Reprinted from Anaesthesia
Points West Vol. 17 No. 2
An interesting
view from the days when epidurals were not so common as today.
I Did It My Way
Confessions of an
Epiduralist
Dr. W. M. Maidlow,
Consultant Anaesthetist, Southmead Hospital 1948-1977
British anaesthetists of my generation never seriously considered
the advantages of epidural analgesia over spinal analgesia until Gordh1
introduced Lignocaine in 1948 and published his paper in "Anaesthesia"
in 1949.
My interest was further stimulated by a typically original and
timely contribution in 1950 by Dr. Bryce-Smith2 of Oxford whose
generous guidance to innumerable anaesthetists up and down the country has been
responsible for worldwide interest in the subject. Finally I was influenced by
what most British anaesthetists would regard as the original and definitive
work on epidural analgesia to be published in this country - the work of
Dr.Philip R. Bromage in his paper entitled "Lumbar epidural analgesia for
major surgery below the diaphragm"3
All aspiring epidural anaesthetists who have not read and learned
all there is to know from these two papers which contain a maximum of honest
reliable information should not consider themselves in command of the
fundamental principles on the subject.
In August 1951 I performed my first epidural. It was interesting
in that the case was a Caesarean section of toxaemia and prematurity and also
because epidural analgesia has now become the preferred method for effecting
pain relief in most maternity units.
My first epidural for urological surgery was for an open operation
for randomised implant to the bladder in July 1952. In the intervening months I
had used epidural analgesia for a number of Caesarean section operations and
then in January 1953, I first used this method of anaesthesia for a
transurethral prostrate resection.
In 1952, the year of Bromage's paper, 1 gave 115 epidural and 93
spinal anaesthetics. I had been appointed anaesthetic registrar at Southmead in
September 1946 and during the ensuing 4 years the number of "spinals"
performed increased from 27 to 247 in 1950. Figure 1 indicates the trend taken
by "epidurals" to outstrip "spinals" from 1952 and Figure 2
shows how in 1960 the cumulative total of 1930 epidurals defined over 9 years
passed the total of 1890 spinals in 20 years. Included in the total of 1890 are
544 spinals performed during various appointments at home and abroad prior to
my appointment at Southmead in 1946.
Figure 1 Annual totals of
spinal and epidural blocks.
The diminishing
numbers of blocks from 1964 are not due to any lack of interest but to the
increase in both junior and consultant staff at Southmead and the availability
of mechanical ventilation.
Figure 2 Cumulative totals
of spinal and epidural blocks.
The final total
for epidural block exceeds that for spinal block by approximately 1000.
Among the spinal anaesthetics used in the early years were
Stovaine which was amylocaine in a strength of 5%, known as Barker's solution,
and 10%, Chaputs' solution (specific gravities 1025 and 1080 respectively). The
latter was short acting giving barely an hour's block. These two and Nupercaine
1:1500 were the standard spinal anaesthetic drugs issued in my units in the
Army and I found them very satisfactory. I was introduced to Spinocaine in
Bristol in 1940. This drug contained Novocaine, strychnine sulphate, alcohol as
a solvent, sterile water and amylo-prolamin. There was a somewhat complicated
injection procedure requiring one or two CSF aspirations and Trendelenberg tilt
to achieve the right level of anaesthesia.
Procaine was used as crystals which were allowed to dissolve in
CSF, and then re-injected. Amethocaine was presented as Spinal D solution and
as crystals which were useful in prolonging the action of lignocaine when mixed
with it for use in epidural block for longer lasting procedures before the
introduction of bupivacaine. Finally Nupercaine in strengths of 1:200 and
1:1500 for longer duration which latterly became the drug of choice for spinal
analgesia. For many years both in the army, and afterwards, I used a 1:200
hyberbaric solution of Nupercaine very successfully until it was withdrawn. It
necessitated quite a large volume of CSF barbotage which invariably ensured a
successful block, as one had to be certain that all the solution entered the
theca. The publication of a number of cases of neurological sequelae following
spinal analgesia is put into correct perspective when one realises that the
ester drugs, Nupercaine, amethocaine and procaine can only be autoclaved once
without loss of intensity and up until fairly recent times the ampoules were
taken straight from their boxes or else kept in Phenol. The most famous of such
cases were the Chesterfield fatalities. Lignocaine was the first of the new
series of local anaesthetic drugs which can be autoclaved any number of times
without loss of intensity. Carbocaine 4% or mepivacaine and Citanest 5% or
prilocaine were introduced as being less toxic than Nupercaine and although of
shorter duration can also be re-autoclaved.
