Table 4.
Effects of warmed, humidified carbon dioxide on respiratory function
| Study | Study type | Humans/animals | Operation | Device used | Study group |
Control group |
Results | ||
|---|---|---|---|---|---|---|---|---|---|
| Treatment | No. | Treatment | No. | ||||||
| Bashirov et al. 2007 [43] | Prospective, non-RCT | Animals (pigs) | Pneumoperitoneum creation | Model Ref L-70 NI Hotline (Sims-Smith Industries Medical Systems, Rockland, MA, USA) | Warmed CO2 groups | 6 (7°C), 6 (22°C), 6 (37°C) | No CO2 pneumoperitoneum | 6 | Increase in temperature of CO2 resulted in increased peritoneal CO2 absorption, increased PaCO2 and a greater decrease in pH (7.44 vs. 7.26) |
| Uzunkoy et al. 2006 [44] | RCT | Humans | Elective lap cholecystectomy | H-500 fluid warmer (Level 1 Technologies, Inc.,Rockland, MA, USA) | Warmed CO2 (37°C) | 15 | Cold CO2 (21°C) | 15 | Pulmonary function test performed 12 hours after the operation found lung function was significantly better in those receiving warmed CO2 (FVC, FEV1, PEF) |
| Bergström et al. 2008 [42] | Prospective, non-RCT | Animals (pigs) | Pneumoperitoneum creation | Laparoscopic insufflator (Storz, Tuttlingen, Germany) | CO2 | 10 | Helium | 10 | CO2 pneumoperitoneum resulted in significantly lower peritoneal pH (6.4 vs. 7.5, P = 0.001) |
| However, very minimal changes in arterial pH (7.43 vs. 7.49, P = 0.004) were found, with no clinical significance | |||||||||
| Ozgonul et al. 2007 [24] | RCT | Humans | Elective laparoscopic cholecystectomy | H-500 fluid warmer (Level 1 Technologies, Inc., MA, USA) | Warmed (37°C) CO2 | 31 | Cold (21°C) CO2 | 31 | No significant difference in arterial pH, pCO2, or HCO3- |
RCT, randomized controlled trial; RH, relative humidity; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 second; PEF, peak expiratory flow.