effects of shed mediastinal blood on cardiovascular and pulmonary function: a randomized and double...
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Effects of Shed Mediastinal Blood on Cardiovascular and Pulmonary Function:
A Randomized and Double Blind Study
Effects of Shed Mediastinal Blood on Cardiovascular and Pulmonary Function:
A Randomized and Double Blind Study
Presented by: Maggie SavelbergOn: February 18, 2009
Presented by: Maggie SavelbergOn: February 18, 2009
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3
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1Problem: Suction Blood Good?
Objective & Methods
Results & Future Implications
Limitations of Paper
Overview:Overview:
Identification of a Problem I:Identification of a Problem I:
Recirculation and retransfusion of shed mediastinal and pericardial blood (since 1978)has been associated with decreased homeostasis and increased morbidity
Principle Findings (1995) : - ↑ thombin-antithrombin III levels - significant ↓ in post-op blood - ↑ tissue-type plasminogen activator loss (p<0.005) - ↑ fibrin degradation products - ↓ blood product use - ↑ free plasma hemoglobin
Retransfusion of sucker blood = ↑ wound bleeding
Ann Thorac Surg 1995;59:901-907
Identification of a Problem II:Identification of a Problem II:
Perfusion 2000;15:427-431
Principle Findings (2000) : - ↑ endotoxin in pooled pericardial blood (p<0.05)
- proposed reinfusion as a possible contributor to overall SIR
- ↑[endotoxin] = respiratory failure, renal failure, bleeding disorders, and neurological dysfunction.
Identification of a Problem IV:Identification of a Problem IV:
Annals of Thoracic Surgery 2004;78:54-59
Principle Findings (2004) : - significant ↑ TNF-α , IL-6, C3a in
retransfusion group (p<0.001)
- ↑ volume retransfusion blood = ↑ TNF-α levels = ↓ Hgb post-operatively
Identification of a Problem III:Identification of a Problem III:
Interactive Cardiovascular and Thoracic Surgery 2009;
Principle Findings (2008) : - lipid-microemboli size ranged from 10- 60µm which have been linked to poor
neurological outcome following CPB. - ↑ concentration following cannulation
and in shed blood from the pleura
- Found in arterial side of HLM circuit
↑ lipid microemboli in pericardial sucker blood bleeding = link to ↓ neurological outcome
I. Objective:I. Objective:
Determine within subset of Cardiotomy Trial patients the effects of cardiotomy blood processing on identified endpoints;
a) cardiovascular function b) pulmonary mechanics c) gas exchange
Annals of Thoracic Surgery 2008;86:1167-74
Clinical identifiers of patient status/health
II. Methods:II. Methods: Study Design
Patient Population:
- 266 patients - non-emergent CABG and/or AV replacement - on-pump CPB - exclusions: neurological deficits
pre-op coagulopathybleeding diathesisthrombocytopeniarenal insufficiencyhepatic insufficiency
- Control: received unprocessed shed mediastinal blood.
- Treatment: received processed shed mediastinal blood.
266 patients
136 133
77
Control Treatment
77
Additional Testing
II. Methods:II. Methods: Study Design
Randomization:
- computer generated randomization
- allocation presented in sealed envelope to perfusionist by research coordinator just prior to giving heparin before CPB.
- all members of the surgical team were unaware due to positioning of opaque drape
- intraoperative decisions to transfuse blood products were made by anesthesia who again, were unaware of treatment assignment.
II. Methods:II. Methods: Intraoperative Protocol Intraoperative Protocol
Interventional Plan:
CPB Strategy: - narcotic based anesthetic - heparin for ACT >400 sec - CPB (roller pump, 43µm art filter closed venous reservoir) - prime (1,300mL) RL solution - bypass flows maintained at 2.4 – 3.2 L/min/m2
- antegrade cardioplegia & topical cooling - body temperature 34ºC, re-warmed to 37ºC
Sucker blood↓
Cell Saver↓
LD Filter↓
Circuit↓
Patient
Study Interventions:
Treatment
Sucker blood↓
Circuit↓
Patient
Control
Baseline / Intraoperative characteristics similar
Cardiotomy blood volumecollected similar in both
groups (p= 0.21)
Patient
Population
III. ResultsIII. Results: A Summary: A Summary
Analyzed before, during and after CPB
No difference in indices of mechanical pulmonary function or
gas exchange b/t groups.
Pulmonary
Function
III. ResultsIII. Results: A Summary: A Summary
Variables Measured
Tidal Volume
Peak Inspiratory Pressure
Positive End Expiratory Pressure
Compliance
** Arterial pO2
** Pulmonary Shunt (Qs/Qt %)
** DO2 index
** Oxygen Extraction Ratio (%)
** Alveolar-arterial oxygen gradient
Impairments in red starred ** variables
(same in both the control and treatment groups)
Cardiovascular
Effects
III. ResultsIII. Results: A Summary: A Summary
↓ PVR + SVR
↑ Cardiac Index (p = 0.004)
↓ duration myocardial
Ischemia(p =0.02)
↑ hgb levels(p=0.003)
being in processed group
Processed
Sucker
Blood
Processed
● Unprocessed
multivariateanalysis revealedonly independent pre/intra operative
factors attributedto improved post-op
cardiac index.
↑ Unprocessed sucker volume = ↓ cardiac hemodynamics
Clinical
Outcomes
ResultsResults: A Summary: A Summary
No ∆ in mortality
↑ creatine kinase in unprocessed group BUTtroponin levels similar
ProcessedUnprocessed P-value
Conclusion: Conclusion: & Future Implications& Future Implications
Principle Findings :
- Processing (centrifugal washing & leukocyte depleting filtration) of cardiotomy blood
= no effect on mechanical pulmonary function = no effect on indices of pulmonary gas exchange
- However, significant hemodynamic changes were observed as a result of cardiotomy blood processing.
= ↓ PVR and SVR (approximately by 30%)= ↑ CI= trend toward ↓ ventilation time
- Individualized Perfusion: (tailored approach) Benefits may to process suctioned blood in patients with poor LV vs.
those with good LV function who are high risk of bleeding complications (further complicate bleeding by loss of PLT and coagulation factors from cell saver)
“Processing” consisted of both
centrifugal washing &
lipid/leukocyte reduction
To which do we attribute the outcomes?
Limitation #1 Limitation #2 Limitation #3
IV. Limitations:IV. Limitations:
Could have done the same
evaluation with a group of patients just discarding
suction blood if it is a small volume.
Use of cell saver associated with
loss of coagulation factors and PLTs.
Perhaps looking at chest tube loss
post-operatively, and blood product
use?
Please feel free to post questions/comments to OSCP site for
discussion.