The 1953 figures in figure 1 show in which direction my enthusiasm
was now directed and I was invited to read papers to the South West Society of
Urologists in 1953 and 1956 and to demonstrate the technique for urological
surgery in 1956 and for gynaecological surgery in 1962 at meetings of the
Society of Anaesthetists of the S.W. Region. My interest was encouraged by the
surgeons with whom I have worked particularly by Professor J.P. Mitchell, Mr. Norman
Slade and Mr. Clive Gingell and also by the gynaecologists Mr. John Crossley
and Mrs. Marjorie Bennett.
The method which has given me the most satisfaction was described
by Heldt and Moloney5 in 1928 and known as the postulated negative
pressure technique. It was reintroduced by Gutierrez of Buenos Aires in 1932
with his 'hanging drop'6 but demonstrated more clearly by means of
Odom's indicator or Odometer (New Orleans, 1936)7. I believe that
this method is the simplest, most obvious and most foolproof way of effecting
an epidural injection.
It has been stated that in 16% of subjects there is no obvious
negative pressure in the epidural space but with scrupulous attention to detail
in positioning the patient fully flexed and slightly head down - to diminish
pressure of the CSF from the dura and by using a small calibre 20 gauge 3"
Harris needle8 the chances of failure grow less as experience and
confidence increase.
You may question my wisdom in so religiously adopting this method.
If you strongly believe that an "Epidural" is indicated then it is
important to find perfection and let nothing stand in your way. This even
extends to doing it yourself and not handing it to a registrar or trainee.
I trust what I see with my eyes more critically than what I feel
with my fingers. Having observed the negative pressure there is no possibility
of a spinal tap and as the solution is slowly injected there will be added
confidence by the ease of injection. N.B. You must always use a glass syringe.
There is no need to wait for a test dose when you have witnessed the passing of
the bubble in the odometer towards the patient - in fact the act of waiting for
5 minutes for tests may encourage the possibility of the patient or the
anaesthetist moving the point of the needle slightly and then introducing the
great danger of a total spinal when the full dose is administered. Also there
is no point in giving a test dose and trying to illicit a response if the
patient is asleep.
Total spinal or total epidural anaesthesia can sometimes occur.
The solution has permeated or penetrated the dura either directly or via the
dural cuffs in the intervertebral foramina and paralysed the motor nerves.
Admittedly some conscious patients cannot lift their legs after an epidural
which was supposed only to effect a sensory blockade. Here the solution may
have been too concentrated and if this c<Jn happen to a young fit subject
undergoing a herniorraphy or varicose vein operation using a weak solution like
1.2% lignocaine or 0.25% bupivacaine given slowly through a narrow bore Harris
needle using the negative pressure with the patient head down, how much more
likely is a total epidural or spinal to occur when larger volumes are given too
fast by the loss of resistance method, to a poor risk patient. One must also
remember that if the CSF pressure is low or a "dry· tap occurs then there
is danger of the solution reaching the ventricles of the brain with the patient
head-down. My advice is to pay attention to detail and never be guilty of over confidence.
A first class assistant or technician is worth his weight in gold
and any epidural anaesthetist who lacks the initiative to train his staff is
fully at error.
The atmosphere surrounding the performance of an epidural
injection is very important. A number of gowned and washed figures none of whom
the patient can be expected to recognise, far less trust, and all telling him
something about how to position himself and what to expect only serves to
confuse very effectively a sedated patient and produce a state of chaos. All
frivolous talk is anathema in this respect. The technician or assistant should
gently position the patient with his back fully flexed, - "Will you try to
curl up like a cat" - and horizontal to the edge of the table with his feet
and ankles not suspended over the table margin. I then usually make a few
sympathetic remarks such as "Just a little cold on your back, that's very
good, now over on to your back, gently does it". All this may or may not
be necessary depending on whether the patient has been fully anaesthetised or
given a small intravenous injection of Valium.
