Monitoring Splanchnic Hypoperfusion with Near-Infrared Spectroscopy in a Rabbit Model of Septic Shock

BACKGROUND: This study attempted to validate noninvasive monitoring using near-infrared spectroscopy at the splanchnic and hepatic level in an animal model of septic shock.
MATERIAL AND METHODS: New Zealand White rabbits were anesthetized, intubated, and vascular access was canalized. The animals were monitored with pulse oximetry, electrocardiography electrodes, temperature, invasive blood pressure, and regional hepatic and splanchnic oximetry using spectroscopy. Septic shock was induced with Escherichia coli toxin in the animals in the Case group. Invasive and non-invasive hemodynamic monitoring values were recorded every 15 min, and blood samples were extracted every 60 min. At 2 h, the animals were euthanized.
RESULTS: Systemic hypoperfusion data were recorded in the Case group: invasive arterial hypotension at 30 min of toxin inoculation, reduction in serum bicarbonate levels, reduction in base excess, and increase in lactic acid levels. When analyzing the noninvasive regional oximetry values, we found a reduction in splanchnic (at 30 min) and hepatic (at 60 min) levels.
CONCLUSIONS: Regional hepatic and splanchnic oxygenation is significantly related to the amount of invasive arterial pressure and biochemical variables of systemic hypoperfusion in a septic shock model. Changes in these values occurred earlier and were more marked in the measurement of regional splanchnic oxygenation.

Keywords: Sepsis, Spectroscopy, Near-Infrared, Splanchnic Circulation