Effect of increased cardiac output on liver blood flow, oxygen exchange and metabolic rate during longterm endotoxin‐induced shock in pigs

Abstract

1 We investigated hepatic blood¯ow, O 2 exchange and metabolism in porcine endotoxic shock (Control, n=8; Endotoxin, n=10) with administration of hydroxyethylstarch to maintain arterial pressure (MAP)460 mmHg. 2 Before and 12, 18 and 24 h after starting continuous i.v. endotoxin we measured portal venous and hepatic arterial blood¯ow, intracapillary haemoglobin O 2 saturation (Hb-O 2 %) of the liver surface and arterial, portal and hepatic venous lactate, pyruvate, glyercol and alanine concentrations. Glucose production rate was derived from the plasma isotope enrichment during infusion of [6, H 2 ]-glucose. 3 Despite a sustained 50% increase in cardiac output endotoxin caused a progressive, signi®cant fall in MAP. Liver blood¯ow signi®cantly increased, but endotoxin aected neither hepatic O 2 delivery and uptake nor mean intracapillary Hb-O 2 % and Hb-O 2 % frequency distributions. 4 Endotoxin nearly doubled endogenous glucose production rate while hepatic lactate, alanine and glycerol uptake rates progressively decreased signi®cantly. The lactate uptake rate even became negative (P50.05 vs Control). Endotoxin caused portal and hepatic venous pH to fall signi®cantly concomitant with signi®cantly increased arterial, portal and hepatic venous lactate/pyruvate ratios. 5 During endotoxic shock increased cardiac output achieved by colloid infusion maintained elevated liver blood¯ow and thereby macro-and microcirculatory O 2 supply. Glucose production rate nearly doubled with complete dissociation of hepatic uptake of glucogenic precursors and glucose release. Despite well-preserved capillary oxygenation increased lactate/pyruvate ratios re¯ecting impaired cytosolic redox state suggested deranged liver energy balance, possibly due to the O 2 requirements of gluconeogenesis.

Hepatic O2 exchange and liver energy metabolism in hyperdynamic porcine endotoxemia: effects of iloprost

“…The animals were premedicated and anesthetized as described in detail previously. This approach had been shown to provide sufficient anesthesia both for the surgical procedures and the ongoing experiment [21,22].…”

“…The surgical procedure for the placement of a central venous catheter, a balloon-tipped thermodilution pulmonary artery catheter (93A754 7F, Baxter Healthcare, Irvine, Calif., USA), and an arterial line for continuous blood pressure recording and thermaldye double indicator dilution measurements (FT-Pulsiocath PV 2023, Pulsion, Munich, Germany) is described in detail elsewhere [21,22].…”

“…A midline laparotomy was performed, and precalibrated ultrasonic flow probes (Transonic Systems, Ithaca, N. Y., USA) were placed around the portal vein and the common hepatic artery as described previously [21,22]. A 4-Fr catheter (CS-16402, Arrow, Reading, Pa., USA) was then introduced into the portal vein, and an angiography catheter (7F Multipurpose A-1, Cordis, Roden, The Netherlands) was introduced via the right jugular vein into a hepatic vein under ultrasound guidance.…”

“…Capillary hemoglobin O 2 saturation (HbScO 2 ) on the liver surface was measured by means of remission spectrophotometry using the Erlanger Mikrolightguide spectrophotometer device (EM-PHO; Bodenseewerk Gerätetechnik, Überlingen, Germany) as described previously [21,23].…”

Ropivacaine May Have Advantages Compared to Bupivacaine in Porcine Endotoxemic Shock

“…The 29 piglets were allocated by randomization in blocks, to one of the following protocols: 24 animals received intravenous endotoxin (E. Coli 0111: B4; Sigma Chemicals, St Louis, MO, USA) at 4 µg x kg -1 x h -1 until duplication of the MPAP, considered as the onset of a severe experimental endotoxin-induced sepsis (17,18), and thereafter at 1 µg x kg -1 x h -1 throughout the 6 h experimental period. The time between the start of the endotoxin-infusion and the doubling of MPAP was 30 -35 min.…”