Septic shock in dogs: clinical features and prognostic significance.

Introduction: septic shock is a subset of sepsis characterized by significantly increased mortality in people. A novel proposed classification of septic shock based on 3 different phenotypes (cryptic, hyperlactatemia without persistent hypotension; vasoplegic, persistent hypotension without hyperlactatemia; and dysoxic, persistent hyperlactatemia and hypotension) seems helpful for outcome prediction. Our aim was to report the clinical features and outcome of dogs with septic shock, including the prevalence of the 3 different septic shock phenotypes, compared to dogs with uncomplicated sepsis. Methods: Dogs with sepsis, identified as SIRS plus confirmation of infection, and hospitalized in the intensive care unit were prospectively included (June 2018 –December 2019). Presence of septic shock was defined by persistent hypotension requiring vasopressor therapy or persistent hyperlactatemia after adequate fluid resuscitation Dogs with septic shock were further classified as affected by cryptic, vasoplegic, or dysoxic shock according to the previously cited human criteria. The canine Acute Patient Physiological and Laboratory Evaluation (APPLEfast) score was calculated and the presence of multiorgan dysfunction syndrome (MODS), defined as previously reported for dogs, was evaluated upon admission in the whole population. Nonparametric statistical tests were performed, and significance set at P < 0.05. Results: One-hundred-thirty-one septic dogs were enrolled; 31/131 (24%) had septic shock: cryptic (10/31, 32%), dysoxic (18/31, 58%), and vasoplegic (3/31, 10%). Septic shock dogs had significantly higher APPLEfast Scores (28, 13-38 vs 25, 6-33, P = 0.0051) and plasma lactate (3.5, 1.3-9.9 vs 2.2, 0.4-7.1, P < 0. 001), and significantly greater frequencies of MODS (74.2% vs 7%, P <0. 001) and death (64.5% vs 24%, P < 0.001) compared to patients with uncomplicated sepsis (n = 100). There was no significant difference in the investigated variables, including mortality rate (cryptic, 60%; dysoxic, 67%; vasoplegic shock, 67%), among the 3 different phenotypes of septic shock. Conclusions: canine septic shock is associated with greater disease severity, occurrence of MODS, and higher mortality compared to uncomplicated sepsis. Dysoxic shock was the most prevalent phenotype of septic shock reported; however, the incidence and the prognostic relevance of the 3 septic shock phenotypes need to be addressed in larger study populations.