Search

The aims of this study were to determine the normal range of tissue oxygenation (SO(2)) in the "mature" colostomy stomacolostomy stoma and to investigate whether there were any diurnal variationsdiurnal variations in the SO(2) 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 SO(2) Tissue SO(2) was measured on the stoma using visible wavelength spectroscopy (Whitland RM 200, Whitland Research, Whitland, 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 SO(2) in the colostomy stoma was 77.6 +/- 6.8 and there were no differences in the SO(2) measurements between the baseline, 6 h and the 24 h values. There were also no differences in the SO(2) values between the four quadrants of the stomas. In conclusion, visible wavelength spectrophotometry can reliably measure stomal SO(2) in a non-invasive way. No significant diurnal variations in the stomal SO(2) values were detected.

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 (Whitland RM 200, Whitland Research, Whitland, 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.

Recently lightguide spectrophotometry (LGS) has been investigated for assessing bowel mucosal oxygenation and may prove helpful in the diagnosis of bowel ischaemia. This pilot study explores the use of LGS and laser Doppler flowmetry (LDF) to measure SO2 and perfusion in the bowel during key stages of colon surgery. SO2 and perfusion in the mucosal and serosal layers of the rectum, sigmoid and descending colon were measured in 7 patients by LGS (Whitland Research, UK) and LDF (Moor Instruments, UK) respectively at four stages (baseline, after mobilisation of the sigmoid, after ligation of the inferior mesenteric artery (IMA) and after complete devascularisation of the sigmoid). The sigmoid mucosal SO2 and LDF values were significantly lower than the baseline after the ligation of IMA and devascularisation. Mean (SD) baseline sigmoid mucosal SO2 (73%) decreased to 55% after ligation of IMA and to 39% after complete devascularisation. The sigmoid serosal SO2 did not show any change after ligation of IMA and showed only 7% decrease after devascularisation. There was no difference in baseline SO2 and LDF values in different parts of the bowel but the mean mucosal baseline SO2 (75%) was significantly lower than that in the serosa (87%). In conclusion, mucosal SO2 measurements can accurately diagnose bowel ischaemia but serosal SO2 does not reflect mucosal ischaemia.

Recently lightguide spectrophotometry (LGS) has been investigated for assessing bowel mucosal oxygenation and may prove helpful in the diagnosis of bowel ischaemia. This pilot study explores the use of LGS and laser Doppler flowmetry (LDF)to measure SO2 and perfusion in the bowel during key stages of colon surgery. SO2 and perfusion in the mucosal and serosal layers of the rectum, sigmoid and descending colon were measured in 7 patients by LGS (Whitland Research, UK) and LDF (Moor Instruments, UK) respectively at four stages (baseline, after mobilisation of the sigmoid, after ligation of the inferior mesenteric artery (IMA) and after complete devascularisation of the sigmoid). The sigmoid mucosal SO2 and LDF values were significantly lower than the baseline after the ligation of IMA and devascularisation. Mean (SD) baseline sigmoid mucosal SO2 (73%) decreased to 55% after ligation of IMA and to 39% after complete devascularisation. The sigmoid serosal SO2 did not show any change after ligation of IMA and showed only 7% decrease after devascularisation. There was no difference in baseline SO2 and LDF values in different parts of the bowel but the mean mucosal baseline SO2 (75%) was significantly lower than that in the serosa (87%). In conclusion, mucosal SO2 measurements can accurately diagnose bowel ischaemia but serosal SO2 does not reflect mucosal ischaemia.

Use of Visible Light Spectrophotometry (VLS) and Laser Doppler Flowmetry (LDF) is currently being studied by the authors to assess the viability of tissue margins in colon resection and to assess mucosal oxygenation in the colon. Thus, as a preliminary study it was necessary to evaluate whether there is any systematic inter-probe variability of the measurements by VLS and LDF. The oral mucosa was used as a model.