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Chapter 5
new coloscopes,
13
the water method,
14
and experienced endoscopists make colonoscopy
without sedation possible to a dedicated and motivated group of patients. This finding
is supported by Rex et al.
15
Success rates depend on appropriate selection.
10
Young male
with an above-average education level, little preprocedural fear, and a personal preference
for procedures without sedation are predictors of a successful sedation-free procedure.
11
However, unpredictable individual anatomical situations can result in inacceptable
discomfort for the patient and worse procedural conditions for the gastroenterologist.
Baudet et al.
16
reported increased complication rates during colonoscopy without the use
of sedation (57 vs. 22%; p<0.001).
MODES OF ANALGO-SEDATION
Sedation guidelines have universally defined levels of sedation, reaching from moderate to
deep sedation.
Deep sedation
is generally achieved using propofol. Its fast start and end of action allows for
a reduced recovery time. Therefore, there is increasing interest in propofol sedation among
gastroenterologists. Unfortunately, its therapeutic range is narrow and enhances the risk of
sedation related cardiopulmonary events. That`s the reason, why in most parts of the US
sedation with propofol by non-anaesthesiologists, is not allowed.
The guidelines in different European states concede the use of propofol to trained nurses
or endoscopists, who are solely responsible for sedation.
17
However, this permission only
concerns moderate, but not deep sedation.
This means deep sedation is more resource intensive because of the need for specialised
sedation staff and extended monitoring.
18
The percentage of colonoscopies with
anaesthesia professional participation is expected to rise from 23.9% in 2007 to 53.4% by
2015, respectively.
19
In view of this dramatic increase, health insurance companies try to
limit payment for sedation delivered by anaesthesia providers.
18
Patients under deep sedation may have impaired spontaneous breathing requiring
assistance to keep an open airway. Closed claims analyses of anaesthesia suggest that
deep sedation carries high risks for serious complications even with well trained staff.
20
Cote
et al. found a percentage of 12,5% sedation related hypoxaemic events during propofol
sedations performed by anaesthesia nurses.
21
In a reviewof over 20.000 reports in the Clinical
Outcomes Research Initiative Database, sedation-related events happened in 1.3% of the
cases.
20
Respiratory (0.75%) and cardiovascular complications (0.49%), and delayed recovery
of psychomotoric function count for the highest rate among all complications. Furthermore,
deeply sedated patients are not able to change position from lateral decubitus to supine
without assistance, which makes it difficult to manoeuvre the patient during procedure.