Newsletter 11, December 2004 - British Ophthalmic Anaesthesia

22 Pages·2005·0.25 MB·English

by  Chandra Kumar

1
Ophthalmic Anaesthesia News
The Official Newsletter of the British Ophthalmic Anaesthesia Society
Issue 11, December 2004

Ophthalmic Anaesthesia News

Perioperative management of blood pressure for ophthalmic
Page - Contents
1. Perioperative management of surgery under regional anaesthesia
blood pressure for ophthalmic
surgery under local anaesthesi S.J. Mather and C.R. Monk
4. BOAS 2005 meeting dates

8. Report of OAS 18th Annual
Sir Humphry Davy Department of Anaesthesia, United Bristol Hospitals NHS
Meeting report
12. A relaxation technique for Trust, Bristol Royal Infirmary, Upper Maudlin Street, Bristol BS2 8HW
ophthalmic surgery under local
anaesthesia Summary
14. Peri/retrobulbar block can be
Despite Royal College guidelines, it is apparent that there is no consensus view
a safe, albeit not routine
on the perioperative management of blood pressure in patients undergoing
anaesthesia technique for repair of
penetrating eye injury cataract surgery under regional anaesthesia.
16. A fatal reaction to
diamox? We sent a postal questionnaire to members of the British Ophthalmic
17. News and information Anaesthesia Society (BOAS) in an attempt to find out if the management of
21. BOAS membership
these patients reflected evidence–based practice and whether Royal College
application form
guidelines were being followed. The literature does not strongly support the
22. Videoconference 2005
meeting details adherence to any particular level of blood pressure. Our survey shows that most
people do measure the blood pressure, do perceive there is both ocular and

cardiac risk from hypertension and that most respondents do not acutely treat

hypertension at the time of performing the local anaesthetic block.

Editor:
Prof Chandra Kumar Keywords Hypertension, local anaesthesia, cataract

Associate Editors
Correspondence to Dr. S. Mather
Dr Monica Hardwick
Dr Stephen Mather
Mr David Smerdon Introduction
Dr Sean Tighe The profile of patients requiring ophthalmic surgery is one of high age with an

increased incidence of co-morbidities and risk factors for ischaemic heart
The Society cannot be held
responsible for the statements or disease. The presence of hypertension, cardiac disease and poor physical status
views of the contributors. No part is related to a greater risk of perioperative morbidity but not to surgical
of this Newsletter may be complications. 1
reproduced without prior
There is very little evidence to equate hypertension with either ocular or
permission.
cardiac complications during ophthalmic surgery under regional anaesthesia.2

Articles of interest for future Why, therefore, is it perceived as best practice to try to control the blood
issues or correspondence should pressure perioperatively within certain defined limits?
be sent by post, disk or email:
On searching Medline and PubMed for the 10 years to 2003, few papers

Professor Chandra Kumar relevant to intraoperative blood pressure control were found. Of these, six
Department of Anaesthesia commented on or examined blood pressure changes, or discussed ischaemic
James Cook University Hospital heart disease. Four were directly relevant to hypertension or blood pressure
Middlesbrough TS4 3BW, UK control. 2-8
Tel [phone]
Fax [phone]
Website: www.boas.org Ophthalmic Anaesthesia News, Issue 11, December 2004
Email: Email: [email protected] Website http://www.boas.org
[email protected]
2

Why attempt to control blood pressure?
There are guidelines from the Royal Colleges of Anaesthesia and Ophthalmology, but the direct evidence
for control of blood pressure perioperatively is not strong. Evidence exists that tachycardia increases
morbidity in those with cardiac ischaemia.1
Glantz and colleagues found that 31% of cataract patients with two or more cardiac risk factors
intraoperative myocardial ischaemia. In their study, these events were all associated with tachycardia, there
was no difference in incidence between those having general (GA) or local anaesthesia (LA) but the
frequency of episodes was greater in the GA group.
We therefore conducted a postal survey of members of the British Ophthalmic Anaesthesia Society
(BOAS), all of whom should be experienced with patients presenting for cataract surgery, in an attempt to
find out:
1. if they actually do measure blood pressure
2. why they measure it
3. if they treat hypertension acutely

Results
The questions we asked and the number of responses to each question are shown below.

