The influence of different levels of PEEP on peripheral tissue perfusion measured by subcutaneous and transcutaneous oxygen tension

Objective To compare subcutaneous (PscO₂) and transcutaneous (PtcO₂) oxygen tension measurements in relation to hemodynamic variables at different levels of PEEP, and to evaluate the usefulness of these measurements as monitors of peripheral tissue perfusion.Design Prospective trial.Setting Intensive care unit in a university hospital.Patients Seven patients with gastric cancer who where undergoing total gastrectomy.Interventions Silicone catheter was placed in the upper arm and transcutaneous oxygen monitor was placed on the upper part of the chest. A pulmonary artery catheter was placed in the right pulmonary artery.Measurements and results PscO₂ and PtcO₂ together with hemodynamic variables were measured at different levels of PEEP. Progressive increase of PEEP reduced cardiac index (CI) (p<0.05) with a concomitant decrease of PscO₂ (p<0.05) and oxygen delivery (DO₂) (p<0.05). Changes in PtcO₂ parallelled changes in arterial oxygen tension (PaO₂), but no correlation was found between PtcO₂, CI and DO₂.Conclusion PscO₂ is a sensitive indicator of subcutaneous tissue perfusion, which can be used to identify the PEEP level, with optimum peripheral perfusion. PscO₂ seems to be a more reliable indicafor of tissue perfusion than PtcO₂.This study was supported by Tore Nilsons Fund for Medical Research. Lundgrens Stiftelse, Medical Faculty, University of Lund and by the Swedish Medical Research Council Projecr no. B88-17x-00640-24B