Impact of posture on the "reference range" for serum proteins and calcium.
Author(s): Humphrey KR, Gruemer HD, Lott JA
Publication: Clin Chem, 1977, Vol. 23, Page 1343-6
PubMed ID: 872386 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to determine the effects of patient posture during blood specimen collection on total protein in serum. Total protein was measured in plasma from healthy volunteers. The study commenced with blood drawn from upright (sitting or standing) volunteers at 8:30 am, after which point volunteers maintained a recumbent position for 1 h and then returned to an upright seated or standing position for the second hour. Heparinized plasma total protein levels were converted to serum levels by subtraction of 3 g/L and were retrospectively compared to serum protein levels in a hospital patient population (assumed to be largely drawn in a supine position) and in blood donors.
Summary of Findings:
The median values of the total serum protein (calculated from plasma) in specimens from healthy volunteers in the upright position (standing or seated) and total serum protein in specimens from blood donors were higher than the median value of serum protein in the inpatient population. In the healthy volunteers, corrected total serum protein decreased by an average of 7% after volunteers had been recumbent for 30 minutes compared to their initial upright specimens, and these values were nearer to the values measured in the inpatient population. No further significant decreases in corrected total serum protein were noted after being recumbent for 60 min.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
- Not specified
Platform:
Analyte Technology Platform Protein Colorimetric assay Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Time of biospecimen collection 8:30 am
9:00 am
9:30 am
10:30 am
Biospecimen Aliquots and Components Blood and blood products Plasma
Serum
Biospecimen Acquisition Patient posture Sitting
Standing
Supine
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Study Purpose
The purpose of this study was to determine the effects of patient posture during blood specimen collection on calcium levels in heparinized plasma. The study commenced with blood drawn from upright (sitting or standing) healthy volunteers at 8:30 am, after which point volunteers maintained a recumbent position for 1 h and then returned to an upright position for the second hour. Values were compared retrospectively to values measured in a hospital patient population (assumed to be largely drawn in a supine position) and a normal reference group of blood donors.
Summary of Findings:
The median values of plasma calcium for healthy volunteers in the upright position and normal reference blood donors were higher than the median value of calcium in the inpatient population. In the healthy volunteers, plasma calcium decreased by an average of 2% (p<0.01) after volunteers had been recumbent for 30 minutes compared to the levels in the initial upright specimens, and these values were nearer to the values measured in the inpatient population. No further significant decreases in calcium were noted after being recumbent for 60 min.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
- Not specified
Platform:
Analyte Technology Platform Electrolyte/Metal Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Time of biospecimen collection 8:30 am
9:00 am
9:30 am
10:30 am
Biospecimen Acquisition Patient posture Sitting
Standing
Supine