Hepatic venous catheterization in patients undergoing positive end-expiratory pressure ventilation after OLT: technique and clinical impact.

The objective of this study was to determine the feasibility and clinical impact of hepatic venous oxygenation monitoring in patients undergoing positive end-expiratory pressure (PEEP) ventilation after OLT. The design comprised a prospective study using repeated-measures design, within an intensive-care unit for liver-transplanted patients in a university hospital. Sixteen consecutive adult patients undergoing orthotopic liver transplantation were enrolled. Postoperatively, a fiber-optic pulmonary artery catheter was inserted into the right hepatic vein. Patients were submitted to controlled ventilation with three different levels of end-expiratory pressure (PEEP): 0, 5 and 10 mbar. Hemodynamics, hepatic venous pressure, mixed venous (SvO2) and hepatic venous oxygenation (SvhO2) were measured. The average time required for hepatic venous catheterization was 2.9 +/- 1.2 min; serious complications were not observed. PEEP 5 mbar did not alter hemodynamics and SvhO2; PEEP 10 mbar significantly reduced cardiac index, SvO2 and widened arteriovenous content difference (p < 0.05). The mean difference between SvO2 and SvhO2 was 6.3 +/- 6.0% and did not change during PEEP ventilation. A significantly positive relationship was observed between SvO2 and SvhO2 (r = 0.91, p < 0.05). Hepatic venous catheterization appeared to be practical and could be utilized to evaluate the effects of therapeutic interventions on the transplanted liver. However, the small number of patients studied will not allow the assessment of any risk-benefit ratio of the technique investigated. Low levels of PEEP provided hemodynamic stability and did not alter hepatic oxygen supply-demand ratio.(ABSTRACT TRUNCATED AT 250 WORDS)