Abstract: SA-PO035

Effects of Fluid Resuscitation on Macro and Microcirculatory Perturbations in Ovine Septic Shock

Session Information

Category: Acute Kidney Injury

  • 003 AKI: Clinical and Translational

Authors

  • Lankadeva, Yugeesh Ryan, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, New South Wales, Australia
  • Kosaka, Junko, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, New South Wales, Australia
  • Iguchi, Naoya, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, New South Wales, Australia
  • Evans, Roger G, Monash University, Melbourne, New South Wales, Australia
  • Booth, Lindsea C., Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, New South Wales, Australia
  • Bellomo, Rinaldo, Austin Health, Melbourne, New South Wales, Australia
  • May, Clive N., Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, New South Wales, Australia
Background

Aggressive fluid resuscitation, with multiple boluses of crystalloids remains the first-line intervention to maintain systemic hemodynamics in septic shock, but its effects on the renal microcirculation are unknown. We therefore examined the effects of three successive boluses of sodium lactate on intra-renal and urinary oxygenation (pO2) in conscious sheep with established septic acute kidney injury (AKI).

Methods

Sheep were instrumented with fiber-optic probes in the renal cortex, medulla and within a bladder catheter. Sheep received an infusion of Escherichia coli or vehicle-saline for 30 hours. A 500-mL bolus of sodium lactate was infused intravenously every hour at 24, 25 and 26 h of sepsis (N=8) over 15 min time-intervals.

Results

Septic AKI was characterized by hypotension (80±2 to 68±2 mmHg) and reduced creatinine clearance (82±8 to 40±6 mL/min)) (both P<0.01). Medullary tissue pO2 (43±4 to 19±4 mmHg) and urinary pO2 (44±4 to 20±3 mmHg) were simultaneously reduced (both P<0.001). Infusion of crystalloids briefly increased blood pressure (to 74±6 mmHg), creatinine clearance (to 71±16 mL/min) and improved medullary pO2 (to 35±4 mmHg) and urinary pO2 (to 28±6 mmHg). These effects were short-lived and rapidly diminished within the 3-h recovery period. Sheep with septic AKI retained 70% of the total volume of crystalloids infused.

Conclusion

Infusion of three successive boluses of crystalloids briefly reversed renal medullary hypoxia and improved kidney function in septic AKI. However, the transient nature of these effects challenges the long-term benefits of aggressive volume resuscitation in septic shock. In septic AKI, excessive fluid retention may lead to increased cardiac filling pressures and tissue oedema. Urinary pO2 may be a real-time surrogate marker of medullary tissue pO2 during fluid resuscitation in septic AKI.

Funding

  • Government Support - Non-U.S.