Effects of intravenous pentafraction on lung and soft tissue liquid exchange in hypoproteinemic sheep

Abstract

Effects of infusing pentafraction (Pen), a synthetic hydroxyethyl starch plasma volume expander, on lung and soft tissue lymph flux were compared in nonanesthetized sheep that were protein depleted by batch plasmapheresis. Pen (5%) was infused to raise pulmonary arterial wedge pressure by 5 mmHg for 2 h (1.8 +/- 0.3 l). Pen raised plasma osmotic pressure from plasmapheresis baseline (10.7 +/- 2.2 mmHg; preplasmapheresis baseline, 19.6 +/- 0.6 mmHg) to 16.6 +/- 2.4 mmHg. After Pen, lung lymph flows peaked at 3.9 +/- 2.0 times a preplasmapheresis baseline value of 1.0 (plasmapheresis baseline, 2.7 +/- 0.7), but soft tissue lymph flows rose insignificantly. Plasma Pen concentrations were 2.3 +/- 1.0% postinfusion and 1.6 +/- 0.3% at 12 h. Pen mean molecular masses at these times, measured by high-performance liquid chromatography, were 160 +/- 44 and 129 +/- 23 kDa, respectively. In lung lymph, Pen concentrations were 0.8 +/- 0.6% postinfusion and 0.7 +/- 0.2% at 12 h, with mean molecular masses of 125 +/- 44 and 112 +/- 18 kDa, respectively. In soft tissue lymph Pen was nearly undetectable postinfusion, but at 12 h concentrations averaged 0.3 +/- 0.2% with a mean molecular mass of 80 +/- 10 kDa. The osmotic effectiveness of Pen may be related to its molecular mass, which was large enough to restrict filtration so that the plasma-to-lung lymph osmotic pressure gradient widened. Pen remained effective in the circulation for at least 24 h.

Lung lymph response to overinfusion with hydroxyethyl starch in sheep

“…The combination of restoration of circulating plasma volume with minimal contribution to increasing fluid accumulation, particularly in the lung, is important in colloid infusion ( 10–15, 18–20). We examined the differences in these factors among HES solutions in normal sheep.…”

“…(polysaccharides versus hydroxyethyl starch). However, Conhaim et al ( 10) and Kramer et al ( 26) measured the high molecular HES and dextran concentrations of lung lymph and non‐pulmonary soft tissue in sheep, respectively. In both studies, more rapid appearance and movement of colloid were observed in lung lymph than in non‐pulmonary soft tissue.…”

“…Several previous studies have addressed fluid exchange across pulmonary microvessels during and after high molecular HES infusion ( 10–15). The infusion of HES raises plasma macromolecular osmotic and hydrostatic pressures in microcirculation.…”

Preservation solutions for attenuation of ischemia–reperfusion injury in vascularized composite allotransplantation

“…The size of colloids used in preservation solutions is optimized to maximize surface area for H 2 O adsorption and minimize clearance and entry into the lymphatic system. 62 Early preservation solutions derived from whole blood used human serum albumin (HSA) as the primary oncotic agent; however, with the clinical success of UWS, pentafraction replaced HSA as the primary colloid of choice. 63 Pentafraction is a solution of biodegradable hydroxyethyl starch macromolecules with molecular weights between 10 and 100 kDa.…”

Fluid therapy with artificial colloids: complications and controversies

“…One study found that 85% of hydroxyethyl starch molecules were smaller than 300 kDa, 50% were smaller than 100 kDa, and that values for RMM ranged up to 5000 kDa (Zikria 1994). A hydroxyethyl starch solution with an average RMM of 100–300 kDa has particular advantages: it seems to optimize volume expansion and duration of action (Conhaim et al. 1993) causes fewer effects on coagulation (Treib et al.…”