Acute peritonitis leads to early remote microvascular dysfunction

Introduction

Remote organ injury, as evidenced by loss of functional capillaries and impaired microvascular function, has been demonstrated in a resuscitated normotensive 24-h chronic model of intra-abdominal sepsis [1,2]. Our objective has been to develop an acute intra-abdominal model of sepsis which can be used to observe the temporal evolution of this remote microvascular dysfunction.

Methods

Twenty-eight male Sprague Dawley rats were randomised to either sham (SH) laparotomy or modified caecal ligation and perforation (CLP) and divided into three experimental groups. Haemodynamic variables were monitored for 4-h post laparotomy in all animals. Group A (n = 8) provided microbiological and haematological data prior to and 4-h post laparotomy. Group B (n = 10) provided blood lactate data at 4-h post laparotomy. Group C (n = 10) proceeded to intravital microscopy of the hind limb to asses the effect of acute normotensive sepsis at 1 and 4-h on capillary blood flow in a remote organ.

Results

Data are reported as mean ± SEM. Blood and haemodyanmic data were compared between groups and by time using ANOVA (SPSS v8.0). Capillary density measurements were analyzed using Repeated Measures ANOVA (SPSS v8.0). Blood cultures from all CLP animals were positive for a combination of E. coli, Proteus and Bacteroides. There were no differences in haemodynamics or arterial blood gases between CLP or SH animals at different time points. However, there were significant differences in white blood cell count (WBC's), blood lactate and stopped capillary flow (CD_stop) density measurements between the groups (Table).

Conclusion

In this acute model of sepsis remote organ damage occurs early and is equivalent to that seen at 24 h. Therapies aimed at MODS prevention need to be commenced at the first possible opportunity.

Table