PERIPHERAL NERVE BLOCKADE by jianglifang

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                                   PERIPHERAL	
  
                NERVE	
  BLOCKADE	
  

                                                                               	
  
                                           Is	
  ultrasound	
  the	
  new	
  black?	
  
                                                                               	
  
	
  




       THE	
  WORD	
  PAIN	
  ORIGINALLY	
  COMES	
  FROM	
  THE	
  GREEK	
  GODDESS	
  
       OF	
  REVENGE	
  “POINE”	
  WHO	
  WAS	
  SENT	
  TO	
  PUNISH	
  THE	
  INSOLENT	
  
       MORTALS	
  WHO	
  ENRAGED	
  THE	
  GODS.	
  IT	
  HAS	
  BEEN	
  DESCRIBED	
  BY	
  
        THE	
  INTERNATIONAL	
  ASSOCIATION	
  FOR	
  THE	
  STUDY	
  OF	
  PAIN	
  AS	
  
             "AN	
  UNPLEASANT	
  SENSORY	
  AND	
  EMOTIONAL	
  EXPERIENCE	
  
        ASSOCIATED	
  WITH	
  ACTUAL	
  OR	
  POTENTIAL	
  TISSUE	
  DAMAGE,	
  OR	
  
       DESCRIBED	
  IN	
  TERMS	
  OF	
  SUCH	
  DAMAGE”*.	
  	
  IT’S	
  TREATMENT	
  AND	
  
       MANAGEMENT	
  IS	
  ALSO	
  ONE	
  OF	
  THE	
  OLDEST	
  MEDICAL	
  PROBLEMS	
  
                                  KNOWN	
  TO	
  MANKIND.	
  

	
  

	
  



Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     1	
         10/8/2011	
     	
  
	
  


                                                          INTRODUCTION	
  

	
  
	
  
In	
  my	
  line	
  of	
  work	
  as	
  an	
  anaesthetic	
  technician	
  I	
  see	
  hundreds	
  of	
  patients	
  a	
  year	
  coming	
  
through	
  the	
  doors	
  of	
  our	
  operative	
  rooms.	
  We	
  give	
  each	
  and	
  every	
  one	
  of	
  these	
  patients	
  
an	
  anaesthetic	
  that,	
  to	
  the	
  untrained	
  eye,	
  may	
  look	
  the	
  same	
  but	
  in	
  reality	
  is	
  variable	
  and	
  
tailor	
  made	
  to	
  fit.	
  There	
  will	
  always	
  be	
  differences	
  in	
  each	
  patient’s	
  anaesthetic	
  dictated	
  
by	
  the	
  procedure,	
  the	
  patient’s	
  current	
  state	
  of	
  health	
  and	
  a	
  whole	
  other	
  myriad	
  of	
  
information	
  and	
  events.	
  	
  	
  These	
  differences	
  can	
  range	
  from	
  the	
  subtle	
  e.g.	
  the	
  amount	
  of	
  
a	
  particular	
  drug	
  given,	
  to	
  the	
  more	
  extreme	
  use	
  of	
  a	
  general	
  anaesthetic	
  Vs	
  a	
  regional	
  
anaesthetic	
  for	
  the	
  same,	
  or	
  similar,	
  operative	
  procedures.	
  	
  	
  
When	
  I	
  first	
  started	
  my	
  job	
  7	
  years	
  ago	
  this	
  difference	
  of	
  Regional	
  VS	
  General	
  perplexed	
  
and	
  intrigued	
  me.	
  I	
  didn’t	
  understand	
  if	
  all	
  surgery	
  could	
  be	
  performed	
  under	
  general	
  
anaesthetic	
  and	
  with	
  all	
  the	
  advances	
  in	
  analgesic	
  agents	
  why	
  we	
  would	
  bother	
  with	
  any	
  
other	
  kind.	
  	
  I	
  thought	
  that	
  regional	
  blockade	
  was	
  time	
  consuming	
  and	
  when	
  taken	
  in	
  
conjunction	
  with	
  its	
  risks,	
  of	
  little	
  benefit	
  to	
  the	
  patients	
  themselves,	
  I	
  just	
  didn’t	
  really	
  
see	
  the	
  point	
  of	
  it.	
  	
  

As	
  the	
  years	
  have	
  passed	
  by,	
  I	
  have	
  learnt	
  that	
  general	
  anaesthesia,	
  like	
  regional,	
  can	
  
have	
  its	
  advantages	
  and	
  disadvantages	
  and	
  may	
  in	
  fact	
  be	
  contra-­‐indicated	
  in	
  some	
  
patients.	
  I	
  came	
  to	
  see	
  that	
  in	
  the	
  right	
  hands	
  regional	
  anaesthesia	
  can	
  be	
  of	
  tremendous	
  
benefit	
  in	
  the	
  perioperative	
  environment.	
  	
  But	
  most	
  importantly	
  I	
  have	
  learnt	
  that	
  there	
  
is	
  a	
  definite	
  need	
  for	
  the	
  option	
  of	
  being	
  able	
  to	
  use	
  regional	
  blockade	
  intra	
  and	
  post	
  
operatively.	
  

When	
  I	
  decided	
  to	
  write	
  this	
  paper	
  it	
  seemed	
  only	
  natural	
  to	
  me	
  to	
  write	
  about	
  regional	
  
blockade.	
  I	
  wanted	
  to	
  understand	
  its	
  history,	
  look	
  back	
  and	
  see	
  it	
  evolve	
  into	
  what	
  we	
  
have	
  today.	
  I	
  wanted	
  to	
  see	
  the	
  years	
  of	
  research	
  in	
  developing	
  and	
  perfecting	
  
techniques	
  that	
  offered	
  the	
  best	
  and	
  safest	
  blocks.	
  I	
  thought	
  it	
  would	
  be	
  easy	
  that	
  there	
  
would	
  be	
  masses	
  of	
  published	
  research	
  and	
  articles	
  clearly	
  marking	
  the	
  way	
  throughout	
  
the	
  years	
  and	
  that	
  shared	
  a	
  similar	
  tale.	
  I	
  was	
  going	
  to	
  be	
  proven	
  wrong.	
  	
  	
  

The	
  information	
  out	
  there	
  is	
  often	
  fragmented	
  and	
  contradictory	
  to	
  one	
  another	
  and	
  is	
  
often	
  bias	
  to	
  support	
  the	
  author’s	
  beliefs.	
  For	
  every	
  opinion	
  there	
  is	
  an	
  article	
  quoting	
  a	
  
study	
  to	
  support	
  it.	
  So	
  I	
  read	
  countless	
  articles	
  and	
  made	
  some	
  surprising	
  discoveries	
  
that	
  changed	
  the	
  course	
  of	
  my	
  paper.	
  I	
  really	
  wanted	
  to	
  know	
  where	
  it	
  had	
  all	
  begun.	
  
What	
  does	
  the	
  future	
  have	
  in	
  store?	
  And	
  are	
  we	
  too	
  easy	
  to	
  persuade	
  to	
  adopt	
  new	
  
techniques	
  such	
  as	
  the	
  use	
  of	
  ultrasound	
  based	
  primarily	
  on	
  hype	
  and	
  perhaps	
  on	
  
misleading	
  information?	
  	
  	
  

	
  

	
  


                                                                               	
  

                                                                               	
  

	
  



Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     2	
                                                10/8/2011	
      	
  
	
  


                                     REGIONAL	
  -­‐	
  WHY	
  DO	
  WE	
  CARE?	
  

	
  
	
  
From	
  the	
  first	
  use	
  of	
  an	
  “analgesic”	
  agent	
  (opium	
  in	
  the	
  Neolithic	
  age)	
  people	
  have	
  
known	
  of	
  the	
  enormous	
  benefits	
  of	
  opioids	
  for	
  pain	
  relief.	
  There	
  have	
  been	
  many	
  hours	
  
devoted	
  to	
  the	
  research	
  of	
  creating	
  synthetic	
  versions	
  that	
  offer	
  better	
  relief	
  of	
  pain	
  with	
  
fewer	
  side	
  effects.	
  	
  With	
  the	
  introduction	
  of	
  various	
  synthetics	
  with	
  different	
  
pharmacokinetic	
  and	
  pharmacodynamics	
  profiles	
  we	
  are	
  able	
  to,	
  in	
  most	
  cases,	
  offer	
  and	
  
use	
  an	
  analgesic	
  agent	
  that	
  will	
  suit	
  the	
  patient,	
  the	
  operative	
  requirements,	
  and	
  yet	
  still	
  
be	
  cost	
  effective.	
  	
