Results:
Fig.1 showed the study flow diagram. There was no statistical significance between characteristics of patients such as age, gender, BMI, or preoperative laboratory values (Table 1).
Propofol EC50 and its 95% confidence interval for gastrointestinal endoscopy in elderly patients were 1.71 (1.15-2.27) μg/mL in SK0.5 group, 2.45 (1.85-3.05) μg/mL in SK0.25 group and 3.69 (2.59-4.78) μg/mL in control group respectively (P < 0.05) (Table 2). EC50 of propofol in SK0.5 group and SK0.25 group was statistically significantly decreased compared with control group (P < 0.05). Furthermore, there was statistically significant difference between SK0.5 group and SK0.25 group (P < 0.05). The propofol TCI concentrations for consecutive patients and their responses to the gastrointestinal endoscopy are shown in Fig.2-4.
The average percent change to baseline MBP was -19.7 (7.55), -15.2 (7.14) and -10.1 (6.73) with P <0.001, and average percent change to baseline HR was -7.30 (8.39), -5.41 (9.68) and -3.75 (7.30) withP = 0.275 in the control group, the SK0.25 group and the SK0.5 group, respectively (Table 3). MBP values in the SK0.25 group and the SK0.5 group decreased significantly less than those in the control group (P <0.05). Figure 5, 6 shows the time course of percent change to baseline in MBP and HR. Recovery time in the control group was significantly longer than those in the SK0.25 group and the SK0.5 group (P <0.001). There was no statistical significance between groups for patient satisfaction and gastroenterologist satisfaction (P >0.05) (Table 3).
The study was completed without any significant clinical complication. Major complications included hypotension or/and bradycardia (3 patients in control group), respiratory depression (1 patient in control group), PONV (1 patient in control group), and eye tremor (1 patient each for the SK0.25 group and the SK0.5 group). There was no psychotomimetic effects in our study.