[Mesenteric traction syndrome during the operation of aneurysms of the abdominal aorta--histamine release and prophylaxis with antihistaminics].

Mesenteric traction syndrome occurs during abdominal surgery and is described as sudden tachycardia, hypotension and flush. Among other etiological factors, eventeration or mesenteric traction of the small intestine may cause histamine release from mesenteric mast cells. Therefore, our hypothesis was that mesenteric traction syndrome could be positively influenced by prophylactic administration of H1- and and H2-antihistamines. Seventeen male patients (ASA groups III-V, 48-78 years old) were investigated in a randomised double blind study during elective abdominal aortic aneurysm (AAA) repair; which, in our opinion, is one of the most standardised surgical procedures. Eight patients had pre-anaesthetic prophylaxis with 0.1 mg/kg BW dimetindene (H1-receptor antagonist) plus 5 mg/kg BW cimetidine (H2-receptor antagonist) diluted with 100 ml 0.9% NaCl, while 9 patients received a placebo (100 ml 0.9% NaCl). Anaesthesia and invasive haemodynamic monitoring were standardised in all patients. Haemodynamic parameters, plasma histamine concentrations and clinical symptoms were determined one min after skin incision (HS), and 5 and 20 min after mesenteric traction (5' EV and 20' EV). Statistical analyses were performed using the Student's t-test, the Mann-Whitney-U-test for continuous data and Chi2-test for incidences. The incidence of histamine release was 55.5% (5/9) in the placebo group vs. 37.5% (3/8) in the antihistamine group (p > 0.05, Chi2-test). Plasma histamine levels (mean +/- SD) were higher in the placebo group than in the antihistamine group at 5 and 20 min after mesenteric traction, but there was no statistical significance. Arrhythmias were significantly more frequent in the placebo group (6 times) than in the antihistamine group (none) (p = 0.005 Chi2-test). Systolic blood pressure was not statistically different between the groups (e.g. 5 min after mesenteric traction, mean +/- SD; placebo 111 +/- 20 mm Hg vs. antihistamines 119 +/- 35 mm Hg). In the placebo group, however, the haemodynamics only stabilised 5 min after mesenteric traction when anaesthetic gas concentration was repeatedly reduced and vasopressor/volume administration was increased (placebo group = 20 times vs. antihistamine group = 8 times (p = 0.001, Chi2-test). From these results we conclude that prophylactic administration of antihistamines reduces in particular the incidence of arrhythmias and the number of stabilising measures during mesenteric traction. Prophylaxis with H1- and H2-antihistamines may therefore be of perioperative benefit and should be considered in AAA surgery.