The Effects of Body Mass Index on the Use of Patient-Controlled Intravenous Analgesia After Open Gastrointestinal Tumor Surgery: A Retrospective Analysis

Figures & data

Table 1 Characteristics of Patients

Group		A	B	C	D	E	F	p value
		BMI < 18.5 kg/m^2	18.5 kg/m^2 ≤BMI<22kg/m^2	22 kg/m^2 ≤ BMI < 24 kg/m^2	24 kg/m^2 ≤ BMI < 26 kg/m^2	26 kg/m^2 ≤ BMI < 28 kg/m^2	BMI ≥ 28 kg/m^2
Gender (%)	Male	55.2% (16/29)	58.1%(72/124)	62.6% (62/99)	59.4% (41/69)	71.7% (33/46)	69.6% (16/23)	0.556
	Female	44.8% (13/29)	41.9% (52/124)	37.4% (37/99)	40.6% (28/69	28.3% (13/46)	30.4% (7/23)
Age (years)	Mean ± SD	57.55 ± 17.30	58.06 ± 11.56	56.42 ± 12.35	57.80 ± 9.87	57.96 ± 10.70	55.17 ± 12.84	0.88
	< 60	37.9% (11/29)	50.0% (62/124)	56.6% (56/99)	55.1% (38/69)	52.2% (24/46)	52.2% (12/23)	0.61
	≧ 60	62.1% (18/29)	50.0% (62/124)	43.4% (43/99)	44.9% (31/69)	47.8% (22/46)	47.8% (11/23)
Height (cm)	Mean ± SD	161.79 ± 6.56	163.40 ± 8.08	162.75 ± 7.71	162.01 ± 8.06	162.13 ± 8.15	161.70± 11.94	0.806
Weight (kg)	Mean ± SD	45.79 ± 4.31 #b, #c, #d, #e, #f	54.73 ± 5.66 #a, #c, #d, #e, #f	61.05 ± 5.93 #a, #b, #d, #e, #f	65.46 ± 6.89 #a, #b, #c, #e, #f	70.77 ± 7.08 #a, #b, #c, #d, #f	78.09 ± 9.77 #a, #b, #c, #d, #e	0*
Tumor location	Stomach	44.8% (13/29)	48.4% (60/124)	43.4% (43/99)	31.9% (22/69)	54.3% (25/46)	34.8% (8/23)	0.244
	Colon	20.7% (6/29)	17.7% (22/124)	27.3% (27/99)	23.2% (16/69)	13.0% (6/46)	17.4% (4/23)
	Rectum	34.5% (10/29)	33.9% (42/124)	29.3% (29/99)	44.9% (31/69)	32.6% (15/46)	47.8% (11/23)
Hypertension		3.4% (1/29)	6.5% (8/116)	11.1% (11/99)	18.8% (56/69)	21.7% (10/46)	21.7% (5/23)	0.012*
Diabetes		13.8% (4/29)	3.2% (4/124)	4.0% (4/99)	5.8% (4/69)	6.5% (3/46)	8.7% (2/23)	0.292

Notes: A: BMI < 18.5 kg/m²; B: 18.5 kg/m² ≤ BMI < 22 kg/m²; C: 22 kg/m² ≤ BMI < 24 kg/m²; D: 24 kg/m² ≤ BMI < 26 kg/m²; E: 26 kg/m² ≤ BMI < 28 kg/m²; F: BMI ≥ 28 kg/m². *There were significant differences among groups (p < 0.05). #a/#b/#c/#d/#e/#f: The difference between this group and Group A/B/C/D/E/F was statistically significant (p < 0.05).

Abbreviation: SD, standard deviation.

Figure 1 Characteristics of patients (A) Number of different genders in each subgroup. (B) Percentage of different genders in each subgroup. (C) Age of patients. (D) Number of different age stages in each subgroup. (E) Percentage of different age stages in each subgroup. (F) Height of patients. (G) Weight of patients. (H) Number of different tumor sites in each subgroup. (I) Percentage of different tumor sites in each subgroup. (J) Number of complications in each subgroup. (K) Percentage of complications in each subgroup.

