulin synthesis derangements also lead to the development of inflammatory abnormalities in the lungs and a poor transplantation outcome.The objective was to study the immunological response in the lung transplant recipients suffering from the underlying disease of various etiology and to determine the immunological predictors of adverse outcome in the early period after bilateral lung transplantation.Material and methods. Twenty nine patients were examined within 2 weeks after lung transplantation: Group 1 comprised 10 patients with cystic fibrosis (6 women, 4 men) aged 27.8 ± 2.7 years; Group 2 included 19 patients (7 women, 12 men) at the age of 38.5 ± 10.4 years having other lung diseases. Mortality was 10% (1 patient) in Group 1, and 52.5% (10 patients) in Group 2. The patients were followed-up according to the standard protocol of postoperative treatment and immunosuppression therapy shemes. Immunological monitoring included the lymphocyte phenotyping, and the assessment of phagocytic activity of neutrophils, the HCT-test, the blood levels of immunoglobulins (Ig) A, M, G, circulating immune complexes, and C-reactive protein. Statistical significance was assessed at p <0.05.Results. On day 5, the T-lymphocyte count in patients of Group 1 was 674 cells/μL (Me), which was 26.7% lower than lower limit of the reference range, but 2.5 times higher than that in patients of Group 2 (266 cells/μL). The number of T-lymphocytes in patients of the 2nd group was recorded at 71.1% below the lower limit of the reference interval (p < 0.05). The blood level of IgA (Me) in patients of Group 1 was within the normal range (Ме– 1.9 g/L), the blood level of IgA (Me) in patients of Group 2 was 1.4 g/L, which was 26.3% lower than below the lower limit of the reference values and lower than in Group 1 (p < 0.05).By day 13, the count of T-lymphocytes in Group 1 had increased 2.2 times compared to day 5, reaching the reference values (Me), and made 1479 cells/μL. In the 2nd group, there was a 1.5-fold increase in T-lymphocyte count (Me 408 cells/μL), which was 3.7 times lower than the lower limit of the reference range and lower than in the 1st group (p < 0.05). The level of IgA in patients of the 1st group increased by 20.8% and amounted to 2.4 g/L (Me), and in patients of the 2nd group, the level of IgA for 2 weeks remained almost unchanged (Me 1.5 g/L ) and was 1.7 times lower than in the 1st group (p < 0.05).Conclusions. On day 5 after transplantation, the patients with cystic fibrosis demonstrated the increase in the T-lymphocyte count and IgA level by 2.5 and 1.4 times, respectively, compared to the patients with other lung diseases. By the end of week 2, T-lymphocyte and IgA values in patients with cystic fibrosis, unlike patients with other lung diseases, had reached the reference range. The T-lymphocyte count and the concentration of IgA below the reference range in the first 2 weeks after lung transplantation were the immunological predictors of adverse outcome.

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The APTTCan Monitor for Increased Thrombotic Risk.

Blood ◽

10.1182/blood.v104.11.3508.3508 ◽

2004 ◽

Vol 104 (11) ◽

pp. 3508-3508

Author(s):

Sarah Mengshol ◽

Jerry B. Lefkowitz

Keyword(s):

Lower Limit ◽

Reference Range ◽

Clinical Laboratory ◽

Coagulation Factor ◽

Factor Ix ◽

Activity Level ◽

Reference Ranges ◽

Thrombotic Risk ◽

Normal Plasma ◽

Increased Risk

Abstract This laboratory has been interested in the significance of short activated partial thromboplastin times (APTT) and has published work suggesting that short APTTs are associated with an increased thrombotic risk (Am J Clin Path113:123–127, 2000). Since our original publication, other workers have shown that increased levels of coagulation factor II (FII), factor VIII (FVIII), factor IX (FIX), or factor XI (FXI) are associated with an increased risk of thrombosis. Therefore, this study was designed to determine if elevated levels of FII, FVIII, FIX, or FXI might predictably result in a shortened APTT. Using a set of 30 normal plasma samples, APTT reference ranges were determined on a Stago ST4 analyzer for the following APTT reagents--Stago PTTA5, Dade Behring Actin FSL, Hemosil Synthasil, and Biomèrieux Platelin L. For this study, a short APTT was defined as being below the value of the reference range lower limit. FII, FVIII, FIX, and FXI levels were determined on a pool normal plasma in the clinical laboratory and these levels were used as a baseline to add purified factor to increase a factor activity level. The amount of factor level increase was based upon literature reports of factor levels associated with an increased thrombotic risk. A normal baseline APTT control was run for each set of assays. The coefficient of variation for control APTTs ranged from 1%–3.4% and seemed to be dependent on the specific APTT reagent. Differences were noted in the sensitivity between different APTT reagents to elevated factor levels, but all APTT reagents demonstrated the same overall trend to higher factor levels. In addition to raising individual factor concentrations, several plasmas were spiked with combinations of FVIII and FIX or FVIII, FIX, and FXI. Increasing concentrations of FVIII showed a significant decrease in the APTT, up to 3.5 seconds below the lower limit reference range at 2.2 units (U)/mL. Increasing [FIX] was associated with a trend towards a shorter APTT, but no decrease below the lower limit APTT reference range was found even with a [FIX] of 1.8 U/mL. When compared to control APTTs, increases in [FXI]<1.2 U/mL were associated with a shortening of the APTT but with [FXI]>1.4 U/ml the APTT prolonged compared to control. In no case did increases in FXI level cause the APTT to be outside of the reference range. Increasing concentrations of FII were associated with prolongations of the APTT compared to control. At the highest [FII] of 1.9 U/mL 3 of the 4 APTT reagents gave results up to 1.4 seconds above the upper limit of the reference range. When both [FVIII] and [FIX] were increased, minimal difference was seen in the APTT compared to only increased [FVIII]; however, when the concentrations of FVIII, FIX, and FXI were increased, the APTT was shortened up to 5.7 sec below the lower APTT reference range when compared to samples which had only a single factor concentration raised. These data show an association with increasing [FVIII] in plasma and shortening of the APTT. They also show that increased [FVIII] in combination with elevated levels of FIX and FXI cause a significant shortening of the APTT that exceeds a simple additive effect. These findings suggest that the APTT could be used as a screening test for elevated plasma coagulation factors, especially elevated [FVIII] which has been previously associated with an increased risk of thrombosis.

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