Velmahos developed a model for predicting the probability of a repeat head CT showing additional findings in a patient with minimal head injury. This can help identify patients who may not need a repeat CT examination. The authors are from Massachusetts General Hospital.
Patient selection: head injury with Glasgow coma score 13, 14 or 15
Parameters:
(1) interval between injury and head CT
(2) age of the patient in years
(3) GCS score
(4) number of lesions on initial CT scan
Parameter |
Finding |
Points |
interval between injury and CT |
< 90 minutes |
1 |
|
>= 90 minutes |
0 |
age of patient in years |
<= 65 years |
0 |
|
> 65 years |
1 |
GCS score |
15 |
0 |
|
13 or 14 |
0 |
number of lesions on initial CT |
0 or 1 |
0 |
|
2 or more |
1 |
total score =
= SUM(points for all 4 factors)
Interpretation:
• minimum number of risk factors: 0
• maximum number of risk factors: 4
• The higher the number of risk factors the more likely a repeat CT head scan will be worse.
Interval |
Age |
Number of Lesions |
GCS |
Probability |
>= 90 |
<= 65 |
0 or 1 |
15 |
2% |
>= 90 |
<= 65 |
0 or 1 |
13 or 14 |
5% |
>= 90 |
<= 65 |
2+ |
15 |
5% |
>= 90 |
<= 65 |
2+ |
13 or 14 |
16% |
>= 90 |
> 65 |
0 or 1 |
15 |
6% |
>= 90 |
> 65 |
0 or 1 |
13 or 14 |
17% |
>= 90 |
> 65 |
2+ |
15 |
18% |
>= 90 |
> 65 |
2+ |
13 or 14 |
44% |
< 90 |
<= 65 |
0 or 1 |
15 |
9% |
< 90 |
<= 65 |
0 or 1 |
13 or 14 |
28% |
< 90 |
<= 65 |
2+ |
15 |
27% |
< 90 |
<= 65 |
2+ |
13 or 14 |
56% |
< 90 |
> 65 |
0 or 1 |
15 |
28% |
< 90 |
> 65 |
0 or 1 |
13 or 14 |
57% |
< 90 |
> 65 |
2+ |
15 |
59% |
< 90 |
> 65 |
2+ |
13 or 14 |
83% |
Specialty: Surgery, orthopedic, Emergency Medicine, Critical Care, Surgery, general
ICD-10: ,