Do you routinely measure BP before eye block?
yes 85
no 19

Have you ever cancelled an eye op for hypertension?
yes 81
no 23

What cut-off point for abandoning the block?
systolic >220 47
>200 29
>180 7
Diastolic >120 44
>110 37
>100 7

EYE
Is this because of risk of:
choroidal (expul) haemorrhage 68
orbital haemorrhage 43
raised intra-ocular pressure 30

What evidence is your decision based on?
local practice 67
college guidelines 17
textbook 17
literature search 8
not evidence based 42

Ophthalmic Anaesthesia News, Issue 11, December 2004
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CARDIAC
Risk of
Increased incidence of angina 49
Periop myocardial infarction 59
Perioperative dysrhythmia 29

What evidence is your decision based on?
local practice 36
college guidelines 8
textbook 22
literature search 11
not evidence based 29

Do you acutely treat hypertension in blocking area?
yes 39
no 65

If yes, do you use: Sedation- benzodiazepine 29
propofol 12
opioid 6
other sedation 2

vasodilator 3
B-Blocker or labetalol 11
Ca antagonist 11
other 1

Do you take the BP routinely after the block?
yes 35
no 65

If yes, is it: before surgery 23
during surgery 88
both 12

Table 1. Survey questions and responses. ( n = 176 )

Discussion Most people would accept pressures above the
Of 176 questionnaires distributed, 104 were college guidelines for the preoperative treatment
returned, a response rate of 59%. of hypertension (180/100); indeed more than half
In response to the question “Do you routinely would accept a pre-block blood pressure of at
measure blood pressure before an eye block?” least 220/120.
82% said “yes” and 18% “no”. (Table 1) A little We made an attempt to find out if this was
under a quarter of respondents had cancelled because of cardiac risk or danger to the eye. We
operations because of systemic hypertension. also asked if this decision was based on local
We asked “What cut off pressure would you practice, Royal College guidelines, sources in the
accept before abandoning the block” literature, or was not evidence-based. Most

Ophthalmic Anaesthesia News, Issue 11, December 2004
Email: [email protected] Website http://www.boas.org
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people perceived the greatest risk to the eye to be coronary syndromes and cardiac morbidity.
from suprachoroidal (expulsive) haemorrhage This in itself is good enough reason for
with other significant risk factors being orbital measuring blood pressure and only operating on
haemorrhage and increased intraocular pressure. those who have their hypertension controlled.
Considering cardiac risk, a large number of It is also accepted that there is a risk to sight if the
respondents felt that increased risk of angina and patient suffers a choroidal haemorrhage during
a risk of perioperative myocardial infarction surgery, but the evidence that this occurs at any
would be associated with elevated blood pressure. particular level of systolic or diastolic pressure
Perioperative dysrhythmia was seen as a lesser appears to be lacking.
risk. For cardiac risk, fewer people based their It is therefore in the patient’s best interests to
practice on local protocols and more felt their control hypertension, and perhaps our best guide
decisions were evidence-based than for ocular is to take steps to reduce the cardiac risk factors
risk. There is thus a realisation among ophthalmic with regard to hypertension, but we may have to
anaesthetists that systemic hypertension does assume that these measures will also reduce
pose increased risk in this population yet there is ocular risk factors at the same time.
not a strong evidence basis for this. The Royal Colleges have produced guidelines
The treatment of hypertension just before that specify a level to which blood pressure
performing regional anaesthesia for ophthalmic should be controlled, but this is not supported by
surgery is controversial. The joint Colleges any specific evidence either for ocular or cardiac
guidelines 9 do not recommend the acute risk. It would be very difficult to define the risk
treatment of hypertension, although it is widely for any individual on this basis, as most
practised. Over 60% of our respondents said they recommendations for the control of hypertension
would not treat the blood pressure acutely. are based on research which looks at long-term
We were interested to find out whether those who medical outcomes from long-term treatment.
do treat blood pressure in the blocking area did so
with sedation, analgesics or with vasoactive References
drugs. Sedation of itself can bring problems such 1. Lumme P, Laatikainen LT .Risk factors for
as the patient falling asleep during surgery and intraoperative and early postoperative
then awakening in a disorientated state during the complications in extracapsular cataract surgery.
operation. 49 respondents would use sedation European Journal Ophthalmology 1994 4 (3)
whereas only 26 would use a vasoactive drug, 151-8.
despite the efficacy and known advantages of, for 2. Gozal Y, Drenger B, Robertson JE, Davis RF.
example, beta blockers in limiting the rise in ST segment changes following retinal surgery.
heart rate which may precipitate angina.10 Journal Clinical Anesthesia 1998 Jun;10 (4):297-
We also wanted to know if anaesthetists measure 301.
the blood pressure after performing the block. 3. Glantz L, Drenger B and Gozal Y.
Only 35% of respondents do this. Of these, the Perioperative myocardial ischaemia in cataract
majority measure blood pressure during surgery surgery patients: general versus local anaesthesia
and a few both before and during the operation. Anesthesia and Analgesia 2000 91 1415 – 1419
One reason often given for not taking the blood 4. Badrinath S, Bhaskaran S, Sundararaj I, Rao
pressure during surgery is that it is uncomfortable B et al. Mortality and morbidity associated with
to have repeated measurements taken by an ophthalmic surgery. Ophthalmic surgery and
oscillometric method, particularly at high lasers 1995 26 535 – 541
pressures, and this makes the patients unable to 5. Suzuki R, Kuroki S, Fujiwara N, et al. The
keep still during surgery. effects of phacoemulsification cataract surgery
There is very little evidence to inform us with via local anesthesia on preoperative and
regard to the perioperative management of blood postoperative blood pressure levels.
pressure during ophthalmic surgery under Ophthalmology 1997 104 216 – 222
regional anaesthesia. We do know, however, that 6. Rosenfeld S, Litinsky S, Snyder D, et al.
tachycardia and hypertension can lead to Effectiveness of monitored anesthesia care in
ischaemic events and the spectrum of acute