I believe very strongly in noise abatement in the theatre for
patients under any form of regional anaesthetic. This includes talking and even
teaching students. Considerable restraint is required from all theatre staff
and unnecessary clatter of instruments is to be deplored. Stray visitors should
also be made aware of this important aspect. It should not be necessary to have
to inject a further dose of hypnotic just to enable the surgeon to tell his
latest funny story. Occasionally I have felt a need for a notice in the theatre
stating that "regional analgesia is being used for this case".
It is much more difficult to teach junior staff an epidural than a
spinal. They learn more by watching failures, difficulties and successes and
the difficulties may be just as valuable material as the successes.
After raising the intradermal wheal and infiltrating the tissues
with a hypodermic needle I use a No.1 needle for opening up a nice hole in the
skin like an introducer which gives me a good idea of my direction, will
certainly inform me if I make contact with a spinous process or a lamina, and
avoids skin being carried inwards by the Harris needle. I advise those performing
an epidural block to sit comfortably relaxed with the eyes over and above the
needle, I rest one foot, the left one on the rail of the trolley or the base of
the table and rest my left elbow on my left knee and the knuckles of my left
hand against the patient's spine. The fingers of both hands grasp the hub of
the needle so that if the patient withdraws his back then your hands move with
the patient.
The needle is advanced slowly through the ligaments trying to
appreciate the feeling of double resistance as it enters and leaves the
ligamentum subflavum. I prefer the midline approach whenever possible as there
is only one plane to envisage and you have the advantage of the feel of the
ligaments and muscle and you know that if you hit bone it must almost certainly
be the lamina of the vertebra below. The Harris needle hub is designed to
assist the finger grip. The stillete is withdrawn when the needle is firmly
held in the ligament so that it does not sag towards the floor and the odometer
is then firmly attached.
The movement of the bubble in the odometer may be slight or
complete and can be made more convincing by rotating the needle through 1800,
increasing the degree of spinal flexion and ensuring that the indicator is
fitting tightly. Be sure not to advance the needle by more than a fraction of a
millimetre once some movement has been observed. Seeing the negative pressure
is always a satisfying experience.
The selected interspace is, in practice, unimportant. Take the
easiest space in the mid-line and success comes more ohen than failure. Do not
go for an unnecessarily low space just because you are worried about not
reaching the perineum or for fear of it rising too high. If either of these
worries beset you an epidural is probably contra-indicated. If you are
confronted by fairly prolonged perineal surgery such as abdomino perineal
resection or vaginal hysterectomy and pelvic floor repair you may need to give
a larger volume of solution with the patient tilted head up if you have chosen
L2-3 or L3-4 for your injection.9 I keep the index and middle
fingers of my left hand on the two vertebral spines all the time I am locating
and infiltrating the space because I after infiltrating you may no longer be
able to palpate a space.
The volume of solution used depends on the size, age, general
fitness of the patient and the severity of the operation and not so much on the
segmental level desired. It is difficult to give too much if you use the lowest
concentration compatible with sensory block and try to avoid concentrations
which produce motor block. Speed of injection should be about 0.75 ml per
second. One of the advantages of using a weak solution of Bupivacaine is that
you obtain a differential block in which the more lightly myelinated motor
fibres escape. This effects a reflex flaccidity by interrupting the sensory
afferent pathways leaving the motor pathways intact. Intercostal movement
remains unimpaired and constitutes one of the great safety factors of this
technique over a spinal when used in poor risk pulmonary and cardiac patients
and of course in Obstetrics. For this reason particularly, I am always happier
if I get a certain degree of hypotension with an epidural than if I had either
inadvertently or even intentionally produced it with a spinal.
