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.