To explore the correlation between preoperative blood cholesterol level and poorly controlled postoperative pain in enhanced recovery after surgery (ERAS) patients with colorectal cancer.

From October 2016 to October 2018, data of one hundred and twenty-one patients with colorectal cancer who underwent ERAS in the First Affiliated Hospital of Sun Yat-sen University were retrospectively analyzed. According to preoperative serum total cholesterol level, the patients were divided into low cholesterol group (for female <4.35 mmol/L, for male <4.10 mmol/L), medium cholesterol group (for female 4.35-5.30 mmol/L, for male 4.10-4.70 mmol/L), and high cholesterol group (for female >5.30 mmol/L, for male >4.70 mmol/L). The differences of NRS pain score and the incidence of poor pain control (NRS≥5) were compared among the three groups at 0-3 days after operation.

The incidence of postoperative pain and poor pain control were 98.3% (119/121) and 12.4% (15/121), respectively. The incidence of poor pain control in low cholesterol group was 21.1% (8/38), which was significantly higher than 6.4% (3/47) in medium cholesterol group and 11.4% (4/35) in high cholesterol group (χ²=9.458, P=0.003). There was no significant difference in pain NRS scores among the three groups at 0-3 days after operation (χ²=0.135, P=0.405). Logistic regression analysis showed that preoperative serum total cholesterol level was negatively correlated with the incidence of postoperative pain control (β= -0.212, OR=0.921, P<0.05).

Low blood cholesterol level may increase the risk of poor pain control after operation, which provides reference for personalized pain control management after ERAS for colorectal cancer.