Purposefully induced hypotension is not only unnecessary but often
unsafe in elderly poor risk patients and it must be understood that it is not
my intention to suggest that the advantage of epidural block is the production
of hypotensive anaesthesia. To obtain good vasoconstriction of the prostatic
bed an epidural should paralyse the parasympathetic outflow i.e. three nervi
origentes S 2, 3, 4, (as demonstrated by the obviously flaccid penis) with as
little sympathetic block as possible to avoid too great a fall in blood
pressure in patients with cerebral and cardiac atheroma. 15-20 ml of 0.25-0.5%
bupivacaine with adrenaline 1:200,000 via L 2 3 or L3 4 interspace in an
average patient with the table horizontal is a guide to the epidural dosage for
transurethral resection. The block extends for 4 or 5 segments on either side
of the interspace used. A head down tilt will increase the spread to the dorsal
region at the expense of the sacral area. Bleeding will be diminished as a
result of loss of tone from the complete sensory, the sympathetic, and the para
sympathetic block of the area affected.
Perhaps a few words concerning spinal block. One has to admit that
a spinal block is usually more intense and more predictable, and may be
selected when you really believe that a regional anaesthetic must take
precedence over a general anaesthetic. Neurological complications should be
unlikely with proper care. The use of Carbocaine may be preferable to the more
toxic and longer lasting Nupercaine and good experience was gained with the
former while Nupercaine was off the market.
A poor risk patient with severe and crippling pulmonary disease is
an excellent candidate for a low spinal with, if necessary, a local
infiltration of the abdominal wall. Headaches are still a problem after a
spinal. The patient can get up sooner after an epidural and a further important
disadvantage of a spinal is the detrusor weakness of the bladder with an
absence of " vis a tergo" postoperatively to keep the bladder empty
and avoid clot retention.
Seldom does one experience the worry of nausea during the
operation under epidural as so often occurs under spinal analgesia possibly due
to central hypoxia. A smaller dose is needed for patients with occlusive
vascular disease and blockade will develop more slowly. In these cases aback to
a given volume will spread 1.5 to 3 times as far as it would in the case of
non-arteriosclerotic patients. This shows how experience and knowledge and
observation are all more important than just understanding the technique.
The surgeon asks for an operative area that is completely relaxed
whether it be for the resectoscope or his abdominal retractors and a field in
which the vessels do not bleed unduly. These conditions may not be achieved by
means of the general anaesthesia using a relaxant technique and IPPV. With
nitrous oxide, oxygen and relaxant a greater strain is thrown on the heart and
circulation; the cardiac output is diminished by interference with the normal
venous return from altered pulmonary resistance and compliance and with a
corresponding increase in oozing from the vessels of the prostatic bed. There
are inevitable peaks and depressions of blood pressure no doubt due to periods
of trauma and stress breaking through the sensory arc in patients anaesthetised
by a nitrous oxide, oxygen and relaxant technique. Such reactions are not seen
in patients under epidural blockade.
Another observation does not escape my notice. This is that
however complex the monitoring devices may be and however scientific, I am
continually impressed by such simple facts as a patient who is warm and pink
and also has on easily palpable pulse at the superficial temporal, with small
pupils and is not sweating and above all, with a rebreathing bag moving
spontaneously with respiration. I find that these signs, particularly the last,
are the best indications of the state of the medulla that are available to the
anaesthetist. Sometimes I must confess that the more monitoring devices that
are in use, the more worried I am apt to become.
It has been my impression when leaving a discussion on the
advantages of epidural and analgesia especially when it concerns urological and
gynaecological procedures, that many of those present were more confused in
their beliefs than they were before.
Before, they did at least hold a reasonable and sound views on what was
safest and most indicated and maybe preferred by the patient. I believe that
these two disciplines, urology in the aged and gynaecology demand close liaison
between surgeon and anaesthetist. We are frequently both confronted with a an
elderly patient who is not in the best of health and ways an operation in which
the ultimate benefit of relieving prostatic obstruction will almost always
outweigh the risk of anaesthesia. We therefore have a duty to minimize risk by
administrating an anaesthetic that will not increase the risk and yet will
facilitate the task of the surgeon. After careful assessment we are still faced
with a patient who often presents cardiac or respiratory problems, or
both. He is elderly and sometimes
mentally confused, which is not improved by hospitalisation and is not
necessarily an anaesthetic hazard. Age
itself may not be the important factor, but the preoperative condition, be it
bronchitis, emphysema, bronchospasm, or incipient heart failure, which is
directly related to the mortality.
