Introduction: Critical illness is an emergency because the inflammatory response has redundant multiple pathways; once triggered, it is difficult to control or suppress. Infection is a potent precursor of critical illness and increasing organ dysfunction has a synergistic, rather than purely additive, adverse effect on mortality. The longer the inflammatory process continues unabated, the more advanced and unrecoverable the pathophysiological processes become resulting in a high mortality.
Methods: The review is a statement of the author's opinion supported by selected references. The content of the review was presented as the Tutor Edwards Lecture at The Royal College of Surgeons of England in December 2004.
Results: Critical illness is preceded by prodromal signs warning of impending physiological catastrophe. These simple physiological signs, the most sensitive of which is the respiratory rate can be quantified using Early Warning Scores. If patients trigger the Early Warning Score, emergency management is required to reverse the abnormal physiological decline or to prompt admission to a critical care area. The emergency management principles include removal or reversal of the cause so shutting down the inflammatory response, appropriate antibiotic therapy and general organ support.
Conclusions: Formalising measurement of physiological (in)stability on the general ward using Early Warning Scores improves recognition of unstable and potentially critically ill patients. Prompt intervention will either reverse further physiological decline or facilitate timely referral to the critical care service for further, more invasive, organ support.