.

1. Are individuals presenting
with hypotension eligible
as whole blood donors?
A systematic review
Nele Pauwels
Centre for Evidence-Based Practice

2. Introduction
 Donor selection prior to donation to protect the
health of donor and recipient
− E.g. blood pressure measurement
 No uniform donor selection criteria
− E.g. hemochromatosis patients
− E.g. individuals presenting with hypotension
 Belgian Red Cross-Flanders: donor
management based on the best available
scientific evidence
Pauwels NS, De Buck E, Compernolle V, Vandekerckhove P. Worldwide policies on haemochromatosis
and blood donation: a survey among blood services. Vox Sang. 2013, 105(2):121-128.

3.  How to collect the evidence behind our donor
health decisions?
Introduction
Systematic review
Methodology according to The Cochrane Collaboration
De Buck E, Pauwels NS, Dieltjens T, Vandekerckhove P. Use of evidence-based practice in an aid
organisation: a proposal to deal with the variety in terminology and methodology. Int J Evid Based Healthc.
2014, 12(1):39-49.

4. Systematic review
1. Formulation of the research question
2. Development of the search strategy and search in
multiple databases
3. Evidence selection
4. Extraction and synthesis of the data
5. Quality assessment of the included studies and
assignment of the levels of evidence (i.e.
determination of bias, using the GRADE approach)

5. 1. Research question
 In blood donors presenting for whole blood
donation, does hypotension increase the risk of
donor adverse events when compared with
normotension?

6. 2. Search strategy
 Systematic search in 5 databases
− from inception date until 12th April 2013

7. 2. Search strategy
 Systematic search in 5 databases
− using highly sensitive search strings
(“Blood Donors”[Mesh] OR blood don*[TIAB] OR “Blood Banks”[Mesh] OR blood bank*[TIAB] OR blood
centre*[TIAB] OR blood center*[TIAB] OR blood service*[TIAB]) AND (“Hypotension”[Mesh:NoExp] OR
hypotens*[TIAB] OR “Arterial Pressure”[Mesh] OR “blood pressure”[TIAB] OR “systolic pressure”[TIAB] OR
“diastolic pressure”[TIAB] OR “Risk”[Mesh:NoExp] OR “Risk Factors"[Mesh] OR risk factor*[TIAB] OR “Risk
Assessment”[Mesh:NoExp] OR “predonation”[TIAB] or “pre donation”[TIAB] OR “predictive”[TIAB] OR
deferral*[TIAB] OR referral*[TIAB] OR inclusion*[TIAB] OR exclusion*[TIAB] OR “retention”[TIAB] OR
retain*[TIAB] OR return*[TIAB] OR “first time”[TIAB] OR “Blood Volume”[Mesh:NoExp] OR “blood
volume”[TIAB] OR “donor selection”[Mesh] OR “donation history”[TIAB] OR “donation status”[TIAB] OR “body
weight”[Mesh:NoExp] OR “weight”[TIAB] OR “body mass index”[Mesh] OR “body mass index”[TIAB] OR
“BMI”[TIAB]) AND (“Syncope”[Mesh] OR syncop*[TIAB] OR “vasovagal”[TIAB] OR “vaso vagal”[TIAB] OR
“Unconsciousness”[Mesh:NoExp] OR unconscious*[TIAB] OR conscious*[TIAB] OR “Hypotension,
Orthostatic”[Mesh] OR collaps*[TIAB] OR faint*[TIAB] OR convuls*[TIAB] OR "Bradycardia"[Mesh] OR
“bradycardia”[TIAB] OR “Urinary Incontinence”[Mesh:NoExp] OR “Fecal Incontinence”[Mesh] OR
“incontinence”[TIAB] OR “Sweating”[Mesh] OR “diaphoresis”[TIAB] OR “diaphoretic”[TIAB] OR “sweat”[TIAB]
OR “sweaty”[TIAB] OR “sweating”[TIAB] OR “Dizziness”[Mesh] OR “dizzy”[TIAB] OR “dizziness”[TIAB] OR “light
headedness”[TIAB] OR “lightheadedness”[TIAB] OR “Nausea”[Mesh:NoExp] OR “nausea”[TIAB] OR
“nauseous”[TIAB] OR “vomit”[TIAB] OR “vomiting”[TIAB] OR “vomited”[TIAB] OR “weak”[TIAB] OR
“weakened”[TIAB] OR “weakness”[TIAB] OR “Pallor”[Mesh] OR “pallor”[TIAB] OR “veins/injuries”[Mesh:NoExp]
OR “Hematoma”[Mesh:NoExp] OR “hematoma”[TIAB] OR “haematoma”[TIAB] OR “Ecchymosis”[Mesh] OR
“ecchymosis”[TIAB] OR “ecchymoses”[TIAB] OR “Contusions”[Mesh] OR “contusion”[TIAB] OR
“contusions”[TIAB] OR “bruise”[TIAB] OR “bruises”[TIAB] OR “bruising”[TIAB] OR “nerve”[TIAB] OR side
effect*[TIAB] OR “adverse”[TIAB] OR reaction*[TIAB] OR complication*[TIAB] OR “incident”[TIAB] OR
“incidents”[TIAB] OR “safe”[TIAB] OR “safety”[TIAB])

8. 3. Evidence selection
8305 potentially relevant records
53 records
(i.e. 45 peer-reviewed
publications and
9 conference
abstracts)
5418 records
(including peer-reviewed publications and
conference abstracts)
Screening based on title and
abstract evaluation
5365 irrelevant records excluded
Full text evaluation
Screening of reference list of
included records
Reviewer 1
102 articles
Reviewer 2
identified:
CENTRAL (n= 93), MEDLINE (n= 1838),
Embase (n= 3757), CINAHL (n= 205)
Web Of Science (n= 2412)
8 records
selected
(i.e. 7 peer-reviewed
publications and
1 conference
abstract)
9 records included in systematic
review
(8 peer-reviewed publications and 1 conference
abstract including 10 observational studies in total)
Duplicate removal
2887 duplicates removed
Screening based on title and
abstract evaluation
5379 irrelevant records excluded
Full text evaluation
Screening of reference list of
included records
39 records
(i.e. 30 peer-reviewed
publications and
10 conference
abstracts)
8 records
selected
(i.e. 7 peer-reviewed
publications and
1 conference
abstract)

9. 4. Extract and synthesize data

10. 4. Extract and synthesise data
 Out of 8305 records, 10 observational studies
were identified that addressed the question
 Five of these studies (with a combined total of
1,482,020 donations and 2903 donors) included
either a statistical analysis or an appropriate study
design that controlled for possible confounding
factors
 Based on the currently available evidence,
hypotension has not been shown to be an
independent predictive factor for donor
complications.

11. 5. Quality assessment
 Overall quality of body of evidence
INITIAL QUALITY LEVEL
RELATED TO STUDY DESIGN
LOW
Limitations of study design No major limitations
Imprecision No
Inconsistency No
Indirectness No
Publication bias No
QUALITY (GRADE) LOW
− ‘Low quality’ = further research is very likely to have
an important impact on our confidence in the
estimate of effect and is likely to change the estimate
www.gradeworkinggroup.org

12. Publication

13. From evidence to recommendation:
the Evidence-Based Practice approach

14. From evidence to recommendation:
the Evidence-Based Practice approach
 Discussion with team of experts and representatives of the
target group

15. Thank you
Contact:
Nele.Pauwels@rodekruis.be
Cebap@rodekruis.be