London Calling – part 3
The highlight for me was Mr Jonny Morrison speaking on Resuscitative Emergency Balloon Occlusion of the Aorta (REBOA). He is a British military surgeon currently out in Texas studying balloon occlusion of the aorta on pigs. Looking at trauma deaths, the next unexpected survivors will come from the uncontrollable haemorrhage group (truncal and junctional zones). This is by no means a new technique – described in the 1950’s during the Korean War – but like the early Star Wars chapters, needed to wait for technology to advance to make it feasible. It has the effect of cross clamping the aorta which provides afterload support, increases cerebral and coronary perfusion and provides proximal inflow control – without the mess of a resuscitative thoracotomy and greater access.
The placement of the balloon is determined by the location of the injury (see photo) and falls into two zones. Zone 1 is the thoracic aorta and is used for truncal haemorrhage control, avoid Zone 2 where the celiac axis etc originates and Zone 3 is infrarenal, used for junctional bleeding and pelvic haemorrhage.
His studies have determined that for Zone 3 amenable bleeds balloon occlusion up to 60min is the optimal time. Any longer and the debt of the metabolic load is paid by increased inotropic support requirements. He also compared REBOA to the current standard treatment for junctional injuries, Celox™ gauze. If coagulation is normal then both treatments perform similarly, the benefit is seen in coagulopathic patients where REBOA outperforms the gauze.
Has REBOA been used on humans? Yes a case series of 13 – the technique improved the BP allowing time to get to definitive surgery (blogged here 2.5 years ago!).
The Zone 1 studies are looking at continuous vs intermittent balloon occlusion. The jury is still out as to which is better. With the intermittent occlusion (20min on, 1min off) there are inevitably some losses when the balloon is deflated, conversely the metabolic debt generated by continuous occlusion is too great in some also leading to deaths.
What was very clear is that for this technique to have an impact it must be delivered proactively and pre-hospital. The challenges that need to be overcome are access to the femoral artery and blind accurate placement.
Prof Karim Brohi brought the conference to a close with a summary of what we have learned about coagulation in trauma this year. Here are three things;
- FFP is good but as 43% deaths due to trauma in the UK are secondary to bleeding and occur in the first 3hr we are failing our patients by administering the treatment on average at 2.5hrs.
- Fibrinogen levels are low in coagulopathic trauma patients; we should give cryoprecipitate early and aim for Fib ≥2.0
- And finally whilst TEG is recommended to guide treatment and can provide results within 5 min, there are some aspects of coagulation it does not detect i.e. fibrinolysis was only detected in 8% of coagulopathic trauma patients – when measured in the plasma it was then detectable in 80%.
These are the highlights of the 2012 London Trauma Conference. I hope this whistle stop tour through these days has been informative and though provoking. I can assure you telephone hacking was not used to bring you this information and to my knowledge is correct.
This is Lou Chan, roving reporter for Resus ME! signing off.
‘London raises her head, shakes off the debris of the night from her hair, and takes stock of the damage done. The sign of a great fighter in the ring is can he get up from a fall after being knocked down… London does this every morning.’