Aggressive resuscitation prevents gut ischemia due to intra-abdominal hypertension in LPS-induced shock

Introduction

Septic patients may develop intra-abdominal hypertension (IAH) with decreased SMA flow and gut ischemia. The effect of aggressive resuscitation on IAH and gut dysfunction in sepsis has not been well studied.

Hypothesis

Aggressive resuscitation in sepsis prevents gut ischemia despite IAH.

Methods

Seven pigs were used for intervention and three pigs served as controls. All pigs were sedated and ventilated, and arterial, PA and SMV catheters were inserted. SMA flow was measured with an intra-abdominal transonic flowmeter and IAP was measured directly. Intervention animals received 80 μg E. coli 0127:B8 LPS i.v. over 1 hour. Blood samples were taken and hemodynamics measured before and hourly after LPS. Saline and norepinephrine were used for resuscitation (target MAP > 65 mmHg, urine > 0.5 ml/kg/hour, mixed venous SO₂> 70%). SO₂ was maintained >85%. ANOVA analysis was used for result evaluation.

Results

After i.v. LPS administration, the animals developed shock and three succumbed after 6 hours. The MAP, CO, DO₂ and VO₂ were stable until animals were moribund. We saw a positive correlation between infused volume and IAP. The IAP exceeded 30 mmHg by 6 hours. However, the abdominal perfusion pressure, SMA flow and SMV lactate were unchanged as long as CO and CI were stable. CO and CI correlated inversely with SMV lactate. No changes in the IAP were observed in the control animals.

Table 1

Figure 1

Cardiac output versus SMV lactate.

Conclusion

Significant IAH develops in a model of LPS sepsis. However, gut ischemia is prevented by adequate CO and intestinal DO₂.