I caught up with Prof Tim Rainer who will be presenting a keynote at the Rwanda Emergency Care Association’s conference this May. Tim is Professor of Emergency Medicine at the Cardiff University School of Medicine. I asked Prof Rainer for a sneak peek into his keynote topic on permissive hypotension in the context of major trauma
What is Permissive Hypotension and why is it important?
Permissive hypotension, in its simplest form, is the use of restrictive fluid therapy that increases systemic blood pressure without reaching normal pressures. The aim is to achieve a mean arterial pressure of 40 to 50 mmHg, which is generally equivalent to a systolic blood pressure of ≤ 80mmHg, or the presence of a just palpable radial pulse.
There is a more complex definition, which is the use of restrictive fluid therapy and/or inotropes and/or vasopressors as appropriate to increase systemic blood pressure without reaching normal pressures. This definition is important practically as hypotension is not always due to hypovolaemia (or reduced preload) but may also be due to altered cardiac inotropy and/or peripheral vasodilatation.
The subject is important because there is considerable uncertainty regarding whether permissive hypotension is more or less appropriate than normotensive resuscitation, and whether this might impact on patient survival.