Table 1.
Effects of humidified, warmed carbon dioxide on peritoneal inflammation
| Study | Study type | Humans/animals | Operation/samples taken | Device used | Study group |
Control group |
Results | ||
|---|---|---|---|---|---|---|---|---|---|
| Treatment | No. | Treatment | No. | ||||||
| Peng et al. 2009 [13] | RCT | Animals (rats) | Pneumoperitoneum creation (peritoneum/muscle of anterior/upper abdomen harvested) | Self-developed system | Warmed (37°C) + humidified (95% RH) CO2 gas | 75 | Cold (21°C) + dry (<1% RH) CO2 gas | 75 | Cold, dry group: intense peritoneal injury + intraabdominal adhesions |
| Warmed, humidified group: less peritoneal injury, no adhesion | |||||||||
| Brokelman et al. 2008 [10] | RCT | Humans | Laparoscopic cholecystectomy (parietal peritoneal biopsy) | Thermoflator (Karl Storz GmbH & Co., Tuttlingen, Germany) | Warmed (37°C) CO2 gas | 15 | Cold (21°C) CO2 | 15 | Significantly higher PAI (10x) level in the peritoneum of the control group with cold CO2 insufflation |
| Sammour et al. 2010 [11] | RCT | Humans | Elective laparoscopic colectomy (4-mL peritoneal drain fluid) | Insuflow (MR 860, Fisher & Paykel Healthcare, Auckland, New Zealand) | Warmed (37°C) + humidified (98% RH) CO2 | 41 | Standard CO2 (19°C, 0% RH) | 41 | No difference in peritoneal cytokine levels (IL1, 6, 8, 10, TNF-α) |
| Sammour et al. 2011 [14] | Prospective, non-RCT | Animals (rats) | Pneumoperitoneum creation (biopsies of liver, kidney, pancreas, jejunum) | Insufflator: CO2-OP-Pneu insufflator, (Wisap, Munich, Germany) | Warmed (37°C), humidified (98% RH) CO2 | 10 | Standard (19°C, 0% RH) | 10 | No difference in oxidative stress measures (malondialdehyde-MDA, Protein Carbonl-PC) |
| Humidifier: Insuflow (MR 860, Fisher & Paykel Healthcare) | |||||||||
| Moehrlen et al. 2006 [18] | RCT | Animals (NMRI mice) | Pneumoperitoneum creation (peritoneal lavage sample) | Olympus laparoscopic UHI-1 insufflator (Olympus Volketswil, Volketswil, Switzerland) | CO2 | 9 | Air | 9 | CO2 pneumoperitoneum resulted in less peritoneal inflammation Air resulted in higher PMN recruitment (3×), and lower PMN apoptosis rates |
| Hazebroek et al. 2002 [15] | RCT | Animals (rats) | Pneumoperitoneum creation (peritoneal tissue samples from anterior abdominal wall) | MR600 anesthesia respiratory humidifier (Fisher & Paykel Healthcare) | Group 1- Cold (24.9°C), dry (4% RH) CO2 | 12 | No pneumoperitoneum | 12 | No significant morphological difference among the groups |
| Group 2- Cold (24.8°C), humidified (87% RH) CO2 | 12 | ||||||||
| Group 3- Warm (36.9°C), dry (5% RH) CO2 | 12 | ||||||||
| Group 4- Warm (37.1°C), humidified (88% RH) CO2 | 12 | ||||||||
| Erikoglu et al. 2005 [17] | RCT | Animals (rats) | Pneumoperitoneum creation (peritoneal tissue samples) | Datascope GmbH, Passport XG, Bensheim | Warmed (40°C), humidified (98% RH) CO2 | 10 | No pneumoperitoneum | 10 | Greater peritoneal alteration in the cold, dry CO2 group |
| Cold (21°C), dry (2% RH) CO2 | 10 | ||||||||
| Margulis et al. 2005 [16] | RCT | Animals (pigs) | Laparoscopic nephrectomy (peritoneal fluid sample) | Insuflow (MR 860, Fisher & Paykel Healthcare) | Warmed, humidified CO2 | 5 | Cold, dry CO2 | 5 | No difference in serum and peritoneal levels of TNF-α, IL-1, IL-6, glucose, and cortisol |
RCT, randomized controlled trial; RH, relative humidity; TNF, tumor necrosis factor; IL, interleukin.