Reliability of measurement techniques for the hepato-splanchnic region in multiple-trauma patients

Relevant information on the adequacy of intestinal perfusion is needed. The objective of our study was to investigate the relationship between the difference in intra-mucosal and arterial CO₂ pressure (pCO₂ gap) and the outcome in multiply injured patients and relations between the pCO₂ gap and intestinal permeability (IP).

Forty consecutive multiply injured patients, admitted to the intensive care unit (ICU) of the University Medical Centre Ljubljana, were studied prospectively. On days 2 and 4, IP was measured using the lactulose–mannitol (L/M) test. For 4 days, the pCO₂ gap was measured using air tonometry. Multiple organ failure (MOF) scores were calculated daily.

No significant differences in the MOF scores and length of ICU stay were found between the groups formed with respect to the presumably normal pCO₂ gap value of 1.33 kPa. The baseline pCO₂ gap difference in patients with abdominal injuries was significantly (p = 0.01) higher in comparison with those without abdominal injuries. There was no correlation between the pCO₂ gap values and L/M index measured simultaneously and also between the baseline and average pCO₂ gap and L/M index measured on days 2 and 4. We were unable to find any association between the MOF score and pCO₂ gap. The MOF score, however, correlated significantly with the L/M value determined on day 4 (r = 0.85, p = 0.02). The average gastric retention volume was inversely correlated with the average pCO₂ gap (r = −0.33, p = 0.04).

The pCO₂ gap in trauma patients on intra-gastric enteral nutrition in the phase of present technical solutions has no prognostic value for the development of MOF, but IP correlated with it.