Gastric intramucosal pHI: An indicator of dstraoperattve spanchnic perfusion during orthotopic liver transplant

Introduction: Tissue perfusion and oxygen utilization is compromised during compensated shock, i.e., preferential blood flow redistribution. This has been associated with increased morbidity and mortality and lead to the development of regional tissue metabolism monitoring to improve splanchnic perfusion. Methods: Gastric intramucosal pH values (pHi) of fifty liver transplant patients were obtained at four phases: baseline (B), portal vein clamping or initiation of vcno-venobypass (P), reperfusion (R) and postoperanvely (PO). These values were compared to more traditional methods of invasive haemodynamic monitoring (CO, SVO2, etc.), postoperative graft function and patient outcome. Results: Mean pHis were: B=7.41 (0.11), P=7.27 (0.14), R-7.31 (0.10), and PO7.46 (0.08). Paired-T tests demonstrated a significant difference between measured pHi values, except between P-pHi and R-pHi (p<0.03). Regression analysis was significant between R- and P-pHi (r=0.49), R- and B-pHi (r-0.35) and P- and B-pHi (r=0.5i). An abnormal pHi (< 7.30) divided patients in two groups per measurement. B-pHi < 7.30 was significantly associated with an increased lactic acidosis on postoperative day 3 (POD-3). Abnormal P-pHi was associated with increased postoperative (TrlM'T1"'iV. postoperative lactic acidosis and significant renal dysfunction on discharge (pO.OS). Low R-pHi was also statistically associated with an increased lactic acidosis, as well at elevated postoperative total bilirubin and decreased fibrinogen on POD-3 (pO.OS). Patients with a low R-pHi required more intra-operative fluids and transfusions of red cells, platelets and plasma, displaying a higher incidence of transient postoperative renal dysfunction and need of ventilatory support (p<0.05). All patients with at least any one abnormal pHi value had higher requirements for cryoprecipitate intraoperatively and a higher readmission rate in me first 6 months after surgery. PHi was not related to intraoperative haemodynamic instability. Conclusions: Use of intraoperative pHi monitoring may be useful to distinguish those patients with postoperative complications and predict graft dysfunction. Prevention and treatment of a low pHi may obviate these problems.