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Overview :
Leese et al identified risk factors associated with severe
disease in patients with acute pancreatitis. These can help identify a person at
increased risk for whom additional studies such as contrast enhanced CT may be
indicated. The authors are from the University of Leicester in England.
Parameters:
(1) Imrie
(Glasgow) prognostic score, on admission
(2)
C-reactive protein (CRP) on day 3 after admission, using radial imunodiffusion
with a normal range < 0.01 g/L (see Figure 1, page 230)
(3) white
blood cell count on day 7 after admission
|
Parameter |
Finding |
Points |
|
Imrie prognostic score on admission |
0 – 2 |
0 |
|
|
3 - 9 |
1 |
|
CRP on day 3 |
<= 0.15 g/L |
0 |
|
|
> 0.15 g/L |
1 |
|
WBC count on day 7 |
<= 15 * 10^9/L (<= 15,000 per µL) |
0 |
|
|
> 15 * 10^9/L (> 15,000 per µL) |
1 |
number of risk factors present =
= SUM(points for the 3 parameters)
|
Number of Risk
Factors |
Sensitivity for Severe
Disease |
Specificity for Severe
Disease |
|
1 |
95% |
52% |
|
2 |
65% |
83% |
|
3 |
35% |
98% |
On page 231, the authors give the following equations for
probability of severe outcome:
probability of severe outcome =
= EXP(X) / (1 + EXP(X))
X for day 1 =
= (0.62827 * (initial Imrie score)) + (0.07055 * (initial WBC
count)) – 4.2396
X for day 3 =
= (0.82702 * (on day 3 Imrie score)) + (7.3241 * (CRP on day
3)) – 4.8940
X for day 7 =
= (0.65979 * (on day 7 Imrie score)) + (0.15617 * (WBC count
on day 7)) – 4.9089
where:
• I assume that WBC count used is the (value) * 10^9.
Limitations:
• The
cutoff point for CRP will probably need to be adjusted for different analytic
methods.
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