Clearance of serum solutes by hemofiltration in dogs with severe heat stroke

Abstract

Background: We have previously reported that hemofiltration (HF) may be an effective additional means of treating heat stroke when rapid cooling is not effective. Methods: Dogs were assigned to a heat stroke (control) or heat stroke + hemofiltration (HF) group (n = 8 each group). After heat stroke induction, dogs in the HF group received HF for 3h. Serum concentrations of interleukin (IL)-10, tumor necrosis factor (TNF)-aα, IL-6, blood urea nitrogen (BUN) and creatinine were measured at baseline and 1, 2, and 3h after heat stroke. Clearance rates of solutes were determined 1, 2, and 3h after the start of HF. Results: Serum concentrations of all solutes tended to increase with time after heat stroke in the control group, but decreased (BUN, creatinine) or remained relatively unchanged (TNF-aα, IL-6, IL-10) with time in the HF group. Concentrations of all solutes were significantly lower in the HF group compared with the control group at 2 and 3h (P < 0.05). Clearance rates for small molecular weight solutes were high, while those for larger molecular weight solutes were low. Conclusion: HF prevents heat stroke-induced increases in serum cytokine concentrations and is effective for clearing small molecular weight solutes from serum, but less effective for clearing larger molecular weight solutes, including TNF-aα, IL-6, and IL-10.