Senile cerebral degeneration offers a poor prognosis and I think this in
itself, which is obviously hard to treat, is perhaps the most important single
factor and the announcement successful survival. The opposite of this is the man whose mind is clear who would
does exceedingly well in spite of his age or any other adverse factor. About 90% can be operated onsafely over the
age of 80 with a 20% mortality whatever the anaesthetic, while below age 70 the
mortality is less than 2%.
Remember that having selected an epidural this decision is never
intended to imply hypotensive anaesthesia or bloodless field surgery - call it
what you will. But a slightly lowered blood pressure with a patient properly
sedated and at rest eases the strain
on the coronary circulation since coronary blood flow is more closely related
to the metabolic demands of the heart than to the actual blood pressure. However,
the airway must at all times be faultless. Generally I achieve this either with
a well lubricated pharyngeal airway and a source of oxygen flowing. or with a
Ventimask. This is so much better than breathing a dubious mixture of gases and
the surgeon visualises the operation site the more clearly. I try to achieve
minimal sedation with a suitable combination of Omnopon and Scopolamine given
one hour before the epidural. Any other combination particularly using a
phenothiazine derivative or atropine only serves to agitate the patient who
becomes restless and dry mouthed so that he requires more sedation and suffers
from greater depression of respiration.
Phenergan in these patients and indeed in conjunction with any
regional block seems to encourage patients to fidget about, and at its worst may
also potentiate hypotension. It also seems to inhibit analgesic absorption.10
On arrival in the anaesthetic room having taken the blood pressure, I
administer 5-10 mg Valium intravenously and then set up and intravenous drip.
The block is then performed and the patient positioned on the operating table
following a 125 mg. intravenous dose of thiopentone, sometimes less, never more
initially, for comfort.
The object is to present a patient who is sedated, relaxed and who
will not strain or cough during surgery, and who will not vomit afterwards.
Recovery must be quiet and pain-free and should be accompanied by minimal
bleeding with no respiratory depression or breathing problems. After a T.U.R.
or R.P.P. I like to see the final washout the colour of Vin Rose and am
concerned if it is the colour either of a rich Burgundy, or perhaps even worse,
of Vin Ordinaire. Blood must be available but the blood pressure is allowed to
return to normal slowly with the patient nursed head down with intravenous
fluid running, and only in extreme circumstances should one resort to
sympathomimetic drugs for restoring the blood pressure. 500 ml. Dextran 70 may
give the support that you need to bring about a blood pressure back to a
comfortable level. A small dose of intravenous atropine for a pulse below 50
will invariably improve the cardiac output. Special attention should be paid to
the moment when the legs are lowered. This is usually followed by a fall in
blood pressure.
These patients are not good breathers after a nitrous oxide,
oxygen relaxant technique, nor for that matter do they breathe too well under
nitrous oxide, oxygen, halothane. Both these techniques, as I have already
suggested, raise venous pressure and the coughing and straining that occurs
with an endotracheal tube, or following the inadequate use of scoline, and the
possibility of apnoea, hypoventilation and coughing on extubation, may provoke
bleeding and clot formation. But there are no statistics to suggest that
general anaesthesia in these subjects is any less safe than an epidural in safe
hands, performed with proper care and attention to the hazards of hypotension,
gives the surgeon ideal conditions and is better for the patient, and
especially one who has experienced a cerebrovascular accident or myocardial
infarct; but it is still not necessarily 100% safe. This is the argument that causes confusion. A general anaesthetic may provide rather
more latitude to errors of judgement and even technique in the patient who has
had a cerebral vascular accident or myocardial infarct, that it is still not
less so 100% safe. Surgeons nowadays are much kinder folk than they used to be.
They tend to be much more tolerant and more grateful, and certainly more
respectful towards their anaesthetic colleagues. If you give a good general
anaesthetic. even if the patient does not survive, he will invariably say
"No fault of yours. you did your best". If the same result happens
following an epidural, people are apt to be a little more critical and less
tolerant and to say "Well it might have been all right if he'd used a
general". The philosophy of life and experience of the elderly enables
them to accept epidural analgesia with a confidence not always seen in their
younger brethren. Here I make an exception in the case of the pregnant woman at
delivery.