Ophthalmic Anaesthesia News, Issue 11, December 2004
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cataract surgery Ophthalmology 1999 106
1256 – 1261
7. Mamiya K, Manabe M, Aono J, et al. Blood
pressure control during eye surgery under local
anaesthesia using pulse oximetry
Ophthalmologica 1998 212 236 – 238
8. Suzuki R, Kawata K, Kuroki S et al. A
comparison of blood pressure changes in
phacoemulsification surgery with topical or
retrobulbar block local anesthesia: Part II
Ophthalmologica 1997 211 327 – 331
9. The Royal College of Anaesthetists and The
Royal College of Ophthalmologists. Local
Anaesthesia for Intraocular Surgery Guidelines
July 2001
10 Wallace A, Layug B, Tateo I et al.
Prophylactic atenolol reduces postoperative
myocardial ischemia. McSPI Research Group.
Anesthesiology 1998 88(1):7-17.

Ophthalmic Anaesthesia News, Issue 11, December 2004
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Annual Scientific Meeting of
th
BOAS will be held on 9-10 June
2005 in Jersey

For details please contact the
meeting organiser

Mr Bartley J McNeela
Consultant Ophthalmologist
Jersey General Hospital
Gloucester Street
St Helier, Jersey JE1 3QS
Email:
[email protected]

Further details will be available
when available on
BOAS website: www.boas.org

Ophthalmic Anaesthesia News, Issue 11, December 2004
Email: [email protected] Website http://www.boas.org
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Ophthalmic Anaesthesia News, Issue 11, December 2004
Email: [email protected] Website http://www.boas.org
8
Report of OAS 18th Annual Scientific Meeting, ignition, by cautery or diathermy, with an
Chicago, October 1st – 3rd 2004 oxygen enriched atmosphere under drapes are
very relevant to ophthalmic surgery. No longer
Dr Robert Johnson will I allow indiscriminate flows of oxygen to be
Bristol, UK used without real thought as to what their purpose
might be. Under open drapes carbon dioxide
BOAS was well represented with five delegates accumulation is not a great problem and, in any
two of whom gave formal presentations and all case, air is just as good at flushing the area
participated actively in discussion. The Society around the airway as oxygen. I would now
had produced a programme with parallel sessions choose the minimum oxygen concentration that
for one day of the meeting – one intended for maintains a reasonable saturation. We were
Anesthesiologists and CRNAs and the other for shown both video and live evidence of the
other personnel involved in ophthalmic dramatic fires that oxygen enriched atmospheres
anaesthesia. permit. Have you checked the instant availability
of the appropriate fire extinguishing substances in
your environment recently? Have you thought
what your immediate response to a blazing drape
on a patient’s face might be? How much use id
20ml of BSS compared with a litre of water?

