Reduction of Blood Loss From Laboratory Testing in
Hospitalized Adult Patients Using Small-Volume
(Pediatric) Tubes
Francisco Sanchez-Giron, MD; Francisco Alvarez-Mora, MD
● Context.—Blood loss from laboratory testing (BLLT) can
be significant in hospitalized patients. It is a common practice to draw full large-volume tubes of blood from adults.
Objective.—To determine whether BLLT occurred when
a small-volume (pediatric) blood collection tube (SVT) was
substituted for each large-volume blood collection tube
and to note whether an adequate sample still was obtained.
Design.—During 2 consecutive weeks, hospital test requisitions were reviewed to collect patient demographics,
tests requested, and number and type of tubes obtained.
The amount of blood collected and BLLT per patient were
calculated. Reduced sample requirements were calculated,
and phlebotomists and ward nurses were required to use
SVTs. After 2 weeks of familiarization, data were collected
as previously described. Laboratory technicians logged
problems related to the use of SVTs.
Results.—Baseline: 227 patients had 664 requisitions,
and median BLLT per patient was 13.5 mL (interquartile
range [IQR], 7.6–27.3 mL). In critical care patients, the
median was 19.9 mL (IQR, 12.0–35.8 mL), and maximum
BLLT was 159.8 mL. Intervention phase: 246 patients had
696 requisitions, median BLLT was 3.7 mL (IQR, 1.2–6.3
mL; P ⬍ .001). In critical care patients, the median was
5.1 mL (IQR, 2.3–10.9 mL), and maximum BLLT was 61.8
mL (P ⬍ .001). All tests requested could be performed using SVTs, and no additional blood collections were required. Use of SVTs reduced overall BLLT per patient by
73% and by 74% in critical care patients.
Conclusions.—By decreasing the size of the blood collection tube for adults, we were able to markedly reduce
BLLT without noting any insufficient specimen volumes.
(Arch Pathol Lab Med. 2008;132:1916–1919)
L
ing may or may not lead to lower hemoglobin concentration, anemia, and increased transfusion requirements.2–4,6
This situation continues to date.7–10 Actual laboratory instruments use small amounts of sample, often in the range
of 3 to 100 ␮L, but it is common practice to draw full
large-volume tubes, regardless of tests requested and
amount of sample required.
Our objective for this study was to reduce BLLT in hospitalized adults using small-volume tubes (SVTs) and to
evaluate its impact in the analytical phase.
aboratory tests increasingly are used for patient care
due to the large number of tests available and the
short turnaround time due to automated laboratory instruments that make them easy to perform, as well as the
need for objective data to support medical decisions. For
many years it has been well known that blood loss from
laboratory testing (BLLT) can be significant in hospitalized
adults. Early studies report an average daily BLLT of 12.4
mL in general wards and 40 to 50 mL per day in intensive
care units.1–3 In a tertiary care teaching hospital, blood
collected was, on average, 45 times the amount necessary
for analysis.4 In addition, a survey of 19 community and
academic hospitals identified that blood collected for laboratory testing in adult patients was 2.5 to 10 times the
amount collected for pediatric patients for the same tests,
despite the fact that laboratories used the same or similar
laboratory instruments.5 Blood loss due to laboratory testAccepted for publication May 20, 2008.
From the Clinical Pathology Laboratory, Medica Sur, Mexico, DF,
Mexico. Dr Sanchez-Giron is currently with the National Institute of
Genomic Medicine, Mexico, DF, Mexico. Dr Alvarez-Mora is currently
with the Blood Bank, National Institute of Neurology and Neurosurgery, Mexico, DF, Mexico.
The authors have no relevant financial interest in the products or
companies described in this article.
Reprints: Francisco Sanchez-Giron, MD, National Institute of Genomic Medicine, Research Direction, Periférico Sur 4124, Torre Zafiro
II Piso 6, Col Ex-Rancho de Anzaldo, Mexico, DF, 011900, Mexico
(e-mail: fsanchezg1204@yahoo.com.mx; fsanchez@inmegen.gob.mx).
1916 Arch Pathol Lab Med—Vol 132, December 2008
MATERIALS AND METHODS
This study was performed in a hospital laboratory in a 120bed private academic general hospital in Mexico City, Mexico.
