173.BLOCK AT NEUROMUSCULAR JUNCTION

A.FATIGUE
B.FASCICULATION
C.FLACCIDITY
D.

ANS:FLACCIDITY


A block or decrease in the transmission across the neuromuscular junction can cause a complete or relative loss of muscle function. It can result from neuromuscular junction diseases or be intentionally induced with neuromuscular blocking drugs. It can also be a side effect of other drugs that are generally not classified as neuromuscular blocking drugs, such as some anesthetic drugs

The degree of neuromuscular block may be estimated by Bromage score, which originally had four grades designate with the Roman numerals I until IV, but later complemented by Breen et al. with an inverse grading with Hindu-Arabic numerals:

Bromage score
       Grade                                         Criteria                                       Approximatedegree of block
IV              1       Complete block, inability to move feet or knees                                            100%
III              2       Almost complete block, ability to move feet only, with inability to flex knees     66%
II              3       Partial block, ability to flex knees                                                                     33%
                     4       Detectable weakness of hip flexion while supine, ability of full flexion of knees
                     5       No detectable weakness of hip flexion while supine
I              6       Free movement of legs and feet, ability to perform partial knee bend                 0%


In unconscious patients, such as during anesthesia, neural block can be assessed by a "train-of-four" by stimulating muscles from surface electrodes.