Meniscus Sign & Fluid in Abdomen

Note: This post is in respond to some questions that someone asked me.

1. What is meniscus sign and its importance?

2. How to do fluid thrill, shifting dullness, splashing sound?

Regarding the first question, meniscus sign. It can refer to 2 things, which I don't know which one is your specialist referred to.

Firstly, it can be referring to the curve that we saw on CXR of a patient with pleural effusion.

• In initial phase of pleural effusion we can only see blunting of the costo-pleural angles.
• In later phase we can see the fluid increase, but the fluid level is not flat, but a upward concave curve, which raise up at the lateral of the chest wall
• In severe pleural effusion we see the whole lung field become white.
• So regarding why is it important. My surgery teacher like to emphasized the shape of the fluid level.
• If curve (meniscus sign), this is a pleural effusion, i.e. only fluid in pleural cavity.
• If flat fluid level, this is a pyopneumothorax, i.e. there are both fluid and air in the pleural cavity, hence different management.

Secondly, it can also refer to the crescent moon-shaped air space in the cavity, which is partial filled by something.

• E.g. in mycetoma, aspergillosis of lung.
• Try imagine a round spherical cavity, and a ball of smaller diameter is place in that cavity.
• The remaining air space in that cavity will appear like a crescent moon on CXR. Hence also known as crescent sign.

Second question is regarding the physical examination of fluid in the peritoneal cavity.

• In Russia the therapy teacher taught a different way of examine, but same principle.
• The principle is that the ascitic fluid will move around (shifting) when the patient change position.
• Imagine turning around a bottle which is half-filled with water.
• So in Russia, what the teacher does is when patient lies down supine on the bed, she percuss the abdomen from top to bottom to find the fluid level.
• Then she ask the patient to change position, either sits up, or lies on the side. Then she do the same thing again to find the fluid level.
• If the fluid level (or the position of the dullness caused by the fluid) is different, it means there is fluid in peritoneal cavity.

So the same principle apply for shifting dullness, only different method.

• Patient is lying supine on the bed, examiner do percussion from the top, or the umbilicus, down to the one side, e.g. down to the right side, to find the fluid level (the place when the percussion note change from resonant to dull).
• Without removing the middle finger of your left hand away from the abdomen, ask the patient to turn to the opposite side, which is the left side.
• Then percuss at the finger which you didn't remove just now, if the percussion note is resonant instead of dull, there is presence of shifting dullness, i.e. the dullness of the fluid has shifted to other place because the patient change position. And this indicate the presence of ascitic fluid in the abdomen.
• However shifting dullness can only be elicit when the fluid is not to much.
• If there is too much fluid, the dullness caused by the fluid is still at the same place.
• Imagine again, turning around two bottles, one is half-filled with water, and the other one is completely filled with water.

So in order to check for the presence of massive ascitic fluid, the fluid thrill is done.

• Ask an assistant or the patient himself to put the edge of the hand in the midline of the abdomen (like a karate person chopping wood with his hand).
• Put both hands on the the lateral sides of the abdomen, one on left, one on right.
• One of the hand, e.g. left hand lightly tap or press on the side of the abdomen (another method is to use middle finger to flick on the side of the abdomen).
• If the right hand on the opposite side of the abdomen can feel the vibration (the thrill from the fluid), this indicate the presence of abundant fluid in the abdominal cavity.
• The principle is that as you tab / press / flick the abdomen, the fluid vibrates, and the vibration travels to the opposite side.
• However fluid thrill cannot only be elicit when the fluid is too little, because large amount of fluid is needed to cause the vibration or thrill.
• By the way, the hand in the midline is used to prevent the vibration of the skin of abdomen to travel to the opposite side.

Source: http://www.profizham.medicineukm.com/

I am not quite sure about splashing sound. But I remember in Russia got learn something like this.

• Left hand fix at the xiphoid, right hand with 4 flexed fingers palpate the epigastrium, and try to hear for splashing sound.
• Splashing sound (succussion) is a sign that presence in patient with pyloric stenosis.
• But I don't know is this what the specialist wants.
• In the internet I found a different method. "Succusion splash is a splashing heard when rocking a patient with a fluid collection in the pleural space, abdominal cavity, stomach or elsewhere."

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For more information about physical examination, you can refer this site:
http://www.profizham.medicineukm.com/shortcase.html

http://cme-vsmu.blogspot.com/

Recommended books for physical examinations:

• Clinical Examination, a systematic guide to physical diagnosis by Talley & Connor
• X'press Revision in Short Case by Chew Nee Kong, published by Universiti Malaya

These 2 books can get from Kamal bookstore.

• The Medical Short Case: An Examination Guide published by Penang Medical Practitioners' Society
• Pacing the PACES by Eow Gaik Bee

These 2 books are not available at Kamal, but can get from Penang hospital, or you can order online through this site below
http://internalmedicinemrcp.blogspot.com/2011/07/mrcp-paces-reader.html

I hope these information can help you.

Last but least, remember what the Lord says,

He said to me, "My grace is sufficient for you, 

for my power is made perfect in weakness."
Therefore I will boast all the more gladly about my weaknesses, 

so that Christ's power may rest on me.
That is why, for Christ's sake, I delight in weaknesses, 

in insults, in hardships, in persecutions, in difficulties.
For when I am weak, then I am strong. 

2 Corinthians 12:9-10