Preincisional administration of intravenous or subcutaneous infiltration of low-dose ketamine suppresses postoperative pain after appendectomy

Figures & data

Table 1 Patient characteristics and duration of surgery and anesthesia in three groups

Variable	Group KS (n = 30)	Group KI (n = 30)	Group C (n = 30)
Age (years)	30.4 ± 12.0	27.5 ± 8.4	32.9 ± 12.4
Gender (female/male)	14/16	12/18	13/17
Weight (kg)	65.4 ± 3.2	67.4 ± 5.2	64.7 ± 7.2
ASA (I/II)	26/4	25/5	24/6
Duration of surgery (minutes)	54.2 ± 7.4	56.5 ± 6.0	58.2 ± 7.0
Duration of anesthesia (minutes)	66.3 ± 5.5	66.7 ± 5.6	69.0 ± 5.5

Notes: Values are presented as the mean ± standard deviation or number. There were no significant differences between three groups.

Abbreviations: KS, subcutaneous ketamine; KI, intravenous ketamine; C, control; ASA, American Society of Anesthesiologists.

Figure 1 Postoperative visual analog scale scores at 0, 10, 20, and 30 minutes after arrival in the post-anesthesia care unit.

Notes: Data are presented as the mean ± standard deviation. *P < 0.05 versus group C.
Abbreviations: KI, intravenous ketamine; KS, subcutaneous ketamine group; C, control.

Figure 2 Visual analog scale scores at 6, 12, 18, and 24 hours after surgery.

Notes: Data are presented as the mean ± standard deviation. *P < 0.05 versus group C; ^†P < 0.05 versus group KS.
Abbreviations: KI, intravenous ketamine; KS, subcutaneous ketamine group; C, control.

Table 4 Postoperative visual analog scale scores at different time intervals in the three groups

Variable	Group KS (n = 30)	Group KI (n = 30)	Group C (n = 30)	P value
VAS after arrival in PACU (minutes)
VAS 0	1.2 ± 0.4*	1.1 ± 0.6*	4.9 ± 0.8	0.000
VAS 10	0.9 ± 0.9*	0.8 ± 0.5*	4.1 ± 0.8	0.000
VAS 20	0.9 ± 0.5*	1.3 ± 0.7*	3.5 ± 0.7	0.000
VAS 30	1.3 ± 0.7*	1.0 ± 0.3*	3.8 ± 0.5	0.000
Postoperative VAS on ward (hours)
VAS 6	7.3 ± 0.8*	7.2 ± 1.3*	7.9 ± 0.0	0.002
VAS 12	6.4 ± 0.8	5.4 ± 0.9*,†	6.7 ± 0.5	0.000
VAS 18	5.1 ± 1.3	3.5 ± 1.2*,†	5.5 ± 0.6	0.000
VAS 24	4.0 ± 1.5	1.7 ± 0.9*,†	4.4 ± 0.7	0.000

Notes: Data are presented as the mean ± standard deviation.

* P < 0.05 versus group C;

† P < 0.05 versus group KS.

Abbreviations: KS, subcutaneous ketamine; KI, intravenous ketamine; C, control; PACU, post-anesthesia care unit; VAS, visual analog scale score.

Table 2 Postoperative analgesics and antiemetic use and time to tracheal extubation and PACU stay in three groups

Variable	Group KS (n = 30)	Group KI (n = 30)	Group C (n = 30)	P value
Time to first analgesic demand (hours)	2.3 ± 0.7*	2.8 ± 0.9*	1.5 ± 0.5	0.000
Postoperative analgesic requirement (mg)	33.8 ± 15.2*	31.0 ± 8.9*	69.2 ± 30.2	0.000
Duration of PACU stay (minutes)	29.7 ± 2.2	30.4 ± 3.8	29.8 ± 3.3	0.655
Time to tracheal extubation (minutes)	15.1 ± 1.0	15.2 ± 1.1	14.7 ± 1.5	0.275
Postoperative antiemetic requirement (mg)	0.17 ± 0.4	0.13 ± 0.3	0.1 ± 0.3	0.756

Notes: Values are presented as the mean ± standard deviation.

* P < 0.05 versus group C.

Abbreviations: KS, subcutaneous ketamine; KI, intravenous ketamine; C, control; PACU, post-anesthesia care unit.

Table 3 Incidence of adverse effects in the three groups

Variable	Group KS (n = 30)	Group KI (n = 30)	Group C (n = 30)
Nausea	3	1	1
Vomiting	2	3	2
Dizziness	1	1	0

Notes: Values are presented as numbers. There were no significant differences between three groups.

Abbreviations: KS, subcutaneous ketamine; KI, intravenous ketamine; C, control.