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

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Conclusions
Many adults and parents of children wish to avoid
an inhalational induction. However, after receiving
an inhalational induction, two-thirds of patients
would be happy to receive one again.
When selecting and recommending a technique
for a day patient, the anaesthetist should bear the
following outcomes in mind:
• In both adults and children a sevoflurane/
sevoflurane anaesthetic regimen is associated
with a higher incidence of PONV than a
regimen incorporating propofol. In children,
sevoflurane/sevoflurane is also associated
with agitation in recovery.
• In children a sevoflurane/sevoflurane regimen
is more expensive than propofol/halothane
or the modelled cost of propofol/isoflurane.
However, the value parents place on their child
receiving an inhalational induction balances
out the additional cost.
• A propofol-containing regimen appears to
confer anti-emetic protection. The additional
anti-emetic benefit conferred by TIVA, as
opposed to propofol/volatile agent, is not
statistically significant. PONV aside, clinicians
may also select TIVA for its ‘volatile-free’
environment.
Implications for future research
The CESA project identified a number of
areas where further research is needed. Specific
anaesthetic-related issues requiring further work
are discussed below. A concern more general
to the remainder of healthcare that has been
highlighted by this study is the role of patients’
preferences in decision-making and implications
for further research in this area are also
explored below.
Use of opioid analgesics
The national practice survey indicated that
analgesia is provided by intraoperative opioids in
60–70% of adults, with a relatively small number
receiving NSAIDs either pre- or intraoperatively.
The high usage of opioids, with almost half of all
patients receiving fentanyl, is perhaps surprising,
given their association with nausea and vomiting.
The use of NSAIDs for perioperative analgesia
may, in practice, be higher than the survey
suggests, for two reasons. First, the survey did
not ask about the administration of postoperative
analgesics, and these agents may be widely used
in the postoperative period. Second, the survey
instrument asked the respondent to identify just
one intraoperative analgesic. Respondents may
have recorded opioid usage in preference to a
concurrent usage of NSAIDs.
The use of these analgesics could affect the
clinical effectiveness and costs of and patient
preferences for different anaesthetic regimens.
This is a question that was not investigated in
the CESA RCT, and further work may clarify the
impact of opioid use on patient outcome after
day surgery. Observational studies may prove
the most useful method for identification of
practice patterns.
Use of prophylactic anti-emetics
A distinction was made between prophylactic antiemetics
and those given for treatment of nausea
or vomiting. Around half the respondents do
not give routine anti-emetic prophylaxis to adult
patients, while 30–40% always use prophylaxis,
with ondansetron and cyclizine being the most
popular agents. The use of prophylactic antiemetics
was lower in paediatric patients. Despite
the prohibition of prophylactic anti-emetics, the
overall incidence of nausea and vomiting in the
CESA RCT was low. This may be because the
protocol precluded the use of intraoperative
morphine, although small numbers of patients
received other short-acting opioids. This
raises questions around the necessity for the
widespread use of prophylactic anti-emetics
revealed in the national survey. Systematic
review of the literature around the use of
these agents in day surgery may help to
answer these questions.
Risks associated with PONV
The CESA RCT for adults found that an increased
risk of PONV was associated with gender, with
women of childbearing age being more at risk,
whether undergoing gynaecological or general
surgery. Higher risk was also associated with a
longer anaesthetic duration, and with agitation
in the recovery area. It was not within the scope
of the trial to determine whether this agitation
was a cause or a consequence of feeling nauseated
or vomiting. Similar results have been reported
in other evaluations. However, further research
is required to explore the potential causes and
management implications of these events, such
as the clinical and economic impact of risk
assessment of patients.
Other combinations of anaesthetics
The CESA RCT was not able to compare all
possible combinations of anaesthetic regimens
and treatment protocols currently used in routine