Fluid Physiology

A new look for 2021. This website is for physicians and physiologists who want resources and support to learn, to apply and to teach up-to-date fluid physiology. We also welcome contributions from the Pharmaceutical Industry and Equipment Manufacturers engaged in the field of fluid physiology and fluid therapy.  It is directed and moderated by Tom Woodcock M.Biol. Ph.D and Thomas Woodcock MB.BS M.Phil Med Law (Glasg).

In 2012 we offered “an improved paradigm for prescribing intravenous fluid therapy” (1) based on recent revisions to the traditional Starling principle explained by Professors Levick and Michel, a paper that is now essential reading for clinicians (2).

(1) Woodcock TE, Woodcock TM. Revised Starling equation and the glycocalyx model of transvascular fluid exchange: an improved paradigm for prescribing intravenous fluid therapy. Br J Anaesth. 2012;108:384-394.

(2) Levick JR, Michel CC. Microvascular fluid exchange and the revised Starling principle. Cardiovasc Res. 2010;87:198-210.

We have since published several peer-reviewed papers and a Textbook, plus YouTube Education.


If you search The Starling Principle or Starling equation or capillary fluid exchange you’ll find many enthusiastic video bloggers, from medical students to professors, explaining the traditional filtration/ reabsorption concept. Some of them have enjoyed many thousands of views and hundreds of positive comments from students who have struggled to understand. Many of these videos seem to be aimed at candidates for the USMLE = United States Medical Licensing Examination. My experience with Examiners is that they give credit to candidates who answer correctly, even if they were expecting candidates to give a conventional but wrong answer. Here’s hoping USMLE Examiners are similarly flexible!

Fluidphysiology.org has been receiving visitors every day since inception; to date more than 37,500 views.

“Sub-optimal fluid therapy is costing patients their lives and causing tens of thousands of patients to suffer complications every year” Mike Stroud, NICE 2013

“everything we were taught about Starling’s forces at the capillary was wrong” UK Critical Care Research Forum 2016

“The challenge is to keep fluid in the intravascular space.”

“The Basics, reappraised.” Tom Woodcock 2012

“New opinions are always suspected, and usually opposed, without any other reason but because they’re not already common” John Locke, d.1704

“The chief object of education is not to learn things but to unlearn things”
G. K. Chesterton

“The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd; indeed in view of the silliness of the majority of mankind, a widespread belief is more likely to be foolish than sensible.”
Bertrand Russell


John Myburgh AO ‏@JAMyburgh Mar 5
@thomaswoodcock Please refer to my paper on Resuscitation Fluids in NEJM. Your paper on EGCX should be mandatory reading.

Gary Macy, Duke University Hospital. “I believe!”

Great project and topical – everything we were taught about Starling’s forces at the capillary was wrong http://t.co/LDTKH6h1Ms

PICS Trainee Reps
“@jez_tong: One of the most important papers out on fluid theory: #glycocalyx http://t.co/XgoK29KlrK #FOAMed #CriticalCare” #PICMustReads

Dr Pnt Laloë
Via Shaman Jhanji at CPD day. Just reminded us about this great glycocalyx & Starling BJA paper by Woodcock. http://t.co/VoivSX0dtp

Your review on revised Starling in Br J Anaesth 2012 really impressed me and excited my interest in fluid therapy in critical illness.


Rob Mac Sweeney        @CritCareReviews

@thomaswoodcock @Fluid_Academy it’s a message to be spread.
Lots of interest in human CC from vets too – many following CCR for updates
08:55 PM – 25 Sep 16