Increased visceral tissue perfusion with heated, humidified carbon dioxide insufflation during open abdominal surgery in a rodent model

Abstract

Tissue perfusion during surgery is important in reducing surgical site infections and promoting healing. This study aimed to determine if insufflation of the open abdomen with heated, humidified (HH) carbon dioxide (CO2) increased visceral tissue perfusion and core body temperature during open abdominal surgery in a rodent model. Using two different rodent models of open abdominal surgery, visceral perfusion and core temperature were measured. Visceral perfusion was investigated using a repeated measures crossover experiment with rodents receiving the same sequence of two alternating treatments: exposure to ambient air (no insufflation) and insufflation with HH CO2. Core body temperature was measured using an independent experimental design with three treatment groups: ambient air, HH CO2 and cold, dry (CD) CO2. Visceral perfusion was measured by laser speckle contrast analysis (LASCA) and core body temperature was measured with a rectal thermometer. Insufflation with HH CO2 into a rodent open abdominal cavity significantly increased visceral tissue perfusion (2.4 perfusion units (PU)/min (95% CI 1.23–3.58); p<0.0001) compared with ambient air, which significantly reduced visceral blood flow (-5.20 PU/min (95% CI -6.83- -3.58); p<0.0001). Insufflation of HH CO2 into the open abdominal cavity significantly increased core body temperature (+1.15 ± 0.14°C) compared with open cavities exposed to ambient air (-0.65 ± 0.52°C; p = 0.037), or cavities insufflated with CD CO2 (-0.73 ± 0.33°C; p = 0.006). Abdominal visceral temperatures also increased with HH CO2 insufflation compared with ambient air or CD CO2, as shown by infrared thermography. This study reports for the first time the use of LASCA to measure visceral perfusion in open abdominal surgery and shows that insufflation of open abdominal cavities with HH CO2 significantly increases visceral tissue perfusion and core body temperature.

Does intra‐operative humidification with warmed CO2 reduce surgical site infection in open colorectal surgery? A randomized control trial

“…Increased wound and core temperature may lower the risk of SSI by improving tissue oxygenation and immune cell function; 13 surgical humidification has been shown to have a significant increase in oxygen tension within the surgical tissues in a rodent model study 7 . Another rodent model study demonstrated that warm, humidified CO 2 is associated with increased tissue perfusion 8 . The effects of humidified CO 2 on pathogen culture should also be considered; S. aureus , for example, is a common pathogen associated with SSI, upon which CO 2 has a bacteriostatic effect at body temperature, which exponentially increases with time 4 …”

“…7 Another rodent model study demonstrated that warm, humidified CO 2 is associated with increased tissue perfusion. 8 The effects of humidified CO 2 on pathogen culture should also be considered; S. aureus, for example, is a common pathogen associated with SSI, upon which CO 2 has a bacteriostatic effect at body temperature, which exponentially increases with time. 4 SSI persist as common postoperative complications leading to increased morbidity and mortality, with a current SSI rate of 15% for open colorectal surgery at our institution.…”

“…(1) Pregnancy (2) Age > 80 years or <18 years (3) Severe end organ dysfunction, including end stage renal failure (eGFR <15 mL/minute or on haemodialysis), decompensated cardiac failure (NYHA class IV) or severe liver cirrhosis (Child Pugh B or greater). ( 4) Patients that have to return to theatre for pathology unrelated to surgical wound site infection such as anastomotic leaks, revisions or re-look laparotomy washouts (5) Evidence of sepsis, severe sepsis or septic shock based on clinical judgement (6) Contraindication for CO 2 (7) Morbid obesity, defined as BMI > 40 (8) Current abdominal wall infection/surgical site infection secondary to previous laparotomy/laparoscopy or from any other cause (9) History of laparotomy within the last 60 days (10) Immunological disease (e.g., HIV/AIDS) (11) Systemic steroid use or other immunosuppressant medication (12) ASA score > 4 (13) Poorly controlled diabetes mellitus, defined by presence of complications including retinopathy, neuropathy or nephropathy (14) Use of wound protection devices such as the Alexis port…”

“…Rodent studies have investigated the effect of warm, humidified CO 2 in open surgery and found it reduced peritoneal damage, increased tissue oxygenation and perfusion 7,8 . Increased mean core and wound temperature have also been demonstrated during open surgery in human trials 5 .…”

The role of warmed‐humidified carbon dioxide insufflation in colorectal surgery: A systematic review and meta‐analysis

“…Several small studies have examined the effects of WH-CO 2 in open and laparoscopic surgery with conflicting results [11,19,20].…”