Notes: A: group A (BMI < 18.5kg/m²); B: group B (18.5kg/m² ≤ BMI < 22kg/m²); C: group C (22kg/m² ≤ BMI < 24kg/m²); D: group D (24kg/m² ≤ BMI < 26kg/m²); E: group E (26kg/m² ≤ BMI < 28kg/m²); F: group F (BMI ≥ 28kg/m²). ^#The difference of subgroups was statistically significant (p < 0.05).

Table 2 Duration of Operation and Use of Analgesics

Group			A	B	C	D	E	F	p value
			BMI < 18.5 kg/m^2	18.5 kg/m^2 ≤BMI<22kg/m^2	22 kg/m^2 ≤ BMI < 24 kg/m^2	24 kg/m^2 ≤ BMI < 26 kg/m^2	26 kg/m^2 ≤ BMI < 28 kg/m^2	BMI ≥ 28 kg/m^2
Time of operation (h)			2.98 ± 0.99	2.81 ± 1.23	2.95 ± 1.22	2.90 ± 1.07	3.25 ± 1.37	3.16 ± 1.18	0.364
Analgesic	Intraoperative dosage of sufentanil	Mean ± SD	38.90 ± 14.36	38.51 ± 12.57	39.52 ± 13.43	41.87 ± 15.43	46.48 ± 18.94	49.33 ± 20.02	0.01*
	Use of other analgesics during operation (%)	Parecoxib	37.9% (11/29)	36.3% (45/124)	36.4% (36/99)	33.3% (23/69)	30.4% (14/46)	47.8% (11/23)	0.808
		Flurbiprofen axetil	58.6% (17/29)	48.4% (60/124)	49.5% (49/99)	40.6% (28/69)	45.7% (21/46)	43.5% (10/23)	0.673
		Tramadol	0.0% (0/29)	4.0% (5/124)	3.0% (3/99)	5.8% (4/69)	4.3% (2/46)	0.0% (0/23)	0.678
		Dezocine	3.4% (0/29)	12.1% (15/124)	12.1% (12/99)	20.3% (14/69)	19.6% (9/46)	8.7% (2/23)	0.461
	Use of additional analgesics in the postoperative ward (%)	None	27.6%(8/29)	29.8% (37/124)	43.4% (43/99)	42.0% (29/69)	30.4% (14/46)	26.1% (6/23)	0.539
		Sometimes (≤ twice)	10.3% (3/29)	12.9% (16/124)	11.1% (11/99)	10.1% (7/69)	8.7% (4/46)	13.0% (3/23)
		Frequently (> twice)	62.1% (18/29)	57.3% (71/124)	45.5% (45/99)	47.8% (33/69)	60.9% (28/46)	60.9% (14/23)

Notes: A: BMI < 18.5 kg/m2; B: 18.5 kg/m² ≤ BMI < 22 kg/m²; C: 22 kg/m² ≤ BMI < 24 kg/m²; D: 24 kg/m² ≤ BMI < 26 kg/m²; E: 26 kg/m² ≤ BMI < 28 kg/m²; F: BMI ≥ 28 kg/m². *There were significant differences among groups (p < 0.05).

Abbreviation: SD, standard deviation.

Figure 2 Duration of operation and use of analgesics. (A) Operation time of the patient (h). (B) Intraoperative use of sufentanil (ug). (C) The number of other analgesics used during the operation. (D) Percentage of other analgesics used during the operation. (E) The number of additional analgesics used after surgery. (F) Percentage of additional analgesics used after surgery.

Notes: A: group A (BMI < 18.5kg/m²); B: group B (18.5kg/m² ≤ BMI < 22kg/m²); C: group C (22kg/m² ≤ BMI < 24kg/m²); D: group D (24kg/m² ≤ BMI < 26kg/m²); E: group E (26kg/m² ≤ BMI < 28kg/m²); F: group F (BMI ≥ 28kg/m²).

