Use of Visible Spectrophotometry to Assess Tissue Oxygenation in the Colostomy Stoma

The aims of this study were to determine the normal range of tissue oxygenation (SO2) in the "mature" colostomy stoma and to investigate whether there were any diurnal variations in the SO2 values. Ten patients with an end colostomy for a minimum duration of three months and using conventional colostomy bags were included in this study. Tissue SO2 was measured on the stoma using visible wavelength spectroscopy (Whit land RM 200, Whit land Research, Whit land, UK) The measurements were carried out on each patient on three occasions: the first early in the morning (designated "baseline"), a second after 6 h and the third on the next day at 24 h. The results showed that the mean baseline SO2 in the colostomy stoma was 77.6 +/- 6.8 and there were no differences in the SO2 measurements between the baseline, 6 h and the 24 h values. There were also no differences in the SO2 values between the four quadrants of the stomas. In conclusion, visible wavelength spectrophotometry can reliably measure stomal SO2 in a non-invasive way. No significant diurnal variations in the stomal SO2 values were detected.