The Correlation Between CVP and SVV and Intraoperative Minimal Blood Loss in Living Donor Hepatectomy.

BACKGROUND: Blood loss during liver surgery is found to be correlated with central venous pressure (CVP). The aim of the current retrospective study is to find out the cutoff value of CVP and stroke volume variation (SVV), which may increase the risk of having intraoperative blood loss of more than 100 mL during living liver donor hepatectomies. METHOD AND PATIENTS: Twenty-seven adult living liver donors were divided into 2 groups according to whether they had intraoperative blood loss of less (G1) or more than 100 mL (G2). The mean values of the patients' CVP and SVV at the beginning of the transaction of the liver parenchyma was used as the cutoff point. Its correlation to intraoperative blood loss was evaluated using the χ2 test; P < .001 was regarded as significant. RESULTS: The cutoff points of CVP and SVV were 8 mm Hg and 13% respectively. The odds ratio of having blood loss exceeding 100 mL was 91.25 (P < .001) and 0.36 (P < .001) for CVP and SVV, respectively. CONCLUSION: CVP less than 5 mm Hg, as suggested by most authors, is not always clinical achievable. Our results show that a value of less than 8 mm Hg or SVV 13% is able to achieve a minimal blood loss of 100 mL during parenchyma transaction during a living donor hepatectomy. Measurements used to lower the CVP or increased SVV in our serial were intravenous fluids restriction and the use of a diuretic.

Degradation of peptide drugs by immobilized digestive proteases.

An in vitro assay using immobilized digestive enzymes and LC/MS has been developed to measure the susceptibility of orally administered peptide drugs to hydrolysis by the digestive system. Six different bioactive peptides and peptide drugs were digested using an established in vitro system incorporating four sets of immobilized digestive enzymes, which simulated gastric digestion in the stomach, digestion by pancreatic enzymes in the intestinal lumen, and digestion by mucosal peptidases at the intestinal brush border. Hydrolysis products were rapidly identified using LC/MS and coincided with those expected based on the substrate specificities of the immobilized enzymes. The LC/MS system consisted of a reversed phase HPLC connected to a mass spectrometer through a continuous-flow fast atom bombardment ionization system. Data acquired on the susceptibility of peptide drugs to hydrolysis by digestive enzymes could be used during the formulation of orally administered drugs to protect them from degradation prior to absorption in the gut. Also, this assay could be used to quickly identify those compounds in a structurally related series of new drugs that are most resistant to digestive proteases.