Examining the impact of intra-abdominal pressure on post-op recovery and innate cytokine production following laparoscopic colorectal surgery as part of the enhanced recovery after surgery initiative was the purpose of this study. Low-pressure pneumoperitoneum, made possible by profound neuromuscular blockade (NMB), is increasingly supported by data for its safety and benefits. However, the connection between surgical damage, postoperative immunological dysfunction, and infectious complications is poorly understood. Treatment of 178 patients with pneumoperitoneum at either standard pressure (12 mm Hg) with moderate NMB (train-of-4 1-2) or low pressure (8 mm Hg) aided by deep NMB was randomized and controlled (posttetanic count 1–2).
Quality of recovery on postoperative day 1 (as measured by the Quality of Recovery 40 questionnaire) was the primary outcome (POD1). In the immunological substudy (n=100), the primary result was the ability to produce tumor necrosis factor ex vivo in response to endotoxin stimulation on POD1. Patients operated on at low pressure had a significantly higher Quality of Recovery 40 score on POD1 (167 vs. 159; MD: 8.3 points; 95% CI: 2.5, 14.1; P=0.005), and their cytokine production capacity declined significantly less for tumor necrosis factor α, and interleukin-6 (MD: -172 pg/mL; 95% CI: -316, -27; P=0.021 and MD: −1282 pg/mL; 95% CI: −2505, −59; P=0.040, respectively) for patients operated at low pressure.
The ability to produce ex vivo cytokines was less hampered in the early postoperative period when low pressure was present, and there was less hypoxia and inflammation at the surgical site. Patients experienced less acute discomfort and fewer infectious problems after 30 days of low blood pressure. The use of low intra-abdominal pressure during laparoscopic colorectal surgery is safe, enhances the postoperative quality of recovery, and protects the homeostasis of the innate immune system, making it a desirable addition to future enhanced recovery after surgery programs.