Martinez et al identified risk factors associated with mortality in patients with emphysema. This can help identify a patient who may benefit from closer monitoring and more aggressive management. The authors are from multiple institutions in the United States that participated in the National Emphysema Treatment Trial (NETT).
NOTE: The risk factors listed in the abstract and on page 1329 partially overlap and reflect significant variables for multivariate analysis models 1 and 2 (Table 3, page 1330). I will combine both lists into 1.
|
Abstract |
Discussion |
Model 1 |
Model 2 |
|
age in years |
age in years |
age in years |
age in years |
|
oxygen use |
oxygen use |
oxygen use |
|
|
|
hemoglobin |
|
hemoglobin |
|
total lung capacity |
|
total lung capacity |
|
|
residual volume |
residual volume |
residual volume |
residual volume |
|
|
diffusion capacity |
|
diffusion capacity |
|
exercise workload |
exercise workload |
exercise workload |
|
|
distribution emphysema |
distribution emphysema |
distribution emphysema |
distribution emphysema |
|
perfusion ratio |
|
perfusion ratio |
perfusion ratio |
|
modified BODE index |
modified BODE index |
|
modified BODE index |
Parameters:
(1) age in years
(2) oxygen use
(3) hemoglobin
(4) total lung capacity as percent of predicted
(5) residual volume as percent of predicted
(6) diffusion capacity of carbon monoxide
(7) maximum CPET workload
(8) difference in severity of emphysema between upper and lower lobes
(9) perfusion ratio between upper and lower lobes
(10) modified BODE index (using the UCSD SOBQ in place of the MRC dyspnea scale)
|
Parameter |
Finding |
Points |
|
age in years |
< 70 years of age |
0 |
|
|
>= 70 years of age |
1 |
|
oxygen use |
no |
0 |
|
|
yes |
1 |
|
hemoglobin |
> 13.3 g/dL |
0 |
|
|
<= 13.3 g/dL |
1 |
|
total lung capacity |
< 140 percent of predicted |
0 |
|
|
>= 140 percent of predicted |
1 |
|
residual volume |
< 262 percent of predicted |
0 |
|
|
>= 262 percent of predicted |
1 |
|
diffusion capacity |
> 21 mL CO per min per mm Hg |
0 |
|
|
<= 21 mL CO per min per mm Hg |
1 |
|
maximum CPET workload |
high (> 25 W female, > 40 W male) |
0 |
|
|
low (<= 25 W female, <= 40 W male) |
1 |
|
emphysema severity |
upper >= lower |
0 |
|
|
upper < lower |
1 |
|
perfusion ratio |
> 0.14 |
0 |
|
|
<= 0.14 |
1 |
|
modified BODE index |
0 to 6 |
0 |
|
|
7 to 10 |
1 |
where:
• The article did not include a risk score.
• The hazard ratios for the risk factors were fairly close.
• The 40th percentile for maximal workload is 25 W for females and 40 W for males. High exercise capacity is above this, while low is at or below.
total number of risk factors =
= SUM(points for all 10 parameters)
Interpretation:
• minimum number of risk factors: 0
• maximum number of risk factors: 10
• The higher the number of risk factors the greater the patient's mortality risk.
Specialty: Pulmonology
ICD-10: ,
