Table 3

The 4 classes of risk defined by the FLAM score

FLAM peak value
n
Pulmonary complications
Respiratory Failure
Death

0 – 9
236
8 (3.3%)
0
0
10 – 18
42
32 (76.2%)
6 (18.7%)
1 (3.1%)
19 – 27
8
6 (87.5%)
4 (57.1%)
2 (28.7%)
> 27
14
14 (92.8%)
9 (69.2%)
6 (46.1%)

Considering the highest FLAM value recorded, it was possible to define 4 class with increasing risk of pulmonary complication and severity. It was called "the rule of 9" because class are identified by multiple of nine.

Leo et al. Journal of Cardiothoracic Surgery 2006 1:34   doi:10.1186/1749-8090-1-34