Aanesthetic Agents for Day Surgery - NIHR Health Technology ...

Introduction
Day-case surgery is responsible for an increasing
proportion of the surgery performed each year. 229
The benefits to the patient are the avoidance of a
hospital admission and minimal disruption to their
lifestyle. To achieve rapid discharge from hospital,
debate has surrounded how best to avoid postoperative
morbidity (e.g. pain, nausea and vomiting).
For this reason, the choice of anaesthetic
agent, technique and personnel has been seen
as critical. 1,144
The literature review (see chapter 2) reports
published practice patterns, variations and trends
for adult and paediatric anaesthetic practice. The
aim of the present survey was to inform the investigators
of the anaesthetic agents and techniques in
common use in paediatric and adult day surgery in
the UK. The national survey also provided data for
the economic analyses, which were specified in the
economic evaluation protocol. The main areas
explored were: premedication; induction; maintenance;
prophylactic and treatment anti-emetics;
analgesia; local anaesthesia; and duration of day-case
procedures. This information was used to inform the
development of the sensitivity analysis, to model the
impact of using other anaesthetic techniques and to
extrapolate the results of the evaluation in context
with current clinical practice in the UK.
Method
The specific objectives of the national survey were:
• to provide a range of estimates for the duration of
procedures in the selected areas of day surgery
• to characterise the use of premedication agents,
induction and maintenance agents, low flow
rates, prophylactic anti-emetics, intraoperative
analgesia, local anaesthetics, suxamethonium and
non-depolarising neuromuscular blocking agents
• to elucidate the treatment of PONV.
Preliminary survey
In January 1999, a preliminary survey of paediatric
anaesthetic practice was conducted to inform the
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Chapter 3
Health Technology Assessment 2002; Vol. 6: No. 30
National survey of anaesthetic practice for
paediatric and adult day surgery
choice of alternative anaesthetic agents for the
arms of the paediatric empirical study. Twenty-nine
consultant anaesthetists from 11 specialist paediatric
hospitals were surveyed. The response rate was 90%
(n = 26). The majority (80%) of these anaesthetists
used propofol as their usual choice for the induction
of anaesthesia. Eight per cent reported using
sevoflurane for induction. A large number of
anaesthetists used isoflurane (64%) or halothane
(24%), with or without N 2O, and a small number
(8%) of anaesthetists used sevoflurane for the
maintenance of anaesthesia. The results of this
preliminary survey were combined with the findings
from the literature review (see chapter 2) to define
the selected alternative anaesthetic agents in the
paediatric empirical study.
National survey
The national postal survey used a structured data
collection instrument comprising closed questions
about key aspects of anaesthetising a patient for
day surgery (see appendix 11). These questions
were formed from the results of a pre-pilot survey
of paediatric anaesthetic practice. The structured
questionnaire was then piloted in a sample
(n = 19) of consultant anaesthetists based in one
of the NHS trusts involved in the empirical study.
The pilot survey generated a 90% response rate
and worked extremely well. No changes were
made to the survey instrument.
It was assumed that answers to the survey questions
would be procedure specific, and so selected areas
of day surgery and examples of procedures were
selected in order to focus anaesthetists’ responses.
This means that the results will not be generalisable
to all types of day surgery, as the answers are
specific to the named types of operations. The
selected areas of day surgery matched those
included in the empirical study. These areas were
urology (e.g. cystoscopy) and orthopaedics (e.g.
knee arthroscopy) for adult practice, and general
surgery (e.g. circumcision) for paediatric practice.
Simpson and Russell’s 32 survey of anaesthetic
practice summarised the main approaches used to
anaesthetise patients for day-case gynaecological
laparoscopy, and this procedure type was not
represented in our survey.
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