Hypercapnia and surgical site infection: a randomized trial

Area of Science:

• Surgical oncology
• Anesthesiology
• Critical care medicine

Background:

• Tissue oxygenation is a key factor in surgical site infection (SSI) risk.
• Mild intraoperative hypercapnia can improve tissue oxygenation and possess anti-inflammatory properties.
• The impact of hypercapnia on SSI risk following colon resection remains uninvestigated.

Purpose of the Study:

• To test the hypothesis that mild intraoperative hypercapnia reduces the risk of SSI in patients undergoing colon resection surgery.
• To evaluate the efficacy of intraoperative hypercapnia as a strategy for SSI prevention.

Main Methods:

• Randomized controlled trial comparing intraoperative normocapnia (PECO2 ≈ 35 mm Hg) versus hypercapnia (PECO2 ≈ 50 mm Hg) in elective colon resection patients.
• Blinded assessment of perioperative SSI using CDC criteria for 30 days post-surgery.
• Sample size: 623 in normocapnia group, 592 in hypercapnia group.

Main Results:

• No statistically significant difference in SSI rates between the normocapnia (13.3%) and hypercapnia (11.2%) groups (P=0.29).
• The trial was stopped early due to a smaller-than-projected effect size, precluding definitive conclusions of 'no difference'.
• Patients in the hypercapnia group experienced a shorter time to their first bowel movement (half-a-day faster).

Conclusions:

• Mild intraoperative hypercapnia demonstrated minimal to no ability to prevent SSI after colon resection.
• Alternative strategies for SSI risk reduction should be prioritized over intraoperative hypercapnia.
• Hypercapnia may offer other benefits, such as accelerated gastrointestinal recovery.