Physiological changes during pneumoperitoneum

Indications for a laparoscopic approach to surgically treatable diseases are expanding rapidly. With that expansion, physiological and pathological changes during CO₂ pneumoperitoneum become more and more apparent. In the cardiovascular system, CO₂ pneumoperitoneum decreases venous back flow from the lower extremities but increases cardiac preload and vascular resistance. In the respiratory system, CO₂ insufflation results in a hypercapnia which can easily be monitored and corrected in a ventilated patient. Splanchnic and especially mesenteric and renal blood flow are decreased by up to 30%. Therefore, pneumoperitoneum should be applied at a minimal pressure with evacuation of CO₂ at the end of surgery especially in patients with preexisting cardiovascular, pulmonary or renal diseases, in the elderly, and in obese patients.