Predictive clinical utility of pre-hospital point of care lactate for transfusion of blood product in patients with suspected traumatic haemorrhage: derivation of a decision-support tool.

INTRODUCTION: Pre-hospital emergency medical teams can transfuse blood products to patients with suspected major traumatic haemorrhage. Common transfusion triggers based on physiological parameters have several disadvantages and are largely unvalidated in guiding pre-hospital transfusion. The addition of pre-hospital lactate (P-LACT) may overcome these challenges. To date, the clinical utility of P-LACT to guide pre-hospital blood transfusion is unclear. METHODS: A retrospective analysis of patients with suspected major traumatic haemorrhage attended by Air Ambulance Charity Kent Surrey Sussex (KSS) between 8 July 2017 and 31 December 2019. The primary endpoint was the accuracy of P-LACT to predict the requirement for any in-hospital (continued) transfusion of blood product. RESULTS: During the study period, 306 patients with suspected major traumatic haemorrhage were attended by KSS. P-LACT was obtained in 194 patients. In the cohort 103 (34%) patients were declared Code Red. A pre-hospital transfusion was commenced in 124 patients (41%) and in-hospital transfusion was continued in 100 (81%) of these patients, in 24 (19%) patients it was ceased. Predictive probabilities of various lactate cut-off points for requirement of in-hospital transfusion are documented. The highest overall proportion correctly classified patients were found for a P-LACT cut-point of 5.4 mmol/L (76.50% correctly classified). Based on the calculated predictive probabilities, optimal cut-off points were derived for both the exclusion- and inclusion of the need for in-hospital transfusion. A P-LACT < 2.5 mmol/L had a sensitivity of 80.28% and a negative likelihood ratio [LR-] of 0.37 for the prediction of in-hospital transfusion requirement, whereas a P-LACT of 6.0 mmol/L had a specificity of 99.22%, [LR-] = 0.78. CONCLUSION: Pre-hospital lactate measurements can be used to predict the need for (continued) in-hospital blood products in addition to current physiological parameters. A simple decision support tool derived in this study can help the clinician interpret pre-hospital lactate results and guide pre-hospital interventions in the major trauma patient.

Mortality of civilian patients with suspected traumatic haemorrhage receiving pre-hospital transfusion of packed red blood cells compared to pre-hospital crystalloid.

BACKGROUND: Major haemorrhage is a leading cause of mortality following major trauma. Increasingly, Helicopter Emergency Medical Services (HEMS) in the United Kingdom provide pre-hospital transfusion with blood products, although the evidence to support this is equivocal. This study compares mortality for patients with suspected traumatic haemorrhage transfused with pre-hospital packed red blood cells (PRBC) compared to crystalloid. METHODS: A single centre retrospective observational cohort study between 1 January 2010 and 1 February 2015. Patients triggering a pre-hospital Code Red activation were eligible. The primary outcome measure was all-cause mortality at 6 hours (h) and 28 days (d), including a sub-analysis of patients receiving a major and massive transfusion. Multivariable regression models predicted mortality. Multiple Imputation was employed, and logistic regression models were constructed for all imputed datasets. RESULTS: The crystalloid (n = 103) and PRBC (n = 92) group were comparable for demographics, Injury Severity Score (p = 0.67) and mechanism of injury (p = 0.73). Observed 6 h mortality was smaller in the PRBC group (n = 10, 10%) compared to crystalloid group (n = 19, 18%). Adjusted OR was not statistically significant (OR 0.48, CI 0.19-1.19, p = 0.11). Observed mortality at 28 days was smaller in the PRBC group (n = 21, 26%) compared to crystalloid group (n = 31, 40%), p = 0.09. Adjusted OR was not statistically significant (OR 0.66, CI 0.32-1.35, p = 0.26). A statistically significant greater proportion of the crystalloid group required a major transfusion (n = 62, 60%) compared to the PRBC group (n = 41, 40%), p = 0.02. For patients requiring a massive transfusion observed mortality was smaller in the PRBC group at 28 days (p = 0.07). CONCLUSION: In a single centre UK HEMS study, in patients with suspected traumatic haemorrhage who received a PRBC transfusion there was an observed, but non-significant, reduction in mortality at 6 h and 28 days, also reflected in a massive transfusion subgroup. Patients receiving pre-hospital PRBC were significantly less likely to require an in-hospital major transfusion. Further adequately powered multi-centre prospective research is required to establish the optimum strategy for pre-hospital volume replacement in patients with traumatic haemorrhage.

[Magnetic resonance tomographic study of aortic isthmus stenosis]. / Kernspintomographische Untersuchung der Aortenisthmusstenose.

We present four patients with coarctation of the aorta, whose work-up was facilitated by MRI. Magnetic resonance has the potential for displacing angiography in imaging these patients.

[CT diagnosis of cystic hygroma]. / CT-Diagnose des zystischen Hygroms.

We present five patients with cystic hygroma: the CT features are presented. It occurs primarily in the region of the neck. Occasional involvement of the axilla, the chest wall and the mediastinum is possible.