Aggressive and moderate fluid resuscitation in septic pigs: consequences on morbidity

Introduction

While early aggressive fluid administration has been associated with improved outcome in sepsis [1], this approach may increase the risk of lung edema and abdominal compartment syndrome when capillary permeability is increased. The aim of this study was to test two different approaches of volume resuscitation in septic animals.

Methods

Thirty pigs were anaesthetized and invasively monitored (systemic and regional flows and pressures). They were randomized to control, moderate volume (C; n = 7), control, high volume (CH; n = 8), peritonitis, moderate volume (P; n = 8) and peritonitis, high volume (PH; n = 7). Peritonitis was induced by instillation of 1 g/kg autologous faeces dissolved in glucose solution. Ventilation was adjusted to maintain an arterial pO₂ >100 mmHg. Groups CH and PH received 15 ml/kg/hour Ringer's solution plus 5 ml/kg/hour HES 6%, whereas groups C and P received 10 ml/kg/hour Ringer's solution. If clinical signs of hypovolaemia were present, additional boluses of HES 6% (maximally 100 ml/hour) were given. The animals were treated and observed for 24 hours or until death.

Results

Cardiac output was higher in group PH as compared with the other groups (P < 0.05), while mean arterial pressure was similar in all groups. While the oxygenation index (paO₂/FiO₂) decreased in all groups, group PH had the lowest values after 6 hours and throughout the rest of the experiments (P < 0.05) (Figure 1). Survival was lowest in group PH, followed by group P, while all animals in the control groups survived until 24 hours (Figure 2).

Figure 1

Oxygenation index.

Figure 2

Survival proportion.

Conclusion

High-volume administration decreased oxygenation and survival in peritonitis but not in control animals. A high-volume approach may not be generally beneficial in abdominal sepsis.