Kanikannan et al developed a simple bedside score (the NSB score) for identifying a patient with Guillain-Barre syndrome (GBS) who requires mechanical ventilation. The authors are from Nizam’s Institute of Medical Sciences in Punjagutta, Hyderabdad, India.
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)
Specialty: Neurology, Immunology/Rheumatology, Infectious Diseases