Table of Contents

The IUPAC definition incorporates both the Brønsted and the Lewis models of acids and bases. Thus, an acid is "a molecular entity or chemical species capable of donating a hydron (proton) or capable of forming a covalent bond with an electron pair." The two models are complimentary, and coexist easily in the complex minds of chemists, as they are useful for different situations.

The acidity of your precious bodily fluids is a carefully guarded parameter. To allow this parameter to deviate out of a very narrow range would massively impair your capacity to continue living. Basic molecular services would break down. Cellular anarchy would ensue. In order for the ICU physician to wrest a form of order from this chaos, a reasonable grasp of basic acid-base chemistry is expected. An excellent medically themed foundation for acid-base chemistry is laid by Kerry Brandis in a highly acclaimed series of online articles, to which I will constantly refer. It is not my intention to supercede this resource, as it remains canonical for all critical care trainees.