While CO2 absorption reaches a plateau aer correct intraperitoneal insuation for 20–30min, extraperitoneal insuation of CO2 will lead to a rate of CO2 absorption of 50% or more. If signi­cant hypercapnia exceeding the “normal” increase of CO2 levels of up to 40% develops despite ade­quate modication of ventilation, or if 30 min aer establishing PP no plateau has been reached, accidental extraperitoneal insuation and/or production of cutaneous emphysema, a specic complication of laparoscopic procedures, should be considered [19, 30, 42].

establishing the PP. CO2 bubbles entering from established PP into accidentally opened veins may also occur, particularly in hypovolemic patients and in an unfavorable (i.e., head-up) position. Depending on the extent of gas embolism, a decrease in oxygen saturation may evolve along­side the abovementioned decrease in endtidal CO2. Although ventilatory parameters have not been changed, hypotension and cardiac arrhyth­mias may also occur. Precordial auscultation conrms the classic “mill-wheel” murmur. A gas embolism requires the immediate termination of CO2 insuation and deation of PP.Further mea­sures correspond to the classical procedure for acute treatment of air embolism, including place­ment of a CVC with the attempt of aspirating gas from the right ventricle and– in extreme cases– the use of cardiopulmonary bypass. Since, com­pared with other gases, ve times as much CO2 is needed to cause a hemodynamically relevant gas embolism and since CO2 is rapidly absorbed, CO2 embolism with such serious eects is extremely rare. Furthermore, the Trendelenburg position required for LIHR makes cranial vascular inva­sion of CO2 bubbles during analready established PP very unlikely. Case reports relate primarily to laparoscopic cholecystectomies with head-up positioning [1, 32, 36]. Accordingly, in laparo­scopic incisional and abdominal hernia surgery and especially in laparoscopic surgery of hiatal hernia, this complication seems more probable.

In laparoscopic surgery, CO2 to establish PP is applied with a temperature of 20 °C. Lengthy procedures and large quantities of CO2 can lead to marked and clinically relevant hypothermia [14]. Besides perioperative warming measures (heating blanket/heating pad), monitoring of body temperature is recommended to be able to counteract any further drop in temperature by appropriate measures. us inadequate oxygen consumption due to shivering and increased consumption of analgesics in the postoperative period can be avoided.