What is same sided shifting dullness?

 Same sided shifting dullness is very difficult to demonstrate.
This is used for clinical detection of small amount of free fluid
How to elicit same sided shifting dullness?

• During the examination by conventional method of shifting dullness, turn the patient to the side of flank percussion and not to the opposite side.
•  Now percuss the flank with difficulty which gives a dull note (here. flanks are originally resonant in supine position due to small collection of free fluid).

What is dipping method?

• It is done to palpate viscera in the presence of fluid in peritoneum.
• Preliminary preparations of the patient are the same as done during palpation of liver. 
• It is better to start palpation from right iliac fossa lor dipping method.
• Place the palpating right hand over the abdomen and then tap the abdomen shaply and quickly. 
• The sudden and rapid displacement of liquid will give a tapping sensation over the surface of the enlarged liver or spleen that is comparable to patellar tap
• The sudden thrust displaces the liquid and the displaced liquid pushes ihc organ forward towards the palpating lingers. 
• Many a time the full description of an organ is not possible by dipping method such as palpable or not. tender or non-tender, small or big lump. 
• While palpating the spleen by dipping method, it is better to place the left palm over the left costal margin as done in the conventional method.

How to elicit Shifting dullness?

This method may also be called as shifting tympanicity

• Patient lies supine with thighs flexed.
• Patient is asked to evacuate his/her bladder (full bladder will unnecessarily hamper the midline percussion).
• Now palpate the abdomen (by dipping method) for any visceromegaly (liver, spleen, kidney lump, if any organ is enlarged, avoid percussion over them.
• Starting from the eigastrium percuss in the midline from above downwards. percuss the midline to verify resonance. Note the maximum point of tvmpanicity. Usually it is somewhere around the umbilicus.
• Now percuss laterally to one side (suppose, the right side) from the maximum point of tym-panicity noted in the midline, keeping the pleximeter finger parallel to long axis of abdomen or arbitrary border of the fluid level. 
• When you get a dull note, mark it with a skin pencil but keep on percussing towards the flanks (to diagnose that the dullness is continuous and not a localised one due to colonic growth, faecolith etc.) and again return to the first noted point of dullness.
• Now turn the patient to left lateral position, keeping the fingers in the point of dullness noted in the right flank. Turning is done in such a way that your fingers in the right flank become the highest point of the patient’s body. Now wait for few seconds (usually 1/2 to 1 minute) for the intestine to float up.
• Percuss the dull point noted in the right flank and it will be tympanitic now. Go on percussing upto the end point of the right flank which now shows tympanitic resonance.
• Next go upto the midline and now the midline which was tympanitic initially will be dull on percussion. So the dullness in the right flank changes to tympanitic note and the midline becomes dull from the original tympanicity. This is shifting dullness.
• The same procedure is repeated in the left flank starting from the midline.

Minimal fluid required for demonstration of shifting dullness :
It is said that at least 1 /2 to 1 litre of fluid is required to demonstrate shifting dullness.
Absent shifting dullness in the presence of fluid in the abdomen :
The possibilities are :

• Fluid is encysted i.e. ovarian cyst.
• Small collection of free fluid.
• Loculated ascites in tuberculous peritonitis.

Shifting dullness in the absence of fluid in the abdomen
False positively in paralytic ileus (rare).
What is meant by free fluid in ascites ?
The fluid shifts or changes its position with the intestinal air with change of posture which never
occurs in encysted fluid and thus, shifting dullness is never found in encysted fluid in the abdomen.
Why do we percuss the midline first. in performing shifting dullness ?
While the patient lies supine, the intestine will float in the midline (in health as well as in a patient
of ascites) and will give tympanitic note on percussion. To follow’ the cardinal rules of percussion, we percuss the midline first (tympanitic) and then the flanks (dull) so. we percuss from more resonant to less resonant  area.
Masssive hepatosplenomegaly with ascites : how to elicit shifting dullness ?

• First percuss the midlinc and there will be presence of tympanitic note on percussion. 
• Now ask the patient to sit and again percuss the midline form above downwards.
• In the presence of free fluid in the abdomen, the lower part of midlinc will be dull in sitting position (bladder must be evacuated)
• Actually, in the presence of gross visceromegaly, clinical detection of ascites is very difficult.