During 2 consecutive weeks, hospital test requisitions were reviewed in order to collect patient demographics, tests requested,
and number and type of tubes obtained. Emergency department
patients and pediatric patients were excluded. Monovette (Sarstedt, Germany) large-volume tubes were used for adult phlebotomy with the following volumes and additives: 2.7 mL EDTA,
3 mL sodium citrate, and 4.9 mL serum separator, heparin, and
no-additive tubes. The amount of blood collected was calculated
by multiplying the tube capacity by the number of tubes obtained, because the standard phlebotomy practice in our hospital
is to obtain full-volume tubes. Blood loss from laboratory testing
per patient was the sum of all blood collected during the study
period. Instruments used were Gen-S or Max-M (Beckman-Coulter, Fullerton, Calif) for complete blood cell count (CBC); Synchron LX-20, CX-9, or Access (Beckman-Coulter) for chemistry;
Sysmex 1500, Sysmex 1000 (Dade Behring, Marburg, Germany),
or Mini VIDAS (bioMérieux, Hazelwood, Mo) for coagulation;
Reduction of Blood Loss From Laboratory Testing—Sanchez-Giron & Alvarez-Mora
and ADVIA Centaur (Bayer Diagnostics, Tarrytown, NY), Axsym
(Abbott Diagnostics, Abbott Park, Ill), VITROS ECi (Ortho Clinical Diagnostics, Rochester, NY), and Immage (Beckman-Coulter)
for special chemistry, therapeutic drug monitoring, and infectious
disease serology. Blood cultures, send-out tests, and arterial
blood gas analyses were excluded from the protocol.
Small-volume tubes used in the intervention phase were 1.2
mL EDTA, 1.4 mL citrate, 2.6 and 1.1 mL serum separator, 1.1
mL heparin, and no-additive tubes. Each instrument provider
was contacted to assure that instruments could handle both full
and small volumes as primary tubes in the same run. Tube rack
adapters for SVTs and sample probe calibration were needed for
some instruments. A bar code label of the appropriate size for
the SVT was implemented, and a dedicated bar code label printer
for hospital test requisitions was designated. Before beginning
the study, it was experimentally determined that each instrument
could handle the SVT, that the bar code label was properly recognized, and that sampling and testing could be correctly performed (data not shown).
For each single test or combination of tests identified in the
baseline phase, the reduced amount of whole blood, plasma, or
serum sample needed for testing was calculated, as well as the
type and number of tubes needed. Plasma or serum yield was
calculated assuming a hematocrit of 41%. The amount of sample
needed for testing was the sample amount used to perform the
test plus the dead volume (amount of sample needed for an accurate instrument sampling) plus the volume for at least 1 repetition. When multiple tests were done using the same instrument with the same type of sample, only 1 dead volume was
considered. Laboratory phlebotomists and ward nurses were informed of the intended use of SVTs in adult patients and were
trained on the changed sample and tube requirements. They were
given a pocket card with sample amount and type and number
of SVT required for the most frequent tests requested. An inventory of SVTs was delivered to each ward and to the laboratory
hospital phlebotomy team station.
Two weeks were allocated for familiarization with the changed
sample criteria and for reinforcement on the use of SVTs. Data
from hospital test requisitions were collected during the next 2
consecutive weeks as described in the baseline phase.
For statistical analysis, nonparametric descriptive statistics
were used. For statistical differences, Mann-Whitney U test for 2
different samples was used with a significance level of P ⬍ .05.
