Independent testing of the Fisher & Paykel Healthcare MR860 Laparoscopic Humidification System

Abstract

In laparoscopic surgery CO2 is commonly insufflated at room temperature, with a relative humidity approaching 0%. There has been an increase in utilization of devices to warm and humidify the insufflated gas to avoid potential detrimental effects caused by desiccation. Available data on the performance of these devices are limited. We aimed to conduct independent testing of the Fisher & Paykel MR860 Laparoscopic Humidification System at variable flow rates. A 2.5l insulated chamber was constructed and a digital thermo-hygrometer placed inside it. The humidifier water vessel was weighed and exactly 30.0g of water poured in. 50.0L of CO2 was insufflated into the chamber via the humidifier at 2.0L/min, 4.0l/min, 6.0l/min, 8.0l/min, and 10l/min using a laparoscopic insufflator. Measurements of temperature and humidity in the chamber were taken at 30 second intervals. After 50.0l of gas was insufflated the water left in the humidifier was weighed, and this was used to calculate the mean absolute humidity of the insufflated gas by the gravimetric method. At every flow rate, > 98.0% relative humidity was achieved in the chamber after less than 30 seconds of insufflation. Using the gravimetric estimate, the humidifier was able to saturate 50.0l of CO2 to close to saturation humidity at every flow rate tested. The Fisher & Paykel MR860 Laparoscopic Humidification System effectively humidifies insufflated CO2 at a range of flow rates commonly used in the surgical setting.

Physiological effects of partial amniotic carbon dioxide insufflation with cold, dry vs heated, humidified gas in a sheep model

“…Heating CO 2 gas from 22 °C to 40 °C reduces its solubility by nearly 40%. Additionally, humidification would have reduced the intra‐amniotic partial pressure of CO 2 (from 775 to ≈720 mmHg), due to the contribution of water vapor pressure. Collectively, these may have reduced the absorption of CO 2 in fetuses exposed to heated, humidified gas.…”

“…vapor pressure [17][18][19] . Collectively, these may have reduced the absorption of CO 2 in fetuses exposed to heated, humidified gas.…”

Postoperative hypothermia and surgical site infection following peritoneal insufflation with warm, humidified carbon dioxide during laparoscopic colorectal surgery: a cohort study with cost-effectiveness analysis

“…The HumiGard™ CO 2 conditioning device was installed in July 2013 and placed on the stack system beside the insufflator. It delivered warmed and humidified CO 2 to the patient via a dual-lumen insulated tubing system, at a temperature of 37 degrees centigrade and humidity of greater than 98 % [9]. Flow rate and intra-abdominal pressure were controlled at the discretion of the operating surgeon.…”

The Effects of Insufflation Conditions on Rat Mesothelium

“…Under standard use, as per study group 4, the insufflation gas passes over a heated humidification chamber filled with 30 mL of sterile water which is designed to condition the gas to 37°C and 100% RH [12]. The condition of the gas is maintained as it flows down the humidified insufflation tube which acts to maintain the condition of the gas direct to the laparoscopic port.…”