NSB Score of Kanikannan et al for Predicting Mechanical Ventilation in a Patient with Guillain-Barre Syndrome (GBS)

 

Patient selection: Guillain-Barre syndrome

 

Parameters for the NSB score:

(1) N = neck muscle weakness

(2) S = single breath count (SBC)

(3) B = bulbar weakness

 

The SBC is the number of numbers that the person can count in a normal speaking voice after a deep breath without taking another breath.

Parameter	Finding	Points
neck muscle weakness	absent	0
	present	40
SBC	< 19	20
	>= 19	0
bulbar weakness	absent	0
	present	40

 

total NSB =

= SUM(points for all 3 parameters)

 

Interpretation:

• minimum score: 0

• maximum score: 100

• A score >= 60 predicted the need for mechanical ventilation. This is equivalent to >= 2 parameters being present.

 

Performance:

• The sensitivity was 95% and specificity 93.5%.

 

Other findings associated with mechanical ventilation::

(1) forced vital capacity FVC < 15 mL/kg on admission

(2) increased phrenic nerve latency (associated with FVC)