الفهرس 
Physiology of Acid Base Balance In Adults And PediatricsOnly 14 pages are availabe for public view
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Abstract
Lactic acidosis is not a disease but a phenomenon that occurs in association with a number of serious disorders, which cause considerable morbidity and mortality. The production of lactic acid is not pathological. Rather, it is a vital source of necessary ATP both at its site of production and for distant tissues. (Hood, 2005)
Disorders of acid-base balance can be found in as many as nine of every ten patients in the ICU , which means that acid-base disorders may be the most common clinical problems you will encounter in the ICU. Aberrant lactate metabolism is frequently encountered among critically ill patients. The overall incidence of lactic acidosis in critically ill patients is unknown; however, increasing acid-base evaluations of critically ill patients indicate its persistence increases associated morbidity and mortality. (Marino 2007)
Lactic acidosis is probably the most common cause of severe metabolic acidosis encountered in the intensive care unit. The AG is always increased above baseline (normal lactate level is below 1.0 mmol per L), because lactate does not appear in the urine until a higher plasma concentration is achieved, the tubular threshold being 6 to 8 mmol per L. Lactate levels greater than 5 mmol per L are considered diagnostic of lactic acidosis, although levels between 2 and 5 mmol per L may be significant in the appropriate clinical circumstances. (Robert and Gary, 2008)
Metformin, a biguanide commonly used in the treatment of type II diabetes mellitus, can cause of lactic acidosis, particularly in patients who have presented typically with acute or chronic renal insufficiency. Hemodialysis has been used in the treatment for metformin-induced acidosis. This medication is generally discouraged in patients with chronic renal insufficiency. (Nyirenda et al., 2006)
In clinical practice, separation of types A and B lactic acidosis is usually not helpful, because many critically ill patients have combined abnormalities. Increased lactate formation from tissue hypoxia and decreased lactate clearance often occur together. (Cooper and Alistair, 2009)
Because thiamine deficiency may be common in critically ill patients, this diagnosis should be considered in all cases of unexplained hyperlactatemia in the ICU. (Marino, 2007)
It is important to remember that, in healthy athletes, severe lactic acidosis during exercise is a normal, self-limited observation. (Rivers et al., 2001)