|
Overview :
Magovern et al identified preoperative factors associated
with the need for transfusion during coronary artery bypass surgery. These can
be used to identify a patient who may require multiple units during and after
the operation. The authors are from Allegheny General Hospital in
Pittsburgh.
Parameters known prior to surgery:
(1) timing
of the operation
(2)
cardiogenic shock (systolic blood pressure < 90 mm Hg, or mean arterial blood
pressure < 50 mm Hg)
(3)
catheterization-induced coronary occlusion
(4) body
mass index
(5) left
ventricular ejection fraction
(6) age of
the patient in years
(7) gender
of the patient
(8) red
cell mass (anemia defined as male gender and hemoglobin <= 12.5 g/dL; female
gender and hemoglobin <= 11 g/dL; need for blood transfusion in week before
surgery)
(9)
peripheral vascular disease
(10)
diabetes mellitus
(11) serum
creatinine
(12) serum
albumin
(13) redo
operation
|
Parameter |
Finding |
Points |
|
timing of the operation |
emergency |
4 |
|
|
urgent |
3 |
|
|
other |
0 |
|
cardiogenic shock |
absent |
0 |
|
|
present |
3 |
|
catheterization induced coronary occlusion |
no |
0 |
|
|
yes |
3 |
|
body mass index |
low (<= 24 kg per square meter) |
2 |
|
|
normal or high |
0 |
|
left ventricular ejection fraction |
< 30% |
2 |
|
|
>= 30% |
0 |
|
age of the patient in years |
<= 74 years of age |
0 |
|
|
> 74 years of age |
2 |
|
gender of the patient |
male |
0 |
|
|
female |
2 |
|
red cell mass |
low (anemia) |
2 |
|
|
normal |
0 |
|
peripheral vascular disease |
absent |
0 |
|
|
present |
1 |
|
diabetes mellitus |
insulin dependent |
1 |
|
|
not insulin dependent |
0 |
|
|
absent |
0 |
|
serum creatinine |
<= 1.8 mg/dL |
0 |
|
|
> 1.8 mg/dL |
1 |
|
serum albumin |
>= 4.0 g/dL |
0 |
|
|
< 4.0 g/dL |
1 |
|
redo operation |
no |
0 |
|
|
yes |
1 |
transfusion risk score =
= SUM(points for all 13 parameters)
Interpretation:
• minimum
score: 0
• maximum
score: 25
• The
higher the score the greater the likelihood of being transfused and the greater
the number of units transfused.
|
Transfusion Risk
Score |
Probability of Being
Transfused |
|
0 or 1 |
25-33% |
|
2 to 6 |
66% |
|
>= 7 |
95% |
from Figure 2, page 30
|
Transfusion Risk
Score |
Mean Number of Units
Transfused |
|
0 |
1.6 |
|
1 or 2 |
3.0 |
|
3 or 4 |
4.5 |
|
5 or 6 |
5.5 |
|
7 or 8 |
6.3 |
|
>= 9 |
9.0 |
from Figure 3. page 31
|