Dr Robert Johnson and Mrs Ursula Johnson

As ever, the atmosphere was friendly and lively
and out-of-session discussion was interesting and

fruitful. The reception on the first evening
allowed renewal of old friendships and creation Dr Sue Bailey and Dr Christine Moore
of new ones and the food was excellent. I do not
need to remind members about the delights of We then ‘played’ Ophthalmic Anesthesia
Chicago as a clean, attractive and interesting city Jeopardy – I was not sufficiently quiz game or
with superb galleries, museums and concert hall. TV orientated to know what this was – but soon
This year we had the added interest of the new found out! It was stimulating, somewhat
Millennium Park – yes it is new: just a little late. educational and certainly a good wake-me-up
(not that I was anywhere near asleep of course) at
The first session included Chandra Kumar’s the end of the session. Like many quiz games, the
excellent talk on visual experiences during eye objectivity of the scoring was occasionally in
surgery under regional orbital anaesthesia and a doubt but we had all the proper software to make
fascinating, if worrying, presentation by Jan it very professional. I think it might make a good
Ehrenworth on Fire in the Operating Room. I felt addition to a BOAS meeting.
that I knew beforehand about the risk of lasers
and electrical faults but was surprised that fires
are not all that rare – about 100 each year in the
USA – and that those resulting from drape

Ophthalmic Anaesthesia News, Issue 11, December 2004
Email: [email protected] Website http://www.boas.org
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Dr Robert Hustead and Mrs Joy Hustead Mrs Ursula Johnson, Dr Robert Johnson, Mrs
Arline Fanning, Dr Gary Fanning, Mrs Suchi
On the second day (the day of parallel sessions) Kumar and Professor Chandra Kumar
among the gems were an excellent talk by Joseph
Bayes on implanted pacemakers. Some of the
content was good revision but much was new (to
me anyway). Douglas Bacon presented a first
class review of the stormy relationship between
succinyl choline and eye surgery – the title
Another Myth ‘Busted’ hints at the conclusion. I
was not present at the parallel session but was
interested to see what was thought to be relevant
for the delegates. Talks included A Proven
System for Prevention of Ophthalmitis,
Comparison of billing systems between hospitals
and ambulatory surgery centers (maybe not
highly relevant to the NHS), Knocking Down the
Generational Gap (I don’t think that was another

quiz game) and Everyday Challenges in Running
an Ophthalmic Service. Dr Steve Gayer with wife and son

Among the highlights on Sunday were Treatment In all, a very good meeting. Any ophthalmic
for Blind and Seeing Painful Eyes by Leonid anaesthetist in the U.K. would gain a lot from
Skorin – unfortunately I had to miss this talk but attending one meeting of OAS at least. Maybe
my well informed spies told me that it was truly 2005 would be a very good time if the dollar
excellent and added a further dimension to the remains as weak as at present. Normally, the one
ophthalmic anaesthetist’s role. The meeting down side of this meeting is the cost of staying in
ended with the usual Anesthesia Case Discussion Chicago – but the Westin Hotel is a very good
Panel – the cases were interesting and the venue and, as I have said, Chicago is a delightful
discussion was energetic and showed the city. You can be absolutely sure of a friendly
diversity of views that can exist on patient reception and good science.
management: more than one of them may be
appropriate.

Ophthalmic Anaesthesia News, Issue 11, December 2004
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Publication of this
newsletter has been
possible by a
generous donation
from

Abbott Laboratories
Ltd
Queenborough
Kent, ME11 5EL

Ophthalmic Anaesthesia News, Issue 11, December 2004
Email: [email protected] Website http://www.boas.org