I think an epidural block is perhaps even more beneficial for the
transurethral resection than for retropubic prostatectomy. Firstly TUR is often
performed because the patient, for one reason or another, may not be expected to
stand up to the longer, more serious procedure and secondly. the quiet field is
a great help when working down the telescope for swiftness and accuracy in
cutting and coagulating. It is like firing at a target. If the target is
constantly on the move, it must be more difficult to hit the bull's eye!
Comparable conditions can only be achieved by relaxant techniques and many
anaesthetists think this is not justified for a procedure that does not demand
abdominal relaxation. It is in the straining patient that the operation of
T.U.R. proves difficult. Bladder perforation may complicate matters or
inadequate resection brings the patient back again too soon for a second
operation.
What about bleeding postoperatively? I hope I shall not be
criticised for stating that I believe that it is the patient who bleeds and
gives trouble with haemostasis on the table. who continues to bleed afterwards
and may have to return for clot evacuation. Generally speaking the patient who
has a slightly lowered blood pressure and who gives minimal trouble during
surgery will have an uncomplicated recovery. There must of course be
exceptions. Postoperative fluid therapy is vital to these patients to maintain
diuresis and to ensure adequate fluid intake, since absorption from the bowel
in old age is always unpredictable. They are, however, all encouraged to drink
as soon as possible after surgery, and the patient who has had an epidural is
at some advantage here. Early ambulation must be the rule to diminish the
chances of venous thrombosis, and physiotherapy is mandatory.
The association between perforated duodenal ulcer and
protastatectomy should be remembered. This complication may simply be due to
alteration in feeding habits and early recovery may help in this respect.
It would not be fair in a paper such as this is I were to omit
what is probably the hazard which is the least avoidable. I refer to the remote
possibility of paraplegia following epidural. There are more reports of this
after spinal than after epidural and some cases are not reported.4
We must remember also that general anaesthesia has its unpredictable risks. But
it is not my intention to itemise all the well documented accounts of
neurological complications.
The best account of a case was reported by a surgeon named
Urquhart-Hay of New Zealand,11 It happened in 1969 and the patient,
though he died from metastatic carcinoma, was never able to walk after his
urological operation. This was almost certainly the result of the anterior
spinal artery syndrome12 13 in which the hypotensive effect of the
epidural together with the direct effect of adrenaline, caused a thrombosis of
the nutrient vessels of the cord. These vessels were already compromised by
generalised arterio-vascular disease which was a post-mortem finding in this 62
year old patient. He received 36 ml. of 1:500 lignocaine (540 mg.) with
adrenaline (amount and concentration not stated). Here is another warning
against overdose and excessive hypotension. The patient was also described as
being in a steep head down position with his knees bent to avoid him slipping
off the table. One should not need such a steep slope for any urological
procedure. Some readers may be aware of a similar case in the Southmead
records, which was not fatal, but equally tragic.14
Any discussion on epidural techniques naturally raises the
question of the method by which the block is carried out. Without going into
voluminous details you are really either a" Dogliotti" or a
"Gutierrez" man - Ioss of resistnce or negative pressure. You use a wide bore Tuohy15
needle or a narrow bore Harris. I have only described the latter which I used
consistently.
The Dogliotti16 brigade makes use of the fact that the
dura is pushed away from the advancing needle as air or fluid is injected
through a 20 ml. syringe. The
recognition of the sudden release of resistance as the needle passes from the
ligamentum subflavum into the epidural space is what constitutes the end point.
Giordanengo17 postulated that the fluid under pressure resembled a
liquid trocar and Bromage18 described the end point as having an
atraumatic quality using a gentle stream of fluid to repulse the dura instead
of using a traumatic shaft of steel. But Brooks19 introduced his
indicator which is an attempt to combine the visual aid of the odometer with
the loss of resistance principle described above Brooks suggested that this
could be seen to work in the 16% of cases which are said to show no negative
pressure. It depends on warming a glass bulb blown on to the end of an Odom's indicator
with the warmth from the palm of one's hand. This method increases the
complexity and has not found a place in the epidural sets at Southmead
Hospital. In addition there is Macintosh's balloon negative pressure indicator20
21 and other less simple devices.
