检测

目的

方案

结果

解释

内源性ACTH

鉴别PDH和AT

早晨8点~10点间采集血浆，血样需特殊处理。

<10pg/ml

AT

10-45 pg/ml

无诊断意义

>45 pg/ml

PDH

ACTH刺激后可的松浓度：

ACTH刺激试验

诊断库兴氏综合征

ACTH凝胶*：2.2IU/kg IM，ACTH给予前和之后2小时采集血浆；或合成的ACTH*：0.25mg/犬 IM，ACTH给予前和之后1小时采集血浆

>24μg/dl

强烈暗示存在†

19-24μg/dl

暗示存在‡

8-18μg/dl

正常

<8μg/dl

医源性库兴氏综合征

给予地塞米松4小时后

给予地塞米松8小时后

低剂量地塞米松抑制试验

诊断库兴氏综合征，并鉴别PDH和AT

地塞米松：0.01mg/kg IV，给药前和之后4小时、8小时采集血浆

—

<1.4μg/dl

正常

<1.4μg/dl

>1.4μg/dl

PDH

<50%给药前浓度

>1.4μg/dl

PDH

—

>1.4μg/dl且<50%给药前浓度

PDH

给药4小时后浓度>1.4μg/dl且>50%给药前浓度

>1.4μg/dl

PDH或AT

ACTH给药后

地塞米松抑制试验和ACTH刺激试验结合试验

诊断库兴氏综合征

地塞米松：0.01mg/kg IV，给药前和给药后2小时采集血浆；然后ACTH凝胶：2.2IU/kg或合成的ACTH：0.25mg/犬 IM，给药后1小时和2小时（ACTH凝胶）或30分钟和60分钟（合成的ACTH）采集血浆

<1.5μg/dl

8-18μg/dl

正常

>1.5μg/dl

8-20μg/dl

暗示

>1.5μg/dl

>20μg/dl

强烈暗示存在

<1.5μg/dl

>20μg/dl

暗示存在

<1.5μg/dl

<8μg/dl

医源性库兴氏综合征

地塞米松给予后可的松浓度

高剂量地塞米松抑制试验

鉴别PDH和AT

地塞米松：0.1mg/kg IV，给药前和之后8小时采集血浆

<50%给药前浓度

PDH

<1.4μg/dl

PDH

≥50%给药前浓度

PDH或AT

Idexx Low-dose Dexamethasone Suppression Test

4-hour cortisol level

8-hour cortisol level

interpretation

<1μg/dL

<1μg/dL

Normal

1-1.5μg/dL

1-1.5μg/dL

Inconclusive, consider repeating in 6-8weeks

>1.5μg/dL and >50% of baseline

>1.5μg/dL and >50% of baseline

Consistent with Cushing’s syndrome; perform high-dose dexamethasone suppression, endogenous ACTH concentration and/or abdominal ultrasound to discriminate between PDH and ATH

<1.5μg/dL or <50% of baseline

>1.5μg/dL and >50% of baseline

Consistent with PDH

>1.5μg/dL and >50% of baseline

>1.5μg/dL and <50% of baseline

Consistent with PDH

Idexx ACTH Stimulation Test

Pre-ACTH

Interpretation

Post-ACTH

interpretation

<2μg/dL

Must evaluate in conjunction with post-ACTH result. If both results are <2μg/dL, results are consistent with hypoadrenocorticism. Begin treatment with mineralocorticoid and/or glucocorticoid as appropriate.

<2μg/dL

Ideally, should be evaluated in conjunction with pre-ACTH result. If both results are <2μg/dL, results are consistent with hypoadrenocorticism. Begin treatment with mineralocorticoid and/or glucocorticoid as appropriate.

2-6μg/dL

Norml

2-6μg/dL

Inconclusive

>22μg/dL

Consistent with Cushing’s syndrome; Perform high-dose dexamethasone suppression.

6-18μg/dL

Normal

18-22μg/dL

Equivocal; Cushing’s syndrome possible.

>22μg/dL

Consistent with Cushing’s syndrome; perform high-dose dexamethasone suppression to discriminate between PDH and ATH, ACTH level and/or abdominal ultrasound.