  
With	
  all	
  of	
  the	
  advancements	
  in	
  this	
  area,	
  postoperative	
  pain	
  and	
  the	
  side	
  effects	
  
associated	
  with	
  general	
  anaesthesia	
  and	
  opioids	
  i.e.	
  Post	
  Operative	
  Nausea	
  and	
  Vomiting	
  
(PONV),	
  still	
  ranks	
  as	
  one	
  of	
  the	
  top	
  concerns	
  of	
  patients	
  in	
  the	
  peri	
  operative	
  
environment,	
  and	
  there	
  may	
  be	
  good	
  reason	
  for	
  this.	
  	
  	
  
Recent	
  evidence	
  suggests	
  that	
  post	
  operative	
  pain	
  continues	
  to	
  be	
  poorly	
  managed	
  with	
  
a	
  high	
  proportion	
  of	
  patients	
  still	
  experiencing	
  pain	
  that	
  is	
  described	
  as	
  extreme.	
  Even	
  
with	
  the	
  best	
  anti	
  emetics	
  on	
  board,	
  PONV	
  can	
  still	
  be	
  a	
  likely	
  side	
  effect	
  from	
  opioids	
  
use.	
  	
  For	
  some	
  patients,	
  there	
  is	
  little	
  that	
  can	
  be	
  done	
  to	
  stop	
  PONV	
  following	
  a	
  general	
  
anaesthetic*1.	
  	
  
The	
  effects	
  that	
  pain	
  and	
  PONV	
  can	
  have	
  on	
  recovery	
  times	
  should	
  not	
  be	
  
underestimated*2.	
  	
  In	
  this	
  day	
  and	
  age	
  of	
  consumer	
  domination,	
  patients	
  have	
  an	
  
expectation	
  of	
  surgery	
  being	
  designer	
  and	
  catered	
  to	
  meet	
  there	
  wants	
  and	
  needs.	
  This	
  
often	
  includes	
  an	
  expectation	
  of	
  little	
  to	
  no	
  pain	
  or	
  discomfort,	
  no	
  PONV	
  and	
  a	
  quick	
  
recovery	
  time,	
  that	
  has	
  the	
  least	
  amount	
  of	
  impact	
  on	
  their	
  busy	
  schedules.	
  People	
  lead	
  
faster	
  fuller	
  lives	
  and	
  don’t	
  want,	
  or	
  have,	
  the	
  time	
  for	
  extended	
  hospital	
  stays.	
  If	
  their	
  
needs	
  and	
  wants	
  are	
  not	
  meet,	
  it	
  can	
  lead	
  to	
  feelings	
  of	
  dissatisfaction,	
  disappointment	
  
and	
  a	
  fear	
  of	
  future	
  or	
  further	
  surgeries.	
  	
  	
  
So	
  the	
  medical	
  fields	
  have	
  looked	
  for	
  other	
  solutions	
  to	
  these	
  problems	
  and	
  have	
  found	
  
some	
  suitable	
  alternatives	
  to	
  the	
  use	
  of	
  general	
  anaesthetic	
  and	
  the	
  use	
  of	
  opioids	
  as	
  the	
  
primary	
  drug	
  for	
  pain	
  relief.	
  	
  
One	
  such	
  alternative	
  is	
  the	
  development	
  and	
  use	
  of	
  local	
  anaesthetic’s,	
  first	
  topically,	
  
then	
  by	
  means	
  of	
  local	
  infiltration	
  and	
  then	
  finally	
  with	
  regional	
  blockade.	
  	
  	
  Although	
  we	
  
have	
  known	
  of	
  the	
  benefits	
  of	
  local	
  anaesthetics	
  for	
  some	
  time,	
  it	
  has	
  only	
  been	
  in	
  recent	
  
times	
  that	
  its	
  use	
  in	
  regional	
  blockade	
  has	
  been	
  considered	
  a	
  serious	
  alternative	
  to	
  
general	
  anaesthetic	
  and	
  intravenous	
  opioids	
  in	
  the	
  peri	
  operative	
  environment.	
  	
  	
  
So	
  why	
  has	
  it	
  taken	
  so	
  long	
  for	
  us	
  to	
  except	
  regional	
  with	
  such	
  open	
  arms?	
  I	
  think	
  
because	
  in	
  the	
  past	
  we	
  haven’t	
  needed	
  or	
  wanted	
  too.	
  Regional	
  anaesthesia	
  was	
  
considered	
  to	
  be	
  impractical,	
  time	
  consuming	
  and	
  dangerous	
  for	
  the	
  patient	
  when	
  in	
  the	
  
wrong	
  or	
  inexperienced	
  hands.	
  General	
  anaesthesia	
  was	
  easier	
  to	
  achieve,	
  covered	
  all	
  
surgeries	
  and	
  took	
  less	
  time	
  to	
  master	
  than	
  regional,	
  so	
  for	
  the	
  most	
  part	
  there	
  has	
  been	
  
insufficient	
  motivation	
  to	
  change	
  this.	
  	
  	
  
Times	
  have	
  changed.	
  We	
  can	
  do	
  more	
  for	
  people	
  surgically	
  and,	
  patients	
  themselves	
  
have	
  different	
  expectations	
  of	
  their	
  surgical	
  experience.	
  We	
  have	
  had	
  to	
  come	
  up	
  with	
  
ways	
  to	
  meet	
  both	
  the	
  advancements	
  in	
  surgery	
  and	
  the	
  patient’s	
  needs	
  to	
  find	
  a	
  
practical,	
  safe	
  and	
  cost	
  effective	
  balance	
  between	
  the	
  two.	
  And	
  regional	
  anaesthesia	
  
seems	
  to	
  be	
  doing	
  just	
  that.	
  	
  But	
  to	
  understand	
  this	
  fully	
  we	
  need	
  to	
  go	
  right	
  back	
  to	
  the	
  
start	
  and	
  take	
  a	
  look	
  at	
  the	
  evolution	
  of	
  regional	
  anaesthesia.	
  	
  	
  
	
  


                                                                               	
  


Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     3	
                                                       10/8/2011	
       	
  
	
  


                                                                   HISTORY	
  

	
  
	
  
Throughout	
  history	
  there	
  have	
  been	
  many	
  potions	
  and	
  concoctions	
  (mostly	
  using	
  opium	
  
or	
  a	
  variety	
  of	
  solanum	
  species)*3	
  that	
  have	
  aided	
  in	
  producing	
  a	
  “stupor”	
  like	
  effect.	
  It	
  
wasn’t	
  until	
  the	
  discovery	
  of	
  nitrous	
  oxide,	
  by	
  Joseph	
  Priestly	
  that	
  an	
  evolution	
  in	
  
anaesthesia	
  began	
  to	
  take	
  place.	
  	
  
The	
  discovery	
  of	
  nitrous	
  oxide	
  occurred	
  at	
  the	
  end	
  of	
  the	
  18th	
  century	
  and	
  then	
  ,	
  early	
  in	
  
the	
  19th	
  century	
  a	
  chemist,	
  Humphrey	
  Davy,	
  conducted	
  some	
  ‘physiological’	
  
experiments	
  with	
  the	
  gas	
  and	
  discovered	
  that	
  after	
  taking	
  deep	
  breathes	
  over	
  a	
  brief	
  
period	
  of	
  time	
  it	
  would	
  produce	
  a	
  feeling	
  of	
  intoxication*4.	
  	
  This	
  paved	
  the	
  way	
  for	
  its	
  
future	
  use.	
  	
  
The	
  relevance	
  of	
  Nitrous	
  Oxide	
  to	
  anaesthesia	
  occurred 45	
  years	
  later,	
  in	
  1844,	
  when	
  it	
  
was	
  used	
  as	
  an	
  anaesthetic	
  by	
  Gardner	
  Colton,	
  a	
  travelling	
  scientist,	
  and	
  Horace	
  Wells,	
  a	
  
practicing	
  dentist.	
  Colton	
  gave	
  the	
  nitrous	
  oxide	
  to	
  Wells,	
  whose	
  dental	
  partner	
  then	
  
extracted	
  his	
  wisdom	
  teeth	
  without	
  causing	
  pain*5.	
  Wells	
  would	
  go	
  on	
  to	
  use	
  this	
  
technique	
  for	
  many	
  other	
  successful	
  wisdom	
  teeth	
  extractions.	
  	
