Effect of remote ischemic preconditioning in patients undergoing laparoscopic colorectal cancer surgery: a randomized controlled trial

Figures & data

Figure 1. CONSORT diagram for the trial. CONSORT: CONsolidated Standards Of Reporting Trials; ASA: American Society of Anesthesiologists; RIPC: remote ischemic preconditioning.

Table 1. Demographic data for the eighty participants.

	Control (n = 40)	RIPC (n = 40)	χ^2/F/U	p
Sex (M/F)	24/16	27/13	0.487	0.485
Age (years)	55.0 (49.0, 61.8)	55.5 (52.3, 58.0)	764.000	0.728
BMI (kg/m^2)	23.4 ± 2.3	23.8 ± 3.4	0.462	0.499
ASA fitness grade
I	5 (12.5)	6 (15.0)	0.105	0.745
II	25 (62.5)	23 (57.5)	0.208	0.648
III	10 (25.0)	11 (27.5)	0.065	0.799
Past medical history
Smoking	18 (45.0)	15 (37.5)	0.464	0.496
Hypertension	8 (20.0)	11 (27.5)	0.621	0.431
Diabetes	5 (12.5)	7 (17.5)	0.392	0.531
COPD	3 (7.5)	4 (10.0)	0.157	1.000^♣
Chronic gastrointestinal diseases	6 (15.0)	5 (12.5)	0.105	0.745
Operation
Right hemicolectomy	15 (37.5)	18 (45.0)	0.464	0.496
Subtotal colectomy	4 (10.0)	3 (7.5)	0.157	1.000^♣
Anterior resection	18 (45.0)	17 (42.5)	0.051	1.000
Abdominoperineal resection	3 (7.5)	2 (5.0)	0.213	1.000^♣
Pre-operative blood biochemical data
WBC (10^9/L)	5.7 ± 1.7	6.2 ± 1.9	1.073	0.303
Neutrophil granulocyte percentage (%)	59.1 ± 8.2	62.1 ± 9.6	2.319	0.132
TNF-α (pg/ml)	83.2 ± 10.6	81.8 ± 11.0	0.313	0.578
CRP (mg/L)	4.4 ± 2.2	3.8 ± 1.4	2.271	0.140
Duration of operation (min)	205.0 (141.3, 287.5)	206.5(166.3, 250.0)	782.500	0.866
Total infusion volume (L)^♠	2.5 (2.0, 3.0)	2.5 (2.0, 2.5)	687.500	0.258
Sodium bicarbonate input (ml)	70.0 (0.0, 100.0)	80.0 (0.0, 100.0)	766.000	0.729
Urine output (ml)	400.0 (300.0, 675.0)	500.0 (300.0, 775.0)	784.000	0.876
Estimate blood loss (ml)	120.0 (90.0, 140.0)	110.0 (110.0, 140.0)	706.500	0.361
Blood transfusion patients	5 (12.5)	4 (10.0)	0.125	1.000^♣
Patients with vasopressors	12 (30.0)	7 (17.5)	1.726	0.189
Patients with furosemide	3 (7.5)	6 (15.0)	1.127	0.481^♣
Delayed emergence from anesthesia^♥	7 (17.5)	5 (12.5)	0.392	0.755^♣
Underwent unplanned enterostomy	3 (7.5)	5 (12.5)	0.556	0.712^♣

RIPC: remote ischemic preconditioning; BMI: body mass index; ASA: American Society of Anesthesiologists; COPD: chronic obstructive pulmonary disease; WBC: white blood cell; TNF-α: tumor necrosis factor-α; CRP: C-reactive protein.

Data are mean ± SD, median (range), or number (%).

^♠The intraoperative fluid replacement protocol was 1:1 of compound sodium chloride and polygelatin peptide.

^♥Delayed anesthesia recovery was defined as more than 90 min from the time of general anesthesia withdrawal to when the eyes could be awakened or opened voluntarily.

^♣Fisher exact test.

Table 2. Results of intention-to-treat analysis.

	Control (n = 40)	RIPC (n = 40)	χ^2/U	p
Time to gastrointestinal tolerance (days)	6.0 (4.0, 8.8)	5.0 (3.0, 7.0)	661.000	0.178
Time to diet (days)	4.0 (2.0, 6.0)	3.0 (2.0, 5.0)	687.000	0.269
Time to flatus (days)	2.0 (2.0, 5.0)	2.0 (2.0, 4.0)	699.000	0.313
Time to stool (days)	5.0 (4.0, 7.8)	4.0 (3.0, 6.0)	574.000	0.027
Post-operative duration of hospital stay (days)	9.0 (7.0, 10.0)	9.0 (8.0, 9.8)	768.000	0.753
NGT required	10 (25.0)	7 (17.5)	0.672	0.412
IVN required	3 (7.5)	4 (10.0)	0.157	1.000^♣
Incidence of PPOI	12 (30.0)	6 (15.0)	2.581	0.108
Post-operative complications
Nausea or vomiting	3 (7.5)	1 (2.5)	1.053	0.615^♣
Abdominal distension	3 (7.5)	2 (5.0)	0.213	1.000^♣
Anastomotic leakage	1 (2.5)	0	1.013	1.000^♣
New pulmonary infection^♦	2 (5.0)	1 (2.5)	0.346	1.000^♣
Poor wound healing	2 (5.0)	3 (7.5)	0.213	1.000^♣
Cognitive dysfunction	4 (10.0)	3 (7.5)	0.157	1.000^♣
Unplanned reoperation	1 (2.5)	1 (2.5)	0.000	1.000^♣
30-day readmission rate	0	0	–	–

NGT: nasogastric tube; IVN: intravenous nutrition; PPOI: prolonged post-operative ileus.

Data are mean ± SD, median (range), or number (%).

^♦New pulmonary infection was diagnosed by CT.

^♣Fisher exact test.

Figure 2. Blood biochemical data. The midpoints and error bars showed mean and SDs. RIPC: remote ischemic preconditioning; WBC: white blood cell; TNF-α: tumor necrosis factor-α; CRP: C-reactive protein; D0: pre-operative day 1; D1: post-operative day 1; D3: post-operative day 3; D5: post-operative day 5. Repeated measures analysis of variance was used and multiple comparisons were analyzed after Bonferroni correction and compared with the control group, ^♯p < 0.013.

Figure 3. Receiver operating characteristic curves of the TNF-α and CRP levels between the control and RIPC groups. TNF-α: tumor necrosis factor-α; CRP: C-reactive protein; D1: post-operative day 1; D3: post-operative day 3.