Table 3 VAS Score After Surgery

Group		A	B	C	D	E	F	p value
		BMI < 18.5 kg/m^2	18.5 kg/m^2 ≤BMI<22kg/m^2	22 kg/m^2 ≤ BMI < 24 kg/m^2	24 kg/m^2 ≤ BMI < 26 kg/m^2	26 kg/m^2 ≤ BMI < 28 kg/m^2	BMI ≥ 28 kg/m^2
At rest 24 h after surgery	Mean ± SD	1.83 ± 1.56 #b	1.10 ± 0.98 #a	1.49 ± 1.06	1.18 ± 0.84	1.39 ± 1.02	1.52 ± 1.39	0.004*
	VAS ≤ 3	93.1% (27/29)	97.6% (121/124)	96.0% (95/99)	100.0% (69/69)	97.8% (45/46)	100.0% (23/23)	0.358
	VAS > 3	6.9% (2/29)	2.4% (3/124)	4.0% (4/99)	0.0% (0/69)	2.2% (1/46)	0.0% (0/23)
Be active 24 h after surgery	Mean ± SD	3.17 ± 1.51	2.64 ± 1.34	2.96 ± 1.31	2.84 ±1.18	2.93 ±1.12	3.00 ± 1.17	0.256
	VAS ≤ 3	62.1% (18/29)	78.2% (97/124)	67.7% (67/99)	73.9% (51/69)	73.9% (34/46)	65.3% (15/23)	0.361
	VAS > 3	37.9% (11/29)	21.8% (27/124)	32.3% (32/99)	26.1% (18/69)	26.1% (12/46)	34.8% (8/23)
At rest 48 h after surgery	Mean ± SD	0.72 ± 1.10	0.56 ± 0.76	0.60 ± 0.77	0.48 ± 0.63	0.59 ± 0.72	0.61 ± 0.72	0.796
	VAS ≤ 3	96.6% (28/29)	99.2% (123/124)	99.0% (98/99)	100.0% (69/69)	100.0% (46/46)	100.0% (23/23)	0.568
	VAS > 3	3.4% (1/29)	0.8% (1/124)	1.0% (1/99)	0.0% (0/69)	0.0% (0/46)	0.0% (0/23)
Be active 48 h after surgery	Mean ± SD	1.83 ± 1.34	1.70 ± 0.94 #c	2.17 ± 1.19 #b	1.71 ± 0.97	1.89 ± 0.95	1.78 ± 0.80	0.021*
	VAS ≤ 3	96.6% (28/29)	96.0% (119/124)	88.9% (88/99)	94.2% (65/69)	93.5% (43/46)	95.7% (22/23)	0.364
	VAS > 3	3.4% (1/29)	4.0% (5/124)	11.1% (11/99)	5.8% (4/69)	6.5% (3/46)	4.3% (1/23)

Notes: A: BMI < 18.5 kg/m²; B: 18.5 kg/m² ≤ BMI < 22 kg/m²; C: 22 kg/m² ≤ BMI < 24 kg/m²; D: 24 kg/m² ≤ BMI < 26 kg/m²; E: 26 kg/m² ≤ BMI < 28 kg/m²; F: BMI ≥ 28 kg/m². *There were significant differences among groups (p < 0.05). #a/#b/#c: The difference between this group and Group A/B/C was statistically significant (p < 0.05).

Abbreviation: SD, standard deviation.

Figure 3 Postoperative VAS. (A) VAS scores at 24 hours and 48 hours after surgery. (B) The number of moderate to severe postoperative pain. (C) Percentage of moderate to severe postoperative pain.

Notes: A: group A (BMI < 18.5kg/m²); B: group B (18.5kg/m² ≤ BMI < 22kg/m²); C: group C (22kg/m² ≤ BMI < 24kg/m²); D: group D (24kg/m² ≤ BMI < 26kg/m²); E: group E (26kg/m² ≤ BMI < 28kg/m²); F: group F (BMI ≥ 28kg/m²). ^#The difference of subgroups was statistically significant (p < 0.05).

