Our principal aim is to assess the effects of phlebotomy on aortic augmentation (AIx) and central BP in supine position and after standing; second, to assess the effects of counter maneuvers (leg crossing and thigh compression) on aortic…
ID
Source
Brief title
Condition
- Red blood cell disorders
- Hepatic and hepatobiliary disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
- Significant difference in aortic augmentation as well as difference in
central BP of * 10 mmHg systolic or * 5 mmHg diastolic before and after
phlebotomy in supine and standing position with or without counter maneuvers.-
- Difference in aortic augmentation of * 4% as well as difference in central BP
of * 10 mmHg systolic or * 5 mmHg diastolic after phlebotomy in patients with
or without saline infusion (viscosity changed/unchanged).
Secondary outcome
To assess the effects of phlebotomy on cardiac output and peripheral resistance
while supine and after standing
To assess the effects of phlebotomy on forward and backward waves in supine
position and after standing
To assess the effects of phlebotomy with saline repletion on cardiac output and
peripheral resistance while supine and after standing
To assess the effects of phlebotomy with saline repletion on forward and
backward waves in supine position and after standing
Background summary
Recently it has been demonstrated that upon standing wave reflection and
central blood pressure (BP) decrease despite an increase in systemic vascular
resistance. The decrease in central aortic augmentation and central BP can be
attenuated by unilateral leg compression. This suggests that aortic
augmentation (AIx) and central BP are sensitive to alterations in venous
return. Our principal aim is to assess whether changes in volume status affect
aortic augmentation (AIx) and central BP in patients receiving regular
phlebotomy while supine and after standing. Because changes in blood viscosity
may influence AIx, BP and cardiac output,the current study also aims to assess
the difference of BP and AIx in patient who receive volume replacement after
phlebotomy
Study objective
Our principal aim is to assess the effects of phlebotomy on aortic
augmentation (AIx) and central BP in supine position and after standing;
second, to assess the effects of counter maneuvers (leg crossing and thigh
compression) on aortic augmentation (AIx) and central BP before and after
phlebotomy while standing and third, the difference between viscosity change
and volume depletion on aortic augmentation (AIx) and central BP.
Study design
Experiment with non-invasive measurements of hemodynamics before and after
phlebotomy. Each subject serves as his or her own control.
Study burden and risks
We aim to objectify the difference in BP and AIx after phlebotomy to better
comprehend in what way phlebobtomy affects BP and central hemodynamics. The
burden of this study consists of one visit, with a duration of approximately
one hour. The techniques used are the Nexfin, the Arteriograph and the
MicroScan Video Microscope which will measure central BP, MAP, AIx, stroke
volume, heart rate, systemic vascular resistance, forward and backward waves,
cardiac output, pulse pressure, baroreflex and objectify microcirculation in
supine and standing position with and without counter maneuvers before and
after phlebotomy. Furthermore a short questionnaire will be taken to assess
record patients* age, gender, medical history, demographic variables,
medication use and co-morbidity. Also length, weight and waist circumference
will be measured. Finally a blood sample will be taken during and after the
phlebotomy for hemoglobin, plasma viscosity and hematocrit.
Meibergdreef 9
Amsterdam 1105AZ
NL
Meibergdreef 9
Amsterdam 1105AZ
NL
Listed location countries
Age
Inclusion criteria
Without volume replacement:
- Patients aged 18-75 years receiving phlebotomy at regular intervals (for example because of hemochromatosis, porphyria and polycythemia vera)
- Known to tolerate phlebotomy
- Willing to participate
- Able to provide informed consent.
Patients which are known to tolerate phlebotomy without any adverse events are included in the *no-volume replacement group.* Patients who have experienced adverse events after phlebotomy in the past, and are previously assigned to receive volume replacement by their attending physician, are included in the *volume replacement group.* We aim to include the same amount of patients in each group.
Exclusion criteria
- Pacemaker or ICD device
- Atrial fibrillation
- Mechanical heart valve
- Congestive heart failure (*NYHA III/IV)
- Unable to stand up
- Uncontrolled hypertension (BP>180/110 mmHg)
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL44193.018.13 |