HIGH-DOSE OF HYDROXYETHYL STARCH AND HUMAN ALBUMIN HAVE SIMILAR EFFECTS ON MONOCYTE FUNCTION AND ONCOTIC PRESSURE

The accumulation of hydroxyethyl starches (HES) in monocytes/macrophag es has raised concern over their potential detrimental effects on host defences. We assessed prospectively the function of circulating monoc ytes isolated from patients treated with plasma exchange (PE) using HE S. The study was carried out in the medical intensive care unit of a u niversity hospital. Eight patients underwent PE for neurological disor ders. Each patient underwent three PEs, 48 h apart. The total exchange volume was 4L per PE. Only 4% human albumin was used for the first PE . In the second and third PEs, the plasma substitute was 2 L of HES (2 00000/6%/0.62) and 2L of albumin. Mononuclear cells were collected bef ore and immediately after each PE and 48 h after the last PE. They wer e placed in suspension culture and incubated with lipopolysaccharide ( LPS). Monocyte function was assessed in terms of procoagulant activity (PCA) and tumour necrosis factor alpha (TNF-alpha) production. LPS-st imulated PCA increased after the first PE (P < 0.05). Stimulated TNF-a lpha production increased, but not significantly so. Similar effects w ere observed after the second and third PE (P < 0.05 for stimulated TN F-alpha). Values 48 h after the last PE were similar to those obtained before the second PE, suggesting that repeated infusions of HES had n o detrimental effect on monocyte function. Furthermore, plasma oncotic pressure was preserved after PE with HES. These results support the p artial replacement of costly human albumin with HES during repetitive PE, and suggest that HES might be a safe plasma expander in septic pat ients.