ASCITES

Dr WAQar
MBBS, MRCP, Int. Medicine (London)
Specialist cert. exam, Endocrinology & DM (London)
ASST. PROFESSOR

Leenah Turjoman ♥

Definition

Accumulation of more than 25 cc of fluid in the peritoneal cavity is called ascites.

Normally, only about 25 cc fluid is present in the cavity
A little amount of fluid is needed in the cavity so there is no friction among intestines

Detection Threshold:

At least 1.5 L fluid should be present in the abdomen so as to be detected by examination. If less than this, shifting dullness and fluid thrill will be negative.

Confirmation:

25cc - 1.5L of fluid can be detected by US (Ultrasound)

Etiologies of Ascites

Liver disease (cirrhosis)
- Cancer
- Leads to lack of albumin
- So fluid goes out into interstitial spaces
- Results in ascites
- Normally, albumin keeps fluid in bed by oncotic pressure
Portal HTN
- Could be due to blood clot or pancreatitis
Low serum albumin due to any cause (cirrhosis, low protein diet, protein malabsorption, urinary albumin loss)
- e.g., nephrotic syndrome
Heart failure (due to backpressure)
- On the right side
- Causes hepatomegaly
- Fluid comes out
Renal failure (due to fluid retention)
- Leads to fluid accumulation, causing:
  - Ascites
  - Pleural effusion
  - Pulmonary edema
  - Pedal edema
Peritonitis
- Infection causes all fluid to come out into peritoneal cavity
Mets to the peritoneum
- Peritoneum becomes inflamed and fluid comes out in the cavity

Step Wise Approach

Take a detailed history (keeping in view all the etiologies)
Physical examination (keeping in view all the etiologies)
CBC, LFTs, Electrolytes, creatinine
Ascitic fluid analysis
Imaging studies (keeping in view all the etiologies)

Classification

Ascites can be divided into 2 main types according to the protein concentration of the fluid:

TRANSUDATE: Protein less than 30g/L in the ascitic fluid
EXUDATE: Protein more than 30 g/L

A better way of classification is the SAAG ratio (Serum to Ascites Albumin Gradient) - (difference)

What is SAAG?

Serum albumin minus ascitic fluid albumin (albumin difference)

This difference can be more than 1.1g/100cc or less than 1.1g/100cc

Classification:

SAAG Value	Category
SAAG > 1.1	High gradient
SAAG < 1.1	Low gradient

Causes of Ascites by SAAG

SAAG > 1.1

a) Cirrhosis with/portal HTN
b) Portal HTN due to any other cause
c) Heart failure
d) Renal failure

SAAG < 1.1

a) Bacterial & fungal peritonitis
b) Tuberculous peritonitis
c) Nephrotic syndrome
d) Pancreatitis
e) Low serum albumin
f) Mets to the peritoneum

Some Other Types of Ascites

Hemorrhagic ascites: due to malignancy
- Either mets or malignancy of Peritoneum
Chylous ascites: Collection of lymph in the abdominal cavity
- Rich in fats → milky appearance
- e.g., in lymphomas, TB peritonitis
- These conditions cause damage to lymphatic channels so lymph comes out into peritoneal cavity
- Triglycerides are carried with proteins in the blood, they are not water soluble
- (Chilomicrons = Triglycerides = Fat)

Clinical Images

Ascites

Ascites Due to Kwashiorkor

Investigations in Ascites

Paracentesis (Ascitic Tap)

Every new patient with ascites should get a “diagnostic” tap:

Take out 10-20 cc fluid
Check:
- Albumin (to calculate SAAG)
- Neutrophils (to see infection)
- RBC
- Gram stain & culture
- Cytology (malignant cells)
- Amylase levels (in suspected pancreatic ascites) → not routinely done

Management of Ascites

General Principles

Low salt & Diuretics
Water intake restriction (because salt retains water in the body)
Paracentesis

In very resistant ascites, a procedure called TIPS is sometimes used (transjugular intrahepatic porto-systemic shunt).

TIPS Mechanism: Joining Portal with hepatic circulation so pressure in Portal vein is diverted to hepatic system (reducing pressure in Portal vein)

TIPS Procedure

Medical Management

1) Low salt & water restriction

Less than 2 g/d of salt (less than ½ teaspoon)

2) Diuretics

First Choice:

Spironolactone (Aldactone) → in liver disease
- Side effects: gynecomastia, hyperkalemia

Additional:

Can add Lasix (Furosemide) if needed

Important: Reduce ascites gradually (0.5 to 1 kg weight loss daily). Too much weight loss “suddenly” is not good!

In 95% of cases, ascites can be controlled by low salt & diuretics alone.

Therapeutic Paracentesis

Indication:

Done if medicines don’t help (resistant ascites) or very big ascites causing respiratory difficulty

Procedure Details:

Upto 7 L can be removed at one time
Removal of more than 7L can cause problems:
- Hypotension
- Renal failure
- Encephalopathy
Can also occur if rapidly reduce ascites by diuretics
I.V. albumin given at the time of paracentesis can prevent these complications

Procedure Notes:

No need for anesthesia
30 min and fluid will come out

Complications of Ascites

Albumin Considerations

Patient with liver cirrhosis: albumin is not synthesized, leading to ascites, but albumin is not given as treatment because albumin has very short half life, so practically can’t be given for life.

Albumin not given for nephrotic syndrome because if given, more albumin will be filtered through kidney and more damaging to kidney

Key Complications

Remember 3 complications of ascites:

SBP (Spontaneous bacterial peritonitis)
Respiratory distress
Umbilical hernia

How to Approach the Patient

Take a detailed history (keeping in view the causes of ascites)
Do appropriate examination
Order investigations
Give treatment to remove the ascitic fluid
Treat the cause

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