  
Many	
  years	
  later	
  he	
  would	
  enter	
  into	
  a	
  business	
  partnership	
  with	
  a	
  man	
  named	
  William	
  
Morton.	
  This	
  business,	
  a	
  dental	
  Practice,	
  would	
  eventually	
  fail	
  and	
  Wells	
  and	
  Morton	
  
would	
  go	
  their	
  separate	
  ways.	
  Wells	
  would	
  go	
  to	
  work	
  at	
  another	
  dental	
  practice	
  and	
  
Morton	
  would	
  go	
  on	
  to	
  study	
  at	
  the	
  Boston	
  Medical	
  School.	
  Whilst	
  there,	
  Morton,	
  under	
  
the	
  guidance	
  of	
  Charles	
  Jackson,	
  would	
  study	
  the	
  properties	
  of	
  the	
  Gas	
  Ether.	
  This	
  would	
  
prove	
  invaluable	
  later	
  in	
  his	
  life.	
  	
  
After	
  suffering	
  a	
  breakdown,	
  that	
  led	
  him	
  to	
  drop	
  out	
  of	
  medical	
  school,	
  Morton	
  would	
  
reunite	
  with	
  Wells	
  once	
  more.	
  After	
  witnessing	
  a	
  dental	
  extraction	
  under	
  nitrous	
  oxide,	
  
that	
  was	
  anything	
  but	
  painless,	
  Morton	
  decided	
  to	
  leave	
  and	
  open	
  his	
  own	
  dental	
  
practice	
  specializing	
  in	
  false	
  teeth.	
  	
  	
  
After	
  witnessing	
  the	
  painful	
  dental	
  extraction	
  with	
  the	
  use	
  of	
  nitrous	
  oxide,	
  he	
  decided	
  
to	
  experiment	
  with	
  a	
  gas	
  he	
  was	
  familiar	
  with	
  and	
  on	
  30th	
  of	
  September	
  he	
  used	
  this	
  gas,	
  
ether,	
  on	
  a	
  patient	
  to	
  extract	
  his	
  wisdom	
  teeth.	
  It	
  was	
  such	
  a	
  success	
  that	
  Morton,	
  after	
  
being	
  contacted	
  by	
  a	
  young	
  surgeon	
  named	
  Henry	
  Bigelow,	
  decided	
  to	
  hold	
  a	
  public	
  
demonstration.	
  	
  This	
  was	
  the	
  first	
  demonstration	
  of	
  a	
  general	
  anaesthetic	
  and	
  it	
  took	
  
place	
  on	
  October	
  16	
  1846*5.	
  
The	
  “cocaine”	
  alkaloid	
  was	
  first	
  isolated	
  in1855	
  by	
  German	
  chemist	
  Friedrich	
  Gaedcke.	
  
He	
  named	
  this	
  substance	
  erythroxyline.	
  Then,	
  4	
  years	
  later,	
  P.H.	
  D	
  student	
  Albert	
  
Niemann	
  devised	
  a	
  simpler	
  purification	
  process	
  and	
  named	
  the	
  substance	
  produced	
  
cocaine*6.	
  	
  Cocaine	
  was	
  deemed	
  to	
  be	
  too	
  addictive	
  and	
  toxic.	
  This	
  would	
  lead	
  to	
  the	
  
development	
  in	
  the	
  preceding	
  years	
  of	
  many	
  other	
  forms	
  of	
  local	
  anaesthetics	
  such	
  as	
  
stovaine,	
  procaine	
  and	
  amethocaine*7.	
  
	
  	
  	
  	
  The	
  first	
  description	
  of	
  the	
  use	
  of	
  a	
  local	
  anaesthetic	
  was	
  in1884.	
  Carl	
  Koller	
  used	
  
topical	
  cocaine	
  as	
  a	
  drop	
  to	
  anaesthetize	
  his	
  eye	
  and	
  then	
  described	
  being	
  able	
  to	
  prick	
  it	
  
with	
  pins	
  and	
  feel	
  no	
  pain*8.	
  This	
  was	
  followed	
  the	
  next	
  year	
  by	
  the	
  first	
  brachial	
  plexus	
  
block	
  which	
  was	
  performed	
  by	
  surgeons	
  William	
  Halstead	
  and	
  Richard	
  Hall.	
  It	
  was	
  done	
  
under	
  direct	
  vision,	
  using	
  cocaine	
  injected	
  into	
  the	
  nerve	
  trunks	
  during	
  surgical	
  
procedures*9.	
  	
  This	
  milestone	
  would	
  pave	
  the	
  way	
  for	
  advancements	
  in	
  regional	
  
anaesthesia	
  for	
  decades	
  to	
  come.	
  
	
  


                                                                               	
  



Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     4	
                                                  10/8/2011	
       	
  
	
  


	
  

	
  
	
  
In	
  1898,	
  August	
  Bier	
  described	
  the	
  first	
  use	
  of	
  spinal	
  anaesthesia	
  for	
  lower	
  limb	
  surgery.	
  
10	
  years	
  later	
  in	
  1908	
  he	
  would	
  be	
  the	
  first	
  to	
  use	
  intravenous	
  regional	
  anaesthesia.	
  He	
  
was	
  able	
  to	
  induce	
  complete	
  anaesthesia	
  and	
  motor	
  blockade	
  after	
  injecting	
  procaine	
  
into	
  a	
  vein	
  after	
  the	
  exsanguination	
  of	
  the	
  arm*10.	
  	
  A	
  few	
  years	
  later,	
  	
  Hirschel	
  and	
  
Kulenkampff	
  	
  would	
  describe	
  the	
  first	
  percutaneous	
  brachial	
  plexus	
  block	
  using	
  the	
  
axillary	
  approach	
  first,	
  then	
  later	
  using	
  the	
  supraclavicular	
  method*11.	
  	
  	
  
The	
  development	
  of	
  regional	
  anaesthesia	
  seemed	
  to	
  be	
  progressing	
  quickly	
  and	
  more	
  
interest	
  was	
  being	
  generated	
  with	
  new	
  approaches	
  being	
  trialed	
  to	
  varying	
  degrees	
  of	
  
success.	
  Unfortunately	
  with	
  the	
  introduction	
  in	
  the	
  1930s-­‐40s	
  of	
  new	
  anaesthetic	
  agents	
  
such	
  as	
  thiopentone	
  and	
  muscle	
  relaxants*12,	
  together	
  with	
  the	
  highly	
  publicized	
  trial	
  of	
  
Albert	
  Woolley	
  and	
  Cecil	
  Roe	
  (two	
  men	
  left	
  as	
  paraplegics	
  after	
  receiving	
  spinal	
  
anaesthesia	
  for	
  minor	
  operative	
  procedures*13)	
  enthusiasm	
  for	
  regional	
  blockade	
  
diminished	
  and	
  its	
  development	
  was	
  too	
  stagnant	
  for	
  many	
  years.	
  
	
  In	
  1978	
  La	
  Grange,	
  a	
  prominent	
  doctor	
  at	
  the	
  time	
  described	
  the	
  use	
  of	
  an	
  ultrasound	
  
Doppler	
  device	
  to	
  identify	
  the	
  subclavian	
  artery	
  and	
  vein	
  when	
  doing	
  supraclavicular	
  
blocks.	
  With	
  this	
  technique	
  he	
  had	
  a	
  reported	
  98%	
  success	
  rate	
  with	
  no	
  complications*14.	
  
Although	
  the	
  results	
  were	
  very	
  promising	
  this	
  method,	
  for	
  the	
  time	
  being	
  ,would	
  prove	
  
to	
  be	
  impractical	
  in	
  the	
  everyday	
  setting	
  as	
  ultrasound	
  Doppler’s	
  were	
  cumbersome	
  and	
  
expensive.	
  	
  
In	
  the	
  early	
  1990s	
  a	
  few	
  articles	
  would	
  be	
  published	
  demonstrating	
  the	
  use	
  of	
  
ultrasound	
  in	
  identification	
  of	
  anatomical	
  structures	
  and	
  for	
  visualization	
  of	
  local	
  spread	
  
on	
  injection.	
  	
  This	
  had	
  the	
  potential	
  to	
  minimize	
  the	
  amount	
  of	
  local	
  used	
  for	
  maximum	
  
results*15.	
  But	
  any	
  interest	
  that	
  was	
  generated	
  by	
  the	
  promise	
  these	
  articles	
  showed	
  was	
  
about	
  to	
  be	
  directed	
  elsewhere	
  because	
  at	
  the	
  same	
  time	
  there	
  were	
  many	
  high	
  profile	
  
articles*16	
  being	
  published	
  that	
  were	
  proving	
  that	
  regional	
  anaesthesia	
  could,	
  in	
  the	
  
right	
  hands,	
  indeed	
  be	
  safe	
  and	
  these	
  articles	
  were	
  primarily	
  based	
  around	
  the	
  use	
  of	
  a	
  
device	
  that	
  was	
  coming	
  of	
  age	
  the	
  peripheral	
  nerve	
  stimulator.	
  	