I have made little reference to the advantage of epidural block in
gynaecology. He who can sit comfortably contemplating a relaxed female perineum
which on incision bleeds about half as much as the patient who is receiving a
general anaesthetic must be one who is grateful for his anaesthetist taking the
trouble to provide these conditions. In contrast the gynaecologist who has
received a direct hit from the female urethra during coughing and straining
episode is one who is seldom likely to appreciate the funny side more than
once.
Summary and Concluding Remarks
There are a number of advantages that I personally see in favour
of an epidural for lower abdominal surgical procedures.
Firstly, by means of one simple injection we achieve complete relaxation
and pain relief without any respiratory depression (Respiration may in fact be
improved in patients with Emphysema and Bronchitis). There is diminished
bleeding and a modification of the response to stress as shown by a delayed
fall in the eosinophilic count after operation. There is a definite reduction
in post-operative pain and therefore vital capacity is maintained making
pulmonary complications less likely. With meticulous care the failure rate
should be kept as low as 1-2% year in, year out.
I am against the use of general anaesthesia for these procedures
for a number of reasons. I have suggested that IPPV interferes with pulmonary
circulation and that these patients take longer to recover normal respiration.
This may be due to the lowering of pCO2 below the limits to which
emphysematous and bronchitic patients are accustomed. Methods which utilise
ganglionic blockade with menthonium compounds are less effective in control of
bleeding. Blood pressures with these drugs may rise or fall quite precipitously
when starting or stopping their use. Some of the patients have bronchogenic
carcinoma and the myasthenic syndrome so that neostigmine resistant
curarisation may be a problem. In addition, patients taking B blockers may
exhibit a to extreme bradycardia following atropine nestigmine reversal.23
24 However, I constantly keep reminding myself, and used to tell those
who passed through Southmead Hospital and became interested in the benefits of
epidural blockade, to try to remain aware that when I or they resort to other
methods, results may be less satisfying.
Surgeons soon learn to appreciate the benefits an epidural in
relation to the accuracy and speed of their own technique. They know when an
epidural has been given. One could almost say with little exaggeration that
surgeons are spoilt when they are provided with a patient under an epidural, so
that they are unhappy when the anaesthetist fails or decides not to perform an
epidural. They have been known to exclaim "Why no epidural today? ", or "What is the anaesthetic
today? ", and facetiously to imply
that it could well be heparin.
Never make the excuse of being too late or of not having suHicient
time to perform an epidural block. The technique of continuous epidural block
for Obstetrics has become established and is a development of work by Simpson
and Parkhouse25 and others26 in relation to therapeutic
epidural block for post operative pain relief. More recently epidural block has
been used effectively in association with Helmstein's technique of bladder
distension.28 If one does not believe and practice the benefits of
epidural block for urological, gynaecological and general surgery, then one is
decidedly less well equipped to perform an epidural competently and effectively
when it is indicated for these and other procedures requiring pain relief.
Finally, I would like to pay special tribute to my colleagues at
South mead Hospital. Dr. Terence Steen with his keen interest and skill in
regional analgesia reacted with similar enthusiasm on the advantages of
epidural analgesia for the special
procedures mentioned above. For me this has been a rewarding experience
and partnership. Dr. Kay Huggins in the early years of heady enthusiasm
continued to curb our oversanguine thoughts of hypotension and reminded us that
other methods might have in-built safety measures and generally steering a much
respected middle course. Later we benefited greatly from the appointments of
Dr. Shu Lahiri and Dr. James Mulvein who was instrumental in setting up the epidural
service in the Maternity Department.29.30 It may be relevant that
these latter two were previously on the junior anaesthetic staff at Southmead
Hospital. Without the support of those mentioned the epidural technique could
not have developed so effectively at Southmead Hospital. Between us it is my
sincere hope that we have informed, instructed and interested many who have
passed through the Anaesthetic Department. From this paper it can be seen how
the introduction, development and popularity oi epidural analgesia and its
advantages over spinal analgesia have exactly spanned my period as a Consultant
Anaesthetist and how my colleagues at Southmead helped to expand and teach the
technique for many uses.
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If