Forgotten physiology

John A Myburgh

Sydney

Dario Maestrini1886-1975

Legge dei cuore: 1914

The mechanical energy set free in the passage from the resting to the active state is a function of the length of the fibre.

Ernest Starling1866-1927

Otto Frank1865-1944

Georg Ohm1789-1854

Die galvanische Kette, mathematisch bearbeitet: 1927

Q

P

W Q

Georg Ohm1789-1854

WR Q

V

Rivers: NEJM 2001

Zhang: Trials 2013

Arthur Guyton 1919-2003

Mean arterial pressure

Cardiac output Right atrialpressure

Mean systemic pressure

Perfusion pressure

Unstressedvolume

Stressedvolume

Venous return

Arteriolar tone

15mmHg15mmHg

5mmHg

60mmHg

60mmHg

Right atrial pressure (mmHg)0

10

Venous return

l/min

Cardiac function

Mean systemic pressure

Guyton

CO = VR = (Pms – RAP) / RVRStarling

MAP Volume

Stroke volume

ImpedanceCardiac

RAP ANS

P= Vs / C

The physiological fallacyBased on a common phenotype and surrogate variables

Assumes an inference, that cannot be measured, that the patient has inadequate organ blood flow.

Assumes a second inference, that also cannot be measured, that a single intervention will restore the complexity of altered haemodynamics in a predictable and safe fashion for the duration of the illness.

Drug:  A term of varied usage. In medicine, it refers to any substance with the potential to prevent or cure disease or enhance physical or mental welfare. (www.WHO.int)

John Maynard Keynes1883-1946

The difficulty lies, not in new ideas, but in escaping old ones, which ramify, for those brought up with them, as most of us have been, into every corner of our minds.