  In	
  1912,	
  the	
  first	
  
description	
  of	
  the	
  use	
  of	
  a	
  nerve	
  stimulator	
  was	
  documented.	
  Georg	
  Perthes,	
  a	
  surgeon	
  
from	
  Tubingen	
  Germany,	
  described	
  his	
  experiences	
  after	
  experimentation	
  with	
  nerve	
  
stimulation	
  using	
  an	
  induction	
  apparatus	
  and	
  a	
  nickel	
  needle	
  painted	
  to	
  the	
  tip	
  with	
  a	
  
lacquer	
  substance*17.	
  	
  By	
  1962	
  Greenblatt	
  had	
  devised	
  a	
  more	
  portable	
  purpose	
  built	
  
nerve	
  stimulator	
  and	
  had	
  documented	
  his	
  findings	
  and	
  was	
  working	
  on	
  perfecting	
  his	
  
technique*18.	
  But	
  this	
  kind	
  of	
  device	
  would	
  prove	
  to	
  be	
  too	
  costly	
  for	
  mass	
  production	
  in	
  
an	
  area	
  of	
  anaesthesia	
  that	
  was	
  still	
  in	
  its	
  infancy.	
  In	
  1969	
  Ballard	
  D.	
  Wright	
  would	
  
modify	
  the	
  already	
  commercially	
  available	
  Block-­‐Aid	
  monitor	
  (an	
  external	
  
neuromuscular	
  stimulator)*19.	
  This	
  would	
  prove	
  invaluable	
  as	
  it	
  would	
  enable	
  more	
  
people	
  to	
  perform	
  blocks	
  and	
  research	
  the	
  area	
  than	
  would	
  otherwise	
  have	
  been	
  
possible.	
  	
  

	
  

	
  

	
  

	
  


	
  

Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     5	
                                           10/8/2011	
      	
  
	
  


PARAESTHESIAE,	
  NERVE	
  STIMULATION	
  AND	
  ULTRASOUND	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  

	
  

	
  In	
  1980	
  the	
  gold	
  standard	
  for	
  regional	
  blockade	
  in	
  NZ	
  was	
  parasthesia.	
  This	
  relied	
  on	
  a	
  
complete	
  knowledge	
  of	
  anatomical	
  structures,	
  experience,	
  feel	
  and	
  total	
  cooperation	
  
from	
  the	
  patient.	
  After	
  assessing	
  the	
  appropriate	
  anatomy,	
  and	
  feeling	
  for	
  a	
  pulse,	
  a	
  
needle	
  would	
  be	
  inserted	
  at	
  the	
  angle	
  and	
  to	
  the	
  depth	
  the	
  doctor	
  felt	
  necessary.	
  	
  After	
  
elicitation	
  of	
  “appropriate”	
  parasthesia	
  he	
  would	
  aspirate	
  and	
  inject.	
  	
  	
  It	
  had	
  a	
  reported	
  
success	
  rate	
  of	
  between	
  82%	
  and	
  95%	
  and	
  had	
  reported	
  complications	
  rate	
  of	
  approx	
  
0.36%*20.Then	
  in	
  the	
  late	
  80s	
  an	
  article	
  was	
  published	
  in	
  The	
  American	
  Society	
  of	
  
Regional	
  Anesthesia	
  It	
  was	
  entitled	
  Use	
  of	
  the	
  Nerve	
  Stimulator	
  for	
  Peripheral	
  Blocks	
  	
  by	
  
P.	
  Prithvi	
  Raj,	
  MD,	
  Richard	
  Rosenblatt,	
  MD,	
  S.J.	
  Montgomery,	
  MD.	
  This	
  detailed	
  the	
  use	
  of	
  
a	
  nerve	
  stimulator	
  for	
  locating	
  the	
  nerve	
  and,	
  although	
  not	
  a	
  new	
  invention,	
  this	
  was	
  one	
  
of	
  the	
  first	
  articles	
  that	
  showed	
  there	
  might	
  be	
  enormous	
  benefit	
  in	
  the	
  use	
  of	
  nerve	
  
stimulators	
  in	
  assisting	
  with	
  peripheral	
  nerve	
  blocks.	
  The	
  article	
  was	
  based	
  on	
  the	
  
findings	
  of	
  years	
  of	
  research	
  by	
  the	
  authors.	
  They	
  had	
  experimented	
  with	
  stimulation	
  
using	
  unsheathed	
  needles,	
  minimum	
  voltage	
  required	
  and	
  what	
  voltage	
  produced	
  a	
  
twitch	
  that	
  was	
  sufficient	
  for	
  a	
  successful	
  block	
  without	
  being	
  in	
  the	
  nerve	
  itself.	
  They	
  
also	
  looked	
  at	
  what	
  characteristics	
  were	
  desirable	
  in	
  a	
  nerve	
  stimulator	
  and	
  gave	
  their	
  
thoughts	
  on	
  the	
  stimulators	
  that	
  were	
  available	
  on	
  the	
  market	
  at	
  the	
  time	
  detailed	
  
explanations	
  were	
  documented	
  on	
  the	
  different	
  blocks	
  and	
  how	
  they	
  were	
  best	
  
achieved.	
  This	
  would	
  spearhead	
  the	
  use	
  of	
  a	
  nerve	
  stimulator	
  in	
  regional	
  blockade	
  and	
  
lead	
  to	
  more	
  research	
  and	
  published	
  papers	
  on	
  the	
  use	
  of	
  nerve	
  stimulators.	
  	
  But	
  did	
  the	
  
everyday	
  introduction	
  of	
  nerve	
  stimulators	
  actually	
  bring	
  anything	
  of	
  benefit	
  to	
  regional	
  
anaesthesia?	
  Or	
  was	
  it	
  just	
  new	
  and	
  exciting?	
  	
  

To	
  answer	
  these	
  questions	
  we	
  must	
  first	
  look	
  at	
  what	
  we	
  want	
  to	
  achieve	
  and	
  what	
  is	
  
desirable	
  in	
  regional	
  blockade.	
  	
  

Firstly	
  you	
  want	
  a	
  technique	
  that	
  is	
  as	
  non-­‐invasive	
  as	
  possible.	
  You	
  want	
  the	
  ability	
  to	
  
be	
  able	
  to	
  distribute	
  the	
  local	
  anaesthetic	
  close	
  to	
  the	
  desired	
  nerve	
  without	
  causing	
  
damage.	
  Be	
  able	
  to	
  use	
  as	
  little	
  local	
  anaesthetic	
  as	
  possible.	
  It	
  must	
  have	
  a	
  high	
  success	
  
rate,	
  be	
  cost,	
  and	
  time,	
  effective;	
  provide	
  excellent	
  pain	
  relief	
  and	
  most	
  importantly	
  it	
  
has	
  to	
  be	
  safe.	
  So	
  does	
  the	
  peripheral	
  nerve	
  stimulator	
  improve	
  these	
  things?	
  On	
  the	
  
surface	
  the	
  answer	
  might	
  seem	
  clear.	
  I	
  think	
  the	
  answer	
  is	
  yes	
  and	
  no.	
  In	
  the	
  
experienced	
  hand	
  there	
  has	
  been	
  little	
  to	
  no	
  evidence	
  to	
  suggest	
  that	
  it	
  improves	
  
complication	
  rates*21.	
  	
  There	
  has	
  been	
  no	
  published	
  research	
  that	
  shows	
  a	
  significant	
  
drop	
  in	
  the	
  amount	
  of	
  local	
  needed.	
  You	
  had	
  to	
  purchase	
  and	
  maintain	
  the	
  nerve	
  
stimulator(s)	
  and	
  use	
  specialized	
  needles.	
  Without	
  the	
  offset	
  of	
  the	
  need	
  for	
  less	
  local	
  it	
  
may	
  in	
  fact	
  cost	
  more.	
  There	
  has	
  been	
  little	
  evidence	
  to	
  suggest	
  that,	
  in	
  experienced	
  
hands,	
  it	
  improved	
  the	
  time	
  taken	
  to	
  complete	
  the	
  block	
  or	
  the	
  onset	
  time	
  to	
  successful	
  
blockade.*22	
  But,	
  like	
  I	
  said,	
  that’s	
  on	
  the	
  surface.	
  If	
  we	
  look	
  a	
  little	
  deeper	
  and	
  take	
  into	
  
account	
  factors	
  like	
  parasthesia	
  being	
  subjective	
  and	
  is	
  judged	
  solely	
  on	
  the	
  information	
  
being	
  relayed	
  from	
  the	
  patient.	
  This	
  can	
  be	
  inconsistent,	
  and	
  even	
  inaccurate,	
  as	
  things	
  
like	
  anxiety	
  and	
  pain	
  from	
  injury	
  can	
  alter	
  their	
  perceptions.	
  	
