Influence of gas type, pressure, and temperature in laparoscopy-a systematic review

Abstract

Background: Laparoscopy is the favoured access to a lot of abdominal operations. The first step to laparoscopy is to establish a pneumoperitoneum which elevates the abdominal wall and provides for the surgeon's field of view. Different types of gas, temperatures, and pressures can be applied. This review aims to explain the rationale behind these topics, summarise the current knowledge, and demonstrate open questions. Methods: For each topic gas type, temperature, and pressure, separate systematic literature research on MEDLINE was performed. Randomized controlled trials (RCT) on adults, published between 2011 and March 2021 were considered. Cochrane Reviews summarizing older data were respected. Data extraction and analysis followed the PICO process. Results: Gas type-10 RCTs compared nitrous oxide (N2O, laughing gas), helium (He), or room air to carbon dioxide (CO2). Helium and N2O did not exhibit more cardiopulmonary complications than CO2. N2O has an anaesthetic effect. CO2 causes hypercapnia. Temperature-23 RCTs were found. Warm humidified CO2 was not advantageous over cold dry gas. Pressure-47 RCTs were included. Low intraabdominal pressure reduces postoperative shoulder pain but decreases the surgeon's comfort. Conclusions on the safety of low pressure for cardiopulmonary diseased patients cannot be inferred. Discussion: CO2 is the preferred gas to establish a pneumoperitoneum. Alternatives are not sufficiently evaluated. Room air is ubiquitously available and cheap and is therefore of interest to low-income countries. Warm humidified gas is not advantageous over cold dry CO2 but associated with higher costs. There is no benefit from using low instead of standard pressure. The safety of low-pressure pneumoperitoneum needs to be evaluated for multimorbid patients