Table 4 Postoperative Adverse Reactions

Group			A	B	C	D	E	F	p value
			BMI < 18.5 kg/m^2	18.5 kg/m^2 ≤BMI<22kg/m^2	22 kg/m^2 ≤ BMI < 24 kg/m^2	24 kg/m^2 ≤ BMI < 26 kg/m^2	26 kg/m^2 ≤ BMI < 28 kg/m^2	BMI ≥ 28 kg/m^2
24 h after surgery	Dizzy	Mild	6.9% (2/29)	8.3% (10/121)	5.2% (5/97)	10.1% (7/69)	4.5% (2/44)	0.0% (0/23)	0.554
		Moderate	0.0% (0/29)	6.6% (8/121)	4.1% (4/97)	2.9% (2/69)	6.8% (3/44)	13.0% (3/23)
		Severe	3.4% (1/29)	1.7% (2/121)	5.2% (5/97)	1.4% (1/69)	2.3% (1/44)	0.0% (0/23)
	Nausea		24.1% (7/29)	10.5% (13/124)	7.1% (7/99)	8.7% (6/69)	6.5% (3/46)	8.7% (2/23)	0.137
	Vomit		10.3% (3/29)	3.2% (4/124)	2.0% (2/99)	1.4% (1/69)	0.0% (0/46)	0.0% (0/23)	0.009*
48 h after surgery	Dizzy	Mild	0.0% (0/29)	0.0% (0/121)	0.0% (0/98)	0.0% (0/69)	2.2% (1/45)	4.3% (1/23)	0.23
		Moderate	0.0% (0/29)	0.8% (1/121)	0.0% (0/98)	0.0% (0/69)	0.0% (0/45)	0.0% (0/23)
		Severe	0.0% (0/29)	0.0% (0/121)	0.0% (0/98)	0.0% (0/69)	0.0% (0/45)	0.0% (0/23)
	Sick		3.4% (1/29)	4.8% (6/124)	4.0% (4/99)	2.9% (2/69)	0.0% (0/45)	8.7% (2/23)	0.582
	Vomit		0.0% (0/29)	0.8% (1/124)	2.0% (2/99)	1.4% (1/69)	0.0% (0/45)	4.3% (1/23)	0.65

Notes: A: BMI < 18.5 kg/m²; B: 18.5 kg/m² ≤ BMI < 22 kg/m²; C: 22 kg/m² ≤ BMI < 24 kg/m²; D: 24 kg/m² ≤ BMI < 26 kg/m²; E: 26 kg/m² ≤ BMI < 28 kg/m²; F: BMI ≥ 28 kg/m². *There were significant differences among groups (p < 0.05).

Abbreviation: SD, standard deviation.

Table 5 Regression Analysis of Postoperative Vomiting

		OR	95% CI	p value
Gender	Male	0.526	0.526–5.371	0.588
	Female
Age (years old)	Mean	1.158	1.003–1.337	0.045*
Height (cm)		0.642	0.216–1.905	0.424
Weight (kg)		1.875	0.382–9.215	0.439
BMI (kg/m2)		0.119	0.002–8.689	0.331
Tumor location	Stomach	1.205	0.350–4.145	0.767
	Colon
	Rectum
Hypertension				0.997
Diabetes				0.998
Time of operation (h)		0.479	0.144–1.594	0.230
Intraoperative sufentanil dosage (ug)		1.031	0.943–1.128	0.498
Use of other analgesics during operation	Parecoxib			1
	Flurbiprofen axetil			1
	Tramadol			0.998
	Dezocine			1
Postoperative VAS score	At rest 24 h after surgery	4.284	0.623–29.481	0.139
	Be active 24 h after surgery	0.69	0.161–2.949	0.616
	At rest 48 h after surgery	0.103	0.01–1.039	0.054
	Be active 48 h after surgery	0.735	0.167–3.234	0.684

Note: *The results were statistically significant (p < 0.05).

