Dr Simon Mercer, Aintree University Hospital
The meeting was opened by Dr Christine Bell, Immediate Past-President because Dr Fazackerley would arrive late due to a family commitment. Dr Bell introduced the speaker, Dr Simon Mercer, a consultant anaesthetist at Aintree University Hospital and a Surgeon Commander in the Royal Navy.
Dr Mercer started his talk by highlighting two recent reports; the first was the NCEPOD report of 2007 ‘Trauma: Who Cares?’ and the second was a recent document by the Care Quality Commission reviewing compliance of their original 2008 report about the Defence Medical Services. The former document had underlined the shortcomings of the trauma service within the National Health Service. The latter highlighted the quality of care which had come from frontline experience in Iraq and Afghanistan.
Dr Mercer looked at the method of trauma management within the military service as performed in Afghanistan. He said that catastrophic haemorrhage was the commonest cause of death often caused by the use of improvised explosive devices (IEDs) which were planted and remotely detonated. He showed some statistics demonstrating how, over the last 10 years, deaths due to IEDs had increased to 60% of all fatalities. Therefore it is important to gain control of massive haemorrhage as quickly as possible. This starts at the point of injury where first aid is administered, for example, in the form of Celox gauze which is impregnated by haemostatic granules promoting rapid coagulation in life threatening bleeding.
Dr Mercer then went through the military trauma patient pathway. This commenced with a “9 Liner” summoning the medical emergency response team (MERT) starting the evacuation process of an injured combatant. This team would be led by either a consultant anaesthetist or emergency department physician. On their arrival they would begin the process of damage control resuscitation with the aims of minimising blood loss and maximising tissue oxygenation to optimise outcome. This included initial permissive hypotension, haemostatic resuscitation and airway control. This would be continued during transfer to Camp Bastion for rapid damage control surgery. Dr Mercer emphasized the change from the traditional approach of resuscitation first followed by surgery where now resuscitation and surgery were performed concurrently.
Dr Mercer spoke about the lethal triad of acidosis, hypothermia and coagulopathy. This was avoided by the emphasis on flow rather than pressure; therefore vasopressors were rarely used particularly in this population of patients who had no stenotic vessels. He commented that the base deficit had been found to be the most accurate measure of tissue perfusion.
Dr Mercer then talked about the use of blood products and how practice again had changed. Traditional transfusion had focused primarily on red cells with relatively lower quantities of fresh frozen plasma administration. There was good evidence that using a ratio of 1:1 significantly improved mortality. Dr Mercer commented that there was increasing evidence that tissue hypo-perfusion lead to a primary coagulopathy which further worsened outcome.
Dr Mercer then looked at Tranexamic acid which had been demonstrated to significantly reduce all-cause mortality in trauma patients with significant haemorrhage in the CRASH II Trial. It was therefore now routinely used for military casualties. Another factor that improved outcome was the use of fresh rather than old units of red blood cells during the first 24 hours.
Dr Mercer then went through the activation criteria for the trauma team and looked at its make-up. This included seven senior doctors as well as nurses, ODPs, a radiographer, a laboratory technician and a scribe. He likened the function of this trauma team to a Formula One pit stop team where everybody knew exactly what their role was. He then compared this with the Aintree trauma team which had one senior doctor leading a much smaller number of trainees and nurses.
Dr Mercer discussed the way that the team prepared for a casualty. This included checks on equipment, ensuring all members knew their roles, drawing up and calculating drug doses and ensuring shock packs were available. On arrival, there would be a brief handover (ATMIST) where the Age of the patient, Time of injury and its Mechanism, the Injuries sustained, Signs and symptoms such as whether they had been already intubated and ventilated and Treatment given such as tourniquets applied or analgesia, further drugs and blood transfusion administered. Once the patient was brought in to the admission unit, team members would be working concurrently. A primary survey would be carried out; anaesthetists would be confirming the placement for the endotracheal tube and maintaining anaesthesia whilst continuing haemostatic resuscitation. X-rays would be taken and orthopaedic surgeons would be assessing the extent of the wounds. This would all happen within the first 15 minutes when a decision would then be made to take the patient for a CT traumogram or straight to theatre for damage control surgery. If a CT was undertaken a report would be immediately available so that surgery could be rapidly planned.
Dr Mercer then looked at the theatre team for a complex trauma. This may include 2 anaesthetists and ODPs, 4 orthopaedic surgeons, 2 general surgeons and a plastic surgeon with all the support staff. He stressed the importance of anaesthetic leadership, seeing what all of the team members were doing and communicating and reacting to any concerns that they see. He highlighted the importance of the ROTEM machine in tailoring the requirement for individual clotting factors. He demonstrated the differences in the ROTEM curve when there was either platelet or fibrinogen deficiencies. He also stressed the importance of giving regular calcium to counteract the effects of the citrate load from blood products.
Dr Mercer spoke of the importance of communication during damage control resuscitation and surgery and it was normal to have formal communication among the team every 10 minutes to discuss the amount of blood products transfused, the state of coagulation and patient temperature as well as surgical progress. Surgery at this point was fairly basic and far from definitive with the primary aim of controlling bleeding and excising any dead tissue.
Following the termination of damage control surgery the patient would be transferred to critical care prior to evacuation within 24 hours by air to Queen Elizabeth Hospital Birmingham. With this, his talk concluded.
There followed a number of questions. Professor Hunter asked if sometimes there were too many people at these resuscitations. Dr Mercer said that the role of the Medical Director was to ensure that only sufficient team members were deployed and indeed, one of his important jobs was crowd control. Dr Gray asked if the field hospital had ever been swamped by multiple casualties. To date this had not happened because of team allocations and triage prior to arrival. Other questions included the place of crystalloid in these resuscitations. Dr Mercer answered that they no longer had a place in the initial resuscitation as the principle cause of threat to life was blood loss and therefore blood products were primarily used. Once cardiovascular filling had been achieved there may then be a place for crystalloids. He commented that permissive hypotension was acceptable particularly in the field prior to arrival at the hospital base with the exception of the head injured patient as the use of vasopressors would impede flow. However, casualties would arrive at the field hospital within the first hour after injury where aggressive resuscitation during surgery would be performed.
Dr Alok Srivastava gave the vote of thanks and the meeting finished at 20:15.
20th November 2012