Comparison of continuous preperitoneal infiltration versus patient controlled analgesia for pain control in elective colorectal surgery

BACKGROUND: Post-operative analgesia is crucial in enhanced recovery after surgery and to minimize post-operative complications. There remains data paucity on the efficacy of preperitoneal analgesia (PPA) compared to patient-controlled analgesia (PCA). This study aims to examine the efficacy of preperitoneal infusion as analgesia following elective colorectal surgery. METHODS: This is a prospective cross-sectional study of all patients which underwent elective colorectal surgeries, performed in a tertiary surgical referral center with dedicated colorectal unit. Patients from May 2017 to April 2021 who underwent elective colorectal surgery were included in this study. Pain scores were reviewed and analyzed at regular intervals post-operatively for comparison. RESULTS: Amongst the 200 patients included, there were 174 patients in the PPA arm and 26 patients using PCA. Patients in the PPA group were older age (63.29 vs 56.00, P = 0.003). A total of 118 patients in PPA cohort (67.8%) and 21 from PCA cohort (80.8%) underwent open surgery and the remaining 82 patients underwent laparoscopic surgeries. Although postoperative pain scores were consistently below 5 and reduced in trend from 2 hours to 96 hours postoperatively in both groups, the pain scores on coughing markedly reduced in the PPA group when compared PCA alone. The total dosage of opioid required in PPA cohort was also significantly lower when compared to PCA group at the first 24 hours postoperatively 12.21 (±13.0) vs 20.0 (±14.43), P = 0.048. CONCLUSIONS: PPA is a comparable modality for analgesia after elective colorectal surgery that reduces the opioid requirement postoperatively giving adequate pain relief. PPA should be considered as an alternative modality for multi-modal analgesia.