Measurements
Baseline values of MBP and HR were defined as the lowest of the three
measurements during 3 min interval just before TCI propofol. MBP and HR
were measured and recorded at the designated time points and at a 3-min
interval duration of endoscopic procedure. The designated time points:
T0 = baseline values; T1 = the target
concentration achieved after TCI propofol; T2= 3 min
after esketamine injection; T3 = at scope intubation and
T4-x = by 3-min intervals during the procedure.
Perioperative anaesthesia related adverse events, such as bradycardia,
hypotension, frequency of respiratory depression, nystagmus, mental
symptoms, and postoperative nausea and vomiting (PONV) were also
recorded. TCI propofol was maintained till the removal of the
colonoscopy. Recovery time was defined as the time from discontinuing
propofol to Observer’s Assessment of Alertness/Sedation scale (OAA/S) =
5 (responds readily to name spoken in normal tone). The endoscopic time
were also recorded.
The patient’s satisfaction with the procedure was assessed 45 min after
endoscopic procedure as: 4, no discomfort; 3, slightly uncomfortable; 2,
extremely uncomfortable; 1, unacceptable. The gastroenterologist’s
satisfaction (4 = excellent, 3 = good, 2 = fair, 1 = poor) was assessed
immediately after endoscopic procedure [15].
The primary endpoint was the median effective concentration
(ED50) of propofol with different doses of esketamine
during gastrointestinal endoscopy in elderly patients. The secondary
endpoint was to compare the change of haemodynamics among three groups:
the average percent change to baseline in MBP and HR. We defined that
percent change at the designated time points = (MBPT1-x– MBPT0)/ MBPT0* 100.