Myocardial Hypo-perfusion in Trauma with Robbie Lendrum

In this session I am speaking with Robbie Lendrum on the Myocardial Hypoperfusion & injury in Trauma. We examine the Windkessel concept of pulsatile flow to constant flow, reservoir pressure as an analogue of diastolic pressure, coronary perfusion in diastole. We also explore blood pressure targeted intervention, the disparity between NIBP and IBP, the precision of diagnostics versus intervention, and individually patient centred intervention. We finally fundamentally drill down into the true importance of diastolic blood pressure in trauma care and how this is a succinct shift in mindset and teaching to traditional systolic blood pressure measurements and cut offs.

To do this I have Robbie Lendrum with me. Robbie is a consultant in cardiac anaesthesia and critical care. He is also a consultant in Pre-Hospital Care working with London’s Air Ambulance. Robbie is an honorary senior lecturer at Queen Mary university London and an Endovascular Resuscitation Researcher within the UK. Within the conversation we also examine:

• Cardiac hypoperfusion – pathophysiology
• The Windkessel concept – converting pulsatile flow into constant flow, the generation of pressure.
• Reservoir pressure equal to diastolic pressure
• Coronary perfusion in diastole and the fundamental importance of diastole in trauma 
• Arterial injury and respective diastolic hypotension – wide pulse pressures  - Effect on coronary perfusion pressure & flow
• CVD – Cardiovascular Dysfunction with early death/72 hour boundary.
• Physiological targets (targeted intervention)
• Why should we move on from blood transfusion and drive faster to hospital. 
• The secondary effects on the heart & essentially outcome.
• Arterial shock and the proximal thoracic aorta.
• The two main types of patient and how we approach these (Tamponade and exsanguination)

My thanks to Robbie for this interview. This is a fundamental shift in teaching and mindset and is seminal in how we see and approach trauma care in the future. The key pieces of research that Robbie mentions in the interview includes: 

Importance of the aortic reservoir in determining the shape of the arterial pressure waveform. The forgotten lessons of Frank. https://www.sciencedirect.com/science/article/abs/pii/S187293120700155X

The Underlying Cardiovascular Mechanisms of Resuscitation and Injury of REBOA and Partial REBOA

https://pubmed.ncbi.nlm.nih.gov/35615678/

Trauma Laparotomy in the UK: A Prospective National Service Evaluation

https://pubmed.ncbi.nlm.nih.gov/34015456/

My thanks to Robbie for his insights and reflections.