Peripheral nerve injury

 

Vitalstatistix:

·         Nerve injury may become apparent days or even weeks later

·         Paraesthesia common: 15% of blocks. 99% resolve within 1 year.

·         Permanent injury rare (2.4 per 10k regional blocks) but often devastating

·         Ultrasound guidance does not seem to reduce incidence of nerve injury

 

Types of injury:

 

Description

Treatment

Prognosis

Neurapraxia

Myelin damaged

Nothing

Good

Axonotmesis

Axons transected

Maybe surgery

Depends if endoneurium cut

Neurotmesis

Whole nerve transected

Surgery

Poor

 

Most commonly injured nerves:

Ulnar nerve

·      Pressure

·      Stretch: elbow flexion

Brachial plexus

·      Compression

·      Stretch: shoulder abduction,posterior displacement, external rotation

·      Needle trauma

Lumbosacral nerve roots

·      Vaginal delivery with shoulder dystocia

Spinal cord

·      Neuraxial procedures

 

Cause of injury:

·         Needle trauma

·         Drug toxicity

·         Stretch

·         Compression

·         Tourniquet

·         Underlying disease

 

Approach to the patient with apparent nerve injury:

Open disclosure

·      I don’t yet know what the cause is, but it could be the local anaesthetic injection

·      I don’t yet know whether it’s going to get better

·      We will find all this out by examining the body part, getting tests, and getting an opinion from a specialist

History

·      Sensory disturbance (less vs more vs abnormal vs pain vs none)

·      Motor disturbance

·      Time course

Examination

·      Full neuro exam

·      Establish distribution of injury

Investigations

·      +/- NCS

·      +/- MRI

Referral

·      Neurologist