Utility of admission lactate concentration, lactate variables, and shock index in outcome assessment in dogs diagnosed with shock

Abstract

Objective:To determine whether admission venous plasma lactate concentration, calculated lactate variables, or shock index (SI) could discriminate hospital survivors from nonsurvivors in dogs admitted with shock. Design:Prospective investigation performed over a 19-month period.Setting: Large urban private teaching hospital.with initial peripheral venous plasma lactate concentration >2 mmol/L (18.0 mg/dL) and clinical and hemodynamic parameters consistent with shock. Interventions: None.Measurements and Main Results: Heart rate, systolic blood pressure, and venous plasma lactate concentrations were serially recorded at predefined time points and used to calculate SI (SI = heart rate/systolic blood pressure) and lactate variables, including lactime (time lactate > 2.0 mmol/L), lactate clearance ([lactate initial -lactate delayed ]/lactate initial × 100), and LAC AREA (area under the lactate concentration versus time curve). Primary outcome was survival to discharge.Overall survival rate was 61%. Admission venous plasma lactate concentration did not differ between groups (P = 0.2). Lactime was shorter in survivors versus nonsurvivors (P = 0.02). Lactate clearance at 1, 10, 16, 24, and 36 hours, and final lactate clearance were greater in survivors versus nonsurvivors (P < 0.05). LAC AREA at time intervals 0-1, 1-4, 4-10, 10-16, 16-24, 24-30, and 30-36 hours was larger in nonsurvivors versus survivors (P < 0.05). Total LAC AREA did not differ between groups (P = 0.09). Admission SI and time to normalize SI (SI < 0.9) were not different between survivors and nonsurvivors (P > 0.05). Conclusions:While admission venous plasma lactate concentration could not discriminate between hospital survivors and nonsurvivors, lactate variables showed clinical utility to predict outcome in dogs with shock. Further studies are needed to determine SI reference ranges and optimal SI cut-off values to improve its prognostic ability in sick dogs. K E Y W O R D Scanine, hypoperfusion, perfusion parameters, resuscitation Abbreviations: ED, emergency department; HR, heart rate; SI, shock index; SBP, systolic blood pressure.

Prospective evaluation of plasma lactate parameters for prognosticating dogs with shock

“…[34][35][36] The current study evaluating a cohort of dogs presenting to the ED with shock corroborated the association between persistent hyperlactatemia and non-survival that has been demonstrated in previous studies, showing that dogs with a longer lactime or lower degree of lactate clearance were more likely to die. 5,22,23,25 Furthermore, the majority of dogs that died or were euthanized in the current study failed to normalize venous plasma lactate concentration. Importantly, lactime remained significantly shorter in dogs that survived despite the confounding effect of early deaths leading to a shorter observation period for a subset of nonsurviving dogs.…”

“…Previous studies in dogs have demonstrated that lactate clearance has prognostic utility in dogs with sepsis, 21,38 IMHA, 16 GDV, 17 and babesiosis, 20 as well as in more general populations of critically ill horses and dogs. 25,29,39 Although most other previous veterinary studies evaluated lactate clearance variables at the 6-hour time interval, the current study instead included measured lactate variables at the 4and 10-hour intervals. These times were chosen in order to remain consistent with a previous publication that found significant differences in lactate variables at the 4-hour time point.…”

“…[22][23][24] Similarly, a recent study found that while persistent hyperlactatemia was associated with hospital mortality, admission venous plasma lactate concentration was not. 25 The purpose of the current study was to evaluate the clinical utility of admission venous plasma lactate concentration and serial lactate measures (lactime, lactate clearance, and LAC AREA ) in outcome prediction in dogs presenting to the ED with clinical signs of shock. An additional aim was to evaluate whether a higher illness severity score (ISS) (as measured by the APPLE fast score) was associated with higher initial lactate or inability to clear lactate.…”

“…This latter objective was meant to provide follow-up to a recent study undertaken by a subset of the current investigators that evaluated the prognosticating ability of lactate variables in dogs with shock but failed to stratify dogs by illness severity to determine if the degree of illness is associated with admission plasma lactate concentration or degree of lactate clearance. 25 For reporting purposes, parametric data were described with mean and standard deviation, and non-parametric data were described with median and range. A P-value of < 0.05 was deemed significant.…”

Postoperative Serum Lactate Levels for In-Hospital Mortality Prediction Among Heart Transplant Recipients

“…Serum lactate level measurements within the first 48 h after HTX were obtained from arterial blood gas analyses routinely assessed every 6 h. The observation made upon ICU admission was defined as the zero serum lactate measurement (Lac 0). Lactate clearance was calculated based on the equation: ([lactate initial -lactate delayed ]/lactate initial ×100) [6], and was determined for each patient individually throughout 3 different time frames: the first 24-h period (Lac clear 0-24) and the second 24-h period (Lac clear 24-48), and the first 48 h after surgery (Lac clear 0-48). The threshold for hyperlactatemia was set at >1.6 mmol/L, based on internal laboratory standardization.…”