Forgot calcium? Admission ionized-calcium in two civilian randomized controlled trials of prehospital plasma for traumatic hemorrhagic shock.

BACKGROUND: Randomized clinical trials (RCTs) support the use of prehospital plasma in traumatic hemorrhagic shock, especially in long transports. The citrate added to plasma binds with calcium, yet most prehospital trauma protocols have no guidelines for calcium replacement. We reviewed the experience of two recent prehospital plasma RCTs regarding admission ionized-calcium (i-Ca) blood levels and its impact on survival. We hypothesized that prehospital plasma is associated with hypocalcemia, which in turn is associated with lower survival. METHODS: We studied patients enrolled in two institutions participating in prehospital plasma RCTs (control, standard of care; experimental, plasma), with i-Ca collected before calcium supplementation. Adults with traumatic hemorrhagic shock (systolic blood pressure ≤70 mm Hg or 71-90 mm Hg + heart rate ≥108 bpm) were eligible. We use generalized linear mixed models with random intercepts and Cox proportional hazards models with robust standard errors to account for clustered data by institution. Hypocalcemia was defined as i-Ca of 1.0 mmol/L or less. RESULTS: Of 160 subjects (76% men), 48% received prehospital plasma (median age, 40 years [interquartile range, 28-53 years]) and 71% suffered blunt trauma (median Injury Severity Score [ISS], 22 [interquartile range, 17-34]). Prehospital plasma and control patients were similar regarding age, sex, ISS, blunt mechanism, and brain injury. Prehospital plasma recipients had significantly higher rates of hypocalcemia compared with controls (53% vs. 36%; adjusted relative risk, 1.48; 95% confidence interval [CI], 1.03-2.12; p = 0.03). Severe hypocalcemia was significantly associated with decreased survival (adjusted hazard ratio, 1.07; 95% CI, 1.02-1.13; p = 0.01) and massive transfusion (adjusted relative risk, 2.70; 95% CI, 1.13-6.46; p = 0.03), after adjustment for confounders (randomization group, age, ISS, and shock index). CONCLUSION: Prehospital plasma in civilian trauma is associated with hypocalcemia, which in turn predicts lower survival and massive transfusion. These data underscore the need for explicit calcium supplementation guidelines in prehospital hemotherapy. LEVEL OF EVIDENCE: Therapeutic, level II.

An online survey of small animal veterinarians regarding current fluid therapy practices in dogs and cats.

OBJECTIVE To determine common fluid therapy practices of small animal practitioners and identify fluid therapy-related knowledge gaps that may benefit from improved educational efforts, targeted research, or both. DESIGN Online survey. SAMPLE 1,496 small animal veterinarians PROCEDURES An online survey was provided to members of the Veterinary Information Network between December 23, 2013, and January 30, 2014. The survey consisted of 24 questions investigating the administration of crystalloid and synthetic colloid solutions, but not blood products, and focused primarily on the choice of fluid type, frequency of administration, type of patient treated with fluids, treatment with fluids subcutaneously versus IV, and potassium supplementation of fluids. Only responses from practicing small animal veterinarians were included. Not all respondents answered every question, and some questions allowed > 1 answer. RESULTS Balanced crystalloid solutions were the most common fluid type in all clinical scenarios described. The most common maintenance IV fluid rate reported by respondents (762/1,333 [57%]) was 60 mL/kg/d (27 mL/lb/d); calculation of fluid administration rate by means of body surface area was infrequent. Challenges of fluid therapy included determining the appropriate rate (572/1,496 [38%]) and fluid type (497/1,496 [33%]) and determining the need for potassium supplementation (229/1,496 [15%]). CONCLUSIONS AND CLINICAL RELEVANCE Small animal veterinarians tended to favor isotonic balanced crystalloid solutions for IV fluid therapy, compared with other common choices such as isotonic saline (0.9% NaCl) solution. Despite its ubiquity, respondents found many aspects of fluid therapy to be challenging, suggesting the need for easy to use, evidence-based guidelines.