Evaluation of tissue oxygen saturation in naturally occurring canine shock patients.

OBJECTIVE

To measure tissue oxygen saturation (StO ) in a population of dogs with naturally occurring shock and to evaluate the relationship of StO with an established veterinary severity scoring system (Acute Patient Physiologic and Laboratory Evaluation) and patient survival.

DESIGN

Prospective observational study.

SETTING

University teaching hospital.

ANIMALS

Twenty-five adult dogs presenting in shock, as determined by the presence of hypotension, the calculated shock index, and hyperlactatemia.

INTERVENTIONS

StO was measured prior to any therapeutic interventions. Blood samples were also collected for measurement of plasma lactate, complete blood count, and a serum biochemical profile. Abdominal and thoracic focused assessment with sonography was also performed.

MEASUREMENTS AND MAIN RESULTS

Dogs enrolled in this study had lower mean (±SD) StO values (65.12 ± 17.7%) than previously reported in experimental models of canine hemorrhagic shock. There was a moderate correlation between lower StO and increasing Acute Patient Physiologic and Laboratory Evaluation scores. A single StO value, assessed prior to therapeutic intervention, was not a sensitive predictor of mortality in this population.

CONCLUSIONS

Dogs with naturally occurring shock have lower mean StO values than those previously reported in dogs with experimentally induced shock. A lower initial StO was associated with worse disease severity but was not a significant predictor of survival in this population.