Metabolic Acidosis

The main causes of metabolic acidosis are excessive acid production, inappropriate urinary loss of bicarbonate, or failure of the kidney to excrete fixed acid. Although the Henderson-Hasselbalch equation provides mathematical information concerning the equilibrium of bicarbonate species, in practice it provides little information regarding the nature of the underlying cause of the acid-base disorder and the concept of 'anion gap' is useful in assessing the cause of metabolic acidosis. This is derived from the principle of electroneutrality and is calculated thus:

The anion gap represents an artificial disparity between the concentrations of these cations and anions routinely measured in clinical practice, therefore signifying the concentration of unmeasured anions such as proteins (the most important in healthy subjects), sulfate, phosphate, and others. The normal anion gap is 10-18mmoll—1 although recent calculations using more sensitive measurements estimate this to be 6-12mmoll—1. This concept has limitations but is useful for dividing metabolic acidoses into those characterized by an increased anion gap as a marker of excess generation of organic acids and those with a normal anion gap due to decreased excretion of acid or external losses of bicarbonate. There are exceptions to this rule, e.g., the acidosis of chronic renal failure, but, nonetheless, it remains a useful concept in clinical practice. Classification of the causes of metabolic acidoses according to the presence of an increased or normal anion gap is shown in Table 4.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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