Evaluation of tissue oximetry in perioperative monitoring of colorectal surgery

Twenty patients undergoing elective colorectal surgery were studied during and after operation by means of tissue oximetry measuring the subcutaneous partial pressure of oxygen (PscO2) and by gastric intramural pH measurement. Mean(s.d.) PscO2 recorded 24 h after surgery was significantly lower than the peroperative value: 14(10) versus 24(14) mmHg, P less than 0.02. The postoperative PscO2 was also significantly lower than that measured in a control group of ten healthy volunteers: 14(10) versus 34(18) mmHg, P less than 0.001. The peroperative PscO2 of the patients who developed a postoperative complication was significantly lower than that of those who had an uneventful postoperative clinical outcome: 16(9) versus 32(14) mmHg, P less than 0.02. The peroperative PscO2 of the patient group with complications was also significantly lower than that of the control group: 16(9) versus 34(18) mmHg, P less than 0.02. The peroperative PscO2 of the group of patients without complications was almost identical to that of the control group. During operation only one patient developed gastric intramural acidosis. Perioperative oxygen debt and the response of subcutaneous tissue oxygen tension to oxygen breathing seemed to correlate better with clinical outcome than gastric wall pH values and the conventional parameters of tissue perfusion.