Pain perception after colorectal surgery: A propensity score matched prospective cohort study

IntroductionMinimally invasive approach for colorectal surgery promotes functional recovery and reduces length of stay without compromising oncological outcome (1-3).Enhanced recovery after surgery (ERAS) pathways advocate minimally invasive surgery to decrease surgical stress, morbidity, length of stay and costs (4).ERAS care protocols including multimodal pain management strategies aim to facilitate recovery by an opioidsparing attitude to avoid opioid-related side effects (5).Epidurals have been shown to be efficient after open surgery (6), and modern pain management strategies including intravenous lidocaine, wound infiltration or transverse abdominis plane (TAP) block emerge as alternatives for minimally invasive surgery (7).Most studies comparing open and laparoscopic surgery stated less pain after minimally invasive surgery (8,9), but only scarce data reporting on pain scores and actual analgesics consumption is available.The aims of the present study were to compare pain management strategies in patients undergoing open and minimally invasive colorectal surgical procedures, to analyse pain perception in both settings and to SummaryThe purpose of this prospective cohort study was to compare multimodal pain management and pain perception after open vs. laparoscopic colorectal surgery within enhanced recovery care.Pain scores at rest and at mobilization were prospectively assessed in consecutive patients using Visual Analog Scales (VAS 0-10) and consumption of different analgesics was recorded daily until 96 hours postoperatively.Uni-and multivariate risk factors for pain peaks (≥ 4/10) were identified by logistic regression and compared between two propensity score matched groups (open vs. laparoscopic).156 open and 176 laparoscopic procedures were included.Mean VAS scores were consistently < 3 until 96 hours at rest and at mobilization.Patients operated by laparoscopy experienced more pain peaks (≥ 4) within 24 hours (p < 0.05), while patients operated by open approach experienced more pain peaks (≥ 4) during mobilization at 72 hours (p < 0.05).Independent risk factors for insufficient pain control (≥ 4) within 24 hours from surgery were duration of the procedure (OR 3.37, 95%CI 2.03-5.59),emergency surgery (OR 3.01, 95%CI 1.72-5.31),wound infiltration (OR 3.23, 95%CI 0.97-10.70),age < 70 years (OR 2.03, 95% CI 1.18-3.48)and ASA I-II score (OR 2.06, 95% CI 1.19-3.56).The perioperative adding of lidocaine ± ketamine to opioids did not improve postoperative pain perception nor decrease morphine equivalents.In conclusion, overall pain scores were low after colorectal surgery.However, pain peaks remained a concern early after minimally invasive surgery and after epidural removal for open surgery.Multimodal strategies were not superior to opioids alone.