Unilateral shifting dullness :

• It is found in splenic rupture and is known as Ballance's sign. 
• The blood present in the left flank becomes clotted (near the spleen) and wont not shift to right side in right lateral position but the blood present in the right side (haemoperitoneum) is shifted to the left side.

How to elicit Fluid thrill?

• Patient lies on his back with thighs flexed
• Place the left hand of the examiner over the left lumbar region of the patient.
• Either the patient or a third person (in the case of a child patient) will put his ulnar border of right hand vertically over the midline of the abdomen and then flick or tap gently the right lumbar region with the right hand.
• A fluid thrill or a pulsation is felt by the hand placed on the opposite lumbar region.
• The purpose of keeping the assistants hand is to dampen any impulse that may be transmitted through the fat of the abdominal wall. 
• Fluid thrill is present when fluid collection in the peritoneal cavity is > 2 litres.
• Absence of fluid thrill and shifting dullness or any of them, does not exclude diagnosis of ascites.

What are the conditions where you get fluid thrill ?
Fluid thrill is present in the presence of fluid in the peritoneal cavity whether it is encysted or free,
fluid thrill may be found in.

• Ascites
• Ovarian cyst.
• Hydramnios
• Rarefy in large hydronephrosis.
• Obesity (false positive)

What is the essential criteria for positive fluid thrill?

• Large amount of fluid (at least 2 litres fluid is necessary to elicit fluid thrill).
• Fluid should remain under tension.
• Fluid thrill may not be present if there is small collection of fluid or the fluid is not present undertension

Is  fluid thrill a definite sign for ascites ?
Fluid thrill is not a definite sign for ascites
How to elicit fluid thrill in the presence of massive splenomegaly or hepatomegaly with ascites ?

• This is often very difficult to form an opinion regarding fluid thrill in the presence of hepatosplenomegaly
• You should not place the palm over the enlarged organ, rather one should tap from that side and the palpating hand is kept on the other side (patient s hand remains vertically in the mldllne).
• If there is gross hepalosplenomcgaly. fluid thrill often remains inconclusive

How to elicit puddle sign?

Puddle's sign

• This sign is elicited to detect the presence of minimal fluid when flanks are resonant.
• The term Puddle sign literally means a small pool of muddy water.
• It can be elicited either by percussion or by auscultopercussion
• Generally  300-400 ml of fluid may be clinically elicited by puddle sign and even as little as 120 ml of fluid can be detected by this method.

How to elicit puddle sign?

• First percuss the abdomen in supine position where you get a tympanitic note in the midline.
• Now place the patient on the hands and knees (knee-elbow position) for 5 minutes and percuss with difficulty over the dependent part of abdomen (near umbilicus) which now reveals a dull note due to shifting of fluid
• Previously resonant umbilical region becomes dull if minimal fluid is present.
• Place a stethoscope over umbilical region and scratch the abdominal wall from periphery towards umbilicus
• A change in the quality of sound is perceived while crossing the fluid column. This sign is false positive in massive splenomegaly and distended bladder.

Pathophysiology of ascites in Cirrhosis

There are numerous causes of ascites, the most common causes are

1. Malignant disease.

2. Cirrhosis.

3. Heart failure. 

Primary disorders of the peritoneum and visceral organs can cause ascites, and they should be considered even in those patients with chronic liver disease (CLD).

The main cause of ascites in cirrhosis is Splanchnic vasodilatation.It is mediated by vasodilators especially nitric oxide.These vasodilators are released when there is shunting of blood into the systemic circulation due to portal hypertension.As cirrhosis advances systemic arterial pressure falls due to severe splanchnic vasodilatation. 

This in turn leads to 

1. Activation of the RAS (renin–angiotensin system) with secondary aldosteronism.
2. Increased sympathetic nervous system activity.
3. Increased atrial natriuretic hormone secretion.
4. Altered activity of the kallikrein–kinin system.

These systems will try to normalise the arterial pressure but they result in salt and water retention.Combination of splanchnic arterial vasodilatation and portal hypertension tend to alter the intestinal capillary permeability, resulting in accumulation of fluid within the peritoneal cavity.