Plasma lactate concentrations in septic peritonitis: A retrospective study of 83 dogs (2007-2012).

OBJECTIVE: To determine if absolute plasma lactate concentration or lactate clearance in dogs with septic peritonitis is associated with morbidity or mortality. DESIGN: Retrospective cohort study from 2007 to 2012. SETTING: University teaching hospital. ANIMALS: Eighty-three dogs with septic peritonitis were included. Patients had at least 1 plasma lactate measurement during the course of the hospitalization. RESULTS: Sixty-four percent of the patients survived to discharge, 22% were euthanized, and 14% died during hospitalization. Plasma lactate concentration >2.5 mmol/L on admission (29% of the patients) was associated with mortality (P = 0.001). Median admission plasma lactate concentration (n = 81) was significantly different between nonsurvivors (2.5 mmol/L, range 0.5-8.4) and survivors (1.4 mmol/L, range 0.5-9.7; P = 0.007). Admission plasma lactate concentration >4 mmol/L yielded a sensitivity of 36% and a specificity of 92% for nonsurvival. The inability to normalize plasma lactate concentration within 6 hours of admission (n = 10/24) yielded a sensitivity of 76% and specificity of 100% for nonsurvival. Postoperative hyperlactatemia (plasma lactate concentration >2 mmol/L; n = 18/76) had a sensitivity of 46% and specificity of 88% for nonsurvival. Persistent postoperative hyperlactatemia (n = 11/18) had a sensitivity of 92% and a specificity of 100% for nonsurvival. Lactate clearance less than 21% at 6 hours (n = 20) had a sensitivity of 54% and specificity of 91% for nonsurvival. Lactate clearance less than 42% at 12 hours (n = 18) had a sensitivity of 82% and a specificity of 100% for nonsurvival. CONCLUSIONS: Admission plasma lactate concentration and lactate clearance were good prognostic indicators in dogs with septic peritonitis.