Objective: To assess the tissue oxygenation status and the effects of mechanical ventilation (MV) on oxygen dynamics in COPD patient with hypercapnia.
Methods: Gastric intramucosal pH (pHi) measured by gastric tonometer was examined in 19 patients before and after MV.
Results: pHi calculated before MV was 7.18 +/- 0.06; After receiving MV, pHi increased gradually until above 7.32 in 4 days; during weaning, there were no significant changes in pHi before and after discontinuation. The correlation analysis showed that there was no correlation between pHi and pHa (r = 0.352, P > 0.05), PgCO(2) and PaCO(2) (r = 0.421, P > 0.05), suggesting that pHi measurement would not be affected by hypercapnia.
Conclusions: Our study showed that tissue oxygenation insufficiency existed in COPD exacerbation stage. Gastric pHi may be used as the parameter to estimate tissue oxygenation status and a predictor of weaning from mechanical ventilation.