

14
Chapter 1
Chapter 8
provides a description of pharmacodynamics, systemic effects, and possible
applications of dexmedetomidine.
24
In
chapter 9
we compared in a randomised controlled
study the satisfaction and safety of a group of patients receiving moderate sedation with
dexmedetomidine with a second group sedated with propofol.
25
Our study focussed
on elective endoscopic oesophageal procedures for treatment of Barrett’s oesophagus.
These procedures require patients who are sedated, but easily arousable to provide an
excellent endoscopic view of the oesophagus. Thus, we tended to a level of sedation -
using the observer’s assessment of alertness/sedation scale (OAA/S) - between 2 and 4,
meaning that patients show maximal lethargic response to their name spoken in normal
tone.
26
Patients were constantly monitored for HR, SpO
2
, ECG, etCO
2
, NIBP, and non-invasive
cardiac output (NICO). After the procedure, patients rated their satisfaction level using a
validated questionnaire modified from the patient satisfaction with sedation instrument
(PSSI).
27
Endoscopists were asked about their experience using the corresponding clinician
satisfaction with sedation instrument (CSSI) score.
27
Chapter 10
focuses on another promising drug for moderate sedation: remifentanil, an
opioid with a rapid begin within 30-60 s, peak effect within 2.5 min, and half-life of 8-10
min. Remifentanil is metabolised by non-specific esterases resulting in a rapid systemic
elimination. This is useful especially in situations making a predictable termination of its
effect necessary. Lim et al. showed that remifentanil slowly titrated with a target controlled
infusion (TCI) system successfully suppressed the coughing reflex during intubation.
28
Intubation is a procedure that provokes irritation of the complete airway system in almost
the same manner as bronchoscopy. Therefore, we used these findings to develop a concept
for moderate sedation during bronchoscopy and bronchial thermoplasty (BT) consisting of
remifentanil TCI combined with propofol TCI.
29
BT is a novel bronchoscopic treatment for patients with moderate-to-severe asthma; it has
been shown to improve quality of life and to reduce asthma symptoms and exacerbation
rates.
30
A complete BT treatment consists of 3 consecutive bronchoscopic procedures
during which airways of the left lower lobe, right lower lobe, and finally both upper lobes
are treated with radiofrequency.
We performed a prospective observational cohort study including 32 BT procedures in
severe asthma patients. After each procedure, patients were requested to rate their overall
satisfaction with sedation on a visual analogue scale (VAS). Similarly, bronchoscopists were
asked to rate patients` cooperation and tolerance. All sedation-related events and the
number of performed radiofrequency activations on the airway were registered.