  

	
  

	
  


                                                                               	
  


Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     6	
                                                      10/8/2011	
      	
  
	
  


                                                                               	
  

	
  
	
  
It	
  relied	
  on	
  the	
  anatomical	
  knowledge	
  and	
  experience	
  of	
  the	
  person	
  performing	
  the	
  
regional	
  block.	
  Results	
  could	
  be	
  variable	
  in	
  the	
  inexperienced	
  hands.	
  Also	
  it	
  could	
  not	
  be	
  
performed	
  in	
  certain	
  people	
  such	
  as	
  the	
  disabled,	
  demented	
  and	
  some	
  general	
  groups	
  
such	
  as	
  pediatrics	
  or	
  people	
  of	
  a	
  different	
  language	
  as,	
  even	
  with	
  the	
  aid	
  of	
  an	
  
interpreter,	
  this	
  would	
  prove	
  difficult.	
  It	
  also	
  cannot	
  be	
  performed	
  after	
  the	
  patient	
  has	
  
had	
  a	
  sedative	
  or	
  been	
  placed	
  under	
  general	
  anaesthesia	
  as	
  the	
  patient	
  could	
  not	
  state	
  
when	
  parasthesia	
  was	
  felt.	
  It	
  is	
  harder	
  to	
  teach	
  and	
  learn	
  as	
  it	
  relies	
  on	
  experience	
  and	
  
feel	
  and	
  an	
  understanding	
  of	
  patient	
  reactions.	
  Additionally,	
  there	
  is	
  no	
  reliable	
  
indicator	
  for	
  the	
  person	
  teaching	
  that	
  the	
  person	
  learning	
  is	
  in	
  the	
  right	
  area.	
  These	
  are	
  
things	
  that	
  the	
  nerve	
  stimulators	
  looked	
  to	
  improve	
  and	
  were	
  therefore	
  able	
  to	
  offer	
  that	
  
parasthesia	
  could	
  not.	
  Although	
  these	
  things	
  may	
  not	
  have	
  any	
  effect	
  on	
  the	
  outcome	
  of	
  
the	
  actual	
  block	
  itself	
  they	
  allowed	
  doctors	
  to	
  be	
  able	
  to	
  offer	
  more	
  people	
  regional	
  
blockade.	
  There	
  is	
  no	
  conclusive	
  study	
  that	
  proves	
  that	
  the	
  success	
  rate	
  is	
  higher	
  with	
  
the	
  use	
  of	
  nerve	
  stimulators	
  but	
  most	
  people	
  would	
  agree	
  that	
  the	
  majority	
  of	
  studies	
  
that	
  have	
  been	
  done	
  do	
  suggest	
  that	
  there	
  is	
  a	
  slight	
  advantage	
  in	
  its	
  use.	
  This	
  leads	
  to	
  a	
  
better	
  chance	
  of	
  a	
  complete	
  block	
  and	
  therefore	
  excellent	
  pain	
  relief	
  being	
  achieved	
  
more	
  often	
  bringing	
  more	
  confidence	
  to	
  the	
  game	
  both	
  for	
  the	
  doctor	
  and	
  for	
  the	
  
patients	
  themselves.	
  	
  	
  
However	
  nerve	
  stimulators	
  do	
  have	
  their	
  own	
  draw	
  backs.	
  It	
  can	
  often	
  be	
  uncomfortable	
  
and	
  sore	
  for	
  the	
  patient	
  as	
  it	
  elicits	
  a	
  twitch	
  in	
  an	
  already	
  sore,	
  injured	
  limb.	
  This	
  can,	
  if	
  
prolonged,	
  be	
  very	
  upsetting	
  and	
  lead	
  to	
  the	
  patient	
  getting	
  distressed	
  and	
  becoming	
  
uncooperative.	
  It	
  still	
  relies	
  on	
  the	
  skill	
  of	
  the	
  doctor	
  but	
  he	
  may	
  overlook	
  or	
  ignore	
  
signs	
  he	
  is	
  too	
  close	
  or	
  in	
  the	
  nerve	
  if	
  the	
  nerve	
  stimulator	
  is”	
  telling”	
  him	
  otherwise,	
  
especially	
  while	
  he	
  is	
  learning	
  the	
  technique	
  or	
  if	
  the	
  patient	
  is	
  sedated.	
  It	
  can	
  be	
  
preformed	
  while	
  the	
  patient	
  is	
  sedated	
  or	
  under	
  general	
  anaesthesia.	
  This	
  has	
  the	
  
potential	
  to	
  lead	
  to	
  high	
  instances	
  of	
  nerve	
  damage	
  as	
  the	
  patient	
  may/would	
  be	
  unable	
  
to	
  indicate	
  paraesthesiae.	
  The	
  common	
  place	
  use	
  of	
  the	
  nerve	
  stimulator	
  may	
  not	
  have	
  
been	
  a	
  “giant	
  leap	
  for	
  mankind”,	
  it	
  has,	
  at	
  the	
  very	
  least,	
  enabled	
  many	
  more	
  people	
  to	
  
learn	
  the	
  technique	
  and	
  become	
  proficient	
  at	
  regional	
  anaesthesia	
  than	
  would	
  otherwise	
  
have	
  been	
  possible.	
  	
  This	
  of	
  course	
  leads	
  to	
  more	
  interest	
  in	
  the	
  area	
  which	
  leads	
  to	
  
more	
  research	
  to	
  make	
  better	
  equipment,	
  which	
  then	
  requires	
  more	
  companies	
  to	
  
produce	
  nerve	
  stimulators	
  and	
  needles	
  which	
  makes	
  the	
  market	
  more	
  competitive	
  
hence	
  cheaper	
  and	
  with	
  better	
  more	
  appropriate	
  equipment.	
  This	
  can	
  only	
  be	
  a	
  good	
  
thing	
  because	
  all	
  the	
  interest	
  that	
  it	
  generated,	
  even	
  in	
  debate,	
  brought	
  attention	
  to	
  
regional	
  blockade	
  and	
  showed	
  that	
  it	
  was	
  safe	
  when	
  in	
  the	
  right	
  hands,	
  that	
  it	
  could	
  have	
  
tremendous	
  benefits	
  for	
  patients	
  and	
  that	
  it	
  fully	
  deserved	
  a	
  place	
  in	
  the	
  peri	
  operative	
  
setting.	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  	
  

	
  

	
  

	
  


                                                                               	
  

	
  


Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     7	
                                                       10/8/2011	
        	
  
	
  


                                                                               	
  

	
  

In	
  2010	
  the	
  gold	
  standard	
  for	
  regional	
  blockade	
  involves	
  the	
  use	
  of	
  an	
  ultrasound	
  
machine.	
  The	
  machine	
  is	
  used	
  to	
  visualize	
  the	
  nerves	
  and	
  their	
  surrounding	
  structures	
  
and	
  enables	
  the	
  visualization	
  of	
  local	
  spread.	
  But,	
  like	
  its	
  predecessor	
  the	
  nerve	
  
stimulator,	
  it	
  brings	
  up	
  the	
  debate	
  of	
  whether	
  it	
  actually	
  offers	
  anything	
  of	
  significant	
  
value	
  to	
  regional	
  blockade.	
  	
  
If	
  it	
  is	
  as	
  good	
  as	
  some	
  believe	
  then	
  why,	
  like	
  the	
  nerve	
  stimulator,	
  has	
  it	
  taken	
  so	
  long	
  to	
  
develop?	
  	
  The	
  answer	
  might	
  be	
  easier	
  than	
  you	
  think.	
  	
  It	
  has	
  taken	
  this	
  long	
  for	
  
technology	
  to	
  catch	
  up	
  with	
  intention.	
  	
  
We	
  have	
  known	
  that	
  ultrasound	
  could	
  be	
  of	
  benefit	
  with	
  regional	
  blockade	
  for	
  decades.	
  