RESULTS
Baseline results were as follows: 664 hospital test requisitions for 227 patients were received; 125 (55.1%) were
from female patients, and 102 (44.9%) were from male patients; median age was 50 years (interquartile range [IQR],
36–65 years), ranging from 18 to 94 years old. The median
test requisitions per patient was 1 request (IQR, 1–3), ranging from 1 to 19 requisitions. Of all patients, 52.9% had
just 1 request, whereas 6.2% had between 10 and 19 requisitions. There were 345 test requisitions (52%) from critical care units, 32.9% were from the intermediate therapy
unit, 11.6% were from the intensive care unit (ICU), and
7.5% were from the coronary care unit, whereas 48% were
from other hospital services, including different surgical
and internal medicine specialties and subspecialties. The
number of blood tubes collected was 1309 for 5088 ordered tests; 4123 (81.0%) were chemistry tests, 774 (15.2%)
were CBC and coagulation studies, and 191 (3.8%) were
immunology tests. The median number of tests per tube
was 8 for serum separator, 3 for heparin tube, and 1 for
EDTA, citrate, and no-additive tubes. Median BLLT per
patient was 13.5 mL (IQR, 7.6–27.3), ranging from 2.7 to
159.8 mL, whereas in critical care patients the median was
19.9 mL (IQR, 12.0–35.8). Eleven patients (4.8%) had a
BLLT greater than 71.5 mL (95th centile), and 64% of those
Arch Pathol Lab Med—Vol 132, December 2008
patients were in the ICU or intermediate therapy unit. The
highest BLLT (159.8 mL) was in an ICU patient. Total collected blood was 5062.4 mL, and the amount used for testing was 450.8 mL (8.9%), whereas the remaining blood
after testing was 4611.6 mL (91.1%). The most frequent
test requested was CBC (11%), followed by different combinations of CBC, chemistry panel 4 (glucose, blood urea
nitrogen, creatinine, uric acid), serum electrolytes, calcium, phosphorus, and magnesium, which accounted for
23.2% of all tests requested.
During the intervention phase, 696 test requisitions for
246 patients were received: 130 women (52.8%) and 116
men (47.2%) with a median age of 52 years (IQR, 37–68
years; P ⫽ .45) and ranging from 18 to 95 years. The median number of requisitions per patient was 1 requisition
(IQR, 1–3), the same as in the baseline phase; 54.9% of
patients had 1 requisition, whereas 4.5% had 10 to 27 requisitions; 44.2% of requisitions were from critical care
units, 18.7% were from the intermediate therapy unit,
13.4% were from the ICU, and 12.1% were from the coronary care unit. There were 1346 blood tubes collected for
a total of 5165 tests. There was no variation in the type of
tests requested, with 81.2% for chemistry, 15.6% for CBC
and coagulation, and 3.3% for immunology. Median BLLT
per patient greatly decreased to 3.7 mL (IQR, 2.3–7.3 mL),
ranging from 1.1 to 61.9 mL, a reduction of 73% compared
with baseline (P ⬍ .001). Critical care patients had a median BLLT of 5.1 mL (IQR, 2.3–10.9 mL), a reduction of
74% compared with baseline. The highest BLLT was 61.8
mL from a critical care patient. Twelve patients (4.9%) had
a BLLT greater than 25.1 mL (95th centile), and 80% of
those patients were from an ICU or intermediate therapy
unit. Total blood collected was 1715.2 mL (P ⬍ .001), and
the amount used for testing was 447.8 mL (26.1%), which
was not statistically different from baseline (P ⫽ .05). The
remaining blood after testing was 1267.4 mL (73.9%), statistically different from baseline (P ⬍ .001; Table).
For the impact on the analytical phase, all tests requested were performed with the SVTs as primary tubes. It was
not necessary to transfer the sample to sample cups and,
when needed, repeated analysis could also be performed.
There was no need to redraw blood from the patient because of insufficient sample volumes.
COMMENT
Use of SVTs in adults to reduce BLLT was first indicated
18 years ago by Smoller et al,11 who reported a 46.8% reduction of BLLT in 41 ICU patients. In the same year, Foulke and Harlow12 reported a 33% reduction of BLLT using
SVTs, reduced syringe volumes, and reporting patients’
daily BLLT to physicians. Eleven years later, in a survey
of 19 hospitals (7 pediatric hospitals), Hicks5 showed that
it was common practice to draw an excess of blood for
laboratory testing in adult patients compared with the
amount obtained in children’s hospitals. Blood collected
was up to 10 times the volume requested for pediatric
patients, despite the fact that hospitals surveyed used the
same or similar equipment.5 This was further confirmed
in a Q-Probes study by the College of American Pathologists on specimen collection volumes for laboratory tests.
