P606 Introduction: Small bowel transplantation (SBTx) is the treatment of choice for short gut syndrome. SBTx can be divided into several operative phases: dissection phase, vascular anastomosis phase and after reperfusion of the small bowel, intestinal reconstruction phase [1]. Understanding the hemodynamic and metabolic changes occurring throughout the procedure is required for optimal patient outcome. Methods: Thirty adult patients, mean age of 44 ± 12 years, who underwent SBTx between May 2000 and July 2002 were studied. Etiologies were splanchnic vascular thrombosis (13 patients), Crohn’s disease (6 patients), volvulus (4 patients) and others (7 patients). Intraoperative hemodynamic monitoring included mean arterial pressure (MAP), mean pulmonary artery pressure (mPAP), pulmonary wedge capillary pressure (PWCP), central venous pressure (CVP) and cardiac output (CO), together with metabolic parameters: pH, base excess (BE); serum sodium (Na+); serum potassium (K+); ionized calcium (Ca++) and lactate. T-paired test was used. p < 0.05 was considered statistically significant. All data are presented as mean values ± SD. Results: There was a significant decrease in MAP 30 seconds after reperfusion (61 ± 15 mm Hg), compared to baseline values (79 ± 12 mm Hg). There was no significant change in HR. Hypotension with MAP less than 60 mm Hg within 5 minutes after reperfusion, defined as “postreperfusion syndrome” (PRS) [2], was found in 47 % of the patients. PRS was treated with small doses of epinephrine (19.2 ± 8.6 μg) and fluid bolus if required. In 40 % of the patients an infusion of epinephrine or dopamine was started during the first hour postreperfusion. None of the patients were on inotropes at the end of surgery. Hemodynamic, electrolytic and acid base parameters were within normal limits during all the operative phases. Cardiac output increased significantly immediately after reperfusion (10.6 ± 2.4 l/min) compared with the baseline (8.1 ± 2.5 l/min). There was a significant decrease in SVR during the vascular anastomosis phase (600 ± 160 dyn · sec/cm5), which persisted 5 minutes after reperfusion (464 ± 135 dyn · sec/cm5) and till end of surgery (434 ± 140 dyn · sec/cm5) compared to baseline (751 ± 299 dyn · sec/cm5). Significant increases in filling pressures: CVP, PWCP and mPAP were noted during the vascular anastomosis phase and 5 minutes after reperfusion (13, 17 and 22 mm Hg respectively) when compared to baseline values (10, 14 and 18 mm Hg respectively). Five minutes after reperfusion K+ was significantly increased (4 ± 0.6 mmol/l) compared with baseline (3.4 ± 0.4 mmol/l). A continuous significant increase in lactate was noted throughout the surgery. Conclusions: The incidence of PRS was higher in SBTx patients (47 %) compared with the 30 % reported incidence for liver transplantation [3]. Significant increases in filling pressures (CVP, PCWP, mPAP), CO, and K+, combined with significantly decreasing SVR at stage III+5 were part of the PRS. Understanding these changes is required for optimal patient management.