Table 2.

Univariate analysis of predictive factors for pain within 72 h after OG.

	Postoperative NRS at 24 h	Postoperative NRS at 48 h	Postoperative NRS at 72 h
Predictors	P value	P value	P value
Age, years	0.308	0.509	0.917
Gender, n (%)	0.149	0.492	0.228
BMI, kg/m2	0.928	0.009*	0.03*
Diabetes	0.241	0.015*	0.041*
Hypertension	0.985	0.592	0.047*
Previous abdominal surgery	0.979	0.469	0.396
Pre-operative hemoglobin, g/L	0.547	0.520	0.018*
Pre-operative albumin, g/L	0.872	0.838	0.603
Carcinoembryonic antigen	0.581	0.537	0.185
Pre-operative chemo- or radio-therapy	0.841	0.594	0.175
Tumor location	0.179	0.325	0.792
Tumor size, cm	0.279	0.332	0.815
Lauren's histology	0.457	0.040*	0.144
Pathological grading	0.838	0.752	0.820
Lymph node metastasis	0.512	0.953	0.942
Depth of invasion	0.535	0.715	0.210
Distant metastasis	0.108	0.417	0.049*
Lymphovascular invasion	0.541	0.839	0.841
Perineural invasion	0.127	0.570	0.789
AJCC TNM stage	0.028*	0.817	0.622
ASA score	0.744	0.392	0.603
Total gastrectomy	0.041*	0.783	0.353
Duration of operation, min	0.610	0.034*	0.152
Intraoperative blood loss, ml	0.147	0.045*	0.742
Intraoperative transfusion, ml	0.250	0.509	0.005*
Postoperative PCA	0.472	0.367	0.450
Preventive analgesia	0.419	0.458	0.951
Intraoperative fentanyl dosage, mg	0.280	0.860	0.288
Intraoperative dexmedetomidine dosage, mg	0.593	0.865	0.311

ASA Classification, American Society of Anesthesiologists physical status; BMI, body mass index; NRS, Numerical Rating Scale; AJCC, American Joint Committee on Cancer; TNM, Tumor Node Metastasis; PCA, Patient-controlled intravenous analgesia.

*P < 0.05.