It	
  has	
  only	
  been	
  recent	
  advancements	
  in	
  ultrasound	
  technology	
  that	
  have	
  allowed	
  it	
  to	
  
be	
  fully	
  explored	
  and	
  its	
  potential	
  realized.	
  	
  
Machines	
  have	
  become	
  smaller	
  and	
  more	
  portable.	
  They	
  have	
  improved	
  software	
  which	
  
enables	
  better	
  imaging.	
  	
  They	
  have	
  different	
  probes	
  for	
  different	
  needs	
  and	
  various	
  
functions	
  such	
  as	
  coloured	
  Doppler	
  and	
  the	
  ability	
  to	
  adjust	
  gain	
  and	
  depth.	
  They	
  are	
  
also	
  cheaper	
  than	
  in	
  previous	
  years	
  and	
  can	
  offer	
  assistance	
  in	
  other	
  procedures	
  such	
  as	
  
intravenous	
  luer	
  and	
  central	
  line	
  placement,	
  Due	
  to	
  their	
  portability,	
  they	
  can	
  be	
  shared	
  
by	
  different	
  areas	
  in	
  the	
  hospital.	
  This	
  can	
  make	
  the	
  initial	
  cost	
  more	
  palatable	
  and	
  
makes	
  for	
  better	
  cost	
  effectiveness.	
  	
  	
  	
  
When	
  the	
  nerve	
  stimulator	
  was	
  rearing	
  its	
  head,	
  it	
  had	
  not	
  only	
  to	
  compete	
  with	
  the	
  
tried	
  and	
  true	
  method	
  of	
  paraesthesiae	
  and	
  its	
  devout	
  followers	
  it	
  had	
  to	
  also,	
  in	
  some	
  
ways,	
  prove	
  that	
  regional	
  was	
  a	
  safe	
  and	
  effective	
  alternative	
  to	
  general	
  anaesthetics.	
  
There	
  may	
  not	
  have	
  been	
  room	
  for	
  the	
  development	
  and	
  competition	
  of	
  2	
  techniques	
  
offering	
  potential	
  differing	
  and	
  inconsistent	
  results.	
  But	
  we	
  eventually	
  accepted	
  the	
  
nerve	
  stimulator	
  as	
  the	
  gold	
  standard	
  even	
  without	
  extensive	
  proof	
  of	
  its	
  advantages	
  
over	
  paraesthesiae.	
  	
  
	
  
Should	
  we	
  do	
  the	
  same	
  with	
  ultrasound?	
  	
  Should	
  we	
  so	
  easily	
  replace	
  nerve	
  stimulators	
  
even	
  though	
  the	
  use	
  of	
  ultrasound	
  is	
  relatively	
  young?	
  We	
  once	
  again	
  need	
  to	
  look	
  at	
  
what	
  we	
  want	
  in	
  a	
  regional	
  block	
  and	
  see	
  if	
  ultrasound	
  offers	
  anything	
  in	
  these	
  areas	
  
Initial	
  studies*23	
  indicate	
  that	
  it	
  requires	
  less	
  passes	
  (attempts)	
  than	
  previous	
  methods*.	
  
If	
  these	
  studies	
  are	
  correct,	
  then	
  the	
  use	
  of	
  ultrasound	
  would	
  make	
  regional	
  less	
  invasive	
  
and	
  may	
  improve	
  time	
  taken	
  to	
  complete	
  blocks	
  especially	
  in	
  the	
  anatomically	
  difficult	
  
patient	
  like	
  the	
  obese	
  or	
  the	
  patient	
  with	
  structural	
  abnormalities.	
  	
  
This	
  would	
  improve	
  operative	
  time.	
  	
  It	
  provides	
  real	
  time	
  imaging.	
  The	
  needles	
  depth	
  
and	
  direction	
  can	
  be	
  adjusted	
  to	
  allow	
  for	
  better	
  local	
  distribution.	
  This	
  in	
  turn	
  may	
  
reduce	
  the	
  amount	
  of	
  local	
  used.	
  This	
  also	
  enables	
  some	
  degree	
  of	
  certainty	
  that	
  an	
  
inadvertent	
  intraneural	
  or	
  intravascular	
  injection	
  has	
  not	
  taken	
  place.	
  	
  
Visualization	
  of	
  the	
  pleura	
  in	
  regional	
  blocks,	
  such	
  as	
  with	
  the	
  supraclavicular	
  approach,	
  
helps	
  avoid	
  accidental	
  puncture	
  of	
  the	
  lung.	
  	
  It	
  enables	
  “block	
  rescue”	
  in	
  blocks	
  that	
  are	
  
patchy	
  and	
  not	
  working	
  correctly	
  as	
  the	
  nerve	
  stimulators	
  and	
  paraesthesiae	
  techniques	
  
cannot	
  be	
  used	
  on	
  a	
  partially	
  blocked	
  nerve.	
  	
  	
  
	
  
	
  
	
  
	
  
	
  


                                                                               	
  

Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     8	
                                                         10/8/2011	
        	
  
	
  


	
  

	
  
Visualization	
  may	
  make	
  blocks	
  quicker	
  to	
  perform	
  as	
  being	
  able	
  to	
  see	
  the	
  nerve	
  allows	
  
the	
  user	
  to	
  direct	
  the	
  needle	
  as	
  needed.	
  It	
  may	
  be	
  easier	
  to	
  teach	
  as	
  both	
  parties	
  are	
  able	
  
to	
  interact	
  with	
  what	
  is	
  being	
  seen.	
  The	
  anatomy	
  is	
  visualized	
  by	
  teacher	
  and	
  trainee	
  and	
  
can	
  be	
  discussed	
  with	
  less	
  fear	
  of	
  complications	
  arising	
  and	
  with	
  the	
  trainee	
  having	
  a	
  
picture	
  as	
  a	
  reference.	
  	
  
But	
  it’s	
  not	
  all	
  glory.	
  	
  As	
  I	
  stated	
  at	
  the	
  beginning,	
  there	
  are	
  articles	
  to	
  support	
  these	
  
things*24	
  but	
  there	
  are	
  also	
  articles	
  that	
  say	
  there	
  is	
  no	
  evidence	
  that	
  they	
  make	
  such	
  
improvements	
  in	
  any	
  of	
  these	
  areas*25.	
  	
  
It	
  also	
  requires	
  specialized	
  teaching	
  in	
  the	
  first	
  instance.	
  	
  It	
  requires	
  some	
  dexterity	
  and	
  
good	
  hand/	
  eye	
  coordination.	
  	
  
The	
  initial	
  cost	
  outlay	
  may	
  be	
  extensive.	
  	
  It	
  may	
  not	
  be	
  available	
  in	
  all	
  areas	
  due	
  to	
  cost	
  
and	
  limited	
  battery	
  power.	
  With	
  new	
  technologies,	
  and	
  more	
  competitiveness	
  in	
  the	
  
market,	
  this	
  should	
  soon	
  decrease	
  and,	
  in	
  the	
  long	
  run,	
  the	
  benefits	
  may	
  outweigh	
  the	
  
price.	
  	
  
It	
  is	
  a	
  more	
  complex	
  piece	
  of	
  machinery	
  than	
  the	
  nerve	
  stimulator.	
  	
  It	
  may	
  be	
  more	
  
prone	
  to	
  problems	
  that	
  are	
  time	
  consuming	
  and	
  expensive	
  to	
  fix.	
  It	
  may	
  give	
  the	
  user	
  a	
  
false	
  sense	
  of	
  security	
  especially	
  if	
  he	
  is	
  inexperienced.	
  It	
  requires	
  at	
  least	
  2	
  people	
  as	
  it	
  
needs	
  both	
  hands	
  of	
  the	
  person	
  performing	
  the	
  block.	
  It	
  will	
  take	
  time	
  for	
  people	
  to	
  
relearn	
  technique	
  and	
  approaches	
  and	
  may	
  for	
  some	
  be	
  difficult	
  to	
  master.	
  	
