[Hemodynamic changes caused by laparotomy during aorto-iliac surgery].

A haemodynamic study was carried out on 53 patients undergoing elective surgery of the abdominal aorta in order to assess the haemodynamic changes consequent to abdominal manipulations prior to aortic clamping. Surgery was carried out under general anaesthesia and ventilation was controlled. The following parameters were monitored: mean arterial pressure (Pa), cardiac index (CI), systolic index (SI), systemic vascular resistances (Rsa), pulmonary vascular resistances (Rpa), heart rate (fC). Cutaneous circulation was monitored using a photoplethysmographic transducer. The following haemodynamic pattern was seen as the peritoneal cavity was opened and traction on the mesentery was applied: CI +40.7%; fC +28.61%; SI +9.85%; Rsa -39.16%; Rpa -28.43%; Pa -15.7%. The recording of the facial cutaneous photoplethysmographic wave showed an increase of 50%. In some extreme cases, a state of cardiovascular collapse with marked cutaneous erythema strongly resembling anaphylactic shock ensued. The physiopathology of these cardiovascular reactions is unclear, but the haemodynamic pattern as well as the cutaneous vasodilation suggest a stimulation of both vagal and sympathetic nervous systems and the release of vasoactive substances into the general circulation.