Impact of complicated intra-abdominal infection on albumin synthesis rate

Abstract

To study the impact of complicated intra-abdominal infections on albumin synthesis rate. Eight patients with complicated intra-abdominal infections associated with intestinal fistula were admitted to the Research Institute of General Surgery at the Jinling Hospital between December 2009 and October 2010. Eight healthy volunteers matched for age, sex, and body mass index were enrolled as controls. All the subjects were given a primed, constant infusion of sterile L-[ring-(2)H(5)]-phenylalanine solution (priming dose: 4 μmol/kg, infusion rate: 6 μmol·kg(-1)·min(-1)) via peripheral venous lines in fast state. Arterial blood samples(3 ml) were drawn before and throughout the infusion at hourly intervals. The enrichment of L-[ring-(2)H(5)]-phenylalanine from the plasma free amino acid pool and from albumin were determined by gas chromatography/mass spectrometry analysis. Both plasma total protein concentration(62.2±1.0) g/L and plasma albumin concentration (32.5±4.0) g/L in patients with complicated intra-abdominal infection were lower compared with controls[(74.2±1.7) g/L and (46.1±2.6) g/L, both P<0.05]. Body temperature, neutrophil count and plasma C-reactive protein concentration in patients with infection were significantly greater than the levels in control subjects(P<0.05). Albumin synthesis rate in patients with intra-abdominal infection was significantly lower than that in the control group [(5.3±1.6)%/d and (7.8±1.2)%/d respectively, P<0.05]. The measurement of plasma free amino acid concentration showed that plasma glutamic acid level was greater than that in control subjects, and that plasma phenylalanine and proline levels were lower than those in controls. Complicated intra-abdominal infection inhibits albumin synthesis rate in patients with intestinal fistula, which may partially contribute to the decrease of plasma albumin concentration.