Humidify to Protect During Surgery

Effects of Cold Dry CO2

Effects of cold, dry CO2 on the peritoneum

As the cold dry gas passes over the peritoneal tissue it draws heat and moisture from the body. This desiccation results in the shortening and progressive disappearance of microvilli on the mesothelial cells. Under this stress, the mesothelial cells start to bulge and retract, breaking cell junctions. Finally a large number of cells undergo apoptosis and detach from the basement membrane, leaving it exposed.6,7

Effects of Warm CO2

Effects of warm, humidified CO2 on the peritoneum

The use of warm, humidified CO2 during surgery can maintain the integrity and function of the peritoneum. This helps protect the patient from pain1 and hypothermia1, reduces the risks of SSIs5, adhesions11 and cancer metastasis.10,11

Benefits of Surgical Humidification

Surgical Humidification reduces cellular desiccation and evaporative cooling by delivering warm, humidified CO2 during laparoscopic and open surgery.1-4 This has been shown to significantly reduce the risk of postoperative complications and their associated costs.5-9

The condition of the CO2 traditionally used during laparoscopic surgery and the ambient air during open surgery is vastly different to the conditions of the human body, directly drawing heat and moisture from the already compromised patient.

Desiccation of the peritoneum occurs swiftly after exposure resulting in cellular damage and exposure of the basement membrane.

Desiccation and associated cooling can manifest in significant post-operative complications including surgical site infections (SSI),5 cancer metastases10,11 and adhesions.11

Improved Patient Care and Outcomes with Surgical Humidification

Surgical Humidification has been shown to significantly reduce the risk of postoperative complications and their associated costs.5-9 

Inadvertent perioperative hypothermia is a common complication of surgical procedures. It is associated with a multitude of poor outcomes for the patient but is preventable.

Images courtesy of Matsuda et al., 200212

Thermal images above demonstrate the cooling effects of 2 hours cold, dry CO2 laparoscopic insufflation compared with warm humidified insufflation in a porcine model.12

In open surgery, “warm humidified CO2 significantly increases both wound and core temperature during open abdominal procedures and helps to maintain normothermia.” Frey et al., 20123

Graph reproduced from Frey et al., 20123

A reduction in SSI rate from 12.1% to 4.7% with the use of warm, humidified CO2 during laparoscopic colorectal surgery is indicated in present clinical evidence.9

Subcutaneous changes in oxygen tension predict the incidence of Surgical Site Infections. The better oxygenated the wound, the less chance of getting an infection.13

Research in rodent models shows that the average increase in pO2 (tissue partial pressure of oxygen) with warm, humidified CO2 is 29.8 mmHg14
An increase in pO2 from base line greater than 25 mmHg is clinically significant
An increase of 25 mmHg in pO2 is shown to predict a 30% drop in SSI rate13
A 40-50% fall in pO2 is highly predictive of anastomotic leakage15

There is an immediate decrease in pO2 when warm, humidified CO2 is stopped. The graph on the right shows the change in tissue oxygenation when exposed to ambient air or humidified CO2 in a rodent model. The shaded area demonstrates when warm, humidified insufflation was in use.

Graph reproduced from Marshall et al., 201514

Local insufflation of warm, humidified CO2 during laparoscopic and open surgery has been shown to reduce treatment costs per patient.

Mathematical models independently developed by York Health Economics Consortium, show that the average spend to treat post-operative complications from colorectal surgery decreases by more than £20,000 per 100 patients. This is due to substantively decreased incidence of post-operative complications in both laparoscopic and open surgery.18

“Using heated humidified CO2 during laparoscopy reduces postoperative pain, and postoperative hypothermia as compared with dry CO2. Cumulative analgesic usage is also lower, which may help in avoiding the adverse effects of narcotics and non-steroidal anti-inflammatory drugs.”

Sajid et al., 20081


Graph reproduced from Sajid et al.,20081

Desiccation of the Peritoneum and Cancer Cells

Reduction in Adhesions and Peritoneal Metastasis*

Watch this video to see how the peritoneum acts as a barrier to protect from adhesion formation and tumour implantation. When the protective layer of mesothelial cells is disrupted through exposure to cold, dry CO2, the basement membrane becomes exposed.16

“Tumour cells rapidly fill the spaces left by the mesothelial cells, suggesting that the tumour cells have a strong preferential affinity for the basement membrane. Tumour cells that do invade then proliferate into the connective tissue”

Volz et al., 199917

As shown in an animal model

Testimonial Videos

A group of clinicians recently gathered in Auckland, New Zealand to share their clinical and scientific insights for using humidification during surgery.

Dr Brett Pearce
Dr Brett Pearce
Dr Sandra Carpenteri
Dr Sandra Carpenteri
Pernilla Lindner
Pernilla Lindner
Professor Craig Lynch
Professor Craig Lynch
Professor Jan van der Linden
Professor Jan van der Linden