useful links


Stewart type acid-base analysis based sites

base excess centered analysis sites

bicarbonate centered analysis sites

an advanced attempt to synthetise it all:
The Border Flux Model

the parable of the blind men and the elephant


intensive care and emergency medicine ultrasound

a presentation about colloids (The 2nd Fluid Academy Day in Antwerpen, november 2012)

colloids 2011 - 2012

Yohannes George has made this excellent primer on Stewart's approach to acid base available to the public!

New download: Easy Way to Understand Stewart
"Most students consider the discussion of physiological acid-base balance a mystery.
This is mainly because of the way the topic has been presented.
At first reading of any text book on acid-base balance they realise that what they are reading is not consistent with chemistry previously learnt."
Michael Bookallil

acid base analysis in general

While not based on the Stewart approach, the late Michael Bookallil's online book about acid-base balance is worth while reading, and serves to remember that eccentric Sydney anaesthesiologist with a mind and a tongue sharp as a razor.
Michael Bookallil's ACIDBASE BALANCE
His account is especially lucid in its discussion of hypothermia and its significance in acid-base analysis and general physiology.

A general description and discussion of the different approaches to acid-base analysis is given by Deepa Bangalore and Janice L. Zimmerman
on the American College of Chest Physicians website.
This includes an extensive list of possible causes of acid-base disturbances.

Stewart type acid-base analysis based sites

There is a splendid book on acid base and fluid physiology by Kerry Brandis, explaining both the traditional and the physicochemical analysis, known as the Stewart approach:
acid base and fluid physiology
The physicochemical approach is discussed in detail in chapter 10:
the concept of strong ion difference

This exhaustive site dedicated to the physicochemical approach features a java based acid base calculator, based on the Stewart approach:
authored chiefly by Lara Hopley and Jo van Schalkwyk.
Here you can make clear graphs showing the effects of the different components on the acidity of a solution.

James Figge, one of the original researchers in this field, closely linked to Peter Stewart's and Vladimir Fencl's work presents a detailed account of the weak acids, especially albumin and its experimental validation on
the Figge - Fencl - website,
as well as a tribute to the late Vladimir Fencl.

John Kellum of Pittsburgh university is one of the most prominent proponents of the Stewart approach. His web pages give a concise introduction to the topic with clinical examples and the possibility to download a pH and acidbase calculator spreadsheet.
John Kellum's phorum website

The following is a presentation about respiratory physiology, with special regard to respiratory drive under conditions of height, pregnancy etc., with acid-base considerations based on the Stewart model:
Carriage of oxygen and carbondioxide in blood

The late Peter Lloyd's Stewart-based acid-base calculator and its clinical utility are presented with many illustrative examples in
Using Quantitative Acid-Base Analysis in the ICU
Peter Lloyd's website offering to download the spreadsheet based calculator mentioned in his publication can no longer be accessed, though, but we have got permission to put it up for download on our site. this is "what Peter would want", according to his mother. Please go to the download page to get this spreadsheet calculator and the article about how to use it!

Philip D. Watson's website offers his AcidBasics II software and quite a bit of related information. This very illustrative software offers simulating the acid-base effects of changing solute values in different media, not only in plasma, but also in urine, sea water or a cell culture medium. It also allows for calculating the effects of changing temperature and buffer therapy. (The software is only available for microsoft windows, but it can be run under linux with the help of wine.)
the AcidBasics II website

AcidBasics - Part 3 of a fun primer on fluids, electrolytes and acid-base therapy for intensive care professionals, by Tom Woodcock. 3-acid basics

inspite of the often acerbic rethoric, reminiscent of religious controversies, not all is dismal disagreement between the different approaches to acid-base, though!

base excess centered analysis sites

on the Siggaard-Andersen homepage you will find a rich source of information about acid-base and blood gases:
the Siggaard-Andersen homepage
(go to the sections on "buffer base" and the "van Slyke formula" to see the parallels between the approaches!)

another excellent website about the BE approach (critical of the Stewart approach, even though in a respectful way .... ):
Alan W. Grogono's homepage.

bicarbonate centered analysis sites

there is another excellent website and tutorial about the bicarbonate-based variant of acid-base analysis is
Timur Graham's site at the University of Connecticut.

the bicarbonate approach, also called the "physiological approach", is well described by Adrogué, even though he has little good to say about our favourite theory:
a recent article by Adrogué
Adrogué HJ, Gennari FJ, Galla JH, Madias NE; Assessing acid-base disorders; Kidney Int 2009 Oct 7

The Border Flux Model

by Jirí Kofránek, Stanislav Matousek, Michal Andrlík from Charles University in Prague.
This is a very interesting approach making a synthesis of Stewart type thinking and the bicarbonate centred approach. The theory is explained in the article about the border flux approach, an online simulator can be used at the authors' website.

finally: the blind men and the elephant

the elephant parable