Is Lactate an effective clinical marker of outcome for children with major trauma?

This report focuses on the work undertaken during the first year study of a PhD at the University of Southampton. The report will examine the pertinent literature surrounding the research topic, identify gaps in the research and then offer an evolving research question. A suggested research methodology will be discussed. The assessment and treatment of severely injured children can be stressful for all involved. The aim of this study is to add to the body of knowledge, and maybe generate new theories regarding how children react to both penetrating and blunt trauma.

Blunt and penetrating trauma in children in the United Kingdom is thankfully still relatively rare. However, It has been noted that trauma is the second biggest killer of children in United Kingdom behind neoplasms (ONS 2013).  Due to anatomical and physiological differences, children have very efficient compensatory mechanisms. Approximately 30% of their circulating blood volume can be lost before there is a drop in blood pressure. Other vital signs, of heart rate, capillary refill and respiratory rate can be altered due to psychological, and environmental factors and not due to blood loss, calling into question their sensitivity. This can lead to the child being incorrectly assessed as to the severity of their injuries, and either be over or under resuscitated neither an ideal outcome.

Due to conflicts in Afghanistan and Iraq there has been considerable advances in the care of the traumatized adult. In particular there has been an increase use of biochemical markers as an indicator of shock. Lactate being the one such maker, as it is commonly available in routine blood tests. Lactate is known to be a bi-product of anaerobic metabolism and it has been suggested than an increase in the traumatized adult can be an indicator of occult hypoperfusion and occult bleeding. There is also evidence to suggest that the time it takes the body to clear the lactate could be an indicator and predictor of mortality and morbidity.  However, there is conflicting evidence regarding this timeframe – some authors suggesting 2 hours other 24 hours. This report looks at the evidence surrounding the use of lactate as a biochemical marker for clinicians. It also examines evidence surrounding lactate clearance and it’s importance. The report also highlights some of the issues when examining studies completed on adults and then applied to children. No evidence was found to on studies completed on children with major trauma and lactate.

In order to gain to some insight into the usefulness of lactate in children, the evidence was examined surrounding septic shock. Again, there is a clear correlation between a raised lactate and increased mortality and morbidity. However, it must be remembered that the pathophysiology of septic shock is different to the pathophysiology of hypovolaemic shock, and therefore call into question the applicability of the evidence.

From the literature searched and presented it is clear that there is a gap in the knowledge of the usefulness of lactate in paediatric trauma. From this an evolving research question is given and an outline of a research proposal is discussed.