107 patients were enrolled and randomly allocated into three groups: Group O1: oxycodone 0.1 mg/kg, Group O2: oxycodone 0.2 mg/kg, or Group F: fentanyl 2 mcg/kg. 2 patients (1 from Group O1 and 1 from Group F) were excluded for analysis because of incomplete data collection. Baseline patient characteristics, including age, gender, body mass index (BMI), and ASA physical status classification distribution of all three groups were comparable (Table 1). In addition, there was no significant difference among these three groups in either surgical time or anesthesia time (Table 1).
Table 1. Patients’ demographic characteristics, surgical and anesthesia time.
|
Group O1 (n=35)
|
Group O2 (n=35)
|
Group F (n=35)
|
Age (years)
|
71.74±4.42
|
70.63±4.96
|
72.46±3.83
|
Male/female (n)
|
17/18
|
18/17
|
15/20
|
BMI (kg/m2)
|
23.45±3.24
|
22.3±2.79
|
22.9±2.98
|
ASA physical status classification, Ⅰ/Ⅱ (n)
|
4/31
|
11/24
|
6/29
|
Surgical time (min)
|
48.46±17.89
|
50.54±28.81
|
48.54±24.23
|
Anesthesia time (min)
|
61.40±18.60
|
63.72±29.72
|
62.43±24.02
|
Values are expressed as mean±standard deviation or number.
BMI = body mass index, ASA = American Society of Anesthesiologists.
As displayed in Table 2a, 2 of 35 patients (5.71%) in Group O1 experienced clinically significant hypotension during the induction period. The incidence of clinically significant hypotension during induction was 11/35 (31.43%) in Group O2 and 13/35 (37.14%) in Group F, respectively. There was significant difference when comparing Groups O1 to Group O2 or F (p<0.05), but not between Groups F and O2. However, we did not find significant difference in the incidence of hypotension among three groups during either the intraoperative period or PACU stay. We observed consistent findings for the intraoperative requirement of vasoactive medication: less ephedrine was administered in Group O1 than F (p<0.05, Table 2b). There was no significant difference in the administration of ephedrine between Groups O1 and O2 or between Groups F and O2. As for the HR change from baseline, there was no significant difference among these three groups during any of the above time periods examined (Table 2c).
Table 2a. The incidence of clinically significant hypotension during induction, the intraoperative period, and PACU stay.
|
Group O1 (n=35)
|
Group O2 (n=35)
|
Group F (n=35)
|
Induction, n (%)
|
2 (5.71%)a,b
|
11 (31.43%)
|
13 (37.14%)
|
Intraoperative, n (%)
|
3 (8.57%)
|
7 (20.00%)
|
10 (28.57%)
|
PACU, n (%)
|
0 (0%)
|
0 (0%)
|
0 (0%)
|
Values are expressed as number (%).
PACU=postoperative anesthesia care unit.
a: significant difference between Groups O1 and O2, P<0.05.
b: significant difference between Groups O1 and F, P<0.05.
Table 2b. The requirement of intraoperative vasoactive medication (ephedrine) for hypotension.
|
Group O1 (n=35)
|
Group O2 (n=35)
|
Group F (n=35)
|
Ephedrine administered (mg)
|
3.09±3.21a
|
5.00±4.72
|
5.66±3.96
|
Values are expressed as mean±standard deviation.
a: significant difference between Groups O1 and F, P<0.05.
Table 2c. Heart rate changes from baseline during induction, the intraoperative period, and PACU stay.
|
Group O1 (n=35)
|
Group O2 (n=35)
|
Group F (n=35)
|
P
|
Induction
|
8.81±9.06
|
13.52±11.10
|
13.96±13.57
|
0.122
|
Intraoperative
|
3.62±9.44
|
13.79±11.85
|
13.41±11.68
|
0.989
|
PACU
|
4.31±9.53
|
4.85±9.52
|
1.64±11.29
|
0.371
|
Values are expressed as mean±standard deviation.
PACU=postoperative anesthesia care unit.
When evaluating for postoperative pain, NRS on extubation was significantly higher for patients in Group F comparing to Group O2 (p<0.05). No difference in NRS on extubation was observed between Group F and Group O1. Similarly, more patients required postoperative rescue analgesics in Group F than Group O2 (p<0.05), whereas there was no difference between Group F and Group O1 (Table 3). However, there was no significant difference in NRS at 0, 2, 6, 24 hours after discharge from PACU among these three groups (Table 3).
Table 3. Postoperative pain control.
|
Group O1 (n=35)
|
Group O2 (n=35)
|
Group F (n=35)
|
NRS on extubation
|
2 (0, 4)
|
0 (0, 3)a
|
2 (0, 6)
|
Rescue analgesics, n (%)
|
2 (5.71%)
|
0 (0%)a
|
7 (20%)
|
NRS on PACU discharge
|
0 (0, 2)
|
0 (0, 2)
|
1 (0, 2)
|
NRS at 2h after discharge
|
0 (0, 2)
|
0 (0, 2)
|
0 (0, 2)
|
NRS at 6h after discharge
|
0 (0, 0)
|
0 (0, 0)
|
0 (0, 0)
|
NRS at 24h after discharge
|
0 (0, 0)
|
0 (0, 0)
|
0 (0, 0)
|
Values are expressed as number (%) or median (ranges).
NRS=Numeric rating scale, PACU=postoperative anesthesia care unit.
a: significant difference between Groups O2 and F, P<0.05.
The recovery time of spontaneous breathing, the emergence time and PACU length of stay in Group O2 were all longer comparing to either Group O1 or F (p<0.05). Upon discharge from PACU, the RSS in Group O2 was significantly higher than Group O1 or F (p<0.05, Table 4).
Table 4. Recovery time and sedation level during PACU stay.
|
Group O1
(n=35)
|
Group O2
(n=35)
|
Group F
(n=35)
|
Recovery time of spontaneous breathing (min)
|
13.03±5.10
|
18.66±5.47a,b
|
12.51±8.28
|
Emergence time (min)
|
17.09±4.29
|
25.77±10.07a,b
|
18.29±7.27
|
PACU length of stay (min)
|
32.94±6.43
|
42.80±11.64a,b
|
35.09±8.75
|
RSS on PACU discharge
|
2 (2, 2)
|
3 (2, 3)a,b
|
2 (2, 2)
|
Values are expressed as mean±standard deviation or median (ranges).
PACU= postoperative anesthesia care unit, RSS=Ramsay sedation score.
a: significant difference between Group O2 and Group O1, P<0.05.
b: significant difference between Group O2 and Group F, P<0.05.
With regard to perioperative adverse effects, the incidence of hypoxia events in PACU was significantly higher in Group O2 than either Group O1 or F (p<0.05). There was no significant difference among these three groups in coughing during induction or postoperative nausea/vomiting (Table 5).
Table 5. The incidence of perioperative adverse events.
|
Group O1
(n=35)
|
Group O2
(n=35)
|
Group F
(n=35)
|
Hypoxia in PACU, n (%)
|
2 (5.71%)
|
9 (25.71%)a,b
|
2 (5.71%)
|
Coughing during induction, n (%)
|
1 (2.86%)
|
2 (5.71%)
|
2 (5.71%)
|
Nausea or vomiting, n (%)
|
0 (0%)
|
4 (11.43%)
|
0 (0%)
|
Values are expressed as number (%).
PACU= postoperative anesthesia care unit.
a: significant difference between Group O2 and Group O1, P<0.05.
b: significant difference between Group O2 and Group F, P<0.05.