Shock index is associated with mortality in canine vehicular trauma patients.

OBJECTIVE: To calculate and compare shock index (SI) in healthy dogs and vehicular trauma dogs (VT), determine the prognostic value of SI in VT dogs, and to assess the correlation between SI and the animal trauma triage score, modified Glasgow Coma Scale score, and lactate in VT dogs. DESIGN: Retrospective study from April 2016 to February 2018. SETTING: Twenty-four-hour tertiary referral level II trauma center. ANIMALS: One hundred twenty-one dogs presented to the emergency service for VT and 60 healthy control dogs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Heart rate and systolic blood pressure were measured on each patient and used to calculate SI. SI was significantly higher in VT dogs compared to healthy control dogs (median SI, 1.0 vs 0.75; P < 0.0001). SI was significantly higher in those that died versus those that survived to discharge (median, 1.27 vs 0.96; P = 0.017). SI positively correlated with animal trauma triage score (95% confidence interval, 0.039-0.49; P = 0.019; r = 0.26) but did not with plasma lactate level at presentation (P = 0.068; r = 0.22) or modified Glasgow Coma Scale (P = 0.85; r = -0.021, 95% confidence interval, -0.24 to 0.20). CONCLUSIONS: SI is easy to calculate during triage of a trauma patient. Given its significant relationship with mortality, higher SIs should prompt the clinician to pursue additional monitoring, diagnostics, and intervention.

Determination of strong ion gap in healthy dogs.

OBJECTIVE: To determine and compare reference intervals of the strong ion gap (SIG) in a group of healthy dogs determined with 2 different equations. DESIGN: Prospective observational study. SETTING: Tertiary referral and teaching hospital. ANIMALS: Fifty-four healthy dogs. INTERVENTIONS: None. MEASUREMENTS: Serum biochemistry and blood gas analyses were performed for each dog. From these values, SIG was calculated using 2 different equations: SIG(1) = SID(a) {[Na (+)] + [K(+)] - [Cl(-)]+ [2 × Ca(2+)] + [2 × Mg(2+)] - [L-lactate]}- SID(e) {TCO(2) + A(-)} and SIG(2) = [albumin] × 4.9-anion gap. Reference intervals were established for each SIG equation using the mean ± 1.96 × standard deviation (SD). RESULTS: For SIG(1), the median was 7.13 mEq/L (range, 1.05-11.30 mEq/L) and the derived reference interval was 1.85-10.61 mEq/L. Median SIG(2) was -0.22 mEq/L (range, -5.34-6.61 mEq/L) and the mean SIG(2) was -0.09 mEq/L (95% confidence interval for the mean, -0.82-0.65 mEq/L). The derived reference interval was -5.36-5.18 mEq/L. The results of the SIG calculations were significantly different (P < 0.0001) between the 2 equations used. CONCLUSION: The 2 equations used to calculate SIG yielded significantly different results and cannot be used interchangeably. The authors believe SIG(2) to be a more accurate reflection of acid-base status in healthy dogs, and recommend that this calculation be used for future studies.