Abstract
INTRODUCTION: Hydrogen ion concentration which is expressed as pH value is in human blood maintained in narrow physiological range (7.36-7.44 in arterial blood). This range is crucial for normal functioning of most biochemical reactions. Extreme acidosis with pH < 6.8 is incompatible with life, unless pathophysiologic process is rapidly reversed. Timely, standardized, and structured approach to assessment and management of extreme critical illness is essential to maximize the chances of patient's survival. CASES: We present a series of 3 critically ill patients admitted to Medical intensive care unit (MICU) diagnosed with extreme metabolic acidosis (pH ⩽ 6.8). Each patient was treated using Checklist for Early Recognition and Treatment of Acute Illness and INjury (CERTAIN) which is a standard decision support tool in our MICU. Causes of extreme metabolic acidosis included hemorrhagic shock, sepsis, and acute renal failure and diabetic ketoacidosis. Rapid assessment, prompt resuscitation (IV fluids, vasopressors, mechanical ventilation, and renal replacement), and application of specific causal treatment led to positive outcomes in all 3 patients. DISCUSSION: Medical physiology textbooks set the lower limit of pH value at which life is possible to 6.8. However, examples from clinical practice show that if adequate resuscitation measures are taken early in the acute phase of the disease, the biochemical cascade of reactions that are considered irreversible (at pH ⩽ 6.8) may be reversed after all. CONCLUSION: Critical care approach to extreme metabolic acidosis is a prime example of applied clinical physiology where basic science and clinical practice connect. With these case series we show that timely and structured approach to critical illness shifts the boundaries of reversibility for some of the most severe physiologic derangements.