Karkouti et al developed a prediction rule for identifying a patient who may receive massive (large volume) blood transfusion associated with cardiac surgery. This can help identify a patient who should be targeted for blood conserving strategies. The authors are from Toronto General Hospital and the Reducing Bleeding in Cardiac Surgery Research Group.
Large volume blood loss: >= 5 units of packed red blood cells
Parameters:
(1) age in years
(2) body surface area (BSA)
(3) preoperative shock
(4) preoperative platelet count
(5) preoperative hemoglobin
(6) complexity of surgery
(7) usual blood loss for surgeon
(8) redo operation
(9) scheduling for surgery
(10) duration of circulatory arrest
(11) cardiopulmonary bypass duration
(12) lowest (nadir) cardiopulmonary bypass hematocrit
|
Parameter |
Finding |
Points |
|
age in years |
< 70 years |
0 |
|
|
70-80 years |
0.5 |
|
|
> 80 years |
1 |
|
BSA |
> 1.9 square meters |
0 |
|
|
1.5-1.9 square meters |
0.5 |
|
|
< 1.5 square meters |
1 |
|
preoperative shock |
absent |
0 |
|
|
present |
1 |
|
preoperative platelet count |
> 150,000 per µL |
0 |
|
|
100,000-150,000 |
0.5 |
|
|
< 100,000 per µL |
2 |
|
preoperative hemoglobin |
> 13 g/dL |
0 |
|
|
11-13 g/dL |
0.5 |
|
|
< 11 g/dL |
1 |
|
complexity |
simple (isolated coronary bypass graft or single valve surgery) |
0 |
|
|
complex (other) |
0.5 |
|
usual blood loss for surgeon |
low to moderate |
0 |
|
|
high (above median for institution) |
0.5 |
|
redo operation |
no |
0 |
|
|
yes |
1 |
|
scheduling for surgery |
elective |
0 |
|
|
urgent or emergency |
0.5 |
|
circulatory arrest |
0-30 minutes |
0.5 |
|
|
> 30 minutes |
1 |
|
cardiopulmonary bypass |
< 120 minutes |
0 |
|
|
120-180 minutes |
1 |
|
|
> 180 minutes |
2.5 |
|
lowest hematocrit on bypass |
> 22% |
0 |
|
|
18-22% |
0.5 |
|
|
< 18% |
1 |
where:
• The table from Karkouti (2007) in Appendix 1 shows overlap at age 80 years, BSA 1.5 square meters, preoperative platelet count 100,000 per µL, preoperative hemoglobin 11 g/dL, cardiopulmonary bypass 180 minutes, lowest hematocrit 18%.
• The absence of circulatory arrest (0 minutes) is scored 0.5.
total score =
= SUM(points for all 12 parameters)
Interpretation:
• minimum score: 0.5
• maximum score: 14
• The higher the score the greater the risk of receiving a large blood volume transfusion.
|
Score |
Risk |
|
<= 2.5 |
low |
|
3.0 to 4.0 |
moderate |
|
>= 4.5 |
high |
Specialty: Clinical Laboratory, Surgery, general, Anesthesiology, Emergency Medicine, Critical Care
