4. 腹部造影CT後の腎症予測Nomogram
American Journal of Emergency Medicine (2011) 29, 412–417
ERにおいて緊急造影腹部CTを撮影した
750名のRetrospective study
– 34/750(4.5%)で造影剤腎症(+).
– 年齢と基礎のSCr値が有意に造影剤腎症発症に関連.
年齢1yr毎 OR1.04[1.02-1.07], Cr値1mg/dL毎 2.51[1.67-3.78]
– リスクに応じたNomogramを作成.(次ページ)
4
5. Previous studies have shown that CIN is associated with a 5. Limitations
prolonged hospital length of stay and an increase in hospital
and long-term mortality [2,9,13,16]. It is for this reason that
This study has several limitations. First, the selection of
we need to identify patients at high risk of CIN to seek
patients might be biased because only patients with both
alternative diagnostic procedures. However, the clinical
baseline and follow-up SCr levels were included in the
needs for diagnostic imaging may outweigh the potential
analysis. Although the model may be biased, the nomogram
risks of CIN in many emergency situations. In these cases,
was internally validated. This problem can be solved by
efforts should be devoted to reducing the risk of CIN by
external validation; however, we could not perform it. Second,
reducing the volume of contrast media, providing preventive
the number of cases with nephropathy was modest because the
measures such as N-acetyl cysteine or normalizing the
risk of nephropathy in patients with normal renal function is
physiologic deterioration caused by underlying disease. The
low (only 2.6%) and most study patients (86.3%) had normal
most important and first step is the identification of the
renal function. This modest number of cases could expose the
patients with risk of nephropathy.
model to the risk of overfitting. However, that risk was
Nomograms are a useful bedside tool for clinical decision
minimized by performing internal validation in this study.
making [17,18] without the need for complex computer
software for the calculation of individualized probability.
This is similar to scoring system used in pneumonia severity
index [19]. Though it looks more complex than scoring 6. Conclusions
system, this graphical presentation has some advantages over
scoring system. For example, continuous variable such as
Fig. 1 Nomogram to predict nephropathy after receiving emergency A-CECT. SCr indicates initial SCr emergency
The individual risk of nephropathy following
(mg/dL).
log-transformed scales should be converted to categorical if A-CECT can be predicted by an internally validated
American Journal of Emergency Medicine (2011) 29, 412–417
ractice. Therefore, we treated the variables of renal function with advancing age but also du
a
Table 4 etiologies as risk factors for nephropathy. presence of more comorbidities. Prior studies in
lternative Diagnostic performances at each level of predicted probabilities
ally intravenous administration of contrast media
Sensitivity Specificity undergoingPositivehave shown that diabetes LR o
PCI LR Negative with
ered as having lesser(89.7-100) the development of
1% 100 risk for 18.2 (15.4-21.2) diabetic chronic renal failure (CRF) were related
1.22 (1.18-1.26) NA
pared with intra-arterial administration. In 74.0 (70.6-77.2) [9,13,14]. However, diabetes was not an indepen
5% 67.6 (49.5-82.6) contrast 2.60 (2.00-3.39) 0.44 (0.27-0.71)
15% 20.6 (8.7-37.9) 96.6 (95.1-97.8)
studies involving intra-arterial administration of factor in this study. This difference 0.82 (0.69-0.98) t
6.14 (2.85-13.2)
may be due
LR indicates likelihood ratio; NA, not applicable.
media, there presented few studies ratio with 95% confidence intervals.that although the prevalence of diabetes in PCI st
a
Values are
are a as percentages or involving intrave-
inistration of contrast media [10]. In the subgroup been at least 20%, the prevalence of diabetes in
6. induced AKI, it is not without its limitations. First, rates than those without contrast-induced AKI. There-
patients were in the study according to a single-center fore, it is necessary to study whether withholding
design. Second,造影剤腎症のリスクをPropensity-matched cohortで評価 the inci-
the study is an observational study ACE inhibitors/ARBs before CAG decreases
rather than a controlled interventional trial; random dence of contrast-induced AKI and improves long-
allocation to either ACE/ARB阻害薬は造影剤腎症のリスクとなり得る.
– the RAAS treatment group or term survival rates.
untreated group was not performed. To address these Despite these limitations, our study is the only large
issues, we used propensity score matching to mini- 利尿薬はリスクファクター.
– 他には貧血, 低アルブミン, observational cohort analysis with propensity score
mize the differences in baseline characteristics. Never- matching that provides evidence that RAAS blockade
theless, the propensity score approach has limitations exacerbates contrast-induced AKI in patients undergo-
in terms of determining whether the comparison groups ing CAG.
are truly matched; the propensity score may meet In conclusion, although the role of RAAS blockade
statistical criteria but there still may be important in the development of contrast-induced AKI is de-
Am J Kidney Dis. 60(4):576-582
Table 3. Risk Factors for Contrast-Induced AKI on Multivariable Logistic Regression Analysis in the Matched Cohort
Variable Unadjusted OR (95% CI) P Adjusted OR (95% CI) P
ACEi/ARB use 1.93 (1.46-2.55) Ͻ0.001 1.43 (1.06-1.94) 0.02
CKD 2.21 (1.68-2.92) Ͻ0.001 1.54 (1.15-2.08) 0.004
Hemoglobin Ͻ10 g/dL 2.72 (1.89-3.92) Ͻ0.001 1.74 (1.16-2.63) 0.008
Albumin Ͻ3.5 g/dL 3.03 (2.26-4.05) Ͻ0.001 2.14 (1.54-2.97) Ͻ0.001
Contrast volume (per 100-mL increase) 1.27 (1.10-1.46) Ͻ0.001 1.38 (1.19-1.61) Ͻ0.001
Diuretic use 3.76 (2.85-4.94) Ͻ0.001 2.89 (2.14-3.90) Ͻ0.001
LVEF Ͻ40% 1.79 (1.05-3.05) 0.006 1.68 (0.95-2.97) 0.08
Age (per 10-y increase) 1.26 (1.13-1.42) Ͻ0.001 1.07 (0.95-1.07) 0.3
Diabetes 1.49 (1.01-2.22) 0.05 1.22 (0.80-1.87) 0.4
Male sex 1.02 (0.78-1.34) 0.9
Statin use 0.80 (0.59-1.07) 0.1
Abbreviations: ACEi, angiotensin-converting enzyme inhibitor; AKI, acute kidney injury; ARB, angiotensin receptor blocker; CI,
6
confidence interval; CKD, chronic kidney disease; LVEF, left ventricular ejection fraction; OR, odds ratio.
