Young man with RLQ pain

這位大三生,右下腹痛,很瘦,
電腦斷層無法區分出是不是急性闌尾炎,
因此外科醫師照會我的超音波來看是不是急性闌尾炎。

影片中由腹部超音波探頭掃描後切換側線形探頭,
一般掃描急性闌尾炎時會先將探頭橫向掃描放在ASIS
(Anterior superior iliac spine)的位置,
定位出iliac bone, iliopsoas muscle & iliac vessels
然後將探頭往頭側和往腳側水平移動,尤其是疼痛點的掃描。

目標是看到Terminal ileum, ileocecal valve,再來看有無腫大的闌尾。
這個個案腹部探頭的掃描很清楚的可以看到腫大的闌尾,
可以看到沿iliopsoas muslce的內緣往骨盆深處去,
深度約4-5分分,所以切換成線形探頭來看又更清楚些,
近端是好的,但中後段的闌尾是明顯腫大,
而且週圍的脂肪也呈現發炎時會出現的高回音變化。
小孩和愈瘦的患者呈現右下腹痛時,
先利用腹部探頭做系統性的ABDOMEN掃描,
再切換至線形探頭來掃描,你對急性腹痛的掌握度會更高喔 !!

嵌頓型疝氣

POCUS findings
1. Transverse scan from right scrotum upward
2. Visible testicle and fluid within scrotum
3. Small bowel with bowel content also noted within scrotum
4. Trace back to peritoneal cavity

臨床懷疑嵌頓性的疝氣時,POCUS的潛在應用價值
1。確認腫脹的病變是不是卡住的腸道構造
2。可找尋腹壁的缺損處,可協助復位時的參考
3。確認是否有腹內小腸阻塞的病變
4。都卜勒功能可協助評估血流的狀態
5。腹部探頭用來看腹內合併的病變; 線形探頭可用來看卡住部位的細節

深部靜脈栓塞

Leg swelling with shinny skin for 3-4 days.
Here is the other view to observe thrombus.
POCUS information:
1. Power Doppler function
2. Longitudinal scan on middle thigh (adductor canal)
3. Echogenic thrombus & filling defect noted within femoral vein

前年有發過一個文:

深部靜脈栓塞(DVT)超音波掃描教學

相信許多急重症的專家們對POCUS診斷DVT都不陌生,
很多人也都是診斷的高手。

上面的這段影片理論上不是急診診斷DVT時會看到的畫面,
因為大多數時候
1. B mode就夠用了,很少開啟都卜勒功能
2. 起始的掃描應該是和血管垂直的橫向掃描開始,而不是這段中的縱向掃描
3. 最重要的診斷依據為Compression test

但是當你對一個掃描技巧愈來愈熟練後,
嘗試不同的角度、探頭、功能和設定,相信會有更多不同的體會和認識。

STONE score可以用來預測尿路結石,但不足以做為取消CT檢查的依據

2014年的研究STONE計分:用來預測沒有併發症的尿路結石
指出若計分為高可能性的這一群,應該是可以免去進一步CT檢查
這個評分當然得接受外部挑戰,
在2016年Annals of Emergency Medicine的這篇研究中,
利用之前進行的一個隨機大型結石研究資料進一步分析,Ultrasonography versus computed tomography for suspected nephrolithiasis. (NEJM 2014),
STONE score比醫師的猜測來得準些,但AUC=0.78並不算很好

下圖所示,確實可以依評分的分類來預測尿路結石,
分數愈高,結石的可能性愈高,其他原因的可能就愈低,
但是比原始研究結果差
而且其中的一項指標Race並不足以用來做為預測之用

最高分數的這組,Sensitivity 53%, Specificity 87%
因此雖然可以用來預測尿路結石,
但仍不足以用來做為不用排CT檢查的依據。

External Validation of the STONE Score, a Clinical Prediction Rule for Ureteral Stone: An Observational Multi-institutional Study

Ralph C. Wang, MD,* Robert M. Rodriguez, MD, Michelle Moghadassi, MPH, Vicki Noble, MD, John Bailitz, MD, Mike Mallin, MD, Jill Corbo, MD, RDMS, Tarina L. Kang, MD, Phillip Chu, PhD, Steve Shiboski, PhD, and Rebecca Smith-Bindman, MD

Ann Emerg Med. 2016 Apr; 67(4): 423–432.e2.

Abstract

Study objective

The STONE score is a clinical decision rule that classifies patients with suspected nephrolithiasis into low-, moderate-, and high-score groups, with corresponding probabilities of ureteral stone. We evaluate the STONE score in a multi-institutional cohort compared with physician gestalt and hypothesize that it has a sufficiently high specificity to allow clinicians to defer computed tomography (CT) scan in patients with suspected nephrolithiasis.

Methods

We assessed the STONE score with data from a randomized trial for participants with suspected nephrolithiasis who enrolled at 9 emergency departments between October 2011 and February 2013. In accordance with STONE predictors, we categorized participants into low-, moderate-, or high-score groups. We determined the performance of the STONE score and physician gestalt for ureteral stone.

Results

Eight hundred forty-five participants were included for analysis; 331 (39%) had a ureteral stone. The global performance of the STONE score was superior to physician gestalt (area under the receiver operating characteristic curve=0.78 [95% confidence interval {CI} 0.74 to 0.81] versus 0.68 [95% CI 0.64 to 0.71]). The prevalence of ureteral stone on CT scan ranged from 14% (95% CI 9% to 19%) to 73% (95% CI 67% to 78%) in the low-, moderate-, and high-score groups. The sensitivity and specificity of a high score were 53% (95% CI 48% to 59%) and 87% (95% CI 84% to 90%), respectively.

Conclusion

The STONE score can successfully aggregate patients into low-, medium-, and high-risk groups and predicts ureteral stone with a higher specificity than physician gestalt. However, in its present form, the STONE score lacks sufficient accuracy to allow clinicians to defer CT scan for suspected ureteral stone.

Clarius的影像表現: L7

前幾天發了個開箱文: Clarius的初體驗
超音波最重要的就是影像的表現了,
今天一起來看看其中的一個探頭L7的表現如何。

急診人在意的就是呼吸道的處置,
呼吸道的部份夠清楚,才讓人有安心感,
這段頸部胸骨上的橫向掃描中,
可以清楚看見Thyroid, trachea, esophagus and CCA,
用來進行氣管插管的確認和鼻胃管的確認應該是可以接受的。
(這是線形探頭L7掃描Airway & Thyroid的影像)

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