  
I	
  think	
  at	
  the	
  end	
  of	
  the	
  day	
  it	
  will	
  prevail,	
  maybe	
  not	
  due	
  to	
  countless	
  research	
  proving	
  
it	
  is	
  better,	
  because	
  individual	
  anaesthetist	
  themselves	
  will	
  come	
  to	
  their	
  own	
  
conclusions.	
  There	
  will	
  be,	
  like	
  its	
  predecessor	
  before	
  it,	
  a	
  revolution	
  based	
  not	
  on	
  
published	
  studies	
  quoting	
  all	
  sorts	
  of	
  numbers	
  and	
  theories	
  but	
  on	
  common	
  sense	
  and	
  
individual	
  experiences	
  and	
  results.	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  


                                                                               	
  	
  	
  


Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     9	
                                                     10/8/2011	
       	
  
	
  


	
  	
  	
  


                                                             CONCLUSION	
  

	
  

I	
  think	
  that	
  the	
  future	
  of	
  regional	
  anaesthesia	
  looks	
  more	
  promising	
  than	
  ever	
  before.	
  
More	
  people	
  are	
  accepting	
  that	
  it	
  has	
  a	
  genuine	
  place	
  in	
  the	
  peri	
  operative	
  area.	
  It	
  can	
  be	
  
used	
  successfully	
  in	
  conjunction	
  with	
  general	
  anaesthesia,	
  or	
  on	
  its	
  own.	
  Its	
  place	
  in	
  pain	
  
management	
  cannot	
  be	
  denied.	
  The	
  future	
  road	
  it	
  takes	
  will	
  depend	
  on	
  patients	
  
themselves	
  and	
  the	
  doctors	
  caring	
  for	
  these	
  patients.	
  	
  

There	
  is	
  no	
  right	
  or	
  wrong	
  in	
  the	
  chosen	
  method	
  to	
  perform	
  regional	
  anaesthesia	
  as	
  long	
  
as	
  it	
  is	
  done	
  in	
  the	
  best	
  interest	
  of	
  the	
  patient.	
  If	
  the	
  performer	
  of	
  the	
  block	
  is	
  
experienced	
  and	
  competent	
  then	
  his	
  success	
  rate	
  should	
  be	
  good	
  and	
  complications	
  
minimal	
  no	
  matter	
  what	
  technique	
  he	
  chooses.	
  	
  

That	
  was	
  one	
  of	
  the	
  things	
  that	
  surprised	
  me	
  when	
  I	
  read	
  these	
  articles.	
  	
  The	
  majority	
  of	
  
the	
  studies	
  that	
  I	
  read	
  appeared	
  to	
  be	
  done	
  by	
  senior	
  doctors.	
  There	
  was	
  no	
  mention	
  at	
  
all	
  as	
  to	
  how	
  proficient	
  the	
  people	
  were	
  at	
  performing	
  blocks	
  using	
  the	
  other	
  techniques.	
  

For	
  example,	
  an	
  Anaesthetist	
  has	
  been	
  doing	
  regional	
  blocks	
  for	
  the	
  past	
  20-­‐30	
  years.	
  
They	
  first	
  used	
  parasthesia	
  then	
  nerve	
  stimulators	
  and	
  have	
  an	
  approximate	
  95%	
  
success	
  rate	
  using	
  this	
  technique.	
  If	
  they	
  do	
  a	
  study	
  using	
  ultrasound,	
  it	
  only	
  stands	
  to	
  
reason	
  that	
  his	
  success	
  rate	
  will	
  be	
  similar.	
  With	
  no	
  mention	
  of	
  his	
  previous	
  experience	
  
it’s	
  hard	
  to	
  judge	
  if	
  ultrasound	
  made	
  any	
  improvements	
  in	
  his	
  practice.	
  If	
  you	
  wanted	
  to	
  
do	
  a	
  true	
  comparison	
  of	
  the	
  techniques,	
  you	
  would	
  need	
  to	
  use	
  doctors	
  who	
  had	
  little	
  or	
  
limited	
  experience	
  with	
  regional	
  blockade.	
  

It	
  is	
  good	
  to	
  see	
  that	
  there	
  is	
  renewed	
  interest	
  in	
  regional	
  blockade.	
  In	
  my	
  experience	
  I	
  
have	
  seen	
  a	
  reduction	
  in	
  time	
  taken	
  to	
  do	
  the	
  blocks	
  with	
  people	
  who	
  are	
  anatomically	
  
difficult	
  when	
  comparing	
  doctors	
  that	
  are	
  experienced	
  at	
  using	
  only	
  one	
  of	
  the	
  
techniques.	
  	
  

This	
  alone	
  has	
  made	
  a	
  big	
  impact	
  at	
  my	
  hospital	
  where	
  we	
  deal	
  with	
  a	
  lot	
  of	
  morbidly	
  
obese	
  patients,	
  and	
  patients	
  with	
  co	
  morbities	
  such	
  as	
  diabetics	
  with	
  neuropathies.	
  I	
  
haven’t	
  myself	
  witness	
  a	
  huge	
  drop	
  in	
  the	
  amount	
  of	
  local	
  being	
  used.	
  	
  This	
  might	
  be	
  to	
  
do	
  with	
  ultrasound	
  still	
  being	
  relatively	
  new	
  at	
  my	
  hospital	
  and	
  a	
  reluctance	
  to	
  use	
  less	
  
due	
  to	
  fear	
  of	
  a	
  failed	
  or	
  patchy	
  block.	
  	
  

The	
  success	
  rate	
  and	
  onset	
  time	
  may	
  be	
  slightly	
  better	
  but	
  only	
  time	
  can	
  tell	
  on	
  this	
  one.	
  
The	
  biggest	
  change	
  I	
  have	
  seen	
  at	
  my	
  hospital	
  with	
  the	
  introduction	
  of	
  ultrasound	
  is	
  in	
  
the	
  amount	
  of	
  doctors	
  who	
  previously	
  never	
  really	
  used	
  regional	
  blockade	
  now	
  willing	
  
to	
  give	
  it	
  a	
  go	
  and	
  learn	
  it	
  under	
  the	
  guidance	
  a	
  more	
  experienced	
  hand.	
  	
  

	
  

	
  

	
  


                                                                                	
  

Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     10	
                                                  10/8/2011	
      	
  
	
  


                                                                                	
  

Personally	
  I	
  hope	
  that	
  ultrasound	
  is	
  here	
  to	
  stay.	
  This	
  is	
  not	
  based	
  on	
  any	
  studies	
  or	
  
irrefutable	
  facts.	
  As	
  an	
  Anaesthetic	
  Technician,	
  I	
  like	
  being	
  able	
  to	
  see	
  what	
  is	
  
happening.	
  It	
  helps	
  me	
  to	
  better	
  understand	
  the	
  anatomical	
  structures	
  and	
  the	
  
techniques	
  involved	
  in	
  the	
  regional	
  block	
  themselves.	
  This	
  makes	
  me	
  feel	
  more	
  
confident	
  in	
  my	
  role	
  and	
  my	
  ability	
  to	
  pick	
  up	
  when	
  something	
  is	
  not	
  right.	
  	
  

As	
  the	
  junior	
  doctors	
  are	
  being	
  taught	
  I	
  am	
  also	
  learning.	
  	
  I	
  have	
  found	
  it	
  very	
  helpful	
  to	
  
be	
  able	
  to	
  also	
  see	
  what	
  they	
  are	
  referring	
  too.	
  This	
  is	
  another	
  thing	
  I	
  like	
  about	
  
ultrasound.	
  I	
  like	
  that	
  there	
  are	
  more	
  people	
  able	
  to	
  actually	
  see	
  what	
  is	
  happening	
  with	
  
the	
  needle	
  and	
  local.	
  	
  I	
  feel	
  that	
  this,	
  in	
  itself,	
  may	
  actually	
  make	
  ultrasound	
  safer.	
  

So,	
  where	
  too	
  from	
  here?	
  	
  What	
  can	
  we	
  look	
  forward	
  to	
  in	
  the	
  future?	
  	
  3	
  dimensional	
  
ultrasound	
  imaging	
  will	
  no	
  doubt	
  be	
  somewhere	
  in	
  there,	
  perhaps	
  more	
  in	
  the	
  distant	
  
future	
  than	
  the	
  near.	
  However,	
  becoming	
  more	
  proficient	
  at	
  2	
  dimensional	
  imaging	
  will	
  
be	
  the	
  main	
  order	
  of	
  the	
  day	
  for	
  years	
  to	
  come.	
  	
  	
  

There	
  is	
  already	
  work	
  being	
  done	
  to	
  improve	
  the	
  visibility	
  of	
  the	
  needle	
  and	
  some	
  
companies	
  are	
  already	
  producing	
  such	
  needles	
  like	
  Havel’s	
  and	
  Braun.	
  	
