Evaluation of skin viability in dogs, using transcutaneous carbon dioxide and sensor current monitoring

Transcutaneous oxygen monitoring is commonly used in human beings to assess skin viability. Little attention has been directed toward the use of transcutaneous carbon dioxide (PCO2-TC) monitoring for the same purpose. The application of PCO2-TC monitoring for evaluating skin viability in dogs was investigated. The changes in PCO2-TC and local power reference (LPR) values were measured from 16 skin flaps created along the lateral hemithoraces of 4 dogs. Transcutaneous PCO2 and LPR values were serially recorded from the base and apex of each flap for 12 hours. A single measurement was obtained from each flap base and apex 24 hours after surgery. Arterial blood gas analyses were obtained to compare central PCO2 values with peripheral skin PCO2 values. The flaps were observed for 4 days and then harvested for histologic examination. Full-thickness skin biopsy specimens were obtained 24 hours after surgery and when the flaps were harvested to evaluate the viability of the apex and base of the flaps. A subjective grade was assigned to all skin biopsy specimens during histologic examination. For all measurements, a significant difference was found between the PCO2-TC values for apices and bases of the flaps. The mean PCO2-TC for all bases was 52.66 mm of Hg +/- 2.24 (SEM), and the mean PCO2-TC for all apices was 106.4 mm of Hg +/- 2.44. The regional carbon dioxide index (apex PCO2-TC/base PCO2-TC) was 2.02. A significant difference was not found between the LPR values for bases and apices.(ABSTRACT TRUNCATED AT 250 WORDS)