In this study, only 20 (14.4%) of 139 participant laboratories collected smaller volumes of blood for ICU specimens
than for non-ICU specimens.13 Harber et al14 demonstrated
that in Australia and New Zealand no ICUs routinely used
SVTs, and by implementing a highly conservative protocol
Reduction of Blood Loss From Laboratory Testing—Sanchez-Giron & Alvarez-Mora 1917
Comparative Results Summary (Large- and Small-Volume Tubes)*
Baseline:
Large-Volume Tubes
Intervention:
Small-Volume Tubes
Patients, No.
227
Age, median (IQR), y
50 (36–65)
Male/female, No.
125/102
Tubes required, No.
1309
Requisitions, No.
664
Tests, No.
5088
Requisitions per patient, median (IQR)
1 (1–3)
Maximum requisitions/patient, No.
19
Overall BLLT/patient, median (IQR), mL
13.5 (7.6–27.3)
Critical care BLLT/patient, median (IQR), mL
19.9 (12–35.8)
Maximum blood loss, mL
159.8
Total blood collected, mL
5062
Analyzed blood, mL
450
Remaining blood, mL
4612
* IQR indicates interquartile range; BLLT, blood loss from laboratory testing.
246
52 (37–68)
130/116
1346
696
5165
1 (1–3)
27
3.7 (2.3–7.3)
5.1 (2.3–10.9)
61.8
1715
448
1267
that, among other factors, included the use of pediatric
phlebotomy tubes, they were able to reduce the median
BLLT by more than 80% (40 vs 8 mL). There is only 1
descriptive report in Mexico on BLLT in ICU patients,
where a loss of 45 mL per day and a total of 180 mL
during the ICU stay has been reported, but no intervention to reduce the BLLT was done.15
Our study shows that in a general hospital ward, 50%
to 55% of the patients who need laboratory testing had
only 1 request, and 6.2% of patients at baseline had 10 to
19 requests per patient. Also, 4.5% in the intervention
phase had 10 to 27 requests per patient. Using SVTs, the
overall median BLLT in adult hospitalized patients could
be reduced by 73% and by 74% in critical care patients.
Maximum BLLT was reduced from 159.8 mL at baseline
to 61.8 mL in the intervention phase. Patients with the
highest BLLT were in the intermediate and critical care
units. It is important to note that in our study, the BLLT
in the ICU and the coronary care unit is highly underestimated for 2 reasons: the first because BLLT from arterial
blood gas analysis was not included, because this test is
not performed by the clinical laboratory. The second reason is that discarded blood for line flushing was not considered. BLLT from arterial blood gas analysis sampling
comprises 19% to 34% of the total BLLT.7 Blood loss from
flushing varies between 2 and 5 mL, with a median of 2.8
mL per blood draw.13 We can speculate that the real BLLT
in critical care patients would be approximately 50% higher than the actual figure found in our study. However, not
only critically ill patients have significant BLLT, as 20% to
36% of patients with BLLT greater than the 95th centile
were from noncritical wards. The most frequently requested chemistry, hematology, and coagulation tests can be
done in 1.1-, 1.2-, or 1.4-mL tubes, respectively. For chemistry, a 2.6-mL tube was needed only when total iron-binding capacity plus any other analyte was ordered. All other
combinations of chemistry tests could be done with a 1.1mL tube. In hematology, a 2.7-mL tube was needed only
when erythrocyte sedimentation rate together with a CBC
was ordered. In immunology for a single analyte or thyroid profile requisition, a 1.1-mL tube was obtained; for
gynecologic hormones and rheumatoid and TORCH immunoglobulin G and/or immunoglobulin M profiles, a
2.6-mL tube is needed, and a 4.9-mL tube must be obtained only when hepatitis A, B, or C panel or when 2 or
more profiles were ordered.
1918 Arch Pathol Lab Med—Vol 132, December 2008
Mann-Whitney
U Test, P
.45
⬍.001
⬍.001
⬍.001
⬍.001
.05
⬍.001
Although the use of SVTs is a relatively easy way to
reduce BLLT, laboratories willing to use this approach
must confirm that their analytical instruments are able to
handle SVTs as primary tubes. Adapters for tube racks
and sampling probe adjustments may be required. Also,
it must be experimentally determined that the use of SVTs
does not affect the analytical quality of the results. The
use of an appropriately sized bar code label for SVTs is
needed to allow the observation of the sample characteristics and the amount of blood obtained.
