Various vasoactive substances are involved in the regulation of the macro- and microcirculation. We have investigated if these regulators change during long-term volume
therapy with
human albumin (HA) or hydroxyethylstarch
solution (HES) in
trauma and
sepsis patients. To maintain pulmonary capillary wedge pressure (PCWP)
at 10-15 mm Hg, either 20% HA (HA-
trauma, n = 14; HA-
sepsis, n = 14) or 10% low-molecular weight HES
solution (HES-
trauma, n = 14; HES-
sepsis, n = 14) were infused for 5 days, otherwise patient management did not differ between the two groups (
trauma/
sepsis). Mean arterial pressure (MAP), heart rate (HR), PCWP and cardiac index (CI) were monitored in all patients. Liver function was assessed using the
monoethylglycinexylidide (
MEGX) test, and gastric intramucosal pH (pHi) was monitored by tonometry to assess splanchnic perfusion. Plasma concentrations of
vasopressin,
endothelin-1,
adrenaline,
noradrenaline,
atrial natriuretic peptide and 6-keto-prostaglandin F1 alpha were measured from arterial blood samples. All measurements were carried out on the day of admission to the intensive care unit (
trauma patients) or on diagnosis of
sepsis, and daily over the next 5 days at 12:00. MAP, HR and PCWP did not differ between the corresponding subgroups (
trauma/
sepsis). Cl increased significantly more in the HES than in the HA groups. pHi and
MEGX plasma concentrations did not differ in the
trauma patients throughout the study. Both were lower than normal in the
sepsis groups and increased more markedly in the HES than in the
albumin-treated patients (P < 0.05). In the
trauma patients, concentrations of all vasoactive regulators were very similar in both groups. In both
sepsis groups, vasopressors (
vasopressin,
endothelin-1,
noradrenaline and
adrenaline) were significantly increased above normal at baseline and decreased more markedly in HES than in HA patients. Concentrations of
atrial natriuretic peptide increased only in the HA patients (from 159 (
SD 31) to 215 (38) pg ml-1 on day 2). Plasma concentrations of 6-keto-prostaglandin F1 alpha decreased significantly only in the HES
sepsis patients (from 112 (25) to 47 (15) pg ml-1).