Figure 4 Postoperative adverse reactions. (A) The number of adverse reaction. (B) The percentage of adverse reaction.

Notes: A: group A (BMI < 18.5kg/m²); B: group B (18.5kg/m² ≤ BMI < 22kg/m²); C: group C (22kg/m² ≤ BMI < 24kg/m²); D: group D (24kg/m² ≤ BMI < 26kg/m²); E: group E (26kg/m² ≤ BMI < 28kg/m²); F: group F (BMI ≥ 28kg/m²). ^#The difference of subgroups was statistically significant (p < 0.05).

Figure 5 Time from the end of the operation to activities and postoperative quality of life. (A) Time to exhaust to the anus (h). (B) Time to drink water (h). (C) Time to get out of bed (h). (D) Time to pull out the urine tube (h). (E) Time to pull out the abdominal drainage tube (h). (F) Time to pull out the gastric tube (h). (G) Postoperative length of stay (d). (H) Postoperative quality of life.

Notes: A: group A (BMI < 18.5kg/m²); B: group B (18.5kg/m² ≤ BMI < 22kg/m²); C: group C (22kg/m² ≤ BMI < 24kg/m²); D: group D (24kg/m² ≤ BMI < 26kg/m²); E: group E (26kg/m² ≤ BMI < 28kg/m²); F: group F (BMI ≥ 28kg/m²).

Table 6 Postoperative Activity and Quality of Life Assessments

Group		A	B	C	D	E	F	p value
		BMI <18.5 kg/m^2	18.5 kg/m^2 ≤BMI <22 kg/m^2	22 kg/m^2 ≤BMI <24 kg/m^2	24 kg/m^2 ≤ BMI <26 kg/m^2	26 kg/m^2 ≤ BMI<28 kg/m^2	BMI ≥ 28 kg/m^2
The time from the end of the operation to various activities	Passage gas anus (h)	68.13 ± 25.66	72.81 ± 33.48	66.55 ± 27.99	63.63 ± 26.62	71.50 ± 40.24	64.98 ± 29.76	0.437
	Drinking (h)	56.09 ± 36.27	59.77 ± 36.27	59.68 ± 33.28	55.45 ± 31.42	63.55 ± 45.63	56.45 ± 35.94	0.88
	Getting out of bed(h)	58.89 ± 26.20	51.03 ± 24.14	51.76 ± 20.56	52.31 ± 19.08	54.46 ± 24.67	57.09 ± 22.06	0.532
	Pulling out the urine tube(h)	87.51 ± 41.61	94.04 ± 49.28	86.22 ± 39.05	104.18 ± 39.44	103.80 ± 49.07	102.93 ± 44.79	0.094
	Pulling out the abdominal drainage tube (h)	163.03 ± 71.43	137.34 ± 56.57	142.33 ± 75.53	135.86 ± 44.30	162.52 ± 88.02	137.96 ± 57.67	0.207
	Pulling out the gastric tube(h)	79.96 ± 46.59	70.17 ± 54.31	62.73 ± 44.06	65.62 ± 42.35	85.79 ± 54.94	79.41 ± 51.55	0.48
Postoperative length of stay(d)		8.03 ± 2.77	7.57 ± 2.81	7.30 ± 2.48	7.17 ± 2.10	7.89 ± 3.39	9.30 ± 4.70	0.101
Postoperative quality of life		14.43 ± 5.28	12.33 ± 3.37	11.63 ± 3.02	12.78 ± 4.13	12.56 ± 3.20	14.00 ± 6.49	0.146

Notes: A: BMI < 18.5 kg/m²; B: 18.5 kg/m² ≤ BMI < 22 kg/m²; C: 22 kg/m² ≤ BMI < 24 kg/m²; D: 24 kg/m² ≤ BMI < 26 kg/m²; E: 26 kg/m² ≤ BMI < 28 kg/m²; F: BMI ≥ 28 kg/m².