  The	
  next	
  area	
  
that	
  is	
  long	
  overdue	
  for	
  some	
  attention	
  is	
  the	
  local	
  anaesthetic	
  agents	
  themselves	
  and	
  
the	
  different	
  adjuncts	
  that	
  can	
  be	
  used	
  to	
  improve	
  block	
  times	
  and	
  density.	
  	
  

For	
  now	
  we	
  are	
  on	
  the	
  right	
  track	
  .We	
  are	
  looking	
  and	
  demanding	
  better,	
  safer	
  and	
  more	
  
clinically	
  applicable	
  equipment	
  and	
  techniques.	
  Demanding	
  of	
  ourselves,	
  and	
  others,	
  a	
  
higher	
  standard	
  of	
  care	
  for	
  all	
  our	
  patients	
  and	
  that,	
  after	
  all,	
  is	
  what	
  medicine	
  is	
  about.	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  

	
  


	
           	
  

Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     11	
                                                     10/8/2011	
      	
  
	
  


                                                                     REFERENCES	
  

	
  
*1	
  Post-­‐operative	
  nausea	
  and	
  vomiting	
  

B	
  Gibbison,	
  R	
  Spencer	
  -­‐	
  Anaesthesia	
  &	
  Intensive	
  Care	
  Medicine,	
  2009	
  -­‐	
  Elsevier	
  
*2	
  Ambulatory	
  Anesthesiology	
  Section	
  Editor:	
  Peter	
  S.	
  A.	
  Glass	
  

Society	
  for	
  Ambulatory	
  Anaesthesia	
  Guidelines	
  for	
  the	
  Management	
  of	
  Postoperative	
  
Nausea	
  and	
  Vomiting	
  Tong	
  J.	
  Gan,	
  MD*Tricia	
  A.	
  Meyer,	
  PharmD,	
  MS†‡Christian	
  C.	
  Apfel,	
  MD,	
  
PhD§	
  
Frances	
  Chung,	
  FRCPC_Peter	
  J.	
  Davis,	
  MD¶	
  Ashraf	
  S.	
  Habib,	
  MB,	
  FRCA*Vallire	
  D.	
  Hooper,	
  MSN,	
  RN,	
  
CPAN,	
  FAAN#Anthony	
  L.	
  Kovac,	
  MD**Peter	
  Kranke,	
  MD,	
  PhD,	
  MBA††Paul	
  Myles,	
  MD‡‡	
  
Beverly	
  K.	
  Philip,	
  MD§§Gregory	
  Samsa,	
  PhD__Daniel	
  I.	
  Sessler,	
  MD¶¶James	
  Temo,	
  CRNA,	
  MSN,	
  
MBA##	
  
Martin	
  R.	
  Trame`r,	
  MD,	
  D	
  Phil***Craig	
  Vander	
  Kolk,	
  MD†††Mehernoor	
  Watcha,	
  MD‡‡‡	
  
The	
  following	
  points	
  are	
  made	
  by	
  Marcia	
  L.	
  Meldrum	
  (J.	
  Am.	
  Med.	
  Assoc.	
  2003	
  290:2470):	
  
*4	
  nitrous	
  oxide-­‐	
  laughing	
  gas	
  school	
  of	
  chemistry,	
  university	
  of	
  Bristol	
  	
  

Ewan	
  Cameron	
  and	
  Paul	
  May	
  
*5Tarnished	
  idol:	
  William	
  Thomas	
  Green	
  Morton	
  and	
  the	
  Introduction	
  of	
  Surgical	
  
Anesthesia	
  a	
  Chronicle	
  of	
  the	
  Ether	
  Controversy,	
  San	
  Anselmo,	
  CA:	
  Norman	
  Publishing,	
  
2001	
  
Wolfe,	
  R,	
  J	
  
  www.cocaine.org/cokespoon.htm	
  
*6	
  

*7	
  anaesthesia	
  rounds:	
  supplementation	
  of	
  regional	
  anaesthesia	
  	
  
Dr	
  Neil	
  Mackenzie	
  MB	
  ChB	
  FFARCS	
  	
  	
  	
  
*8	
  “Coca	
  Koller”	
  the	
  beginning	
  of	
  local	
  anaesthesia	
  
	
  Mathew	
  Hall,	
  D.D.S.t	
  
*9	
  axillary	
  brachial	
  plexus	
  block;	
  method	
  of	
  choice	
  

M	
  S	
  Brockway	
  and	
  J	
  A	
  W	
  Wildsmith	
  
*10www.general-­‐anaesthesia.com/people/august-­‐bier.html	
  
*11	
  Technical	
  Note:	
  The	
  Humeral	
  Canal	
  Approach	
  to	
  the	
  Brachial	
  Plexus	
  

Henry	
  P.	
  Frizelle	
  Department	
  of	
  Anesthesia,	
  Cork	
  University	
  Hospital,	
  Wilton,	
  Cork,	
  Ireland	
  
(Received	
  November	
  21,	
  1997;	
  accepted	
  April	
  2,	
  1999)	
  
*12	
  anaesthesia	
  rounds:	
  supplementation	
  of	
  regional	
  anaesthesia	
  	
  

Dr	
  Neil	
  Mackenzie	
  MB	
  ChB	
  FFARCS	
  	
  
*13	
  The	
  Woolly	
  and	
  Roe	
  case	
  

J	
  R	
  Maltby	
  C	
  D	
  D	
  Hutter	
  and	
  K	
  C	
  Clayton	
  
*14	
  Role	
  of	
  Ultrasound	
  guidance	
  in	
  regional	
  anaesthesia	
  

Shalini	
  Dhir,	
  Sugantha	
  Ganapathy	
  and	
  Achal	
  Dhir	
  	
  
*15	
  Ultrasound	
  guidance	
  in	
  regional	
  anaesthesia	
  

J	
  griffin	
  and	
  B	
  Nicholls	
  
*16*17*18*19	
  Use	
  of	
  the	
  nerve	
  Stimulator	
  for	
  peripheral	
  blocks	
  

P	
  Prithvi	
  MD	
  Richard	
  Rosenblatt	
  MD	
  and	
  S	
  J	
  Montgomery	
  MD	
  
*20	
  Peripheral	
  nerve	
  stimulator	
  Vs	
  paraesthesiae	
  

Anthony	
  R	
  Brown	
  MB	
  	
  	
  
*21*22	
  Ultrasound	
  guided	
  regional	
  anaesthesia;	
  in	
  search	
  of	
  the	
  Holy	
  Grail	
  

Terese	
  T	
  Horlocker	
  MD	
  and	
  Denise	
  J	
  Wedel	
  MD	
  
	
  



                                                                                	
  



	
  




Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     12	
                                            10/8/2011	
      	
  
	
  


                                                                                	
  


	
  
	
  
*23	
  Ultrasound	
  guidance	
  in	
  regional	
  anaesthesia	
  	
  

Priya	
  A	
  Kumar,	
  W	
  Brooks	
  Gentry	
  and	
  Harendra	
  Arora	
  
*24	
  Ultrasound	
  guidance	
  in	
  regional	
  anaesthesia	
  

P	
  Marhofer	
  M	
  Greher	
  and	
  S	
  Kapral	
  
*25	
  Location,	
  location,	
  location!	
  Ultrasound	
  imaging	
  in	
  regional	
  anaesthesia	
  

N	
  M	
  Denny	
  W	
  Harrop-­‐Griffiths	
  
	
  
New	
  technologies	
  in	
  nerve	
  location	
  
N	
  M	
  Bedforth	
  
	
  Local	
  anaesthetics	
  and	
  adjuvant;	
  future	
  developments	
  
M	
  D	
  Wiles	
  and	
  M	
  H	
  Nathanson	
  
Ultrasound	
  guided	
  nerve	
  blocks	
  
M	
  K	
  Peterson	
  F	
  A	
  Millar	
  and	
  D	
  G	
  Sheppard	
  
Complications	
  of	
  regional	
  anaesthesia	
  
J	
  Picard	
  and	
  T	
  Meek	
  
Regional	
  anaesthesia	
  and	
  pain	
  management	
  
L	
  Power	
  J	
  G	
  McCormack	
  and	
  P	
  S	
  Myles	
  
	
  
	
  
	
  
	
  

	
  

	
  

	
  

	
  

	
  

	
  
	
  

	
  	
  	
  




	
  

	
  

	
  


                                                                                	
  

	
  

	
  


Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     13	
                         10/8/2011	
     	
  
	
  


	
  




Morgain	
  Potter/	
  Senior	
  Anaesthetic	
  Technician	
  /	
  CMDHB	
     14	
     10/8/2011	
     	
  

								
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