Introduction Pre-hospital identification of patients with suspected occult traumatic haemorrhage is problematic. Physiological parameters and clinical gestalt are inadequate surrogates for ongoing haemorrhage. Lactate monitoring may hold stronger predictive clinical utility to identify patients with suspected traumatic haemorrhage above other physiological parameters.

Methods A single centre, service evaluation of pre-hospital lactate monitoring. A point of care test was introduced into a Helicopter Emergency Medical Service in the United Kingdom. Clinicians adhered to strict education and governance, supported by standard operating procedure. Systolic blood pressure (SBP) and shock index (SI) was measured in patients that received pre-hospital transfusion therapy. A predetermined ‘cut off’ value of lactate >2.5 mmol was acknowledged. In-hospital follow up established further transfusion therapy.

Results Wilcoxon rank sum compared pre-lactate (n=22) and post-lactate (n=6) groups. Monte Carlo permutations were used to obtain exact probabilities. No statistically significant differences were found between groups for: SBP, p=0.955; and, SI, p=0.401. Univariate logistic regression identified the odds ratio (OR) and confidence interval (CI) for each continuous variable as: SBP, 0.97 (CI 0.94 to 1.01); SI, 26.91 (CI 1.11 to 652.48) and lactate >2.5 mmol, 2.33 (CI 0.23 to 23.91). Multivariate logistic regression identified OR as: SBP, 0.99 (CI 0.95 to 1.04); SI, 22.98 (CI 0.56 to 946.44); and lactate >2.5 mmol, 3.05 (CI 0.14 to 65.86).

Conclusion Lactate monitoring has been successfully introduced into an enhanced care service. The Results confirm SBP is not predictive of further transfusion. The OR for SI shows greater predictive power. Limited by a small dataset, the Results are hypothesis-generating only.