Somatosensory evoked potentials as predictor of systemic inflammatory response syndrome in pigs?

Sepsis or systemic inflammatory response syndrome (SIRS) is often associated with encephalopathy (70%), which has been described as an early symptom resulting in several diseases. The present study investigated somatosensory evoked potentials (SEP) as an indicator or even a predictor of cerebral dysfunction evaluated in an experimental model of SIRS in pigs.

Eight Göttinger minipigs were included in the study. SIRS was mediated by induction of pancreatitis due to injection (ductus pancreaticus) of 500 mg/kg sodium taurocholate and 2.5 IU/kg enterokinase. Monitored parameters were: arterial blood-central venous-pulmonary arterial pressure, and cardiac output, systemic vascular resistance, and body temperature. SEP were recorded from centroparietal vs. frontal areas after electrical stimulation of the right forepaw.

At least 33% loss of vascular resistance from baseline (SIRS criteria) occurred in all animals within 4-18 h. Baseline recordings in all anesthetized animals indicated primary cortical responses to electrical stimuli identified by peak latencies between 15-20 ms (SEP(P15-20)). Attenuations in the amplitudes with significant median decreases of 46% were observed at least 4 h before the defined hemodynamic SIRS criteria.

The present data show a trend for the attenuation in SEP amplitudes as an indicator of systemic inflammatory response. SEP monitoring may be a sensitive marker of developing early changes in cerebral function due to SIRS-related encephalopathy.