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
Specialty: Clinical Laboratory, Surgery, general, Anesthesiology, Emergency Medicine, Critical Care