The most efficient use of SVTs to reduce BLLT in hospitalized adult patients would be to restrict their routine
use to the critical, coronary care, and intermediate therapy
units and to have a mechanism to identify patients in general wards with a high frequency of test requisitions so
that SVTs could be used instead of large-volume tubes.
Implementation and compliance with such a policy would
be difficult. Other mechanisms to reduce BLLT, such as
reinfusing the blood used for line flushing,13 recording
and reporting to physicians daily, or cumulative BLLT,7,12
may also be considered as a complement to the use of
SVTs. Upon completion of this study, the use of SVTs for
laboratory testing in adult patients is in effect at our hospital.
In summary, use of SVTs in adult patients reduced the
median BLLT by 73%. Patients in critical and intermediate
therapy units have the highest BLLT, which can be reduced by 74%. Most frequently requested tests can be
done by drawing blood in 1.1-, 1.2-, or 1.4-mL tubes. All
specimens collected in an SVT were of sufficient volume
and compatible with our automated instruments.
References
1. Henry ML, Garner WL, Fabri PJ. Iatrogenic anemia. Am J Surg. 1986;151:
362–363.
2. Smoller BR, Kruskall MS. Phlebotomy for diagnostic laboratory tests in
adults. Pattern of use and effect on transfusion requirements. N Engl J Med. 1986;
314:1233–1235.
3. Tarpey J, Lawler PG. Iatrogenic anemia?: a survey of venesection in patients
in the intensive therapy unit. Anaesthesia. 1990;45:396–398.
4. Dale JC, Pruett SK. Phlebotomy—a minimalist approach. Mayo Clin Proc.
1993;68:249–255.
5. Hicks JM. Excessive blood drawing for laboratory tests. N Engl J Med. 1999;
340:1690.
6. Alazia M, Colavolpe JC, Botti G, Corda N, Ramero C, François G. Blood
loss from diagnostic laboratory tests performed in intensive care units: preliminary
study. Ann Fr Anesth Reanim. 1996;15:1004–1007.
7. Wisser D, van Ackern K, Knoll E, Wisser H, Bertsch T. Blood loss from
laboratory tests. Clin Chem. 2003;49:1651–1655.
8. Thavendiranathan P, Bagai A, Ebidia A, Detsky AS, Choudhry NK. Do blood
Reduction of Blood Loss From Laboratory Testing—Sanchez-Giron & Alvarez-Mora
tests cause anemia in hospitalized patients?: the effect of diagnostic phlebotomy
on hemoglobin and hematocrit levels. J Gen Intern Med. 2005;20:520–524.
9. Wong P, Intragumtornchai T. Hospital-acquired anemia. J Med Assoc Thai.
2006;89:63–67.
10. Chant C, Wilson G, Friedrich JO. Anemia, transfusion, and phlebotomy
practices in critically ill patients with prolonged ICU length of stay: a cohort study.
Crit Care. 2006;10:R140.
11. Smoller BR, Kruskall MS, Horowitz GL. Reducing adult phlebotomy blood
loss with the use of pediatric-sized blood collection tubes. Am J Clin Pathol. 1989;
91:701–703.
12. Foulke GE, Harlow DJ. Effective measures for reducing blood loss from
diagnostic laboratory tests in intensive care unit patients. Crit Care Med. 1989;
17:1143–1145.
13. Dale JC, Ruby SG. Specimen collection volumes for laboratory tests. Arch
Pathol Lab Med. 2003;127:162–168.
14. Harber CR, Sosnowski KJ, Hegde RM. Highly conservative phlebotomy in
adult intensive care. A prospective randomized controlled trial. Anaesth Intensive
Care. 2006;34:434–437.
15. Kaneko-Wada FJT, Reyes CEJ, Hernández MF. Loss of blood volume from
routine hematological tests sampling in the Military Central Hospital intensive
care unit patients. Rev Asoc Mex Med Crit Ter Int. 2000;14:5–11.
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