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The PSE (Portal Systemic Encephalopathy) Index of Conn et al

Purpose: To evaluate a patient with portal systemic encephalopathy using the PSE index of Conn et al.

Description

The PSE (Portal Systemic Encephalopathy) Index can be used to evaluate the severity of the encephalopathy by combining different clinical and laboratory findings. This can be used to monitor the patient over time and to evaluate the effect of therapeutic interventions. The authors are from multiple VA and university hospitals from Boston to Richmond.


Parameters:

(1) mental state

(2) trailmaking test time (time required to complete a trailmaking test)

(3) EEG changes

(4) asterixis

(5) arterial ammonia

 

Parameter

Finding

Points

mental state

no abnormality

0

 

minimal mild changes, impaired ability to add or subtract, shortened attention span, trivial lack of awareness, etc.

1

 

lethargy, disoriented to time

2

 

somnolent or semi-stuporous

3

 

comatose

4

trailmaking test time

<= 30 seconds

0

 

31 - 50 seconds

1

 

51 - 80 seconds

2

 

81 - 120 seconds

3

 

> 120 seconds

4

EEG changes

Grade 0

0

 

Grade 1

1

 

Grade 2

2

 

Grade 3

3

 

Grade 4

4

asterixis

no flapping

 

 

rare flapping

1

 

occasional, irregular flapping

2

 

frequent flapping

3

 

almost continuous flapping

4

arterial ammonia

<= 150 µg/dL

0

 

151 - 200 µg/dL

1

 

201 - 250 µg/dL

2

 

251 - 300 µg/dL

3

 

> 300 µg/dL

4

 

where:

• Ammonia testing is somewhat unreliable with a high coefficient of variability. Results also vary with the method and specimen handling.

 

PSE Sum =

= (3 * (points for mental status)) + SUM(points for the remaining 4 items)

 

Since not all of the measures can be performed in a comatose patient, the PSE index is calculated based on the items that can be evaluated.

 

PSE index =

= (PSE sum observed) / (maximum PSE sum for testable items)

 

PSE efficacy index =

= ((PSE index before therapy) - (PSE index after therapy)) / (PSE index before therapy)

 

Interpretation:

• minimum PSE sum: 0

• maximum PSE sum: 28

• The higher the PSE sum the more severe the encephalopathy.

• minimum PSE index: 0

• maximum PSE index: 1.0

• minimum PSE efficacy index: 0

• maximum PSE efficacy index: 1.0

• If a therapy has been beneficial then the PSE index after therapy should be close to 0 and the efficacy index should be closer to 1.0


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Specialty

Objective

ICD-10