Evaluation of tissue oxygen saturation in naturally occurring canine shock patients

Abstract

Objective: To measure tissue oxygen saturation (StO 2 ) in a population of dogs with naturally occurring shock and to evaluate the relationship of StO 2 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 2 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 2 values (65.12 ± 17.7%) than previously reported in experimental models of canine hemorrhagic shock.There was a moderate correlation between lower StO 2 and increasing Acute Patient Physiologic and Laboratory Evaluation scores. A single StO 2 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 2 values than those previously reported in dogs with experimentally induced shock. A lower initial StO 2 was associated with worse disease severity but was not a significant predictor of survival in this population. K E Y W O R D Sdogs, hypovolemia, illness severity, oxygenation indices

Hemorrhagic Shock Assessed by Tissue Microcirculatory Monitoring: A Narrative Review

“…When external interventions are artificially applied to experimental animals to cause shock, various experimental data may differ from the natural situation of shock. In another prospective study in dogs, Berg et al found that dogs in natural shock had lower initial StO 2 values than dogs with experimentally induced shock (32). In recent years, the method of near-infrared spectroscopy has been commonly used to monitor StO 2 , which enables noninvasive StO 2 monitoring to be performed at the bedside (57).…”